U.S. patent application number 13/670611 was filed with the patent office on 2013-07-18 for imaging apparatus.
This patent application is currently assigned to Sony Corporation. The applicant listed for this patent is Sony Corporation. Invention is credited to Hiroshi Kosugi, Eiji Otani, Mitsuru Sato, Shuzo Sato.
Application Number | 20130182169 13/670611 |
Document ID | / |
Family ID | 48313659 |
Filed Date | 2013-07-18 |
United States Patent
Application |
20130182169 |
Kind Code |
A1 |
Kosugi; Hiroshi ; et
al. |
July 18, 2013 |
IMAGING APPARATUS
Abstract
According to an illustrative embodiment an imaging system is
provided. The system includes a lens tube; a first polarizing
filter; and a second polarizing filter; wherein the first
polarizing filter and the second polarizing filter are adjacent
each other, and wherein a polarizing imparted by the first
polarizing filter is different from a polarizing imparted by the
second polarizing filter.
Inventors: |
Kosugi; Hiroshi; (Kanagawa,
JP) ; Sato; Shuzo; (Kanagawa, JP) ; Otani;
Eiji; (Kanagawa, JP) ; Sato; Mitsuru;
(Kanagawa, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Sony Corporation; |
Tokyo |
|
JP |
|
|
Assignee: |
Sony Corporation
Tokyo
JP
|
Family ID: |
48313659 |
Appl. No.: |
13/670611 |
Filed: |
November 7, 2012 |
Current U.S.
Class: |
348/335 ; 348/65;
359/483.01 |
Current CPC
Class: |
G02B 23/2453 20130101;
G02B 23/2415 20130101; H04N 13/207 20180501; H04N 13/257 20180501;
H04N 2005/2255 20130101; H04N 2213/001 20130101; G02B 23/2484
20130101; G02B 27/286 20130101; G06T 3/4015 20130101; A61B 1/04
20130101; G02B 5/201 20130101; A61B 1/00193 20130101; H04N 5/2256
20130101 |
Class at
Publication: |
348/335 ;
359/483.01; 348/65 |
International
Class: |
G02B 23/24 20060101
G02B023/24 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 14, 2011 |
JP |
2011-248694 |
Claims
1. An imaging system comprising: a lens tube; a first polarizing
filter; and a second polarizing filter; wherein the first
polarizing filter and the second polarizing filter are adjacent
each other, and wherein a polarizing imparted by the first
polarizing filter is different from a polarizing imparted by the
second polarizing filter.
2. The imaging system as recited in claim 1, wherein the lens tube
is removable.
3. The imaging system as recited in claim 1, wherein the first
polarizing filter and the second polarizing filter are
removable.
4. The imaging system as recited in claim 1, wherein the first
polarizing filter and the second polarizing filter are arranged in
close proximity to an aperture position of the imaging system.
5. The imaging system as recited in claim 1, further comprising an
imaging unit and an adapter connecting the imaging unit to the lens
tube, and wherein the first polarizing filter and the second
polarizing filter are positioned within the adapter.
6. The imaging system as recited in claim 5, wherein the polarizing
imparted by the first polarizing filter and the polarizing imparted
by the second polarizing filter are linear.
7. The imaging system as recited in claim 6, wherein the polarizing
imparted by the first polarizing filter is orthogonal to the
polarizing imparted by the second polarizing filter.
8. The imaging system as recited in claim 5, wherein the polarizing
imparted by the first polarizing filter and the polarizing imparted
by the second polarizing filter are rotational.
9. The imaging system as recited in claim 8, wherein the polarizing
imparted by the first polarizing filter rotates in a direction
opposite to the polarizing imparted by the second polarizing
filter.
10. The imaging system as recited in claim 5, further comprising an
imaging device that is optically coupled to the lens tube.
11. The imaging system as recited in claim 10, wherein the imaging
device is a solid-state imaging device.
12. The imaging system as recited in claim 10, wherein the imaging
device comprises a plurality of first polarization areas and a
plurality of second polarization areas.
13. The imaging system as recited in claim 12, wherein an
orientation of the plurality of first polarization areas
corresponds to one of the polarizing imparted by the first
polarizing filter and the polarizing imparted by the second
polarizing filter, and an orientation of the plurality of second
polarization areas corresponds to another of the polarizing
imparted by the first polarizing filter and the polarizing imparted
by the second polarizing filter.
14. The imaging system as recited in claim 12, wherein each of the
first polarization areas and each of the second polarization areas
comprises a plurality of wire grid polarizers.
15. The imaging system as recited in claim 5, further comprising an
eyepiece lens positioned within the lens tube.
16. The imaging system as recited in claim 15, further comprising
an imaging device that is optically coupled to the eyepiece
lens.
17. The imaging system as recited in claim 5, wherein the imaging
unit comprises a solid-state imaging device and a casing.
18. The imaging system as recited in claim 5, wherein the system is
an endoscope.
19. The imaging system as recited in claim 5, wherein the system is
a microscope.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] The present application claims priority from Japanese Patent
Application No. JP 2011-248694 filed in the Japanese Patent Office
on Nov. 4, 2011, the entire content of which is hereby incorporated
by reference herein.
BACKGROUND
[0002] The present disclosure relates to an imaging apparatus that
captures an image of a subject as a stereoscopic image.
[0003] In medical practice, for example, an image captured with use
of an endoscope has been displayed on an eyepiece or a monitor
receiver and observed to diagnose an affected part of a body. In
addition, surgery under the use of an endoscope, which is performed
while observing an image displayed on an eyepiece or a monitor
receiver, has been rapidly diffused in recent years. In particular,
the demand for an endoscope apparatus capable of stereoscopically
showing an affected part of a body has increased.
[0004] For example, Japanese Patent Application Laid-open No. Hei
7-20388 (hereinafter, referred to as Patent Document 1) discloses
an endoscope device configured to image a subject at a specified
parallax angle by a stereoscopic imaging unit to obtain video
signals, and independently display two images based on the video
signals on both eyes of a user so that the user can
stereoscopically view the subject.
[0005] In addition, Japanese Patent Application Laid-open No. Hei
10-62697 (hereinafter, referred to as Patent Document 2) discloses
an endoscope device including a lens, a CCD (Charge Coupled
Device), a drum, and a motor. The lens forms an image of an
observed part via a diaphram in an eyepiece. The CCD has an imaging
surface at the image-forming position of the lens. The drum divides
the image of the observed part, which is formed by the lens, into
two of left and right parts and supplies them to the imaging
surface of the CCD. The motor drives the drum to rotate.
SUMMARY
[0006] However, the endoscope device disclosed in Patent Document 1
uses two imaging optical systems including imaging lenses and CCD
cameras, which leads to a problem of an increase in size of the
device. Further, in the endoscope device disclosed in Patent
Document 2, the drum and a rotation-drive system thereof are
incorporated in its imaging optical system, and therefore the
configuration becomes inevitably complicated.
[0007] In view of the circumstances as described above, it is
desirable to provide an imaging apparatus with which a stereoscopic
image of a subject is acquired and that has a simple configuration
without increase in size.
[0008] An imaging system according to an illustrative embodiment
includes a lens tube; a first polarizing filter; and a second
polarizing filter; wherein the first polarizing filter and the
second polarizing filter are adjacent each other, and wherein a
polarizing imparted by the first polarizing filter is different
from a polarizing imparted by the second polarizing filter.
[0009] As described above, according to the present disclosure, a
stereoscopic image of a subject is acquired with an apparatus
having a simple configuration without increase in size.
[0010] These and other objects, features and advantages of the
present disclosure will become more apparent in light of the
following detailed description of best mode embodiments thereof, as
illustrated in the accompanying drawings.
BRIEF DESCRIPTION OF DRAWINGS
[0011] FIG. 1 is a schematic diagram showing a configuration of an
imaging system including an imaging apparatus according to a first
embodiment of the present disclosure;
[0012] FIG. 2 is a schematic cross-sectional diagram showing the
entire configuration of the imaging apparatus;
[0013] FIG. 3A is a schematic diagram showing an example of an
optical system of the imaging apparatus, FIG. 3B is a schematic
front diagram of a polarizing filter incorporated into the imaging
apparatus, and FIG. 3C is a schematic diagram showing a
light-receiving surface of an imaging device incorporated in the
imaging apparatus;
[0014] FIG. 4A is a cross-sectional diagram schematically showing a
configuration of the imaging device, and FIG. 4B is a schematic
diagram showing the light-receiving surface of the imaging
device;
[0015] FIG. 5A and FIG. 5B are conceptual diagrams of light that
reaches the imaging device from a subject, and FIG. 5C and FIG. 5D
are diagrams schematically showing images formed on the imaging
device by the light shown in FIG. 5A and FIG. 5B;
[0016] FIG. 6 is a conceptual diagram for explaining the
light-receiving surface of the imaging device;
[0017] FIG. 7 is a conceptual diagram for explaining the
light-receiving surface of the imaging device;
[0018] FIG. 8 is a schematic cross-sectional diagram showing the
entire configuration of an imaging apparatus according to a second
embodiment of the present disclosure;
[0019] FIG. 9 is a schematic cross-sectional diagram showing the
entire configuration of an imaging apparatus according to a third
embodiment of the present disclosure; and
[0020] FIG. 10A is a diagram showing a modified example of the
configuration shown in FIG. 3B, and FIG. 10B is a diagram showing a
modified example of the configuration shown in FIG. 3C.
DETAILED DESCRIPTION OF EMBODIMENTS
[0021] Hereinafter, embodiments of the present disclosure will be
described with reference to the drawings.
First Embodiment
(Imaging System)
[0022] FIG. 1 is a schematic diagram showing a configuration of an
imaging system including an imaging apparatus according to a first
embodiment of the present disclosure. In this embodiment, an
example in which the imaging apparatus is applied to an endoscope
apparatus used in medical practice will be described.
[0023] An imaging system 1 includes an endoscope apparatus 10, a
control unit 20, and a monitor 30. Hereinafter, the imaging system
1 of this embodiment will be described.
[0024] The endoscope apparatus 10 includes a lens tube 11 and an
imaging unit 12. The lens tube 11 is inserted into a body of a
patient and irradiates an affected part of the body (subject) with
illumination light. The imaging unit 12 receives reflected light,
i.e., a light flux from the affected part of the subject
(hereinafter, referred to as subject light flux), which is
transmitted through the lens tube 11, converts the reflected light
into an electrical signal to generate an image signal, and outputs
the generated image signal to the control unit 20.
[0025] The control unit 20 includes a light source 21 and a signal
processing unit 22. The light source 21 is connected to a light
source connection unit 11a of the lens tube 11 via a light
transmission member 21a such as an optical fiber and introduces
illumination light to the lens tube 11. The signal processing unit
22 controls the light source 21 and processes the image signal
output from the imaging unit 12. The signal processing unit 22
generates a stereoscopic image (three-dimensional image) of the
affected part based on the image signal and outputs the image to
the monitor 30. The monitor includes a display unit (screen) having
a horizontal direction in an X-axis direction and a vertical
direction in a Y-axis direction orthogonal to the X-axis direction.
The monitor 30 displays the stereoscopic image of the affected part
on the display unit.
(Endoscope Apparatus)
[0026] Next, the endoscope apparatus 10 will be described in
detail.
[0027] FIG. 2 is a schematic cross-sectional diagram showing the
entire configuration of the endoscope apparatus 10. The endoscope
apparatus 10 includes the lens tube 11, the imaging unit 12, and an
adapter 13 (connection member).
[0028] The lens tube 11 includes a cylindrical rigid scope 111
having an axial center parallel to a Z-axis direction of FIG. 2,
and an eyepiece 112.
[0029] The rigid scope 111 has a tip end 111a to be inserted into a
body of a patient and a base 111b connected to the eyepiece 112.
The tip end 111a is configured to emit illumination light and
receive reflected light of the illumination light from the subject.
The rigid scope 111 incorporates a light transmission path and an
imaging optical system 111c (FIG. 3A). The illumination light
introduced into the light source connection unit 11a is transmitted
to the tip end 111a through the light transmission path. The
imaging optical system 111c transmits a subject light flux that has
been entered the tip end 111a to the base 111b.
[0030] The eyepiece 112 is used when the affected part of the body
is observed under direct vision. The eyepiece 112 may include an
eyepiece lens therein. In this embodiment, the imaging optical
system 111c is configured such that an aperture position of the
subject light flux corresponds to a position of a pupil of a user
(doctor) who directly views the affected part via the eyepiece
112.
[0031] The imaging unit 12 includes a single-panel imaging device
15 having a light-receiving surface that receives the subject light
flux. The imaging device 15 includes a plurality of pixels arrayed
along the X-axis direction (horizontal direction) and the Y-axis
direction (vertical direction), and is a solid-state imaging device
such as a CCD (Charge Coupled Device) or a CMOS (Complementary
Metal-Oxide Semiconductor). An array of wire grid polarizers is
formed on the light-receiving surface of the imaging device 15, as
described later.
[0032] The imaging unit 12 also includes a casing 120 that
accommodates the imaging device 15, and the like. The casing 120
includes an opening 121 connected to the adapter 13. The imaging
device 15 is arranged within the opening 121.
[0033] The adapter 13 includes a first connection end 131 connected
to the eyepiece 112 of the lends tube 11, a second connection end
132 connected to the opening 121 of the imaging unit 12, and a
hollow portion 133. The adapter 13 functions as a mounter for
connecting the eyepiece 112 of the lens tube 11 to the imaging unit
12. For example, a C-mount adapter is used as the adapter 13.
[0034] The adapter 13 is detachably connected to the eyepiece 112.
Accordingly, a common imaging unit may be used for various types of
lens tubes that are different in length or diameter. In this
embodiment, the adapter 13 includes a holder 134 that is attached
to the first connection end 131 and is capable of engaging with the
eyepiece 112 by an external operation. The second connection end
132 includes a screw portion 13c and is connected to the opening
121 of the imaging unit 12 via the screw portion 13c.
[0035] As shown in FIG. 2, the first connection end 131 of the
adapter 13 includes a concave portion 13a that is capable of
accommodating an end portion of the eyepiece 112. A reference
surface 13b for positioning the eyepiece 112 is formed at the
bottom of the concave portion 13a. The end portion of the eyepiece
112 abuts on the reference surface 13b, thus defining a relative
position of the eyepiece 112 with respect to the adapter 13. The
reference surface 13b is formed to be orthogonal to the Z axis. The
holder 134 is for maintaining a state where the position of the
eyepiece 112 with respect to the concave portion 13a is determined.
The holder 134 is constituted of a plate-like member that is
detachable from the first connection end 131 (concave portion 13a)
in the Y-axis direction of FIG. 2 by an external operation, and
includes an engagement portion v that is engaged with an outer
circumference of the eyepiece 112 when the holder 134 is mounted to
the concave portion 13a.
[0036] The hollow portion 133 is formed so as to penetrate the
adapter 13 in the Z-axis direction and forms a path that guides the
subject light flux emitted from the eyepiece 112 to the imaging
device 15. A polarizing filter 14 and an imaging lens 16 are
arranged in the hollow portion 133.
[0037] The polarizing filter 14 includes two filter sections that
separate the subject light flux projected from the eyepiece 112
into two polarization components. Specifically, the polarizing
filter 14 includes a first filter section 141 and a second filter
section 142 (FIG. 3B). The first filter section 141 allows a first
polarization component of the subject light flux, which oscillates
in the X-axis direction, to pass therethrough and blocks a second
polarization component of the subject light flux, which oscillates
in the Y-axis direction. The second filter section 142 blocks the
first polarization component of the subject light flux and allows
the second polarization component of the subject light flux to pass
therethrough.
[0038] In this embodiment, the polarizing filter 14 is incorporated
in the adapter 13 and disposed at the end portion of the eyepiece
112 so as to be aligned with the reference surface 13b of the first
connection end 131. Accordingly, the polarizing filter 14 is
automatically arranged in the vicinity of the eyepiece 112 when the
adapter 13 is mounted to the eyepiece 112.
[0039] The imaging lens 16 is arranged between the polarizing
filter 14 and the imaging device 15. The imaging lens 16 images the
subject light flux that has passed through the polarizing filter 14
on the light-receiving surface of the imaging device 15.
[0040] FIG. 3A is a schematic diagram showing an example of an
optical system of the endoscope apparatus 10.
[0041] The imaging optical system 111c includes a focus lens for
focusing, a zoom lens for enlarging a subject, and the like, and is
generally configured by combination of a plurality of lenses in
order to correct chromatic aberration and the like. The polarizing
filter 14 is arranged on an optical path of a subject light flux L.
In this embodiment, the polarizing filter 14 is arranged at an
aperture position 14A of the subject light flux L. At the aperture
position, the subject light flux becomes parallel light of light
coming from one point of the subject. Therefore, the polarizing
filter 14 is arranged at the aperture position of the subject light
flux, and the subject light flux of the parallel light is allowed
to enter the polarizing filter 14. As a result, the subject light
flux is properly separated for polarization.
[0042] FIG. 3B is a front diagram of the polarizing filter when
viewed from the Z-axis direction. The polarizing filter 14 includes
the first filter section 141 and the second filter section 142 that
are arranged along the X-axis direction. Specifically, the first
filter section 141 and the second filter section 142 are arranged
side by side in the horizontal direction of the display unit of the
monitor 30. The first filter section 141 polarizes the subject
light flux in the X-axis direction, and the second filter section
142 polarizes the subject light flux in the Y-axis direction.
Therefore, a polarization state of first polarized light L1 that
has passed through the first filter section 141 and that of second
polarized light L2 that has passed through the second filter
section 142 are different from each other.
[0043] FIG. 3C is a schematic diagram showing a light-receiving
surface 150 of the imaging device 15. The light-receiving surface
150 includes a plurality of first polarization areas 151 and second
polarization areas 152 that are alternately arranged along the
Y-axis direction (vertical direction) and extend in the X-axis
direction (horizontal direction). The first polarization areas 151
each allow the first polarized light L1 of the subject light flux,
which oscillates in the X-axis direction, to pass therethrough and
block the second polarized light L2 of the subject light flux,
which oscillates in the Y-axis direction. The second polarization
areas 152 each block the first polarized light L1 of the subject
light flux, which oscillates in the X-axis direction, and allow the
second polarized light L2 of the subject light flux, which
oscillates in the Y-axis direction, to pass therethrough.
Therefore, the first polarized light L1 passes through the first
polarization areas 151 to reach the imaging device 15, and the
second polarized light L2 passes through the second polarization
areas 152 to reach the imaging device 15.
[0044] The imaging device 15 captures an image so as to obtain a
stereoscopic image in which a distance between a barycenter BC1 of
the first filter section 141 and a barycenter BC2 of the second
filter section 142 is set to be a baseline length of binocular
disparity. The imaging unit 12 includes, in addition to the imaging
device 15, for example, an image processing unit 122 and an image
storage unit 123. The image processing unit 122 generates right-eye
image data and left-eye image data based on electrical signals
converted by the imaging device 15 and records the data in the
image storage unit 123. It should be noted that the image
processing unit 122 and the image storage unit 123 may be provided
in the signal processing unit 22 of the control unit 20.
[0045] The outer shape of the polarizing filter 14 is circular. The
first filter section 141 and the second filter section 142 each
have an outer shape of a semicircle that occupies half the area of
the polarizing filter 14. The boundary of the first filter section
141 and the second filter section 142 extends in the Y-axis
direction. The polarizing filter 14 formed by combination of the
two filter sections separates incident light into two different
polarization states.
[0046] As described above, the polarizing filter 14 is constituted
of polarizers that are bilaterally symmetrical and generates, at
two positions bilaterally symmetrical in an upright state of the
endoscope apparatus 10, polarization in linear directions
orthogonal to each other or polarization in rotation directions
opposite to each other. The first filter section 141 is a filter
for polarizing the image of the subject that is assumed to be
viewed by a right eye (light assumed to be received by the right
eye). On the other hand, the second filter section 142 is a filter
for polarizing the image of the subject that is assumed to be
viewed by a left eye (light assumed to be received by the left
eye).
[0047] In FIG. 3B, an orientation of an electric field of the first
polarized light L1 (indicated by an outline arrow) is orthogonal to
an orientation of an electric field of the second polarized light
L2 (indicated by an outline arrow). Here, the orientation of the
electric field of the first polarized light L1 is parallel to the
X-axis direction. Specifically, for example, the first polarized
light L1 mainly has a P wave (TM wave) as a polarization component,
and the second polarized light L2 mainly has an S wave (TE wave) as
a polarization component.
[0048] Additionally, as shown in FIG. 3C, the orientation of the
electric field of the first polarized light L1 and the orientation
of the electric field of the first polarization areas 151
(indicated by outline arrows) are parallel, and the orientation of
the electric field of the second polarized light L2 and the
orientation of the electric field of the second polarization areas
152 (indicated by outline arrows) are parallel. Further, an
extinction ratio of the polarizers is favorably 3 or more, and more
favorably, 10 or more.
[0049] In this embodiment, the outer shape of the polarizing filter
14 is a circle with a radius r of 10 mm. Further, the outer shape
of the first filter section 141 and the second filter section 142
is a semicircle that occupies half the area of the polarizing
filter 14. Therefore, the distance between the barycenter BC1 of
the first filter section 141 and the barycenter BC2 of the second
filter section 142 is [(8r)/(3.pi.)]=8.5 mm.
[0050] The first polarization areas 151 and the second polarization
areas 152 that are arranged on the light-receiving surface 150 of
the imaging device 15 are each constituted of a wire grid
polarizer. FIG. 4A is a cross-sectional diagram schematically
showing a configuration of the imaging device 15, and FIG. 4B is a
front diagram schematically showing an arrayed state of the first
and second polarization areas 151 and 152 when viewed from the
Z-axis direction.
[0051] The imaging device 15 has a structure in which, for example,
a photoelectric conversion element 61 provided on a silicon
semiconductor substrate 60, and thereon, a first planarization film
62, a color filter 63, an on-chip lens 64, a second planarization
film 65, an inorganic insulation underlying layer 66, and wire grid
polarizers 67 are laminated. The wire grid polarizers 67 form the
first polarization areas 151 and the second polarization areas 152.
In FIG. 4B, boundaries between pixels are indicated by solid
lines.
[0052] A plurality of wires 68 that constitute the wire grid
polarizers 67 extend in a direction parallel to the X-axis
direction or the Y-axis direction. Specifically, in wire grid
polarizers 67A that constitute the first polarization area 151,
wires 68A extend in a direction parallel to the Y-axis direction.
In wire grid polarizers 67B that constitute the second polarization
area 152, wires 68B extend in a direction parallel to the X-axis
direction. The direction orthogonal to the direction in which the
wires 68 extend is used as a light transmission axis in the wire
grid polarizers 67.
[0053] In this embodiment, an electrical signal used for obtaining
right-eye image data is generated in the imaging device 15 by the
first polarized light L1 that has passed through the first
polarization areas 151 and reached the imaging device 15. Further,
an electrical signal used for obtaining left-eye image data is
generated in the imaging device 15 by the second polarized light L2
that has passed through the second polarization areas 152 and
reached the imaging device 15. The imaging device 15 outputs those
electrical signals at the same time or alternately in chronological
order. The image processing unit 122 performs image processing on
the output electrical signals (electrical signals for obtaining
right-eye image data and left-eye image data, which have been
output from the imaging device 15), and the resultant data are
recorded in the image storage unit 123 as right-eye image data and
left-eye image data.
[0054] FIGS. 5A and 5B are conceptual diagrams of light that
reaches the imaging device 15 from the subject, and FIGS. 5C and 5D
are schematic diagrams showing images formed on the imaging device
by the light shown in FIGS. 5A and 5B.
[0055] As schematically shown in FIGS. 5A and 5B, it is assumed
that the imaging optical system 111c obtains focus on a rectangular
object A, and a circular object B is located at a position closer
to the imaging optical system 111c than the object A. An image of
the rectangular object A is formed in focus on the imaging device
15. Further, an image of the circular object B is formed out of
focus on the imaging device 15. In the example shown in FIG. 5A, on
the imaging device 15, the image of the object B is formed at a
position separate by a distance (+.DELTA.X) from the right-hand
side of the object A. On the other hand, as shown in the example of
FIG. 5B, on the imaging device 15, the image of the object B is
formed at a position separate by a distance (-.DELTA.X) from the
left-hand side of the object A. Therefore, a distance
(2.times..DELTA.X) is used as information related to a depth of the
object B. In other words, an amount and a direction of blurring of
the object B, which is located closer to the endoscope apparatus
than the object A, are different from those of an object located
farther from the endoscope apparatus, and the amount of blurring of
the object B differs depending on the distance between the object A
and the object B.
[0056] Then, a stereoscopic image is obtained, in which the
distance between the barycentric positions of the shapes of the
first filter section 141 and the second filter section 142 of the
polarizing filter 14 is set to be a baseline length of binocular
disparity. In other words, the stereoscopic image is obtained by a
well-known method, based on a right-eye image (see schematic
diagram of FIG. 5C) and a left-eye image (see schematic diagram of
FIG. 5D) that are obtained as described above. It should be noted
that when right-eye image data is combined with left-eye image
data, a normal two-dimensional (plane) image, which is not a
stereoscopic image, is obtained.
[0057] FIG. 6 is a conceptual diagram for explaining the
light-receiving surface of the imaging device 15.
[0058] The imaging device 15 has a bayer array, in which one pixel
is constituted of four sub-pixels (one red pixel R to receive red
light, one blue pixel B to receive blue light, and two green pixels
G to receive green light). The first polarization area 151 is
arranged for a pixel group in one row arranged along the X-axis
direction. Similarly, the second polarization area 152 is arranged
for a pixel group in one row that is arranged along the X-axis
direction and is adjacent to the former pixel group in the Y-axis
direction. The first polarization areas 151 and the second
polarization areas 152 are alternately arranged in the Y-axis
direction.
[0059] The first polarization areas 151 and the second polarization
areas 152 extend in the X-axis direction as a whole. A unit length
of the first polarization areas 151 and second polarization areas
152 along the X-axis direction and Y-axis direction is equal to a
length of the imaging device 15 along the X-axis direction and the
Y-axis direction. With such a configuration, a band-like image
extending in the X-axis direction based on the light mainly having
a P-wave component (right-eye image) and a band-like image
extending in the X-axis direction based on the light mainly having
an S-wave component (left-eye image) are alternately generated
along the Y-axis direction. In FIG. 6, vertical lines drawn in the
first polarization areas 151 and transverse lines drawn in the
second polarization areas 152 schematically show the wires of the
wire grid polarizers 67A and 67B.
[0060] The electrical signals for each of the right-eye image data
and the left-eye image data are generated along the Y-axis
direction in every other row, as described above. In this regard,
to generate the right-eye image data and the left-eye image data,
the image processing unit 122 performs mosaic processing, e.g.,
super-resolution processing on the electrical signals, to
eventually generate the right-eye image data and the left-eye image
data. Further, the emphasis, optimization, and the like of
disparity are also achieved by, for example, a disparity detection
technique of generating a disparity map by stereo matching based on
the left-eye image data and the right-eye image data, and a
disparity control technique of controlling disparity based on a
disparity map.
[0061] FIG. 7 is a conceptual diagram of the light-receiving
surface with the bayer array, for explaining image processing
(mosaic processing) of performing mosaic processing on electrical
signals obtained from the imaging device to obtain signal values.
FIG. 7 shows an example in which a signal value on a green pixel in
the left-eye image is generated.
[0062] In normal demosaic processing, it is general to use a mean
value of electrical signals of adjacent pixels of a single color.
However, as in this embodiment, in the case where a pixel group
(pixel row) for obtaining the right-eye image data and a pixel
group (pixel row) for obtaining the left-eye image data are
alternately repeated, there is a fear that original image data is
not obtained when the values of adjacent pixels are used as they
are. In this regard, demosaic processing is performed in
consideration of whether an electrical signal of a pixel to be
referred to corresponds to the right-eye image data or the left-eye
image data.
[0063] It is assumed that in the bayer array, a red pixel R is
arranged at a position (4,2). In this case, to generate a
green-pixel signal value g' corresponding to the position (4,2), a
calculation represented by the following expression is
performed.
g'4,2=(g4,1+g4,3+g5,2+g1,2.times.W3)/(3.0+W3)
[0064] In the expression, g'i,j on the left side is a green-pixel
signal value at a position (i,j). Further, gi,j on the right side
is an electrical signal value of a green pixel at the position
(i,j). Furthermore, "3.0" corresponds to the sum of weights.
Specifically, the weights are obtained when a distance (W1) from
the pixel of interest R4,2 to each of adjacent pixels G4,1, G4,3,
and G5,2 is set to, for example, "1.0" and reciprocals thereof are
set as the weights. W3 is a weight for an electrical signal value
of a pixel G1,2 that is distant by three pixels and is "1/3" in
this case. When the above expression is generalized, the following
expressions are obtained.
[0065] In the case where i is an even number (signal value of green
pixel G corresponding to position of red pixel R,
g'i,j=(gi,j-1.times.W1+gi,j+1.times.W1+gi+1, j.times.W1+gi-3,
j.times.W3)/(W1.times.3.0+W3).
[0066] In the case where i is an odd number (signal value of green
pixel G corresponding to position of blue pixel B),
g'i,j=(gi,j-1.times.W1+gi,j+1.times.W1+gi-1, j.times.W1+gi+3,
j.times.W3)/(W1.times.3.0+W3) where W1=1.0 and W3=1/3.
[0067] The mosaic processing may also be performed on the red pixel
R and the blue pixel B by the similar manner.
[0068] Pixel signal values at respective pixel positions are
obtained by the demosaic processing, but in this stage, the signal
values are arranged in every other row. Therefore, pixel signal
values are to be generated for areas where pixel signal values are
not provided, by interpolation (complement method). As
interpolation techniques, a well-known method such as a method of
using a mean value of values of adjacent pixels is used. This
interpolation processing may be performed concurrently with the
demosaic processing. The image quality is completely maintained in
the X-axis direction, and accordingly the degradation in image
quality, such as a reduction in resolution of the entire image,
occurs relatively less frequently.
[0069] According to this embodiment, two different images divided
in the horizontal direction by the polarizing filter are
simultaneously generated, and accordingly a stereoscopic image of
an affected part of a body is acquired by one eye. Further, a
compact endoscope apparatus 10 having a simple configuration and
structure and a reduced number of components is provided.
Furthermore, a plurality of sets of lenses and polarizing filters
are unnecessary, and accordingly a displacement and a difference
are not caused in zoom, aperture portion, focus, angle of
convergence, and the like. In addition, since a baseline length of
binocular disparity is relatively short, a natural stereoscopic
effect is obtained. Additionally, when the polarizing filter 14 is
configured to be detachable from the adapter 13, a two-dimensional
image and a three-dimensional image are easily obtained.
Second Embodiment
[0070] FIG. 8 is a schematic cross-sectional diagram showing the
entire configuration of an endoscope apparatus according to a
second embodiment of the present disclosure. Hereinafter, a
configuration different from that of the first embodiment will
mainly be described, and the same components as those of the first
embodiment will be denoted by the same reference symbols and the
description thereof will be omitted or simplified.
[0071] An endoscope apparatus 200 of this embodiment is different
from the endoscope apparatus 10 of the first embodiment described
above in that a polarizing filter 24 is arranged within the rigid
scope 111 of the lens tube 11. The polarizing filter 24 has the
same configuration as that of the polarizing filter 14 described in
the first embodiment and is arranged in an aperture portion (not
shown) of a subject light flux in an imaging optical system within
the rigid scope 111. The aperture portion has a function of
increasing or decreasing an amount of light in order to adjust the
amount of condensed light and is constituted by, for example,
combination of a plurality of plate-like blades.
[0072] The polarizing filter 24 is arranged in the vicinity of the
aperture portion. The polarizing filter 24 is arranged at a
position as close as possible to the aperture portion as long as it
does not interfere with the action of the aperture portion. With
this configuration, the subject light flux of parallel light is
allowed to enter the polarizing filter 24, with the result that the
subject light flux is properly separated for polarization.
[0073] Also in the endoscope apparatus 200 configured as described
above according to this embodiment, the same action and effect as
those of the first embodiment described above are obtained.
Third Embodiment
[0074] FIG. 9 is a schematic cross-sectional diagram showing the
entire configuration of an endoscope apparatus according to a third
embodiment of the present disclosure. Hereinafter, a configuration
different from that of the first embodiment will mainly be
described, and the same components as those of the first embodiment
will be denoted by the same reference symbols and the description
thereof will be omitted or simplified.
[0075] An endoscope apparatus 300 of this embodiment is different
from the endoscope apparatus 10 of the first embodiment described
above in that a polarizing filter 34 is arranged within the casing
120 of the imaging unit 12. The polarizing filter 34 has the same
configuration as that of the polarizing filter 14 described in the
first embodiment and is arranged in an aperture portion (not shown)
of a subject light flux in an imaging optical system within the
casing 120. An optical component having the aperture function
described above may be arranged at the aperture portion.
[0076] In this embodiment, the imaging lens 16 is arranged between
the polarizing filter 34 and the imaging device 15. An optical lens
17 to project the subject light flux emitted from the eyepiece 112
to the polarizing filter 34 is arranged within the adapter 13.
[0077] Also in the endoscope apparatus 300 configured as described
above according to this embodiment, the same action and effect as
those of the first embodiment described above are obtained.
[0078] Hereinabove, the embodiments of the present disclosure have
been described, but the present disclosure is not limited to the
embodiments described above. The present disclosure can be
variously modified as a matter of course without departing from the
gist of the present disclosure.
[0079] For example, in the embodiments described above, each of the
imaging apparatuses according to the embodiments of the present
disclosure is applied to an endoscope apparatus used in medical
practice has been described as an example. However, the present
disclosure is not limited to the above example and is applicable
to, for example, a microscope, an endoscope for industrial use, and
the like.
[0080] Further, in the embodiments described above, the polarizing
filter 14 is configured such that the orientation of the electric
field of the first polarized light L1 is parallel to the X-axis
direction, and the orientation of the electric field of the second
polarized light L2 is parallel to the Y-axis direction. Instead,
the polarizing filter may be configured such that the orientations
of the respective electric fields of the first polarized light and
the second polarized light form an angle of 45 degrees with respect
to the X-axis direction and the Y-axis direction.
[0081] FIG. 10A is a schematic diagram of a polarizing filter 44
configured as described above. A first filter section 441 and a
second filter section 442 form first polarized light and second
polarized light, respectively, each having an electric-field
direction in a direction indicated by an outline arrow. Those first
polarized light and second polarized light are composed of
polarization components orthogonal to each other. In this case, a
light-receiving surface of an imaging device 45 is provided with
polarization areas as shown in FIG. 10B. A light transmission axis
of first polarization areas 451 is parallel to the electric-field
direction of the first polarized light, and a light transmission
axis of second polarization areas 452 is parallel to the
electric-field direction of the second polarized light. Those first
polarization areas 451 and second polarization areas 452 are
constituted of wire grid polarizers having the configuration as
described above. Also in the configuration as described above, the
same action and effect as those of the embodiments described above
are obtained.
[0082] It should be noted that the present disclosure may be
configured as follows.
[0083] (1) An imaging system including:
[0084] a lens tube;
[0085] a first polarizing filter; and
[0086] a second polarizing filter;
[0087] wherein the first polarizing filter and the second
polarizing filter are adjacent each other, and wherein a polarizing
imparted by the first polarizing filter is different from a
polarizing imparted by the second polarizing filter.
[0088] (2) The imaging system according to (1), wherein the lens
tube is removable.
[0089] (3) The imaging system according to (1), wherein the first
polarizing filter and the second polarizing filter are
removable.
[0090] (4) The imaging system according to (1), wherein the first
polarizing filter and the second polarizing filter are arranged in
close proximity to an aperture position of the imaging system.
[0091] (5) The imaging system according to (1), further including
an imaging unit and an adapter connecting the imaging unit to the
lens tube, and wherein the first polarizing filter and the second
polarizing filter are positioned within the adapter.
[0092] (6) The imaging system according to (5), wherein the
polarizing imparted by the first polarizing filter and the
polarizing imparted by the second polarizing filter are linear.
[0093] (7) The imaging system according to (6), wherein the
polarizing imparted by the first polarizing filter is orthogonal to
the polarizing imparted by the second polarizing filter.
[0094] (8) The imaging system according to (5), wherein the
polarizing imparted by the first polarizing filter and the
polarizing imparted by the second polarizing filter are
rotational.
[0095] (9) The imaging system according to (8), wherein the
polarizing imparted by the first polarizing filter rotates in a
direction opposite to the polarizing imparted by the second
polarizing filter.
[0096] (10) The imaging system according to (5), further including
an imaging device that is optically coupled to the lens tube.
[0097] (11) The imaging system according to (10), wherein the
imaging device is a solid-state imaging device.
[0098] (12) The imaging system according to (10), wherein the
imaging device includes a plurality of first polarization areas and
a plurality of second polarization areas.
[0099] (13) The imaging system according to (12), wherein an
orientation of the plurality of first polarization areas
corresponds to one of the polarizing imparted by the first
polarizing filter and the polarizing imparted by the second
polarizing filter, and an orientation of the plurality of second
polarization areas corresponds to another of the polarizing
imparted by the first polarizing filter and the polarizing imparted
by the second polarizing filter.
[0100] (14) The imaging system according to (12), wherein each of
the first polarization areas and each of the second polarization
areas includes a plurality of wire grid polarizers.
[0101] (15) The imaging system according to (5), further including
an eyepiece lens positioned within the lens tube.
[0102] (16) The imaging system according to (15), further including
an imaging device that is optically coupled to the eyepiece
lens.
[0103] (17) The imaging system according to (5), wherein the
imaging unit includes a solid-state imaging device and a
casing.
[0104] (18) The imaging system according to (5), wherein the system
is an endoscope.
[0105] (19) The imaging system according to (5), wherein the system
is a microscope.
[0106] (20) The imaging system according to (1), wherein the first
polarizing filter and the second polarizing filter are positioned
within the lens tube.
[0107] (21) The imaging system according to (1), further including
an imaging unit that is optically coupled to the lens tube, and
wherein the first polarizing filter and the second polarizing
filter are positioned within the imaging unit.
[0108] (22) The imaging system according to (21), wherein the
imaging unit includes a solid-state imaging device and a
casing.
[0109] (23) An imaging method including;
[0110] providing a lens tube; and
[0111] polarizing light within the lens tube using at least a first
polarizing filter and a second polarizing filter, the first
polarizing filter and the second polarizing filter being adjacent
each other, and a polarizing imparted by the first polarizing
filter being different from a polarizing imparted by the second
polarizing filter.
[0112] (24) A non-transitory computer-readable medium having stored
thereon a computer-readable program for implementing an imaging
method, the method including:
[0113] providing a lens tube; and
[0114] polarizing light within the lens tube using at least a first
polarizing filter and a second polarizing filter, the first
polarizing filter and the second polarizing filter being adjacent
each other, and a polarizing imparted by the first polarizing
filter being different from a polarizing imparted by the second
polarizing filter.
[0115] The present disclosure may also be configured as
follows.
[0116] (1) An imaging apparatus, including:
[0117] a lens tube including an eyepiece and configured to transmit
a subject light flux;
[0118] a polarizing filter arranged on an optical path of the
subject light flux and including [0119] a first filter section
configured to allow a first polarization component of the subject
light flux to pass therethrough, and block a second polarization
component of the subject light flux, the first polarization
component oscillating in a first direction, the second polarization
component oscillating in a second direction orthogonal to the first
direction, and [0120] a second filter section configured to block
the first polarization component of the subject light flux and
allow the second polarization component of the subject light flux
to pass therethrough; and
[0121] an imaging unit connected to the eyepiece and including an
imaging device to receive the first polarization component and the
second polarization component.
[0122] (2) The imaging apparatus according to (1), in which
[0123] the polarizing filter is arranged at an aperture position on
the optical path.
[0124] (3) The imaging apparatus according to (1) or (2), in
which
[0125] the polarizing filter is arranged in the eyepiece.
[0126] (4) The imaging apparatus according to any one of (1) to
(3), further including
[0127] a connection member configured to connect the eyepiece and
the imaging unit with each other, wherein
[0128] the polarizing filter is incorporated in the connection
member.
[0129] (5) The imaging apparatus according to (4), in which
[0130] the connection member is detachable from the eyepiece.
[0131] (6) The imaging apparatus according to (4) or (5), in
which
[0132] the polarizing filter is detachable from the connection
member.
[0133] (7) The imaging apparatus according to any one of (1) to
(6), in which
[0134] the imaging device includes a light-receiving surface on
which a plurality of first polarizers and a plurality of second
polarizers are arranged in matrix, the plurality of first
polarizers being configured to allow the first polarization
component to pass therethrough and block the second polarization
component, the plurality of second polarizers being configured to
block the first polarization component and allow the second
polarization component to pass therethrough.
[0135] (8) The imaging apparatus according to (5), in which
[0136] the connection member includes a holder capable of engaging
with the eyepiece by an external operation.
[0137] It should be understood by those skilled in the art that
various modifications, combinations, sub-combinations and
alterations may occur depending on design requirements and other
factors insofar as they are within the scope of the appended claims
or the equivalents thereof.
* * * * *