U.S. patent number RE35,076 [Application Number 07/780,642] was granted by the patent office on 1995-10-31 for endoscope apparatus for displaying images below the mucous membrance.
This patent grant is currently assigned to Olympus Optical Co., Ltd.. Invention is credited to Kazunari Nakamura.
United States Patent |
RE35,076 |
Nakamura |
October 31, 1995 |
Endoscope apparatus for displaying images below the mucous
membrance
Abstract
An endoscope whereby the vein image below the mucous membrane
within a body cavity or the like can be observed has an insertable
part to be inserted into the body cavity and is provided with an
illuminating window and observing window in the tip part of the
insertable part. A light guide transmitting an illuminating light
emitted from a light source is inserted through the insertable
part. The illuminating light transmitted through the light guide is
emitted from the illuminating window to illuminate an object to be
observed. The reflected light from the object forms an image in an
imaging apparatus through the observing window and the formed
object is converted to an electric signal. A light separating
filter separating the light entering the imaging apparatus into a
plurality of wavelength bands is provided between the light source
part and imaging apparatus. The output signal of the imaging
apparatus is processed by a video signal processing circuit and is
input into an operating circuit. This operating circuit operates
the video signals relating to at least two wavelength bands which
are output signals of the video signal processing circuit and
outputs the result. The output of the operating circuit is
delivered to a picture image displaying monitor.
Inventors: |
Nakamura; Kazunari (Hachioji,
JP) |
Assignee: |
Olympus Optical Co., Ltd.
(Tokyo, JP)
|
Family
ID: |
26938524 |
Appl.
No.: |
07/780,642 |
Filed: |
October 18, 1991 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
Reissue of: |
247194 |
Sep 21, 1988 |
04945409 |
Jul 31, 1990 |
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Current U.S.
Class: |
348/70;
348/162 |
Current CPC
Class: |
A61B
1/0638 (20130101); H04N 5/2256 (20130101); H04N
7/18 (20130101); A61B 1/00009 (20130101); A61B
1/0646 (20130101); H04N 2005/2255 (20130101) |
Current International
Class: |
A61B
1/04 (20060101); H04N 5/225 (20060101); H04N
7/18 (20060101); H04N 007/18 (); H04N 005/335 ();
A61G 001/06 () |
Field of
Search: |
;358/98,110 ;128/6,4
;348/70,162 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Peng; John K.
Assistant Examiner: Lefkowitz; Edward
Attorney, Agent or Firm: Armstrong, Westerman, Hattori,
McLeland & Naughton
Claims
What is claimed is:
1. An endoscope apparatus comprising:
an elongated insertable part having an illuminating window and
observing window in a tip part;
a light source part emitting an illuminating light;
a light guide means, inserted through said insertable part, for
transmitting said illuminating light and for illuminating an object
from said illuminating window;
an imaging means for receiving .[.the.]. reflected light from said
object through said observing window and for converting said
reflected light to an electric signal;
a light separating means interposed in an optical path of said
illuminating light between said light source part and imaging
means, for separating the light entering said imaging means into a
plurality of wavelength bands, said light includes at least a range
other than a visible range;
a video signal processing means for processing the .[.output.].
.Iadd.electric .Iaddend.signal of said imaging means to produce a
.[.video signal.]. .Iadd.plurality of video signals.Iaddend.;
an operating means for removing video information included in one
video signal by operating on at least two of a plurality of video
signals based on light of said plurality of wavelength bands
separated by said light separating means which are output signals
of said video signal processing means;
a changing means for selecting at least one of the video image
information output by said operating means and a video signal and
for composing a usual color observing picture image output from
said signal processing means; and
a monitor means for displaying a picture image from input signals
selected by said changing means.
2. An endoscope apparatus according to claim 1 wherein said
operating means is a subtracting means detecting the signal
difference between at least two video signals among the video
signals corresponding to different wavelength bands.
3. An endoscope apparatus according to claim 1 wherein said
operating means is a dividing means dividing at least two video
signals among the video signals corresponding to different
wavelength bands.
4. An endoscope apparatus according to claim 2 wherein said light
separating means is formed of wavelength band transmitting filters
transmitting respective wavelength bands of infrared rays, red,
green, blue and ultraviolet rays and is interposed in time series
in the optical path of the illuminating light between said light
source part and light guide means.
5. An endoscope apparatus according to claim 2 wherein said light
separating means is formed of wavelength band transmitting filters
transmitting respective wavelength bands of red including infrared
rays, green and blue including ultraviolet rays and is interposed
in time series in the optical path of the illuminating light
between said light source part and light guide means and an
infrared ray removing filter not transmitting infrared rays and
selectively interposed also in the optical path of the illuminating
light between said light source part and light guide means.
6. An endoscope apparatus according to claim 2 wherein said light
separating means comprises an infrared ray and ultraviolet ray
removing filter not transmitting the wavelength bands of
ultraviolet rays and infrared rays and selectively interposed in
the optical path of the illuminating light between said light
source part and light guide means and a color separating filter
fixedly interposed between said object and imaging means and having
transmitting parts transmitting the respective wavelength band of
yellow including infrared rays, green and cyanine including
ultraviolet rays arranged in the form of a mosaic.
7. An endoscope apparatus having as light separating means
according to claim 4 or 5 wherein said subtracting means has a
plurality of storing parts memorizing the video signals of the
illuminating light having passed through the respective wavelength
band transmitting filters and detects a signal difference of the
video signals stored in said plurality of memorizing parts.
8. An endoscope apparatus having a light separating means according
to claim 6 wherein said subtracting means detects a signal
difference between two color signals output from a color separating
part color-separating the electric signal from the imaging
means.
9. An endoscope apparatus having a color separating means according
to claim 4 wherein said subtracting means according to claim 4
wherein said subtracting means is controlled by said changing means
to one of either making a subtraction to an input signal and
outputting the input signal as is without being subtracted.
10. An endoscope apparatus having a light separating means
according to claim 5 wherein said subtracting means is controlled
by said changing means to one of either making a subtraction to an
input signal and outputting an input signal as is without being
subtracted.
11. An endoscope apparatus having a light separating means
according to claim 6 wherein said changing means has input thereto
a a) difference of a signal detected by said subtracting means and
b) a video signal by a visible light produced from a color signal,
and outputs either of c) the difference of the signal and d) the
video signal by the visible light to said monitor means.
12. An endoscope apparatus according to claim 10 wherein said
changing means will pull said infrared ray removing filter out from
between said light source part and light guide means when detecting
a signal difference and will interpose said infrared ray removing
filter between said light source part and light guide means when
subtraction is not made.
13. An endoscope apparatus according to claim 11 wherein said
changing means will pull said infrared ray and ultraviolet ray
removing filter out from between said light source part and light
guide means when outputting a signal difference and will interpose
said infrared ray and ultraviolet ray removing filter between said
light source part and light guide means when outputting a video
signal by a visible light.
14. An endoscope apparatus according to claim 3 wherein said light
separating means is formed of a wavelength band transmitting filter
transmitting respective wavelength bands of infrared, red, green,
blue and ultraviolet rays and interposed in time series in the
optical path of the illuminating light between the light source
part and light guide means.
15. An endoscope apparatus having a light separating means
according to claim 14 wherein said dividing means has a plurality
of storing parts memorizing the video signals of the illuminating
light having passed through the respective wavelength band
transmitting filters and detects the signal difference between the
video signals stored in the plurality of memorizing parts.
16. An endoscope apparatus having a light separating means
according to claim 14, wherein said dividing means is controlled by
said changing means to one of either dividing the input signal and
outputting the input signal as is without being divided. .Iadd.17.
An endoscope apparatus comprising:
an elongated insertable part having an illuminating window and
observing window in a tip part;
a light source part emitting an illuminating light;
a light guide means, inserted through said insertable part, for
transmitting said illuminating light and for illuminating an object
from said illuminating window;
an imaging means for receiving reflected light from said object
through said observing window and for converting said reflected
light to an electric signal;
a light separating means interposed in an optical path of said
illuminating light between said light source part and imaging
means, for separating the light entering said imaging means into a
plurality of wavelength bands;
a video signal processing means for processing the electric signal
of said imaging means to produce a plurality of video signals;
an operating means for removing video information included in one
video signal by operating on at least two of a plurality of video
signals based on light of said plurality of wavelength bands
separated by said light separating means which are output signals
of said video signal processing means;
a changing means for selecting at least one of the video image
information output by said operating means and a video signal and
for composing a usual color observing picture image output from
said signal processing means; and
a monitor means for displaying a picture image from input signals
selected
by said changing means. .Iaddend. .Iadd.18. An endoscope apparatus
according to claim 17 wherein said operating means is a subtracting
means detecting the signal difference between at least two video
signals among the video signals corresponding to different
wavelength bands. .Iaddend. .Iadd.19. An endoscope apparatus
according to claim 17 wherein said operating means is a dividing
means dividing at least two video signals among the video signals
corresponding to different wavelength bands. .Iaddend. .Iadd.20. An
endoscope apparatus according to claim 18 wherein said light
separating means is formed of wavelength band transmitting filters
transmitting respective wavelength bands of infrared rays, red,
green, blue and ultraviolet rays and is interposed in time series
in the optical path of the illuminating light between said light
source part and light guide means. .Iaddend. .Iadd.21. An endoscope
apparatus according to claim 18 wherein said light separating means
is formed of wavelength band transmitting filters transmitting
respective wavelength bands of red including infrared rays, green
and blue including ultraviolet rays and is interposed in time
series in the optical path of the illuminating light between said
light source part and light guide means and an infrared ray
removing filter not transmitting infrared rays and selectively
interposed also in the optical path of the illuminating light
between said light source part and light guide means. .Iaddend.
.Iadd.22. An endoscope apparatus according to claim 18 wherein said
light separating means comprises an infrared ray and ultraviolet
ray removing filter not transmitting the wavelength bands of
ultraviolet rays and infrared rays and selectively interposed in
the optical path of the illuminating light between said light
source part and light guide means and a color separating filter
fixedly interposed between said object and imaging means and having
transmitting parts transmitting the respective wavelength bands of
yellow including infrared rays, green and cyanine including
ultraviolet rays arranged in the form of a mosaic. .Iaddend.
.Iadd.23. An endoscope apparatus having a light separating means
according to claim 20 and 21 wherein said subtracting means has a
plurality of memorizing parts storing the video signals of the
illuminating light having passed through the respective wavelength
band transmitting filters and detects a signal difference of the
video signals stored in said plurality of memorizing parts.
.Iaddend. .Iadd.24. An endoscope apparatus having a light
separating means according to claim 22 wherein said subtracting
means detects a signal difference between two color signals output
from a color separating part color-separating the electric signal
from the imaging
means. .Iaddend. .Iadd.25. An endoscope apparatus having a color
separating means according to claim 20 wherein said subtracting
means is controlled by said changing means to one of either making
a subtraction to an input signal and outputting the input signal as
is without being subtracted. .Iaddend. .Iadd.26. An endoscope
apparatus having a light separating means according to claim 21
wherein said subtracting means is controlled by said changing means
to one of either making a subtraction to an input signal and
outputting an input signal as is without being subtracted.
.Iaddend. .Iadd.27. An endoscope apparatus having a light
separating means according to claim 22 wherein said changing means
has input thereto a) a difference of a signal detected by said
subtracting means and b) a video signal by a visible light produced
from a color signal, and outputs either of c) the difference of the
signal and d) the video signal by the visible light to said monitor
means. .Iaddend. .Iadd.28. An endoscope apparatus according to
claim 25 wherein said changing means will pull said infrared ray
removing filter out from between said light source part and light
guide means when detecting a signal difference and will interpose
said infrared ray removing filter between said light source part
and light guide means when subtracting is
not made. .Iaddend. .Iadd.29. An endoscope apparatus according to
claim 27 wherein said changing means will pull said infrared ray
and ultraviolet ray removing filter out from between said light
source part and light guide means when outputting a signal
difference and will interpose said infrared ray and ultraviolet ray
removing filter between said light source part and light guide
means when outputting a video signal by a visible light. .Iaddend.
.Iadd.30. An endoscope apparatus according to claim 19 wherein said
light separating means is formed of a wavelength band transmitting
filter transmitting respective wavelength bands of infrared, red,
green, blue and ultraviolet rays and interposed in time series in
the optical path of the illuminating light between the light source
part and light guide means. .Iaddend. .Iadd.31. An endoscope
apparatus having a light separating means according to claim 30
wherein said dividing means has a plurality of memorizing parts
storing the video signals of the illuminating light having passed
through the respective wavelength band transmitting filters and
detects the signal difference between the video signals stored in
the plurality of memorizing parts. .Iaddend. .Iadd.32. An endoscope
apparatus having a light separating means according to claim 30
wherein said dividing means is controlled by said changing means to
be one of either dividing the input signal and outputting the input
signal as is without being divided. .Iaddend.
Description
BACKGOUND OF THE INVENTION:
This invention relates to an endoscope apparatus whereby the vein
image or the like below the mucous membrane within a body cavity or
the like can be observed.
Recently, various electronic endoscopes (also called electronic
scopes) wherein a solid state imaging device such as a charge
coupled device is used as an imaging means, have been
suggested.
Such an electronic endoscope has advantages because the resolution
is higher than in a fiber scope, it is easy to record and reproduce
picture images and picture image processes such as enlargement and
comparison of two picture images are easy.
Now, when distinguishing the affected part and normal part from
each other by observing the observed part with the above mentioned
electronic endoscope, it will be necessary to sense (recognize) a
delicate tone difference.
However, when the variation of the tone of the observed part is
delicate, in order to detect this delicate difference, a lot of
knowledge and experience will be required and further a long time
will be required until it is sensed. Even if attention is
concentrated during the sensing, it has been difficult to always
make a proper determination.
In order to cope with such circumstances, for example, in the
publication of a Japanese patent application of a Japanese patent
application laid open No. 3033/1981, there is disclosed a technique
wherein, by noting that, in a range other than the visible range
as, for example, an infrared wavelength range, some variation of
the tone will be large, a spectral light having at least one
infrared wavelength range is led in time series to illuminate an
object to be observed. The reflected light from the observed object
is made to form an image on a solid state imaging device. The image
is converted to an electric signal and the electric signal is
processed in response to the wavelength range so that a picture
image in the wavelength range may be displayed by a specific color
signal.
Generally, in an electronic endoscope, a solid state imaging device
is photosensitive even to an infrared wavelength range and
therefore the image information of the infrared wavelength range
can be detected. However, when coloring the image, the image
information of the infrared wavelength range will be in the way of
balancing the colors. Therefore, in order to elevate the fidelity
of the colors, usually, the illuminating light of the infrared
wavelength range is prevented by an infrared ray cutting filter or
the like from being radiated to the observed object or will be
prevented by a provided filter from reaching the light receiving
surface of the solid state imaging device even if it is
radiated.
According to this prior art example, by using the feature that the
light in the infrared range is higher in the penetration degree
into a living body or the like than in the visible light range, the
observation and recording of an image below the mucous membrane
such as the part observed in the infrared range which have been
difficult with the observation of the observed part in the visible
light range are made possible. This enables, for example, the vein
running state below the mucous membrane of an organ to be
accurately observed and becomes a help in determining the affected
part or the like.
However, in the above mentioned prior art example, for example, an
image of a thick vein near the mucous membrane surface can be
sensed in the observed part but, as the illuminating light is
reflected on the mucous membrane surface in this observed part, the
resolution of the image below the mucous membrane will not rise and
it has been difficult to sense the information over the details
below the mucous membrane.
OBJECT AND SUMMARY OF THE INVENTION:
An object of the present invention is to provide an endoscope
whereby the running state of minute veins below the mucous membrane
and an affect part can be observed at a high resolution by removing
the reflected light on the mucous membrane surface in the observed
part.
The above mentioned object is attained by providing an endoscope
including a light separating device and operating device. The
endoscope has a light separating device separating an illuminating
light into a plurality of wavelength bands between a light source
part emitting the illuminating light and an imaging device
electrically converting an object image. The output signal of the
imaging device will be processed to be a video signal by a video
signal processing device and will be input into an operating means.
The operating device will operate at least two video signals among
the video signals output from the video signal processing device
and corresponding to different wavelength bands to take out and
output the video information of the other included in the video
information corresponding to one video signal. The output of the
operating device will be delivered to a monitor displaying the
picture image.
BRIEF DESCRIPTION OF THE DRAWING:
FIGS. 1 to 4 relate to the first embodiment of the present
invention.
FIG. 1 is an explanatory view showing an entire endoscope imaging
apparatus.
FIG. 2 is an elevation of a rotary filter provided with five
wavelength range transmitting filters.
FIG. 3 is an explanatory diagram showing the transmitting
characteristics of the five wavelength range transmitting filters
in the rotary filter.
FIG. 4 is an explanatory diagram showing the characteristics of
absorbing hemoglobin in a blood by illuminating light of respective
wavelengths.
FIGS. 5 to 7 relate to the second embodiment of the present
invention.
FIG. 5 is an explanatory diagram showing the formation of an entire
endoscope imaging apparatus.
FIG. 6 is an elevation of a rotary filter provided with three
wavelength range transmitting filters.
FIG. 7 is an explanatory diagram showing the transmitting
characteristics of the three wavelength range transmitting filters
in the rotary filter.
FIGS. 8 to 10 relate to the third embodiment of the present
invention.
FIG. 8 is an explanatory diagram showing the formation of an entire
endoscope imaging apparatus.
FIG. 9 is an explanatory view showing an array of color filters
placed in front of a solid state imaging device.
FIG. 10 is an explanatory diagram showing the spectral output
characteristics of the solid state imaging device.
FIG. 11 relates to the fourth embodiment of the present invention
and is an explanatory view showing the formation of an endoscope
imaging apparatus having a dividing circuit.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS:
FIGS. 1 to 4 show the first embodiment of the present
invention.
In this embodiment, the present invention is applied to an
electronic endoscope imaging apparatus in which a frame sequential
system is adopted.
As shown in FIG. 1, an endoscope 2 fitted to an endoscope imaging
apparatus 1 comprises an elongated flexible insertable part 3 and
an operating part (not illustrated) provided in the rear of the
insertable part 3. A light guide 4 leading an illuminating light is
inserted through the insertable part 3 and operating part (not
illustrated) of the above mentioned endoscope 2. An observing
optical system 5 consisting of an objective lens or the like
receiving an observed image light obtained when an illuminating
light is radiated to an observed part is arranged in the tip part
of the above mentioned insertable part 3. A solid state imaging
device 6 consisting of a charge coupled device (CCD) or the like is
arranged in the position where the observed image light is made to
form an image by this observing optical system. This solid state
imaging device is connected into the later described endoscope
imaging apparatus 1 through signal lines 7a and 7b.
Further, the endoscope imaging apparatus 1 is connected to a
television monitor 8 so that the observed part image may be output
as a video image.
The endoscope imaging apparatus 1 is formed of a light source part
9 wherein an illuminating light adapted to a frame sequential
system is obtained, a control part 10 processing the video signal
and detecting the signal difference and others described later.
The above mentioned light source part 9 is provided with a lamp 11
emitting an illuminating light having a wavelength in an
ultraviolet light range to a visible light range and further to an
infrared range and a lamp power source circuit 12 feeding an
electric power to this lamp 11 and having the exposure adjusted by
a later described level sensing circuit 20.
In such a case, for example, a xenon lamp, halogen lamp or
strobolamp will be used for the lamp 11.
The above mentioned light source part 9 has a motor driving circuit
13 controlled by a synchronous signal generating circuit 25, a
motor 14 connected to this motor driving circuit 13 and a rotary
filter 16 provided on the rotary shaft of this motor 14 and
interposed in an optical axis 15 connecting the above mentioned
lamp 11 with the above mentioned light guide 4 on the entrance end
surface.
As shown in FIG. 2, the above mentioned rotary filter 16 has a
wavelength range transmitting filter 17a transmitting a wavelength
range of red (R), a wavelength range transmitting filter 17b
transmitting a wavelength range of green (G), a wavelength range
transmitting filter 17c transmitting a wavelength range of blue
(B), a wavelength range transmitting fiber 17a transmitting a
wavelength range of infrared (IR) and a wavelength range
transmitting filter 17e transmitting a wavelength range of
ultraviolet (UV) arranged in the peripheral direction.
Now, the CCD driving circuit 18 controlled by the above mentioned
synchronous signal generating circuit 25 is connected through a
signal line 7a with the solid state imaging device 6 arranged on
the tip side of the above mentioned insertable part. The above
mentioned solid state imaging device 6 is connected through a
signal line 7b to a pre-amplifying circuit 19 amplifying the
electric signal photoelectrically converted from the observed image
light by this solid state imaging device.
The above mentioned pre-amplifying circuit 19 is connected to a
level sensing circuit 20 which determines the strength of the
photoelectric signal including the picture image information
amplified by the above mentioned pre-amplifying circuit 19. This
level sensing circuit 20 is connected to the above mentioned lamp
power source circuit 20 to control it.
Further, the above mentioned level sensing circuit 20 is to be
connected to the control part 10 processing a video image and
sensing a signal difference.
The above mentioned control part 10 is provided with a video signal
processing circuit 21 controlled by the synchronous signal
generating circuit 25, connected to the above mentioned level
sensing circuit 20 and processing a video signal and an A/D
converting circuit 22 connected to this video signal processing
circuit 21, controlled the same by the synchronous signal
generating circuit 25 and converting an analogue signal to a
digital signal. Following this A/D converting circuit 22, the above
mentioned .[.contact circuit.]. .Iadd.control part .Iaddend.10 is
provided with a frame memory 23a storing the video signal of the
observed part obtained by radiating the illuminating light having
passed through the red (R) wavelength transmitting filter 17a, a
frame memory 23b storing the video signal of the same obtained by
the illuminating light having passed through the green (G)
wavelength range transmitting filter 17b, a frame memory 23c
storing the video signal obtained by the illuminating light having
passed through the blue (B.) wavelength range transmitting filter
17c, a frame memory 23d storing the video signal obtained by the
illuminating light having passed through the infrared (IR)
wavelength range transmitting filter 17dand a frame memory 23e
storing the video signal obtained by the illuminating light having
passed through the ultraviolet (UV) wavelength range transmitting
filter 17e.
The above mentioned frame memories 23a, 23b, 23c, 23d and 23e are
connected to a subtracting circuit 24 which is controlled by a
changing circuit 26 designating any plurality of video signals of
these frame memories 23a, 23b, 23c, 23d and 23e and controlled by
the synchronous signal generating circuit 25 and detects the signal
difference of any plurality of video signals.
Further, the video signal processed by the above mentioned
subtracting circuit 24 is converted from the digital signal to an
analogue signal by a D/A converting circuit 27 and is output in the
television monitor 8.
Now, the synchronous signal generating circuit 25 generates a
reference signal synchronizing the timing of respective active
circuits and controls the entire endoscope apparatus 1.
The operation of the thus formed first embodiment shall be
explained in the following.
The illuminating light emitted from the lamp 11 lighted with an
electric power fed from the lamp power source circuit 12 will enter
the rotary filter 16 along the optical axis 15. This rotary filter
16 will be rotated by the motor 14 rotated and controlled by the
motor driving circuit 13 into which the reference signal output
from the synchronous signal generating circuit 25 is input and the
wavelength range transmitting filters 17a, 17b, 17c, 17d and 17e
provided in the peripheral direction of the above mentioned rotary
filter 16 will be interposed in the optical axis 15 in turn.
Depending on the respective transmitting filters 17a, 17b, 17c, 17d
and 17e, the illuminating light will be separated into the
respective wavelength ranges of red (R), green (G), blud (B),
infrared (IR) and ultraviolet (UV) as shown in FIG. 3. At this
time, the illuminating light will be separated in time series into
the respective wavelength ranges in response to the rotating speed
of the rotary filter 16 and will enter the light guide 4 on the
entrance end surface. The illuminating light entering as separated
in time series into the respective wavelength ranges will be led by
the light guide 4 and will be emitted from the exit end surface of
this light guide 4 to illuminate a part to be observed such as the
body cavity interior of a living body (not illustrated).
At this time, the respective illuminating light separated into the
respective wavelength ranges, that is, of red (R), green (G), blue
(B), infrared (IR) and ultraviolet (UV) will be different when
reflected from the surface layer part of the observed part and
particularly, the longer the wavelength, the deeper the
illuminating light penetrates into the observed part. (This degree
shall be called a penetrating degree hereinafter.)
Therefore, when the illuminating light separated in time series
into the respective wavelength ranges, that is, of red (R), green
(G), blue (B), infrared (IR) and ultraviolet (UV) are radiated to
the observed part, observed image light corresponding to the
respective penetrating degree will be obtained.
The observed image light corresponding in time series to the
respective penetrating degrees will be made to form images in turn
on the solid state imaging device 6 by the observing optical system
5. This solid state imaging device 6 will be driven and controlled
by the CCD driving circuit 18 controlled by the reference signal of
the synchronous signal generating circuit 25, will
photoelectrically convert in turn the observed image light
corresponding to the respective penetrating degrees and will output
electric signals having picture image information corresponding to
the respective penetrating degrees.
The above described electric signals will be amplified by the
pre-amplifying circuit 19.
The electric signals corresponding to the respective penetrating
degrees through this pre-amplifying circuit 19 will have the
exposures sensed by the level sensing circuit 20 and the electric
power fed by the above mentioned lamp power source circuit 12 will
be adjusted to adjust the exposure.
Then, the electric signals including the picture image information
corresponding to the penetrating degrees by the illuminating light
of the red (R), green (G), blue (B), infrared (IR) and ultraviolet
(UV) wavelength ranges will be processed to be video signals by
correcting .gamma., tone and respective wavelength range gains in
the video signal processing circuit 21 controlled by the reference
signal of the synchronous signal generating circuit 25, will be
further converted to digital signals by the A/D converting circuit
22 controlled by the synchronous signal generating circuit 25 and
will be output in turn to the frame memories 23a, 23b, 23c, 23d and
23e. That is to say, the digital signal including the picture image
information corresponding to the penetrating degree by the
illuminating light of the red (R) wavelength range will be stored
in the frame memory 23a. In the same manner, the digital signal
including the picture image information of green (G) will be stored
in the frame memory 23b, the digital signal including the picture
image information of blue (B) will be stored in the frame memory
23c, the digital signal including the picture image information of
infrared (IR) will be stored in the frame memory 23d and the
digital signal including the picture image information of
ultraviolet (UV) will be stored in the frame memory 23e in
turn.
Now, the tone of the observed part on the inside wall of an organ
or the like within the living body or, for example, the tone of the
stomach mucous membrane or the like as an observed part greatly
depends on the hemoglobin existing in the blood. As shown in FIG.
4, the illuminating light absorbing characteristics in the
respective wavelengths of this hemoglobin are greatly different
depending on the wavelength ranges. In FIG. 4, the wavelength
ranges from the ultraviolet (UV) to blue (B), when made
illuminating light, will be large in the amount of the illuminating
light absorbed by hemoglobin, that is, in the amount of attenuation
of the illuminating light and therefore only the information of the
surface state of the mucous membrane will be obtained. The
wavelength ranges from red (R) to infrared (IR) are so small in the
amount of attenuation of the illuminating light in hemoglobin that
not only information about the mucous membrane surface but also
information about the penetrating range of the disease or the
running state of the vein image below the mucous membrane will be
obtained.
Therefore, when the digital signals including the picture image
information corresponding to the penetrating degrees by the
illuminating light of the respective wavelength ranges are stored
in turn in the frame memories 23a, 23b, 23c, 23d and 23e, the
signal difference between the frame memories 23c and 23e storing
the picture image signals of the wavelength ranges from ultraviolet
(UV) to blue (B) including the information about the mucous
membrane surface and the frame memories 23a and 23d storing the
picture image signals of the wavelength ranges from red (R) to
infrared (IR) including the information about the mucous membrane
surface and the information below the mucous membrane will be
detected, that is, subtracted by the subtracting circuit 24 by
setting the changing circuit 26 controlled by the reference signal
of the synchronous signal generating circuit 25.
In this subtracting circuit 24, the picture image signals including
the information of the mucous membrane surface, that is, the
picture image signals stored in the frame memories 23c and 23e are
subtracted from the picture image signals including the information
of the mucous membrane surface and below the mucous membrane,
.[.that it,.]. .Iadd.that is .Iaddend.the picture image signals
stored in the frame memories 23a and 23d.
Therefore, a digital signal having the picture image information of
the penetrating range of the disease or the running state of the
vein image below the mucous membrane will be obtained, will be
converted to an analogue signal by the D/A converter 27 and will be
output as a video image to the television monitor 8.
Here, if the information of the video signals of the respective
wavelength ranges of red (R), green (G), blue (B), infrared (IR)
and ultraviolet (UV) are stored respectively in the frame memories
23a, 23b, 23c, 23d and 23e, by setting the above mentioned changing
circuit 26, picture image information in any plurality of
wavelength ranges will be able to be subtracted.
Thus, according to this embodiment, by the difference between the
penetrating degrees of the illuminating light in the respective
wavelength ranges, for example, the penetrating range of the
disease and the running state of the vein image below the mucous
membrane of the inside wall of an organ or the like of the living
body will not be influenced by the reflection of the illuminating
light on the mucous membrane surface and the part to be observed
can be observed at a high resolution.
By taking out the illuminating light of the wavelength range of
ultraviolet (UV) by subtraction, a picture image, from which the
minute information of the surface in the observed part is obtained,
can be obtained.
Also, the picture images in the wavelength ranges of infrared (R)
and ultraviolet (UV) can be displayed not only in monochrome but
also in quasi colors.
FIGS. 5 to 7 show the second embodiment of the present
invention.
The same as in the first embodiment, this embodiment is applied to
an electronic endoscope imaging apparatus in which a frame
sequential system is adopted.
Therefore, the formation which is different from the first
embodiment of the endoscope imaging apparatus 30 shall be
described.
A light source part 31 provided within the endoscope imaging
apparatus 30 is provided with a lamp 11 emitting illuminating light
in the ultraviolet range, visible light range and infrared range
and a lamp power source circuit 12 feeding an electric power to
this lamp 11 and having the exposure adjusted by a level sensing
circuit 20.
The above mentioned light source part 31 has a motor driving
circuit 13 controlled by a synchronous signal generating circuit
25, a motor 14 connected to this motor driving circuit 13, a rotary
filter 32 provided on the rotary shaft of this motor 14 and
interposed in the optical axis 15 connecting the lamp 11 with a
light guide 4 on the entrance end surface, a filter removably
interposing means 34 controlled by the synchronous signal
generating circuit 25 and set by a changing circuit 33 and an
infrared cutting filter 35 removable interposed in the optical axis
15 by this filter removably interposing means 34 and cutting the
illuminating light in the infrared wavelength range.
As shown in FIG. 6, in the above mentioned rotary filter 32, a
wavelength range transmitting filter 36a having a transmitting
characteristic in the wavelength range of green (G), a wavelength
range transmitting filter 36b having a transmitting characteristic
in the wavelength range of blue (B) and a wavelength ranges
transmitting filter .[.36.]. .Iadd.36c .Iaddend.having a
transmitting characteristic in the wavelength ranges of red and
infrared (R+IR) are arranged in the peripheral direction.
A controlling part 37 processing video signal and sensing a signal
difference or the like is provided with a frame memory 38a storing
the video signal of the observed part obtained by radiating the
illuminating light having passed through the green (G) wavelength
range transmitting filter 36a in the above mention rotary filter
32, a frame memory 38b storing the video signal obtained by the
illuminating light having passed through the blue (B) wavelength
range transmitting filter 36b in the same manner and a frame memory
38c storing the video signal obtained by the illuminating light
having passed through the red and infrared (R+IR) wave length range
transmitting filter 36c.
The other formations in the second embodiment are the same as in
the first embodiment.
The operation of the thus formed second embodiment shall be
explained in the following.
First of all, when the filter removably interposing means 34 is
operated by the changing circuit 33, the infrared cutting filter 35
will be removed from the optical axis 15 shall be explained.
The illuminating light emitted from the lamp 11 will enter the
rotary filter 32 along the optical axis 15. This rotary filter 32
will be rotated and driven by the motor 14 and the wavelength range
transmitting filters 36a, 36b and 36c provided in the peripheral
direction of the rotary filter 32 will be interposed in the optical
axis 15 in turn. By the respective transmitting characteristics of
these wavelength range transmitting filters 36a, 36b and 36c, the
above mentioned illuminating light will be separated into
illuminating light respectively of green (G), blue(B) and red and
infrared (R+IR). At this time, the illuminating light will be
separated into the respective wavelength ranges in time series in
response to the rotating speed of the rotary filter 32, will enter
the light guide 4 on the entrance end surface, will be led by the
light guide 4, will be emitted from the light guide on the exit end
surface and will illuminate such observed part as the body cavity
interior of a living body.
At this time, the penetrating degrees into the mucous membrane
surface layer in the observed part will be different in response to
the respective illuminating light of the respective wavelength
ranges, that is, of green (G), blue (B) and red and infrared
(R+IR). That is to say, the illuminating light of the long infrared
(IR) wavelength range will be larger in the penetrating degree than
the illuminating light of the blue (B) wavelength range.
Therefore, observed image light different in the penetrating degree
in response to green (G), blue (B) and red and infrared (R+IR) will
be obtained in time series.
The observed image light will be made to form images on the solid
state imaging device 6 by the observing optical system 5 and will
be output as electric signals having picture image information of
the observed image light in response to the respective penetrating
degrees by this solid state imaging device.
The above mentioned respective electric signals will be amplified
by the pre-amplifying circuit 19, will be processed to be video
signals by having the .gamma., tone and respective wavelength range
gains corrected by the video signal processing circuit 21 through
the level sensing circuit 20 adjusting the exposure by transmitting
the signals to the lamp power source circuit 12 and will be further
converted to digital signals by the A/D converting circuit 22.
The digital signal including the picture image information
corresponding to the penetrating degree by the illuminating light
of the green (G) wavelength range will be stored in the frame
memory 38a, in the same manner, the digital signal including the
picture image information of green (G) will be stored in the memory
38b and the digital signal including the picture image information
of red and infrared (R+IR) will be stored in the frame memory 38c
in turn.
Now, as in the first embodiment, the tone of an observed part as,
for example, the stomach mucous membrane, depends mostly on the
hemoglobin in the blood which has different absorbing
characteristics of the illuminating light in respective wavelengths
as are shown in FIG. 4.
Therefore, when the digital signals, including the picture image
information corresponding to the penetrating degrees by the
illuminating light of the respective wavelength ranges, are stored
in turn in the frame memories 38a, 38b and 38c, the subtraction of
the frame memory 38b storing the picture image signal of the blue
(B) wavelength range including mostly the information about the
mucous membrane surface and the frame memory 38c storing the
picture image signals of the red and infrared (R+IR) wavelength
ranges including the information about the mucous membrane surface
and below the mucous membrane will be made by the subtracting
circuit 24 by setting the changing circuit 33 controlled by the
reference signal of the synchronous signal generating circuit
.[.25".]. .Iadd.25.Iaddend..
Thus, the digital signal having the picture image information of
the information below the mucous membrane, that is, of the
penetrating range of the disease or the running state of the vein
image is obtained.
Further, the above mentioned digital signals are converted to
analogue signals by the D/A converter 27 and are output as video
images to the television monitor 8.
When the filter removably interposing means 34 is operated by the
changing circuit 33 and the infrared cutting filter 35 is
interposed in the optical axis 15 shall be explained.
The illuminating light emitted from the lamp 11 will be separated
into illuminating light of respective green (G), blue (B) and red
and infrared (R+IR) wavelength ranges by the respective
characteristics of the wavelength range transmitting filters 36a,
36b and 36c provided in the rotary filter 32.
Further, by the infrared cutting filter 35 interposed in the
optical axis 15 forward of the above mentioned rotary filter 32,
the illuminating light separated into the above mentioned
respective wavelength ranges will become illuminating light of the
green (G), blue (B) and red (R) wavelength ranges.
The observed image light obtained by radiating the illuminating
light to the observed part will become respective green (G), blue
(B) and red (R) wavelength ranges.
Therefore, in this embodiment when the filter .[.36.]. .Iadd.35
.Iaddend.is interposed, in addition to the operation and effect in
the first embodiment, as the number of the wavelength range
transmitting filters 36a, 36b and 36c is smaller than of the
wavelength range transmitting filters 17a, 17b, 17c, 17d and 17e in
the first embodiment, the relative aperture rate of the
transmitting filters 36a, 36b and 36c will be high. Therefore, the
observed part can be illuminated at a high illuminating degree and
information about the deeper part of the mucous membrane layer can
be obtained when the filter is interposed.
FIGS. 8 to 10 shows the third embodiment of the present
invention.
This embodiment is applied to an electronic endoscope imaging
apparatus in which a simultaneous system is adopted in the present
invention.
In FIG. 8, an electronic endoscope imaging apparatus 40 is provided
with a light source part .[.41.]. and a control part .[.42.]..
The light source part .[.41.]. is formed of a lamp 11 emitting
illuminating light having wavelengths in the ultraviolet light
range to the visible light range and further to the infrared light
range, a lamp power source circuit 12 feeding an electric power to
this lamp, a tone correcting filter 43 cutting the ultraviolet (UV)
wavelength range and infrared (IR) wavelength range of the
illuminating light emitted from the lamp 11 and a filter removably
interposing means 34 removably interposing the above mentioned tone
correcting filter 43 in the optical axis connecting the above
mentioned lamp 11 with the light guide 4.
An observing optical system 5 and a solid state imaging device
photoelectrically converting an observed image light are arranged
on the tip side of an insertable part 3 of an endoscope 2. A color
separating filter 44 separating the observed image light is secured
on the front surface of the photoelectrically converting zone of
this solid state imaging device and is provided mosaic-like with
filters transmitting the respective color light of cyanine (Cy),
green (G) and yellow (Ye).
Further, the above mentioned endoscope imaging apparatus 40 is
formed of a CCD driving circuit 18 driving the above mentioned
solid state imaging device 6, a pre-amplifying circuit 19
amplifying the electric signal including the picture image
information output from the above mentioned solid state imaging
device 6, a synchronous signal generating circuit 25 generating a
reference signal of the entire endoscope imaging apparatus 40 and a
control part .[.42.]. processing and subtracting video signals.
The above mentioned control part .[.42.]. is provided with an LPF
45 connected to the pre-amplifying circuit 19 and separating a
luminance signal from the electric signal including the picture
image information output from this preamplifying circuit 19. This
LPF 45 is connected to a .gamma. correcting circuit 46 correcting
.gamma..
Also, the above mentioned pre-amplifying circuit 19 is connected to
a BPF 47 separating the frequency of the color signal component.
This BPF 47 is connected to a color separating circuit 50 formed of
a 1H delay line 48, adding circuit 49a and subtracting circuit
.[.496.]. .Iadd.49b.Iaddend.. The adding circuit 49a forming this
color separating circuit 50 is to add a 1H delay signal and an
output signal of the BPF 47 and separate a blue signal. The
subtracting circuit 49b is to subtract the 1H delay signal and the
output signal of the BPF 47 and separate a red signal. The
separated red and blue signals will be output respectively to a
.gamma. correcting circuit 51 correcting the color .gamma. of the
red (R) component and correcting circuit 52 correcting the color
.gamma. of the blue (B) component. The .gamma. correcting circuit
51 is connected to a demodulating circuit 53 demodulating the red
(R) component. The .gamma. correcting circuit 52 is connected to a
demodulating circuit 54 demodulating the blue (B) component.
Further, the above mentioned pre-amplifying circuit 19 is connected
to an LPF 55 separating the green (G) component in the video
signal. The output of this LPF 55 will be input into a .gamma.
correcting circuit 56 correcting .gamma. of green (G).
The output signals of the above mentioned demodulating circuits 53
and 54 and .gamma. correcting circuit 56 color-separated into the
wavelength ranges of red (R), green (G) and blue (B) will be input
into a subtracting circuit 24 subtracting the respective output
signals. The color-separated output signals will be input into a
color encoder circuit 57 and will be converted to color difference
signals.
The video signal from the above mentioned subtracting circuit 24
and the color video signal in the general visible light range from
the above mentioned color encoder circuit 57 will be input into a
changing circuit 58, either of these signals will be selected and
the selected video signal will be output to a television monitor
8.
The output signal of the .gamma. correcting circuit 46 will be
input into a level sensing circuit .[.41.]. .Iadd.20
.Iaddend.adjusting the exposure of the lamp 11.
The operation of the thus formed third embodiment shall be
explained in the following.
The illuminating light emitted from the lamp 11 enters a light
guide 4 on the end surface along an optical axis 15, is led through
this light guide and is emitted from the exit end surface to
illuminate a part to be observed (not illustrated). The observed
image light from the observed part will be made to form an image on
the color separating filter 44 by the observing optical system 5,
will be separated into the colors of cyanine (Cy), green (G) and
yellow (Ye), will be photoelectrically converted by the solid state
imaging device 6, will be read out as electric signals including
the picture image information by cyanine (Cy), green (G) and yellow
(Ye) by the CCD driving circuit 18 synchronized with the reference
signal of the synchronous signal generating circuit 25 and will be
amplified by the pre-amplifying circuit 19.
In order to separate the luminance components and color components
of the electric signals including the amplified picture image
information, the electric signals in the frequency bands including
the picture image information of the component in the red (R)
wavelength range and the component in the blue (B) wavelength range
are taken out by the BPF 47. The component in the red (R)
wavelength range and the component in the blue (B) wavelength range
are separated by the color separating circuit 50 and are .gamma.
corrected respectively by the .gamma. correcting circuits 51 and
52, are demodulated respectively by the demodulating circuits 53
and 54 and are then input into the color encoder circuit 57.
On the other hand, the component in the green (G) wavelength range
can be separated by taking out the output of the pre-amplifying
circuit 19 by the LPF 55 and correcting .gamma. by the .gamma.
correcting circuit 56.
Here, the same as is shown in the first and second embodiments, of
the respective electric signals including the picture image
information of the red (R), green (G) and blue (B) wavelength
ranges different in the penetrating degrees in the mucous membrane
surface layer of a living body, the red (R) component high in the
penetrating degree and including the picture image information of
the mucous membrane surface and below the mucous membrane and the
blue (B) component low in the penetrating degree and including
mostly the picture image information of the mucous membrane are
subtracted to obtain a video signal sensing the picture image
information below the mucous membrane.
The changing circuit 58 generates an NTSC signal by the color
difference signal output from the color encoder circuit 57 and the
luminance signal output from the .gamma. correcting circuit 46 and
changes it for the video signal, output from the subtracting
circuit 24, to combine the subtraction optimum to the observed part
and to compare it with an ordinary color picture image.
At this time, when obtaining the ordinary color picture image, in
order to arrange the tone, a tone correcting filter 43 cutting the
illuminating light in the infrared wavelength range and ultraviolet
wavelength range is interposed in the optical axis 15 by a filter
removably interposing means 34.
Now, FIG. 10 shows spectral output characteristics in the solid
state imaging device 6 of cyanine (Cy), green (G) and yellow (Ye)
using an array of color filters 44.
Thus, according to this embodiment, by using the simultaneous
system, the same as in the first embodiment, by the difference in
the penetrating degrees by the respective wavelength ranges in the
observe part of the living body, not only the picture image
information of the mucous membrane surface but also the penetrating
range of the disease and the vein image below the mucous membrane
can be observed at a high resolution without being influenced by
the reflection on the mucous membrane surface.
The optical filters arranged in the rotary filter 16 and having
transmitting characteristics in the specific wavelength ranges may
be of a supplementary color system.
The subtraction may be made by an analogue signal instead of the
digital signal.
With regard to the observed part in which the penetrating degrees
of the illuminating light in the respective wavelength ranges will
be influenced by colors other than hemoglobin, the wavelength
ranges longer and shorter than the wavelength of 600 nm. as a
boundary are not limited to be substracted but any combination may
be used.
Further, in the respective embodiment, by changing the subtraction
combination from a large penetrating degree wavelength range to a
small penetrating degree wavelength range, the picture image
information corresponding to the respective penetrating degrees can
be obtained. For example, the penetrating range variations of the
disease in the respective depths can be observed.
FIG. 11 shows the fourth embodiment of the present invention.
In this embodiment, as a means of sensing the signal difference
between picture image signals, a television circuit is provided
instead of the subtracting circuit but the other formations are the
same as in the first embodiment.
Frame memories 23a, 23b, 23c, 23d and 23e provided within the
control part 10 are connected to a dividing circuit 60 which is
controlled by a changing circuit 26 designating any video signals
from among a plurality of video signals stored in the frame
memories 23a, 23b, 23c, 23d and 23e. The video signals designated
in this dividing circuit 60 will be divided.
The result of the operation in the above mentioned dividing circuit
60 will be analogized by the D/A converting circuit 27 and will be
output on the television monitor 8.
The endoscope imaging apparatus in the present invention is not
limited to the electronic endoscope but can be used also on an
externally fitted camera to be used on a fiber scope and a TV
camera for observing a living body.
As explained above, according to the present invention, by sensing
a signal difference between at least two kinds of picture image
signals obtained by using illuminating light by wavelengths
different in the penetrating degrees, the reduction of the
resolution by the reflected light on the mucous membrane surface,
which has been the greatest problem, when observing, for example,
the part below the mucous membrane within a living body cavity or
the like can be prevented. Therefore, there is an effect that the
vein running state and disease penetrating range below the mucous
membrane in the observed part can be observed at a high
resolution.
* * * * *