JP2002095635A - Endoscope system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain tissue data at a desired depth near a tissue surface of the body. SOLUTION: A light source device 4 is structured by comprising a xenon lamp 11, a heat ray cut filter 12 which shuts off a heat ray in a white light, an aperture device 13 which controls amount of white light passed through the heat ray cut filter 11, a rotational filter 14 which makes surface sequential light from illumination light that is composed of a first filter group arranged in outside diametrical sections and for the purpose of outputting the surface sequential light of an overlapped spectral property suitable for color recreation, and a second filter group arranged in inside diametrical sections and for the purpose of outputting narrow band surface sequential light of a discrete spectral property capable of extracting tissue data of a desired depth layer, a condenser lens 16 which focuses surface sequential light passed through the rotational filter 14 on incidence faces of light guides 15 disposed in an electron endoscope 3, and a control circuit 17 which controls rotation of the rotational filter 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an endoscope apparatus for capturing an image of a living tissue and processing the signal.

[0002]

2. Description of the Related Art Conventionally, an endoscope apparatus which irradiates illumination light to obtain an endoscopic image in a body cavity has been widely used. In this type of endoscope device, an electronic endoscope having imaging means for guiding illumination light from a light source device into a body cavity by using a light guide or the like and capturing an image of a subject by return light is used, and a video processor is used. An endoscope image is displayed on an observation monitor by performing signal processing on an image pickup signal from the image pickup means, and an observation site such as an affected part is observed.

When ordinary living tissue observation is performed with an endoscope device, a light source device emits white light in the visible light region,
For example, the subject is irradiated with plane-sequential light through a rotation filter such as RGB, and the return light due to the plane-sequential light is synchronized with a video processor to perform image processing, thereby obtaining a color image, A color chip is arranged on the front surface of the imaging surface, and return light by white light is RGB by the color chip.
Then, a color image is obtained by taking an image by separating the image and processing the image with a video processor.

[0004] On the other hand, in living tissue, light absorption and scattering characteristics differ depending on the wavelength of the irradiated light.
For example, various infrared endoscope apparatuses have been proposed that can irradiate a living tissue with infrared light as illumination light and observe a tissue deep in the living tissue.

[0005]

However, in diagnosing a living tissue, deep tissue information near the tissue surface is also an important observation object. However, in the infrared endoscope apparatus described above, a deep portion of the tissue is deeper than the tissue surface. Only organization information can be obtained.

Also, white light is converted into RGB light by a rotation filter.
When a living tissue is irradiated as plane-sequential light, the wavelength range is different. Therefore, the imaging signal by the light of each color has different deep tissue information near the tissue surface of the living tissue. In order to make the endoscope image by the light into a more natural color image in order, the white light is separated into RGB light in which each wavelength region overlaps.

In other words, in the overlapped RGB light, a wide depth of tissue information is captured in an image signal of light in each wavelength range, so that desired deep tissue information near the tissue surface of a living tissue can be visually recognized. Is difficult.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide an endoscope apparatus and a light source apparatus which can obtain desired deep tissue information near a tissue surface of a living tissue. I have.

[0009]

An endoscope apparatus according to the present invention comprises:
Illumination light supply means for supplying illumination light including a visible light region,
An endoscope having an imaging unit that irradiates the object with the illumination light and images the object with return light; and an endoscope device including a signal processing unit that performs signal processing on an imaging signal from the imaging unit. A band limiting unit that limits at least one of a plurality of wavelength ranges of the illumination light and forms a band image of a discrete spectral distribution of the subject on the imaging unit from the illumination light supply unit to the imaging unit; It is configured to be provided on the optical path leading to.

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 to 33 relate to a first embodiment of the present invention. FIG. 1 is a configuration diagram showing a configuration of an endoscope apparatus.
2 is a configuration diagram showing the configuration of the rotary filter of FIG. 1, FIG. 3 is a diagram showing spectral characteristics of a first filter set of the rotary filter of FIG. 2, and FIG. 4 is a second filter set of the rotary filter of FIG. FIG. 5 is a diagram showing a layered structure of a living tissue observed by the endoscope apparatus of FIG. 1, and FIG. 6 is a diagram showing a layered direction of living tissue of illumination light from the endoscope apparatus of FIG. FIG. 7 is a view showing each band image by plane-sequential light transmitted through the first set of filters in FIG. 3, and FIG. 8 is a plane sequential transmitted through the second set of filters in FIG. FIG. 9 is a diagram showing each band image by light, FIG. 9 is a diagram for explaining dimming control by the dimming circuit in FIG. 1, and FIG. 10 is a spectral characteristic of a first modification of the second filter set of the rotary filter in FIG. FIG. 11 is a diagram showing spectral characteristics of a second modification of the second filter set of the rotary filter of FIG. 2; 2 is a diagram showing the spectral characteristics of a third modification of the second filter set of the rotary filter of FIG. 2, and FIG. 13 is a diagram illustrating the operation of the third modification of the second filter set of the rotary filter of FIG. FIG. 14 is a diagram showing a first example of the spectral distribution of the xenon lamp of FIG. 1, and FIG. 15 is a fourth modification of the second filter set of the rotating filter in the case of the spectral distribution of the xenon lamp of FIG. FIG. 16 is a diagram showing spectral characteristics of an example, and FIG.
FIG. 17 is a diagram showing spectral characteristics of living tissue illumination light according to a fourth modification of the second filter set of FIG. 4, FIG. 17 is a diagram showing a second example of the spectral distribution of the xenon lamp of FIG. 1, and FIG. CC
FIG. 19 is a diagram showing an example of the spectral sensitivity characteristic of D. FIG. 19 is the fifth example of the second filter set of the rotary filter when the spectral distribution of the xenon lamp is the second example and the spectral sensitivity characteristic of the CCD is FIG.
The figure showing the spectral characteristics of the neutral density filter deposited in the modified example of
FIG. 20 is a diagram showing the spectral characteristics of a fifth modification of the second filter set in which the neutral density filter of FIG. 19 is deposited, and FIG.
FIG. 22 is a configuration diagram showing a configuration of a first modification of the light source device of FIG.
FIG. 2 is a configuration diagram showing the configuration of the dimming rotation filter of FIG.
3 is a configuration diagram showing a configuration of a second modification of the light source device in FIG. 1, FIG. 24 is a diagram showing the dimming characteristics of a first dimming filter constituting the dimming filter in FIG. 23, and FIG. 23 is a diagram showing the dimming characteristics of the second dimming filter constituting the dimming filter of FIG. 23, FIG. 26 is a diagram showing the dimming characteristics of the dimming filter of FIG. 23, and FIG. 27 is the second diagram of the rotating filter of FIG. FIG. 28 is a diagram showing an example showing detailed spectral characteristics of the filter set of FIG. 28, FIG. 28 is a diagram showing spectral characteristics of a sixth modification of the second filter set of the rotary filter of FIG. 2, and FIG. 29 is a video processor of FIG. FIG. 30 is a first diagram illustrating the operation of the video processor of FIG. 29, FIG. 31 is a second diagram illustrating the operation of the video processor of FIG. 29, and FIG. FIG. 33 is a view showing a seventh modification of the second filter set of the rotary filter of FIG. 2; It is a diagram illustrating a second spectral characteristic of the second filter set of the seventh modified example.

As shown in FIG. 1, an endoscope apparatus 1 according to the present embodiment includes an electronic endoscope 3 having a CCD 2 as an image pickup means for inserting into a body cavity and imaging tissue in the body cavity, and an electronic endoscope. A light source device 4 for supplying illumination light to the light source 3 and a C of the electronic endoscope 3
A video processor 7 processes an image signal from the CD 2 to display an endoscope image on the observation monitor 5 or encodes the endoscope image and outputs it to the image filing device 6 as a compressed image.

The light source device 4 includes a xenon lamp 11 that emits illumination light, a heat ray cut filter 12 that cuts off heat rays of white light, an aperture device 13 that controls the amount of white light passing through the heat ray cut filter 12, A rotating filter 14 for converting illumination light into a surface-sequential light, a condenser lens 16 for condensing surface-sequential light via the rotating filter 14 on an incident surface of a light guide 15 disposed in the electronic endoscope 3, Rotary filter 1
4 and a control circuit 17 for controlling the rotation.

As shown in FIG. 2, the rotary filter 14
It has a disk-like structure and has a double structure with the center as a rotation axis. The outer diameter portion is for outputting plane-sequential light having overlapping spectral characteristics suitable for color reproduction as shown in FIG. R1 filters 14r1, which constitute the first filter set,
A G1 filter 14g1 and a B1 filter 14b1 are arranged,
In the inner diameter portion, R2 filters 14r2 and R2 constituting a second filter set for outputting narrow band plane-sequential light having discrete spectral characteristics from which desired deep tissue information can be extracted as shown in FIG. A G2 filter 14g2 and a B2 filter 14b2 are arranged. Then, as shown in FIG. 1, the rotary filter 14 is controlled by the control
8 is rotated and moved in the radial direction (movement perpendicular to the optical path of the rotary filter 14, and the first filter set or the second filter set of the rotary filter 14 is selectively placed on the optical path). The movement is performed by the mode switching motor 19 according to a control signal from a mode switching circuit 42 in the video processor 7 described later.

The xenon lamp 11, the aperture device 1
3. Rotary filter motor 18 and mode switching motor 19
Is supplied with power from the power supply unit 10.

Returning to FIG. 1, the video processor 7
A CCD drive circuit 20 for driving D2, and an objective optical system 21
, An amplifier 22 that amplifies an image signal obtained by imaging the tissue in the body cavity by the CCD 2 via the CCD 2, a process circuit 23 that performs correlated double sampling, noise removal, and the like on the image signal that has passed through the amplifier 22, and a process circuit 23. A / D converter 2 for converting an imaging signal into digital signal image data
4, a white balance circuit 25 for performing white balance processing on image data from the A / D converter 24, a selector 26 for synchronizing plane-sequential light by the rotary filter 14, and synchronizing memories 27, 28, 29. An image processing circuit 30 that reads out the image data of the field sequential light stored in the synchronization memories 27, 28, and 29 and performs gamma correction processing, contour enhancement processing, color processing, and the like, and outputs image data from the image processing circuit 30. D / A circuits 31 and 3 for converting to analog signals
2, 33, an encoding circuit 34 for encoding the outputs of the D / A circuits 31, 32, 33, and a synchronizing signal synchronized with the rotation of the rotary filter 14 from the control circuit 17 of the light source device 4 and various timings. And a timing generator 35 that outputs a signal to each of the above circuits.

The electronic endoscope 2 is provided with a mode changeover switch 41.
1 is a mode switching circuit 42 in the video processor 7
Is output to The mode switching circuit 42 of the video processor 7 outputs a control signal to the dimming circuit 43, the dimming control parameter switching circuit 44, and the mode switching motor 19 of the light source device 4. The dimming control parameter switching circuit 44 outputs a dimming control parameter corresponding to the first filter set or the second filter set of the rotary filter 14 to the dimming circuit 43. Based on the control signal and the dimming control parameter from the dimming control parameter switching circuit 44, the diaphragm device 13 of the light source device 4 is controlled to perform appropriate brightness control.

Next, the operation of the thus configured endoscope apparatus of the present embodiment will be described.

As shown in FIG. 5, the tissue 51 in the body cavity often has an absorber distribution structure such as a blood vessel different in the depth direction. Many capillaries 52 are mainly distributed near the surface layer of the mucous membrane, and in the middle layer deeper than this layer, a blood vessel 53 thicker than the capillaries is distributed in addition to the capillaries, and a thicker blood vessel 54 is further distributed in the deeper layer. become.

On the other hand, the light reaches the tissue 51 in the body cavity in the depth direction of the light depending on the wavelength of the light. As shown in FIG. ) In the case of light with a short wavelength such as color, light can only reach the surface layer due to absorption and scattering characteristics in living tissue, and is absorbed and scattered within the range of the depth, and exits from the surface. Light is observed. In the case of green (G) light having a wavelength longer than that of blue (B) light, the light reaches deeper than the range where blue (B) light deepens, and is absorbed and scattered in that range and exits from the surface. Light is observed. Furthermore, red (R) light, which has a longer wavelength than green (G) light, reaches a deeper range.

At the time of normal observation, the R1 filter 14 as the first filter set of the rotary filter 14 is provided on the optical path of the illumination light.
The mode switching circuit in the video processor 7 controls the mode switching motor 19 according to the control signal so as to be located at r1, the G1 filter 14g1, and the B1 filter 14b1.

R 1 at the time of normal observation of the tissue 51 in the body cavity
Filter 14r1, G1 filter 14g1, B1 filter 1
4b, as shown in FIG. 3, since the respective wavelength ranges overlap each other, the imaging signal captured by the CCD 4 using the B1 filter 14b1 contains a large amount of tissue information in a shallow layer as shown in FIG. A band image having tissue information including shallow and middle layers is captured, and the C1 image is obtained by the G1 filter 14g1.
As shown in FIG. 7B, a band image having shallow-layer and middle-layer tissue information containing a large amount of tissue information in the middle layer is captured as an image signal captured by the CD4.
FIG. 7 shows an image pickup signal picked up by the CCD 4 by r1.
A band image having middle and deep tissue information including a large amount of tissue information at the deep layer as shown in FIG.

Then, by synchronizing the RGB image signals with the video processor 7 and performing signal processing, it is possible to obtain an endoscope image having a desired or natural color reproduction as the endoscope image.

On the other hand, when the mode changeover switch 41 of the electronic endoscope 3 is pressed, the signal is inputted to the mode changeover circuit 42 of the video processor 7. Mode switching circuit 42
Outputs a control signal to the mode switching motor 19 of the light source device 4 to move the first filter set of the rotary filter 14 that was on the optical path during normal observation and dispose the second filter set on the optical path. The rotary filter 14 is driven with respect to the optical path as described above.

The R2 filter 14r2, the G2 filter 14g2, and the B2 filter 14b2 at the time of narrow-band light observation of the tissue 51 in the body cavity by the second filter set cause the illumination light to have a narrow discrete spectral characteristic as shown in FIG. In order to obtain band-sequential light in a sequential manner, a band image having tissue information in a shallow layer as shown in FIG. A band image having tissue information in the middle layer as shown in FIG. 8 (b) is picked up by an image pickup signal picked up by the CCD 4 by the 14g2, and furthermore, a CC image by the R2 filter 14r2 is picked up.
A band image having tissue information in a deep layer as illustrated in FIG. 8C is captured in the imaging signal captured in D4.

At this time, as is apparent from FIGS. 3 and 4, the amount of light transmitted by the second filter set is smaller than the amount of light transmitted by the first filter set because the band becomes narrower. The control parameter switching circuit 44 outputs a dimming control parameter corresponding to the first filter set or the second filter set of the rotary filter 14 to the dimming circuit 43, so that the dimming circuit 43 controls the diaphragm device 13. Then, as shown in FIG. 9, the aperture device 1 at the time of normal observation according to the set value Lx on a setting panel (not shown) of the video processor 7.
For narrow linear light observation, for example, a linear aperture control line 61 by 3 is used to control the aperture device 13 to control the light amount Mx by an aperture control curve 62 corresponding to the set value Lx.

Specifically, in conjunction with the change from the first filter set to the second filter set, the light amount set value Lx
The aperture level value corresponding to is changed from Mx1 to Mx2 as shown in FIG. 9, and as a result, the aperture is controlled in the opening direction, and the reduction of the illumination light amount due to the narrow band of the filter is compensated. To work.

As a result, image data with sufficient brightness can be obtained even during narrow-band light observation.

As described above, in the present embodiment, during normal observation of the tissue 51 in the body cavity, the mode switch 41 is depressed as necessary, so that the first filter set of the rotary filter 14 is switched to the second filter set. In this narrow-band light observation, the tissue information of each layer of the body cavity tissue 51 is obtained as an imaging signal in a separated state by the second filter set of the rotating filter 14. In addition, since the imaging signal of an appropriate amount of light can be obtained by controlling the diaphragm device 13, the tissue information of each layer of the tissue 51 in the body cavity, which is important for diagnosis, can be separated at the layer level and reliably viewed. Thus, the state of the tissue 51 in the body cavity can be more accurately diagnosed.

The second filter set includes a filter set (R2 filter 14) as shown in FIG.
r2, G2 filter 14g2, B2 filter 14b2). However, the present invention is not limited to this. As a first modified example of the second filter set, for example, a narrow band of discrete spectral characteristics as shown in FIG. It may be a filter set that generates a light in a sequential manner. In the filter set of the first modified example, the G filter and the R filter are the same as the G filter and the R filter of the first filter set, and only the B filter is narrowed. This is particularly suitable when attention is paid to a capillary structure or the like near the surface of the living tissue, and other band images may be the same as conventional images.

The filter characteristics are not limited to the visible light range. As a second modification of the second filter set, the illumination light is converted into a narrow band plane-sequential light having discrete spectral characteristics as shown in FIG. A filter set that generates light may be used. The filter set according to the second modification is configured to set B to a near-ultraviolet region and R to a near-infrared region in order to observe irregularities on the surface of a living body and an absorber near a very deep layer. This is suitable for obtaining image information that cannot be obtained.

Further, as a third modified example of the second filter set, as shown in FIG.
A filter set including two filters 2a and B2b that are close to each other in a short wavelength range may be used. This is suitable for imaging a delicate difference in scattering characteristics rather than absorption characteristics by utilizing the fact that the wavelength band in the vicinity extends only to the vicinity of the very surface layer of a living body. That is, as shown in FIG. 13, when a filter is formed at a position where the scattering characteristic changes greatly so that the absorption characteristics of the living body become substantially equal at the center wavelength of B2a and B2b, the near-surface scattering characteristics can be imaged. It is suitable for. Medically, it is assumed that the present invention is used for discriminating and diagnosing diseases such as early cancer, which have disordered cell arrangement near the mucosal surface layer.

Generally, a xenon lamp or the like is often manufactured so as to block ultraviolet light. FIG. 14 shows an example of the spectral distribution of the illumination light source. For this reason, in the B region of the second filter set, even if the short wavelength side is set as an open characteristic as a transmission region as shown in FIG. 15, the characteristic as shown in FIG. 16 is obtained in combination with the spectral characteristics of the light source. Band illumination light characteristics can be realized. In addition, when manufacturing an optical filter, it is often the case that a multilayer interference film filter is usually deposited, and in the manufacturing method, in order to narrow the band of the spectral transmittance characteristic, a number of layers must be deposited,
Therefore, there is a problem that the cost is increased and the thickness of the filter is increased. However, by making the one side open using the lamp characteristics, the manufacturing cost and the thickness can be reduced.

When the spectral distribution of the light source is as shown in FIG. 17 and the spectral sensitivity characteristic of the CCD is as shown in FIG.
In conjunction with switching to the filter set of, the dimming is set brighter to compensate for the decrease in light amount due to the narrowing of the band. As a result, the B2 band image is appropriate, but the G2 band image and the R2 band image are slightly saturated. It can be considered. Alternatively, the white balance is adjusted by the white balance circuit 25 of FIG. 1, and as a result, the B2 band image having a low brightness level is excessively amplified by the second filter set, the light source device, and the CCD sensitivity characteristic, and the SN is poor. An image will be observed.

Therefore, it is necessary to control not only the band characteristic but also the peak transmittance characteristic in consideration of the spectral distribution of factors that affect the system spectral sensitivity, such as the light source spectral distribution characteristic and the CCD spectral sensitivity characteristic.

Therefore, as shown in FIG. 19, a fifth modification of the second set of filters for obtaining an image of appropriate brightness in consideration of the system spectral sensitivity characteristics other than the filters and the dimming characteristics. A neutral density filter having various neutral density characteristics a and b may be formed by vapor deposition or bonding to the R2 filter 14r2 and the G2 filter 14g2 of the rotary filter 14. As a result, a narrow band filter set having the characteristics shown in FIG. 20 can be obtained. Thus, not only the band characteristics. Its transmittance characteristics can also be set appropriately,
An image with the optimal brightness can be observed in each band.

The method of controlling not only the band characteristic but also the peak transmittance characteristic in consideration of the spectral distribution of factors that affect the system spectral sensitivity such as the light source spectral distribution characteristic and the CCD spectral sensitivity characteristic is reduced as described above. The optical filter is an R2 filter 14r2 of the rotary filter 14, a G2 filter 14g2.
In addition to vapor deposition or bonding, as shown in FIG.
The first modified example of the light source device 4 may be configured by providing a dimming rotation filter 61 on the optical path separately from the rotation filter 14. As shown in FIG. 22, the dimming rotary filter 61 has the same double structure as the rotary filter 14 (see FIG. 2), and the R1 filter 14r of the rotary filter 14
1, each part corresponding to the G1 filter 14g1, the B1 filter 14b1, and the B2 filter 14b2 is a transmission part.
Dimming filters 62, 6 for dimming the respective band lights only at the portions corresponding to the filters 14r2 and the G2 filter 14g2.
It is 3. The dimming rotation filter 61 is driven to rotate by a rotation filter motor 64 based on a control signal of the control circuit 17 similarly to the rotation filter 14, and is controlled by a mode switching motor 65 based on a control signal from the mode switching circuit 42. The radial direction can move perpendicular to the optical path, and the drive timing is synchronized with the rotation filter 14.

The method of controlling not only the band characteristic but also the peak transmittance characteristic in consideration of the spectral distribution of elements that affect the system spectral sensitivity such as the light source spectral distribution characteristic and the CCD spectral sensitivity characteristic is described above. As shown in FIG. 23, instead of the light source device provided with the dimming rotation filter 61, as shown in FIG. 23, the mode of the dimming filter 71 having a desired band transmittance is switched by combining a plurality of filters in the second modified example of the light source device 4. It can be inserted and removed from the optical path by the filter moving motor 72 based on a control signal from the circuit 42,
The driving is performed by removing the rotary filter 14 during the first filter and inserting the rotary filter 14 during the second filter. This neutral density filter 71 is obtained by combining a first neutral density filter having the neutral density characteristics shown in FIG. 24 with a second neutral density filter having the neutral density characteristics shown in FIG.
By providing such a dimming characteristic, not only the band characteristic but also the peak transmittance characteristic can be controlled.

As an example of specific spectral characteristics of the R2 filter 14r2, G2 filter 14g2, and B2 filter 14b2, as shown in FIG.
4r2 has a wavelength band including 600 nm and a half width of 20 to 40.
The G2 filter 14g2 has a band width of 540 nm and a band width of 20 to 40 nm, and the B2 filter 14b2 has a band width of 420 nm and a band width of 20 to 40 nm. Has path characteristics.

When the spectral characteristics are as shown in FIG.
420 in the visible light region where blood absorption is large
By observing with illumination light having a narrow band characteristic including nm,
Capable of reproducing the capillary structure on the mucosal surface with high contrast, and the depth distribution of the absorber in the living mucosa can be reproduced in different colors, and the relative position of the absorber in the depth direction such as a blood vessel image Can be overviewed.

As a modification of the R2 filter 14r2, G2 filter 14g2, and B2 filter 14b2, a G 'filter 14g' having spectral characteristics as shown in FIG.
The G "filter 14g" and the B2 filter 14b2 may be used. In this case, the G 'filter 14g' has a wavelength band of 55.
The G "filter 14g" has a bandpass characteristic of 20 to 40 nm including a wavelength band of 500 nm including a wavelength band of 20 nm to 40 nm, and the B2 filter 14b2 has a bandpass characteristic of a wavelength band of 420 nm including a wavelength band of 500 nm. And has a band pass characteristic of a half value width of 20 to 40 nm.

When the spectral characteristics as shown in FIG. 28 are obtained,
420 in the visible light region where blood absorption is large
By observing with illumination light having a narrow band characteristic including nm,
In addition to being able to reproduce high-contrast capillary structures on the mucosal surface and providing band-pass light near 500 nm as an adjacent wavelength band, image reproduction specialized for the structure of the mucosal surface can be realized.

In conjunction with the change from the first filter set to the second filter set, the aperture level value corresponding to the light amount set value Lx is changed from Mx1 to Mx2 as shown in FIG.
As a result, the aperture is controlled in the opening direction, and the filter operates to compensate for the decrease in illumination light amount due to the narrow band of the filter. May be raised.

However, since the living body to be the subject is not always stationary but involves peristalsis and pulsation, if a freeze operation is performed during image observation, the image moves during exposure to the CCD. The increase in the amount of irradiation due to the extension of the exposure time causes a problem that the image blur increases.

Therefore, as a modified example of the video processor 7, as shown in FIG. 29, pre-freeze memories 200, 201, and 202 for always recording images of several frames.
Is provided at the subsequent stage of the synchronization memories 27, 28, and 29, and a motion detection circuit 210 that compares image data between fields based on an output signal of the synchronization memories 27, 28, and 29 and an input signal of the selector 26 to detect a motion is provided. Provide.

With this configuration, the electronic endoscope 3
When the mode switching instruction switch 41 provided in the controller is pressed, the mode switching circuit 42
And the exposure time is doubled by the control circuit 17 of the light source device 4 as compared with the normal observation (the rotation speed of the second filter set of the rotary filter 14 is half of the rotation speed of the first filter set).
The rotation of the rotary filter 14 is controlled as follows.

When the freeze switch 205 provided on the electronic endoscope 3 is depressed, for example, at the timing shown in FIG. 30 for normal observation and at the timing shown in FIG.
At timing 1, the motion detection circuit 210 compares the image data between the fields to detect a motion,
Update of image data recorded in 00, 201, and 202 is controlled.

More specifically, taking the case of normal observation in FIG. 30 as an example, for example, the image data R0 of one field period stored in the synchronization memory 27 by the motion detection circuit 210
And the one-field period image data G0 input to the selector 26 (first comparison). Further, the one-field period image data G0 stored in the synchronization memory 28 and the one-field period input to the selector 26 are compared. (Second comparison), and when it is determined that there is no motion, the mode switching circuit 42 controls the timing generator 35 to store the memories 200 and 201 in the next field period (* period in the figure). , 202 to the synchronization memories 27, 2
The image data R0, G0, B0 stored in 8, 29 are written.

The motion detection circuit 210 uses the second
As a result of the comparison, it is determined that there is no motion, and the image data B for one field period stored in the synchronization memory 29
0 is compared with the image data R1 for one field period input to the selector 26 (third comparison). If it is determined that there is no motion in the result of the third comparison, the mode switching circuit 42 35 in the next field period (the period in the figure).
1, 202 are updated and the synchronization memories 27, 28, 29
The image data R1, G0, and B0 stored in the memory 200, 2 are not updated in the above-mentioned period when it is determined that there is a motion as a result of the third comparison.
01 and 202 hold data recorded in the * period.

In this way, the memories 200, 201, 2
02 is sequentially updated in the next field. Note that the exposure time is only doubled during narrow band observation.
1, similar updates are made to the memories 200, 201, and 202.

When the freeze switch 205 provided on the electronic endoscope 3 is pressed, the mode switching circuit 42
Controls the timing generator 35, stops reading from the synchronization memories 27, 28 and 29,
The image data read from 0, 201, and 202 is output to the image processing circuit 30.

However, when there is no image data in the memories 200, 201, and 202, or immediately after the mode switching instruction switch 41 is pressed to switch to the second filter set of the rotary filter 14, the motion is detected by the motion detecting circuit 210. Until the detection, the reading from the synchronization memories 27, 28, and 29 is continued even if the freeze switch 205 is pressed.
The reading from 28 and 29 is stopped.

As shown in FIG. 29, the memories 200, 201, 2
02 and the motion detection circuit 210, when the exposure time is extended during narrow-band observation,
An image in which blurring of the image is minimized can be obtained.

In general, a fluorescence image of a living tissue by excitation light does not reflect the fine structure of the mucous membrane surface.
Clarify the presence of lesions that are difficult to detect with visible light. On the other hand, it is known that the fine structure of the mucosal surface such as a capillary blood vessel image is important information for differential diagnosis of a lesion.
Therefore, the diagnostic capability may be improved by combining these two pieces of information and displaying them as an image.

Specifically, instead of the R2 filter 14r2, the G2 filter 14g2, and the B2 filter 14b2, FIG.
As shown in FIG. 2, an F filter 14f for excitation light and G2
The filter 14g2 and the B2 filter 14b2 constitute a second filter set of the rotary filter. Here, the spectral characteristics of the excitation light F filter 14f are as shown in FIG.

When the living tissue is irradiated with the excitation light of a narrow band by the F filter 14f, fluorescence having a wavelength as shown in FIG. 33 is emitted from the living tissue. Therefore, it is possible to switch between the normal observation in which the color reproduction characteristic having the broadband characteristic is emphasized as in the above-described embodiment and the high-performance observation using an image in which the fluorescent light and the narrow-band light are superimposed.

As described above, it is possible to observe a lesion which is difficult to be detected by visible light by fluorescence observation, and to perform detailed observation of the mucous membrane surface with narrow band light, so that diagnostic performance can be improved.

FIGS. 34 to 36 relate to the second embodiment of the present invention. FIG. 34 is a configuration diagram showing the configuration of the endoscope apparatus, FIG. 35 is a configuration diagram showing the configuration of the rotary filter of FIG. FIG. 36 is a diagram showing the spectral characteristics of the color chip of FIG.

Since the second embodiment is almost the same as the first embodiment, only different points will be described, and the same components will be denoted by the same reference numerals and description thereof will be omitted.

As shown in FIG. 34, in the electronic endoscope 3 according to the present embodiment, a color chip 81 is arranged on the front surface of the CCD 2 to constitute a color CCD 2a. Is composed. Color CCD 2a
Is converted into color image data by an A / D converter 24, is color-separated by a color separation circuit 82, is input to a white balance circuit 25, and is
After the image data is stored in the memories 83, 84, and 85 via the interface 6, the image processing circuit 30 performs an interpolation process or the like, and then performs a desired image process.

The rotary filter 86 of the light source device 4 has the structure shown in FIG.
As shown in FIG. 7, the control circuit 1 includes an R2 filter 14r2, a G2 filter 14g2, and a B2 filter 14b2 having spectral characteristics similar to those of the second filter set of the first embodiment.
7, is driven to rotate by the rotary filter motor 18 based on the control signal from the mode changeover switch 42 provided on the electronic endoscope 3, and receives a command signal from the mode switching circuit 42 based on the control signal from the mode switching circuit 42. To be inserted into and removed from the optical path.

In the present embodiment configured as described above,
During normal observation, the rotary filter 86 is removed from the optical path, and white light is applied to the living tissue. Then, the biological tissue image by the white light is captured by the color CCD 2a. At this time, the spectral characteristics of the color chip 81 on the front surface of the CCD 2 are shown in FIG.

On the other hand, at the time of narrow-band light observation, the rotating filter 86 is inserted on the optical path, and the living tissue is irradiated with the field sequential light by the R2 filter 14r2, G2 filter 14g2, and B2 filter 14b2. Then, an image of the living tissue by this plane-sequential light is captured by the color CCD 2a.

Therefore, at the time of narrow-band light observation, the R2 filter 14r2, the G2 filter 14g2, and the B2 filter 14b
Since the living tissue is irradiated with the surface normal light having discrete narrow band spectral characteristics according to 2, the same effects as those of the first embodiment can be obtained in this embodiment.

FIGS. 37 to 46 relate to the third embodiment of the present invention. FIG. 37 is a block diagram showing the configuration of the endoscope apparatus, and FIG. 38 shows the band-pass characteristics of the band limiting filter of FIG. FIGS. 39 and 39 show spectral characteristics of discrete narrow-band plane-sequential light by the band-limiting filter of FIG. 38.
FIG. 41 is a diagram showing band-pass characteristics of a first modification of the band-limiting filter of FIG. 37, FIG. 41 is a diagram showing spectral characteristics of discrete narrow-band plane-sequential light by the band-limiting filter of FIG. 40, and FIG. FIG. 43 is a diagram showing bandpass characteristics of a second modification of the band limiting filter of FIG. 37, FIG. 43 is a diagram showing an example of the spectral characteristics of the xenon lamp of FIG. 37, and FIG. FIG. 45 is a diagram showing bandpass characteristics of a third modification of the band limiting filter of FIG. 37, and FIG.
FIG. 46 is a configuration diagram showing a configuration of a modification of the light source device of FIG.
FIG. 5 is a diagram illustrating a configuration of a neutral density rotating filter of No. 5;

Since the third embodiment is almost the same as the first embodiment, only different points will be described, and the same components will be denoted by the same reference numerals and description thereof will be omitted.

As shown in FIG. 37, the light source device 4 of the present embodiment has an R1 filter 14r1, a G1 filter 14g1,
A rotary filter 91 on which the B1 filter 14b1 is arranged;
A band limiting filter 92 having bandpass characteristics (R2 band, G2 band, B2 band) having a multimodal band as shown in FIG.
1 is rotationally driven by the rotary filter motor 18 based on a control signal from the control circuit 17, and the band limiting filter 92 is a filter moving motor 87 based on a control signal from the mode switching circuit 42 which has received an instruction signal from the mode switching switch 41. To be inserted into and removed from the optical path.

In the present embodiment configured as described above,
By inserting the band limiting filter 92 in the optical path, the plane-sequential light transmitted through the rotation filter 91 becomes discrete narrow-band plane-sequential light as shown in FIG. Since the living tissue is irradiated, the same effects as those of the first embodiment can be obtained in this embodiment.

In the present embodiment, the band limiting filter 92 is configured to have a narrow band characteristic in three bands of RGB as shown in FIG. 38, but is not limited to this.
When it is desired to improve the observability of only the surface structure of the living body, it is not necessary to narrow all the three bands.
Since only the band needs to be narrower, a band-limiting filter having a deformable multi-peak band-pass characteristic may be used as shown in FIG. 40. Such a band-limiting filter may be an RGB rotation filter. By combining this with 91, it is possible to irradiate living tissue with plane-sequential light having narrow band characteristics only in the B band as shown in FIG.

In order to provide only the B band with a narrow band characteristic, the band limiting filter 92 is changed to RGB as shown in FIG.
The band-limiting filter may be such that the light is only B 'light. As a specific example of the narrow-band characteristic of only B', the long band has a band-pass characteristic of 420 nm and a half-value width of 20 to 40 nm. .

When the spectral characteristics as shown in FIG. 42 are obtained,
420 in the visible light region where blood absorption is large
By observing with illumination light having a narrow band characteristic including nm,
Capable of reproducing high-contrast capillary structures on the mucosal surface.

In the case where the cutoff characteristic of the rotary filter 91 on the short wavelength side can be used, such as when the xenon lamp has a characteristic in which the spectral characteristic is attenuated in the short wavelength range as shown in FIG. As shown at 44, a band-limiting filter may be used as shown in “Short wavelength side has open characteristics instead of bandpass characteristics”.

Considering that the energy of the lamp is reduced in the short wavelength region and that the spectral sensitivity characteristic of the CCD is reduced in this region, the color adjustment processing such as white balance results in a B2 band image. Has an excessively increased gain, resulting in a very noisy image.

Therefore, as a modification of the light source device, FIG.
As shown in FIG. 7, a dimming rotation filter 95 is provided on the optical path.
After the white balance is taken into consideration by taking into account the spectral characteristics other than the filters such as the lamp and the CCD, the respective light sources can be configured to have appropriate SN characteristics. Adjust the light intensity.

That is, as shown in FIG. 46, each part of the rotary filter 91 corresponding to the B1 filter 14b1 is a transmission part, and the R1 filter 1
A portion corresponding to the 4r1 and G1 filter 14g1 is configured as a neutral density filter for dimming each band light. The dimming rotation filter 95 is driven to rotate by a rotation filter motor 96 based on a control signal of the control circuit 17 similarly to the rotation filter 91, and the mode switching circuit 42
The radial direction can be moved vertically with respect to the optical path by the mode switching motor 97 based on the control signal from the controller, and the drive timing is synchronized with the rotation filter 91.

FIGS. 47 to 50 relate to the fourth embodiment of the present invention. FIG. 47 is a view showing the structure of an endoscope apparatus. FIG. FIG. 49 is a diagram showing an example of the spectral distribution of light, FIG. 49 is a diagram showing the illumination timing of each band by the power supply unit in FIG. 47, and the light amount control timing at that time, and FIG. FIG. 3 is a diagram illustrating an example of a spectral distribution of light emitted from a light source device.

Since the fourth embodiment is almost the same as the third embodiment, only different points will be described, and the same components will be denoted by the same reference numerals and description thereof will be omitted.

In the light source device of this embodiment, as shown in FIG. 47, the power supply unit 10 can change the driving voltage of the xenon lamp 11 by receiving a control signal from the dimming circuit 43.

Considering the characteristics of the lamp, the spectral distribution of the light emitted from the actual light source device is as shown in FIG. The lamp has reduced energy in the short wavelength range,
Considering that the CD spectral sensitivity characteristic decreases in this region, the B2 band image becomes excessively noisy as a result of performing the color adjustment processing such as white balance, as a result of excessively increasing the gain.

Therefore, in this embodiment, the lamp, CC
Even after the white balance is taken in consideration of spectral characteristics other than the filter such as D, the light amount of each band is adjusted on the light source side so that each band image has an appropriate SN characteristic. It is assumed that the band limiting filter 92 has the spectral characteristics shown in FIG.

FIG. 49 shows the illumination timing of each band and the light amount control timing at that time. At the time of normal observation in which the band limiting filter 92 is not inserted on the optical path, FIG.
9 (a), the power supply unit 10 receives a control signal from the dimming circuit 43, and controls the xenon lamp 11
And the light level control as shown in FIG. 49 (b) is performed. The reason why the light amount is reduced during the light blocking period is to reduce the heat generated from the lamp.

On the other hand, at the time of narrow-band light observation in which the band-limiting filter 92 is inserted on the optical path, the power supply unit 10 transmits the control signal from the dimming circuit 43 to the illumination timing shown in FIG. The voltage level of the driving voltage of the receiving xenon lamp 11 is controlled to perform light amount control as shown in FIG.

As described above, in the present embodiment, in addition to the effects of the third embodiment, the spectral distribution of light emitted from the light source when the voltage level of the driving voltage of the xenon lamp 11 is not controlled (see FIG. 48) ) Has spectral characteristics as shown in FIG. 50, and light amount control in which each band image has appropriate SN characteristics can be realized.

FIG. 51 is a configuration diagram showing a configuration of an endoscope apparatus according to the fifth embodiment of the present invention.

Since the fifth embodiment is almost the same as the third embodiment, only different points will be described, and the same components will be denoted by the same reference numerals and description thereof will be omitted.

As shown in FIG. 51, in the electronic endoscope 3 of this embodiment, a color chip 101 is arranged on the front surface of the CCD 2 to constitute a color CCD 2a, and the simultaneous endoscope apparatus 1 is constructed. I have. The color imaging signal from the color CCD 2a is converted into color image data by the A / D converter 24, color-separated by the color separation circuit 102, input to the white balance circuit 25, and input to the memory 103 via the selector 26. After that, the image processing circuit 30 performs interpolation processing and the like, and then performs desired image processing.

The light source device 4 includes a band limiting filter 92 having multi-peak band pass characteristics (see FIGS. 38, 40, and 44). The band limiting filter 92 receives an instruction signal from the mode switch 41. Based on the control signal from the mode switching circuit 42, the filter is moved into and out of the optical path by the filter moving motor 87.

In the present embodiment configured as described above,
By inserting the band limiting filter 92 into the optical path, the spectral characteristics of the image captured by the CCD 2 via the color chip 101 become a discrete narrow band image (see FIG. 39).
By performing image processing on the narrow band image, the present embodiment can provide the same effect as that of the third embodiment.

FIG. 52 is a configuration diagram showing a configuration of an endoscope apparatus according to the sixth embodiment of the present invention.

Since the sixth embodiment is almost the same as the fifth embodiment, only different points will be described, and the same components will be denoted by the same reference numerals and description thereof will be omitted.

In this embodiment, as shown in FIG.
A light source device 112 for narrowband observation is provided separately from the light source device 111 for normal observation.

The light source device 111 has a xenon lamp 11 as illumination light emitting means, and white light from the xenon lamp 11 enters a light guide 15 of an electronic endoscope 3 having a color CCD 2 a via a diaphragm device 13. The light is incident on the surface.

The light source device 112 includes an extra-high pressure mercury lamp 113 as illumination light emitting means. The light from the extra high pressure mercury lamp 113 is dimmed by the diaphragm device 13, and is electronically viewed through the band limiting filter 92. The light is incident on an incident surface of an illumination probe 114 inserted through a treatment tool channel (not shown) of the mirror 3.

Here, the aperture devices 13 of the light source devices 111 and 112 are controlled by the dimming circuit 43 based on the control signal from the mode switching circuit 42 and the dimming control parameters from the dimming control parameter switching circuit 44. It has become so.

In the present embodiment, during normal observation, the aperture device 13 of the light source device 111 is set to be bright, and the aperture device 13 of the light source device 112 is set to be dark or shut off.

Further, at the time of narrow-band light observation, the light source device 11
The second aperture device 13 is set brighter, and the aperture device 13 of the light source device 111 is set darker or shut off.

By setting the respective diaphragm devices 13 in this manner, narrow-band light is emitted from the emission surface of the illumination probe 114 during narrow-band light observation, so that the present embodiment is different from the fifth embodiment in that Similar effects can be obtained.

FIGS. 53 to 57 relate to the seventh embodiment of the present invention. FIG. 53 is a diagram showing the configuration of an endoscope apparatus, and FIG. 54 shows an example of the spectral distribution of the xenon lamp of FIG. FIG. 55 is a diagram showing an example of the spectral distribution of the ultra-high pressure mercury lamp of FIG. 53, FIG. 56 is a configuration diagram showing the configuration of the light mixing unit of FIG. 53, and FIG. 57 is narrow band observation by the light mixing unit of FIG. FIG. 6 is a diagram illustrating an example of a spectral distribution of light emitted from the light source device at the time.

Since the seventh embodiment is almost the same as the third embodiment, only different points will be described, and the same components will be denoted by the same reference numerals and description thereof will be omitted.

In the light source device 3 of this embodiment, as shown in FIG. 53, two lamps, a xenon lamp 11 having a relatively broad spectral distribution as shown in FIG. 54, and a light path orthogonal to the xenon lamp 11 An ultra-high pressure mercury lamp 113 having a plurality of emission line spectra as shown in FIG.
And a light mixing unit 121 that mixes respective lights from the super-high pressure mercury lamp 113 with the light. Then, the light mixed by the light mixing unit 121 is supplied to the electronic endoscope 3 via the diaphragm device 13 and the rotary filter 91.

As shown in FIG. 56, the light mixing section 121
Aperture 12 for adjusting the amount of light from xenon lamp 11
2, a diaphragm 123 for adjusting the amount of light from the ultra-high pressure mercury lamp 113, a diaphragm 122 and a half mirror 124 for combining light passing through the diaphragm 123 and outputting the light on the optical path of the diaphragm device 13 and the rotary filter 91, and a mode switch. An aperture control circuit 125 controls the aperture 122 and the aperture 123 based on a control signal from the circuit 42.

At the time of narrow-band observation, the stop control circuit 125 closes the stop 122 in front of the xenon lamp 11 and opens the stop 123 in front of the ultra-high pressure mercury lamp 113,
The illumination light emitted from the light mixing unit 121 is light having spectral characteristics equivalent to those of the ultra-high pressure mercury lamp 113. The light is transmitted through a rotating filter 91 of R1G1B1 to irradiate the living tissue with RGB narrow band sequential light as shown in FIG.

On the other hand, during normal observation, the aperture control circuit 12
By closing the stop 122 on the front of the ultra-high pressure mercury lamp 113 and opening the stop 123 on the front of the xenon lamp 11 by 5, the living tissue is irradiated with RGB plane-sequential light enabling natural color reproduction.

As described above, the present embodiment can provide the same effects as those of the third embodiment.

When obtaining intermediate illumination light between the xenon lamp 11 and the ultra-high pressure mercury lamp 113, the opening characteristics of the apertures on the front of both lamps are adjusted so that the characteristics of both lamps correspond to the aperture ratio of the apertures. Illumination light that is mixed at a ratio and has spectral characteristics different from those of both lamps can be obtained.

Further, the dimming control parameter changes the dimming table according to the mode switching, and the dimming circuit 4
The operation of step 3 is changed to compensate for a change in the illumination light amount due to a change in the illumination light spectral distribution. As a result, even when switching to the illumination light spectral distribution according to the purpose, such as observing the mucosal surface structure in detail, it is possible to always observe an image with appropriate brightness.

FIG. 58 is a configuration diagram showing a configuration of an endoscope apparatus according to the eighth embodiment of the present invention.

Since the eighth embodiment is almost the same as the first embodiment, only different points will be described, and the same components will be denoted by the same reference numerals and description thereof will be omitted.

In this embodiment, as shown in FIG. 58, a dedicated narrow-band light source device 131 for supplying narrow-band plane-sequential light to the electronic endoscope 3 and a narrow-band light source device 131 picked up by the electronic endoscope 3 are provided. Narrow-band video processor 13 for processing band-plane sequential light
2 is a narrow-band observation endoscope apparatus.

The narrow-band rotation filter 133 provided in the light source device 131 includes an R2 filter 14r2, a G2 filter 14g2, and a B2 filter 14b2 (see FIG. 4) for generating narrow-band RGB plane sequential light.

As described above, also in the present embodiment, narrow band observation using narrow band surface sequential light becomes possible.

Further, the narrow-band light source device 131 having the narrow-band rotation filter 133 is used for the narrow-band video processor 1.
When connected to 32, the control circuit 17 of the narrow-band light source device 131 outputs information on the type of the illumination light spectral characteristic of the narrow-band light source device 131 to the dimming control parameter switching circuit 44 as an identification signal. The correspondence between the identification signal and the control parameter is recorded in advance in the dimming control parameter switching circuit 44 in the form of a correspondence table, and an appropriate control signal is output to the dimming circuit 43 based on the correspondence table. In addition, dimming control according to the illumination light spectral characteristic can be performed.

FIGS. 59 and 60 relate to the ninth embodiment of the present invention. FIG. 59 is a configuration diagram showing the configuration of an endoscope apparatus, and FIG. 60 is attachable to the tip of the electronic endoscope of FIG. FIG. 3 is a diagram illustrating an adapter having a wide band-limiting filter.

Since the ninth embodiment is almost the same as the first embodiment, only different points will be described, and the same components will be denoted by the same reference numerals and description thereof will be omitted.

In this embodiment, as shown in FIG. 59, an electronic endoscope 151 for normal observation, a light source device 152 for supplying field sequential light for normal observation to the electronic endoscope 151, and an electronic endoscope An endoscope device 154 including a video processor 153 that performs signal processing on an image pickup signal from the image sensor 151, and an endoscope device 155 for narrowband light observation separately from the endoscope device 154.
It is comprised including. Here, the light source device 152 includes the xenon lamp 11 and the aperture device 13 and the R1 filter 14.
r1, a G1 filter 14g1, and a B1 filter 14b1.

The narrow-band light observation endoscope apparatus 155 includes a small-diameter electronic endoscope 156 inserted into the treatment instrument channel of the electronic endoscope 151, and a narrow-diameter electronic endoscope 156 which transmits narrow-band surface sequential light.
And a video processor 158 that performs signal processing on image signals from the small-diameter electronic endoscope 156. The light source device 152 includes an ultrahigh-pressure mercury lamp 113 and a diaphragm device 13 and an R2 filter 14r2, G2
A rotary filter 160 on which the filter 14g2 and the B2 filter 14b2 are arranged.

The normal observation is performed using the endoscope apparatus 154, and the narrow-band light observation is performed using the endoscope apparatus 155 for narrow-band light observation.
This is performed using

In the present embodiment, the same effects as in the first embodiment can be obtained.

The endoscope device 155 for narrowband light observation
Can be connected to a normal endoscope.

Further, an adapter 171 having a band limiting filter 170 as shown in FIG. 58 may be attached to the tip of the electronic endoscope 151. Thereby, the endoscope device 1
Even with the use of 54, narrow-band light observation can be performed.

Although FIG. 60 shows an example in which the adapter 171 having the band limiting filter 170 attached to the front surface of the objective optical system 21 is attached, the band limiting filter 170 may be attached to the front surface of the illumination lens 172.

[0122]

As described above, according to the present invention, there is an effect that tissue information at a desired deep portion near the tissue surface of a living tissue can be obtained.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a configuration of an endoscope apparatus according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram showing a configuration of a rotary filter of FIG. 1;

FIG. 3 is a diagram illustrating spectral characteristics of a first filter set of the rotary filter of FIG. 2;

FIG. 4 is a diagram illustrating spectral characteristics of a second filter set of the rotary filter of FIG. 2;

5 is a diagram showing a layered structure of a living tissue observed by the endoscope apparatus of FIG. 1;

FIG. 6 is a view for explaining how illumination light from the endoscope apparatus shown in FIG. 1 arrives in a layer direction of a living tissue;

FIG. 7 is a view showing each band image by plane-sequential light transmitted through the first filter set of FIG. 3;

FIG. 8 is a view showing each band image by plane-sequential light transmitted through the second filter set of FIG. 4;

FIG. 9 is a view for explaining dimming control by the dimming circuit of FIG. 1;

FIG. 10 is a diagram showing spectral characteristics of a first modification of the second filter set of the rotary filter in FIG. 2;

FIG. 11 is a diagram illustrating spectral characteristics of a second modification of the second filter set of the rotary filter of FIG. 2;

FIG. 12 is a diagram illustrating spectral characteristics of a third modification of the second filter set of the rotary filter of FIG. 2;

FIG. 13 is a diagram showing spectral characteristics of a fourth modification of the second filter set of the rotary filter of FIG. 2;

FIG. 14 is a diagram showing a first example of a spectral distribution of the xenon lamp of FIG.

FIG. 15 is a diagram showing the spectral characteristics of a fourth modified example of the second filter set of the rotating filter in the case of the spectral distribution of the xenon lamp in FIG. 14;

FIG. 16 is a diagram illustrating spectral characteristics of living tissue illumination light according to a fourth modification of the second filter set in FIG. 14;

FIG. 17 is a diagram showing a second example of the spectral distribution of the xenon lamp of FIG.

18 is a diagram showing an example of the spectral sensitivity characteristics of the CCD in FIG.

19 is a diagram illustrating a second example of the second filter set of the rotary filter when the spectral distribution of the xenon lamp is the second example and the spectral sensitivity characteristic of the CCD is that of FIG. 18; FIG. Figure showing

FIG. 20 is a diagram showing spectral characteristics of a fifth modification of the second filter set in which the neutral density filter of FIG. 19 is deposited.

FIG. 21 is a configuration diagram showing a configuration of a first modification of the light source device of FIG. 1;

FIG. 22 is a configuration diagram showing a configuration of a dimming rotation filter of FIG. 21;

FIG. 23 is a configuration diagram showing a configuration of a second modification of the light source device in FIG. 1;

FIG. 24 is a diagram showing the dimming characteristics of a first dimming filter constituting the dimming filter of FIG. 23;

FIG. 25 is a diagram showing the dimming characteristics of a second dimming filter constituting the dimming filter of FIG. 23;

FIG. 26 is a diagram showing the dimming characteristics of the dimming filter of FIG. 23;

FIG. 27 is a diagram showing an example showing detailed spectral characteristics of a second filter set of the rotary filter of FIG. 2;

FIG. 28 is a diagram illustrating spectral characteristics of a sixth modification of the second filter set of the rotary filter in FIG. 2;

FIG. 29 is a diagram showing a configuration of a main part of a modification of the video processor of FIG. 1;

FIG. 30 is a first diagram illustrating the operation of the video processor in FIG. 29;

FIG. 31 is a second diagram illustrating the operation of the video processor in FIG. 29;

FIG. 32 is a diagram showing a seventh modification of the second filter set of the rotary filter of FIG. 2;

FIG. 33 is a diagram showing the spectral characteristics of a seventh modification of the second filter set shown in FIG. 32;

FIG. 34 is a configuration diagram showing a configuration of an endoscope apparatus according to a second embodiment of the present invention.

FIG. 35 is a configuration diagram showing the configuration of the rotary filter of FIG. 34;

FIG. 36 is a diagram showing the spectral characteristics of the color chip of FIG. 34;

FIG. 37 is a configuration diagram showing a configuration of an endoscope apparatus according to a third embodiment of the present invention.

FIG. 38 is a diagram showing bandpass characteristics of the band limiting filter of FIG. 37;

FIG. 39 is a view showing the spectral characteristics of discrete narrow-band plane-sequential light by the band-limiting filter of FIG. 38;

FIG. 40 is a diagram showing bandpass characteristics of a first modification of the band-limiting filter shown in FIG. 37;

FIG. 41 is a diagram showing spectral characteristics of discrete narrow-band plane-sequential light by the band-limiting filter of FIG. 40;

FIG. 42 is a diagram showing bandpass characteristics of a second modification of the bandpass filter shown in FIG. 37;

FIG. 43 shows an example of the spectral characteristics of the xenon lamp of FIG. 37.

FIG. 44 is a diagram showing band-pass characteristics of a third modification of the band-limiting filter shown in FIG. 37 when the xenon lamp has spectral characteristics shown in FIG. 43;

FIG. 45 is a configuration diagram showing a configuration of a modification of the light source device of FIG. 37;

FIG. 46 is a diagram showing a configuration of a dimming rotation filter of FIG. 45;

FIG. 47 is a configuration diagram showing a configuration of an endoscope apparatus according to a fourth embodiment of the present invention.

48 is a diagram showing an example of the spectral distribution of light emitted from the light source device during normal observation in FIG. 47.

49 is a diagram showing the illumination timing of each band by the power supply unit in FIG. 47 and the light amount control timing at that time.

50 is a diagram showing an example of the spectral distribution of light emitted from the light source device during narrow-band observation by the power supply unit in FIG. 47.

FIG. 51 is a configuration diagram showing a configuration of an endoscope apparatus according to a fifth embodiment of the present invention.

FIG. 52 is a configuration diagram showing a configuration of an endoscope apparatus according to a sixth embodiment of the present invention.

FIG. 53 is a configuration diagram showing a configuration of an endoscope apparatus according to a seventh embodiment of the present invention.

54 shows an example of the spectral distribution of the xenon lamp in FIG. 53.

FIG. 55 is a view showing an example of the spectral distribution of the extra-high pressure mercury lamp of FIG. 53.

FIG. 56 is a configuration diagram showing the configuration of the light mixing unit in FIG. 53;

FIG. 57 is a diagram showing an example of a spectral distribution of light emitted from the light source device at the time of narrow-band observation by the light mixing unit in FIG. 56.

FIG. 58 is a configuration diagram showing a configuration of an endoscope apparatus according to an eighth embodiment of the present invention.

FIG. 59 is a configuration diagram showing a configuration of an endoscope apparatus according to a ninth embodiment of the present invention.

60 is a diagram showing an adapter having a band-limiting filter that can be attached to the tip of the electronic endoscope in FIG. 59.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Endoscope apparatus 2 ... CCD 3 ... Electronic endoscope 4 ... Light source apparatus 5 ... Observation monitor 6 ... Image filing apparatus 7 ... Video processor 10 ... Power supply unit 11 ... Xenon lamp 12 ... Heat ray cut filter 13 ... Aperture apparatus 14 ... Rotating filter 15 ... Light guide 16 ... Condenser lens 17 ... Control circuit 18 ... Rotary filter motor 19 ... Mode switching motor 19 20 ... CCD drive circuit 21 ... Objective optical system 22 ... Amplifier 23 ... Process circuit 24 ... A / D conversion Unit 25 White balance circuit 26 Selector 27, 28, 29 Simultaneous memory 30 Image processing circuit 31, 32, 33 D / A circuit 34 Encoding circuit 35 Timing generator 41 Mode switch 42 Mode Switching circuit 43: dimming circuit 44: dimming control parameter switching circuit

Claims (4)

[Claims] 1. An endoscope having an illumination light supply unit for supplying illumination light including a visible light region, an imaging unit for irradiating the illumination light to a subject and imaging the subject by return light, and An endoscope apparatus comprising: a signal processing unit that performs signal processing on an image pickup signal, wherein at least one of a plurality of wavelength ranges of the illumination light is limited, and a band image of a discrete spectral distribution of the subject is formed. An endoscope apparatus comprising: a band limiting unit that forms an image on an imaging unit on an optical path from the illumination light supply unit to the imaging unit. 2. The apparatus according to claim 1, wherein the illumination light supply unit includes a light amount control unit that controls a light amount of the illumination light for each of the wavelength ranges according to a restriction of the band limitation unit. The endoscope apparatus according to claim 1. 3. An illuminating light emitting unit that emits illuminating light including a visible light region, and a band limiting unit that limits at least one of a plurality of wavelength regions of the illuminating light to generate light having a discrete spectral distribution. A light source device comprising means. 4. The light source device according to claim 3, further comprising a light amount control unit that controls a light amount of the illumination light for each of the wavelength ranges according to a restriction of the band restriction unit.