JP4716801B2 - Endoscopic imaging system - Google Patents

Description

  The present invention relates to an endoscope imaging system that performs fluorescence imaging using an imaging element.

Conventionally, some endoscope systems perform fluorescence observation by irradiating excitation light in addition to normal endoscopic observation using visible light. In fluorescence observation, there is a method called PDD (Photodynamic Diagnosis), in which a fluorescent substance is accumulated only in a tumor portion by administration of a drug, and the tumor is irradiated with excitation light to make the tumor fluorescent and diagnose.
PDD fluoresces red when irradiated with blue excitation light. For this reason, a band pal filter is disposed as an excitation light transmission filter that transmits blue so that blue excitation light is emitted on the light source device side, and the light transmitted through the band pass filter is used as a light guide for the endoscope. Make it incident.
In this case, since the fluorescence is weaker than the excitation light, in order to obtain a fluorescence image, it is necessary to cut the excitation light on the light receiving side and transmit the fluorescence, and a cut filter is used.

However, when the excitation light is completely cut by the cut filter, the biological state other than the fluorescent part becomes invisible.
Therefore, on the light receiving side, it is necessary to create blue background illumination light so as to transmit a certain level of excitation light while maintaining a balance with fluorescence. For this reason, a part of blue illumination light as excitation light is transmitted by the cut filter.
If the amount of transmitted light with respect to the blue illumination light is not constant, the hue contrast with the fluorescent part is deteriorated, which affects the tumor discrimination. However, there are many variations in the wavelength of the filter, and there is a problem that it is difficult to keep the illumination light for the background formed by the overlapping portion of the light transmission by the combination of the two filters.
Therefore, as disclosed in German Patent DE 19909024, the wavelength of the emitted light is made constant by adjusting the angle of the band-pass filter (excitation light transmission filter) on the light source device side. .
German patent DE 19902184

However, in DE 19909024, when a plurality of endoscopes are used for a light source device, the cut filter has a characteristic variation for each endoscope, so that it is used in combination with an endoscope. In this case, it is necessary to adjust the angle of the excitation light transmission filter on the light source device side for each endoscope.
In particular, even when an endoscope imaging system such as a television camera is mounted on an endoscope, it is necessary to adjust the angle of the excitation light transmission filter on the light source device side for each endoscope. There is room for improvement.

(Object of invention)
The present invention eliminates the need for adjusting the angle of the excitation light transmitting filter on the light source device side, and enables the fluorescence observation with an appropriate hue contrast even if the filter characteristics vary. An object is to provide a mirror imaging system.

The present invention comprises light source means for generating light in the visible wavelength region including excitation light,
An excitation light transmission filter provided in the light source means and transmitting the excitation light;
An endoscope that irradiates light from the light source means and obtains an optical subject image by reflected light from the subject;
An endoscope filter that is provided in the endoscope and transmits only a part of the excitation light and transmits fluorescence;
An imaging means attached to the eyepiece of the endoscope for imaging a subject image;
Image processing means for processing and imaging the image pickup signal from the image pickup means;
In an endoscope imaging system comprising:
A combined image generating unit that is provided in the image processing unit and generates a combined image by a fluorescent image by the fluorescence and an excitation light image by the excitation light transmitted through the endoscope filter ;
A color tone correction unit that corrects a color tone when the synthesized image is generated by the fluorescent image and the excitation light image in the synthesized image;
It is characterized by comprising.
With the above configuration, without adjusting the excitation light transmission filter on the light source device side, the color tone correction unit corrects the color tone when combining the fluorescence imaged image and the excitation light imaged image for display, and appropriately It enables fluorescence observation with hue contrast.

  According to the present invention, it is possible to generate a composite image that can be observed with an appropriate hue contrast from a fluorescent captured image and an excitation light captured image.

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

1 to 4 relate to a first embodiment of the present invention, FIG. 1 is a schematic block diagram of an overall configuration of an endoscope imaging system, FIG. 2 is a block diagram illustrating an internal configuration of a camera control unit, and FIG. 3 is a light source device. FIG. 4 shows a state in which the distal end side of the endoscope is inserted into the B balance cap.
First, the configuration of the present embodiment will be described. As shown in FIG. 1, an endoscope imaging system 1 according to a first embodiment of the present invention includes a light source device 2 that generates illumination light and an optical endoscope that is inserted into a body cavity to observe a subject image. 3, a camera head 4 that is detachably connected to the eyepiece 20 of the endoscope 3, and an image process for imaging an image signal from an image sensor in the camera head 4. It comprises a camera control unit (hereinafter referred to as CCU) 5 that outputs a video signal and a monitor 6 that displays the video signal output from the CCU 5.

The light source device 2 includes a lamp 10 such as a xenon lamp that emits light, a blue light filter 11a that is provided on the illumination optical path of the lamp 10, and that transmits blue excitation light as an excitation light transmission filter that transmits excitation light. A turret 12 having a normal light filter 11b that transmits light in a normal visible region, a condensing lens 13 that condenses light that has passed through the filter 11a or 11b, a motor 14 that rotates the turret 12, and a motor The motor control circuit 15 etc. which control rotation of 14 are provided.
The motor control circuit 15 is connected to an external foot switch 16 or the like, and the user operates the foot switch 16 to give an instruction to change the observation mode, so that the change instruction signal is sent to the motor control circuit 15. Entered. Upon receiving this signal, the motor control circuit 15 rotates the motor 14 to switch the filter arranged on the optical path.

When an instruction to switch to normal observation is given, the normal light filter 11b is arranged on the optical path to set the illumination state in the normal observation mode, and when an instruction to switch to fluorescence observation is given, on the optical path Is provided with a blue light filter 11a and is set to the illumination state in the fluorescence observation mode. Then, the light that has passed through the filter disposed on the optical path is collected and incident on the light guide of the endoscope 3.
The endoscope 3 includes an elongated insertion portion 18 to be inserted into a body cavity, an operation portion 19 provided at the rear end thereof, and an eyepiece portion 20 provided at the rear end of the operation portion 19.
Further, a light guide 21 for transmitting illumination light is inserted into the insertion portion 18, and this light guide 21 is inserted through a light guide cable 22 extending from the operation portion 19, and a light guide connector at the rear end thereof. 23 is detachably connected to the light source device 2. The illumination light from the light source device 2 is incident on the incident end face of the light guide connector 23.

The incident illumination light is transmitted to the tip surface of the light guide 21. The distal end surface of the light guide 21 is fixed inside the illumination window provided at the distal end portion 24 of the insertion portion 18, and the illumination light emitted from the distal end surface passes through the illumination lens 25 attached to the illumination window. Then, it is irradiated to the subject side such as an affected part in the body cavity.
An objective lens 26 is attached to an observation window provided adjacent to the illumination window. Return light (normal observation) from the subject is applied to the distal end surface of the image guide 27 arranged at the image forming position by the objective lens 26. In this case, a subject image is formed by reflected light (in the case of fluorescence observation, reflected light and fluorescence).
The optical image of the front end surface is transmitted to the rear end surface by the image guide 27. The rear end face is disposed in the vicinity of the eyepiece 20, and a cut filter 28 and an eyepiece lens 29 are disposed so as to face the rear end face and cut a part on the long wavelength side of blue light serving as excitation light. Yes. FIG. 3 shows transmission wavelength characteristics of the cut filter 28 and the blue light filter 11a that transmits the blue excitation light in the light source device 2.

In the camera head 4 that is detachably attached to the eyepiece 20, an imaging lens 31 for forming a subject image transmitted to the eyepiece 20 of the endoscope 3 on the imaging device is an eyepiece. 29 are arranged opposite to each other on 29 optical axes.
A dichroic mirror 32A and a dichroic mirror 32B that selectively reflect or transmit light in a specific wavelength region are sequentially arranged at an intermediate position on the optical axis that reaches the imaging position of the imaging lens 31.
The dichroic mirror 32A has a characteristic of reflecting light with a blue wavelength and transmitting other visible light components. The dichroic mirror 32B has a characteristic of reflecting the green light component in visible light and transmitting the remaining visible light component, in this case, red light.

Therefore, an optical image of the blue light component is formed at the imaging position on the side reflected by the dichroic mirror 32A, and the green imaging position is transmitted through the dichroic mirror 32A and reflected on the side reflected by the dichroic mirror 32B. An optical image is formed, and an optical image of red light is formed at the imaging position on the side transmitted through the two dichroic mirrors 32A and 32B.
A B_CCD 33 for imaging a blue light component is disposed at the imaging position on the side reflected by the dichroic mirror 32A.
A B band pass filter 36B that transmits a blue light component and restricts transmission of light other than the blue light component is disposed on the optical axis between the dichroic mirror 32A and the B_CCD 33.

In addition, a G_CCD 3B for imaging a green light component is disposed at the imaging position on the side that is transmitted through the dichroic mirror 32A and reflected by the dichroic mirror 32B. Further, on the optical axis between the dichroic mirror 32B and the G_CCD 33G, a G band pass filter 36G that transmits the green light component and restricts the transmission of light other than the green light component is disposed.
In addition, an R_CCD 33R for imaging a red light component is disposed at an imaging position on the side where the dichroic mirrors 32A and 32B are also transmitted. An R band pass filter 36R for restricting the above is disposed.

The optical images received by the B_CCD 33B, G_CCD 33G, and R_CCD 33R are converted into electrical signals, respectively, and become imaging signals. A signal line having one end connected to each of these B_CCD 33B, G_CCD 33G, and R_CCD 33R is inserted through a camera cable 37 extended from the camera head 4 and connected to a contact of a signal connector 38. The signal connector 38 is detachably connected to the CCU 5.
The CCU 5 is provided with an image processing unit 41 and a B balance switch 42, and an imaging signal transmitted from the camera head 4 is processed by the image processing unit 41 to generate a video signal, which is output to the monitor 6. An image and a fluorescent image are displayed.
FIG. 2 shows an internal configuration of the CCU 5 that performs image processing on an image pickup signal in this embodiment.

As shown in FIG. 2, the image processing unit 41 in the CCU 5 includes R, G, and B signal processing circuits 51a to 51c connected to the R, G, and B CCDs 33R, 33G, and 33B, and a B signal processing circuit. A color correction circuit (or luminance correction circuit) 52 connected to 51c, a video signal synthesis circuit (image signal synthesis circuit) 53 that synthesizes R, G, and B signals, a color correction circuit 52, and a video signal synthesis circuit 53; CPU 54 for controlling the above.
The R, G, B signal processing circuits 51a to 51c are inputted with image signals picked up by the CCDs 33R, 33G, 33B of G, R, B respectively, and correlated double sampling processing ( Only the signal components of each pixel are extracted by CDS processing) and the like, and color signals R, G, and B are generated. That is, the signal processing is performed on the imaging signals picked up by the CCDs 33R, 33G, and 33B for picking up the optical image transmitted to the eyepiece 20 of the endoscope 3 by dividing the optical image into the wavelength regions, and the component images in the respective wavelength regions are processed. Corresponding color signals R, G, B are generated.

  In this case, in the normal observation mode, the R, G, B signal processing circuits 51a to 51c generate the color signals R, G, B in this way, but in the fluorescence observation mode, the R, B signal processing circuits 51a, 51c. Will generate the fluorescence image and the excitation light image (blue image) described as the background illumination light 58 of FIG. 3 by the blue excitation light.

  The output signals of the R, G, B signal processing circuits 51a to 51c are synthesized by the video signal synthesis circuit 53 that performs color image synthesis for color display, and the luminance signal Y and the color signal C corresponding to the synthesized image. Is generated and output to the monitor 6.

Here, only the B signal processing circuit 51c is the color signal B in the color correction circuit 52 provided between the B signal processing circuit 51c and the video signal synthesis circuit 53 in accordance with control from the CPU 54 in the fluorescence observation mode. Is corrected. Then, the video signal synthesis circuit 53 corrects the contrast when performing color synthesis for color display of the fluorescence image by fluorescence and the excitation light image by excitation light, and performs color image synthesis with an appropriate hue contrast. To be
In the normal observation mode as described above, the R, G, and B signal processing circuits 51a to 51c perform signal processing on the output signals of the CCDs 33R, 33G, and 33B that capture the G, R, and B color components. And output R, G, and B color signals, respectively.

  In the fluorescence observation mode, the R signal processing circuit 51a picks up the image signal of the fluorescent image, and the B signal processing circuit 51c picks up the excitation light image picked up by the background illumination light 58 on the long wavelength side of the blue excitation light. Is output (abbreviated as BG in FIG. 2). When fluorescence is generated in the green wavelength region other than the red wavelength, the G signal processing circuit 51b also outputs a video signal of the fluorescence image.

When irradiating the color correction circuit 52 with blue light as excitation light for fluorescence observation, the hue contrast between the fluorescence image by fluorescence in the red wavelength region and the blue excitation light image is made appropriate. A blue setting value as setting information to be set is set to be input in advance (described later).
The CPU 54 is connected to the motor control circuit 15 of the light source device 2, and a detection signal indicating whether the current illumination light is the blue light filter 11 a or the normal light filter 11 b is input to the CPU 54. The color correction circuit 52 is controlled depending on whether the state is the normal light observation state (normal observation mode) or the fluorescence observation state (fluorescence observation mode).
FIG. 3 shows the transmission wavelength characteristics of the blue light filter 11 a of the light source device 2 and the cut filter 28 provided in the eyepiece 20 of the endoscope 3. When the blue excitation light passing through the blue light filter 11a is irradiated from the distal end of the endoscope 3, only the tumor part containing the fluorescent agent as a photosensitive substance is shown in the red wavelength region, specifically, as shown in FIG. For example, becomes fluorescence 56 having a peak intensity around 630 nm and is imaged by the R_CCD 33R.

However, since red fluorescence is smaller than blue light, a part of the blue light is cut by the cut filter 28. However, if all of the blue light is cut off, the fluorescent image is invisible except for the fluorescent portion that generates fluorescence. Therefore, the overlapping portion 57 in which the transmission characteristic portions of both filters are somewhat overlapped is provided to provide the illumination light 58 for the blue background. The illumination light 58 generates a blue excitation light image.
The illumination light 58 that generates the blue excitation light image has a weak red fluorescence and a poor hue contrast when the ratio of the transmission part is large, but when the ratio is small, the fluorescence (green to red light) of the living tissue due to the excitation light is now reduced. ) Side wins, the tissue becomes whitish and the hue contrast worsens.
Therefore, the blue background illumination light 58 is desirably an appropriate constant amount. However, since both the blue light filter 11a and the cut filter 28 vary within the wavelength tolerance, the light quantity of the background illumination light 58 is obtained by combining two filters. However, in this embodiment, the fluctuation is suppressed as follows by image processing in the CCU 5 as the image processing means.

  FIG. 4 shows a B balance cap 61 used when the B balance switch 42 of the CCU 5 is used. The B balance cap 61 has, for example, a cylindrical shape with a bottom, and on the inner side, a reflection wavelength characteristic that provides a reflected light intensity suitable for fluorescence observation when the biological tissue is irradiated with blue light in advance. The paint which is similar to is applied.

In this case, the color correction circuit 52 performs color correction so that the output signal of the B signal processing circuit 51c picked up in this case becomes a constant value. As a result, even when the light quantity of the illumination light 58 varies depending on the combination of the filters, it is not necessary to adjust the transmission characteristics by adjusting the angle with respect to the blue light filter 11a on the light source device 2 side. A color composite image that enables fluorescence observation with contrast can be generated.
Next, the operation of this embodiment will be described.

When the power is turned on in the state shown in FIG. 1, the motor control circuit 15 of the light source device 2 sets, for example, the normal light filter 11b as an initial state on the illumination optical path.
Then, a white subject is prepared by using a white balance cap (not shown), and the white balance switch is turned on. Then, the CPU 54 outputs the output signals of two signal processing circuits (here, G, B signal processing circuits 51b, 51c) in the R, G, B signal processing circuits 51a to 51c as outputs of the remaining R signal processing circuits 51a. The gain of the internal amplifier is set so that the luminance level of the signal matches.
That is, the white balance state is set so that a white subject is displayed in white. In this case, the color correction circuit 52 passes through the input signal, for example, and outputs the output signal (or sets the gain of the amplifier inside the color correction circuit 52 to 1).

In the present embodiment, since the cut filter 28 is disposed on the eyepiece 20 of the endoscope 3, the blue short wavelength side is cut off, and in the case of imaging, the incident of green and red Although the blue component is smaller than that of light, this white balance processing ensures the white balance state by setting the gain of the amplifier in the B signal processing circuit 51c larger than that of the other circuits. Normal observation.
After the white balance adjustment is completed, the foot switch 16 is operated so that the blue light filter 11a is arranged on the illumination optical path. In this case, blue light is irradiated from the distal end of the endoscope 3.
Here, as shown in FIG. 4, the distal end of the endoscope 3 is placed in the B balance cap 61 and the B balance switch 42 of the CCU 5 is pressed, and the observation state in the fluorescence observation mode is observed with appropriate hue contrast ( Display) to make adjustments.

As described above, when the distal end of the endoscope 3 is placed in the B balance cap 61 and the B balance switch 42 is pressed, the blue reflected light reflected by the inner surface of the B balance cap 61 is received by the B_CCD 33B, and the B signal The color signal B is generated by the processing circuit 51c.
At this time, under the control of the CPU 54, the color correction circuit 52 adjusts the shade of blue paint or the gain of the amplifier in the color correction circuit 52 so that the measured blue color signal B becomes an appropriate blue setting value. This is stored and saved in a storage means such as a memory in the color correction circuit 52 as a correction value (gain value).
Thereafter, when fluorescence observation is performed, the blue correction value is reflected by the color correction circuit 52 (the gain value of the amplifier is held), so that the illumination light is generated by combining the filters (generating an excitation light image). The variation in color tone caused by the difference in the amount of light 58 can be suppressed.

When the fluorescence observation is actually performed on the living tissue, the color signal corresponding to the fluorescence image from the R signal processing circuit 51 a and the signal corresponding to the excitation light image from the color correction circuit 52 are generated by the video signal synthesis circuit 53. Color identification is performed, and an identification display (for example, superimpose) of the color synthesized fluorescent image is superimposed on the color fluorescent image and output to the monitor 6 under the control of the CPU 54, and the surgeon has an appropriate hue contrast. The fluorescent image of the color can be observed.
Therefore, this embodiment has the following effects.
According to the configuration of the present embodiment described above, variations due to filter combinations can be suppressed by image processing, so that a fluorescent image having an appropriate hue contrast can always be obtained. This makes it easy to discriminate even a minute tumor, so that examination and tumor resection can be performed efficiently.

In general hospitals and the like, endoscopic examination is performed on a single light source device 2 using a plurality of endoscopes 3 and camera heads 4, so that such a case can be appropriately handled. That is, it is not necessary to adjust the transmission characteristics of the blue light filter 11a as the excitation light transmission filter on the light source device 2 side, and corresponds to the combination with the cut filter 28 of the endoscope 3 on the CCU 5 side as the image processing device. Color correction can be easily performed.
Furthermore, if the adjustment amount of the blue paint can be changed, it can be set to a color shade desired by the operator.
In the present embodiment, the camera head 4 mounted on the eyepiece 20 of the optical endoscope 3 is a three-plate image sensor that separates the three color components and captures optical images of the respective components. Although the employed camera head is employed, the present invention can be applied to the case of a camera head using a single-plate image sensor in which a color filter such as a mosaic filter is attached to the imaging surface.

When a single-plate image sensor is used, a color separation circuit is provided on the CCU 5 side, and the color signal is separated from the signal corresponding to the excitation light image as shown in FIG. Correction or luminance correction may be performed and combined with the fluorescent image signal.
Further, as a modification of the present embodiment, an electronic endoscope including an optical endoscope 3 and an imaging element such as a camera head 4 may be used. In this case, the cut filter 28 may be disposed in front of the imaging surface of the image sensor, and the image sensor may be of a type that captures an optical image transmitted by the image guide 27 or the image of the objective lens 26. The thing of the structure which has arrange | positioned the image pick-up element in the position may be sufficient.

Next, Embodiment 2 of the present invention will be described with reference to FIG. The configuration of the present embodiment is almost the same as that of the first embodiment, but adopts a configuration in which the transmission characteristics of the light source device 2 and the endoscope 3 are different.
In this embodiment, as shown in FIG. 5, the excitation light transmission filter 11a ′ of the light source device 2 is used as the blue excitation light transmission range, and the blue excitation light transmission range overlaps with the transmission range of the blue excitation light. A double bandpass filter having two transmission ranges, ie, a background illumination light 58 set on the longer wavelength side which is not necessary, is employed.
The background illumination light 58 is set within the transmission wavelength of the cut filter 28 ′ of the endoscope 3.

Here, the wavelength tolerance is set so that the transmission range for generating the illumination light 58 in the excitation light transmission filter 11a ′ falls within the transmission wavelength of the cut filter 28 ′ even if there is variation due to the filter 11a ′. .
Other configurations are the same as those of the first embodiment. Next, the operation of this embodiment will be described.
Although the basic operation is the same as that of the first embodiment, the variation of the illumination light 58 depends only on the excitation light transmission filter 11a ′ of the light source device 2 by using the filter configuration shown in FIG. , Variation is suppressed.
Further, since the variation of the illumination light 58 is only the excitation light transmission filter 11a ′ on the light source device 2 side, once the blue balance is corrected by operating the B balance switch 42, the correction is performed even if the endoscope 3 is changed. There is a merit that it is not necessary.

Therefore, this embodiment has the following effects.
If it is the above structure, once it performs blue correction by operating the B balance switch 42 with respect to the filter characteristic of the excitation light transmission filter 11a 'of the light source device 2, the correction for each change of the endoscope 3 can be performed. It becomes unnecessary.
Therefore, if the blue correction is performed in the shipping inspection of the light source device 2, the user does not need to perform the blue correction, and the time required for the endoscopic inspection and the operation using the endoscope 3 can be shortened.
Further, it is not necessary to attach the B balance cap 61 to each system 1.
In the above description, light in the blue wavelength region is used as the excitation light, and imaging is performed with fluorescence in the red wavelength region, and the background illumination light is blue. However, the background illumination light is, for example, from green to blue. Any wavelength region may be supported.

FIG. 6 shows a configuration of the image processing unit 41B of the CCU 5B in a modification corresponding to such a case. In this modification, the image processing unit 41 described in the first embodiment adjusts the luminance levels of both signals with respect to the output signals of the G signal processing circuit 51b and the B signal processing circuit 51c as shown in FIG. The luminance adjustment circuit 71 for changing the hue or tone from both signals and the tone adjustment circuit 72 for changing the hue or tone are input to the video signal synthesis circuit 53.
Further, instead of the B balance switch 42, a balance switch 42 'is employed. Further, in this case, a balance cap is used instead of the B balance cap 61, and by using this balance cap, the brightness adjustment circuit 71 is provided on the excitation light image side when color-combining the fluorescence image and the excitation light image. The signal strength can be set to an appropriate value.

Further, the CPU 54 is connected to the color tone adjustment operation unit 73. For example, when the user operates a variable resistor that constitutes the color tone adjustment operation unit 73, the CPU 54 causes the hue when the color adjustment circuit 72 combines G and B. Alternatively, the color tone is changed. Other configurations are the same as those of the second embodiment.
In this modification, in the fluorescence observation mode, a signal of the fluorescence image is input from the R signal processing circuit 51a to the video signal synthesis circuit 53. In this case, a signal corresponding to the excitation light image captured with the excitation light is the G signal processing circuit. The video signal synthesis circuit 53 is input from either or both of the 51b and the B signal processing circuit 51c.
The video signal synthesis circuit 53 color-synthesizes the fluorescence image signal and the excitation light image signal. The surgeon can perform fluorescence observation by operating the color tone adjustment operation unit 73 to set the hue or color tone preferred by the surgeon.
Note that the video signal synthesis circuit 53 is not limited to the one that outputs a video signal converted from a color signal into a luminance signal and a color difference signal. , G, B channels may be applied.

[Appendix]
1. Light source means for generating light in the visible wavelength region including excitation light;
An excitation light transmission filter provided in the light source means and transmitting the excitation light;
An inside provided with a filter that irradiates light from the light source means, transmits only a part of the excitation light in the reflected light from the subject, and transmits a fluorescence and a subject image through the filter; With a scope,
Image processing means for processing and imaging the image pickup signal from the image pickup means;
In an endoscope imaging system comprising:
A composite image generating means provided in the image processing means, for generating a composite image by the fluorescence image by the fluorescence and the excitation light image by the excitation light;
A color tone correction unit that corrects a color tone when the synthesized image is generated by the fluorescent image and the excitation light image in the synthesized image;
An endoscope imaging system comprising:

2. In Supplementary Note 1, the endoscope includes an optical endoscope that enables observation of an optical image, and a camera head that is attached to an eyepiece of the optical endoscope and includes the imaging element.
3. In Supplementary Note 1, the color tone correcting unit sets the luminance level or the gain of the amplifier in the excitation light image captured under a preset condition corresponding to the fluorescent image to a constant value.

  An excitation light transmission filter is disposed on the optical path of the light source device, the excitation light transmission filter is irradiated on the subject side, fluorescence imaging is performed using an imaging device, and the generated fluorescence image is obtained using a part of the excitation light. When the generated excitation light image is synthesized and displayed on the monitor, even if the filter characteristics of the excitation light transmission filter vary, the variation is corrected by image processing so that fluorescence observation can be performed with an appropriate color tone. Become.

  When making observations,

1 is a schematic block diagram of an overall configuration of an endoscope imaging system according to Embodiment 1 of the present invention. The block diagram which shows the internal structure of CCU. The spectral transmission characteristic figure of the filter provided in the filter provided in the light source device, and an endoscope. The figure which shows the state which inserted the front end side of the endoscope in B balance cap. The spectral transmission characteristic figure of the filter provided in the filter provided in the light source device in Example 2 of this invention, and an endoscope. The block diagram which shows the internal structure of CCU in a modification.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Endoscope imaging system 2 ... Light source device 3 ... Endoscope 4 ... Camera head 5 ... CCU
6 ... Monitor 10 ... Lamp 11a ... Blue light filter 11b ... Normal light filter 20 ... Eyepiece part 26 ... Objective lens 28 ... Cut filter 32A, 32B ... Dichroic mirror 33R, 33G, 33B ... CCD
DESCRIPTION OF SYMBOLS 41 ... Image processing part 42 ... B balance switch 51a-51c ... Signal processing circuit 52 ... Color correction circuit 53 ... Video signal synthesis circuit 61 ... B balance cap

Claims (4)

Light source means for generating light in the visible wavelength region including excitation light;
An excitation light transmission filter provided in the light source means and transmitting the excitation light;
An endoscope that irradiates light from the light source means and obtains an optical subject image by reflected light from the subject;
An endoscope filter that is provided in the endoscope and transmits only a part of the excitation light and transmits fluorescence;
An imaging means attached to the eyepiece of the endoscope for imaging a subject image;
Image processing means for processing and imaging the image pickup signal from the image pickup means;
In an endoscope imaging system comprising:
A combined image generating unit that is provided in the image processing unit and generates a combined image by a fluorescent image by the fluorescence and an excitation light image by the excitation light transmitted through the endoscope filter ;
A color tone correction unit that corrects a color tone when the synthesized image is generated by the fluorescent image and the excitation light image in the synthesized image;
An endoscope imaging system comprising:   The excitation light transmission filter is a blue filter that transmits blue excitation light, and the endoscope filter is a filter characteristic that transmits fluorescence in a red wavelength region in which a photosensitive substance is generated by the blue excitation light. The endoscope imaging system according to claim 1, further comprising:   The color tone correction unit corrects the luminance level of the blue image as the excitation light image obtained by imaging under the blue excitation light and corrects the color tone of the composite image generated by the composite image generation unit. The endoscope imaging system according to claim 1, wherein:   The excitation light transmission filter is a double band having a transmission wavelength of blue excitation light and background illumination light set in a transmission wavelength region that does not overlap with the blue excitation light and is transmitted by the endoscope filter. The endoscope imaging system according to claim 1, wherein the endoscope imaging system is a pass filter.

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