U.S. patent application number 13/763485 was filed with the patent office on 2013-06-20 for electronic endoscope.
This patent application is currently assigned to FUJIFILM CORPORATION. The applicant listed for this patent is FUJIFILM CORPORATION. Invention is credited to Kenji Yamane.
Application Number | 20130155214 13/763485 |
Document ID | / |
Family ID | 41434090 |
Filed Date | 2013-06-20 |
United States Patent
Application |
20130155214 |
Kind Code |
A1 |
Yamane; Kenji |
June 20, 2013 |
ELECTRONIC ENDOSCOPE
Abstract
An electronic endoscope includes a lens holder that has a
tube-shaped part, a wide-angle lens that is mounted on the lens
holder and that is arranged on one-end side of the tube-shaped part
in a state that an optical axis is aligned to a center axis of the
tube-shaped part so that an observational field of view extends to
a sideward region of the tube-shaped part, an imaging device that
receives light acquired through the wide-angle lens and that
converts the light into an electric signal, a transparent cover
that covers one-end side of the tube-shaped part and whose part
facing the observational field of view of the wide-angle lens has
transparency, a tube-shaped body part that is connected to the
transparent cover on the-other-end side of the tube-shaped part,
and a driving section that causes the lens holder to advance or
retreat in the center axis direction.
Inventors: |
Yamane; Kenji;
(Ashigarakami-gun, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
FUJIFILM CORPORATION; |
Tokyo |
|
JP |
|
|
Assignee: |
FUJIFILM CORPORATION
Tokyo
JP
|
Family ID: |
41434090 |
Appl. No.: |
13/763485 |
Filed: |
February 8, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
12999815 |
Dec 17, 2010 |
|
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PCT/JP2009/060885 |
Jun 15, 2009 |
|
|
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13763485 |
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Current U.S.
Class: |
348/65 |
Current CPC
Class: |
A61B 1/042 20130101;
A61B 1/05 20130101; A61B 1/00183 20130101; A61B 1/00096 20130101;
A61B 1/00177 20130101; A61B 1/045 20130101; H04N 7/18 20130101;
A61B 1/00172 20130101 |
Class at
Publication: |
348/65 |
International
Class: |
A61B 1/05 20060101
A61B001/05 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 17, 2008 |
JP |
2008-157991 |
Jun 17, 2008 |
JP |
2008-157992 |
Jun 17, 2008 |
JP |
2008-157993 |
Jun 17, 2008 |
JP |
2008-157999 |
Jun 17, 2008 |
JP |
2008-158000 |
Jun 17, 2008 |
JP |
2008-158002 |
Jun 17, 2008 |
JP |
2008-158004 |
Jun 17, 2008 |
JP |
2008-158005 |
Jun 17, 2008 |
JP |
2008-158006 |
Jun 17, 2008 |
JP |
2008-158013 |
Claims
1. An electronic endoscope that is inserted into a subject and then
acquires an image inside the subject, comprising: a lens holder
that has a tube-shaped part; a wide-angle lens that is mounted on
the lens holder and that is arranged on one-end side of the
tube-shaped part in a state that an optical axis is aligned to a
center axis of the tube-shaped part so that an observational field
of view extends to a sideward region of the tube-shaped part; an
imaging device that receives light acquired through the wide-angle
lens and that converts the light into an electric signal; a
transparent cover that covers one-end side of the tube-shaped part
and at least whose part facing the observational field of view of
the wide-angle lens has transparency; a tube-shaped body part that
is connected to the transparent cover on the-other-end side of the
tube-shaped part; and a driving section that is arranged inside the
body part and that causes the lens holder to advance or retreat in
the center axis direction, wherein the driving section includes: a
feed screw which is supported inside the body part in a revolvable
manner in parallel to the optical axis direction of the wide-angle
lens; a feed nut which is fixed to the lens holder in a screwed
manner onto the feed screw; and a motor which drives and revolves
the feed screw, and wherein revolution of the lens holder about the
feed screw as an axis of revolution is restricted.
2. The electronic endoscope according to claim 1, wherein the
imaging device receives light from an entire sideward circumference
of a direction of insertion into the subject.
3. The electronic endoscope according to claim 1, wherein the
wide-angle lens comprises a circular fish-eye lens.
4. The electronic endoscope according to claim 1, comprising: a
half mirror that is arranged in a course of an optical path between
the wide-angle lens and the imaging device; and a light emitting
body that emits light for illumination to be projected through the
wide-angle lens after reflection by the half mirror and thereby
illuminates a subject.
5. The electronic endoscope according to claim 1, wherein the
tube-shaped part of the lens holder and a tip part of the
transparent cover that covers the tube-shaped part are formed in a
smaller diameter than the body part.
6. The electronic endoscope according to claim 1, wherein a control
section that performs image processing on an image signal obtained
by image pick-up performed by the imaging device and an image
memory that stores image data obtained by image processing
performed by the control section are built inside the body
part.
7. The electronic endoscope according to claim 1, wherein a power
battery for supplying electric power to the imaging device and the
driving section is built inside the body part.
Description
[0001] The present application is a Continuation application of
U.S. patent application Ser. No. 12/999,815, having a .sctn.371(c)
date of Dec. 17, 2010, which was based on PCT/JP2009/060885 filed
on Jun. 15, 2009, which is based on and claims priority from
Japanese patent application Nos. 2008-157991, 2008-157992,
2008-157993, 2008-157999, 2008-158000, 2008-158002, 2008-158004,
2008-158005, 2008-158006, and 2008-158013 filed on Jun. 17, 2008,
the entire contents of which is incorporated herein by
reference.
TECHNICAL FIELD
[0002] The present invention relates to an electronic
endoscope.
BACKGROUND ART
[0003] In an electronic endoscope described in Patent Document 1,
an insert part of a small diameter is inserted into a hole or an
abdominal cavity so that an objective lens attached at the tip of
the insert part is directed to a diseased part or the like in the
direction of insertion. Then, in this state, image information is
acquired.
[0004] Further, in an electronic endoscope described in Patent
Document 2, an objective lens is provided in a side surface of the
tip part of an insert part. Thus, an image is acquired within the
field of view extending sideward.
[0005] Further, in an electronic endoscope described in Patent
Document 3, an omnidirectional light receiving unit is provided at
the tip of an insert part so that an image covering the entire
circumferential directions at the tip of the insert part is
acquired using reflection by a convex mirror provided inside the
omnidirectional light receiving unit.
[0006] Further, an electronic endoscope described in Patent
Document 4 is of capsule type used for medical checkup of the
alimentary canal in the medical field. This electronic endoscope
has an imaging device in the inside, and hence continuously
performs image pick-up of the inside of the alimentary canal in the
course that the electronic endoscope is conveyed along the inside
of the alimentary canal in association with peristaltic motion of
the alimentary canal.
[0007] In many cases, the imaging device accommodated in the tip
part of such an electronic endoscope has a smaller area and a
smaller number of pixels than a solid-state imaging device used in
a digital camera or the like. Thus, when a detailed image of a
diseased part or the like is acquired, the image information
obtained by each single image pick-up is limited to the image of a
small view field region.
[0008] Thus, when detailed image information is to be acquired over
a large region, the operator of the electronic endoscope need
repeat image pick-up multiple times with adjusting the insertion
position of the electronic endoscope by manual operation. Thus,
attention need be paid to both of the operation of searching a
diseased part or the like, that is, adjusting the insertion
position, and the operation of image taking. Thus, skill has been
necessary in such work.
[0009] Further, in the electronic endoscope in which an image over
the entire circumference of the tip of the insert part is acquired
using an omnidirectional light receiving unit, image information
over the entire circumference region of the insertion position
where image pick-up is performed is obtained at once. Nevertheless,
the image pick-up region is restricted to a region of a narrow
width at the insertion position. Thus, in order that entire
circumferential image information should be acquired over a large
region, image pick-up need be repeated in such a manner that the
insertion position is adjusted at each time. This causes a
possibility that information is missing at a junction part of
images or that useless image pick-up is repeated.
[0010] Further, the electronic endoscope of capsule type is
conveyed along the inside of an alimentary canal by peristaltic
motion of the alimentary canal. Thus, the operation of moving the
field of view is unnecessary. Nevertheless, such an electronic
endoscope is not applicable to a hole or an abdominal cavity where
peristaltic motion is absent.
CITATION LIST
Patent Literatures
[0011] Patent Document 1: Japanese Laid-Open Patent Publication No.
H09-192084 [0012] Patent Document 2: Japanese Laid-Open Patent
Publication No. H03-191944 [0013] Patent Document 3: Japanese
Laid-Open Patent Publication No. 2003-279862 [0014] Patent Document
4: Japanese Laid-Open Patent Publication No. H09-327447
SUMMARY OF INVENTION
Technical Problem
[0015] An object of the present invention is to provide an
electronic endoscope that has a new structure for realizing easy
and accurate acquisition of detailed image information over a large
region.
Solution to Problem
[0016] (1) An electronic endoscope characterized in that an outer
shell that is formed in a tube shape and whose peripheral wall is
provided with a transparent window part extending in an axial
direction; a solid-state imaging device that is provided inside the
outer shell; an objective optical system that includes an objective
lens for focusing object light through the window part and that
forms an image onto the solid-state imaging device; and a drive
mechanism that causes at least the objective lens in the objective
optical system to move along an axis of the outer shell.
[0017] (2) An electronic endoscope that is inserted into a subject
and then acquires an image inside the subject, characterized in
that a lens holder that has a tube-shaped part; a wide-angle lens
that is mounted on the lens holder and that is arranged on one-end
side of the tube-shaped part in a state that an optical axis is
aligned to a center axis of the tube-shaped past so that an
observational field of view extends to a sideward region of the
tube-shaped part; an imaging device that receives light acquired
through the wide-angle lens and that converts the light into an
electric signal; a transparent cover that covers one-end side of
the tube-shaped part and at least whose part facing the
observational field of view of the wide-angle lens has
transparency; a tube-shaped body part that is connected to the
transparent cover on the-other-end side of the tube-shaped part;
and a driving section that is arranged inside the body part and
that causes the lens holder to advance or retreat its the center
axis direction.
[0018] (3) An electronic endoscope characterized in that a
cylindrical transparent cover at least whose observation window in
a cylindrical part is transparent; a body past that has a
cylindrical part provided continuously to the cylindrical part of
the transparent cover; a lens holder that revolves about a center
axis of the transparent cover in an inside of the transparent cover
and the body part and that moves in a direction of the center axis;
an objective mirror that is provided in the lens holder and that
reflects, toward the body part, light entering through an objective
lens provided at a position facing the cylindrical part of the
transparent cover; an imaging device that receives light reflected
from the objective mirror and that converts the light into an
electric signal; and a driving section that is provided inside the
body part and that drives and revolves the lens holder so as to
drive the lens holder in the center axis direction.
Advantageous Effects of Invention
[0019] According to the present invention, detailed image
information over a large region is acquired easily and
accurately.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 is an external appearance perspective view of an
example of an electronic endoscope used for describing an
embodiment of the present invention.
[0021] FIG. 2 is a longitudinal sectional view of an electronic
endoscope shown in FIG. 1.
[0022] FIG. 3 is an exploded perspective view of an electronic
endoscope shown in FIG. 1.
[0023] FIG. 4 is an enlarged perspective view of an image pick-up
drive unit part that contains a solid-state imaging device in an
electronic endoscope shown in FIG. 1.
[0024] FIG. 5A is a perspective view used for describing operation
of a lens holder for holding an objective lens in an electronic
endoscope shown in FIG. 1.
[0025] FIG. 5B is a perspective view used for describing operation
of a lens holder for holding an objective lens in an electronic
endoscope shown in FIG. 1.
[0026] FIG. 6A is a perspective view used for describing a driving
section for moving a lens holder for holding an objective lens in
an electronic endoscope shown in FIG. 1.
[0027] FIG. 6B is a perspective view used for describing a driving
section for moving a lens holder for holding an objective lens in
an electronic endoscope shown in FIG. 1.
[0028] FIG. 7 is a partly sectional perspective view of a driving
section shown in FIG. 6A.
[0029] FIG. 8 is a functional block diagram showing an electronic
endoscope shown in FIG. 1.
[0030] FIG. 9 is a control flow chart of an electronic endoscope
shown in FIG. 1.
[0031] FIG. 10 is a schematic diagram showing an image map
generated by an electronic endoscope shown in FIG. 1.
[0032] FIG. 11 is an external appearance perspective view of
another example of an electronic endoscope used for describing an
embodiment of the present invention.
[0033] FIG. 12 is a longitudinal sectional view of an electronic
endoscope shown in FIG. 10.
[0034] FIG. 13 is an exploded perspective view of an electronic
endoscope shown in FIG. 10.
[0035] FIG. 14 is a sectional view used for describing a view field
region in an electronic endoscope shown in FIG. 10.
[0036] FIG. 15 is a schematic diagram showing an image map
generated by an electronic endoscope shown in FIG. 10.
[0037] FIG. 16 is an external appearance perspective view of
another example of an electronic endoscope used for describing an
embodiment of the present invention.
[0038] FIG. 17 is a longitudinal sectional view of an electronic
endoscope shown in FIG. 16.
[0039] FIG. 18 is an exploded perspective view of an electronic
endoscope shown in FIG. 16.
[0040] FIG. 19 is a perspective view used for describing a driving
section for moving a lens holder for holding an objective lens in
an electronic endoscope shown in FIG. 16.
[0041] FIG. 20 is a longitudinal sectional view used for describing
operation of a lens holder for holding an objective lens in an
electronic endoscope shown in FIG. 16.
[0042] FIG. 21 is a longitudinal sectional view used for describing
operation of a lens holder for holding an objective lens in an
electronic endoscope shown in FIG. 16.
[0043] FIG. 22 is a schematic diagram used for describing a view
field region in an electronic endoscope shown in FIG. 16.
[0044] FIG. 23 is an external appearance perspective view of
another example of an electronic endoscope used for describing an
embodiment of the present invention.
[0045] FIG. 24 is a longitudinal sectional view of an electronic
endoscope shown in FIG. 23.
[0046] FIG. 25 is an exploded perspective view of an electronic
endoscope shown in FIG. 23.
[0047] FIG. 26 is a longitudinal sectional view used for describing
operation of a lens holder for holding an objective lens in an
electronic endoscope shown in FIG. 23.
[0048] FIG. 27 is a longitudinal sectional view used for describing
operation of a lens holder for holding an objective lens in an
electronic endoscope shown in FIG. 23.
[0049] FIG. 28 is a schematic diagram used for describing a view
field region in an electronic endoscope shown in FIG. 23.
[0050] FIG. 29 is an external appearance perspective view of
another example of an electronic endoscope used for describing an
embodiment of the present invention.
[0051] FIG. 30 is a longitudinal sectional view of an electronic
endoscope shown in FIG. 29.
[0052] FIG. 31 is an exploded perspective view of an electronic
endoscope shown in FIG. 29.
[0053] FIG. 32 is a longitudinal sectional view used for describing
operation of a lens holder for holding an objective lens in an
electronic endoscope shown in FIG. 29.
[0054] FIG. 33 is a longitudinal sectional view used for describing
operation of a lens holder for holding an objective lens in an
electronic endoscope shown in FIG. 29.
[0055] FIG. 34 is an external appearance perspective view of
another example of an electronic endoscope used for describing an
embodiment of the present invention.
[0056] FIG. 35 is a longitudinal sectional view of an electronic
endoscope shown in FIG. 34.
[0057] FIG. 36 is an exploded perspective view of an electronic
endoscope shown in FIG. 34.
[0058] FIG. 37 is an enlarged perspective view of a part containing
an image pick-up drive unit part of an electronic endoscope.
[0059] FIG. 38A is an enlarged perspective view showing a situation
of movement of a lens holder inside a transparent cover in a state
that the lens holder is located at an upper end position.
[0060] FIG. 38B is an enlarged perspective view showing a situation
of movement of a lens holder inside a transparent cover in a state
that the lens holder is located at a lower end position.
[0061] FIG. 39A is an enlarged perspective view showing a main part
of a moving mechanism for a lens holder in a state that the lens
holder is located at an upper end position.
[0062] FIG. 39B is an enlarged perspective view showing a main part
of a moving mechanism for a lens holder in a state that the lens
holder is located at a lower end position.
[0063] FIG. 40 is a sectional perspective view of a part showing a
mode of supporting an upper end of a feed screw shown in FIG.
39A.
[0064] FIG. 41 is a functional block diagram showing an image
pick-up drive unit part.
[0065] FIG. 42 is an explanation diagram showing a situation of a
view field region of an objective lens group.
[0066] FIG. 43 is a flow chart showing a processing procedure of a
control program.
[0067] FIG. 44 is an explanation diagram showing a situation that
an image map is generated from a plurality of pick-up images.
[0068] FIG. 45 is an external appearance perspective view of
another example of an electronic endoscope used for describing an
embodiment of the present invention.
[0069] FIG. 46 is an exploded perspective view of an electronic
endoscope shown in FIG. 45.
[0070] FIG. 47 is a longitudinal sectional view of an electronic
endoscope shown in FIG. 45.
[0071] FIG. 48 is an enlarged perspective view of a part containing
an image pick-up drive unit part of an electronic endoscope shown
in FIG. 45.
[0072] FIG. 49 is a functional block diagram showing a control unit
mounted on an electronic endoscope shown in FIG. 45.
[0073] FIG. 50 is a flow chart showing a processing procedure of a
control program executed by a CPU shown in FIG. 49.
[0074] FIG. 51 is a longitudinal sectional view showing a state
that a lens holder has gone half around from a stare shown in FIG.
47.
[0075] FIG. 52 is a longitudinal sectional view showing a state
that a lens holder shown in FIG. 51 has been lowered to an image
pick-up completion position.
[0076] FIG. 53 is a diagram showing a situation of movement of a
field of view of image pick-up of an objective lens shown in FIG.
47.
[0077] FIG. 54 is a functional block diagram showing a control unit
serving as an alternative of that shown in FIG. 49.
[0078] FIG. 55 is an external appearance perspective view of
another example of an electronic endoscope used for describing an
embodiment of the present invention.
[0079] FIG. 56 is an exploded perspective view of an electronic
endoscope shown in FIG. 55.
[0080] FIG. 57 is a longitudinal sectional view of an electronic
endoscope shown in FIG. 55.
[0081] FIG. 58 is a plan view for describing a method of image
pick-up performed using an electronic endoscope shown in FIG.
55.
[0082] FIG. 59 is an external appearance perspective view of
another example of an electronic endoscope used for describing an
embodiment of the present invention.
[0083] FIG. 60 is an exploded perspective view of an electronic
endoscope shown in FIG. 59.
[0084] FIG. 61 is a schematic diagram showing a state that an
electronic endoscope shown in FIG. 59 is inserted into a hole
serving as a subject.
[0085] FIG. 62 is a functional block diagram showing a control unit
mounted on an electronic endoscope shown in FIG. 59.
[0086] FIG. 63 is an external appearance perspective view of
another example of an electronic endoscope used for describing an
embodiment of the present invention.
[0087] FIG. 64 is an external appearance perspective view of
another example of an electronic endoscope used for describing an
embodiment of the present invention.
[0088] FIG. 65 is an exploded perspective view of an electronic
endoscope shown in FIG. 64.
[0089] FIG. 66 is a longitudinal sectional view of an electronic
endoscope shown in FIG. 64.
[0090] FIG. 67 is a functional block diagram showing a control unit
mounted on an electronic endoscope shown in FIG. 64.
[0091] FIG. 68 is a longitudinal sectional view showing a state
that a lens holder has gone half around from a state shown in FIG.
66.
[0092] FIG. 69 is a longitudinal sectional view showing a state
that a lens holder shown in FIG. 66 has been lowered to an image
pick-up completion position.
[0093] FIG. 70 is an external appearance perspective view of
another example of an electronic endoscope used for describing an
embodiment of the present invention.
[0094] FIG. 71 is an exploded perspective view of an electronic
endoscope shown in FIG. 70.
[0095] FIG. 72 is a longitudinal sectional view of an electronic
endoscope shown in FIG. 70.
[0096] FIG. 73 is a functional block diagram showing a first
control unit mounted on an electronic endoscope shown in FIG.
70.
[0097] FIG. 74 is a functional block diagram showing a second
control unit mounted on an electronic endoscope shown in FIG.
70.
[0098] FIG. 75 is a flow chart showing a processing procedure of a
control program executed by a CPU shown in FIG. 74.
[0099] FIG. 76 is a longitudinal sectional view showing a state
that a lens holder has been lowered to an image pick-up completion
position.
[0100] FIG. 77 is a diagram showing a situation of movement of a
field of view of image pick-up of an objective lens shown in FIG.
72.
[0101] FIG. 78 is a longitudinal sectional view showing a state
that a lens holder has gone half around from a state shown in FIG.
72.
[0102] FIG. 79 is a longitudinal sectional view showing a state
that a lens holder has gone one around from a state shown in FIG.
72.
[0103] FIG. 80 is an external appearance perspective view of
another example of an electronic endoscope used for describing an
embodiment of the present invention.
[0104] FIG. 81 is a longitudinal sectional view of an electronic
endoscope shown in FIG. 80.
[0105] FIG. 82 is an exploded perspective view of an electronic
endoscope shown in FIG. 80.
[0106] FIG. 83 is an enlarged perspective view showing a main part
of an electronic endoscope shown in FIG. 80.
[0107] FIG. 84A is an enlarged perspective part view showing
operation of a moving lens frame provided with an objective lens in
a state that the moving lens frame is located at a raised
position.
[0108] FIG. 84B is an enlarged perspective part view showing
operation of a moving lens frame provided with an objective lens in
a state that the moving lens frame is located at a lowered
position.
[0109] FIG. 85A is a sectional view showing operation of a moving
lens frame provided with an objective lens in a state of having
gone half around from a revolution start position.
[0110] FIG. 85B is a sectional view showing operation of a moving
lens frame provided with an objective lens in a state of having
gone one around from a revolution start position.
[0111] FIG. 85C is a sectional view showing operation of a moving
lens frame provided with an objective lens in a state of being
located at a retarded position where revolution has been
completed.
[0112] FIG. 86 is a functional block diagram showing an image
pick-up drive unit part.
[0113] FIG. 87 is a flow chart showing a processing procedure of a
control program stored in a memory.
[0114] FIG. 88 is a diagram illustrating movement of a field of
view of image pick-up of an objective lens in a case that image
pick-up steps are executed repeatedly.
[0115] FIG. 89A is a schematic diagram showing a situation that the
inside of a subject is observed.
[0116] FIG. 89B is a schematic diagram showing a situation that the
inside of a subject is observed.
[0117] FIG. 89C is a schematic diagram showing a situation that the
inside of a subject is observed.
[0118] FIG. 90 is an external appearance perspective view of
another example of an electronic endoscope used for describing an
embodiment of the present invention.
[0119] FIG. 91 is an exploded perspective view of an electronic
endoscope shown in FIG. 90.
[0120] FIG. 92 is a longitudinal sectional view of an electronic
endoscope shown in FIG. 90.
[0121] FIG. 93 is a longitudinal sectional view showing a state
that a lens holder of an electronic endoscope shown in FIG. 90 has
gone half around from a state shown in FIG. 92.
[0122] FIG. 94 is a longitudinal sectional view showing a state
that a lens holder of an electronic endoscope shown in FIG. 90 has
gone to a most lowered position.
[0123] FIG. 95 is a functional block diagram showing an electronic
endoscope shown in FIG. 90.
[0124] FIG. 96 is a flow chart showing a processing procedure of a
control program executed by a control section of an electronic
endoscope shown in FIG. 90.
[0125] FIG. 97 is a schematic diagram showing a situation of
movement of a field of view of image pick-up of an electronic
endoscope shown in FIG. 90.
DESCRIPTION OF EMBODIMENTS
[0126] An electronic endoscope 1 shown in FIGS. 1 to 3 has an outer
shell constructed from a body part 11 and a transparent cover 13.
Then, its inside is provided with: a lens holder 19 that holds an
objective lens 17 for focusing object light through the transparent
cover 13; a driving section 21 for moving the lens holder 19 inside
the outer shell; and a solid-state imaging device 23 that receives
the object light acquired through the objective lens 17 and then
converts the light into an electric signal.
[0127] The body part 11 constituting a part of the outer shell is
fabricated from resin material or the like having light shielding
property and formed into a cylindrical shape whose one-end part 11a
is closed and whose the other end part 11c is open. The closed end
part (bottom part) 11a is provided with a tube-shaped battery
accommodating part 11b. The battery accommodating part 11b is
closed by a battery lid 27 after a power battery 25 is mounted.
[0128] That is, the electronic endoscope 1 is provided with the
power battery 25 in the inside, and hence does not require other
power supply from the outside. Thus, the electronic endoscope 1
need not be connected to a power supply cable, and hence permits
easy handling.
[0129] Here, in the example shown in the figure, in the bottom part
11a, two pipes 29 protrude outward from the outer shell. For
example, in a case that image data and an image map stored in a
memory 83 described later are to be transferred to an external
device, data transfer cables are inserted through and protected by
the pipes 29. The pipes 29 may be fabricated from soft material, or
alternatively may be fabricated from hard material so as to serve
as a grip used for inserting or extracting the electronic endoscope
1 into or from a hole serving as a subject, or for rotating the
electronic endoscope 1 during the use of the electronic endoscope
1.
[0130] The transparent cover 13 formed in a cylindrical shape whose
one-end part 13b is open. In the transparent cover 13, the open end
part 13b is aligned with the open end part 11c of the body part 11,
and then fixed to the body part 11 by appropriate means such as
bonding. Here, in the electronic endoscope 1, the shape of the body
part 11 and the transparent cover 13 serving as an outer shell need
not be a cylinder and may be a tube of another kind.
[0131] The other end part (tip part) 13a of the transparent cover
13 is formed in a smooth hemispherical shape for permitting easy
insertion into a hole serving as a subject. Then, the tip part 13a
and the open end part 13b are connected by a cylindrical part 13c
having the same diameter as the tip part 13a. The tip part 13a and
the cylindrical part 13c are formed in a smaller diameter than the
open end part 13b. As such, since the hemispherically formed tip
part 13a and the cylindrical part 13c are formed in a small
diameter, easy insertion into a relatively narrow hole serving as a
subject is achieved so that the range of application of the
electronic endoscope 1 is expanded.
[0132] The transparent cover 13 having the above-mentioned
configuration is fabricated from transparent resin material or the
like by integral molding or the like. Alternatively, the
hemispherically formed tip part 13a, the open end part 13b, and the
cylindrical part 13c may be fabricated as separate members, and
then may be joined to each other by appropriate means as such
bonding. In this case, at least the cylindrical part 13c serving as
a window part facing the inner peripheral surface of a hole serving
as a subject is formed transparent. Here, in the present invention,
the term "transparent" indicates that the material is transparent
to light at a particular wavelength sensitive to the imaging device
23. That is, the material need not be transparent to visible
light.
[0133] The lens holder 19 is formed from resin material or the like
and has: a disk-shaped flange 33 fit into the body part 11; and a
tube-shaped part 15 formed in a smaller diameter than the flange 33
and capable of entering the cylindrical part 13c of the transparent
cover 13. In the flange 33, its outer diameter is formed somewhat
smaller than the inner diameter of the body part 11. Thus, the
flange 33 moves in the inside of the body part 11 along the center
axis of the body part 11, that is, along the center axis of the
outer shell, smoothly without chattering. Further, in the
tube-shaped part 15, its outer diameter is formed somewhat smaller
than the inner diameter of the cylindrical part 13c of the
transparent cover 13. Thus, the tube-shaped part 15 moves in the
inside of the cylindrical part 13c along the center axis of the
outer shell smoothly without chattering.
[0134] In the flange 33 of the lens holder 19, engagement grooves
35 are formed in the outer peripheral surface. The inner peripheral
surface of the body past 11 is provided with ribs 31 extending
along the axis of the outer shell. Then, in the lens holder 19, the
engagement grooves 35 of the flange 33 are engaged with the ribs 31
of the body part 11. Thus, movement of the lens holder 19 is guided
in parallel to the center axis of the outer shell. That is,
revolution about a feed screw 67 described later is stopped. Here,
in the example shown in the figure, two engagement grooves 35 are
provided at intervals in the circumferential direction. However,
the number of such grooves need not be two.
[0135] In the tip part of the tube-shaped part 15, an objective
mirror 16 is accommodated. The objective mirror 16 has a shape
obtained by cutting a cylinder with an included plane intersecting
the center axis at 45 degrees. Then, the inclined surface is
fabricated in the form of a reflecting surface by formation of a
reflection film or the like.
[0136] Further, in the tube-shaped part 15, an image pick-up hole
is formed at a site radially facing the reflecting surface of the
objective mirror 16. Then, the objective lens 17 is mounted inside
the image pick-up hole. Then, object light is focused along the
cylindrical part 13c of the transparent cover 13 by the objective
lens 17 so as to travel to the objective mirror 16 in the form of a
parallel light beam. Then, the object light is reflected by the
reflecting surface of the objective mirror 16, and then travels
along the center axis of the tube-shaped part 15 in parallel to the
center axis of the outer shell with maintaining the form of a
parallel light beam.
[0137] In the inside of the body part 11, an image pick-up drive
unit part 37 is arranged at a position located on an extended line
of the center axis of the tube-shaped part 15 of the lens holder
19. The image pick-up drive unit part 37 is fixed inside the body
part 11 by a fixing member (not shown). The image pick-up drive
unit part 37 has three base plates 41, 42, and 43.
[0138] FIG. 4 shows the image pick-up drive unit past 37 in an
enlarged view. The solid-state imaging device 23 is provided on a
base plate 43 arranged most adjacent to the lens holder 19. The
imaging device 23 may be a CCD type imaging device, a CMOS type
imaging device, or the like. A memory 83 is mounted on a base plate
42 arranged under the base plate 43 (on the bottom part 11a side of
the body part 11). The memory 83 stores image data and the like
generated from image pick-up signals read out from the imaging
device 23. Further, a control unit 45 is mounted on a base plate 41
arranged under the base plate 42. The control unit 45 performs, for
example, read of image pick-up signals from the imaging device 23
and generation of image data on the basis of the read-out image
pick-up signals.
[0139] The imaging device 23 is arranged on the base plate 43 at a
position located on an extended line of the center axis of the
tube-shaped part 15 of the lens holder 19. Then, a focusing lens 51
is arranged at a position located above the imaging device 23 and
located on an extended line of the center axis of the tube-shaped
part 15. The focusing lens 51 is held by a focusing lens holder 49
provided on the base plate 43 in a manner of surrounding the
imaging device 23. The focusing lens 51 causes the object light L1
traveling in the form of a parallel light beam along the center
axis of the tube-shaped part 15 to be focused on the light
acceptance surface of the imaging device 23 so that image formation
is achieved. That is, the objective lens 17, the objective mirror
16, and the focusing lens 51 constitute an objective optical
system.
[0140] Further, a half mirror 53 is arranged on the optical path of
the object light between the objective mirror 16 accommodated in
the tube-shaped part 15 of the lens holder 19 and the focusing lens
51. The half mirror 53 allows transmission of at least a part of
the object light traveling from the objective mirror 16 toward the
focusing lens 51. Further, at a position located outside the
optical path of the object light between the objective mirror 16
and the focusing lens 51 and that faces the half mirror 53, a light
emitting diode (LED) 55 is provided that serves as a light source
for illuminating the image-taking object. Light for illumination L2
projected from the LED 55 is brought into the form of a parallel
light beam by an illumination lens 57 arranged between the LED 55
and the half mirror 53, and then enters the half mirror 53 so that
at least a part of the light is reflected toward the objective
mirror 16. Then, the light for illumination having entered the
objective mirror 16 is reflected toward the objective lens 17, and
then projected through the objective lens 17 and the transparent
cover 13 onto the image-taking object. Here, the half mirror 53,
the LED 55, and the illumination lens 57 are fixed inside the body
part 11 individually by appropriate fixing members.
[0141] Here, the movement of the lens holder 19 is guided along the
center axis of the outer shell by the above-mentioned engagement
between the engagement grooves 35 of the flange 33 and the ribs 31
of the body part 11. Then, the lens holder 19 whose movement is
guided along the center axis of the outer shell is allowed to move
such that the objective lens 17 held in the tube-shaped part 15
moves between height h1 shown in FIG. 5A and height hn shown in
FIG. 5B. In the following, the driving section 21 for moving the
lens holder 19 is described in detail with reference to FIGS. 3,
6A, 6B, and 7.
[0142] The inside of the body part 11 is provided with: a feed
screw 67 arranged in parallel to the center axis of the outer
shell; and a stepping motor 61 serving as a source of power for
driving and revolving the feed screw 67. A motor gear wheel 63 is
integrally attached to the shaft of the stepping motor 61, and a
gear wheel 69 is integrally attached to one-end part of the feed
screw 67. Then, between the motor gear wheel 63 and the gear wheel
69, an idle gear wheel 65 is provided such as to engage with these
gear wheels 63 and 69. The stepping motor 61 and the idle gear
wheel 65 are fixed inside the body part 11 by appropriate fixing
members. Further, as shown in FIG. 7, in the feed screw 67, its
one-end part is inserted into a shaft hole 13d formed in the flange
face of the open end part 13b of the transparent cover 13, while
the other end part is supported by a support arm 71 provided in the
side face of the focusing lens holder 49 of the image pick-up drive
unit part 37, so that the feed screw 67 is revolvable about the
center axis.
[0143] The revolution of the stepping motor 61 is transmitted
through the motor gear wheel 63, the idle gear wheel 65, and the
gear wheel 69 to the feed screw 67. Here, the idle gear wheel 65
has a larger number of gear teeth than the motor gear wheel 63.
Thus, the revolution of the stepping motor 61 is slowed down and
then transmitted to the idle gear wheel 65. Here, the employed
source of power for driving and revolving the feed screw 67 is not
limited to a stepping motor operated by pulse drive, and may be a
motor of a diverse kind such as a servo motor provided with an
encoder, or alternatively may be a power source of another
type.
[0144] On the other hand, in the flange 33 of the lens holder 19, a
through-hole 73 is formed that allows the stepping motor 61, the
motor gear wheel 63, the idle gear wheel 65, the feed screw 67, the
gear wheel 69, and the like to pass through. Then, in the lens
holder 19, a feed nut 75 screwed onto the feed screw 67 is attached
integrally by a nut holding piece 77. As described above, the lens
holder 19 is guided such that movement in the up and down
directions in the figure is permitted along the center axis of the
outer shell and that revolution movement about the feed screw 67 is
restricted. Thus, in association with revolution of the feed screw
67, the feed nut 75 screwed on the feed screw 67 and the lens
holder 19 that holds the feed nut 75 move along the feed screw 67,
that is, along the center axis of the outer shell.
[0145] For example, in a situation that the lens holder 19 is
located at a raised position shown in FIG. 6A, the stepping motor
61 is revolved in a predetermined direction so that the feed screw
67 is revolved via the motor gear wheel 63, the idle gear wheel 65,
and the gear wheel 69. In association with the revolution of the
feed screw 67, the feed nut 75 moves along the feed screw 67. By
virtue of this, the lens holder 19 formed integrally with the feed
nut 75 is lowered to the lowered position shown in FIG. 6B.
[0146] FIG. 8 is a functional block diagram showing the image
pick-up drive unit part 37. In the image pick-up drive unit part
37, the control unit 45 has: an LED drive circuit 85 for driving
the LED 55; an imaging device driver 87 for driving the imaging
device 23; a motor driver 89 for driving the stepping motor 61; a
pulse generator 91 for providing driving pulses to the motor driver
89; and a control section 81 for controlling the operation of the
LED drive circuit 85, the imaging device driver 87, and the pulse
generator 91. Further, the memory 83 stores a control program for
the control unit 45. Here, in addition to the storing of a control
program, the memory 83 stores image data and serves also as a work
memory. The control section 81 performs appropriate image
processing onto image pick-up signals read from the imaging device
23, so as to generate image data, and then stores the generated
image data into the memory 83. This configuration allows the
electronic endoscope 1 in a stand alone mode to acquire and save
images of image-taking objects. This provides excellence in easy
handling.
[0147] When the power switch 93 of the electronic endoscope 1 is
closed, electric power from the power battery 25 is supplied
through wiring (not shown) to the individual parts of the image
pick-up drive unit part 37, so that image pick-up is performed. For
example, the power switch 93 may be provided in the bottom part 11a
of the body part 11, and may be opened or closed by manual
operation. Alternatively, a switch terminal that follows magnetism
may be built in the body part 11. Then, from the outside of the
electronic endoscope 1, a magnet may be brought close or apart so
that the switch terminal may be opened or closed.
[0148] Next, the operation of the electronic endoscope 1 is
described below. When the power switch 93 is turned ON, electric
power is supplied from the power battery 25 to the individual
parts. Then, light for illumination is projected from the LED 55
through the objective lens 17 and the cylindrical part 13c of the
transparent cover 13 toward a side direction so that an
image-taking object is illuminated.
[0149] Reflected light from the image-taking object is acquired
into the electronic endoscope 1 through the cylindrical part 13c of
the transparent cover 13 and the objective lens 17, so that an
image is formed onto the light acceptance surface of the imaging
device 23 by the focusing lens 51. Then, charge accumulated in the
imaging device 23 as a result of photoelectric conversion is read
as an image pick-up signal by the control section (CPU) 81 of the
control unit 45. The control section 81 performs appropriate image
processing onto the read-out image pick-up signal so as to generate
image data, and then stores the generated image data into the
memory 83.
[0150] FIG. 9 is a flow chart showing the processing procedure of a
control program of the control unit 45 When the power switch 93 is
turned ON, fast, the stepping motor 61 is driven and revolved, so
that the lens holder 19 goes along the center axis of the outer
shell of the electronic endoscope 1 to a home position (step S1).
Here, the home position indicates, for example, the position shown
in FIG. 5A where the objective lens 17 is located on the tip side
of the electronic endoscope 1. However, the definition is not
limited to this. That is, the home position may be defined as the
opposite position where the objective lens 17 is located on the
pedestal side (the position shown in FIG. 5B).
[0151] After the lens holder 19 is set at the home position, image
pick-up processing is performed (step S2). The image pick-up
processing includes such processes that: the LED 55 is driven so as
to emit light for illumination; object light is acquired through
the objective lens 17 into the electronic endoscope 1 so that an
image is formed onto the light acceptance surface of the imaging
device 23; and on the basis of the image pick-up signal read from
the imaging device 23, image data is generated and then stored into
the memory 83.
[0152] Then, the stepping motor 61 is driven by a specified number
of pulses (step S3), so that the lens holder 19 is lowered by a
predetermined distance. Until the lens holder 19 reaches the most
lowered position (step S4), image pick-up processing is performed
at each destination of the movement (step S2). When the lens holder
19 reaches the most lowered position, the lowering operation of the
lens holder 19 and the image pick-up processing are terminated
(step S4). Here, in the electronic endoscope 1, the plural pieces
of image data stored in the memory 83 are combined into an image
map as shown in FIG. 10 (step S5).
[0153] In the image map shown in FIG. 10, the image data IMG(1)
indicates image data acquired in the first occasion of image
pick-up operation, which was taken over the view field region W1 in
a situation that the objective lens 17 was located at height h1
shown in FIG. 5A. Further, the image data IMG(2) indicates image
data acquired in the second occasion of image pick-up operation,
which was taken over the view field region W2 in a situation that
the objective lens 17 was lowered together with the lens holder 19
by a predetermined distance and thereby located at height h2.
[0154] As such, plural pieces of image data IMG(1) to IMG(n) each
obtained at each position of the movement of the lens holder 19 are
combined into a substantially single sheet of image data (image
map) by linking the data pieces sequentially in the order of image
pick-up in the moving direction of the lens holder 19. Here, for
example, the number of pulses provided to the stepping motor 61 at
step S3 may be adjusted appropriately, or alternatively the screw
pitch of the feed screw 67 may be adjusted appropriately, such that
a part of the view field region in the present occasion of image
pick-up processing should overlap with the view field region in the
preceding occasion of image pick-up processing. By virtue of this,
images of the image-taking object are acquired without a missing
part in the axial direction so that an image map without a gap is
obtained.
[0155] When the above-mentioned image map has been generated, the
image map is to be read from the memory 83 to the outside (see FIG.
8). This read may be performed by wireless, or alternatively
through a cable in a configuration that a data transfer cable is
inserted through the pipe 29 shown in FIG. 1 and connected to the
image pick-up drive unit part 37. Alternatively, the memory 83 may
be provided in a removable manner from the electronic endoscope 1.
Then, the removed memory 83 may be read by a personal computer
provided separately.
[0156] Further, the electronic endoscope 1 may transmit the image
data to an external monitor, so that the image may be observed on
line through the external monitor. In addition, operation
instructions may be inputted from the outside. In this case,
without performing image processing, the control section 81
transmits the image pick-up signal acquired from the imaging device
23, to an external video processor in an intact manner. Then, an
object image obtained by image processing by the video processor is
displayed on the external monitor. The communication between the
external video processor, the external monitor, and the control
section 81 may be of cable or wireless. In a case that the
communication is of cable, an external power source becomes
employable when a power source line is included in the wiring.
[0157] Further, as another example of the control program, a
control program may be employed that, in addition to the control
procedure shown in the flow chart of FIG. 9, allows the view field
region of the objective lens 17 to be moved to an arbitrary
position in accordance with an operation instruction from the
outside. In this case, selective image pick-up of a desired site is
achieved in accordance with the purpose of image pick-up, and hence
more detailed observation of the site is allowed.
[0158] According to the electronic endoscope 1 described above,
after being installed inside a hole, the objective lens 17 is moved
in the axial direction by the driving section 21. In association
with this, the field of view moves in the axial direction. This
permits accurate acquisition of an image over a large region of the
inner peripheral surface of the hole, without the necessity of a
skill in the operation.
[0159] An electronic endoscope 101 shown in FIGS. 11 to 13 has an
outer shell constructed from a body part 11 and a transparent cover
13. Then, its inside is provided with: a lens holder 119 that holds
an objective lens group 117 for focusing object light through the
transparent cover 13; a driving section 21 for moving the lens
holder 119 inside the outer shell; and a solid-state imaging device
23 that receives the object light acquired through the objective
lens group 117 and then converts the light into an electric signal.
Here, like members to those of the electronic endoscope 1 described
above are designated by like numerals, and functionally common
members are designated by appropriately corresponding numerals.
Then, their description is omitted or simplifier.
[0160] The lens holder 119 is formed from resin material or the
like and has: a disk-shaped flange 33 fit into the body part 11;
and a tube-shaped part 115 formed in a smaller diameter than the
flange 33 and capable of entering the cylindrical part 13c of the
transparent cover 13. The flange 33 moves in the inside of the body
part 11 along the center axis of the body part 11, that is, along
the center axis of the outer shell, smoothly without chattering.
Further, the tube-shaped part 115 moves in the inside of the
cylindrical part 13c along the center axis of the outer shell
smoothly without chattering.
[0161] In the electronic endoscope 101, the objective lens group
117 held by the lens holder 119 includes a wide-angle lens and
constructed from a wide-angle lens 117A and a lens 117B.
Preferably, the wide-angle lens 117A is composed of a fish-eye
lens. In this case, a circular fish-eye lens is suitable for
observation in the entire circumferential directions where the
inclination angle (angle relative to the lens optical axis) is
large. That is, the wide-angle lens of the present invention is a
wide-angle lens having an observational field of view that permits
observation in the entire side circumferential directions around
the optical axis (the center axis of the tube-shaped part 115) of
the objective lens group 117. Here, in addition to this
configuration, the wide-angle lens 117A may be composed of a
diagonal fish-eye lens, a common wide-angle lens, or the like. The
objective lens group 117 is attached to the opening part on the tip
side of the tube-shaped part 115 in a state that its lens optical
axis agrees with the center axis of the tube-shaped part 115 of the
lens holder 119.
[0162] Object light is focused along the cylindrical part 13c of
the transparent cover 13 into the form of a parallel light beam by
the objective lens group 117, and then travels along the center
axis of the tube-shaped part 115 in parallel to the center axis of
the outer shell. In the inside of the body part 11, the image
pick-up drive unit part 37 is arranged at a position located on an
extended line of the center axis of the tube-shaped part 115 of the
lens holder 119. The image pick-up drive unit part 37 and the
driving section 21 for moving the lens holder 119 are the same as
those of the electronic endoscope 1 described above. Thus, their
description is omitted.
[0163] Next, the operation of the electronic endoscope 101 is
described below. With reference to FIG. 8, the power switch 93 is
turned ON so that electric power is supplied from the power battery
25 to the individual parts. Then, light for illumination is
projected from the LED 55 through the objective lens group 117 and
the cylindrical part 13c of the transparent cover 13 toward a side
direction so that an image-taking object is illuminated. Reflected
light from the image-taking object is acquired into the electronic
endoscope 1 through the cylindrical part 13c of the transparent
cover 13 and the objective lens group 117, so that an image is
formed onto the light acceptance surface of the imaging device 23
by the focusing lens 51.
[0164] FIG. 14 shows the situation of the view field region W
formed by the objective lens group 117. The light for illumination
emitted from the wide-angle lens 117A is projected onto the region
indicated as the view field region W. Among the reflected light
from the image-taking object illuminated by the light for
illumination, the part of light belonging to the view field region
W is used in image formation and then acquired by the imaging
device 23. Here, symbol M indicates a mask for limiting the view
field region into W.
[0165] Then, charge accumulated in the imaging device 23 as a
result of photoelectric conversion is read as an image pick-up
signal by the control section (CPU) 81 of the control unit 45. The
control section 81 performs appropriate image processing onto the
read-out image pick-up signal so as to generate image data, and
then stores the generated image data into the memory 83.
[0166] The control program for the electronic endoscope 101 is the
same as that for the electronic endoscope 1 described above. Thus,
with reference to FIG. 9, when the power switch 93 is turned ON,
first, the stepping motor 61 is driven and revolved so that the
lens holder 119 goes along the center axis of the outer shell of
the electronic endoscope 1 to a home position (step S1). After the
lens holder 119 is set at the home position, image pick-up
processing is performed (step S2).
[0167] Then, the stepping motor 61 is driven by a specified number
of pulses (step S3), so that the lens holder 119 is lowered by a
predetermined distance. Here, the predetermined distance indicates
a step distance by which the lens holder 119 is to be moved
stepwise in order that the view field region W shown in FIG. 14
should cover stepwise the movable region of the lens holder 119.
For example, the predetermined distance may be the height La of a
part contained in the view field region W in the cylindrical part
13c of the transparent cover 13.
[0168] Until the lens holder 119 reaches the most lowered position
(step S4), image pick-up processing is performed at each
destination of the movement (step S2). When the lens holder 119
reaches the most lowered position, the lowering operation of the
lens holder 119 and the image pick-up processing are terminated
(step S4). Here, also in the electronic endoscope 101, the plural
pieces of image data stored in the memory 83 are combined into an
image map as shown in FIG. 15 (step S5).
[0169] In the image map shown in FIG. 15, the image data IMG(1)
indicates image data that was acquired in the first occasion of
image pick-up operation, which was taken over the view field region
W1 in the entire directions (circumferential angle from 0 degree to
360 degrees) in a situation that the objective lens group 117 is at
height h1. Further, the image data IMG(2) indicates image data
acquired in the second occasion of image pick-up operation, which
was taken over the view field region W2 in the entire directions in
a situation that the objective lens group 117 was lowered together
with the lens holder 119 by a predetermined distance and thereby
located at height h2. As such, plural pieces of image data IMG(1)
to IMG(n) each obtained at each position of the movement of the
lens holder 119 are combined into a substantially single sheet of
image data (image map) by linking the data pieces sequentially in
the order of image pick-up in the moving direction of the lens
holder 119.
[0170] According to the electronic endoscope 101, the objective
lens group 117 includes the wide-angle lens 117A. This permits
image pick-up over a larger region in the circumferential direction
in comparison with the case of the electronic endoscope 1. In
particular, when a fish-eye lens is employed, image pick-up is
achieved in the entire directions.
[0171] An electronic endoscope 201 shown in FIGS. 16 to 18 has an
outer shell constructed from a body part 11 and a transparent cover
13. Then, its inside is provided with: a lens holder 219 that holds
an objective lens 17 for focusing object light through the
transparent cover 13; a driving section 221 for moving the lens
holder 219 in the axial direction inside the outer shell; and a
solid-state imaging device 23 that receives the object light
acquired through the objective lens 17 and then converts the light
into an electric signal. Here, like members to those of the
electronic endoscope 1 described above are designated by like
numerals, and functionally common members are designated by
appropriately corresponding numerals. Then, their description is
omitted or simplified.
[0172] The lens holder 219 is formed from resin material or the
like and has: a disk-shaped flange 233 fit into the body part 11;
and a tube-shaped part 215 formed in a smaller diameter than the
flange 233 and capable of entering the cylindrical part 13c of the
transparent cover 13. The flange 233 moves in the inside of the
body part 11 along the center axis of the body part 11, that is,
along the center axis of the outer shell, smoothly without
chattering. Further, the tube-shaped part 215 moves in the inside
of the cylindrical part 13c along the center axis of the outer
shell smoothly without chattering.
[0173] The tube-shaped part 215 and the flange 233 are formed
separately from each other. Then, the tube-shaped part 215 is
attached to the flange 233. In the center part of the flange 233, a
hollow cylindrical shaft 236 is provided in a protruding manner.
The tube-shaped part 215 is attached to the flange 233 in a state
that the pedestal part of the tube-shaped part 215 is fit outside
the shaft 236. Thus, the tube-shaped part 215 is supported in a
revolvable manner about the shaft 236.
[0174] In the flange 233 of the lens holder 219, engagement grooves
235 are formed in the outer peripheral surface. The inner
peripheral surface of the body part 11 is provided with ribs 31
extending along the axis of the outer shell. Then, in the lens
holder 219, the engagement grooves 235 of the flange 233 are
engaged with the ribs 31 of the body part 11. Thus, movement of the
lens holder 219 is guided in parallel to the center axis of the
outer shell. That is, revolution about a feed screw 67 described
later is stopped.
[0175] On the tip side of the tube-shaped part 215, an objective
mirror 16 is accommodated. Further, in the tube-shaped part 215, an
image pick-up hole is formed at a site radially facing the
reflecting surface of the objective mirror 16. Then, the objective
lens 17 is mounted inside the image pick-up hole. Then, object
light is focused along the cylindrical part 13c of the transparent
cover 13 by the objective lens 17 so as to travel to the objective
mirror 16 in the form of a parallel light beam. Then, the object
light is reflected by the reflecting surface of the objective
mirror 16, and then travels along the center axis of the
tube-shaped part 215 in parallel to the center axis of the outer
shell with maintaining the form of a parallel light beam.
[0176] In the inside of the body part 11, an image pick-up drive
unit part 37 is arranged at a position located on an extended line
of the center axis of the tube-shaped part 15 of the lens holder
19. The image pick-up drive unit part 37 is the same as that of the
electronic endoscope 1 described above. Thus, description is
omitted.
[0177] Here, the movement of the lens holder 219 is guided along
the center axis of the outer shell by the above-mentioned
engagement between the engagement grooves 235 of the flange 233 and
the ribs 31 of the body part 11. The driving section 221 for moving
the lens holder 219 along the center axis of the outer shell is
described below in detail with reference to FIGS. 18 and 19.
[0178] The inside of the body part 11 is provided with: a feed
screw 67 arranged in parallel to the center axis of the outer
shell; and a stepping motor 61 serving as a source of power for
driving and revolving the feed screw 67. A motor gear wheel 63 is
attached to the shaft of the stepping motor 61, and a gear wheel 69
is attached to one-end part of the feed screw 67. Then, between the
motor gear wheel 63 and the gear wheel 69, an idle gear wheel 65 is
provided such as to engage with these gear wheels 63 and 69. The
revolution of the stepping motor 61 is transmitted through the
motor gear wheel 63, the idle gear wheel 65, and the gear wheel 69
to the feed screw 67.
[0179] On the other hand, in the flange 233 of the lens holder 219,
a through-hole 73 is formed that allows the stepping motor 61, the
motor gear wheel 63, the idle gear wheel 65, the feed screw 67, the
gear wheel 69, and the bike to pass through. Then, in the periphery
of the through-hole 73 of the flange 233, a feed nut 75 screwed
onto the feed screw 67 is attached by a nut holding piece 77. As
described above, in the lens holder 219, movement is guided along
the center axis of the outer shell, that is, revolution about the
feed screw 67 is stopped. Thus, in association with revolution of
the feed screw 67, the feed nut 75 screwed on the feed screw 67 and
the lens holder 219 that holds the feed nut 75 move along the feed
screw 67, that is, along the center axis of the outer shell.
[0180] Further, in the driving section 221, a shaft 268 arranged in
parallel to the feed screw 67 is provided. In the shaft 268, an
external-tooth gear is formed in the outer peripheral surface and
engages with the gear wheel 69 fixed to the feed screw 67, and
hence revolves about the center axis together with the feed screw
67. Then, in the pedestal part of the tube-shaped part 215, a gear
wheel 270 engaging with the shaft 268 is fixed by appropriateness
means such as press fit and bonding. In accordance with the
revolution of the feed screw 67, the gear wheel 270 of the
tube-shaped part 215 moves in the axial direction together with the
lens holder 219 and maintains the engagement with the shaft 268.
Then, the tube-shaped part 215 is driven and revolved through the
shaft 268 and the gear wheel 270.
[0181] For example, in a situation that the lens holder 219 is
located at a raised position shown in FIG. 20, the stepping motor
61 is revolved in a predetermined direction so that the feed screw
67 is revolved via the motor gear wheel 63, the idle gear wheel 65,
and the gear wheel 69. In association with the revolution of the
feed screw 67, the feed nut 75 moves along the feed screw 67. As a
result, the lens holder 219 is lowered.
[0182] Then, as shown in FIG. 21, during the course that the lens
holder 219 is lowered by .DELTA.h, the tube-shaped part 215 is
revolved via the shaft 268 and the gear wheel 270 by a
predetermined angle. In accordance with the revolution of the
tube-shaped part 215, the objective lens 17 is also revolved so
that the field of view of image pick-up moves in the
circumferential direction.
[0183] Next, the operation of the electronic endoscope 201 is
described below. With reference to FIG. 8, the power switch 93 is
turned ON so that electric power is supplied from the power battery
25 to the individual parts. Then, light for illumination is
projected from the LED 55 through the objective lens 17 and the
cylindrical part 13c of the transparent cover 13 toward a side
direction so that an image-taking object is illuminated. Reflected
light from the image-taking object is acquired into the electronic
endoscope 201 through the cylindrical part 13c of the transparent
cover 13 and the objective lens 17, so that an image is formed onto
the light acceptance surface of the imaging device 23 by the
focusing lens 51. Then, charge accumulated in the imaging device 23
as a result of photoelectric conversion is read as an image pick-up
signal by the control section (CPU) 81 of the control unit 45. The
control section 81 performs appropriate image processing onto the
read-out image pick-up signal so as to generate image data and then
stores the generated image data into the memory 83.
[0184] The control program for the electronic endoscope 201 is the
same as that for the electronic endoscope 1 described above. Thus,
with reference to FIG. 9, when the power switch 93 is turned ON,
first, the stepping motor 61 is driven and revolved so that the
lens holder 219 goes along the center axis of the outer shell of
the electronic endoscope 201 to a home position (step S1). After
the lens holder 219 is set at the home position, image pick-up
processing is performed (step S2). Then, the stepping motor 61 is
driven by a specified number of pulses (step S3), so that the lens
holder 219 is lowered by a predetermined distance. Until the lens
holder 219 reaches the most lowered position (step S4), image
pick-up processing is performed at each destination of the movement
(step S2). When the lens holder 219 reaches the most lowered
position, the lowering operation of the lens holder 219 and the
image pick-up processing are terminated (step S4).
[0185] FIG. 22 is a diagram illustrating the movement of the field
of view of image pick-up achieved when the above-mentioned steps S2
to S4 are executed repeatedly. In the first occasion of image
pick-up processing performed at the home position, image pick-up is
performed in the field of view "No. 001", and hence image data of
the field of view "No. 001" is generated from the image pick-up
signal read from the imaging device 23.
[0186] Once the image pick-up processing in the field of view "No.
001" is completed, the stepping motor 61 is driven at step S3 by a
specified number of pulses so that the lens holder 219 is lowered
and the tube-shaped part 215 is revolved. As a result, the next
field of view "No. 002" is set up. Then, image pick-up is performed
in the field of view "No. 002", and hence image data of the field
of view "No. 002" is generated from the image pick-up signal read
from the imaging device 23.
[0187] After that, image pick-up processing is repeated with moving
the field of view like "No. 003".fwdarw."No. 004".fwdarw."No. 005"
. . . . When the tube-shaped part 215 has gone one around from the
home position, the field of view of image pick-up is located at
"No. 011" in FIG. 22. In case of having gone around twice, the
field of view of image pick-up is located at "No. 021" in FIG.
22.
[0188] Here, for example, the number of pulses provided to the
stepping motor 61 at step S3 may be adjusted appropriately, or
alternatively the screw pitch of the feed screw 67 may be adjusted
appropriately, so that circumferentially adjacent fields of view of
image pick-up may be positioned such that their left and right edge
parts should be in contact with each other or overlapping somewhat
with each other and axially adjacent fields of view of image
pick-up may be positioned such that their upper and lower edge
parts should be in contact with each other or overlapping somewhat
with each other. According to this configuration, image taking of
an object is achieved without a missing part in the axial and the
circumferential directions. Thus, an image map without a gap is
obtained.
[0189] According to the electronic endoscope 201, the objective
lens 17 is moved in the axial and the circumferential directions by
the driving section 221. Then, in accordance with this, the field
of view moves in the axial and the circumferential directions. By
virtue of this, image pick-up is achieved in the entire directions
without the necessity of a fish-eye lens like in the electronic
endoscope 101.
[0190] An electronic endoscope 301 shown in FIGS. 23 to 25 has an
outer shell constructed from a body part 11 and a transparent cover
313. Then, its inside is provided with: a lens holder 319 that
holds an objective lens 17 for focusing object light through the
transparent cover 313; a driving section 321 for moving the lens
holder 319 inside the outer shell; and a solid-state imaging device
23 that receives the object light acquired through the objective
lens 17 and then converts the light into an electric signal. Here,
like members to those of the electronic endoscope 1 described above
are designated by like numerals, and functionally common members
are designated by appropriately corresponding numerals. Then, their
description is omitted or simplified.
[0191] The transparent cover 313 formed in a cylindrical shape
whose one-end part 313b is open. The transparent cover 313 is fixed
to the body part 11 in a state that the open end part 313b is
aligned with the open end part 11c of the body part 11. The other
end part (tip part) 313a of the transparent cover 313 is formed in
a smooth hemispherical shape for permitting easy insertion into a
hole serving as a subject. Then, the tip part 313a and the open end
part 313b are connected by a cylindrical part 313c having the same
diameter as the tip part 313a. In the electronic endoscope 301, the
tip part 313a and the cylindrical part 313c are formed in the same
diameter as the open end part 313b.
[0192] The transparent cover 313 having the above-mentioned
configuration may be fabricated, for example, by integral molding
by using transparent resin material or the like. However, it is
sufficient that at least the cylindrical part 313c serving as a
window part facing the inner peripheral surface of a hole serving
as a subject is formed transparent.
[0193] The lens holder 319 is formed from resin material or the
like and has: an objective lens mount part 314 formed in an
approximately disk shape; and a tube-shaped part 315 formed in a
cylindrical shape having a smaller diameter than the objective lens
mount part 314. The tube-shaped part 315 is arranged such that its
center axis agrees with the center axis of the transparent cover
313, that is, the center axis of the outer shell. The objective
lens mount part 314 is provided at the tip of the tube-shaped part
315 coaxially to the tube-shaped part 315.
[0194] In the objective lens mount part 314, its outer diameter is
formed somewhat smaller than the inner diameter of the cylindrical
part 313c of the transparent cover 313. Thus, the objective lens
mount part 314 is allowed to move in the inside of the transparent
cover 313 smoothly without chattering along the center axis of the
transparent cover 313, that is, the center axis of the outer
shell.
[0195] In the outer peripheral surface of the tube-shaped part 315,
an external-tooth gear 315a is formed. The gear teeth of the
external-tooth gear 315a extend in parallel to the center axis of
the tube-shaped part 315, and are formed at equal intervals in the
circumferential direction. Further, in the inner peripheral surface
of the tube-shaped part 315, a female screw 315b is formed that is
screwed into a thread groove formed in the outer peripheral surface
of the feed screw 367 described later.
[0196] In the objective lens mount part 314, a cylindrical hole
314a is formed that is continuous to the tip opening of the
tube-shaped part 315 and extends in the axial direction of the
tube-shaped part 315. Then, an objective mirror 16 is accommodated
in the cylindrical hole 314a. Further, in the objective lens mount
part 314, an image pick-up hole 314b is formed that extends in a
radial direction and whose one end opens in the outer peripheral
surface and whose the other end faces the reflecting surface of the
objective mirror 16 in a radial direction and communicates with the
cylindrical hole 314a. Then, an objective lens 17 is mounted in the
opening part on the outer periphery side of the image pick-up hole
314b.
[0197] Object light is focused along the cylindrical part 313c of
the transparent cover 313 by the objective lens 17 so as to travel
to the objective mirror 16 in the form of a parallel light beam.
Then, the object light is reflected by the reflecting surface of
the objective mirror 16, and then travels along the center axis of
the tube-shaped part 315, that is, along the center axis of the
outer shell, with maintaining the form of a parallel light
beam.
[0198] In the inside of the body part 11, an image pick-up drive
unit part 37 is arranged at a position located on an extended line
of the center axis of the tube-shaped part 315 of the lens holder
319. The image pick-up drive unit part 37 is the same as that of
the electronic endoscope 1 described above. Thus, description is
omitted.
[0199] On the base plate 43 of the image pick-up drive unit part
37, a feed screw 367 is attached coaxially to the tube-shaped part
315 of the lens holder 319. The feed screw 367 formed in a
cylindrical shape, and accommodates the focusing lens holder 49 in
the inside. Further; the feed screw 367 has a thread groove formed
in the outer peripheral surface. Then, in such a manner that this
thread groove is screwed into the female screw 315b of the inner
peripheral surface of the tube-shaped part 315, the feed screw 367
is inserted into the tube-shaped part 315. The object light
traveling along the center axis of the tube-shaped part 315 goes
into the feed screw 367, then enters the focusing lens 51 held by
the focusing lens holder 49, and then is focused onto the light
acceptance surface of the imaging device 23 by the focusing lens 51
so that an image is formed.
[0200] Here, the LED 55 serving as a light source for illuminating
the image-taking object is arranged outside the feed screw 367. The
half mirror 53 for reflecting the light for illumination from the
LED 55 toward the objective mirror 16 is arranged inside the feed
screw 367 and is located in the middle of the optical path of the
object light. The tube wall of the feed screw 367, which intervenes
between the LED 55 and the half mirror 53, is provided with an
attachment hole. Then, the illumination lens 57 is attached in the
attachment hole. The light for illumination from the LED 55 is
brought into the form of a parallel light beam by the illumination
lens 57, and then enters the half mirror 53. Then, at least a part
of the light is reflected toward the objective mirror 16. Then, the
light for illumination having entered the objective mirror 16 is
reflected toward the objective lens 17, and then projected through
the objective lens 17 and the transparent cover 313 onto the
image-taking object.
[0201] Here, in the lens holder 319 where its tube-shaped part 315
is screwed into the feed screw 367, movement is guided along the
feed screw 367, that is, along the center axis of the outer shell.
The driving section 321 for moving the lens holder 319 along the
center axis of the outer shell is described below in detail with
reference to FIG. 24.
[0202] A stepping motor 61 is fixed inside the body part 11.
Further, an idle gear wheel 65 is provided that is located between
and engaging with both of the motor gear wheel 63 of the stepping
motor 61 and the external-tooth gear 315a formed in the tube-shaped
part 315 of the lens holder 319. The revolution of the stepping
motor 61 is transmitted through the motor gear wheel 63 and the
idle gear wheel 65 to the lens holder 319.
[0203] In the lens holder 319, the tube-shaped part 315 is fit
outside the feed screw 367. Thus, when revolution of the stepping
motor 61 is transmitted, the lens holder 319 revolves about the
feed screw 367. At the same time, the tube-shaped part 315 is
screwed onto the feed screw 367 by means of the female screw 315b
formed in the inner peripheral surface. Thus, in association with
revolution about the feed screw 367, the lens holder 319 moves
along the feed screw 367.
[0204] For example, in a situation that the lens holder 319 is
located at a raised position shown in FIG. 26, the stepping motor
61 is revolved in a predetermined direction so that the lens holder
319 is revolved via the motor gear wheel 63 and the idle gear wheel
65. As a result, as shown in FIG. 27, the lens holder 319 revolves
about the feed screw 367 so as to go lower by .DELTA.h along the
feed screw 367. In accordance with the revolution of the lens
holder 319, the objective lens 17 is also revolved so that the
field of view of image pick-up moves in the circumferential
direction.
[0205] Next, the operation of the electronic endoscope 301 is
described below.
[0206] With reference to FIG. 8, the power switch 93 is turned ON
so that electric power is supplied from the power battery 25 to the
individual parts. Then, light for illumination is projected from
the LED 55 through the objective lens 17 and the cylindrical part
313c of the transparent cover 313 toward a side direction so that
an image-taking object is dominated. Reflected light from the
image-taking object is acquired into the electronic endoscope 301
through the cylindrical part 313c of the transparent cover 313 and
the objective lens 17, so that an image is formed onto the light
acceptance surface of the imaging device 23 by the focusing lens
51. Then, charge accumulated in the imaging device 23 as a result
of photoelectric conversion is read as an image pick-up signal by
the control section (CPU) 81 of the control unit 45. The control
section 81 performs appropriate image processing onto the read-out
image pick-up signal so as to generate image data, and then stores
the generated image data into the memory 81
[0207] The control program for the electronic endoscope 301 is the
same as that for the electronic endoscope 1 described above. Thus,
with reference to FIG. 9, when the power switch 93 is turned ON,
first, the stepping motor 61 is driven and revolved so that the
lens holder 319 goes along the center axis of the outer shell of
the electronic endoscope 301 to a home position (step S1). After
the lens holder 319 is set at the home position, image pick-up
processing is performed (step S2). Then, the stepping motor 61 is
driven by a specified number of pulses (step S3), so that the lens
holder 319 is lowered by a predetermined distance. Until the lens
holder 319 reaches the most lowered position (step S4), image
pick-up processing is performed at each destination of the movement
(step S2). When the lens holder 319 reaches the most lowered
position, the lowering operation of the lens holder 319 and the
image pick-up processing are terminated (step S4).
[0208] FIG. 28 is a diagram illustrating the movement of the field
of view of image pick-up achieved when the above-mentioned steps S2
to S4 are executed repeatedly. In the first occasion of image
pick-up processing performed at the home position, image pick-up is
performed in the field of view "No. 001", and hence image data of
the field of view "No. 001" is generated from the image pick-up
signal read from the imaging device 23.
[0209] Once the image pick-up processing in the field of view "No.
001" is completed, the stepping motor 61 is driven at step S3 by a
specified number of pulses so that the lens holder 319 is lowered
and revolved. As a result, the next field of view "No. 002" is set
up. Then, image pick-up is performed in the field of view "No.
002", and hence image data of the field of view "No. 002" is
generated from the image pick-up signal read from the imaging
device 23.
[0210] After that, image pick-up processing is repeated with moving
the field of view like "No. 003".fwdarw."No. 004".fwdarw."No. 005"
. . . . When the lens holder 319 has gone one around from the home
position, the field of view of image pick-up is located at "No.
011" in FIG. 28. In case of having gone around twice, the field of
view of image pick-up is located at "No. 021" in FIG. 28.
[0211] Here, for example, the number of pulses provided to the
stepping motor 61 at step S3 may be adjusted appropriately, or
alternatively the screw pitch of the feed screw 367 may be adjusted
appropriately, so that circumferentially adjacent fields of view of
image pick-up may be positioned such that their left and right edge
parts should be in contact with each other or overlapping somewhat
with each other and axially adjacent fields of view of image
pick-up may be positioned such that their upper and lower edge
parts should be in contact with each other or overlapping somewhat
with each other. According to this configuration, image taking of
an object is achieved without a missing part in the axial and the
circumferential directions. Thus, an image map without a gap is
obtained.
[0212] According to the electronic endoscope 301, the objective
lens 17 is moved in the axial and the circumferential directions by
the driving section 321. Then, in accordance with this, the field
of view moves in the axial and the circumferential directions. By
virtue of this, image pick-up is achieved in the entire directions
without the necessity of a fish-eye lens like in the electronic
endoscope 101 described above.
[0213] An electronic endoscope 401 shown in FIGS. 29 to 31 has an
outer shell constructed from a body part 11 and a transparent cover
313. Then, its inside is provided with: a lens holder 419 that
holds an objective lens 17 for focusing object light through the
transparent cover 313; a driving section 421 for moving the lens
holder 419 inside the outer shell; and a solid-state imaging device
23 that receives the object light acquired through the objective
lens 17 and then converts the light into an electric signal. Here,
like members to those of the electronic endoscope 1 or 301
described above are designated by like numerals, and functionally
common members are designated by appropriately corresponding
numerals. Then, their description is omitted or simplified.
[0214] The lens holder 419 is formed from resin material or the
like and has: an objective lens mount part 414 formed in an
approximately disk shape; and a tube-shaped part 415 formed in a
cylindrical shape having the same diameter as the objective lens
mount part 414. The tube-shaped part 415 is arranged such that its
center axis agrees with the center axis of the transparent cover
313, that is, the center axis of the outer shell. The objective
lens mount part 414 is provided at the tip of the tube-shaped part
415 coaxially to the tube-shaped part 415.
[0215] In the objective lens mount part 414 and the tube-shaped
part 415, their outer diameter is formed somewhat smaller than the
inner diameter of the cylindrical part 313c of the transparent
cover 313. Thus, the objective lens mount part 414 is allowed to
move in the inside of the transparent cover 313 smoothly without
chattering along the center axis of the transparent cover 313, that
is, the center axis of the outer shell.
[0216] In the inner peripheral surface of the tube-shaped part 415,
an internal-tooth gear 415a is formed. The gear teeth of the
internal-tooth gear 415a extend in parallel to the center axis of
the tube-shaped part 415, and are formed at equal intervals in the
circumferential direction. Further, in the outer peripheral surface
of the tube-shaped part 415, a male screw 415b is formed that is
screwed into the thread groove formed in the inner peripheral
surface of the body part 11.
[0217] In the objective lens mount part 414, a cylindrical hole
414a is formed that is continuous to the tip opening of the
tube-shaped part 415 and extends in the axial direction of the
tube-shaped part 415. Then, an objective mirror 16 is accommodated
in the cylindrical hole 414a. Further, in the objective lens mount
part 414, an image pick-up hole 414b is formed that extends in a
radial direction and whose one end opens in the outer peripheral
surface and whose the other end faces the reflecting surface of the
objective mirror 16 in a radial direction and communicates with the
cylindrical hole 414a. Then, an objective lens 17 is mounted in the
opening part on the outer periphery side of the image pick-up hole
414b.
[0218] Object light is focused along the cylindrical part 313c of
the transparent cover 313 by the objective lens 17 so as to travel
to the objective mirror 16 in the form of a parallel light beam.
Then, the object light is reflected by the reflecting surface of
the objective mirror 16, and then travels along the center axis of
the tube-shaped part 415 in parallel to the center axis of the
outer shell, with maintaining the form of a parallel light
beam.
[0219] In the inside of the body part 11, an image pick-up drive
unit part 37 is arranged at a position located on an extended line
of the center axis of the tube-shaped part 415 of the lens holder
419. The image pick-up drive unit part 37 is the same as that of
the electronic endoscope 1 described above. Thus, description is
omitted.
[0220] Here, in the lens holder 419 whose tube-shaped part 415 is
screwed into the thread groove formed in the inner peripheral
surface of the body part 11, movement is guided along the center
axis of the body part 11, that is, along the center axis of the
outer shell. The driving section 421 for moving the lens holder 419
along the center axis of the outer shell is described below in
detail with reference to FIG. 30.
[0221] A stepping motor 61 is fixed inside the body part 11.
Further, an idle gear wheel 65 is provided that is located between
and engaging with both of the motor gear wheel 63 of the stepping
motor 61 and the internal-tooth gear 415a formed in the tube-shaped
part 415 of the lens holder 419. The revolution of the stepping
motor 61 is transmitted through the motor gear wheel 63 and the
idle gear wheel 65 to the lens holder 419.
[0222] In the lens holder 419, the tube-shaped part 415 is fit into
the body part 11. Thus, when revolution of the stepping motor 61 is
transmitted, the lens holder 419 revolves about the center axis of
the body part 11. At the same time, the tube-shaped part 415 is
screwed into the thread groove formed in the inner peripheral
surface of the body part 11 by means of the male screw 415b formed
in the outer peripheral surface. Thus, in association with
revolution about the center axis of the body part 11, the lens
holder 419 moves along the center axis of the body part 11.
[0223] For example, in a situation that the lens holder 419 is
located at a raised position shown in FIG. 32, the stepping motor
61 is revolved in a predetermined direction so that the lens holder
419 is revolved via the motor gear wheel 63 and the idle gear wheel
65. As a result, as shown in FIG. 33, the lens holder 419 revolves
about the center axis of the body part 11 so as to go lower by
.DELTA.h along the center axis of the body part 11. In accordance
with the revolution of the lens holder 419, the objective lens 17
is also revolved so that the field of view of image pick-up moves
in the circumferential direction.
[0224] The operation of the electronic endoscope 401 is similar to
that of the electronic endoscope 301 described above. That is, the
driving section 421 causes the lens holder 419 that holds the
objective lens 17 to move in the axial and the circumferential
directions sequentially. Then, in the course of this motion, image
pick-up is performed in the entire directions.
[0225] According to the electronic endoscope 401, in the guiding of
the movement of the lens holder 419, the inner peripheral surface
of the body part 11 is used in place of the feed screw 367 of the
electronic endoscope 301 described above. This reduces the number
of components and, at the same time, permits such a configuration
that the image pick-up drive unit part 37 and the hie are
accommodated inside the tube-shaped part 415 guided by the inner
peripheral surface of the body part 11. Accordingly, efficient
space utilization is achieved and size reduction of the electronic
endoscope is realized.
[0226] As described above with reference to the electronic
endoscopes 1, 101, 201, 301, and 401 serving as examples, the
present specification has disclosed an electronic endoscope
characterized in that an outer shell that is formed in a tube shape
and whose peripheral wall is provided with a transparent window
part extending in an axial direction; a solid-state imaging device
that is provided inside the outer shell; an objective optical
system that includes an objective lens for focusing object light
through the window part and that forms an image onto the
solid-state imaging device; and a drive mechanism that causes at
least the objective lens in the objective optical system to move
along an axis of the outer shell.
[0227] Further, the present specification has disclosed an
electronic endoscope characterized in that the drive mechanism
includes a lens holder for supporting the objective lens, a feed
screw extending along the axis of the outer shell, and a motor for
driving and revolving the feed screw, and wherein the lens holder
engages with a thread groove of the feed screw and revolution about
the feed screw as an axis of revolution is restricted.
[0228] Further, the present specification has disclosed an
electronic endoscope characterized in that the drive mechanism
includes a lens holder for supporting the objective lens, a feed
screw extending along the axis of the outer shell, and a motor for
driving and revolving the lens holder about the feed screw as an
axis of revolution, and wherein the lens holder engages with a
thread groove of the feed screw.
[0229] Further; the present specification has disclosed an
electronic endoscope characterized in that the outer shell is
formed in a cylindrical shape and a thread groove is formed in its
inner peripheral surface, wherein the driving section includes a
lens holder for supporting the objective lens and a motor for
driving and revolving the lens holder about the axis of the outer
shell as an axis of revolution, and wherein the lens holder engages
with the thread groove of the outer shell.
[0230] Further, the present specification has disclosed an
electronic endoscope characterized by comprising a control section
that reads an image pick-up signal from the solid-state imaging
device and that generates image data, and a memory that stores the
image data are further included in the outer shell.
[0231] The electronic endoscope 500 shown in FIGS. 34 to 36
comprises: a body part 511 and a transparent cover 513 serving as
an outer shell; a lens holder 519 that is accommodated inside the
body part 511 and that is provided with an objective lens group 517
serving as a wide-angle lens arranged on one-end side of the
tube-shaped part 515; a raising and lowering driving section 521
for moving the lens holder 519 in the inside of the transparent
cover 513 and the body part 511 in the optical axis direction of
the objective lens group 517; and a solid-state imaging device 523
that receives the object light acquired through the objective lens
group 517 and then converts the light into an electric signal.
[0232] The body part 511 is formed in a closed-bottom cylindrical
shape fabricated from resin material or the like having light
shielding property. Its bottom part (lower side in FIG. 35) 511a is
provided with a tube-shaped battery accommodating part 511b. After
a power battery 525 is mounted, the battery accommodating part 511b
is airtightly closed by a battery lid 527. That is, the power
battery 525 is built in the body part 511 so that the necessity of
power supply from the outside is avoided. This avoids the necessity
of connection of a power supply cable to the body part, and hence
enhances the easy handling of the electronic endoscope 500 itself.
Here, the shape of the body part 511 is not limited to a cylinder,
and may be a tube of another kind, a hollow shape, or the like.
[0233] Further, in the bottom part 511a, in the example shown in
the figure, two hard wiring protection tubes 529 fabricated from
resin are fixed in a protruding manner toward the outside. Then,
wiring for outputting an image signal or the like is allowed to be
inserted through the wiring protection tubes 529. Here, at the time
of use of the electronic endoscope 500, the wiring protection tubes
529 serve also as grip pipes used for inserting or extracting the
entirety of the electronic endoscope 500 into or from a hole or an
abdominal cavity serving as a subject.
[0234] In the inner peripheral surface of the body part 511, ribs
531 extending in the longitudinal direction of the body part 511
are formed and engage with engagement groove 535 formed in the
flange 533 of the lens holder 519, so that revolution of the lens
holder 519 is stopped.
[0235] The transparent cover 513 is formed from hard transparent
resin. The apex part on the tip side is formed in a smooth
hemispherical shape that permits easy insertion into the inside of
a subject. An open end part 513b that is located on the side
opposite to the hemispherical part 513a and has an expanded
diameter and an open end part 511c of the body part 511 are aligned
to each other and fixed by bonding. The transparent cover 513 may
be fabricated by integral molding, or alternatively by joining the
hemispherical part 513a and the open end part 511c by bonding.
Further, light shielding property may be imparted to the
hemispherical part 513a so that it may be prevented that external
light is introduced directly into the objective lens group 517.
Here, it is sufficient that the transparent resin is transparent to
light at a particular wavelength. That is, the material need not be
transparent to visible light.
[0236] The hemispherical part 513a of the transparent cover 513 and
the cylindrical part 513c extending from the hemispherical part
513a to the open end part 513b have a smaller diameter than the
open end part 513b that has almost the same diameter as the
external shape of the body part 511. As such, since the
hemispherical part 513a and the cylindrical part 513c are formed in
a smaller diameter, they are easily inserted into a narrow inside
of a subject. This expands the range of application of the
electronic endoscope 500. Here, the cylindrical part 513c of the
transparent cover 513 may be in the form of a frontward-tapered
shape. In this case, the tip of the transparent cover 513 is easily
inserted into a small hole or a small abdominal cavity. Further,
the hemispherical part 513a and the cylindrical part 513c may be
formed in a diameter that is equal to the external shape of the
body part 511 and that is the same as the open end part 513b. In
this case, no tapered tip is formed. Thus, the strength of the
electronic endoscope 500 is improved and its robustness is
improved.
[0237] The lens holder 519 is fabricated from resin material or the
like and formed in an outer surface shape that follows the inner
surface of the transparent cover 513. The objective lens group (a
wide-angle lens 517A and a lens 517B) is fixed to one-end side of
the tube-shaped part 515 so as to close the opening of the one-end
side apex part. Preferably, the wide-angle lens 517A is composed of
a fish-eye lens. In this case, a circular fish-eye lens is suitable
for observation in the entire circumferential directions where the
inclination angle (angle relative to the lens optical axis) is
large. That is, the wide-angle lens is a wide-angle lens having an
observational field of view that permits observation in the entire
side circumferential directions around the optical axis (the center
axis of the tube-shaped part 515) of the objective lens group 517.
Here, in addition to this configuration, the wide-angle lens 517A
may be composed of a diagonal fish-eye lens, a common wide-angle
lens, or the like. The optical axis of the objective lens group 517
fixed to the lens holder 519 agrees with the center axis direction
of the tube-shaped part 515 of the lens holder 519. Then, in the
tube-shaped part 515 of the lens holder 519, its outer diameter is
formed somewhat smaller than the inner diameter of the cylindrical
part 513c of the transparent cover 513. Thus, the tube-shaped part
515 is allowed to move inside the transparent cover 513 smoothly
without chattering.
[0238] At a position on an extended line of the center axis of the
cylindrical part 513c extended toward the bottom part 511a of the
body part 511, an image pick-up drive unit part 537 is arranged.
The image pick-up drive unit part 537 is mounted and fixed in the
inside of the body part 511 by using a stay member (not shown) in a
state that the peripheral wall of the battery accommodating part
511b provided in the bottom part 511a of the body part 511 serves
as a supporting column. In the example shown in the figure, the
image pick-up drive unit part 537 has three base plates 541, 542
and 543.
[0239] FIG. 37 shows an enlarged perspective view of a part
containing the image pick-up drive unit part 537. The base plate
541 in the lowermost layer (on the bottom part 511a side) is
provided with a control unit 545 containing a driver circuit for
the stepping motor and other circuits. The middle layer the base
plate 542 is provided with an image memory 547 for storing pick-up
image data. The upper layer base plate 543 is provided with an
imaging device 523 composed of a solid-state imaging device such as
a CCD type imaging device and a CMOS type imaging device.
[0240] In the center part of the base plate 543 containing the
center axis of the cylindrical part 513c, a focusing lens holder
549 formed in a cylindrical shape is arranged. Then, the focusing
lens holder 549 accommodates the imaging device 523 in the inside.
Then, a focusing lens 551 is arranged in the upper-end opening part
of the focusing lens holder 549. Thus, the parallel light beam
(object light) L1 guided along the center axis is focused onto the
light acceptance surface of the imaging device 523 by the focusing
lens 551 so that an image is formed.
[0241] Further, a half mirror 553 is arranged in the middle of the
optical path between the objective lens group 517 and the imaging
device 523. Then, emitted light from a light emitting diode (LED)
555 serving as a light emitting body is directed to the objective
lens group 517 by reflection in the half mirror 553, and then
projected as light for illumination L2. That is, the half mirror
553 is arranged at a position in the immediate upstream of the
focusing lens 551 within the parallel light beam entering the
focusing lens 551 in a state that the half mirror 553 is inclined
by 45 degrees relative to the optical axis of the parallel light
beam (the center axis of the cylindrical part 513c). Then, an
illumination lens 557 for deflecting the light for illumination
into the form of a parallel light beam toward the half mirror 553
is provided between the LED 555 and the half mirror 553. The half
mirror 553, the illumination lens 557, and the LED 555 are fixed
inside the body part 511 individually by appropriate support
members.
[0242] Here, as shown in FIGS. 38A and 38B, the tube-shaped part
515 of the lens holder 519 provided with the objective lens group
517 is allowed to move in the inside of the transparent cover 513
and the body part 511 in the optical axis direction of the
objective lens group 517 (the center axis direction of the
tube-shaped part 515). That is, the position of the wide-angle lens
517A can be set up arbitrarily between height h1 shown in FIG. 38A
and height hn shown in FIG. 38B.
[0243] Means for moving the lens holder 519 is described below in
detail with reference to FIGS. 35, 39A, and 39B. A motor holding
member (not shown) is provided in the inside of the body part 511.
Then, the stepping motor 561 is attached to this motor holding
member. The shaft of the stepping motor 561 is in parallel to the
center axis of the tube-shaped part 515 (the optical axis of the
parallel light beam). A motor gear wheel (spur wheel) 563 is
attached to the shaft of the stepping motor 561. Then, the motor
gear wheel 563 engages with an idle gear wheel 565 composed of a
spur wheel. Then, the idle gear wheel 565 engages with a gear wheel
569 fixed to one-end side of the feed screw 567 by press fit or
bonding. Thus, the revolving force of the stepping motor 561 is
transmitted through the motor gear wheel 563, the idle gear wheel
565, and the gear wheel 569 to the feed screw 567. Here, the idle
gear wheel 565 has a larger number of gear teeth than the motor
gear wheel 563. Thus, the revolution speed of the stepping motor
561 is reduced and then transmitted to the idle gear wheel 565.
Here, the stepping motor 561 for driving the feed screw 567 is not
limited to a motor operated by pulse drive, and may be a motor of a
diverse kind such as a servo motor provided with an encoder, or
alternatively may be a power source of another type.
[0244] As shown in the sectional part view of FIG. 40, in the feed
screw 567, the tip on one-end side is inserted into the shaft hole
513d formed in the flange face of the open end part 513b of the
transparent cover 513. Further, the-other-end side of the feed
screw 567 is supported in a revolvable manner by the support arm
571 provided in the side face of the focusing lens holder 549 of
the image pick-up drive unit part 537. Thus, the feed screw 567
driven and revolved by the revolution of the stepping motor 561.
Here, the stepping motor 561, the motor gear wheel 563, the idle
gear wheel 565, and the gear wheel 569 stay at the same height
position inside the body part 511 regardless of the movement of the
lens holder 519.
[0245] On the other hand, the flange 533 of the lens holder 519 is
provided with an opening 573 for avoiding interference with the
motor gear wheel 563, the idle gear wheel 565, the gear wheel 569,
and the like at a raised position of the lens holder 519 shown in
FIG. 39A. Then, a feed nut 575 screwed onto the feed screw 567 is
fixed to the flange 533 by a nut holding piece 577.
[0246] According to the above-mentioned configuration, the feed
screw 567 and the lens holder 519 provided with the feed nut 575
serve as a linear movement mechanism for moving the lens holder 519
in the axial direction of the feed screw 567 in association with
the revolution operation of the feed screw 567.
[0247] For example, when the stepping motor 561 is driven starting
from the raised position of the lens holder 519 shown in FIG. 39A,
the feed screw 567 is driven and revolved via the motor gear wheel
563, the idle gear wheel 565, and the gear wheel 569. When the feed
screw 567 is driven and revolved, the feed nut 575 screwed onto
this is moved relative to the feed screw 567. As a result, as shown
in FIG. 39B, the lens holder 519 is lowered down from the raised
position.
[0248] FIG. 41 is a functional block diagram showing the image
pick-up drive unit part 537. The control section (CPU) 581 for
collectively controlling the entire system is connected to: a
memory 583 that stores a control program and serves also as a work
memory and that contains the image memory 547 provided on the base
plate 542 described in FIG. 37; an LED drive circuit 585 for
driving the LED 555; an imaging device driver 587 for driving the
imaging device 523; and a pulse generator 591 for providing driving
pulses to the motor driver 589 for driving the stepping motor 561.
Image data obtained by image processing in the control section 581
is stored into the image memory 547 built in the body part 511.
This permits acquisition of an image by the electronic endoscope
500 in a stand alone mode. Thus, easy handling is enhanced.
[0249] Further, the electronic endoscope 500 has a power switch
593. When the power switch 593 is turned ON, electric power from
the power battery 525 is supplied through wiring (not shown) to the
individual parts of the image pick-up drive unit part 537, so that
image pick-up operation and drive operation are performed as
described later.
[0250] For example, the power switch 593 may be provided in the
bottom part 511a of the body part 511, and may be turned ON or OFF
by manual operation. Alternatively, a switch terminal that follows
magnetism may be built in the body part 511. Then, from the outside
of the electronic endoscope 500, a magnet may be brought close or
apart so that the switch terminal may be turned ON or OFF.
[0251] Next, the operation of the electronic endoscope 500 is
described below. As shown in FIGS. 35 and 41, when the power switch
593 is turned ON, electric power is supplied from the power battery
525 to the individual parts so that their operation is started and
hence the stepping motor 561 is driven and revolved. Thus, the lens
holder 519 moves in the inside of the electronic endoscope 500 in
the center axis direction of the tube-shaped part 515, and then
stops at a home position (for example, a raised-end position of the
lens holder 519). Further, emitted light from the LED 555 is
brought into the form of a parallel light beam by the illumination
lens 557. Then, the parallel light beam is reflected to the
direction of the objective lens group 517 by the half mirror 553,
and then projected through the objective lens group 517 over the
entire circumference of the directions (the side face directions
relative to the direction of insertion into the subject) that are
approximately perpendicular to the center axis of the tube-shaped
part 515. As such, the light serves as light for illumination.
[0252] The reflected light from the image-taking object is acquired
through the objective lens group 517 into the electronic endoscope
500. Then, the optical image of the image-taking object travels to
the focusing lens 551 in the form of a parallel light beam. And
then, an image is formed onto the light acceptance surface of the
imaging device 523 by the focusing lens 551. FIG. 42 shows the
situation of the view field region W formed by the objective lens
group 517. The light for illumination emitted from the wide-angle
lens 517A is projected onto the region indicated as the view field
region W. Among the reflected light from the image-taking object
illuminated by the light for illumination, the part of light
belonging to the view field region W is used in image formation and
then acquired by the imaging device 523. Here, in the center part
of the optical axis of the wide-angle lens 517A, a light shielding
mask M for defining the upper end of the view field region W is
provided. In this example, a light shielding mask M having a
circular shape whose radius is set up in correspondence to the view
field region W is provided in the outer surface (the surface on the
light exit side) of the wide-angle lens 517A.
[0253] The image pick-up signal of the image-taking object acquired
by the imaging device 523 is inputted to the control section (CPU)
581 and then undergoes image processing. Then, the obtained data,
for example, in the form of PEG image data is stored into the
memory 583 (the image memory 547).
[0254] FIG. 43 is a flow chart showing the processing procedure of
a control program stored in the memory 583. When the power switch
593 is turned ON, this control program is invoked. Then, first, the
stepping motor 561 is driven so that the lens holder 519 is moved
toward the home position (the raised end position) (S1). The home
position is defined, for example, as a position where the objective
lens group 517 is located on the tip side of the electronic
endoscope 500 as shown in FIGS. 34 and 38A. However, the definition
is not limited to this, and may be the position on the pedestal
side opposite to the tip side (the position of the lens holder
shown in FIG. 38B).
[0255] After the lens holder 519 reaches the home position, image
pick-up processing is performed (S2). The image pick-up processing
includes: processing that the LED 555 is turned ON so that light
for illumination is projected through the objective lens group 517,
and then light reflected from the image-taking object is acquired
through the objective lens group 517 into the electronic endoscope
500 so that an image is formed onto the light acceptance surface of
the imaging device 523; and processing that the imaging device 523
generates an image pick-up signal, then the image pick-up signal of
the image-taking object undergoes image processing, and then the
obtained data is stored into the memory 583 (the image memory
547).
[0256] Then, the stepping motor 561 is driven by a specified number
of pulses (S3), so that the lens holder 519 is lowered by a
predetermined distance. The predetermined distance indicates a step
distance by which the lens holder 519 is to be moved stepwise in
order that the view field region W shown in FIG. 42 should cover
stepwise the movable region of the lens holder 519. For example,
the predetermined distance may be the height La of a part contained
in the view field region W in the cylindrical part 513c of the
transparent cover 513.
[0257] Until the destination reaches the most lowered position of
the lens holder 519 (S4), image pick-up processing is performed at
each destination of the movement (S2). Then, S2 and S3 are repeated
so that an image map as shown in FIG. 44 is generated by combining
the pick-up images obtained by individual occasions of image
pick-up (S5). That is, the pick-up image data IMG(1) of the first
occasion is image data of the view field region W1 over the entire
circumferential directions (circumferential angle from 0 degree to
360 degrees) in a situation that the wide-angle lens 517A of the
objective lens group 517 is located at height h1 shown in FIG. 38A.
The pick-up image data IMG(2) of the second occasion is image data
of the view field region W2 over the entire circumferential
directions in a situation that the wide-angle lens 517A has been
lowered down together with the lens holder 519 from the position of
height h1 by a predetermined distance and hence is located at
height h2. As such, plural sheets of image data IMG(1) to IMG(n)
each obtained at each position of the movement of the lens holder
519 are combined into a substantially single sheet of image data
(image map) by linking the data pieces with each other in the
height direction. Here, in a configuration that a part of the view
field region of an image taking occasion overlaps with the view
field region of the next image taking occasion, even junction
regions of the images are acquired without a missing part. This
provides image data without a gap.
[0258] After the image map is generated from the above-mentioned
pick-up image data IMG(1) to IMG(n), the accumulated data is read
to the outside from the memory 583 (see FIG. 41) storing the image
map. This read operation may be performed by wireless, or
alternatively by using a wiring inserted through the wiring
protection tubes 529 shown in FIG. 34. Alternatively, the memory
583 may be provided in a removable manner from the electronic
endoscope 500. Then, the removed memory 583 may be read by a
personal computer provided separately.
[0259] Further, the electronic endoscope 500 may transmit the
pick-up image data to an external monitor, so that the pick-up
image may be observed on line through the external monitor. In
addition, operation instructions may be inputted from the outside.
In this case, without performing image processing, the control
section 581 transmits the image pick-up signal acquired from the
imaging device 523, to an external video processor in an intact
manner. Then, an object image obtained by image processing by the
video processor is displayed on the external monitor. The
communication between the external video processor, the external
monitor, and the control section 581 may be of cable or wireless.
In a case that the communication is of cable, an external power
source becomes employable when a power source line is included in
the wiring.
[0260] Further, as another example of the control program, a
control program may be employed that, in addition to the control
procedure shown in the flow chart of FIG. 43, allows the view field
region of the objective lens group 517 to be moved to an arbitrary
position in accordance with an operation instruction from the
outside. In this case, selective image pick-up of a desired site is
achieved in accordance with the purpose of image pick-up, and hence
more detailed observation of the site is allowed.
[0261] As described above with reference to the electronic
endoscope 500 serving as an example, the present specification has
disclosed an electronic endoscope that is inserted into a subject
and then acquires an image inside the subject, characterized in
that a lens holder that has a tube-shaped part; a wide-angle lens
that is mounted on the lens holder and that is arranged on one-end
side of the tube-shaped part in a state that an optical axis is
aligned to a center axis of the tube-shaped part so that an
observational field of view extends to a sideward region of the
tube-shaped part; an imaging device that receives light acquired
through the wide-angle lens and that converts the light into an
electric signal; a transparent cover that covers one-end side of
the tube-shaped part and at least whose part facing the
observational field of view of the wide-angle lens has
transparency; a tube-shaped body part that is connected to the
transparent cover on the-other-end side of the tube-shaped part;
and a driving section that is arranged inside the body part and
that causes the lens holder to advance or retreat in the center
axis direction.
[0262] According to this electronic endoscope, the lens holder
inside the transparent cover advances or retreats by virtue of the
driving section. This permits image pick-up at different positions
along the center axis of the tube-shaped part of the lens holder,
and hence image information to be acquired through the wide-angle
lens is allowed to be acquired accurately within the moving range
of the lens holder. Thus, without the necessity of moving the
electronic endoscope within the subject, a continuous image of a
large region is acquired easily.
[0263] Further, the present specification has disclosed an
electronic endoscope characterized in that the imaging device
receives light from an entire sideward circumference of a direction
of insertion into the subject.
[0264] According to this electronic endoscope, image information
for the entire sideward circumference of the direction of insertion
into the subject is acquired, and then the image information is
combined to each other so that a single sheet of entire sideward
circumferential image is generated easily.
[0265] Further the present specification has disclosed an
electronic endoscope characterized in that the wide-angle lens is
composed of a circular fish-eye lens.
[0266] According to this electronic endoscope, since the circular
fish-eye lens is employed, an image of the entire sideward
circumference of the optical axis of the wide-angle lens is
obtained efficiently. Further, this permits image pick-up from a
direction almost perpendicular to the observation surface of the
subject.
[0267] Further, the present specification has disclosed an
electronic endoscope characterized by comprising: a half mirror
that is arranged in the course of the optical path between the
wide-angle lens and the imaging device; and a light emitting body
that emits light for illumination to be projected through the
wide-angle lens after reflection by the half mirror and thereby
illuminates the subject.
[0268] According to this electronic endoscope, the emitted light
from the light emitting body is reflected toward the subject by the
half mirror. Then, this reflected light serves as light for
illumination that illuminates the entire sideward circumference of
the subject.
[0269] Further, the present specification has disclosed an
electronic endoscope characterized in that the tube-shaped part of
the lens holder and a tip part of the transparent cover that covers
the tube-shaped part are formed in a smaller diameter than the body
part.
[0270] According to this electronic endoscope, image information is
acquired by the tip part having a smaller diameter than the body
part. This permits easy insertion even into a narrow region of the
subject and hence easy observation of the inside of the subject.
This expands the range of application of the electronic
endoscope.
[0271] Further, the present specification has disclosed an
electronic endoscope characterized in that the driving section
includes: a feed screw which is supported inside the body part in a
revolvable manner in parallel to the optical axis direction of the
wide-angle lens, a feed nut which is fixed to the lens holder in a
screwed manner onto the feed screw, and a motor which drives and
revolves the feed screw.
[0272] According to this electronic endoscope, the feed screw is
revolved by the motor so that the feed nut screwed onto the feed
screw is moved in the axial direction of the feed screw. By virtue
of this, the lens holder is advanced or retreated in parallel to
the optical axis direction of the wide-angle lens.
[0273] Further, the present specification has disclosed an
electronic endoscope characterized in that a control section that
performs image processing on an image signal obtained by image
pick-up performed by the imaging device and an image memory that
stores image data obtained by image processing performed by the
control section are included in the inside of the body part.
[0274] According to this electronic endoscope, image data obtained
by image processing in the control section is stored into the image
memory built in the body part. This permits acquisition of an image
by the electronic endoscope in a stand alone mode. Thus, easy
handling is enhanced.
[0275] Further, the present specification has disclosed an
electronic endoscope characterized in that a power battery for
supplying electric power to the imaging device and the driving
section is built inside the body part.
[0276] According to this electronic endoscope, the power battery is
built in the body part. This avoids the necessity of power supply
from the outside, and hence avoids the necessity of a power supply
cable connected from the outside of the body part. Thus, easy
handling is enhanced.
[0277] The electronic endoscope 601 shown in FIG. 45 is of
side-viewing type and, at the same time, of hard type. The
electronic endoscope 601 is constructed from: a body part 602 and a
transparent capsule (transparent cover) 603 serving as an outer
shell; and a moving lens frame section (lens holder) 604
accommodated inside and an image pick-up drive unit part 605
described later.
[0278] FIG. 46 is an exploded perspective view of the electronic
endoscope 601. FIG. 47 is a longitudinal sectional view of the
electronic endoscope 601.
[0279] The body part 602 is formed in a closed-bottom cylindrical
shape by using resin material or the like. Then, a tube-shaped
battery accommodating part 602b is provided in its bottom part
(lower side in FIG. 46) 602a. Then, after a power battery 611 is
mounted, the battery accommodating part 602b is closed airtightly
by a battery lid 612. That is, the electronic endoscope 601 is
provided with the power battery 611 in the inside, and hence does
not require other power supply from the outside. Thus, the
electronic endoscope 601 need not be connected to a power supply
cable, and hence permits easy handling.
[0280] Further, in the bottom part 602a, in the example shown in
the figure, two hard grip pipes 613 and 614 fabricated from resin
are fixed in a protruding manner toward the outside. Then, when the
grip pipes 613 and 614 are manipulated by hand, the entirety of the
electronic endoscope 601 is inserted into or extracted from a hole
or an abdominal cavity serving as a subject. The electronic
endoscope 601 may be used in a configuration that wiring is
inserted through the grip pipes 613 and 614.
[0281] In the inner peripheral surface of the body part 602, a
precision female screw 602c is engraved about the axis of the body
part 602. Then, the moving lens frame section 604 provided with a
male screw is screwed in and revolved so that the member 604
advances or retreats in the axial direction.
[0282] The transparent capsule 603 is formed in the form of a tube
body fabricated from hard transparent resin. Its one-end side (rip
side) is formed hemispherical. Then, the open end part 603b on the
side opposite to the hemispherical part 603a is bonded and fixed to
the open end part 602d of the body part 602 in an aligned
orientation. In the example shown in the figure, the entirety of
the capsule section 603 is formed from transparent resin. However,
it is sufficient that at least the part of the cylindrical part
603c serving as an observation window is transparent. The
hemispherical part 603a may be opaque. The observation window
indicates the part faced by a later-described objective lens 617 in
association with revolution of the moving lens frame section.
Further, in place of a configuration that the hemispherical part
603a and the cylindrical part 603c are formed integrally from the
same material, they may be formed as separate members and then
joined and integrated. Here, it is sufficient that the transparent
resin is transparent to light at particular wavelengths such as
infrared light. That is, the material need not be transparent to
visible light.
[0283] Such a configuration may be employed that the hemispherical
part 603a is formed in a yet smaller diameter than that shown in
the figure and that the tip part of the cylindrical part 603c of
the transparent capsule 603 is reduced into a tapered shape and
then connected continuously and smoothly to the hemispherical part
603a. According to this configuration, the tip part of the
transparent capsule 603 is easily inserted even into a smaller hole
or a smaller abdominal cavity. Here, the outer diameter of the
cylindrical part 603c of the transparent capsule 603 and the outer
diameter of the body part 602 are completely identical. Thus, no
level difference occurs between these.
[0284] The moving lens frame section 604 includes: an objective
lens mount part 604a formed in a disk shape by using resin
material; and a cylindrical member 604b having almost the same
diameter as the objective lens mount part 604a. Then, the objective
lens mount part 604a is bonded and fixed integrally at the upper
open end part (in the direction to the tip of the electronic
endoscope 601) of the cylindrical member 604b, so that the open end
part is closed. The outer diameter of the objective lens mount part
604a is formed somewhat smaller than the inner diameter of the
transparent capsule 603. This allows the objective lens mount part
604a to move inside the transparent capsule 603 smoothly without
chattering.
[0285] In the outer peripheral surface of the cylindrical member
604b, a precision male screw 604c screwed into the female screw
602c engraved in the inner peripheral surface of the body part 602
is engraved over the entire length in the axial direction of the
cylindrical member 604b. Further, an internal-tooth gear 604d is
formed in the inner peripheral surface of the cylindrical member
604b. The internal-tooth gear 604d is formed such that gear teeth
parallel to the axis and extending over the entire length in the
axial direction of the cylindrical member 604b are arranged at
equal intervals in the circumferential direction.
[0286] In the center axis part of the objective lens mount part
604a, a cylindrical hole 604e is formed that has a bottom part in
the upper end direction (the direction of the tip of the electronic
endoscope 601). Then, an objective mirror 616 is accommodated in
the cylindrical hole 604e. The objective mirror 616 has a shape
obtained by cutting a cylindrical glass material obliquely at 45
degrees. Then, a reflection film is formed on the obliquely cut
surface at 45 degrees.
[0287] In the objective lens mount part 604a, an image pick-up hole
604f for image pick-up is formed that extends straight in a radial
direction of the disk-shaped member. Then, one-end of the image
pick-up hole 604f is open in the peripheral side face of the
objective lens mount part 604a, and then an objective lens 617
composed of a concave lens is provided in this opening part. The
other end of the image pick-up hole 604f is open toward the
cylindrical hole 604e. Thus, the object light having entered the
image pick-up hole 604f through the objective lens 617 travels in
the form of a parallel light beam, then is reflected by the
above-mentioned 45-degree-oblique reflecting surface of the
objective mirror 616, and then travels along the center axis of the
cylindrical member 604b in the form of a parallel light beam.
[0288] Here, in FIG. 47, in order that the inside of the image
pick-up hole 604f and the above-mentioned parallel light beam
should be seen clearly, illustration is omitted for the gear teeth
of the internal-tooth gear 604d which are to be seen on the far
side of the parallel light beam. Then, the parallel light beam is
shown as a white part.
[0289] The image pick-up drive unit part 605 is mounted and fixed
in the inside of the body part 602 by using a stay member (not
shown) in a state that the peripheral wall of the battery
accommodating part 602b provided in the bottom part 602a of the
body part 602 serves as a supporting column. In the example shown
in the figure, the image pick-up drive unit part 605 has three base
plates 621, 622, and 623.
[0290] The base plate 621 in the lowermost layer (on the bottom
part 602a side) is provided with a control unit 625 containing a
driver circuit for the stepping motor and other circuits. The
middle layer the base plate 622 is provided with an image memory
626 for storing pick-up image data. The upper layer base plate 623
is provided with a solid-state imaging device 627 such as a CCD
type imaging device and a CMOS type imaging device and a stepping
motor 628.
[0291] In the center part of the base plate 623, a lens holder 629
formed in a cylindrical shape is provided. Then, the solid-state
imaging device 627 is accommodated in the inside. Then, a focusing
lens 630 is mounted in the upper-end opening part of the lens
holder 629. Then, the above-mentioned parallel light beam (object
light) entering along the center axis is focused onto the light
acceptance surface of the solid-state imaging device 627 by the
focusing lens 630 so that an image is formed.
[0292] Further, with reference to FIG. 48, in a part in the
immediate upstream of the focusing lens 630 within the parallel
light beam entering the focusing lens 630, a half mirror 631 is
provided that is arranged oblique to the optical axis of the
parallel light beam (the center axis of the cylindrical member
604b). In the example shown in the figure, the reflecting surface
of the half mirror 631 is inclined at 45 degrees relative to the
optical axis of the parallel light beam. However, the inclination
angle may be arbitrary as long as the reflecting surface does not
intersect the optical axis at right angles. The half mirror 631 is
an optical member that allows a part of the incident light to
transmit through and that reflects the remaining part of the
incident light. The ratio of transmission and reflection may be set
up appropriately. Further provided are: an LED 633 for emitting
light for illumination toward the half mirror 631; and an
illumination lens 632 that intervenes between the half mirror 631
and the LED 633 and that projects the light for illumination from
the LED 633, toward the half mirror 631 in the form of a parallel
light beam. The half mirror 631, the illumination lens 632, and the
LED 633 are fixed to the base plate 623.
[0293] The stepping motor 628 is fixed in the periphery part of the
base plate 623. Then, a motor gear wheel (spur wheel) 636 is
attached to the shaft of the stepping motor 628. The shaft of the
stepping motor 628 is oriented in parallel to the center axis of
the cylindrical member 604b (the optical axis of the parallel light
beam). Then, the motor gear wheel 636 engages with an idle gear
wheel 637 composed of a spur wheel.
[0294] The shaft of the idle gear wheel 637 is pivotally supported
in a revolvable manner in a direction perpendicular to the base
plate 623. The idle gear wheel 637 has a larger number of gear
teeth than the motor gear wheel 636. Thus, the revolution of the
stepping motor 628 is slowed down and then transmitted to the idle
gear wheel 637. The idle gear wheel 637 engages with the
internal-tooth gear 604d provided in the inner peripheral surface
of the cylindrical member 604b.
[0295] When the stepping motor 628 revolves, the idle gear wheel
637 revolves. Then, in association with this, the cylindrical
member 604b revolves. When the cylindrical member 604b revolves,
the cylindrical member 604b of the moving lens frame section 604 is
screwed into or out from the body part 602 depending on the
direction of revolution. That is, the moving lens frame section 604
advances or retreats in the axial direction.
[0296] Further, the electronic endoscope 601 has a power switch
(not shown). When the power switch is turned ON, electric power
from the power battery 611 is supplied through wiring (not shown)
to the individual parts of the image pick-up drive unit part 605,
so that image pick-up operation and drive operation are performed
as described later.
[0297] For example, the power switch may be provided in the bottom
part 602a of the body past 602, and may be turned ON or OFF by
manual operation. Alternatively, a switch terminal that follows
magnetism may be built in the body part 602. Then, from the outside
of the electronic endoscope 601, a magnet may be brought close or
apart so that the switch terminal may be turned ON or OFF.
[0298] FIG. 49 is a functional block diagram showing the image
pick-up drive unit part 605. The CPU 641 for collectively
controlling the entire system is connected to: a control memory 642
that stores a control program and serves also as a work memory, an
image memory 626 provided on the base plate 622 described in FIG.
47; an LED drive circuit 643 for driving the LED 633; an imaging
device driver 644 for driving the imaging device 627; and a pulse
generator 646 for providing driving pulses to the motor driver 645
for driving the stepping motor 628.
[0299] When the power switch 647 is turned ON, electric power is
supplied from the power battery 611 to the individual parts so that
operation is started. Thus, the stepping motor 628 is driven and
revolved. Accordingly, the moving lens frame section 604 is
revolved in the inside of the electronic endoscope 601 so as to
advance or retreat in the axial direction.
[0300] With reference to FIGS. 47 and 48, the light for
illumination from the LED 633 is brought into the form of a
parallel light beam by the illumination lens 632, then enters the
half mirror 631, and then is reflected toward the objective mirror
616. The light for illumination having entered the objective mirror
616 is reflected toward the objective lens 617 with maintaining the
form of a parallel light beam. Then, the light for illumination
having entered the objective lens 617 is projected through the
objective lens 617 toward the image-taking object, so as to serve
as light for illumination that illuminates the image-taking object
contained in the view field region of the objective lens 617. That
is, the illumination lens 632, the half mirror 631, the objective
mirror 616, and the objective lens 617 constitute an illumination
optical system.
[0301] The light for illumination is reflected by the image-taking
object. Then, a part of the reflected light serving as object light
enters the objective lens 617. The object light having entered the
objective lens 617 is brought into the form of a parallel light
beam, then travels to the objective mirror 616, then is reflected
by the objective mirror 616, then transmitting through the half
mirror 631 with maintaining the form of a parallel light beam, and
then travels to the focusing lens 630. Then, the object light is
focused onto the light acceptance surface of the solid-stare
imaging device 627 by the focusing lens 630 so that an image is
formed. That is, the objective lens 617, the objective mirror 616,
the half mirror 631, and the focusing lens 630 constitute an
objective optical system.
[0302] As such, the objective optical system and the illumination
optical system share the optical path of the interval between the
half mirror 631 and the objective lens 617. Thus, the light for
illumination emitted from the LED 633 travels, in the reverse
direction, the optical path of the object light in the objective
optical system, then enters the objective lens 617, and then
projected toward the image-taking object. Thus, the image-taking
object contained in the view field region of the objective lens 617
is illuminated reliably.
[0303] Here, in the electronic endoscope 601, the LED 633 is
arranged on the reflected light path of the object light reflected
from the half mirror 631, and the solid-state imaging device 627 is
arranged on the transmitted light path of the object light
transmitted through the half mirror 631. However, the employed
configuration is not limited to this. That is, the LED 633 may be
arranged on the transmitted light path, and the solid-state imaging
device 627 may be arranged on the reflected light path.
[0304] The image pick-up signal of the image-taking object acquired
by the imaging device 627 is acquired into the CPU 641 so as to
undergo image processing, and then stored into the image memory
626, for example, in the form of JPEG image data.
[0305] FIG. 50 is a flow chart showing the processing procedure of
a control program stored in the control memory 642. When the power
switch 647 is turned ON, this control program is started. Then,
first, the stepping motor 628 is driven to the home position side
(step S1). Here, the home position side indicates, for example, the
state shown in FIG. 47 where the objective lens 617 is located on
the tip side of the electronic endoscope 601.
[0306] In the electronic endoscope 601, for the purpose of cost
reduction, a sensor is not provided that detects whether the
stepping motor 628 has reached the home position. Thus, at the next
step S2, it is judged whether a timer for counting a predetermined
time has counted up. Then, when the predetermined time has not yet
elapsed, step S1 is executed repeatedly. In a configuration that a
sensor for detecting reaching to the home position is provided,
step S1 is merely executed repeatedly until reaching to the home
position is detected by the sensor.
[0307] It is sufficient that the predetermined time is defined as
the longest time necessary for the stepping motor 628 to reach the
home position. For example, the state shown in FIG. 52 is a state
that the moving lens frame section 604 has revolved and moved to
the lowermost position. Thus, the predetermined time may be defined
as the time necessary from this state to a state that the moving
lens frame section 604 has revolved in association with the
revolution of the stepping motor 628 so as to have reached the home
position (a position where the moving lens frame section 604 abuts
against the inner peripheral surface of the hemispherical part 603a
and hence cannot move further in this direction) shown in FIG.
47.
[0308] By virtue of this, even in a case that the moving lens frame
section 604 is located wherever in the middle between the state
shown in FIG. 47 and the state shown in FIG. 52 (a state that the
lower end of the cylindrical member 604b abuts against the bottom
part 602a of the body part 602), the objective lens 617 necessarily
reaches the home position when the stepping motor 628 is driven in
the home position direction by the predetermined time.
[0309] When the timer has counted the predetermined time, the
procedure goes from step S2 to step S3 where the contents of a
counter described later is cleared into zero. Then, the procedure
goes to step S4 where image pick-up processing is performed. In the
image pick-up processing: the LED 633 is turned ON so that light
for illumination is projected through the objective lens 617; light
reflected from the image-taking object is acquired through the
objective lens 617 into the electronic endoscope 601; and then the
incident light from the image-taking object is focused onto the
light acceptance surface of the imaging device 627 so that an image
is formed.
[0310] Then, the CPU 641 drives the imaging device 627 via the
imaging device driver 644 so as to acquire from the imaging device
627 the image pick-up signal of the image-taking object obtained by
the imaging device 627, then performs image processing on the
signal, and then stores the data into the image memory 626.
[0311] At the next step S5, the stepping motor 628 is driven by a
specified number of pulses. At the next step S6, this specified
number of pulses is added to the count value in the counter. At the
next step S7, the total count value in the counter is compared with
a specified number.
[0312] Then, when the total count value in the counter does not
reach the specified number, the procedure returns from step S7 to
step S4 so that image pick-up processing is performed. After that,
the processing loop of steps S4 to S7 is executed repeatedly. When
the total count value in the counter has reached the specified
number, the processing shown in FIG. 50 is terminated.
[0313] FIG. 53 is a diagram illustrating the movement of the field
of view of image pick-up of the objective lens 617 in a case that
step S4 in FIG. 50 is executed repeatedly. In the first occasion of
image pick-up processing performed at the home position, an object
image in the field of view indicated by "No. 001" in FIG. 53 is
acquired from the imaging device 627.
[0314] After the image pick-up for the object image of the field of
view "No. 001", the stepping motor 628 is driven at step S5 by a
specified number of pulses. Thus, the cylindrical member 604b
revolves by the specified number of pulses. As a result, the
cylindrical member 604b is screwed and withdrawn into the body part
602. Thus, the next field of view is located at "No. 002" in FIG.
53. Then, an object image in this field of view is taken, and then
the obtained image data is accumulated in the image memory 626.
[0315] After that, during the operation of moving the field of view
like No. 003.fwdarw.No. 004.fwdarw.No. 005 . . . , image pick-up
processing and image data accumulation into the memory 626 are
repeated. FIG. 51 shows a state that the moving lens frame section
604 has gone half around inside the transparent capsule 603
starting from the state shown in FIG. 47. When the moving lens
frame section 604 has gone one around from the home position inside
the transparent capsule 603, the field of view of image pick-up is
located at No. 011 in FIG. 53. In case of having gone around twice,
the field of view of image pick-up is located at No. 021 in FIG.
53.
[0316] Further, FIG. 52 shows a state that the lower end of the
cylindrical member 604b abuts against the bottom part 602a of the
body part 602 and hence cannot move further in this direction. When
the state shown in FIG. 52 is reached, the processing loop of
repeating the image pick-up processing (step S4) is terminated.
Accordingly, the "specified number" used at step S7 in FIG. 50 is
equal to the total number of pulses necessary for reaching from the
home position to the state shown in FIG. 52.
[0317] In the example of movement of the field of view of image
pick-up illustrated in FIG. 53, the specified number of pulses at
step S5 in FIG. 50 is set up such that in the direction of
revolution of the moving lens frame section 604 serving as a lens
holder, adjacent fields of view of image pick-up are positioned
such that their left and right edge parts should be in contact with
each other or overlapping somewhat with each other. Further, the
pitch of the screw threads provided in the inner peripheral surface
of the body part 602 and the outer peripheral surface of the
cylindrical member 604b is designed such that axially adjacent
fields of view of image pick-ups are positioned such that their
upper and lower edge parts should be in contact with each other or
overlapping somewhat with each other.
[0318] By virtue of this, without a missing part over the entirety
of the cylindrical field of view region of the inner peripheral
surface of the image-taking object serving as an observation
object, image pick-up is achieved so that image data is acquired.
Obviously, the number of pulses for the stepping motor may be set
up, or alternatively the pitch of the screws 602c and 604c may be
designed such that larger overlapping parts should be generated in
the fields of view of image pick-up.
[0319] Once image pick-up by the electronic endoscope 601 is
completed, the data accumulated in the image memory 626 shown in
FIG. 49 is to be read to the outside. This read operation may be
performed by wireless, or alternatively by using a wiring inserted
through the grip pipes 613 and 614 shown in FIG. 45. Alternatively,
the image memory 626 may be provided in a removable manner from the
electronic endoscope 601. Then, the removed image memory 626 may be
read by a personal computer provided separately.
[0320] FIG. 54 is a functional block diagram showing a modification
of the image pick-up drive unit part 605. The only difference from
the image pick-up drive unit part 605 shown in FIG. 49 is that
pick-up image data is transmitted to an external monitor so that
the pick-up image is observed on the external monitor on line and
that an operation instruction is allowed to be inputted from the
outside.
[0321] In this case, without performing image processing, the CPU
641 transmits the image pick-up signal acquired from the imaging
device 627, to an external video processor in an intact manner.
Then, the object image obtained by image processing in the video
processor may be displayed on an external monitor. The
communication between the external video processor, the external
monitor, and the CPU 641 may be of cable or wireless. In a case
that the communication is of cable, an external power source
becomes employable when a power source line is included in the
wiring.
[0322] Further, as a control program additional to the control
program shown in FIG. 50, a control program is preferably installed
that in accordance with an operation instruction from the outside,
for example, the view field position of the objective lens 617 it
moved to an arbitrary image pick-up view field position shown in
FIG. 53.
[0323] Here, in the electronic endoscope 601 described above, the
moving lens frame section 604 is driven and revolved by the
stepping motor 628. However, obviously, in place of such a stepping
motor, a motor of any type may be employed as long as the
revolution angle and the revolution length are controlled
accurately.
[0324] As described above with reference to the electronic
endoscope 601 serving as an example, the present specification has
disclosed an electronic endoscope characterized in that a
cylindrical transparent cover at least whose observation window in
a cylindrical part is transparent, a body part that has a
cylindrical part provided continuously to the cylindrical part of
the transparent cover; a lens holder that revolves about the center
axis of the transparent cover in the inside of the transparent
cover and the body part and that moves in the direction of the
center axis; an objective mirror that is provided in the lens
holder and that reflects, toward the body part, light entering
through an objective lens provided at a position facing the
cylindrical part of the transparent cover; an imaging device that
receives light reflected from the objective mirror and that
converts the light into an electric signal; and a driving section
that is provided inside the body part and that drives and revolves
the lens holder so as to drive the lens holder in the center axis
direction.
[0325] Further, the present specification has disclosed an
electronic endoscope characterized in that the lens holder
includes: a disk-shaped member on which the objective lens is
mounted and the objective mirror is mounted; and a cylindrical
member which is provided integrally and continuously to the body
part side of the disk-shaped member.
[0326] Further, the present specification has disclosed an
electronic endoscope characterized by comprising: a female screw
which is formed spirally in the inner peripheral surface of the
body part; and a male screw that is engraved spirally in the outer
peripheral surface of the cylindrical member and engaging with the
female screw and that, when the cylindrical member is driven and
revolved by the driving section, moves the cylindrical member in
the center axis direction.
[0327] Further, the present specification has disclosed an
electronic endoscope characterized in that an optical axis of the
objective lens is provided in a direction perpendicular to an axis
of revolution of the lens holder.
[0328] Further, the present specification has disclosed an
electronic endoscope characterized in that the objective mirror
reflects light entering through the objective lens, toward the body
part along an optical path going along the center axis.
[0329] Further, the present specification has disclosed an
electronic endoscope characterized by comprising a half mirror that
is provided in a course of an optical path of light reflected from
the objective mirror, and a light emitting body for emitting light
for illumination, which is to be reflected by the half mirror and
then reflected by the objective mirror, so as to illuminate a
image-taking object through the objective lens.
[0330] Further, the present specification has disclosed an
electronic endoscope characterized in that a control section which
performs image processing on an image signal obtained by image
pick-up performed by the imaging device and an image memory which
stores pick-up image data obtained by image processing performed by
the control section are built in.
[0331] Further, the present specification has disclosed an
electronic endoscope characterized in that a battery accommodating
part which accommodates a power battery for supplying electric
power to the imaging device and the driving section is built in the
body part.
[0332] An electronic endoscope 701 shown in FIGS. 55 to 57
includes: a body part 602 and a transparent capsule 603 serving as
an outer shell; and a moving lens frame section 604 and an image
pick-up drive unit part 605 accommodated in the inside. Here, like
members to those of the electronic endoscope 601 described above
are designated by like numerals, and functionally common members
are designated by appropriately corresponding numerals. Then, their
description is omitted or simplified.
[0333] In the electronic endoscope 701, a hard grip plate 715
fabricated from resin is bridged between the two grip pipes 613 and
614 fixed in and protruding from the bottom part 602a of the body
part 602. The two grip pipes 613 and 614 and the grip plate 715
constitute a manipulation part used for revolving the outer shell
about the axis of the outer shell. The two grip pipes 613 and 614
are provided approximately symmetric with respect to the axis of
the outer shell. When the grip plate 715 is twisted such that the
grip pipes 613 and 614 are twisted to each other, a torque about
the axis of the outer shell is applied on the outer shell via the
grip pipes 613 and 614. Here, the configuration of the manipulation
part may be arbitrary as long as a torque about the axis of the
outer shell is allowed to be applied on the outer shell.
[0334] Similarly to the case of the electronic endoscope 601
described above, in the electronic endoscope 701, the stepping
motor 628 is driven by a specified number of pulses so that the
moving lens frame section 604 is revolved inside the electronic
endoscope 701 so as to advance or retreat in the axial direction.
In association with this, the field of view is moved like No.
001.fwdarw.No. 002.fwdarw.No. 003 . . . as shown in FIG. 53. In
this manner, image pick-up processing and image data accumulation
into the memory 626 are repeated so that image pick-up is
achieved.
[0335] Once image pick-up by the electronic endoscope 701 is
completed, the data accumulated in the image memory 626 is read to
the outside. Then, when an abnormality such as disease and a wound
is recognized in the image generated from the read-out data, the
image pick-up site where the image data was acquired need be
identified. Thus, in the beginning of image pick-up, the attitude
angle of the outer shell about the axis of the outer shell of the
electronic endoscope 701 is set up at a predetermined angle
relative to the hole serving as a subject by manipulating the
manipulation part composed of the grip pipes 613 and 614 and the
grip plate 715.
[0336] For example, in the state that the moving lens frame section
6C4 is located at the home position shown in FIG. 57, the field of
view of the electronic endoscope 701 is directed to the one grip
pipe 613 side in the direction of arrangement of the two grip pipes
613 and 614. Here, as shown in FIG. 58, a segment L3 is defined as
the segment obtained by joining a reference point P set up
arbitrarily at a position on the open end part of the hole serving
as a subject to the axis O of the housing of the electronic
endoscope 701. Further, a segment L4 is defined as the segment
obtained by joining the grip pipe 613 to the axis O. Then, the
angle (attitude angle) .theta. formed by the segment L3 and the
segment L4 is set up at a predetermined angle. By virtue of this,
the image pick-up site where the image data was acquired is
identified on the basis of the attitude angle .theta., the order of
image pick-up of the image data, and the amounts of displacement of
the field of view in the axial direction and the circumferential
direction at predetermined image pick-up intervals.
[0337] As described above with reference to the electronic
endoscope 701 serving as an example, the present specification has
disclosed an electronic endoscope that is inserted into a hole and
then acquires an image of the inner peripheral surface of the hole,
characterized by comprising: an outer shell that is formed in a
cylindrical shape and whose peripheral wall is provided with a
transparent window part extending in an axial direction; a
solid-state imaging device that is provided inside the outer shell;
an objective optical system that includes an objective lens for
focusing object light through the window part and that forms an
image onto the solid-state imaging device; and a drive mechanism
that causes at least the objective lens in the objective optical
system to move along an axis of the outer shell, wherein a
manipulation part used for revolving the outer shell about the axis
of the outer shell is provided in the bottom part of the outer
shell which faces the opening of the hole.
[0338] Further, the present specification has disclosed an
electronic endoscope characterized in that the window part is
provided over the entire circumference of the outer shell, and that
the drive mechanism causes at least the objective lens in the
objective optical system to revolve about the axis of the outer
shell and thereby moves along the axis of the outer shell.
[0339] Further, the present specification has disclosed an
electronic endoscope characterized in that the manipulation part
includes a plate member which is provided such as to protrude from
the bottom part of the outer shell, and wherein the plate member is
arranged on the axial of the outer shell.
[0340] Further, the present specification has disclosed a method of
image pick-up characterized by comprising the steps of: inserting
an electronic endoscope into a hole; manipulating a manipulation
part provided in the bottom part of the outer shell that faces the
opening of the hole so as to set up the attitude angle of the outer
shell about the axis of the outer shell relative to the hole to a
predetermined angle; and acquiring an image of the inner peripheral
surface of the hole in the course that the drive mechanism moves
the objective lens along the axis of the outer shell.
[0341] Further, the present specification has disclosed a method of
image pick-up characterized in that the window part is provided
over the entire circumference of the outer shell, and wherein the
drive mechanism causes at least the objective lens in the objective
optical system to revolve about the axis of the outer shell and
thereby moves along the axis of the outer shell.
[0342] An electronic endoscope 801 shown in FIGS. 59 and 60
includes: an outer shell having a body part 602 and a transparent
capsule 603; and a moving lens frame section 604 and an image
pick-up drive unit part 605 accommodated in the inside of the outer
shell. Here, like members to those of the electronic endoscope 601
described above are designated by like numerals, and functionally
common members are designated by appropriately corresponding
numerals. Then, their description is omitted or simplified.
[0343] In the electronic endoscope 801, a power switch 847 is
provided. As shown in FIG. 61, in the state that the electronic
endoscope 801 is inserted into a hole serving as a subject, the
power switch 847 can be operated from the outside of the hole. In
the example shown in the figure, the power switch 847 is turned ON
or OFF by manual operation, and is provided in the bottom part 602a
of the body part 602 that faces the opening of the hole. Here, the
power switch 847 may be provided in the battery lid 612 that is
fitted in the opening part of the battery accommodating part 602b
formed in the bottom part 602a and that constitutes a part of the
bottom part 602a. In another exemplary configuration for the power
switch, a remote code may be extracted from the body part 602 to
the outside of the hole and then a manipulation part used for
performing ON-OFF operation may be provided in the end part. In yet
another exemplary configuration for the power switch, a switch
terminal that follows magnetism may be built in the body part 602.
Then, from the outside of the hole, a magnet is brought close to or
apart from the body part 602 so that the switch terminal may be
turned ON or OFF.
[0344] When the power switch 847 is turned ON, as shown in FIG. 62,
electric power from the power battery 611 is supplied through
wiring (not shown) to the individual parts of the image pick-up
drive unit part 605, so that image pick-up operation and drive
operation are performed similarly to the case of the electronic
endoscope 601 described above.
[0345] As described above with reference to the electronic
endoscope 801 serving as an example, the present specification has
disclosed an electronic endoscope that is inserted into a hole and
then acquires an image of the inner peripheral surface of the hole,
characterized by comprising: an outer shell that is formed in a
cylindrical shape and whose peripheral wall is provided with a
transparent window part extending in an axial direction; a
solid-state imaging device that is provided inside the outer shell;
an objective optical system that includes an objective lens for
focusing object light through the window part and that forms an
image onto the solid-state imaging device; a drive mechanism that
causes at least the objective lens in the objective optical system
to move along an axis of the outer shell; a control section that
controls the solid-state imaging device and the drive mechanism;
and an operation switch that operates the control section, wherein
in a state that the electronic endoscope is inserted into the hole,
the operation switch is allowed to be operated from the outside of
the hole.
[0346] Further, the present specification has disclosed an
electronic endoscope characterized in that the operation switch is
provided in the bottom part of the outer shell that faces the
insertion opening of the hole.
[0347] Further, the present specification has disclosed an
electronic endoscope characterized in that the window part is
provided over the entirety of the circumferential wall of the outer
shell, and wherein the drive mechanism causes at least the
objective lens in the objective optical system to revolve about the
axis of the outer shell and thereby moves along the axis of the
outer shell.
[0348] Further, the present specification has disclosed an
electronic endoscope characterized in that the outer shell is
formed in a cylindrical shape and a thread groove is formed in the
inner peripheral surface of the circumferential wall, wherein the
drive mechanism includes a lens holder which supports the objective
lens and a motor which drives and revolves the lens holder about
the axis of the outer shell, and wherein the lens holder engages
with the thread groove of the outer shell.
[0349] Further, the present specification has disclosed an
electronic endoscope characterized in that the control section
reads an image pick-up signal from the solid-state imaging device
and generates image data, and wherein a memory which stores the
image data is further included in the inside of the outer
shell.
[0350] Further, the present specification has disclosed an
electronic endoscope characterized in that the drive mechanism is
driven by electric power, and wherein a power battery which
supplies electric power to the solid-state imaging device, the
drive mechanism, and the control section is further provided inside
the outer shell.
[0351] In the electronic endoscope 901 shown in FIG. 63, in place
of the objective mirror 616 in the electronic endoscope 601
described above, a half mirror 931 is arranged in the cylindrical
hole 604e of the objective lens mount part 604a. Then, an
illumination lens 932 and an LED 933 is provided behind the half
mirror 931. Here, like members to those of the electronic endoscope
601 described above are designated by like numerals, and
functionally common members are designated by appropriately
corresponding numerals. Then, their description is omitted or
simplified.
[0352] In the electronic endoscope 601 described above, the LED 633
is arranged on the reflected light path of the object light
reflected from the half mirror 631, and the solid-state imaging
device 627 is arranged on the transmitted light path of the object
light transmitted through the half mirror 631. In contrast, in the
electronic endoscope 901, the LED 933 is arranged on the
transmitted light path of the object light transmitted through the
half mirror 931, and the solid-state imaging device 627 is arranged
on the reflected light path of the object light reflected through
the half mirror 931. Even in this configuration, light for
illumination is projected through the objective lens 617 onto the
image-taking object.
[0353] As described above with reference to the electronic
endoscopes 601 and 901 serving as examples, the present
specification has disclosed an electronic endoscope characterized
by comprising: an outer shell that is formed in a tube shape and
whose peripheral wall is provided with a transparent window part
extending in an axial direction; a light source and a solid-state
imaging device that are provided inside the outer shell; an
illumination optical system that projects light for illumination
from the light source through the window part onto an image-taking
object; an objective optical system that includes an objective lens
which focuses object light through the window part and that forms
an image onto the solid-state imaging device; and a drive mechanism
that causes at least the objective lens in the objective optical
system to move along an axis of the outer shell, wherein the
illumination optical system projects the light for illumination
onto the image-taking object through the objective lens.
[0354] Further, the present specification has disclosed an
electronic endoscope characterized in that the illumination optical
system includes a half mirror; the half mirror is arranged on the
optical path of the object light in an inclined manner relative to
the optical axis of the object light in the objective optical
system; the light source is arranged on any one of the transmitted
light path of the object light transmitted through the half mirror
and the reflected light path of the object light reflected from the
half mirror; and the solid-state imaging device is arranged on the
other one of the transmitted light path and the reflected light
path.
[0355] Further, the present specification has disclosed an
electronic endoscope characterized in that the window part is
provided over the entirety of the circumferential wall of the outer
shell, and wherein the drive mechanism causes at least the
objective lens in the objective optical system to revolve about the
axis of the outer shell and thereby moves along the axis of the
outer shell.
[0356] Further, the present specification has disclosed an
electronic endoscope characterized in that the outer shell is
formed in a cylindrical shape and a thread groove is formed in the
inner peripheral surface of the circumferential wall, wherein the
drive mechanism inch ides a lens holder which supports the
objective lens and a motor which drives and revolves the lens
holder about the axis of the outer shell, and wherein the lens
holder engages with the thread groove of the outer shell.
[0357] Further, the present specification has disclosed an
electronic endoscope characterized in that a control section which
reads an image pick-up signal from the solid-state imaging device
and which generates image data and a memory which stores the image
data are further included in the inside of the outer shell.
[0358] Further, the present specification has disclosed an
electronic endoscope characterized in that the drive mechanism is
driven by electric power, and wherein a power battery which
supplies electric power to the solid-state imaging device and the
drive mechanism is further provided inside the outer shell.
[0359] An electronic endoscope 1001 shown in FIGS. 64 to 66
includes: an outer shell having a body part 602 and a transparent
capsule 603; and a moving lens frame section 604 and an image
pick-up drive unit part 605 accommodated in the inside of the outer
shell. Here, like members to those of the electronic endoscope 601
described above are designated by like numerals, and functionally
common members are designated by appropriately corresponding
numerals. Then, their description is omitted or simplified.
[0360] Then, in place of the illumination optical system of the
above-mentioned electronic endoscope 601 which is constructed from
the LED 633, the illumination lens 632, the half mirror 631, the
objective mirror 616, and the objective lens 617, in the electronic
endoscope 1001, the upper part of the objective lens mount part
604a of the moving lens frame section 604 is provided with: a light
emitting diode (LED) 1033 for emitting light for illumination; an
illumination lens 1032 for facing the light for illumination from
the LED 1033 and then projects the light onto the image-taking
object; and a battery 1034 for supplying electric power to the LED
1033.
[0361] The illumination lens 1032 serving as a projection exit of
the light for illumination is arranged above the objective lens 617
such that the lens optical axis of the illumination lens 1032 is in
parallel to the lens optical axis of the objective lens 617 or
alternatively such that the lens optical axis of the illumination
lens 1032 approaches the lens optical axis of the objective lens
617 when going outward from the outer shell. The light for
illumination projected from the illumination lens 1032 onto the
image-taking object illuminates the region containing the view
field region of the objective lens 617. The LED 1033, the
illumination lens 1032, and the battery 1034 are fixed to the
objective lens mount part 604a by fixing members (not shown).
[0362] Here, the illumination lens 1032 serving as a projection
exit of the light for illumination is preferably arranged at a
position adjacent to the objective lens 617 in the axial direction
of the outer shell. By virtue of this, for example, in a case that
an image-taking object located extremely close is to be taken,
illumination of the region containing the view field region of the
objective lens 617 becomes easy.
[0363] In the above-mentioned configuration that the LED 1033 and
the illumination lens 1032 are exposed to the outside of the
objective lens mount part 604a, its ON-OFF state is easily checked
through the transparent capsule 603 and hence a possible trouble is
recognized easily. Further, electric power to the LED 1033 is
supplied from the battery 1034 separate from the power battery 611.
Thus, even in a case that the LED 1033 is of high luminance, its
relatively high power consumption among those of LEDs is
satisfactorily covered by the battery 1034. Thus, this
configuration realizes a clear image.
[0364] In the electronic endoscope 1001, a power switch (not shown)
is provided. When the power switch is turned ON, electric power
from the power battery 611 is supplied through wiring (not shown)
to the individual parts of the image pick-up drive unit part 605.
Further, electric power from the battery 1034 is supplied through
wiring (not shown) to the LED 1033. By virtue of this, image
pick-up operation and drive operation are performed.
[0365] FIG. 67 is a functional block diagram showing the image
pick-up drive unit part 605. The CPU 641 for collectively
controlling the entire system is connected to: a control memory 642
that stores a control program and serves also as a work memory, an
image memory 626 provided on the base plate 622; an LED drive
circuit 643 for driving the LED 1033; an imaging device driver 644
for driving the imaging device 627; and a pulse generator 646 for
providing driving pulses to the motor driver 645 for driving the
stepping motor 628.
[0366] When the power switch 647 is turned ON, electric power is
supplied from the power batteries 611 and 1034 to the individual
parts so that operation is started. Thus, the stepping motor 628 is
driven and revolved. Accordingly, the moving lens frame section 604
is revolved in the inside of the electronic endoscope 1001 so as to
advance or retreat in the axial direction.
[0367] With reference to FIG. 66, the light for illumination from
the LED 1033 enters the illumination lens 1032. Then, the light for
illumination having entered the illumination lens 1032 is
transmitted through the transparent capsule 603 and then projected
toward the image-taking object so as to serve as light for
illumination that illuminates the image-taking object contained in
the view field region of the objective lens 617. That is, the
illumination lens 1032 constitutes an illumination optical
system.
[0368] The light for illumination is reflected by the image-taking
object. Then, a part of the reflected light serving as object light
enters the objective lens 617.
[0369] The object light having entered the objective lens 617 is
brought into the form of a parallel light beam, then travels to the
objective mirror 616, and then is reflected by the objective mirror
616 so as to travel to the focusing lens 630 with maintaining the
form of a parallel light beam. Then, the object light is focused
onto the light acceptance surface of the solid-state imaging device
627 by the focusing lens 630 so that an image is formed.
[0370] The image pick-up signal of the image-taking object acquired
by the imaging device 627 is acquired into the CPU 641 so as to
undergo image processing, and then stored into the image memory
626, for example, in the form of JPEG image data.
[0371] Similarly to the case of the electronic endoscope 601
described above, in the electronic endoscope 1001, the stepping
motor 628 is driven by a specified number of pulses so that the
moving lens frame section 604 is revolved inside the electronic
endoscope 1001 so as to advance or retreat in the axial direction.
In association with this, the field of view is moved like No.
001.fwdarw.No. 002.fwdarw.No. 003 . . . as shown in FIG. 53. In
this manner, image pick-up processing and image data accumulation
into the memory 626 are repeated so that image pick-up is
achieved.
[0372] After the image pick-up of an object image of the field of
view "No. 001" shown in FIG. 53, the stepping motor 628 is driven
by a specified number of pulses. Thus, the moving lens frame
section 604 is revolved by the specified number of pulses. As a
result, the moving lens frame section 604 is screwed and retreats
into the body part 602. In association with this, the objective
lens 617 held by the moving lens frame section 604 is moved so that
the field of view moves to "No. 002" shown in FIG. 53. At that
time, the LED 1033 and the illumination lens 1032 mounted on the
moving lens frame section 604 are also moved similarly to the
objective lens 617, and thereby follows the moving field of view so
as to illuminate the field of view "No. 002". Then, an object image
in this field of view is taken, and then the obtained image data is
accumulated in the image memory 626.
[0373] FIG. 68 shows a state that the moving lens frame section 604
has gone half around inside the transparent capsule 603 starting
from the state shown in FIG. 66. When the moving lens flame section
604 has gone one around from the home position inside the
transparent capsule 603, the field of view of image pick-up is
located at No. 011 in FIG. 53. In case of having gone around twice,
the field of view of image pick-up is located at No. 021 in FIG.
53.
[0374] Further, FIG. 69 shows a state that the lower end of the
cylindrical member 604b abuts against the bottom part 602a of the
body part 602 and hence cannot move further in this direction. When
the state shown in FIG. 69 is reached, the processing loop of
repeating the image pick-up processing is terminated.
[0375] Once image pick-up by the electronic endoscope 1001 is
completed, the data accumulated in the image memory 626 is to be
read to the outside.
[0376] As described above with reference to the electronic
endoscope 1001 serving as an example, the present specification has
disclosed an electronic endoscope characterized by comprising: an
outer shell that is formed in a tube shape and whose peripheral
wall is provided with a transparent window part extending in an
axial direction; a light source and a solid-state imaging device
that are provided inside the outer shell; an illumination optical
system that projects light for illumination from the light source
through the window part onto an image-taking object; an objective
optical system that includes an objective lens which focuses object
light through the window part and that forms an image onto the
solid-state imaging device; a lens holder that holds at least the
objective lens in the objective optical system; and a driving
section that moves the lens holder along the axis of the outer
shell, wherein the light source and the illumination optical system
are integrally fixed and supported by the lens holder.
[0377] Further, the present specification has disclosed an
electronic endoscope characterized in that the projection exit of
the illumination optical system is arranged at a position adjacent
to the objective lens in the axial direction of the outer
shell.
[0378] Further, the present specification has disclosed an
electronic endoscope characterized in that the window part is
provided over the entire circumference of the peripheral wall of
the outer shell, and wherein the driving section causes the lens
holder to revolve about the axis of the outer shell and thereby
moves along the axis of the outer shell.
[0379] Further, the present specification has disclosed an
electronic endoscope characterized in that the outer shell is
formed in a cylindrical shape and its inner peripheral surface is
provided with a thread groove, wherein the driving section includes
a motor which drives and revolves the lens holder about the axis of
the outer shell, and wherein the lens holder engages with the
thread groove of the outer shell.
[0380] Further, the present specification has disclosed an
electronic endoscope characterized in that a control section which
reads an image pick-up signal from the solid-state imaging device
and then generates image data and a memory which stores the image
data are further included in the inside of the outer shell.
[0381] Further, the present specification has disclosed an
electronic endoscope characterized in that the driving section is
driven by electric power, and wherein a power battery which
supplies electric power to the light source, the solid-state
imaging device, and the driving section are further provided inside
the outer shell.
[0382] An electronic endoscope 1101 shown in FIGS. 70 to 72
includes: a body part 602 and a transparent capsule 603 that
constitute an outer shell; a moving lens frame section 604
accommodated in the inside; and an imaging unit part 1105 and a
storage and driving section 1106 described later. Here, like
members to those of the electronic endoscope 601 described above
are designated by like numerals, and functionally common members
are designated by appropriately corresponding numerals. Then, their
description is omitted or simplified.
[0383] In the electronic endoscope 601 described above, the body
part 602 and the transparent capsule 603 were fixed to each other
by bonding. In contrast, in the electronic endoscope 1101, the body
part 602 and the transparent capsule 603 are fixed to each other by
screwing. That is, a screwing protrusion part 602e having a
somewhat smaller diameter than the body part 602 protrudes from the
open end part 602d of the body part 602. Then, a male screw is
engraved spirally in the outer peripheral surface of the screwing
protrusion part 602e. Further, in the inner peripheral surface of
the open end part 603b on the side opposite to the hemispherical
part 603a of the transparent capsule 603, a female screw is
engraved spirally that screws into the male screw in the screwing
protrusion part 602e on the body part 602 side.
[0384] The imaging unit 1105 individual colors base plates 1121 and
1122. The base plates 1121 and 1122 are mounted on and fixed to the
objective lens mount part 604a inside the cylindrical member 604b
at a position departing from the cylindrical member 604b. In the
base plate 1121 arranged on the upper side (the objective lens
mount part 604a side), a cylindrical lens holder 1129 is arranged
in the center part. Then, a solid-state imaging device 1127 is
mounted on the base plate 1121 in the inside.
[0385] A focusing lens 1130 is mounted in the upper opening of the
lens holder 1129. Then, the parallel light beam reflected by the
objective mirror 616 is focused by the focusing lens 1130 so that
an image is formed onto the light acceptance surface of the
solid-state imaging device 1127.
[0386] The moving lens frame section 604 includes: an LED 1133
installed on the upper part of the objective lens mount part 604a;
and an illumination lens 1132 arranged in front of the LED 1133.
The LED 1133 emits light for illumination. Then, the light for
illumination focused by the illumination lens 1132 illuminates an
image-taking object located in front of the objective lens 617.
[0387] A first control unit 1125 described later is mounted on the
base plate 1122 arranged on the lower side. A battery accommodating
part 1122a is provided in the lower surface of the base plate 1122.
Then, a second power battery 1111b is accommodated here. The second
power battery 111b is mounted in the battery accommodating part
1122a in a situation that the screwing between the female screw
603b of the transparent capsule 603 and the male screw 602e of the
body part 602 is released so that the electronic endoscope 1101 is
disassembled.
[0388] The first control unit 1125 receives driving power from the
second power battery 1111b. Further, the LED 1133 receives driving
power from the second power battery 1111b through wiring (not
shown).
[0389] The storage and driving section 1106 is mounted and fixed in
the inside of the body part 602 by using a stay member (not shown)
in a state that the peripheral wall of the battery accommodating
part 602b provided in the bottom part 602a of the body part 602
serves as a supporting column. The storage and driving section 1106
has a base plate 1123.
[0390] On the base plate 1123, a second control unit 1124 is fixed
and mounted, and a stepping motor 1128 is also fixed and mounted.
Then, a motor gear wheel (spur wheel) 1136 is attached to the shaft
of the stepping motor 1128. The shaft of the stepping motor 1128 is
oriented in parallel to the center axis of the cylindrical member
604b (the optical axis of the parallel light beam). Then, the motor
gear wheel 1136 engages with an idle gear wheel 1137 composed of a
spur wheel.
[0391] The shaft of the idle gear wheel 1137 is pivotally supported
in a revolvable manner in a direction perpendicular to the base
plate 1123. The idle gear wheel 1137 has a larger number of gear
teeth than the motor gear wheel 1136. Thus, the revolution of the
stepping motor 1128 is slowed down and then transmitted to the idle
gear wheel 1137. The idle gear wheel 1137 engages with the
internal-tooth gear 604d provided in the inner peripheral surface
of the cylindrical member 604b.
[0392] When the stepping motor 1128 revolves, the idle gear wheel
1137 revolves. Then, in association with this, the cylindrical
member 604b revolves. When the cylindrical member 604b revolves,
the cylindrical member 604b of the moving lens frame section 604 is
screwed into or out from the body part 602 depending on the
direction of revolution. That is, the moving lens frame section 604
advances or retreats in the axial direction.
[0393] In the electronic endoscope 1101, a power switch (not shown)
is provided. When the power switch is turned ON, electric power
from the first power battery 1111a is supplied to the individual
parts of the storage and driving section 1106 through wiring (not
shown) so that drive operation is performed.
[0394] Further, in the imaging unit 1105, a switch terminal that
follows magnetism is built in. When a magnet is brought close or
apart in the outside of the electronic endoscope 1101, the switch
terminal is turned ON or OFF so that power supply from the second
power battery 1111b to the imaging unit 1105 is turned ON or
OFF.
[0395] FIG. 73 is a functional block diagram showing the first
control unit 1125. The CPU 1141 for collectively controlling the
imaging unit 1105 is connected to: a control memory 1142 for
storing a control program and serving also as a work memory; an LED
drive circuit 1143 for driving the LED 1133; an imaging device
driver 1144 for driving the imaging device 1127; and a wireless
communication module 1148 for performing wireless communication
with the second control unit 1124. An antenna 1148a is provided in
the wireless communication module 1148.
[0396] FIG. 74 is a functional block diagram showing the second
control unit 1124. The CPU 1149 for collectively controlling the
entire system is connected to: a control memory 1151 for storing a
control program and serving also as a work memory, an image memory
1126 for storing image data received from the imaging unit 1105 by
wireless; a pulse generator 1146 for providing driving pulses to a
motor driver 1145 for driving the stepping motor 1128; and a
wireless communication module 1152 for performing wireless
communication with the first control unit 1125. An antenna 1152a is
provided in the wireless communication module 1152.
[0397] The CPU 1149 of the second control unit 1124 cooperates with
the CPU 1141 of the first control unit 1125 via wireless
communication.
[0398] When the power switch described above is turned ON, electric
power is supplied from the first power battery 1111a and the second
power battery 1111b to the individual parts so that operation is
started. Then, the motor 1128 is driven and revolved. Accordingly,
the moving lens frame section 604 is revolved in the inside of the
electronic endoscope 1101 so as to advance or retreat in the axial
direction. Further, the emitted light from the LED 1133 is focused
by the illumination lens 1132, and then projected toward the
image-taking object so as to serve as light for illumination.
[0399] The reflected light from the image-taking object is acquired
through the objective lens 617 into the electronic endoscope 1101.
Then, the optical image of the image-taking object reflected by the
objective mirror 616 travels to the focusing lens 1130 in the form
of a parallel light beam, and then is focused onto the light
acceptance surface of the solid-state imaging device 1127 by the
focusing lens 1130 so that an image is formed.
[0400] The image pick-up signal of the image-taking object acquired
by the imaging device 1127 is acquired into the CPU 1141 and then
undergoes image processing so as to be converted, for example, into
JPEG image data. The obtained data is acquired into the CPU 1149
via wireless communication modules 1148 and 1152, and then stored
into the image memory 1126.
[0401] FIG. 75 is a flow chart showing the processing procedure of
a control program stored in the control memory 1151. When the power
switch is turned ON, this control program is started. Then, first,
the stepping motor 1128 is driven to the home position side (step
S1). Here, the home position side indicates, for example, the state
shown in FIG. 72 where the objective lens 617 is located on the tip
side of the electronic endoscope 1101.
[0402] In this embodiment, for the purpose of cost reduction, a
sensor is not provided that detects whether the stepping motor 1128
has reached the home position. Thus, at the next step S2, it is
judged whether a timer for counting a predetermined time has
counted up. Then, when the predetermined time has not yet elapsed,
step S1 is executed repeatedly. In a configuration that a sensor
for detecting reaching to the home position is provided, step S1 is
merely executed repeatedly until reaching to the home position is
detected by the sensor.
[0403] It is sufficient that the predetermined time is defined as
the longest time necessary for the stepping motor 1128 to reach the
home position. For example, the state shown in FIG. 76 is a state
that the moving lens frame section 604 has revolved and moved to
the lowermost position. Thus, the predetermined time may be defined
as the time necessary from this state to a state that the moving
lens frame section 604 has revolved in association with the
revolution of the stepping motor 1128 so as to have reached the
home position (a position where the moving lens frame section 604
abuts against the inner peripheral surface of the hemispherical
part 603a and hence cannot move further in this direction) shown in
FIG. 72.
[0404] By virtue of this, even in a case that the moving lens frame
section 604 is located wherever in the middle between the state
shown in FIG. 72 and the state shown in FIG. 76 (a state that the
lower end of the cylindrical member 604b abuts against the bottom
part 602a of the body part 602), the objective lens 617 necessarily
reaches the home position when the stepping motor 1128 is driven in
the home position direction by the predetermined time.
[0405] When the timer has counted the predetermined time, the
procedure goes from step S2 to step S3 where the contents of a
counter described later is cleared into zero. Then, the procedure
goes to step S4 where image pick-up processing is performed. In the
image pick-up processing: the LED 1133 is turned ON so that light
for illumination is projected through the objective lens 617; light
reflected from the image-taking object is acquired through the
objective lens 617 into the electronic endoscope 1101; and then the
incident light from the image-taking object is focused onto the
light acceptance surface of the imaging device 1127 so that an
image is formed.
[0406] Then, the CPU 1141 drives the imaging device 1127 via the
imaging device driver 1144 so as to acquire from the imaging device
1127 the image pick-up signal of the image-taking object obtained
by the imaging device 1127, then performs image processing, and
then transmits the obtained data to the second control unit 1124.
Then, the CPU 1149 of the second control unit 1124 stores the data
into the image memory 1126.
[0407] At the next step S5, the stepping motor 1128 is driven by a
specified number of pulses. At the next step S6, this specified
number of pulses is added to the count value in the counter. At the
next step S7, the total count value in the counter is compared with
a specified number.
[0408] Then, when the total count value in the counter does not
reach the specified number, the procedure returns from step S7 to
step S4 so that image pick-up processing is performed. After that,
the processing loop of steps S4 to S7 is executed repeatedly. When
the total count value in the counter has reached the specified
number, the processing shown in FIG. 75 is terminated.
[0409] FIG. 77 is a diagram illustrating the movement of the field
of view of image pick-up of the objective lens 617 in a case that
step S4 in FIG. 75 is executed repeatedly. In the fast occasion of
image pick-up processing performed at the home position, an object
image in the field of view indicated by "No. 001" in FIG. 77 is
acquired from the imaging device 1127.
[0410] After the image pick-up for the object image of the field of
view "No. 001", the stepping motor 1128 is driven at step S5 by a
specified number of pulses. Thus, the cylindrical member 604b
revolves by the specified number of pulses. As a result, the
cylindrical member 604b is screwed and withdrawn into the body part
602. Thus, the next field of view is located at "No. 002" in FIG.
77. Then, an object image in this field of view is taken, and then
the obtained image data is accumulated in the image memory
1126.
[0411] After that, during the operation of moving the field of view
like No. 003.fwdarw.No. 004.fwdarw.No. 005 . . . , image pick-up
processing and image data accumulation into the memory 1126 are
repeated. FIG. 78 shows a state that the moving lens frame section
604 has gone half around inside the transparent capsule 603
starting from the state shown in FIG. 72. FIG. 79 shows a state of
one around starting from the state shown in FIG. 72.
[0412] When the moving lens frame section 604 has gone one around
from the home position within the transparent capsule 603, the
field of view of image pick-up is located at No. 011 in FIG. 77. In
case of having gone around twice, the field of view of image
pick-up is located at No. 021 in FIG. 77.
[0413] Further, FIG. 76 shows a state that the lower end of the
cylindrical member 604b abuts against the bottom part 602a of the
body part 602 and hence cannot move further in this direction. When
the state shown in FIG. 76 is reached, the processing loop of
repeating the image pick-up processing (step S4) is terminated.
Accordingly, the "specified number" used at step S7 in FIG. 75 is
equal to the total number of pulses necessary for reaching from the
home position to the state shown in FIG. 76.
[0414] Once image pick-up by the electronic endoscope 1101 is
completed, the data accumulated in the image memory 1126 is to be
read to the outside.
[0415] In the electronic endoscope 1101 described above, the
objective mirror 616 is provided on the center axis. Then, the
light acceptance surface of the imaging device 1127 is provided on
this center axis, and the image pick-up hole 604f is provided
straight in a radial direction. By virtue of this, the objective
mirror 616 bends the optical path by 90 degrees so that the light
beam enters the imaging device 1127 on the center axis. In
contrast, in the present example, the mutual positional relation
between the objective lens 617, the objective mirror 616, and the
imaging device 1127 is fixed regardless of the revolution of the
moving lens frame section 604. Thus, the position of the imaging
device 1127, the position of the objective mirror 616, its
reflection angle, and the direction of the image pick-up hole 604f
may be set up arbitrarily as long as they do not interfere with the
revolution motion of the moving lens frame section 604.
[0416] Further, the above-mentioned description has been given for
a case that the incident light is brought into the form of a
parallel light beam by the objective lens 617 and then is reflected
by the objective mirror 616 with maintaining the form of a parallel
light beam. However, since the mutual position relation between the
objective lens 617, the objective mirror 616, and the imaging
device 1127 is fixed, the form of the light beam is not limited to
a parallel beam. Thus, a zoom lens may be inserted in the middle of
the optical path so that an enlarged image corresponding to the
original image may be acquired.
[0417] As described above with reference to the electronic
endoscope 1101 serving as an example, the present specification has
disclosed an electronic endoscope characterized by comprising: a
transparent cover at least whose observation window in a
cylindrical part is transparent; a body part that has a cylindrical
part provided continuously to the cylindrical part of the
transparent cover; a lens holder that revolves about the center
axis of the transparent cover in the inside of the transparent
cover and the body part so as to move in the direction of the
center axis; an objective mirror that is provided in the lens
holder and that reflects, toward the body part, light entering
through an objective lens provided at a position facing the
cylindrical part of the transparent cover; an imaging device that
is fixed and mounted in the lens holder and that receives the light
reflected from the objective mirror so as to convert the light into
an electric signal; and a driving section that is provided inside
the body part and that drives and revolves the lens holder so as to
drive the lens holder in the center axis direction.
[0418] Further, the present specification has disclosed an
electronic endoscope characterized in that the lens holder
includes: a disk-shaped member on which the objective lens is
mounted and the objective mirror is mounted; and a cylindrical
member provided integrally and continuously to the body part side
of the disk-shaped member.
[0419] Further, the present specification has disclosed an
electronic endoscope characterized by comprising: a female screw
that is engraved spirally in the inner peripheral surface of the
body part; and a male screw that is engraved spirally in the outer
peripheral surface of the cylindrical member, that engages with the
female screw and that, when the cylindrical member is driven and
revolved by the driving section, moves the cylindrical member in
the center axis direction.
[0420] Further the present specification has disclosed an
electronic endoscope characterized in that a control section that
performs image processing onto the image signal acquired by image
pick-up performed by the imaging device and that transmits by
wireless the image data having undergone the image processing is
fixed and mounted in the lens holder.
[0421] Further, the present specification has disclosed an
electronic endoscope characterized in that an image memory which
receives and stores the image data transmitted by wireless as
described above is provided in the body part.
[0422] Further, the present specification has disclosed an
electronic endoscope characterized in that the transparent cover
and the body part are provided continuously to each other by
screwing in a manner permitting disassembly.
[0423] Further, the present specification has disclosed an
electronic endoscope characterized in that the drive power supply
for the imaging device and the drive power supply for the driving
section are provided as separate members.
[0424] The electronic endoscope 1200 shown in FIG. 80 includes: a
body part 1211 serving as an outer shell; a transparent cover 1213
having a tube body at least whose side surface has transparency; an
introductory optical part 1215 accommodated inside the outer shell;
and an image pick-up drive unit part 1217 (see FIG. 81) serving as
an image pick-up section described later.
[0425] FIG. 81 is a longitudinal sectional view of the electronic
endoscope 1200. FIG. 82 is an exploded perspective view of the
electronic endoscope 1200. The body part 1211 is formed in a
closed-bottom cylindrical shape fabricated from resin material or
the like. Its bottom part (lower side in FIG. 81) 1211a is provided
with a tube-shaped battery accommodating part 1211b. After a power
battery 1219 is mounted, the battery accommodating part 1211b is
airtightly closed by a battery lid 1221.
[0426] Further, in the bottom part 1211a, in the example shown in
the figure, two hard grip pipes 1223 and 1225 fabricated from resin
are fixed in a protruding manner toward the outside. Then, when the
grip pipes 1223 and 1225 are manipulated by hand, the entirety of
the electronic endoscope 1200 is inserted into or extracted from a
hole or an abdominal cavity serving as a subject. The electronic
endoscope 1200 may be used in a configuration that wiring is
inserted through the grip pipes 1223 and 1225.
[0427] The transparent cover 1213 is formed from hard transparent
resin. Its one-end part (tip part) is closed and formed in a smooth
hemispherical shape that permits easy insertion into the inside of
a subject. An open end part 1213b that is located on the side
opposite to the hemispherical part 1213a and has an expanded
diameter and an open end part 1211d of the body part 1211 are
aligned to each other and fixed by bonding. The transparent cover
1213 may be fabricated by integral molding. Alternatively, the
hemispherical part 1213a, the open end part 1213b, and the like may
be fixed to the transparent cylinder body by bonding in a
multi-piece configuration. Further, light shielding property may be
imparted to the hemispherical part 1213a so that it may be
prevented that external light is introduced directly into the
objective lens 1277. Here, it is sufficient that the transparent
resin is transparent to light at a particular wavelength. That is,
the material need not be transparent to visible light.
[0428] The transparent cover 1213 having the above-mentioned
configuration so as to cover the introductory optical part 1215 is
formed in a smaller diameter than the body part 1211. Further,
one-end side of the transparent cover 1213 in the form of a tube
body has a smaller diameter than the body part 1211. Thus, a
stepped part (open end part 1213b) whose diameter expands in the
radial direction of the transparent cover 1213 is formed in a part
of the outer shell. That is, the stepped part is formed by the
diameter difference between the transparent cover 1213 and the body
part 1211. When the diameter is reduced in the tip of the
electronic endoscope 1200 as described here, observation of the
inside of the subject becomes easy. This extends the range of
application of the electronic endoscope, like observation of a site
having an extremely small diameter in the subject. Here, the
transparent cover 1213 may be in the form of a frontward-tapered
shape having a stepped part. This configuration permits much easier
insertion of the tip insert part of the body part 1211 into a small
hole or a small abdominal cavity.
[0429] In the inside of the body part 1211, a lens drive ring 1285
serving as a cylindrical revolving body is arranged. On the
transparent cover 1213 side (upper side in the figure) of the lens
drive ring 1285, a moving lens frame 1285c connected to the
introductory optical part 1215 is provided continuously. On the tip
side of the moving lens frame 1285c, an objective lens holding hole
1275a serving as an image pick-up hole is formed. Then, an
objective lens 1277 is fixed to the objective lens holding hole
1275a and then acquire light (object light) from the transparent
cover 1213 side. The light acquired from the sideward region
through the objective lens 1277 is brought into the form of a
parallel light beam, then projected onto the objective mirror 1279
fixed to the inner surface of the moving lens frame 7285c, then
reflected by the 45-degree-oblique reflecting surface of the
objective mirror 1279, and then travels toward the imaging device
1249 along the center axis of the transparent cover 1213 with
maintaining the form of a parallel light beam.
[0430] FIG. 83 shows an enlarged perspective view of a part
containing the image pick-up drive unit part 1217. On the base
plate 1241 in the lowermost layer (on the bottom part 1211a side),
a control unit 1245 is arranged that includes a driver circuit for
the stepping motor serving as a driving source of the raising and
lowering driving section. On the base plate 1242 in the middle
layer, an image memory 1247 for storing pick-up image data is
arranged. On the base plate 1243 in the upper layer, an imaging
device 1249 is arranged that is composed of a solid-state imaging
device such as a CCD type imaging device and a CMOS type imaging
device.
[0431] On the base plate 1243, a focusing lens holder 1251 formed
in a cylindrical shape is arranged. Then, the imaging device 1249
is accommodated inside the focusing lens holder 1251. Then, a
focusing lens 1253 is arranged in the upper-end opening part of the
focusing lens holder 1251. Thus, the guided parallel light beam
(object light) L1 is focused onto the light acceptance surface of
the imaging device 1249 by the focusing lens 1253 so that an image
is formed.
[0432] Further, a half mirror 1255 is arranged in the middle of the
optical path between the introductory optical part 1215 and the
imaging device 1249 so that an illumination optical system is
added. In the illumination optical system, the emitted light from
the light emitting diode (LED) 1257 serving as a light emitting
body is projected as light for illumination L2 toward the
introductory optical part 1215 after the reflection by the half
mirror 1255. That is, the half mirror 1255 is arranged at a
position in the immediate upstream of the focusing lens 1253 within
the parallel light beam entering the focusing lens 1253 in a state
that the half mirror 1255 is inclined by 45 degrees relative to the
optical axis of the parallel light beam (the center axis of the
body part 1211). Then, an illumination lens 1259 for bringing the
light for illumination in the form of a parallel light beam is
arranged between the LED 1257 and the half mirror 1255. The half
mirror 1255, the illumination lens 1259, and the LED 1257 are fixed
inside the body part 1211 individually by appropriate support
members (not shown).
[0433] FIGS. 84A and 84B are diagrams showing operation of the
moving lens frame provided with the objective lens. FIG. 84A is an
enlarged perspective view of a part showing a raised position. FIG.
84B is an enlarged perspective view of a part showing a lowered
position. The introductory optical part 1215 revolves about the
center axis of the transparent cover 1213 and, in accordance with
this, rises or goes lower in the axis direction in the inside of
the transparent cover 1213. The introductory optical part 1215 is
provided at the tip of the tube-shaped moving lens frame 1285c, and
projects light for illumination toward the side along a spiral
trajectory formed in association with the motion that the objective
lens 1277 arranged on the side part of the moving lens frame 1285c
revolves and moves in the axis direction. At the same time, the
introductory optical part 1215 acquires reflected light from the
sideward region so as to transfer the object light to the imaging
device 1249. As shown in FIGS. 81 and 82, the introductory optical
part 1215 is integrated with the lens drive ring 1285 via the
cylindrical moving lens frame 1285c, and hence moves in linkage
with the revolution motion and the raising and lowering motion of
the lens drive ring 1285.
[0434] Next, a movement mechanism for the lens drive ring 1285
having the introductory optical part 1215 is described below. As
shown in FIGS. 81 and 82, in the inner peripheral surface of the
body part 1211, a precision female screw 1211c is engraved about
the axis of the body part 1211. Then, the lens drive ring 1285
provided with a male screw 1285a is screwed into the female screw
1211c. Then, in association with its revolution, the lens drive
ring 1285 advances or retreats in the axial direction. Further, an
annular gear 1285b is formed in the inner peripheral surface of the
lens drive ring 1285. In the annular gear 1285b, gear teeth that
are in parallel to the axis and that extend over the entire length
in the axial direction of the lens drive ring 1285 are formed in
the circumferential direction at equal intervals.
[0435] A stepping motor 1291 is mounted on the base plate 1243 in
the uppermost layer (on the side opposite to the bottom part 1211a
side). Then, a motor gear wheel (spur wheel) 1293 is attached to
the shaft of the stepping motor 1291. The axis of revolution of the
stepping motor 1291 is oriented in parallel to the center axis of
the lens drive ring 1285 (the optical axis of the parallel light
beam). The motor gear wheel 1293 engages with an idle gear wheel
1295 composed of a spur wheel.
[0436] The shaft of the idle gear wheel 1295 is pivotally supported
in a revolvable manner in a direction perpendicular to the base
plate 1243. The idle gear wheel 1295 has a larger number of gear
teeth than the motor gear wheel 1293. Thus, the revolution of the
stepping motor 1291 is slowed down and then transmitted to the idle
gear wheel 1295. The idle gear wheel 1295 engages with the annular
gear 1285b provided in the inner peripheral surface of the lens
drive ring 1285.
[0437] FIGS. 85A to 85C are explanation diagrams for the operation
of the electronic endoscope 1200. FIG. 85A shows a state that the
lens drive ring 1285 has gone half around from the revolution start
position. FIG. 85B shows a state that the lens drive ring 1285 has
gone one around from the revolution start position. FIG. 85C shows
a retreated position where the lens drive ring 1285 has terminated
the revolution. When the stepping motor 1291 is driven so that the
motor gear wheel 1293 is revolved, the idle gear wheel 1295
revolves so that the lens drive ring 1285 revolves. When the lens
drive ring 1285 revolves, depending on the direction of the
revolution, the lens drive ring 1285 is raised or lowered in the
axial direction in the inside of the body part 1211. As such, the
moving lens frame 1285c revolves, and moves in the axial direction
in the inside of the transparent cover 1213. Thus, the moving lens
frame 1285c revolves, and goes straight gradually. By virtue of
this, information on the entire field is reflected by the objective
mirror 1279, and then acquired through the focusing lens 1253 into
the imaging device 1249. The information on the imaging device 1249
is transmitted to the image memory 1247 in appropriate timing, so
that information on the entire field is obtained.
[0438] As described above, the annular gear 1285b, the motor gear
wheel 1293, the idle gear wheel 1295, and the stepping motor 1291
constitute a raising and lowering driving section serving as a
revolution driving section. Further, the female screw 1211c, the
lens drive ring 1285, the male screw 1285a, and the raising and
lowering driving section constitute a driving section.
[0439] The electronic endoscope 1200 has a power switch (not
shown). When the power switch is turned ON, electric power from the
power battery 1219 is supplied through wiring (not shown) to the
individual parts of the image pick-up drive unit part 1217, so that
image pick-up operation and drive operation are performed as
described later.
[0440] For example, the power switch may be provided in the bottom
part 1211a of the body pant 1211, and may be turned ON or OFF by
manual operation. Alternatively, a switch terminal that follows
magnetism may be built in the body part 1211. Then, from the
outside of the electronic endoscope 1200, a magnet may be brought
close or apart so that the switch terminal may be turned ON or
OFF.
[0441] FIG. 86 is a functional block diagram showing the image
pick-up drive unit part 1217. The control section (CPU) 1201 for
collectively controlling the entire system is connected to: a
memory 1203 that stores a control program and serves also as a work
memory and that contains the image memory 1247 provided on the base
plate 1242 described in FIG. 83; an LED drive circuit 1205 for
driving the LED 1257; an imaging device driver 1207 for driving the
imaging device 1249; and a pulse generator 1208 for providing
driving pulses to the motor driver 1209 for driving the stepping
motor 1291. Image data obtained by image processing in the control
section 1201 is stored into the image memory 1247 built in the body
part 1211. This permits acquisition of an image by the electronic
endoscope 1200 in a stand alone mode. Thus, operability is improved
in comparison with a system where the image data is sequentially
transmitted to the outside.
[0442] When the power switch 1202 is turned ON, electric power is
supplied from the power battery 1219 to the individual parts so
that operation is started. Thus, the stepping motor 1291 is driven
and revolved. Accordingly, the moving lens frame 1285c is revolved
in the inside of the electronic endoscope 1200 so as to advance or
retreat in the axial direction. Further; emitted light from the LED
1257 is focused into the form of a parallel light beam by the
illumination lens 1259. Then, the parallel light beam is reflected
toward the objective mirror 1279 by the half mirror 1255, and then
the parallel light beam reflected by the objective mirror 1279 is
projected toward the image-taking object through the objective lens
1277 so as to serve as light for illumination.
[0443] The reflected light from the image-taking object is acquired
through the objective lens 1277 into the electronic endoscope 1200.
Then, the optical image of the image-taking object reflected by the
objective mirror 1279 travels to the focusing lens 1253 in the form
of a parallel light beam, and then is focused onto the light
acceptance surface of the solid-state imaging device 1249 by the
focusing lens 1253 so that an image is formed.
[0444] The image pick-up signal of the image-taking object acquired
by the imaging device 1249 is acquired into the CPU 1201 so as to
undergo image processing, and then stored into the image memory
1247, for example, in the form of JPEG image data.
[0445] FIG. 87 is a flow chart showing the processing procedure of
a control program stored in the memory 1203. When the power switch
1202 is turned ON, this control program is started. Then, first,
the stepping motor 1291 is driven to the home position side (step
S1). Here, the home position side indicates, for example, the state
shown in FIG. 84A where the objective lens 1277 is located on the
tip side of the electronic endoscope 1200.
[0446] In the electronic endoscope 1200, a sensor is not provided
that detects whether the stepping motor 1291 has reached the home
position. Thus, at the next step S2, it is judged whether a timer
for counting a predetermined time has counted up. Then, when the
predetermined time has not yet elapsed, step S1 is executed
repeatedly. In a configuration that a sensor for detecting reaching
to the home position is provided, step S1 is merely executed
repeatedly until reaching to the home position is detected by the
sensor.
[0447] It is sufficient that the predetermined time is defined as
the longest time necessary for the stepping motor 1291 to reach the
home position. For example, the state shown in FIG. 84B is that the
moving lens frame 1285c has revolved and thereby reached the
lowermost position hn. Then, the predetermined time may be defined
as the time necessary for a process that, starting from the
lowermost position, the moving lens frame 1285c revolves in
association with the revolution of the stepping motor 1291 so as to
reach the home position (a position where the moving lens frame
1285c is not allowed to travel further in that direction, for
example, because of abutting against the tip of the transparent
cover 1213) h1 shown in FIG. 84A.
[0448] By virtue of this, even in a case that the moving lens frame
1285c is located wherever in the middle between the state shown in
FIG. 84A and the state shown in FIG. 84B (a state that the lower
end of the lens chive ring 1285 abuts against the bottom part 1211a
of the body part 1211), the objective lens 1277 necessarily reaches
the home position when the stepping motor 1291 is driven in the
home position direction by the predetermined time.
[0449] When the timer has counted the predetermined time, the
procedure goes from step S2 to step S3 where the contents of a
counter described later is cleared into zero. Then, the procedure
goes to step S4 where image pick-up processing is performed. In the
image pick-up processing: the LED 1257 is turned ON so that light
for illumination is projected through the objective lens 1277;
light reflected from the image-taking object is acquired through
the objective lens 1277 into the electronic endoscope 1200; and
then the incident light from the image-taking object is focused
onto the light acceptance surface of the imaging device 1249 so
that an image is formed.
[0450] Then, the CPU 1201 chives the imaging device 1249 via the
imaging device driver 1207 so as to acquire from the imaging device
1249 the image pick-up signal of the image-taking object obtained
by the imaging device 1249, then performs image processing on the
signal, and then stores the data into the image memory 1247.
[0451] At the next step S5, the stepping motor 1291 is driven by a
specified number of pulses. At the next step S6, this specified
number of pulses is added to the count value in the counter. At the
next step S7, the total count value in the counter is compared with
a specified number.
[0452] Then, when the total count value in the counter does not
reach the specified number, the procedure returns from step S7 to
step S4 so that image pick-up processing is performed. After that,
the processing loop of steps S4 to S7 is executed repeatedly. When
the total count value in the counter has reached the specified
number, the processing shown in FIG. 87 is terminated.
[0453] FIG. 88 is a diagram illustrating the movement of the field
of view of image pick-up of the objective lens 1277 in a case that
step S4 in FIG. 87 is executed repeatedly. In the first occasion of
image pick-up processing performed at the home position, an object
image in the field of view indicated by "No. 001" in FIG. 88 is
acquired from the imaging device 1249.
[0454] After the image pick-up for the object image of the field of
view "No. 001", the stepping motor 1291 is driven at step S5 by a
specified number of pulses. Thus, the lens drive ring 1285 revolves
by the specified number of pulses. As a result, the lens drive ring
1285 is screwed and withdrawn into the body part 1211. Thus, the
next field of view is located at "No. 002" in FIG. 88. Then, an
object image in this field of view is taken, and then the obtained
image data is accumulated in the image memory 1247.
[0455] After that, during the operation of moving the field of view
like No. 003.fwdarw.No. 004.fwdarw.No. 005 . . . , image pick-up
processing and image data accumulation into the memory 1203 are
repeated. FIG. 85A shows a state that the moving lens frame 1285c
has gone half around inside the transparent cover 1213 starting
from the state shown in FIG. 85B. When the moving lens frame 1285c
has gone one around from the home position inside the transparent
cover 1213, the field of view of image pick-up is located at No.
011 in FIG. 88. In case of having gone around twice, the field of
view of image pick-up is located at No. 021 in FIG. 88.
[0456] Further, FIG. 85C shows a state that the lower end of the
lens drive ring 1285 abuts against the bottom part 1211a of the
body part 1211 and hence cannot move further in this direction.
When the state shown in FIG. 85C is reached, the processing loop of
repeating the image pick-up processing (step S4) is terminated.
Accordingly, the "specified number" used at step S7 in FIG. 87 is
equal to the total number of pulses necessary for reaching from the
home position to the state shown in FIG. 85C.
[0457] In the example of movement of the field of view of image
pick-up illustrated in FIG. 88, the specified number of pulses at
step S5 in FIG. 87 is set up such that in the direction of
revolution of the moving lens frame 1285c serving as a revolving
body, adjacent fields of view of image pick-up are positioned such
that their left and right edge parts should be in contact with each
other or overlapping somewhat with each other. Further, the pitch
of the screw threads provided in the inner peripheral surface of
the body part 1211 and the outer peripheral surface of the lens
drive ring 1285 is designed such that axially adjacent fields of
view of image pick-ups are positioned such that their upper and
lower edge parts should be in contact with each other or
overlapping somewhat with each other.
[0458] By virtue of this, without a missing part over the entirety
of the cylindrical field of view region of the inner peripheral
surface of the image-taking object serving as an observation
object, image pick-up is achieved so that image data is acquired.
The number of pulses for the stepping motor 1291 may be set up, or
alternatively the pitch of the female screw 1211c and the male
screw 1285a may be designed such that larger overlapping parts
should be generated in the fields of view of image pick-up.
[0459] Once image pick-up by the electronic endoscope 1200 is
completed, the data accumulated in the image memory 1247 shown in
FIG. 83 is to be read to the outside. This read operation may be
performed by wireless, or alternatively by using a wiring inserted
through the grip pipes 1223 and 1225 shown in FIG. 80.
Alternatively, the image memory 1247 may be provided in a removable
manner from the electronic endoscope 1200. Then, the removed image
memory 1247 may be read by a personal computer provided
separately.
[0460] In the electronic endoscope 1200, pick-up image data may be
transmitted to an external monitor so that the pick-up image may be
observed on line through the external monitor. In addition,
operation instructions may be inputted from the outside. In this
case, without performing image processing, the CPU 1201 transmits
the image pick-up signal acquired from the imaging device 1249, to
an external video processor in an intact manner. Then, the object
image obtained by image processing in the video processor may be
displayed on an external monitor. The communication between the
external video processor, the external monitor, and the CPU 1201
may be of cable or wireless. In a case that the communication is of
cable, an external power source becomes employable when a power
source line is included in the wiring.
[0461] According to the electronic endoscope 1200 of the present
embodiment described above, a stepped past (the open end part 1213b
of the transparent cover 1213) is formed in a part of the outer
shell of the electronic endoscope 1200. Then, for example, when
insertion is performed until the stepped part is pressed against
the wall surface of the subject, the tube body is simply and
reliably allowed to reach a narrow and small site located at the
observation position. This permits easy insertion of the electronic
endoscope tip into a narrow and small site, and still permits easy
and accurate acquisition of detailed entire circumferential image
information over a large region. In place of the configuration that
the stepped part is provided in the transparent cover 1213, the
transparent cover 1213 may be formed in a straight shape and the
stepped part may be provided in the body part 1211. As such, the
stepped part may be provided at an arbitrary position in the shaped
outer shell. However, the position of the stepped part is
preferably set up with taking into consideration the insertion
length into the destination of insertion.
[0462] Further, in a case that the stepped part is formed in an
annular shape whose diameter is expanded isotropically relative to
the electronic endoscope 1200, the electronic endoscope is
constructed compact in comparison with a decentered configuration.
Further, in the case of an annular stepped part, even when the
electronic endoscope 1200 is inserted into the subject in an
arbitrary orientation, any circumferential position of the stepped
part is reliably pressed against the wall surface of the subject.
Thus, the tube body of the tip of the electronic endoscope is
allowed to reliably reach a desired observation position.
[0463] That is, as shown in FIG. 89, when the inside of a
small-diameter hole 1297 located on the deep side of a hole 1296
serving as a subject is to be observed, in a straight-pipe shaped
electronic endoscope, it is difficult for the tip part to mach the
small-diameter hole 1297. However, in the electronic endoscope
1200, since the transparent cover serving as an observation window
having a smaller diameter is provided at the tip, insertion into
the small-diameter hole 1297 is guided so that the insertion
operation becomes easy. Further, starting the insertion from the
state shown in FIGS. 89A and 89B, when the inner wall surface 1298
of the entrance of the small-diameter hole 1297 abuts against the
open end part 1213b of the transparent cover 1213 serving as a
stepped part as shown in FIG. 89C, deeper insertion is prevented.
As such, the insertion length is restricted by the stepped part.
Thus, the electronic endoscope 1200 is reliably located at the
target observation position by easy operation in comparison with a
case that insertion operation is performed with paying attention to
the detailed insertion amount. By virtue of this, at the target
observation position, detailed entire circumferential image
information is acquired simply and accurately.
[0464] Here, in place of the form of a flat surface extending in a
direction perpendicular to the direction of insertion of the
electronic endoscope 1200, the stepped part may be formed in an
appropriately arbitrary shape, like a tapered surface whose
diameter is reduced toward the insertion tip side. For example, in
place of construction from a single flat surface, the stepped part
may be constructed from a plurality of surfaces.
[0465] As described above with reference to the electronic
endoscope 1200 serving as an example, the present specification has
disclosed an electronic endoscope for acquiring an image of the
inside of a subject, the electronic endoscope characterized by
comprising: a tube body whose one-end part is closed and whose at
least side surface has transparency; a body part that is provided
continuously to the-other-end side of the tube body so as to form
an outer shell; an introductory optical part that guides external
light acquired through the side of the tube body within the tube
body, toward the axis direction of the tube body; an image pick-up
section that receives the external light introduced from the
introductory optical part so as to convert the light into an
electric signal; and a driving section that causes the introductory
optical part to advance or retreat in the axis direction of the
tube body, wherein the one-end side of the tube body is formed in a
smaller diameter than the body part so that a stepped part which is
constructed from the diameter difference between the tube body and
the body part is formed.
[0466] According to this electronic endoscope, since the stepped
part is formed in a part of the outer shell, for example, when
insertion is performed until the stepped part is pressed against
the wall surface of the subject, the tube body is simply and
reliably allowed to reach a narrow and small site located at the
observation position. This permits easy positioning of the
electronic endoscope tip to a desired position of a narrow and
small site, and still permits easy and accurate acquisition of
detailed entire circumferential image information over a large
region.
[0467] Further, the present specification has disclosed an
electronic endoscope characterized in that the stepped part is
composed of an annular stepped part whose diameter is expanded
isotropic relative to the center axis of the tube body.
[0468] According to this electronic endoscope, since the annular
stepped part whose diameter is expanded isotropic, even when the
electronic endoscope is inserted into a subject in an arbitrary
orientation, any circumferential position of the stepped part is
reliably pressed against the wall surface of the subject. Thus, the
tube body of the tip of the electronic endoscope is allowed to
reliably reach a desired observation position. Further, the
isotropic diameter expansion realizes a compact shape of the
electronic endoscope.
[0469] Further, the present specification has disclosed an
electronic endoscope characterized in that the driving section
includes: a female screw which is formed in the inner peripheral
surface of the cylindrical part of the body part; a revolving body
whose one-end part is connected to the introductory optical part
and whose pedestal part is arranged in the cylindrical part,
wherein a male screw to be screwed into the female screw is formed
in the outer peripheral surface of the pedestal part; and a
revolution driving section which drives and revolves the revolving
body about the center axis of the cylindrical part so as to move
the revolving body in the center axis direction.
[0470] According to this electronic endoscope, light of the
sideward region relative to the direction of insertion into the
subject is acquired continuously in the circumferential direction
by a simple configuration composed of screwing between the male
screw and the female screw.
[0471] Further, the present specification has disclosed an
electronic endoscope characterized in that the revolution driving
section includes: an annular gear whose face width direction is in
parallel to the center axis of the cylindrical part and which is
formed in the inner peripheral surface of the revolving body; a
gear wheel which is arranged inside the revolving body and which
engages with the annular gear; and a motor which drives and
revolves the gear wheel.
[0472] According to this electronic endoscope, when the motor
revolves, the gear wheel revolves. Then, in accordance with this,
the revolving body revolves so as to move in the axial direction in
the inside of the body part. In association with this motion, the
introductory optical part linked to the revolving body revolves and
moves in the axial direction in the inside of the tube body.
[0473] Further, the present specification has disclosed an
electronic endoscope characterized in that, in the introductory
optical part, an image pick-up hole is formed in the peripheral
surface, an objective lens is mounted in the open end part of the
image pick-up hole, and a mirror is mounted that deflects the
optical path to the optical axis of the objective lens.
[0474] According to this electronic endoscope, external light
acquired from the sideward region of the tube body via the
objective lens is deflected to the tube body axial direction by the
mirror in the vicinity of the objective lens. Thus, the optical
path is constructed compact, and hence diameter reduction of the
tube body is allowed.
[0475] Further, the present specification has disclosed an
electronic endoscope characterized by comprising: a half mirror
that is arranged in the middle of the optical path between the
introductory optical part and the imaging device; and a light
emitting body that emits light to be projected through the
introductory optical part after reflection by the half mirror and
thereby illuminates the subject.
[0476] According to this electronic endoscope, the emitted light
from the light emitting body is reflected toward the subject by the
half mirror. Then, this reflected light serves as light for
illumination that illuminates the entire sideward circumference of
the subject.
[0477] Further, the present specification has disclosed an
electronic endoscope characterized in that a control section which
performs image processing on an image signal obtained by image
pick-up performed by the image pick-up section and an image memory
which stores image data obtained by image processing performed by
the control section are included in the inside of the body
part.
[0478] According to this electronic endoscope, image data obtained
by image processing in the control section is stored into the image
memory built in the body part. This permits acquisition of an image
by the electronic endoscope in a stand alone mode. Thus, easy
handling is enhanced.
[0479] Further, the present specification has disclosed an
electronic endoscope characterized in that a power battery which
supplies electric power to the image pick-up section and the
driving section is built inside the body part.
[0480] According to this electronic endoscope, the power battery is
built in the body part. This avoids the necessity of power supply
from the outside, and hence avoids the necessity of a power supply
cable connected from the outside of the body part. Thus, easy
handling is enhanced.
[0481] The electronic endoscope 1301 shown in FIGS. 90 to 92
includes an outer shell composed of the body part 1311 and the
transparent cover 1313. Then, its inside is provided with: a lens
holder 1319 that holds an objective lens 1317 for focusing object
light through the transparent cover 1313; a driving section 1321
for moving the lens holder 1319 in the inside of the outer shell;
and a solid-state imaging device 1323 that receives the object
light acquired through the objective lens 1317 and then converts
the light into an electric signal.
[0482] The body part 1311 constituting a part of the outer shell is
fabricated from resin material or the like having light shielding
property and formed into a cylindrical shape whose one-end part
1311a is closed and whose the other end part 1311c is open. The
closed end part (bottom part) 1311a is provided with a tube-shaped
battery accommodating part 1311b. The battery accommodating part
1311b is closed by a battery lid 1327 after a power battery 1325 is
mounted.
[0483] In the example shown in the figure, in the bottom part
1311a, two pipes 1329 protrude outward from the outer shell. For
example, in a case that image data and an image map stored in a
memory 1383 described later are to be transferred to an external
device, data transfer cables are inserted through and protected by
the pipes 1329. The pipes 1329 may be fabricated from soft
material, or alternatively may be fabricated from hard material so
as to serve as a grip used for inserting or extracting the
electronic endoscope 1301 into or from a hole serving as a subject
during the use of the electronic endoscope 1301.
[0484] The transparent cover 1313 formed in a cylindrical shape
whose one-end part 1313b is open. In the transparent cover 1313,
the open end part 1313b is aligned with the open end part 1311c of
the body part 1311, and then fixed to the body part 1311 by
appropriate means such as bonding.
[0485] The other end part (tip part) 1313a of the transparent cover
1313 is formed in a smooth hemispherical shape for permitting easy
insertion into a hole serving as a subject. Then, the tip part
1313a and the open end part 1313b are connected by a cylindrical
part 1313c having the same diameter as the tip part 1313a. In the
electronic endoscope 1301, the tip part 1313a and the cylindrical
part 1313c are formed in a smaller diameter than the open end part
1313b. As such, since the hemispherically formed tip part 1313a and
the cylindrical part 1313c are formed in a small diameter, easy
insertion into a narrow hole is achieved so that the range of
application of the electronic endoscope 1301 is expanded.
[0486] The transparent cover 1313 having the above-mentioned
configuration is fabricated from transparent resin material or the
like by integral molding or the like. Alternatively, the
hemispherically formed tip part 1313a, the open end part 1313b, and
the cylindrical part 1313c may be fabricated as separate members,
and then may be joined to each other by appropriate means as such
bonding. In this case, at least the cylindrical part 1313c serving
as a window part facing the inner peripheral surface of a hole
serving as a subject is formed transparent. Here, in the present
invention, the term "transparent" indicates that the material is
transparent to light at a particular wavelength sensitive to the
imaging device 1323. That is, the material need not be transparent
to visible light.
[0487] The lens holder 1319 is formed from resin material or the
like and has: a cylindrical to-be-driven section 1333 fit into the
body part 1311; and a cylindrical support part 1315 that is formed
in a smaller diameter than the to-be-driven section 1333 and that
can enter the cylindrical part 1313c of the transparent cover
1313.
[0488] In the outer peripheral surface of the to-be-driven section
1333 of the lens holder 1319, a male screw 1333b is formed that is
screwed into the thread groove 1311d formed in the inner peripheral
surface of the body part 1311. Further, in the inner peripheral
surface of the to-be-driven section 1333, an internal-tooth gear
1333a is formed. The gear teeth of the internal-tooth gear 1333a
extend in parallel to the center axis of the to-be-driven section
1333, and are formed at equal intervals in the circumferential
direction.
[0489] Further, in the support part 1315 of the lens holder 1319,
its outer diameter is formed somewhat smaller than the inner
diameter of the cylindrical part 1313c of the transparent cover
1313 so that the support part 1315 moves in the inside of the
cylindrical part 1313c along the center axis of the outer shell
smoothly without chattering.
[0490] In the tip part of the support part 1315, a mirror 1316 is
accommodated. The mirror 1316 is formed in an approximately
cylindrical shape. Its lower end has a shape having been cut by a
plane intersecting the center axis at 45 degrees. This inclined cut
plane is formed into an objective reflecting surface 1316b by
formation of a reflection film or the like.
[0491] Then, an image pick-up hole is formed at a site in the
support part 1315 facing in a radial direction the objective
reflecting surface 1316b of the mirror 1316. Then, the objective
lens 1317 is attached in this image pick-up hole. Then, object
light is focused along the cylindrical part 1313c of the
transparent cover 1313 by the objective lens 1317 so as to travel
to the mirror 1316 in the form of a parallel light beam. Then, the
object light is reflected by the objective reflecting surface 13166
of the mirror 1316, travels along the center axis of the support
part 1315 that agrees with the center axis of the outer shell with
maintaining the form of a parallel light beam.
[0492] In the inside of the body part 1311, an image pick-up drive
unit part 1337 is arranged at a position located on an extended
line of the center axis of the support part 1315 of the lens holder
1319. The image pick-up drive unit part 1337 is fixed inside the
body part 1311 by a fixing member (not shown). In the example shown
in the figure, the image pick-up drive unit part 1337 has three
base plates 1341, 1342, and 1343.
[0493] The solid-state imaging device 1323 is provided on a base
plate 1343 arranged most adjacent to the lens holder 1319. The
imaging device 1323 may be a CCD type imaging device, a CMOS type
imaging device, or the like. A memory 1383 is mounted on a base
plate 1342 arranged under the base plate 1343 (on the bottom part
1311a side of the body part 1311). The memory 1383 stores image
data and the like generated from image pick-up signals read out
from the imaging device 1323. Further, a control unit 1345 is
mounted on a base plate 1341 arranged under the base plate 1342.
The control unit 1345 performs, for example, read of image pick-up
signals from the imaging device 1323 and generation of image data
on the basis of the read-out image pick-up signals.
[0494] The imaging device 1323 is arranged on the base plate 1343
at a position located on an extended line of the center axis of the
support part 1315 of the lens holder 1319. Then, a focusing lens
1351 is arranged at a position located above the imaging device
1323 and located on an extended line of the center axis of the
support part 1315. The focusing lens 1351 is held by a focusing
lens holder 1349 provided on the base plate 1343 in a manner of
surrounding the imaging device 1323. The focusing lens 1351 causes
the object light traveling in the form of a parallel light beam
along the center axis of the support part 1315 to be focused on the
light acceptance surface of the imaging device 1323 so that image
formation is achieved. As such, the objective lens 1317, the
objective reflecting surface 1316b of the mirror 1316, and the
focusing lens 1351 constitute an objective optical system.
[0495] The electronic endoscope 1301 includes a light emitting
diode (LED) 1355 serving as a light source for emitting light for
illuminating the image-taking object. The LED 1355 is accommodated
in the tip part 1313a of the transparent cover 1313 in such a
manner that the LED 1355 is departing from the solid-state imaging
device 1323 in the axial direction of the outer shell and that the
lens holder 1319 intervenes between the LED 1355 and the imaging
device 1323. Further, in the inside of the tip part 1313a,
accommodated are: a battery 1356 for supplying electric power to
the LED 1355; and an illumination lens 1357 for focusing the light
for illumination from the LED 1355. The LED 1355, the battery 1356,
and the illumination lens 1357 are fixed to the tip part 1313a of
the transparent cover 1313 by a holding member 1358.
[0496] At the tip of the support part 1315 of the lens holder 1319,
a through-hole 1315a is formed that exposes the upper end part of
the mirror 1316 accommodated in the tip part. The upper end part of
the mirror 1316 has a shape having been cut by a plane intersecting
the center axis. The inclined cut plane is formed into an
illumination reflecting surface 1316a by formation of a reflection
film or the like. The light for illumination from the LED 1355
transmits through the illumination lens 1357, then travels along
the extended line of the center axis of the support part 1315, and
then enters the illumination reflecting surface 1316a of the mirror
1316 exposed through the through-hole 1315a.
[0497] The illumination reflecting surface 1316a of the mirror 1316
is inclined approximately symmetrically to the objective reflecting
surface 1316b with respect to a virtual surface that is located in
between relative to the objective reflecting surface 1316b and that
is perpendicular to the center axis. Then, in the support part 1315
of the lens holder 1319, a projection exit 1315b is formed at a
site that is located above the objective lens 1317 and that faces
the illumination reflecting surface 1316a of the mirror 1316 in a
radial direction. The light for illumination having entered the
illumination reflecting surface 1316a is reflected by the
illumination reflecting surface 1316a toward the projection exit
1315b, and then projected from the projection exit 1315b through
the cylindrical part 1313c of the transparent cover 1313 onto the
image-taking object.
[0498] The inclination angle of the illumination reflecting surface
1316a is set up appropriately such that the optical axis of the
light for illumination projected from the projection exit 1315b is
in parallel to the lens optical axis of the objective lens 1317 or
alternatively approaches the lens optical axis of the objective
lens 1317 when going outward from the outer shell. The aperture
diameter of the projection exit 1315b is also set up appropriately.
Thus, the light for illumination projected from the projection exit
1315b onto the image-taking object illuminates the region
containing the view field region of the objective lens 1317. Here,
the projection exit 1315b is preferably arranged at a position
adjacent to the objective lens 1317 in the axial direction of the
outer shell. By virtue of this, for example, in a case that an
image-taking object located extremely close is to be taken,
illumination of the region containing the view field region of the
objective lens 1317 becomes easy.
[0499] As such, the illumination lens 1357, the illumination
reflecting surface 1316a of the mirror 1316, and the projection
exit 1315b constitute an illumination optical system. Here, the
objective reflecting surface 1316b of the objective optical system
and the illumination reflecting surface 1316a of the illumination
optical system are formed in the mirror 1316. Thus, the optical
member is shared by the objective optical system and the
illumination optical system. This reduces the number of components
and hence realizes size reduction.
[0500] In the lens holder 1319 in which the male screw 1333b formed
in the outer peripheral surface of the to-be-driven section 1333 is
screwed into the thread groove 1311d formed in the inner peripheral
surface of the body part 1311, its movement is guided along the
center axis of the body part 1311, that is, along the center axis
of the outer shell. The driving section 1321 for moving the lens
holder 1319 along the center axis of the outer shell is described
below in detail.
[0501] A stepping motor 1361 is fixed inside the body part 1311.
Further, an idle gear wheel 1365 is provided that is located
between and engaging with both of the motor gear wheel 1363 of the
stepping motor 1361 and the internal-tooth gear 1333a formed in the
to-be-driven section 1333 of the lens holder 1319. The revolution
of the stepping motor 1361 is transmitted through the motor gear
wheel 1363 and the idle gear wheel 1365 to the lens holder 1319.
Hem, as the source of power for driving and revolving the lens
holder 1319 is not limited to a stepping motor operated by pulse
drive, and may be a motor of a diverse kind such as a servo motor
provided with an encoder, or alternatively may be a power source of
another type.
[0502] In the lens holder 1319, the to-be-driven section 1333 is
fit into the body part 1311. Thus, when revolution of the stepping
motor 1361 is transmitted, the lens holder 1319 revolves about the
center axis of the body part 1311. At the same time, by using the
male screw 1333b formed in the outer surface, the to-be-driven
section 1333 is screwed into the thread groove 1311d formed in the
inner peripheral surface of the body part 1311 Thus, in association
with revolution about the center axis of the body part 1311, the
lens holder 1319 moves (is raised or lowered) along the center axis
of the body part 1311.
[0503] For example, in a situation that the lens holder 1319 is
located at a raised position shown in FIG. 92, the stepping motor
1361 is revolved in a predetermined direction so that the lens
holder 1319 is revolved via the motor gear wheel 1363 and the idle
gear wheel 1365. FIG. 93 shows a state that the lens holder 1319
has gone half around. As shown in FIG. 93, the lens holder 1319
revolves about the center axis of the body part 1311 so as to be
lowered by .DELTA.h along the center axis of the body part 1311.
Then, in accordance with the revolution of the lens holder 1319,
the objective lens 1317 is also revolved so that the field of view
of image pick-up moves in the circumferential direction. The lens
holder 1319 is allowed, in association with the revolution, to be
lowered along the center axis of the body part 1311 up to the
lowermost position shown in FIG. 94, that is, a position where the
lower end of the male screw 1333b of the to-be-driven section 1333
reaches the lower end of the thread groove 1311d of the body part
1311.
[0504] FIG. 95 is a functional block diagram showing the image
pick-up drive unit part 1337. In the image pick-up drive unit part
1337, the control unit 1345 includes: an LED drive circuit 1385 for
driving the LED 1355; an imaging device driver 1387 for driving the
imaging device 1323; a motor driver 1389 for driving the stepping
motor 1361; a pulse generator 1391 for providing driving pulses to
the motor driver 1389; and a control section (CPU) 1381 for
controlling the operation of the LED drive circuit 1385, the
imaging device driver 1387, and the pulse generator 1391. Further,
the memory 1383 stores a control program for the control unit 1345.
Here, the memory 1383 stores a control program, stores image data,
and serves also as a work memory. The control section 1381 performs
appropriate image processing onto image pick-up signals read from
the imaging device 1323, so as to generate image data, and then
stores the generated image data into the memory 1383. This
configuration allows the electronic endoscope 1301 in a stand alone
mode to acquire and save images of image-taking objects. This
provides excellence in easy handling.
[0505] When the power switch 1393 of the electronic endoscope 301
is closed, electric power from the power battery 1325 and the
battery 1356 is supplied to the individual parts of the electronic
endoscope 1301 through wiring (not shown) so that image pick-up is
performed. For example, the power switch 1393 may be provided in
the bottom part 1311a of the body part 1311, and may be opened or
closed by manual operation. Alternatively, a switch terminal that
follows magnetism may be built in the body part 1311. Then, from
the outside of the electronic endoscope 1301, a magnet may be
brought close or apart so that the switch terminal may be opened or
closed.
[0506] Next, the operation of the electronic endoscope 1301 is
described below. When the power switch 1393 is turned ON, electric
power is supplied from the power battery 1325 and the battery 1356
to the individual parts of the electronic endoscope 1301. Then, the
light for illumination from the LED 1355 is projected from the
projection exit 1315b through the cylindrical part 1313c of the
transparent cover 1313 toward the sideward region so that the
image-taking object is illuminated. Reflected light from the
image-taking object is acquired into the electronic endoscope 1301
through the cylindrical part 1313c and the objective lens 1317 of
the transparent cover 1313, so that an image is formed onto the
light acceptance surface of the imaging device 1323 by the focusing
lens 1351. Then, charge accumulated in the imaging device 1323 as a
result of photoelectric conversion is read as an image pick-up
signal by the control section 1381 of the control unit 1345. The
control section 1381 performs appropriate image processing onto the
read-out image pick-up signal so as to generate image data, and
then stores the generated image data into the memory 1383.
[0507] FIG. 96 is a flow chart showing the processing procedure of
a control program of the control unit 1345. When the power switch
1393 is turned ON, first, the stepping motor 1361 is driven and
revolved, so that the lens holder 1319 goes along the center axis
of the outer shell of the electronic endoscope 1301 to a home
position (step S1). Here, in the following description, the home
position is defined as a position where, for example, as shown in
FIG. 92, the objective lens 1317 is located on the tip side of the
electronic endoscope 1301. However, the definition is not limited
to this, and may be the opposite position where the objective lens
1317 is located on the pedestal side (the position shown in FIG.
94).
[0508] After the lens holder 1319 is set at the home position,
image pick-up processing is performed (step S2). The image pick-up
processing includes such processes that the LED 1355 is driven so
as to emit light for illumination; object light is acquired through
the objective lens 1317 into the electronic endoscope 1301 so that
an image is formed onto the light acceptance surface of the imaging
device 1323; and on the basis of the image pick-up signal read from
the imaging device 1323, image data is generated and then stored
into the memory 1383.
[0509] Then, the stepping motor 1361 is driven by a specified
number of pulses (step S3), so that the lens holder 1319 is lowered
by a predetermined distance. Until the lens holder 1319 reaches the
most lowered position (step S4), image pick-up processing is
performed at each destination of the movement (step S2). When the
lens holder 1319 reaches the most lowered position, the lowering
operation of the lens holder 1319 and the image pick-up processing
are terminated (step S4).
[0510] FIG. 97 is a diagram illustrating the movement of the field
of view of image pick-up achieved when the above-mentioned steps S2
to S4 are executed repeatedly. In the first occasion of image
pick-up processing performed at the home position, image pick-up is
performed in the field of view "No. 001", and hence image data of
the field of view "No. 001" is generated from the image pick-up
signal read from the imaging device 1323.
[0511] Once the image pick-up processing in the field of view "No.
001" is completed, the stepping motor 1361 is driven at step S3 by
a specified number of pulses so that the lens holder 1319 is
lowered and revolved. In association with this, the objective lens
1317 held by the lens holder 1319 is moved so that the field of
view moves to "No. 002" in FIG. 97. At that time, the projection
exit 1315b provided in the lens holder 1319 is moved similarly to
the objective lens 1317 and thereby follows the moving field of
view so as to illuminate the field of view "No. 002". Then, image
pick-up is performed in this field of view, and hence image data of
the field of view "No. 002" is generated from the image pick-up
signal read from the imaging device 1323.
[0512] Here, the lens holder 1319 is located in between the LED
1355 and the solid-state imaging device 1323 separated in the axial
direction of the outer shell, and is moved along the axis of the
outer shell. Thus, the optical path length from the LED 1355 to the
solid-state imaging device 1323 is approximately fixed regardless
of the movement of the lens holder 1319. For example, when the lens
holder 1319 is located at the home position shown in FIG. 92, the
objective optical system (the objective lens 1317.fwdarw.the
objective reflecting surface 1316b of the mirror 1316.fwdarw.the
focusing lens 1351.fwdarw.the solid-state imaging device 1323) has
a longer optical path length than the illumination optical system
(the illumination reflecting surface 1316a.fwdarw.the projection
exit 1315b of the LED 1355.fwdarw.the illumination lens
1357.fwdarw.the mirror 1316). In contrast, when the lens holder
1319 is located at the lowermost position shown in FIG. 94, the
optical path length of the illumination optical system is extended,
and the optical path length of the objective optical system is
reduced by the same amount. Thus, the optical path length L5 from
the LED 1355 to the solid-state imaging device 1323 in a situation
that the lens holder 1319 is located at the home position is almost
equal to the optical path length L6 from the LED 1355 to the
solid-state imaging device 1323 in a situation of the lowermost
position. As a result, the intensity of light attenuation by
scattering and the like occurring in the course from the LED 1355
to the solid-state imaging device 1323 becomes almost the same for
these two optical paths. Thus, the intensity of light entering the
solid-state imaging device 1323 is fixed approximately.
[0513] After that, image pick-up processing is repeated with moving
the field of view like "No. 003".fwdarw."No. 004".fwdarw."No. 005"
. . . . When the lens holder 1319 has gone one around from the home
position, the field of view of image pick-up is located at "No.
011" in FIG. 97. In case of having gone around twice, the field of
view of image pick-up is located at "No. 021" in FIG. 97. In the
present embodiment, plural pieces of image data stored in the
memory 1383 are arranged similarly to the exemplary movement of the
field of view shown in FIG. 97 so that an image map is generated
(step S5).
[0514] Here, for example, the number of pulses provided to the
stepping motor 1361 at step S3 may be adjusted appropriately, or
alternatively the screw pitch of the thread groove 1311d of the
body part 1311 and the male screw 1333b of the to-be-driven section
1333 may be adjusted appropriately, so that circumferentially
adjacent fields of view of image pick-up may be positioned such
that their left and right edge parts should be in contact with each
other or overlapping somewhat with each other, and so that axially
adjacent fields of view of image pick-up may be positioned such
that their upper and lower edge parts should be in contact with
each other or overlapping somewhat with each other. According to
this configuration, image taking of an object is achieved without a
missing part in the axial and the circumferential directions. Thus,
an image map without a gap is obtained.
[0515] When the above-mentioned image map has been generated, the
image map is to be read from the memory 1383 to the outside. This
read may be performed by wireless, or alternatively through a cable
in a configuration that a data transfer cable is inserted through
the pipe 1329 shown in FIG. 90 and connected to the image pick-up
drive unit part 1337. Alternatively, the memory 1383 may be
provided in a removable manner from the electronic endoscope 1301.
Then, the removed memory 1383 may be read by a personal computer
provided separately.
[0516] As described above with reference to the electronic
endoscope 1301 serving as an example, the present specification has
disclosed an electronic endoscope characterized by comprising: an
outer shell that is formed in a tube shape and whose peripheral
wall is provided with a transparent window part extending in an
axial direction; a light source and a solid-state imaging device
that are provided inside the outer shell; an illumination optical
system that projects light for illumination from the light source
through the window part onto an image-taking object; an objective
optical system that includes an objective lens which focuses object
light through the window part and that forms an image onto the
solid-state imaging device; a lens holder that holds at least the
objective lens in the objective optical system; and a driving
section that moves the lens holder along the axis of the outer
shell, wherein the light source is arranged departing from the
solid-state imaging device in the axial direction of the outer
shell, wherein the lens holder is moved between the light source
and the solid-state imaging device along the axis of the outer
shell, and wherein the projection exit of the illumination optical
system is provided in the lens holder.
[0517] Further, the present specification has disclosed an
electronic endoscope characterized in that the projection exit of
the illumination optical system is arranged at a position adjacent
to the objective lens in the axial direction of the outer
shell.
[0518] Further, the present specification has disclosed an
electronic endoscope characterized in that: the illumination
optical system includes a first reflecting surface which reflects
the light for illumination toward the projection exit; the
objective optical system includes a second reflecting surface which
reflects the object light toward the solid-state imaging device;
the light source and the solid-state imaging device are arranged on
the same axis; and the first reflecting surface and the second
reflecting surface are formed in a single optical member arranged
on the axis.
[0519] Further, the present specification has disclosed an
electronic endoscope characterized in that the window part is
provided over the entire circumference of the peripheral wall of
the outer shell, and wherein the driving section causes the lens
holder to revolve about the axis of the outer shell and thereby
move along the axis of the outer shell.
[0520] Further, the present specification has disclosed an
electronic endoscope characterized in that the outer shell is
formed in a cylindrical shape and the inner peripheral surface of
its inner wall is provided with a thread groove, wherein the
driving section includes a motor which drives and revolves the lens
holder about the axis of the outer shell, and wherein the lens
holder engages with the thread groove of the outer shell.
[0521] Further, the present specification has disclosed an
electronic endoscope characterized in that a control section which
reads an image pick-up signal from the solid-state imaging device
and then generates image data and a memory which stores the image
data are further included in the inside of the outer shell.
[0522] Further, the present specification has disclosed an
electronic endoscope characterized in that the driving section is
driven by electric power, and wherein a power battery which
supplies electric power to the light source, the solid-state
imaging device, and the driving section is further provided inside
the outer shell.
[0523] Next, preferred examples of use of the electronic endoscopes
described above are given below.
[0524] (i) Example of Use as Hysteroscope
[0525] In recent years, the lowering trend in the age of women
suffering from cervical cancer is growing. In case that cervical
cancer is found at early stages, serious results are avoided by
partial extirpation. Thus, early detection is important.
Nevertheless, women hesitate to expose their own bodies, and hence
the population who receive medical checkup is not growing.
[0526] Each electronic endoscope described above is effective in
medical checkup for cervical cancer, when the dimensions and the
shape are designed appropriately. When the electronic endoscope is
inserted into the vaginal cavity of a woman and then the electronic
endoscope is inserted from the apex part into the uterine cervix
such that a series of the field of view of image pick-up positions
should reach the uterine cervix, image pick-up is achieved for the
situation of the inner peripheral surface of the uterine cervix
without a missing part.
[0527] As a mode of use, for example, the electronic endoscope may
be inserted into the uterine cervix by the patient herself in the
consultation room. Further, the doctor staying in another room may
instruct the insertion position and check the pick-up image through
a monitor on line. This eases the patient's mental burden, and
hence contributes to an increase in the population who receive
medical checkup.
[0528] In particular, at the time when the electronic endoscope
1200 described above is inserted from the inside of the vaginal
cavity further into the canal of the cervix, the inner wall of the
vaginal portion of the cervix at the entrance of the canal of the
cervix abuts against the stepped part of the electronic endoscope
1200 so that the amount of insertion of the electronic endoscope
1200 is restricted. Thus, the tip of the electronic endoscope 1200
is reliably positioned at the inner wall surface of the canal of
the cervix. Further, also from the perspective of the insertion
length, the insertion is stopped at an appropriate position.
[0529] Further, in each electronic endoscope described above, when
the power switch is turned ON, the objective lens returns to the
home position automatically and then image pick-up processing is
performed automatically. Thus, the electronic endoscope may be lent
to the patient, and then the patient herself may acquire an image
of her own uterine cervix in her home. Then, the doctor receives
the electronic endoscope and then checks the pick-up image data in
the memory so that diagnosis is performed.
[0530] (ii) Example of Use as Electronic Endoscope for Large
Intestine and Rectum
[0531] When medical checkup is performed for the large intestine or
the rectum, in the prior art, observation has been performed by
using an electronic endoscope in which an imaging device is mounted
on the tip part. Thus, the diseased part has been observed
obliquely from the above. In contrast, when any one of the
electronic endoscopes described above is inserted to the diseased
part position and then observation is performed, the diseased part
is observed perpendicularly from the above. This permits more
detailed observation and accurate diagnosis.
[0532] (iii) Example of Use as Industrial Endoscope
[0533] Each electronic endoscope described above may be used as an
industrial endoscope, for example, used for observing a fine crack
in a thin piping. At the time, an electronic endoscope is prepared
that has dimensions and a shape in accordance with the size of the
opening of a hole or a gap serving as an observation object as well
as with the insertion depth. As described above, observation of the
crack or the like is performed from the above perpendicularly to
the inner peripheral surface of the hole, and hence more detailed
observation is achieved. Further, once the electronic endoscope is
inserted, observation is allowed for a large region. This reduces
the rate of overlooking small cracks.
INDUSTRIAL APPLICABILITY
[0534] According to the present invention, detailed image
information over a large region is acquired easily and
accurately.
[0535] The present invention has been described above in detail
with reference to particular embodiments. However, it is clear for
the person skilled in the art that various modifications and
variations can be made without departing from the spirit and the
scope of the present invention. The present application is based on
Japanese Laid-Open Patent Application Nos. 2008-157991,
2008-157992, 2008-157993, 2008-157999, 2008-158000, 2008-158002,
2008-158004, 2008-158005, 2008-158006, and 2008-158013 filed on
Jun. 17, 2008. Their contents are incorporated herein by
reference.
REFERENCE SIGNS LIST
[0536] 1 endoscope [0537] 11 body part (outer shell) [0538] 13
transparent cover (outer shell) [0539] 13c cylindrical part (window
part) [0540] 16 objective mirror (objective optical system) [0541]
17 objective lens (objective optical system) [0542] 19 lens holder
[0543] 21 driving section [0544] 23 solid-state imaging device
[0545] 25 power battery [0546] 51 focusing lens (objective optical
system) [0547] 61 stepping motor [0548] 67 feed screw [0549] 81
control section [0550] 83 memory [0551] 500 electronic endoscope
[0552] 511 body part [0553] 511a bottom part [0554] 511b battery
accommodating part [0555] 511c open end part [0556] 513 transparent
cover section [0557] 513a hemispherical part [0558] 513b open end
part [0559] 513c cylindrical part [0560] 513d shaft hole [0561] 515
tube-shaped part [0562] 517 objective lens group [0563] 517A
wide-angle lens [0564] 517B lens [0565] 519 lens holder [0566] 521
raising and lowering driving section [0567] 523 imaging device
[0568] 525 power battery [0569] 527 battery lid [0570] 529 wiring
protection tube [0571] 531 rib [0572] 533 flange [0573] 535
engagement groove [0574] 537 image pick-up drive unit part [0575]
541, 542, 543 base plate [0576] 545 control unit [0577] 547 image
memory [0578] 549 focusing lens holder [0579] 551 focusing lens
[0580] 553 half mirror [0581] 555 light emitting diode [0582] 557
illumination lens [0583] 561 stepping motor [0584] 563 motor gear
wheel [0585] 565 idle gear wheel [0586] 567 feed screw [0587] 569
gear wheel [0588] 571 support arm [0589] 573 opening [0590] 575
feed nut [0591] 577 nut holding piece [0592] 581 control section
[0593] 583 memory [0594] 585 LED drive circuit [0595] 587 imaging
device driver [0596] 591 pulse generator [0597] 593 power switch
[0598] W view field region [0599] 601 electronic endoscope [0600]
602 body part [0601] 602a bottom part [0602] 602b battery
accommodating part [0603] 602c female screw provided in the inner
peripheral surface [0604] 603 transparent capsule (transparent
cover) [0605] 603a hemispherical part at tip [0606] 603c
cylindrical part [0607] 604 moving lens frame section (lens holder)
[0608] 604a disk-shaped objective lens mount part [0609] 604b
cylindrical member [0610] 604c male screw provided in outer
peripheral surface [0611] 604d internal-tooth gear [0612] 604f
image pick-up hole [0613] 605 image pick-up drive unit part [0614]
611 power battery [0615] 612 battery lid [0616] 613, 614 grip pipe
[0617] 616 objective mirror [0618] 617 objective lens [0619] 621,
622, 623 base plate [0620] 626 image memory [0621] 627 solid-state
imaging device [0622] 628 stepping motor [0623] 629 lens holder
[0624] 630 focusing lens [0625] 631 half mirror [0626] 632
illumination lens [0627] 633 LED (light emitting body) [0628] 636
motor gear wheel [0629] 637 idle gear wheel [0630] 641 control
device (CPU) [0631] 647 power switch
* * * * *