JPH04357926A - Endoscope device - Google Patents

Abstract

PURPOSE:To obtain an endoscope which can obtain visible information by selecting an optimal wavelength area in accordance with a body to be observed, and can detect easily the color tone difference of each part of the body whose identification is difficult in the image of a general visible area. CONSTITUTION:Light from a light source 24 for light-emitting wavelength of a wide area extending from an ultraviolet area to an infrared area containing a visible area is radiated to the body through a color filter 50, by which the image of the body formed in a solid-state image pickup element 36 is subjected to photoelectric conversion, and a signal corresponding to each picture element of this solid-state image pickup element 36 is read out in a time series by synchronizing with the switching of an illuminating light by a control part 25. The output signal of this solid-state image pickup element 36 is inputted to a video signal processing part 41 consisting of a process circuit 38, a matrix circuit 39 and an encoder 40 controlled by the control part 25, respectively.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an endoscope apparatus capable of selecting an observation wavelength range depending on an object to be observed.

0002

2. Description of the Related Art In recent years, various electronic endoscopes have been proposed that use solid-state imaging devices such as charge-coupled devices (CCDs) as imaging means.

[0003]This electronic endoscope has higher resolution than a fiberscope, and it is easy to record and reproduce images, and it also facilitates image processing such as magnification and comparison of two images. has advantages.

[0004] By the way, when observing an object using an imaging device such as the electronic endoscope, especially when distinguishing between a diseased part and a normal part in a living body, it is necessary to detect (recognize) subtle differences in color tone. There is a need to. However, when the change in color tone of the observed area is subtle, detecting this subtle difference requires advanced knowledge and experience, and it takes a long time to detect it, and it takes a long time to detect it. Even with concentrated attention, it was difficult to always make appropriate decisions.

[0005] To deal with this, for example, Japanese Patent Application Laid-Open No. 1983-3
Publication No. 033 focuses on the fact that there are cases where the change in color tone is large in regions other than the visible region, for example in the infrared wavelength region, and introduces spectroscopic light having at least one infrared wavelength region in a time-series manner. The object to be observed is illuminated with light, the reflected light from the object to be observed is imaged on a solid-state imaging device and converted into an electrical signal, the electrical signal is processed according to the wavelength range, and the wavelength range is detected using a specific color signal. A technique for displaying images has been disclosed. According to this conventional example, invisible information obtained in the infrared wavelength region can be converted into visible information, and, for example, it becomes possible to quickly and easily distinguish between an affected area and a normal area.

[0006]

[Problems to be Solved by the Invention] However, in the conventional example described above, since the observation wavelength range is fixed, for example, when using infrared light, images in the general visible range cannot be obtained, and both It is difficult to compare images, and it is ineffective for objects to be observed that have characteristics in other wavelength regions.

Furthermore, for example, Japanese Patent Laid-Open No. 59-139237 discloses that fluorescence generated from a living body in response to excitation light irradiation is passed through a plurality of types of bandpass filters to take a plurality of images. A technique has been disclosed in which different color tones are assigned to each density level difference, respectively, and each is configured into a single pseudo-color image.

However, in this related art example, although it is possible to identify differences in density, it is not possible to identify differences in tone.

The present invention has been made in view of the above-mentioned circumstances.
The purpose of the present invention is to provide an endoscope device that can obtain visible information and facilitate the detection of color tone differences in various parts of an object to be observed, which are difficult to identify using images in a general visible range. .

0010

[Means for solving the problems] The endoscope device of the present invention includes:
an illumination means for illuminating with light in a wavelength range at least in which the imaging device has light reception sensitivity; a wavelength limiting means for limiting the wavelength range of the illumination light of the illumination means; and an image of a subject illuminated by the illumination means. an imaging optical system, means for obtaining a normally visible color image from an image obtained by the imaging optical system, means for obtaining an image in a wavelength range of a different combination from the visible color image, the visible color image, and the and means for selectively displaying at least one of the visible color image and images in different combinations of wavelength regions.

[0011]

[Operation] At least one of the visible color image and an image in a wavelength range different from the visible color image is selectively displayed from the images obtained by the imaging optical system.

0012

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings.

1 to 5 relate to a first embodiment of the present invention, in which FIG. 1 is a block diagram showing an endoscope device, FIG. 2 is a side view showing the entire electronic endoscope device, and FIG. 3 is a rotating diagram. FIG. 4 is an explanatory diagram showing the filter, FIG. 4 is an explanatory diagram showing the transmission characteristics of each filter of the rotary filter, and FIG. 5 is a timing chart for explaining the operation of this embodiment.

The endoscope apparatus of this embodiment is applied to, for example, an electronic endoscope 1 as shown in FIG. This electronic endoscope 1
In this case, a large-diameter operating section 3 is connected to the rear end of an elongated and flexible insertion section 2, for example. A flexible cable 4 extends laterally from the rear end of the operating section 3, and a connector 5 is provided at the tip of the cable 4. The electronic endoscope 1 is connected via the connector 5 to a control device 6 that includes a light source section and a video signal processing section. Further, a color CRT monitor 7 as a display means is connected to the control device 6.

[0015] At the distal end of the insertion portion 2, a rigid distal end portion 9 and a bendable portion 10 adjacent to the distal end portion 9 and capable of bending toward the rear are sequentially provided. Furthermore, by rotating a bending operation knob 11 provided on the operating section 3, the bending section 10 can be bent in the left-right direction or the up-down direction. Further, the operation section 3 is provided with an insertion port 12 that communicates with a forceps channel provided in the insertion section 2.

The endoscope apparatus of this embodiment is constructed as shown in FIG.

A light source 24 is provided within the control device 6 . The light source 24 is a light source that emits wavelengths in a wide range from the ultraviolet region to the infrared region, including the visible region, and can be a general halogen lamp, xenon lamp, strobe lamp, or the like. The lighting of this light source 24 is controlled by a light source lighting device 26 that is controlled by a control section 25. A color filter 50 as shown in FIG. 3 is disposed in front of the light source 24. This color filter 50 is divided into nine parts in the circumferential direction, and each divided part has red (R) light, first ultraviolet light (UV
1), first infrared light (IR1), green (G), second ultraviolet light (UV2), second infrared light (IR2), blue (B), third ultraviolet light (UV3) , filters 50a to 50i that transmit third infrared light (IR3) are arranged in this order. Further, a light shielding portion 51 is provided between each of the filters 50a to 50i.

The first to third infrared lights have different wavelength ranges, and the center wavelengths of IR1, IR2, and IR3 become longer in this order. Similarly, the first to third ultraviolet lights have different wavelength ranges, UV1 and UV2.
, UV3, the center wavelength becomes longer in this order.

The light in each wavelength range that has passed through each of the filters 50a to 50i is irradiated onto the object to be observed in time series. When the wavelength range of the illumination light is switched, a light-shielding period corresponding to the light-shielding portion 51 is provided. In this embodiment, signals from the solid-state image sensor 36 are read out during this light-blocking period.

Furthermore, in this embodiment, the solid-state image sensor 3
A selection circuit 52 is provided between the video signal processing section 6 and the video signal processing section 41. This selection circuit 52 is controlled by the control unit 25 and is configured to select the output signal of the solid-state image pickup device 36 and send it to the video signal processing unit 41 at a predetermined timing.

The selection timing of this selection circuit 52 is shown in FIGS. 5(a) to 5(e). That is, when performing observation in the visible band, the timing of R, G, and B as shown in FIG. 5(b) is
When performing observation in the ultraviolet band, select signals during readout corresponding to UV1, UV2, and UV3 illumination lights, as shown in Figure 5(c). However, when performing observation in the infrared band, signals corresponding to the illumination lights of IR1, IR2, and IR3 are selected at the time of readout, as shown in FIG. 5(d). Also,
When observing in a part of the long wavelength side of the visible region and the short wavelength side of the infrared region, as shown in Fig. 5(e), R
, IR1, and signals corresponding to the G illumination lights are selected at the time of reading.

The light transmitted through the color filter 50 and emitted is incident on the cable 4 and the light guide 33 inserted into the insertion section 2, and is guided to the distal end section 9 via the light guide 33. The light is emitted from the light distribution lens system 34 provided at the tip 9 to illuminate the object to be observed.

On the other hand, at the imaging position of the objective lens system 35 provided at the distal end 9, a solid-state image sensor 36 as an imaging means is disposed. This solid-state image sensor 36 has sensitivity in a wide wavelength range from the ultraviolet region to the infrared region, including the visible region. Further, each of the filters 50a to 50i of the color filter 50 has a transmission characteristic within a range in which the solid-state image sensor 36 has sensitivity.

The image of the object to be observed formed on the solid-state image sensor 36 is photoelectrically converted, and signals corresponding to each pixel of the solid-state image sensor 36 are converted by a driver 37 controlled by the control section 25. , are read out in chronological order in synchronization with the switching of illumination light. The output signal of this solid-state image sensor 36 is input to a video signal processing section 41 consisting of a process circuit 38, a matrix circuit 39, and an encoder 40, which are each controlled by a control section 25. The output signal of the solid-state image sensor 36 is first input to a process circuit 38. In this process circuit 38, red (R) is arbitrarily added to the output signal corresponding to the illumination light in each wavelength region.
, green (G), and blue (B) are assigned to R, G,
A B color signal is generated.

R, G, B from the process circuit 38
The color signals are input to a matrix circuit 39, and the matrix circuit 39 converts the R, G, and B color signals into, for example, NTS
A C-type luminance signal Y and color difference signals RY and BY are generated. Further, the output of this matrix circuit 39 is inputted to an encoder 40, which outputs N
A TSC video signal is generated. This video signal is then input to the color CRT monitor 7, so that the object to be observed is displayed in color.

In this embodiment configured as described above, the wavelength range to which the solid-state image sensor 36 is sensitive is divided by the color filter 50 into nine wavelength ranges UV1 to IR3. Then, by selecting one of the ultraviolet, visible, and infrared bands in the selection circuit 52, three wavelength regions are selected from among the nine wavelength regions UV1 to IR3. The combination of these three wavelength regions is the first to third ultraviolet light UV1 to UV3, each color light of red (R), green (G), and blue (B), or the first to third infrared light IR1. ~IR
It is 3. Then, the light in the selected three wavelength ranges is irradiated onto the object to be observed in a time-series manner.

The reflected light from the object to be observed corresponding to each illumination light in the selected three wavelength regions is photoelectrically converted by the solid-state image sensor 36 and read out in time series in synchronization with the switching of the illumination light.

The output signals corresponding to each illumination light of the solid-state image sensor 36 are arbitrarily assigned each color of red (R), green (G), and blue (B) by the video signal processing section 41. The video signal is then processed.

Then, the object to be observed is displayed in color using each assigned color. That is, when the selection circuit 52 selects the ultraviolet band or the infrared band, the object to be observed is displayed in pseudo color.

As described above, according to this embodiment, the object to be observed can be displayed in color by selecting any band of ultraviolet, visible, or infrared and assigning any color. The optimal observation wavelength band can be selected depending on the body. Therefore, it becomes easy to detect the difference in color tone of each part of the observed object, which is difficult to distinguish using images in a general visible range.

6 to 18 relate to a second embodiment of the present invention, in which FIG. 6 is an explanatory diagram showing an endoscope apparatus, FIG. 7 is an explanatory diagram showing a color filter, and FIG. 8 is an explanatory diagram showing a color filter. An explanatory diagram showing transmission characteristics, FIG. 9 is an explanatory diagram showing the emission characteristics of a light source, FIG. 10 is an explanatory diagram showing a band-limiting filter, FIG. 11 is an explanatory diagram showing the transmission characteristics of each filter of the band-limiting filter,
FIG. 12 is an explanatory diagram showing the transmission characteristics of each filter in the color filter of the first modification, FIG. 13 is an explanatory diagram showing the transmission characteristics of each filter in the color filter of the second modification, and FIG. 14 is an explanatory diagram showing the transmission characteristics of each filter in the color filter of the second modification. An explanatory diagram showing the transmission characteristics of the color filter of the modification example. FIG. 15 is an explanatory diagram showing the transmission characteristics of each filter of the color filter of the fourth modification example. FIG. 16 is a narrow band band-limiting filter of the first modification example. FIG. 17 is an explanatory diagram showing a band-limiting filter of a second modified example, and FIG. 18 is an explanatory diagram showing transmission characteristics of each filter of the band-limiting filter.

This embodiment is an example of an endoscope apparatus in which an external television camera is attached to the eyepiece of a fiberscope.

As shown in FIG. 6, a fiber scope 60
includes an elongated, for example, flexible insertion section 62, and a large-diameter operation section 63 is connected to the rear end of the insertion section 62. A flexible light guide cable 64 extends laterally from the rear end of the operating section 63. In addition, the operation section 6
3, an eyepiece section 65 is provided at the rear end.

[0034] Inside the insertion portion 62, a light guide 69 is provided.
is inserted, and the distal end surface of this light guide 69 is disposed at the distal end portion 66 of the insertion portion 62, so that illumination light can be emitted from the distal end portion 66. Further, the light guide cable 64 is connected to the incident end side of the light guide 69.
It is inserted into the light guide cable 64 and connected to a connector (not shown) provided at the tip of the light guide cable 64, and is connected to the control device 6 (see FIG. 2) through this connector, and the light source 24 in the control device 6 is connected to the control device 6 (see FIG. 2). The light emitted from is made to enter.

Further, an objective lens system 67 is provided at the tip 66, and at an image forming position of this objective lens system 67,
The distal end surface of the image guide 68 is arranged. The image guide 68 is inserted into the insertion section 62 and extends to the eyepiece section 65. The object image formed by the objective lens system 67 is guided to the eyepiece 65 by the image guide 68 and is observed from the eyepiece 65.

An external television camera 370 is detachably attached to the eyepiece section 65 of the fiberscope 60. This external television camera 370 is
It includes an imaging lens 371 that forms an image of the light from the eyepiece 65, and a solid-state image sensor 336 that is disposed at the imaging position of the imaging lens 371. This solid-state image sensor 336
A color filter 337 having transmission characteristics in the visible band and infrared band is provided in front of the . Further, the light emitted from the light source 24 is made to enter the input end of the light guide 69 of the fiber scope 60 through a band-limiting filter 328 that selectively transmits the visible band and the infrared band.

As shown in FIG. 7, the color filter 337 as a wavelength region dividing means disposed in front of the imaging surface of the solid-state image sensor 336 transmits different wavelength regions R0, G0, and B0. Filters 337a, 33
7b and 337c are arranged, for example, in a mosaic pattern.

In this embodiment, each of the filters 337a,
337b and 337c have double transmission characteristics, and have transmission wavelength regions in the visible band and infrared band. That is, FIG.
As shown in , the filter 337a transmits red light R in the visible band and infrared light IR3 in the infrared band, and the filter 337b transmits green light G in the visible band and infrared light IR2 in the infrared band. , the filter 337c is configured to transmit blue light B in the visible band and infrared light IR1 in the infrared band. Note that the infrared lights IR1, IR2, and IR3 have different wavelength ranges, and the center wavelengths of IR1, IR2, and IR3 become longer in the order.

In this embodiment, the transmission wavelength range of each of the filters 337a, 337b, and 337c of the color filter 337 is limited by the band-limiting filter 328 to a wavelength range that belongs to either the visible band or the infrared band. . That is, when the visible band is selected by the band-limiting filter 328, the infrared band is not illuminated.
Each filter 337a, 337b of the color filter 337
, 337c transmit B, G, and R in the visible band, respectively; on the other hand, when the infrared band is selected by the band-limiting filter 328, the visible band is not illuminated.
Each filter 337a, 37b of the color filter 337,
37c are IR1, IR2, and IR3 in the infrared band, respectively.
will be passed through. Each of the filters 337a, 33
The light transmitted through 7b and 337c is transmitted to the solid-state image sensor 33.
6, the light is received and photoelectrically converted. This solid-state image sensor 33
The signals corresponding to each pixel of 6 are input to the video signal processing section 338, and subjected to signal processing corresponding to the simultaneous method. In this video signal processing section 338, the solid-state image sensor 336
The signal corresponding to each pixel is sent to the filter 3 in front of each pixel.
The video signals are processed into types 37a, 337b, and 337c. For example, the pixel signal corresponding to the filter 337a is red (R), the pixel signal corresponding to the filter 337b is green (G), and the pixel signal corresponding to the filter 337c is blue (
Each color of B) is assigned and the video signal is processed. The video signal output from this video signal processing section 338 is input to the color CRT monitor 7 (see FIG. 2),
The object to be observed is displayed in color.

By the way, as shown in FIG. 9, the light source 24 provided in the control device 6 is a light source that emits light in a wide band of wavelengths ranging from at least the visible region to the infrared region.
A general halogen lamp, xenon lamp, etc. can be used. The lighting of this light source 24 is controlled by a light source lighting device 26 that is controlled by a control section 25. In front of the light source 24, a band limit filter 328 as a band limit means rotationally driven by a drive motor 327 is disposed. As shown in FIG. 10, this band-limiting filter 328 is divided into two parts in the circumferential direction, and each divided part has a filter 32 that transmits the visible band as shown in FIG.
8a and a filter 328b that transmits the infrared band. Therefore, the band-limiting filter 328 selectively transmits either the visible band or the infrared band of the light emitted from the light source 24. The rotation of the drive motor 327 is controlled by a motor driver 29 that is controlled by the control section 25.

The light transmitted through the band-limiting filter 328 is incident on the cable 4 and the light guide 33 inserted into the insertion section 2, guided to the distal end 9 via the light guide 33, and then The light is emitted from a light distribution lens system 34 provided at the tip 9 to illuminate the object to be observed.

On the other hand, at the imaging position of the objective lens system 35 provided at the tip 9, a solid-state image pickup device 336 as an image pickup means is provided. This solid-state image sensor 336 has sensitivity at least in the visible band and infrared band.

The other configurations are the same as in the first embodiment.

In this embodiment configured as described above, when the light source lighting device 26 is turned on by the control unit 25, the light source 24 emits light including visible light and infrared light. The light emitted from the light source 24 is selectively transmitted in the visible band or infrared band by the band-limiting filter 328. Then, the light transmitted through this band-limiting filter 328 is irradiated onto the object to be observed.

The reflected light from the object to be observed corresponding to this illumination light is transmitted through the color filter 3 disposed in front of the solid-state image sensor 336.
Each filter 337a, 337b, 33 of the color filter 337 passes through 37 and is received by the solid-state image sensor 336.
7c has transmission wavelength regions in the visible band and infrared band, and when the visible band is selected by the band limiting filter 328, each filter 337a, 337b, 337c of the color filter 337 The band-limiting filter 3 transmits visible band B, G, and R, respectively.
When the infrared band is selected by 28, each filter 337a, 337b, 337 of the color filter 337
c transmits IR1, IR2, and IR3 in the infrared band, respectively.

The light incident on the solid-state image sensor 336 is photoelectrically converted, a video signal is generated in a video signal processing section 338, and the object to be observed is displayed in color on the color CRT monitor 7. That is, the band-limiting filter 328
When the visible band is selected by , an image in the general visible range of the object to be observed is displayed. On the other hand, when the infrared band is selected by the band-limiting filter 328 , an infrared image of the object to be observed is displayed. The image of the area will be displayed in pseudo color.

As described above, according to this embodiment, by switching the band-limiting filter 328, either the visible band or the infrared band is selected depending on the object to be observed, and the object to be observed can be colored. - Can be displayed. Therefore, it is possible to select the optimum observation wavelength band according to the object to be observed, and it becomes easy to detect the difference in color tone of each part of the object to be observed, which is difficult to distinguish using images in a general visible range.

In this embodiment, the combination of color filters and band-limiting filters is not limited to that shown in the second embodiment, and may be, for example, a combination of color filters and band-limiting filters as described below.

(1) A color filter as shown in FIG. 12 may be used. Each filter 337a, 337 of the color filter 337
b and 337c are configured to transmit red light R and infrared band IR, green light G and infrared band IR, and blue light R and infrared band IR.

(2) A color filter as shown in FIG. 13 may be used. Each filter 337a, 337 of the color filter 337
b and 337c are not limited to those that transmit R, G, and B, respectively, in the visible band, as shown in FIG. 12, and for example, as shown in FIG. G) and cyan (Cy) may be transmitted.

(3) A color filter as shown in FIG. 14 may be used. The filter 337a has R and 80 in the visible band.
The filter 337 transmits a narrow band centered around 5 nm.
The filter 337c is configured to transmit G in the visible band and a narrow band centered at 805 nm, and the filter 337c is configured to transmit B in the visible band and a narrow band centered at 805 nm.

(4) A color filter as shown in FIG. 15 may be used. Each filter 337a, 337 of the color filter 337
b and 337c have transmission wavelength regions in the visible band and the ultraviolet band. That is, the filter 337a transmits the red light R and the ultraviolet light UV3 in the ultraviolet band, and the filter 337b transmits the green light G and the ultraviolet light UV2 in the ultraviolet band.
The filter 337c is configured to transmit blue light R and ultraviolet light UV3 in the ultraviolet band. Note that the ultraviolet lights UV1, UV2, and UV3 have different wavelength ranges from each other, and the center wavelengths of UV1, UV2, and UV3 become longer in this order.

(5) A band-limiting filter with a band as shown in FIG. 16 may be used. The band-limiting filter has a narrow band pass characteristic centered at 805 nm. Note that the transmission wavelength band W0 of this band-limiting filter is preferably as narrow as possible, about 40 nm or less.

(6) A band-limiting filter 351 as shown in FIG. 17 may be used. As shown in FIG. 18, each filter 351a, 351b of this band-limiting filter 351 is a filter that transmits visible band and ultraviolet band, respectively.

[0055] Also, as a band-limiting filter, ultraviolet band,
Each filter 33 of the color filter 337 is made of a filter that can selectively transmit three or more bands such as a visible band and an infrared band.
By using filters 7a, 337b, and 337c that have transmission wavelength regions in three or more selectable bands of the band-limiting filter, any observation wavelength band can be selected from among the three or more observation wavelength bands. You can also do it.

Furthermore, the selectable observation wavelength bands are not limited to those divided into ultraviolet, visible, and infrared; for example,
It can be set arbitrarily, such as setting a part of the long wavelength side of the visible region and a part of the short wavelength side of the infrared region as the observation wavelength band.

Furthermore, the band-limiting filter and the color filter may be disposed between the light source 24 and the imaging means such as the solid-state image sensor 336, and the order of arrangement can be arbitrarily determined.

Furthermore, the device is not limited to one that receives reflected light from the object to be observed, but may be one that receives light that has passed through the object to be observed.

As described above, according to this embodiment, not only the electronic endoscope 1 as shown in the first embodiment but also the commonly used fiber scope 60 can be used to detect light outside the visible light range. It becomes possible to select and observe an arbitrary wavelength range in the wavelength range including .

Other functions and effects are the same as in the first embodiment.

19 to 25 relate to a third embodiment of the present invention, in which FIG. 19 is a block diagram showing the configuration of an endoscope device, FIG. 20 is an explanatory diagram showing a color separation filter, and FIG. 21 is a color separation filter. Explanatory diagram showing the transmission characteristics of each filter, Figure 2
2 is an explanatory diagram showing the transmission characteristics of a filter inserted in the observation optical path, FIG. 23 is an explanatory diagram showing the transmission characteristics of a visible transmission filter, and FIG. 24 is an explanatory diagram showing the transmission characteristics of a near-infrared bandpass filter. 25 is an explanatory diagram showing the difference in spectral characteristics between blood mixed with ICG and blood not mixed with ICG.

In this embodiment, a power supply 40 is provided in the control device 6.
A lamp 407 is provided which is powered by 6. This lamp 407 emits light in a wide range of wavelengths from visible to infrared light. Between the lamp 407 and the entrance end of the light guide 33 of the electronic endoscope 1, there are visible transmission filters 421 that are individually inserted into and removed from the illumination optical path by a filter changer 423.
and a near-infrared bandpass filter 422 are provided. As shown in FIG. 23, the visible transmission filter 421 transmits visible light, and the near-infrared bandpass filter 4
22, as shown in FIG. 24, has a transmission characteristic of transmitting only near-infrared light. Further, the filter changer 423 is controlled by a control circuit 420.

On the other hand, an objective lens system 401 is provided at the distal end portion 9 of the electronic endoscope 1, and a solid-state image sensor 404 is provided at the imaging position of this objective lens system 401. This solid-state image sensor 404 has sensitivity at least in the visible to near-infrared light range. A color separation filter 403 is provided in front of the solid-state image sensor 404. As shown in FIG. 20, this color separation filter 403 has cyan (Cy), green (G), and yellow (Y) in the visible band.
e) Each color filter 403a, 403b, 40 that transmits
3c arranged in a mosaic pattern. Moreover, each color filter 403a, 40 of the color separation filter 403
3b and 403c, as shown in FIG. 21, have double transmission characteristics that transmit not only Cy, G, and Ye in the visible band but also infrared light.

Further, as shown in FIG. 22, a filter 402 having a characteristic of transmitting the visible band and a narrow band centered around 805 nm is provided between the objective lens system 401 and the solid-state image sensor 404. There is.

The solid-state image sensor 404 is driven by a driver 410 in the control device 6, and the read signal is amplified by a preamplifier 411 and then sent to a process circuit 41.
2, and signal processing such as γ correction, white balance, and matrix processing is performed. The video signal from this process circuit 412 is input to an NTSC encoder 413, converted to an NTSC video signal, and input to the monitor 7.

Note that the control circuit 420, driver 410, process circuit 412, NTSC encoder 4
13 are synchronized by a timing generator 415 that generates a synchronization signal for the entire system.

In this embodiment, the lamp 407 emits light in the visible to infrared range using power from the power source 406, and this light passes through the light guide 33 to the electronic endoscope 1.
The light is transmitted to the tip 9 of the camera, and is irradiated onto the subject. Then, the returned light from the object due to this illumination light is imaged by the objective lens system 401 onto the solid-state image sensor 404, and the image of the object is captured by the solid-state image sensor 404.

Here, when the filter changer 423 is driven under the control of the control circuit 420 and only the visible transmission filter 421 is inserted in the illumination optical path, the light emitted from the lamp 407 passes through the visible transmission filter 421. This visible light is then irradiated onto the subject. The return light from the subject due to this illumination light is
After passing through a filter 402 and being color-separated by a color separation filter 403, the signal is read out as a video signal by a solid-state image sensor 404. The output signal of the solid-state image sensor 404 is processed by a preamplifier 411, a process circuit 412, and an NTSC encoder 413, and a visible image is displayed in color on the monitor 7.

On the other hand, when the filter changer 423 is driven under the control of the control circuit 420 and only the near-infrared bandpass filter 422 is inserted in the irradiation optical path, the light emitted from the lamp 407 is It passes through an outer bandpass filter 422 and is converted into near-infrared light,
This near-infrared light is irradiated onto the subject. The returned light from the subject due to this illumination light enters the filter 402 and
Only a narrow band of light centered around 0.05 nm passes through this filter 402. This narrow band light is not color-separated by the color separation filter 403.
3 and is read out as a video signal by the solid-state image sensor 404. The output signal of the solid-state image sensor 404 is processed by a preamplifier 411, a process circuit 412, and an NTSC encoder 413. Then, the subject image in a narrow band centered at 805 nm is displayed on the monitor 7 as a monochrome image.

FIG. 26 shows Indo, an infrared absorbing dye.
Difference in spectral characteristics between blood mixed with cyanine green (ICG) and blood without ICG (LCG)
(attenuation rate due to contamination). As shown in this figure,
Blood spiked with ICG has a maximum absorption at 805 nm. Therefore, if ICG is mixed into the blood by intravenous injection, and a filter 402 having a bandpass characteristic centered on 805 nm, which has the maximum absorption rate, is inserted in the illumination optical path of the lamp 407, the object to be observed will be exposed to: A narrow band of light centered around 805 nm is irradiated, and an image of the object to be observed in this narrow band is observed. Light centered at 805 nm reaches deep into the mucous membrane and is absorbed in the blood vessels, so the blood vessels are observed as shadows. Therefore, the running state of blood vessels can be observed with much better contrast than when observing in other wavelength ranges.

As described above, according to this embodiment, a normal visible color image can be obtained as in the other embodiments, and
A narrowband infrared image centered at 805 nm can be obtained.

[0072] Therefore, by mixing ICG into the blood, 805
By observing a narrow band infrared image centered on nm, it becomes possible to observe submucosal blood vessels and the range of lesions deep in the mucosa, which are difficult or impossible to observe with visible light. Furthermore, when performing treatment with a YAG laser, a filter 402 having a transmission characteristic that transmits only near-infrared light centered at 805 nm in the infrared light region is provided in front of the solid-state image sensor 404, so that YAG Another advantage is that the observation screen is not disturbed by the 1060 nm laser light.

The present invention is not limited to a device that receives reflected light from an object to be observed, but may also be a device that receives light that has passed through an object to be observed.

[0074]

As explained above, according to the present invention, the endoscope apparatus of the present invention can capture a visible color image from an image obtained by an imaging optical system and a wavelength of a different combination from the visible color image. Since it is possible to selectively display at least one of the region images, it is possible to select the optimal wavelength region according to the object to be observed and obtain visible information. This has the effect that it is possible to easily detect the difference in color tone of each part of the object to be observed, which is difficult to identify.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an imaging device according to a first embodiment.

FIG. 2 is a side view showing the entire electronic endoscope device according to the first embodiment.

FIG. 3 is an explanatory diagram showing a rotary filter according to the first embodiment.

FIG. 4 is an explanatory diagram showing the transmission characteristics of each filter of the rotary filter according to the first example.

FIG. 5 is a timing chart for explaining the operation of this embodiment according to the first embodiment.

FIG. 6 is an explanatory diagram showing an endoscope apparatus according to a second embodiment.

FIG. 7 is an explanatory diagram showing a color filter according to a second example.

FIG. 8 is an explanatory diagram showing the transmission characteristics of each filter of the color filter according to the second example.

FIG. 9 is an explanatory diagram showing light emission characteristics of a light source according to a second example.

FIG. 10 is an explanatory diagram showing a band-limiting filter according to a second embodiment.

FIG. 11 is an explanatory diagram showing the transmission characteristics of each filter of the band-limiting filter according to the second example.

FIG. 12 is an explanatory diagram showing the transmission characteristics of each filter of the color filter of the first modified example of the second example.

FIG. 13 is an explanatory diagram showing the transmission characteristics of each filter of a color filter of a second modified example of the second example.

FIG. 14 is an explanatory diagram showing the transmission characteristics of a color filter of a third modified example of the second example.

FIG. 15 is an explanatory diagram showing the transmission characteristics of each filter of a color filter of a fourth modified example of the second example.

FIG. 16 is an explanatory diagram showing the transmission characteristics of a narrowband band-limiting filter of a first modified example of the second embodiment.

FIG. 17 is an explanatory diagram showing a second modified example of a band-limiting filter according to the second embodiment.

FIG. 18 is an explanatory diagram showing the transmission characteristics of each filter of the band-limiting filter according to the second example.

FIG. 19 is a block diagram showing the configuration of an imaging device according to a third embodiment.

FIG. 20 is an explanatory diagram showing a color separation filter according to a third example.

FIG. 21 is an explanatory diagram showing the transmission characteristics of each filter of the color separation filter according to the third example.

FIG. 22 is an explanatory diagram showing the transmission characteristics of a filter interposed in the observation optical path according to the third example.

FIG. 23 is an explanatory diagram showing transmission characteristics of a visible transmission filter according to a third example.

FIG. 24 is an explanatory diagram showing transmission characteristics of a near-infrared bandpass filter according to a third example.

FIG. 25: Blood mixed with ICG and I according to the third example
FIG. 2 is an explanatory diagram showing the difference in spectral characteristics of blood not mixed with CG.

[Explanation of symbols]

1...Electronic endoscope 24...Light source 25...Controller 36...Solid-state image sensor 50...Color filter

Claims (1)

[Claims] 1. Illumination means for illuminating with light in a wavelength range in which at least the light reception sensitivity of the imaging device exists; wavelength limiting means for restricting the wavelength range of illumination light of the illumination means; an imaging optical system that captures a subject image;
means for obtaining a normally visible color image from the image obtained by the imaging optical system; means for obtaining an image in a wavelength range of a different combination from the visible color image; 1. An endoscope apparatus comprising means for selectively displaying at least one image of a combination of wavelength range images.