JP2001170009A - Subject observing instrument - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a subject observing instrument allowing clear observation of the structure of a blood vessel, etc., running in the direction of the depth from the surface of a subject such as an organism. SOLUTION: A first filter set 28 consisting of plural filters with wide half- value width and a second filter set 29 consisting of filters R2, G2 and B2 with narrow half-value width are mounted on inner/outer circumferences of a rotary filter 27 disposed on the light passage of illumination light from a light source 24, and a filter set to be set on the light passage can be selected by a rotary filter switching mechanism 32. When the second filter set 29 is set, a subject is illuminated with light with narrow half-value width and long distance between wavelengths. Therefore, endoscopic images taken with different transmitting distances in the direction of the depth of an organism 7 are obtained and displayed on an observation monitor 6, so that the structure of a blood vessel, etc., in the direction of the depth from the surface can be observed clearly in different colors.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an object observation apparatus such as an endoscope apparatus suitable for observation of an object such as a blood vessel structure of a living tissue.

[0002]

2. Description of the Related Art Conventionally, there has been widely used an electronic endoscope apparatus which has an elongated insertion portion for inserting into a lumen, images a subject at the tip of the insertion portion, displays the subject on a monitor, and observes and treats the subject. Have been. In the conventional example, the spectral sensitivity characteristics of the electronic endoscope apparatus are set in advance with emphasis on color reproduction.

[0003] Japanese Patent Laid-Open No. 1-217415 (second
Japanese Patent No. 686089) discloses a technique in which a rotary filter is replaced in a field sequential electronic endoscope in order to obtain images of a plurality of wavelengths. In this conventional example, the main focus has been on observation of a near-infrared image and observation of a blood flow state such as hemoglobin.

[0004]

However, in the conventional endoscope apparatus and the like, it was not possible to clearly observe the vascular structure running in the depth direction near the surface of the living tissue in the body cavity.

(Object of the Invention) The present invention has been made in view of the above points, and has an object capable of clearly observing a blood vessel structure running in the depth direction near the surface of the object such as a living body. It is an object to provide an observation device.

[0006]

A first illuminating light for generating an illuminating light of a first wavelength band having a narrow half-value width which can be transmitted by a first transmission distance from a surface layer of an object in a visible light wavelength band. Generating means for generating, within the visible light wavelength band, a second illumination light having a narrow half-value width that can be transmitted by a second transmission distance from the surface layer of the subject without overlapping with the first wavelength band. A second illumination light generation unit, an imaging unit capable of imaging a subject image illuminated with the first illumination light and the second illumination light, and an image signal of the subject image based on an output signal of the imaging unit. Display means for displaying subject information images representing subject information at the first transmission distance and the second transmission distance, so that the illumination light of the first and second wavelength bands having a narrow half-value width is provided. By imaging the object illuminated by It is possible to obtain an image of an object corresponding to a state of blood vessel running in a portion having a different transmission distance, and to display the image as an object information image on the display means by combining them with different color signals or the like. Can be clearly observed.

[0007] Further, R illumination light generating means for generating illumination light in the R wavelength band of the visible light wavelength band, and G illumination light for generating illumination light in the G wavelength band in the visible light wavelength band. Generating means, B illumination light generating means for generating illumination light in the B wavelength band of the visible light wavelength band, and R, G, B wavelength bands of the visible light wavelength band. A first illuminating light generating means for generating illuminating light of a first wavelength band having a FWHM narrower than the FWHM and capable of transmitting a first transmission distance from the surface of the subject; Of which
It has a half width smaller than the half width of each of the R, G, and B wavelength bands, and does not overlap with the first wavelength band.
Second illumination light generating means for generating illumination light of a second wavelength band that can be transmitted by a second transmission distance from the surface layer of the subject; and R, G, and B of the visible light wavelength band. Having a half width narrower than the half width of each wavelength band;
And third illumination light generating means for generating illumination light of a third wavelength band that can be transmitted by a third transmission distance from the surface layer of the subject without overlapping with the second wavelength band;
Capable of capturing a first visible object image illuminated with illumination light in the G and B wavelength bands and a second visible object image illuminated with illumination light in the first, second, and third wavelength bands Based on an output signal of the video signal processing unit, the video signal processing unit generating the first visible subject image and the second visible subject image based on an output signal of the imaging unit, Display means for displaying the first visible subject image and the second visible subject image, thereby providing the first visible object image when illuminated with illumination light in the R, G, and B wavelength bands. A visible subject image can be obtained, and a second subject image illuminated with illumination light of the first, second, and third wavelength bands having a narrow half width can be obtained. Specimen images are obtained from the blood vessel travel of the part with different transmission distances. It is the subject image to the child or the like,
By displaying them on display means by combining them with different color signals or the like, it is possible to clearly observe portions having different transmission distances.

[0008] Further, R illumination light generating means for generating illumination light in an R wavelength band in the visible light wavelength band, and G illumination light for generating illumination light in a G wavelength band in the visible light wavelength band. Generating means, B illumination light generating means for generating illumination light in the B wavelength band of the visible light wavelength band, and half of each of the R, G, B wavelength bands in the visible light wavelength band. A first illuminating light generating means for generating illuminating light of a first wavelength band having a half width smaller than the value width and capable of transmitting a first transmission distance from the surface layer of the subject; , Having a half-width narrower than the half-width of each of the R, G, and B wavelength bands, and capable of transmitting by a second transmission distance from the subject surface layer portion without overlapping the first wavelength band. 2
A second illuminating light generating means for generating illuminating light of a wavelength band of the following; and a half-width narrower than a half-width of each of the wavelength bands of R, G, and B in the visible light wavelength band; 1
And third illumination light generating means for generating illumination light of a third wavelength band that can be transmitted by a third transmission distance from the surface layer of the subject without overlapping with the second wavelength band;
Capable of capturing a first visible object image illuminated with illumination light in the G and B wavelength bands and a second visible object image illuminated with illumination light in the first, second, and third wavelength bands Based on the output signal of the imaging means, the video signal processing means for generating the first visible subject image and the second visible subject image, based on the output signal level of the imaging means, The first video signal generated by the video signal processing means;
Display means for switching and displaying the visible object image and the second visible object image,
First case when illuminated with illumination light in the R, G, B wavelength bands
Or a second subject corresponding to a state of blood vessel running in a portion having a different transmission distance by illuminating with illumination light of the first, second, and third wavelength bands each having a narrow half-value width. Images can be switched and displayed.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) FIGS. 1 to 7 relate to a first embodiment of the present invention, and FIG. 1 shows an electronic endoscope apparatus according to a first embodiment of the subject observation apparatus of the present invention. 2 shows the detailed configuration of FIG. 1, FIG. 3 shows the configuration of two filter sets provided in the rotary filter, and FIG. 4 shows the configuration of each filter constituting the two filter sets of FIG. FIG. 5 shows a configuration of an image processing unit, FIG. 6 shows a schematic explanatory view of the operation of the present embodiment, and FIG. 7 shows a schematic table of a monitor screen when a living body is observed. An example is shown.

A first object of the present embodiment is to provide an electronic endoscope apparatus capable of clearly observing a blood vessel structure running in the depth direction from the vicinity of the surface of a living body to the inside thereof. However, still another object is that, in a field sequential type electronic endoscope apparatus, when the spectral transmittance characteristic of the rotation filter is switched, the change of the image processing content is changed according to the switching, and the rotation filter is changed. It is an object of the present invention to provide an electronic endoscope apparatus which can obtain an endoscope image which can be easily observed in each observation mode in accordance with the switching of.

As shown in FIG. 1, an electronic endoscope apparatus 1A according to a first embodiment for forming an object observation apparatus of the present invention includes an electronic endoscope 2 provided with an image pickup means, and an electronic endoscope. An observation device 5 including a light source unit 3 as an observation illumination light supply unit for supplying illumination light to the illumination light transmission unit 2 and a signal processing unit 4A for performing signal processing on an imaging unit, and output from the observation device 5. And an observation monitor 6 for displaying an image signal.

The electronic endoscope 2 has an elongated insertion portion 8 inserted into a living body (subject) 7, an operation portion 9 formed at the rear end of the insertion portion 8, and extends from the operation portion 9. The connector 11 provided at the end of the universal cable 10 can be detachably connected to the observation device 5.

The insertion portion 8 has a distal end portion 12 and the distal end portion 12.
A bending portion 13 provided at the rear end of the
And a flexible portion (flexible portion) 14 extending from the rear end of the operating portion 9 to the front end of the operating portion 9.
By operating 5, the bending portion 13 can be bent.

A light guide 16 is inserted into the insertion section 8 (as shown in an enlarged view), and the connector 11 is connected to the observation device 5 to illuminate the illumination light from the light source section 3 as shown in FIG. Is supplied to the incident end face.

The light is transmitted by the light guide 16,
The light is emitted forward from the distal end surface fixed to the illumination window of the distal end portion 12 and illuminates a target site in the living body 7. The illuminated target portion is, for example, a charge-coupled device (abbreviated as CCD) 18 as a solid-state imaging device arranged at an image forming position by an objective lens 17 attached to an observation window provided adjacent to an illumination window at the distal end portion 12. And is photoelectrically converted.
The objective lens 17 and the CCD 18 form an imaging unit 19 as imaging means.

The image signal photoelectrically converted by the CCD 18 is subjected to signal processing by a signal processing unit 4A in the observation device 5 to generate a standard video signal (image signal). Is output.

A treatment tool insertion port 20 is provided near the front end of the operation unit 9. The treatment tool insertion port 20 communicates with an internal channel 21 so that a biopsy forceps or the like can be passed through the treatment tool insertion port 20. A biopsy procedure or the like can be performed by inserting a treatment tool and projecting from the distal end through the channel 21.

FIG. 2 shows the configuration of the light source unit 3 and the signal processing unit 4A as observation illumination light supply means in the observation device 5. The light source unit 3 includes an observation illumination light source 24 that generates observation illumination light that emits broadband light from ultraviolet light to infrared light. As the light source 24, a general xenon lamp, a strobe lamp, or the like can be used. The xenon lamp and the strobe lamp emit not only visible light but also a large amount of ultraviolet light and infrared light.

The observation illumination light source 24 is supplied with power to be turned on by a power supply 25. In front of the light source 24, a rotary filter 27 as shown in FIG. As shown in FIG.
It has a double structure, and two sets of filters 28 and 29 are provided on an inner peripheral portion and an outer peripheral portion.

The first filter set 28 on the inner peripheral side is composed of three filters R1, G1, and B1 for normal observation, and the second filter set 29 on the outer peripheral part is for special observation or close observation. The first filter set 28 and the second filter set 29 are manufactured with spectral transmittance characteristics according to the observation purpose, respectively.

That is, the first filter set 28 includes filters 28a, 28b, and 28c for transmitting light in the red (R1), green (G1), and blue (B1) wavelength regions for normal observation along the circumferential direction. R2, G2, B
2. Filters 29a and 29 that transmit light of each wavelength region
b, 29c are arranged.

FIG. 4 shows the first filter set 28 shown in FIG.
7 shows the spectral transmission characteristics of each filter of the second filter set 29 with respect to the wavelength. As shown in FIG. 4, the R1, G1, and B1 filters that constitute the first filter set 28 are R, G, and B, which are widely used in an ordinary plane-sequential illumination light source.
It has the same characteristics as the B filter.

On the other hand, the filters of R2, G2, and B2 constituting the second filter set 29 are different from the characteristics of the R, G, and B filters widely used in a general field sequential illumination light source, and are particularly narrow. Half width Whr, Whg, Whb
And that, for example, R2, G2, and B2 belong to the R, G, and B wavelength ranges, respectively, but the center wavelength is R
It is characterized in that the wavelength is set to be suitable for observing the blood vessel structure in the vicinity of the surface layer of the gastric mucosa from the surface layer of the gastric mucosa, as will be described later, deviating from 1, G1, B1.

That is, when the living body 7 is illuminated with the light having passed through each of the filters R2, G2, and B2, the living body 7 is transmitted through the living body 7 in the depth direction (depth distance or depth). Are set differently.

For this reason, the light passing through each filter is
The image captured in the state where the light is illuminated corresponds to the transmission distance of light of that wavelength, and by displaying them in different colors, an image can be obtained in which portions having different transmission distances are displayed in different colors. I have to.

The filter set disposed on the illumination light path by the light source 24 shown in FIG. 1 is discriminated whether the filter set is on the inner peripheral side or the outer peripheral side, and the light illuminating the observation site is determined. A filter identification circuit 31 for identification is provided. Also, a rotary filter switching mechanism 32 is provided so that an inner filter set 28 and an outer filter set 29 can be selectively set on an illumination optical axis connecting the light source 24 and the light guide 16 incident end. is there.

In the case of normal observation, the light beam P1 (indicated by a solid line in FIG. 3) from the light source 24 is opposed to the filter set 28 on the inner peripheral side, and special observation (or close observation) is performed.
In this case, the rotary filter switching mechanism 32 (shown in FIG. 1) controls the entirety of the rotary filter 27 so that the light beam P2 (shown by a two-dot chain line in FIG. 3) from the light source 24 To switch the filter set arranged on the illumination light path.

This rotary filter switching mechanism 32 is
6 and the identification circuit 31 are moved relatively to the light source 24, but the light source 24 side may be moved in the opposite direction. Further, the rotation of the motor 26 is controlled by a control circuit 33 so as to be driven.

Ri, G transmitted through the rotary filter 27
Light separated in time series into light of each wavelength region of i and Bi (i = 1 or 2) is incident on the incident end of the light guide 16, and the exit end surface on the tip end side through the light guide 16. And is emitted forward from the emission end face to illuminate an observation site or the like.

In order to identify the light illuminating the observation site, a filter identification signal F1 output from a filter identification circuit 31 provided in the light source section 3 passes through a control circuit 33 which controls the motor 26. Timing generator 3
The timing generator 34 outputs a timing signal synchronized with the filter identification signal F1 to the CCD driver 35 and the like.

The return light reflected from the subject (subject) such as the observation site by the illumination light is focused on the CCD 18 by the objective lens 17 and photoelectrically converted by the CCD 18. A drive pulse from a CCD driver 35 in the signal processing unit 4 is applied to the CCD 18 via a signal line, and an electric signal (image signal) corresponding to the image of the subject photoelectrically converted by the drive pulse is applied. It is to be read.

Therefore, the driving pulse accumulates electric charges in the CCD 18 during the opening period of the rotary filter 27 (the period during which the observation light is irradiated on the subject), and during the light shielding period (when the observation light is not irradiated on the subject). During this period, the charge stored in the CCD 18 is read. In FIG. 3, for simplicity,
The figure shows a state in which no light-shielding portion is provided. Actually, a light-shielding portion is provided in an adjacent portion such as the R1 filter and the B1 filter, and when a light beam hits the light-shielding portion, a light-shielding period is set.

The electric charge read from the CCD 18 is input as an electric signal to a preamplifier 36 provided in the electronic endoscope 2 or the observation device 5 via a signal line. The image signal amplified by the preamplifier 36 is input to a process circuit 37 and subjected to signal processing such as γ correction and white balance.
8, the signal is converted into a digital signal.

The digital image signal is, for example, red (R), green (G), and blue (B) by the selection circuit 39.
The three first memories 41a and the second memories 41a provided for the respective colors
The data is selectively stored in the memory 41b and the third memory 41c.

The first memory 41a and the second memory 41
b, the color signals of Ri, Gi, and Bi (indicated by SR, SG, and SB in FIG. 5) stored in the third memory 41c are simultaneously read and input to the image processing unit 42; Performs image processing.

The output signal from the image processing section 42 is D
The analog color signal (FIG. 2)
For simplicity, R, G, and B are converted to R, G, and B).
The signal is output to the observation monitor 6 as a B color signal, and the observation site is displayed in color by the observation monitor 6.

A rotary filter switching instruction device 45 is connected to the electronic endoscope apparatus 1A.
1 is output to the rotation filter switching mechanism 32 to switch the rotation filter 27. At the same time, an image processing change instruction signal C2 is output to the image processing unit 42 to instruct the image processing unit 42 to change the processing content.

In the signal processing section 4A of the observation device 5, a timing generator 34 for producing the timing of the entire system is provided.
4, synchronization between the circuits such as the control circuit 33, the CCD driver 35, and the select circuit 39 is established.

FIG. 5 shows a specific configuration example of the image processing section 42. Ri from the memories 41a, 41b, 41c,
Color signals SR, SG, and SB (more specifically, R1, G1, and B1) generated by imaging under illumination light of Gi and Bi.
Color signals R, G, B obtained under the illumination light of
G2, color signals R, G, obtained under the illumination light of B2
B) are R, G, and B gain adjustment units 51a and 51, respectively.
b, 51c and gain parameter changing circuit 52
The gain is adjusted by the gains set by the gain parameters Pa, Pb, and Pc from the above and output to the D / A converter 43 side.

The gain parameter changing circuit 52 applies the gain parameters Pa, Pb, Pc corresponding to the image processing change instruction signal C2 from the rotation filter switching instruction device 45 to the R, G, B gain adjusters 51a, 51b, 51c. . In this case, a gain parameter storage unit 53 is provided in the image processing unit 42, and when the image processing change instruction signal C2 is input, the gain parameter storage circuit 53 stores the gain parameter stored in the gain parameter storage unit 53 in advance. Gain parameter read request signal C to be read
3 is applied to the gain parameter storage unit 53 to output a corresponding gain parameter set C4, and the gain parameters Pa and P constituting the gain parameter set are output.
b, Pc are set to R, G, B gain adjustment units 51a, 51b, 5
1c may be applied.

Next, the operation of the present embodiment will be described. When performing normal observation, the first filter set 28 is arranged on the illumination light path and observation is performed. In this case, the white light from the light source 24 is converted to a normal R, whose characteristic is shown in FIG.
First filter set 2 having the same characteristics as G and B filters
By passing through the light 8, it becomes R, G, B field-sequential illumination light, and illuminates the living body 7 with R, G, B field-sequential illumination light.

The R, G, and B image signals (color signals) obtained by imaging the living body 7 illuminated by the R, G, and B plane-sequential illumination light with the CCD 18 are converted into digital signals, and are converted into digital signals. The data is sequentially stored in the second memory 41b and the third memory 41c.

The first memory 41a and the second memory 41
b, the R, G, and B color signals temporarily stored in the third memory 41c are simultaneously read out, input to the image processing unit 42, and subjected to image processing by the image processing unit 42.
Then, the image is converted into an analog color signal by the D / A converter 43, and an image of the living body 7 is displayed in color on the observation monitor 6. As described above, in the case of normal observation, the first observation is performed so as to cover the entire visible range so as to obtain natural color reproduction.
A filter set 28 is used.

On the other hand, in the case where the top priority is to obtain an image of the surface unevenness of the living mucous membrane or a blood vessel construction image in the proximity of the living body 7 (in the close observation mode), the second filter set 29 is used. Observation is made available.

In this case, the user operates, for example, a close-up observation mode switch which constitutes the rotary filter switching instruction device 45, and when the switch is turned on, the rotary filter switching mechanism 32 outputs a rotary filter switching instruction signal C.
1 is output and the rotation filter 27 is switched, and at the same time, an image processing change instruction signal C2 is output to the image processing unit 42 to instruct the image processing unit 42 to change the processing contents.

That is, when the rotary filter switching instruction signal C1 is input, the rotary filter switching mechanism 32 moves the rotary filter 27 and the like upward in FIG. P2 is the second filter set 2
The movement is set so as to hit the 9 side, and when set in this state, the filter identification circuit 31 detects the movement and the rotation filter switching operation ends.

In this close observation mode, the light transmission characteristics of the filters R2, G2 and B2 are R as shown in FIG.
1, half widths Whr, Wh smaller than those of G1, B1
g, Whb, and the luminance level of the obtained signal also decreases, so that the image processing change instruction signal C2 is output to the image processing unit 42 in conjunction with the switching to the second filter set 29. And R, G, B gain adjustment units 51a, 5
The gains 1b and 51c are made larger than in the normal observation mode so that an image suitable for observation can be obtained.

In the case of the close-up observation mode in this embodiment, an image (component image) obtained under illumination by each of the filters R2, G2, B2 is used rather than obtaining an image in a state of white balance. ) Are displayed so as to be easily recognizable. For example, the gain values are set so that the luminance levels of the obtained component images are substantially the same, or displayed in different colors. , Easy to identify when displayed in different colors (easy to identify in consideration of human recognition function for color)
The gain value is set so that the brightness level is obtained.

When the observation is performed in the close-up observation mode in this manner, the observation becomes suitable for observing the cross-sectional structure of the living mucous membrane as shown in FIG. The cross section of a living mucosa, such as the stomach mucosa, which is rich in blood vessels in the depth direction is generally shown in FIG.
(A). Due to the uneven structure on the surface, there are capillaries near the surface layer, blood vessels slightly deeper than the capillaries, and a deeper deep blood vessel network. As a point for observing the living mucous membrane, it is desirable to obtain an observation image that can show such a state of the blood vessel construction. And, by observing the state of vascular construction, early detection of lesions such as cancer becomes easy.

The manner in which the light observing the living body 7 in which the blood vessel is traveling in the depth direction by the light for observing the living body 7 will be described. As shown in FIG. 6B, for example, the shorter the wavelength of visible light (blue light), the lower the depth of penetration into the living body. The longer the wavelength (from green to red), the deeper the organism 7 reaches. In other words, when observed with short-wavelength light, information up to a relatively shallow part of the mucous membrane is reflected in the (imaged) image. Conversely, with short-wavelength light, up to the deep layer where there are many thick blood vessels, short-wavelength light Is not deepened, so the thick blood vessels are not reflected in the image. Therefore, in order to observe the deep side, it is necessary to observe with light of a long wavelength having a deeper depth.

Each of the R1, G1, and B1 filters of the first filter set 28 for normal observation realizes natural color reproduction, so that each band is broadened so as to cover the visible region as shown in FIG. The half width is also wide.
In the case of this characteristic, light of a wide wavelength range is mixed with light of B1 which is short-wavelength light, and from light with a small depth to light with a medium depth in FIG. Observe at the same time. As a result, the B image reflects the mixture of the capillaries near the surface layer and the blood vessels near the middle feeding, and these are mixed as the same signal.

On the other hand, the B2 light of the second filter set 29 having the narrow half-value width Whb has a narrow wavelength range included in the B2 light, and as a result, compared with the B1 light having the broad characteristic. As a result, the ratio of light having a small depth of penetration into the living body 7 increases, so that the image observed with B2 light improves the structure on the surface and the contrast of the capillary network. It becomes easier to observe.

R1 and G of the first filter set 28 in FIG.
1, B1 filter and R2 of the second filter set 29,
It is clear from the comparison of the graphs of the spectral characteristics of the G2 and B2 filters that the center wavelength is adjusted by the narrow half widths Whr, Whg, and Whb of each filter in the close observation mode, and the bands are separated without overlapping each other. It is set.

The bandwidth or half-value width Whg of G2
Is narrower than G1 and is separated from the band of B2 on the wavelength axis, so that the half-value width Whg of the wavelength included in G2 is limited to be narrow, as in the case of B2 described above, and the difference from the image due to B2 is clearer. In other words, the surface structure and the capillaries are not reflected in the image based on G2, but instead the blood vessel construction image near the middle layer is more remarkably reflected.

The bandwidth or half width Whr of R2 is
Is made narrower than R1 and separated from G2 on the wavelength axis by the same effect, and the image by R2 reflects only deep deep blood vessels. R2, G2, B2
An image obtained by imaging using each band is processed in substantially the same manner as in the case of the normal observation mode except that the gain adjustment in the image processing unit 42 is different. Is displayed in color.

In this case, the information in the depth direction of the blood vessel construction becomes a color difference, and these are combined and displayed in color. Unlike the normal observation mode, the information is reproduced more remarkably. That is, the capillary network near the surface layer is reproduced yellow (because only B is absorbed and G and R are colored), the blood vessel network near the middle layer (magenta to red), and the thick blood vessels near the deep layer are more bluish.

Therefore, on the monitor screen of the monitor 6 for observation, as schematically shown in FIG. 7, the blood vessel structures running at different depths are displayed in different colors. The running state of blood vessels can be clearly understood.

As described above, in the close observation mode, unlike the broad RGB characteristics, the half width is narrower.
By separating the bands on the wavelength axis, it is possible to obtain an image in which the running state of the blood vessel in the depth direction is more remarkably reflected.

As described above, according to the present embodiment, an endoscope image suitable for normal observation can be obtained, and the state of blood vessel construction in the depth direction can be known by switching the filter set. Can also be obtained.

As a first modification of the second filter set 29, for example, a filter set having characteristics as shown in FIG. 8 may be used. In the first modified example, for example, the filter G2 in the second filter set 29 of FIG. 4 is used as a filter R2, and filters G2 and B2 having a narrow half-value width are provided on the shorter wavelength side than the filter R2.

The filter G2 is on the slightly longer wavelength side than the filter G2 in FIG. 4, and the filter B2 is the filter B2 in FIG.
It is set to a slightly shorter wavelength side. When the second filter set 29 of the first modified example is adopted, a thick blood vessel structure near the deep layer cannot be observed, but when the blood vessel structure near the middle layer to the blood vessel structure near the middle layer is observed in more detail with different colors from each other. Suitable for.

As a second modification of the second filter set 29, for example, a filter set having characteristics as shown in FIG. 9 may be used. In this second modification, R2, G
By setting all the filters B2 and B2 in the short wavelength region, scattering and absorption changes near the surface layer of the living mucous membrane can be detected with high sensitivity. This is suitable for observing a disease state occurring near the mucosal surface such as early cancer.

Further, as a third modification, the second filter set 29 may be a filter set as shown in FIG. As shown in FIG. 10, by setting filters B2 and G2 centering on two wavelengths that exhibit the same absorption in the absorption characteristics of the living tissue and have different scattering characteristics, the emphasis is on the influence of scattering rather than the effect of absorption. Image reproduction can be obtained. This is suitable, for example, when imaging that the tissue structure is disordered and the degree of light scattering changes as the normal living mucosa becomes cancerous.

(Second Embodiment) Next, a second embodiment of the present invention will be described. In the first embodiment, the configuration of the first and second filter sets 28 and 29 is two as shown in FIG.
Although a double structure is used, a plurality of rotary filters 27a and 27b may be used as shown in FIG. In FIG. 3, each of the filter sets 28 and 29 includes three filters. However, the number of filters is not limited to three as shown in FIG. 11, and the number of filters is determined according to a desired image effect.

When a plurality of rotary filters 27a and 27b are provided as shown in FIG. 11, a plurality of rotary filters 27a and 27b are provided along the illumination optical axis as shown in FIG.
Drive devices 55a and 55b for driving the drive 7b are provided, and the drive devices 55a and 55b are connected to the rotary filter switching mechanism 32, and perform insertion / removal (insertion / retreat) movement of the rotary filters 27a and 27b to / from the illumination optical axis.

In FIG. 12, the driving devices 55a (and 55b)
Is a guide rail 54j (j = a or b), a rotary filter 27j along the guide rail 54j, a motor 26j for driving the rotary filter 27j to rotate, and a filter identification circuit 31j.
Are moved together with each other, so that the rotation filter 27j is inserted into and removed from the illumination optical axis (in FIG.
7a is set to the retracted position, and the rotary filter 27b is set to the inserted position.)

In the case of FIG.
When one of a and 27b is installed on the optical axis, the other rotary filter is retracted from the optical axis, but a plurality of rotary filters may be installed on the optical axis at the same time.

Further, by preparing a filter RGB2 having a three-peak spectral transmittance characteristic as in the modification shown in FIG. 13, this filter is not rotated, and the rotation filter switching mechanism 32 is used to shift the light onto the optical axis. By controlling only insertion and retraction, the first and second filter sets 28 shown in FIG.
The same operation and effect as in the case of using No. 29 can also be obtained.

(Third Embodiment) Next, a third embodiment of the present invention will be described. The main difference from the first embodiment is that the change of the rotation filter is performed not by the rotation filter switching instruction device 45 but by the rotation filter switching determination means, and the rotation filter is switched according to the situation and the change of the image processing contents is automatically changed. The purpose is to automate the rotation filter switching.

The electronic endoscope apparatus 1B according to the third embodiment of the present invention shown in FIG. 14 includes a rotation filter switching determination device 58 in the signal processing section 4B. The rotation filter switching determination device 58 includes an image processing unit 4 based on the CCD output signal.
The subject determination signal H that determines the observation state of the subject from 2 ′
When 1 is input, rotation filter switching is determined, a rotation filter switching instruction signal C1 is sent to the rotation filter switching mechanism 32, and an image processing change instruction signal C2 is sent to the image processing unit 42 '.

FIG. 15 shows the configuration of the image processing section 42 'in this embodiment. This image processing unit 42 'has a configuration in which a subject determination circuit 59 is provided in the image processing unit 42 of FIG. As shown in FIG. 15, the image processing unit 42 '
Includes a subject determination circuit 59 for determining the observation state of the subject.
The subject determination circuit 59 has a memory 41a.
R-, G-, and B-color signals (here, SR, SG, SB) as in FIG.

The average value of the luminance levels of the color signals SR, SG, and SB is compared with a reference level for discrimination. The subject determination signal H1 is determined by determining whether or not the subject is in the close observation state in which the subject is observed by the rotation filter switching determination device 5.
8 is output. When the average value of the luminance levels is less than the reference level, the subject determination signal H1 for the normal observation state is obtained, and when the average value is equal to or higher than the reference level, the subject determination signal H1 for the close observation state is determined. Device 5
Output 8 Other configurations are the same as those in FIG.

The rotation filter switching determination device 58 sends a rotation filter switching instruction signal C1 to the rotation filter switching mechanism 32 based on the determination result of the subject, and the image processing section 42 '.
Sends an image processing change instruction signal C2 to the CPU. Figure 2 for others
This is the same configuration as.

Next, the operation of the present embodiment will be described. When performing an endoscope inspection by inserting the insertion portion of the electronic endoscope 2 into the inside of the living body 7 and observing it at an appropriate distance from the living body 7, the average value of the color signals in that case becomes less than the reference level. , The image processing unit 42 'determines that the mode is the normal observation mode,
Can be observed in a state where the filter set 28 is arranged on the illumination light path.

When the distal end is moved to observe the affected part in close proximity to the affected part in order to observe the affected part in more detail, the average value of the color signal becomes higher than the reference level, and the image processing unit 42 ' It is determined that the observation mode has been set, and the subject determination signal H1 indicating the close observation state is output to the rotation filter switching determination device 58, and the rotation filter switching determination device 58 sends a rotation filter switching instruction signal C1 to the rotation filter switching mechanism 32. And switching is performed so that the second filter set 29 is arranged on the illumination optical path,
The image processing change instruction signal C2 is sent to the image processing unit 42 ', and the gain is adjusted to a gain suitable for observation. In the case where the automatic light control works, the switching can be performed automatically by moving faster than the response of the automatic light control.

In the above description, the filter set is switched based on the brightness of the signal captured by the CCD 18, but the filter set may be switched based on the color tone of the signal captured by the CCD 18.

For example, it is determined from the luminance distribution of the color signal that it is observing the portion where the stain is sprayed, and a filter set suitable for observing the stained image or a gain adjustment is performed. May be.

FIG. 16 shows the configuration of an electronic endoscope apparatus 1C according to a modification. In FIG. 14, when the subject determination signal H1 from the image processing unit 42 'is input to the rotation filter switching determination device 58, the rotation filter switching instruction signal C1 and the like are output based on the signal H1. However, in the modification shown in FIG. 16, for example, in the electronic endoscope 2, a magnification lens constituting the objective lens 17 is moved to the enlargement side (telephoto side) to enlarge the image more than in the normal observation state to form an enlarged observation. A mechanism is provided.

Then, by operating an enlargement movement lever provided on the operation section 9 or the like of the electronic endoscope 2 or the like, or by electrically operating the enlargement observation ratio change instructing means 60 such as an enlargement switch, the enlargement observation mechanism is provided. The zooming magnification change instruction signal and the like are output, and the zoom lens is moved to change the magnification (from normal observation).
By outputting the enlargement ratio instruction signal E1 to the rotary filter switching determination device 58 from 0, the rotation filter switching determination device 58 outputs the rotation filter switching instruction signal C1 to the rotary filter switching mechanism 32, and the proximity of the normal observation filter set. The filter set is changed to an observation filter set, and an image processing change instruction signal C2 is sent to the image processing unit 42 so as to be suitable for a filter set whose gain has been changed.

For this reason, in FIG. 16, the signal processing unit 4C has the rotation filter switching determination device 58 provided therein similarly to the case of FIG. 14, but the structure using the same image processing unit 42 as in FIG. Has become. Other configurations are the same as those of the above-described embodiment.

Also in the case of this modification, it is possible to select and set a filter set suitable for the observation state according to the observation state, and to observe with a gain setting suitable for image observation in that case. .

As another modification, semi-automatic control may be performed. For example, as shown in FIG. 2, the change from the first filter set 28 for normal observation to the second filter set 29 is manually performed by the rotary filter switching instructing device 45, but the change from the second filter set 29 to the first filter set is performed. The change to the set 28 may be automatically performed by the rotation filter switching determination device 58 (as determined by the image processing unit 42 ') as in the case of FIG.

Alternatively, automatic and manual operation may be selected and set by the rotary filter switching determining device 58 and the rotary filter switching instructing device 45. According to the present embodiment, since the operation of changing the characteristics can be automated, the trouble of the user can be simplified.

(Fourth Embodiment) Next, a fourth embodiment of the present invention will be described with reference to FIG. The present embodiment achieves the object of simplifying the white balance setting operation by realizing the operation for preparing the white balance setting value for each filter set in advance by one operation.

The electronic endoscope apparatus 1D according to the fourth embodiment shown in FIG. 17 has a signal processing section 4D provided with a rotary filter switching device 63 in a signal processing section 4A in FIG. The unit 4D receives the gain setting instruction signal Ge1 from the gain setting instruction device 64 and causes the image processing unit 42 to calculate the gain value for each filter of the first filter set 28 and store the calculated value. Instructions can be given.

In this embodiment, the image processing section 42 has gain calculating means. In the image processing unit 42, for example, the R, G, and B gain adjustment units 51a to 51c shown in FIG.
Has a function of calculating the values of the gain parameters Pa, Pb, and Pc such that the levels of the three transmitted signals match, and storing the values in the gain parameter storage unit 53. The rotary filter switching device 63 is provided with a rotary filter switching mechanism 32.
To output the filter switching instruction signal C1.

Next, the operation of the present embodiment will be described. The tip of the electronic endoscope 2 is brought close to a reference object 65 such as a standard white plate, and the gain setting instruction device 64 is operated to output the gain setting instruction signal Ge1 to the rotary filter switching device 63 to instruct the start of gain setting.

The gain setting instruction device 64 is realized by a switch or the like provided in the electronic endoscope device 1D. In response to an instruction to start gain setting from the gain setting instruction device 64, the rotation filter switching device 63 switches the setting of the rotation filter 27 to the illumination light path of the first filter set 28, and at the same time, the image processing unit 42 An appropriate gain value is calculated by a gain calculating means provided in the image processing unit 42, using a gain value corresponding to each signal obtained when the illumination is sequentially performed by the R1, G1, and B1 filters of the first filter set 28, The data is stored in the gain parameter storage unit 53 in a form corresponding to the first filter set 28.

When the setting and storage are performed in this manner, thereafter, the gain parameters stored in the gain parameter storage unit 53 are called and used, so that it is possible to obtain an observation image in a white balance state. it can.

According to the present embodiment, the filter set 2 for normal observation of the rotary filter 27 can be operated by a single instruction operation.
In the case of No. 8, the gain value in that case can be set and stored so as to white balance.

In the above, it has been described that the gain is set and stored in the white balance state in the case of the first filter set 28. However, the gain in the white balance state is similarly set in the case of the second filter set 29. It may be set and stored.

In this case, for example, when the gain setting and storage operation in a white balance state in the case of the first filter set 28 is completed, the rotation filter switching device 6
Reference numeral 3 switches the setting so that the second filter set 29 is set on the optical path, and sets and stores the gain value so as to achieve white balance as in the case of the first filter set 28.

(Fifth Embodiment) Next, a fifth embodiment of the present invention will be described with reference to FIG. The present embodiment is provided with a means for notifying the user that the spectral characteristics and the image processing content have changed, and the user can recognize that the spectral sensitivity characteristics and the image processing means have changed. It is made possible.

The electronic endoscope apparatus 1E of the fifth embodiment shown in FIG. 18 differs from the electronic endoscope apparatus 1A of FIG. 2 in that a signal processing section 4E in which a change content notification circuit 72 is provided in the signal processing section 4A. Having.

The change content notifying circuit 72 sends the rotation filter switching instruction signal C2
Is input, and image processing content change information in the case of a filter set set by switching from the image processing unit 42 is input, and the changed information is output to the input / output interface 44, for example. The change information is superimposed on the video signal and output, and the change information is displayed on the observation monitor 6, so that the user can recognize the setting state and the observation state of the apparatus 1E from the change information.

Further, even when the filing device 71 for recording an endoscope image is connected, since the change information is superimposed on the video signal, the setting state of the endoscope image recorded by the device 1E can be changed. So that you can know.
Also, the change information can be recorded from the change content notification circuit 72 to the filing device 71 as supplementary information in the header portion of the endoscope image.

Next, the operation of the present embodiment will be described. The change notification circuit 72 receiving the output from the rotation filter switching instruction device 45 causes the observation monitor 6 to display the name of the current rotation filter set. Alternatively, the spectral transmittance characteristics of the rotating filter set may be displayed.

The change notification circuit 72, which has received the current parameter setting content from the image processing unit 42, displays on the observation monitor 6 a symbol representing the content or a parameter content such as an indicator on the observation monitor 6.

When the filing device 71 or the like is used by being connected to the electronic endoscope device 1E, the change notification result is stored not only on the observation monitor 6 but also on the header of the image file.

According to the present embodiment, the user can confirm what kind of system characteristics are currently on the monitor 6 and also as image file data. By being able to confirm the state, the inspection can be performed while predicting the display function on the image based on experience.

Further, depending on the observation purpose, it is conceivable to appropriately switch the contents of the image processing together with the change of the spectral characteristics. In such a case, the change can be recognized and the change of the image processing can be dealt with.

In the above description, for example, as shown in FIG.
In the case of using two, B2, and B3 filters, four memories may be prepared, and each may be displayed in a different color on the display unit.

That is, when a plurality of filters having different transmission distances and narrow half widths are prepared, images illuminated with light passing through the filters are stored in different memories and the like, and different color signals and the like are stored. May be combined and displayed on the display means.

In the above description, for example, in the first embodiment, as a means for obtaining an image in the close-up observation mode, the case of plane-sequential illumination and plane-sequential imaging has been described. It can also be configured.

For example, the living body 7 is simultaneously illuminated with light having passed through the filters of R2, G2, and B2, and the image pickup surface of the CCD 18, for example, filters of R1, G1, and B1 (or R2,
R, which has a filter characteristic wider than the filters of G2 and B2,
G, B filters) are picked up by an electronic endoscope of a simultaneous image pickup means provided with a mosaic filter provided for each pixel, and color-separated signals are stored in first to third memories 41a to 41c in FIG.
, The same image as in the first embodiment can be obtained. It should be noted that embodiments and the like configured by combining the above-described embodiments and the like in a partial manner also belong to the present invention.

[Supplementary Notes] First illumination light generating means for generating illumination light of a first wavelength band having a narrow half-value width that can be transmitted by a first transmission distance from the surface layer of the subject within the visible light wavelength band, and the first wavelength A second illumination light generating means for generating a second illumination light having a narrow half-value width capable of transmitting a second transmission distance from the subject surface layer portion within the visible light wavelength band without overlapping with a band, An imaging unit capable of imaging a subject image illuminated by the first illumination light and the second illumination light; and a first transmission distance of the subject image and a second A display means for displaying a subject information image representing the subject information at the transmission distance of the subject.

2. R illumination light generating means for generating illumination light in an R (red) wavelength band in the visible light wavelength band, and G illumination for generating illumination light in a G (green) wavelength band in the visible light wavelength band. Light generating means, and B in the visible light wavelength band
B illumination light generating means for generating illumination light of a wavelength band of (blue), and having a half width smaller than a half width of each of the R, G, and B wavelength bands in the visible light wavelength band, First illumination light generating means for generating illumination light of a first wavelength band that can be transmitted by a first transmission distance from the surface of the subject, and each of the R, G, and B in the visible light wavelength band The illumination light of the second wavelength band having a half-width smaller than the half-width of the wavelength band of the second wavelength band that can be transmitted by a second transmission distance from the surface layer of the subject without overlapping with the first wavelength band is generated. A second illumination light generating means that has a half-width smaller than a half-width of each of the R, G, and B wavelength bands in the visible light wavelength band; A third wavelength band that can be transmitted by a third transmission distance from the surface layer of the subject without overlapping A third illumination light generation means for generating illumination light, the R, G, the first visible object image and the first illuminated with illumination light having a wavelength band of B, the second, third
Imaging means capable of imaging a second visible object image illuminated with illumination light of a wavelength band of, and the first visible object image and the second visible object based on an output signal of the imaging means Video signal processing means for generating an image, and display means for displaying the first visible subject image and the second visible subject image based on an output signal of the video signal processing means. Subject observation device.

3. R illumination light generating means for generating illumination light of an R wavelength band in the visible light wavelength band, G illumination light generation means for generating illumination light of a G wavelength band in the visible light wavelength band, B illumination light generating means for generating illumination light of the B wavelength band in the visible light wavelength band, and a half width narrower than the half width of each of the R, G, and B wavelength bands in the visible light wavelength band. A first illuminating light generating means for generating illuminating light in a first wavelength band that can be transmitted by a first transmission distance from the surface layer of the subject; and R, G in the visible light wavelength band. , B having a half-width smaller than the half-width of each of the wavelength bands, and a second wavelength band of a second wavelength band that can be transmitted by a second transmission distance from the subject surface layer without overlapping the first wavelength band. Second illumination light generating means for generating illumination light;
The visible light wavelength band has a half width smaller than the half width of each of the R, G, and B wavelength bands, and does not overlap with the first and second wavelength bands. A third illumination light generating means for generating illumination light of a third wavelength band that can be transmitted by a third transmission distance;
Imaging capable of imaging a first visible subject image illuminated with illumination light in the B wavelength band and a second visible subject image illuminated with illumination light in the first, second, and third wavelength bands Means, a video signal processing means for generating the first visible subject image and the second visible subject image based on an output signal of the imaging means, and the video based on an output signal level of the imaging means. A display unit for switching and displaying the first visible subject image and the second visible subject image generated by the signal processing unit.

4. R illumination light generating means for generating illumination light of an R wavelength band in the visible light wavelength band, G illumination light generation means for generating illumination light of a G wavelength band in the visible light wavelength band, B illumination light generating means for generating illumination light in the B wavelength band out of the visible light wavelength band, and a half that is smaller than the half width of each of the R, G, and B wavelength bands in the visible light wavelength band. First illumination light generating means having a value width and generating illumination light of a first wavelength band that can be transmitted by a first transmission distance from the surface layer of the subject; A second half band having a half width smaller than the half width of each of the wavelength bands of G and B, and being capable of transmitting a second transmission distance from the subject surface layer without overlapping the first wavelength band;
A second illuminating light generating means for generating illuminating light of a wavelength band of the following; and a half-width narrower than a half-width of each of the wavelength bands of R, G, and B in the visible light wavelength band; 1
And third illumination light generating means for generating illumination light of a third wavelength band that can be transmitted by a third transmission distance from the surface layer of the subject without overlapping with the second wavelength band;
Capable of capturing a first visible object image illuminated with illumination light in the G and B wavelength bands and a second visible object image illuminated with illumination light in the first, second, and third wavelength bands Imaging means, video signal processing means for generating the first visible subject image and the second visible subject image based on an output signal of the imaging means, and an imaging magnification by the imaging means can be changed Imaging magnification changing means, and display means for switching and displaying the first visible subject image and the second visible subject image generated by the video signal processing means based on an output of the imaging magnification changing means. A subject observation device, comprising:

[0110]

As described above, according to the present invention, out of the visible light wavelength band, the illumination light of the first wavelength band having a narrow half-value width that can be transmitted by the first transmission distance from the surface layer of the subject. The first illumination light generating means to be generated and the first half of the visible light wavelength band having a narrow half-value width capable of transmitting by the second transmission distance from the surface layer of the subject without overlapping with the first wavelength band. Second illumination light generating means for generating the second illumination light, imaging means capable of imaging a subject image illuminated with the first illumination light and the second illumination light, and an output signal of the imaging means. Display means for displaying an object information image representing the object information at the first transmission distance and the second transmission distance of the object image. The subject illuminated by the illumination light of the second wavelength band is imaged by the imaging means. By imaging, it is possible to obtain an image of the subject with respect to the state of blood vessel travel and the like of a portion having a different transmission distance, and to display them on the display means as an object information image by combining them with different color signals or the like, The portions having different transmission distances can be clearly observed.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of an electronic endoscope apparatus according to a first embodiment of a subject observation device of the present invention.

FIG. 2 is a block diagram showing a detailed configuration of FIG. 1;

FIG. 3 is a diagram showing a configuration of two filter sets provided in a rotary filter.

FIG. 4 is a diagram illustrating spectral characteristics of respective filters constituting the two filter sets of FIG. 3;

FIG. 5 is a block diagram illustrating a configuration of an image processing unit.

FIG. 6 is a schematic illustration of the operation of the present embodiment.

FIG. 7 is a diagram showing a schematic display example of a monitor screen when a living body is observed.

FIG. 8 is a diagram showing spectral characteristics and the like of filters of a second filter set in a first modification.

FIG. 9 is a diagram showing spectral characteristics and the like of filters of a second filter set in a second modification.

FIG. 10 is a diagram showing spectral characteristics and the like of filters of a second filter set in a third modification.

FIG. 11 is a diagram illustrating a configuration of a rotary filter according to a second embodiment of the present invention.

FIG. 12 is a diagram showing a configuration near a rotary filter switching mechanism in a light source unit.

FIG. 13 is a diagram illustrating spectral characteristics and the like of a three-peak filter according to a modification.

FIG. 14 is a block diagram illustrating a configuration of an electronic endoscope apparatus according to a third embodiment of the present invention.

FIG. 15 is a block diagram illustrating a configuration of an image processing unit.

FIG. 16 is a block diagram showing a configuration of an electronic endoscope device according to a modification.

FIG. 17 is a block diagram illustrating a configuration of an electronic endoscope apparatus according to a fourth embodiment of the present invention.

FIG. 18 is a block diagram illustrating a configuration of an electronic endoscope apparatus according to a fifth embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1A ... Electronic endoscope apparatus 2 ... Electronic endoscope 3 ... Light source part 4A ... Signal processing part 5 ... Observation device 6 ... Observation monitor 7 ... Biological body 8 ... Insertion part 17 ... Objective lens 18 ... CCD 19 ... Imaging part 24 ... Illumination light source 26 ... Motor 27 ... Rotary filter 28,29 ... Filter set 31 ... Filter identification circuit 32 ... Rotary filter switching mechanism 33 ... Control circuit 35 ... CCD driver 41a, 41b, 41c ... Memory 42 ... Image processing unit 45 ... Rotation Filter switching instruction device

Continued on the front page F term (reference) 2H040 BA00 BA03 CA02 CA04 CA10 CA13 GA02 GA06 GA10 GA11 4C061 AA00 BB02 CC06 DD00 GG01 LL02 MM03 NN01 NN05 NN07 QQ01 QQ09 RR04 RR14 RR17 SS09 TT04 WW01 Y13 WW08 Y13 Y02

Claims (3)

[Claims] 1. A first illumination light generating means for generating an illumination light of a first wavelength band having a narrow half-value width that can be transmitted by a first transmission distance from a surface layer of an object in a visible light wavelength band, A second illumination for generating a second illumination light having a narrow half-value width that can be transmitted by the second transmission distance from the surface layer of the subject within the visible light wavelength band without overlapping with the first wavelength band; A light generating unit; an imaging unit capable of capturing an image of a subject illuminated by the first illumination light and the second illumination light; and a first imaging unit configured to output the first image of the subject image based on an output signal of the imaging unit. Display means for displaying a subject information image representing the subject information at the transmission distance and the second transmission distance. 2. An R illumination light generating means for generating illumination light of an R wavelength band in a visible light wavelength band, and a G illumination light for generating illumination light of a G wavelength band in the visible light wavelength band. Generating means; B illumination light generating means for generating illumination light in the B wavelength band of the visible light wavelength band; and R, G, B wavelength bands of the visible light wavelength band. A first illuminating light generating means for generating illuminating light of a first wavelength band having a FWHM narrower than the FWHM and capable of transmitting a first transmission distance from the surface of the subject; Among them, it has a half width smaller than the half width of each of the wavelength bands of R, G, and B, and can transmit by a second transmission distance from the surface layer of the subject without overlapping with the first wavelength band. Second illumination light generating means for generating illumination light of a second wavelength band, the visible light wavelength The third transmission from the surface layer of the subject has a half width smaller than the half width of each of the R, G, and B wavelength bands without overlapping the first and second wavelength bands. Third illumination light generation means for generating illumination light in a third wavelength band that can be transmitted by a distance, a first visible object image illuminated with the illumination light in the R, G, and B wavelength bands; An imaging unit capable of imaging a second visible subject image illuminated with illumination light of the first, second, and third wavelength bands; and the first visible subject image based on an output signal of the imaging unit. Video signal processing means for generating the second visible subject image; and display means for displaying the first visible subject image and the second visible subject image based on an output signal of the video signal processing means. A subject observation device, comprising: 3. An R illumination light generating means for generating illumination light in an R wavelength band in the visible light wavelength band, and a G illumination light for generating illumination light in a G wavelength band in the visible light wavelength band. Generating means; B illuminating light generating means for generating illuminating light in the B wavelength band of the visible light wavelength band; and half of each of the R, G, and B wavelength bands in the visible light wavelength band. A first illuminating light generating means for generating an illuminating light of a first wavelength band having a half width smaller than the value width and capable of transmitting a first transmission distance from the surface layer of the subject; , Having a half-width narrower than the half-width of each of the R, G, and B wavelength bands, and capable of transmitting by a second transmission distance from the subject surface layer portion without overlapping the first wavelength band. Second illumination light generating means for generating illumination light of two wavelength bands, the visible light wavelength band Has a half-width smaller than the half-width of each of the wavelength bands of R, G, and B, and does not overlap with the first and second wavelength bands, and has a third transmission distance from the surface layer of the subject. A third illumination light generating means for generating illumination light of a third wavelength band that can be transmitted only by the first, a first visible object image illuminated with the illumination light of the R, G, and B wavelength bands; An imaging unit capable of imaging a second visible subject image illuminated with illumination light in the first, second, and third wavelength bands; and a first visible subject image based on an output signal of the imaging unit. Video signal processing means for generating the second visible subject image; and the first visible subject image and the second visible image generated by the video signal processing means based on an output signal level of the imaging means. Display means for switching and displaying the subject image Subject observation apparatus characterized by a.