JP5970054B2 - Endoscope system, light source device for endoscope system, and method for operating endoscope system - Google Patents

Description

  The present invention relates to an endoscope system that acquires an observation image in a subject using a plurality of semiconductor light sources such as RGB LEDs, a light source device for the endoscope system, and a method for operating the endoscope system.

  In the field of medical endoscopes in recent years, by irradiating a subject with narrowband light of a specific wavelength, the surface blood vessels and surface microstructures that were difficult to observe with broadband light such as white light are clarified. Narrow-band light observation is possible. The shape and pattern of the superficial blood vessels and superficial microstructures are important clues for identifying lesions such as cancer and estimating the depth of the lesions. Can be improved.

  For example, in narrowband light observation shown in Patent Document 1, blue narrowband light having a center wavelength of 415 nm and green narrowband light having a center wavelength of 540 nm are alternately irradiated on the subject, and narrowband light of each color is irradiated. Imaging is performed every time. A blue narrowband image obtained by imaging blue narrowband light is assigned to the B channel and G channel of the monitor, while a green narrowband image obtained by imaging green narrowband light is assigned to the R channel of the monitor. As a result, a pseudo-color narrowband light image in which both the surface blood vessel having the absorption characteristic for the blue narrowband light and the middle deep blood vessel having the absorption characteristic for the green narrowband light are emphasized is displayed on the monitor.

  However, since the wavelength band of narrowband light used in narrowband light observation is limited, the amount of light is inevitably insufficient. This shortage of light becomes noticeable in a distant view where the distance between the endoscope illumination unit and the observation area is large. Therefore, in the endoscope of Patent Document 2, in order to be able to make a diagnosis reliably even in observation in a distant view state, in addition to the narrow band light image, the monitor includes white light having a wide wavelength band. A normal light image obtained by imaging is displayed in parallel.

Japanese Patent No. 3586157 JP 2004-321244 A

  However, when the normal light image and the narrowband light image are displayed in parallel on the monitor as in Patent Document 2, it is necessary to compare these two types of images, which imposes a burden on the surgeon performing the diagnosis. It becomes. Therefore, under conditions where the surface blood vessels and the surface microstructure that greatly contribute to the diagnosis of the lesion are clarified and the light quantity is insufficient such as in a distant state so that the surgeon can make a diagnosis with only one image. There is also a need for an endoscope system that can acquire an image with sufficient brightness.

  The present invention provides an endoscope system, a light source device for an endoscope system, and a method for operating the endoscope system that can acquire an image in which an observation site such as a superficial blood vessel and a superficial fine structure is clarified. For the purpose.

  An endoscope system according to the present invention includes a blue semiconductor light source that emits blue band B light, a green semiconductor light source that emits green band G light, a red semiconductor light source that emits red band R light, and B light and G light. Image acquisition means for acquiring a normal light image and a special light image with different brightness by imaging the inside of the subject irradiated with the R light, and B light irradiated when acquiring the normal light image, Switching between the first light amount value of G light and R light and the second light amount value of B light, G light, and R light that is different from the first light amount value and is emitted when acquiring a special light image A light amount control unit that performs control on each semiconductor light source, and the light amount control unit obtains a special light image that clarifies the surface blood vessels and the surface fine structure, and outputs the first light of B light, G light, and R light. Two light quantity values are set such that B light quantity> G light quantity> R light quantity. When acquiring a special light image with a clear structure, the second light quantity value of B light, G light, and R light should be set so that the G light quantity or R light quantity is greater than the B light quantity. It is characterized by.

The image acquisition means is obtained by imaging using a color imaging device when the second light quantity value of B light, G light, and R light has a relationship of light quantity of B light> light quantity of G light> light quantity of R light. Of the blue image signal, green image signal, and red image signal, the blue image signal is preferably assigned to the B image and the G image of the special light image, and the green image signal is preferably assigned to the R image of the special light image.

When the second light quantity value of the B light, the G light, and the R light has a relationship of the light quantity of the B light> the light quantity of the G light> the light quantity of the R light, the image acquisition means includes a band pass filter that transmits the high frequency band. It is preferable to extract the fine blood vessels in the mucosal surface layer by removing the blood vessels in the deep mucosa layer by applying to the special light image.

When the second light quantity value of B light, G light, and R light is related to the light quantity of G light or the light quantity of R light larger than the light quantity of B light, a blue image obtained by imaging using a color image sensor Of the signal, the green image signal, and the red image signal, the green image signal is preferably assigned to the B image and the G image of the special light image, and the red image signal is preferably assigned to the R image of the special light image.

The image acquisition means transmits the low frequency band when the second light quantity value of the B light, the G light, and the R light is set so that the G light quantity or the R light quantity is greater than the B light quantity. By applying a filter to the special light image, it is preferable to remove superficial fine blood vessels and extract blood vessels in the middle mucosa.

It is preferable that the image acquisition unit emphasizes the blood vessel to be observed while applying a combination of a low-pass filter, a band-pass filter, and a high-pass filter to the special light image, while suppressing other blood vessels.

  It is preferable to include an image processing unit that performs predetermined processing on the special light image, and an image combining unit that combines the special light image that has been subjected to the predetermined processing and the normal light image to generate a combined image. The predetermined process is preferably a process for extracting a predetermined color component. The predetermined process is preferably a process for extracting a portion having a predetermined contrast. The predetermined process is preferably a process for extracting a portion having a predetermined structure. It is preferable that the image processing unit further performs a process of extracting dense blood vessels on the special light image that has been subjected to the predetermined process.

  In order to acquire a normal light image and a special light image having different brightness, the present invention images the inside of a subject by irradiating blue band B light, green band G light, and red band R light. In a light source device of an endoscope system that supplies illumination light for illuminating the inside of a subject to an endoscope apparatus, a blue semiconductor light source that emits B light, a green semiconductor light source that emits G light, and R light are emitted. When acquiring a special light image with a red semiconductor light source, a first light amount value of B light, G light, and R light irradiated when acquiring a normal light image, and a light amount value different from the first light amount value A light amount control unit that performs switching control with respect to the second light amount values of the irradiated B light, G light, and R light to each semiconductor light source, and the light amount control unit clarifies the surface blood vessels and the surface layer microstructure. When acquiring a special light image, use the second light quantity value of B light, G light, and R light as the light quantity of B light. When acquiring a special light image with the structure of the middle-layer blood vessels and middle-layers clarified with the relationship of> light amount of G light> light amount of R light, the second light amount value of B light, G light, and R light is set to G light. The amount of light or the amount of R light is larger than the amount of B light.

  The present invention includes a step in which a blue semiconductor light source emits blue band B light, a green semiconductor light source emits green band G light, a red semiconductor light source emits red band R light, and an image acquisition means includes B light, In an operating method of an endoscope system, the method comprising: obtaining a normal light image and a special light image having different brightness by imaging the inside of a subject irradiated with G light and R light. However, the B light, the G light, and the R light that are irradiated when acquiring the normal light image, and the B light that is irradiated when acquiring the special light image having a light amount value different from the first light amount value. This is a step of performing switching control with respect to the second light amount values of light, G light, and R light for each semiconductor light source, and the light amount control means acquires a special light image that clarifies the surface blood vessels and the surface layer microstructure. Sometimes the second light quantity value of B light, G light, and R light is When acquiring a special light image with the structure of the middle-layer blood vessels and middle-layers clarified with the relationship of> light amount of G light> light amount of R light, the second light amount value of B light, G light, and R light is set to G light. And a step of making the amount of light of R or the amount of light of R light larger than the amount of light of B light.

  According to the present invention, the special light image obtained under the condition of the light amount of B light> the light amount of G light> the light amount of R light is an image in which the surface blood vessels and the surface microstructure are clarified. A special light image acquired in a state where the light amount of G light or the light amount of R light is larger than the light amount of B light is an image in which the mid-deep blood vessels and the medium tissues of the mid-deep layer are clarified rather than the surface blood vessels. Yes.

It is a figure which shows the external appearance of an endoscope system. It is a figure which shows the internal structure of an endoscope system. It is a figure for demonstrating the light quantity adjustable range of B-LED, G-LED, and R-LED. It is a figure for demonstrating the light quantity value of B light, G light, and R light set at the time of normal light observation mode. It is a figure for demonstrating the light quantity value of B light, G light, and R light set at the time of special light observation mode. It is a graph showing the spectral transmittance of the color filter of each color in a color image sensor. It is a figure for demonstrating operation | movement of the image pick-up element at the time of normal light observation mode. It is a figure for demonstrating operation | movement of the image pick-up element at the time of special light observation mode. It is a figure for demonstrating the production | generation method of a synthesized image. It is a figure for demonstrating the effect | action of this invention. It is a figure which shows B-LED, G-LED, and R-LED arrange | positioned at the front-end | tip part of a scope.

  As shown in FIGS. 1 and 2, an endoscope system 10 irradiates a light source device 11 that generates illumination light for illuminating a subject, illumination light from the light source device 11 to an observation region of the subject, and reflects the reflected light. An endoscope apparatus 12 that captures light or the like, a processor apparatus 13 that performs image processing on an image signal obtained by the endoscope apparatus 12, and a display apparatus 14 that displays an endoscopic image or the like obtained by image processing; And an input device 15 composed of a keyboard or the like.

  The endoscope system 10 includes a normal light observation mode in which a normal light image including a subject image of visible light having a wavelength range from blue to red is displayed on the display device 14, a blood vessel to be observed on the normal light image, A special light observation mode for displaying on the display device 14 a composite image obtained by combining special light images with a clarified structure is provided. In the normal light observation mode, a period for acquiring a normal light image for one frame (normal light image acquisition frame) is set in advance. In the special light observation mode, similarly to the normal light observation mode, a period for acquiring a normal light image for one frame (normal light image acquisition frame) is set in advance. The acquisition period (special light image acquisition frame) is also set in advance. These observation modes are appropriately switched based on an instruction input from the changeover switch 17 or the input device 15 of the endoscope apparatus.

  The light source device 11 includes three LEDs (Light Emitting Diodes) B-LED, G-LED, and R-LED, a B light amount control unit 20b, a G light amount control unit 20g, and an R light amount control unit 20r. As shown in FIG. 3, the B-LED emits B light with a blue wavelength band, the G-LED emits G light with a green wavelength band, and the R-LED emits R light with a red wavelength band. To emit. These B light, G light, and R light can be increased or decreased within a certain range. B light, G light, and R light emitted from each LED are incident on optical fibers 24b, 24g, and 24r through condenser lenses (not shown), respectively.

  A laser light source may be used instead of the LED. As the laser light source, for example, a broad area type InGaN laser diode can be used, and an InGaNAs laser diode, a GaNAs laser diode, or the like is preferably used.

  The B light amount control unit 20b, the G light amount control unit 20g, and the R light amount control unit 20r control the B-LED light amount, the G-LED light amount, and the R-LED light amount, respectively. The control of the amount of light for each LED differs depending on the set observation mode. When the normal light observation mode is set, as shown in FIG. 4, the light amounts of B light, G light, and R light are substantially equal to each other (light amount L of B light Lb = light amount L of G light Lg). = R light amount Lr), B-LED, G-LED, R-LED are controlled.

  When the special light observation mode is set, as shown in FIG. 5, in the normal light image acquisition frame, the light amounts of B light, G light, and R light are substantially equal to each other (Lb = Lg = Lr), B-LED, G-LED, R-LED are controlled. On the other hand, in the special light image acquisition frame, the B-LED, the G-LED, and the R-LED are controlled so that the B light amount Lb> the G light amount Lg> the R light amount Lr. In the special light observation mode, the normal light image acquisition frame and the special light image acquisition frame are alternately switched, so that the light amount of each LED is also switched as described above in accordance with the switching of the frame.

  Switching between the normal light image acquisition frame and the special light image acquisition frame in the special light observation mode is performed in a very short time from the viewpoint of securing good moving image properties. Therefore, a light source that adjusts the amount of light in conjunction with this frame switching needs to have a responsiveness equal to or higher than the frame switching speed. In terms of this responsiveness, the LED which is a semiconductor light source sufficiently satisfies the requirement.

  As shown in FIGS. 1 and 2, the combiner 21 combines the B light, G light, and R light from the optical fibers 24b, 24g, and 24r. By combining these three colors of B light, G light, and R light, broadband light having a wavelength range from blue to green is generated. The broadband light emitted from the combiner 21 is demultiplexed into two systems of light by a coupler 22 which is a demultiplexer. The two separated broadband light beams are transmitted by the light guides 28 and 29. The light guides 28 and 29 are composed of bundle fibers obtained by bundling a large number of optical fibers. In addition, it is good also as a structure which puts the light from each LED directly into the light guides 28 and 29, without using the combiner 21 and the coupler 22. FIG.

  The endoscope apparatus 12 includes an electronic endoscope, and includes an endoscope scope 32, an illumination unit 33 that emits two systems (two lights) of light transmitted by light guides 28 and 29, and an observation area. An imaging section 34 for imaging, an operation section 35 for performing an operation for bending and observing the distal end portion of the endoscope scope 32, and the endoscope scope 32, the light source device 11, and the processor device 13 are detachable. The connector part 36 connected to is provided.

  The endoscope scope 32 is provided with a flexible portion 38, a bending portion 39, and a scope distal end portion 40 in this order from the operation portion 35 side. Since the flexible portion 38 has flexibility, it can be bent in the subject when the endoscope is inserted. The bending portion 39 is configured to be freely bent by a turning operation of an angle knob 35 a disposed in the operation portion 35. Since the bending portion 39 can be bent in an arbitrary direction and an arbitrary angle according to the region of the subject, the scope distal end portion 40 can be directed to a desired observation region.

  The scope tip 40 is provided with an illumination unit 33 and an imaging unit 34. The imaging unit 34 includes a single observation window 42 that captures reflected light from the subject region at a substantially central position of the scope distal end 40. The illumination unit 33 includes two illumination windows 43 and 44 provided on both sides of the imaging unit 34, and each illumination window 43 and 44 radiates broadband light toward the observation region.

  An optical system such as an objective lens unit (not shown) for capturing the image light of the observation region of the subject is provided in the back of the observation window 42, and further in the back of the objective lens unit An imaging device 60 such as a CCD (Charge Coupled Device) or a CMOS (Complementary Metal-Oxide Semiconductor) that receives the image light of the region and images the observation region is provided.

  The imaging element 60 receives light from the objective lens unit on a light receiving surface (imaging surface), photoelectrically converts the received light, and outputs an imaging signal (analog signal). The image sensor 60 is a color CCD, and on its light receiving surface, a set of a B pixel having a spectral transmittance 63, a G pixel having a spectral transmittance 64, and an R pixel having a spectral transmittance 65 shown in FIG. A large number of pixel groups are arranged in a matrix.

  An imaging signal (analog signal) output from the imaging device 60 is input to the A / D converter 68 through the scope cable 67. The A / D converter 68 converts the imaging signal (analog signal) into an image signal (digital signal) corresponding to the voltage level. The converted image signal is input to the processor device 13 via the connector unit 36.

  The imaging control unit 70 performs imaging control of the image sensor 60. As shown in FIG. 7, in the normal light observation mode, the broadband light BB having the relationship B light amount Lb = G light amount Lg = R light amount Lr is photoelectrically converted within the normal light image acquisition frame period. A total of two steps: a step of accumulating the electric charge obtained in this step and a step of reading out the electric charge accumulated in the B pixel as a B1 image signal, the electric charge accumulated in the G pixel as a G1 image signal, and the electric charge accumulated in the R pixel as an R1 image signal Steps are performed. This is repeated while the normal light observation mode is set.

  On the other hand, in the special light observation mode, as shown in FIG. 8, the same accumulation and reading steps as those in the normal light observation mode are performed within the normal light image acquisition frame period. Then, within the special light image acquisition frame period, electric charges obtained by photoelectric conversion of the broadband light BB having the relationship of the light quantity Lb of B light> the light quantity Lg of G light> the light quantity Lr of R light are accumulated. A total of two steps are performed: a step and a step of reading the charge accumulated in the B pixel as the B2 image signal, the charge accumulated in the G pixel as the G2 image signal, and the charge accumulated in the R pixel as the R2 image signal. These two frames of image pickup control are repeatedly performed while the special light observation mode is set.

  Although not shown, a forceps channel for inserting a tissue collection treatment tool or the like, an air supply / water supply channel, or the like inside the operation unit 35 and the endoscope scope 32 in the endoscope apparatus 12. Various channels are provided.

  As illustrated in FIG. 2, the processor device 13 includes a control unit 72, an observation image generation unit 73, and a storage unit 74, and the display device 14 and the input device 15 are connected to the control unit 72. . The control unit 72 is based on an instruction such as an observation mode input from the changeover switch 17 of the endoscope device 12 or the input device 15, and the B, G, R light amount control unit 20b of the observation image generation unit 73 and the light source device 11. , 20g, 20r, the imaging control unit 70 of the endoscope apparatus 12 and the operation of the display device 14 are controlled.

  The observation image generation unit 73 includes a normal light image generation unit 80, a special light image generation unit 81, and a composite image generation unit 82. The normal light image generation unit 80 generates a normal light image based on the B1, G1, R1 image signals acquired in the normal light image acquisition frame. The image processing unit 80a in the normal light image generation unit 80 performs color conversion processing such as 3 × 3 matrix processing, gradation conversion processing, and three-dimensional LUT processing on the B1, G1, and R1 image signals. Color enhancement processing that enhances the color difference between blood vessels and mucous membranes, and image structure enhancement processing such as sharpness processing and contour enhancement are performed. The normal light image subjected to these processes is displayed on the display device 14 as it is in the normal light observation mode, while being transmitted to the composite image generation unit in the special light observation mode.

  The special light image generation unit 81 includes a signal correction unit 81a and an image processing unit 81b, and generates a special light image based on the B2 and G2 image signals acquired in the special light image acquisition frame. Since the B2 and G2 image signals are generated based on the B light and the G light having the relationship of the light quantity Lb of the B light> the light quantity Lg of the G light, in the special light image generated from these image signals, The surface blood vessels and the superficial fine blood vessels are more clarified than the middle-deep blood vessels and the like.

  The signal correction unit 81a generates a corrected G2 image signal by correcting the G2 image signal using the R2 image signal, and corrects the corrected B2 image signal by correcting the B2 image signal using the G2 image signal. Generate. The reason for correcting the G2 image signal and the B2 image signal in this way is as follows. Due to the characteristics of the color filter, not only the G light but also the R light is incident on the G pixel of the CCD. Similarly, not only B light but also G light is incident on the B pixel due to the characteristics of the color filter. Therefore, if a special light image is generated using the B2 image signal and the G2 image signal as they are, the B image is affected by the G image component, and the G image is an image affected by the R image component. . Therefore, as described above, it is necessary to correct the B2 image signal and the G2 image signal.

  The R2 image signal used for the correction processing of the G2 image signal and the G2 image signal used for the correction processing of the B2 image signal are both R pixels and G pixels which are sub-pixels constituting one pixel together with the pixels to be corrected. The image signal may be used. Alternatively, a pixel adjacent to the pixel on which correction processing is performed may be selected as appropriate, and the image signal of that pixel may be used.

The G2 image signal correction process is performed according to the following equation.
Correction G2 image signal = G2 image signal−α × R2 image signal Here, α is a coefficient determined based on the characteristics of the color filter of the G pixel.

Further, the B2 image signal correction process is performed by the following equation.
Correction B2 image signal = B2 image signal−β × correction G2 image signal Alternatively, correction processing may be performed using the following equation.
Correction B2 image signal = B2 image signal−β × (G2 image signal−α × R2 image signal)
Here, β is a coefficient determined based on the characteristics of the color filter of the B pixel.

  The image processing unit 81b generates a special light image based on the corrected B2 image signal and the corrected G2 image signal. The corrected B2 image signal is assigned to the B image and the G image of the special light image, and the corrected G2 image signal is assigned to the R image of the special light image. Thereafter, the image processing unit performs processes similar to the various processes in the image processing unit on the special light image. When assigning image signals, image correction such as multiplying an image by a predetermined coefficient may be performed as necessary.

  The composite image generation unit 82 performs a predetermined process on the special light image generated by the special light image generation unit 81 to generate a composite image, and the normal light image generation unit 80 on the generated composite image. Is combined with the normal light image generated in (1) to generate a composite image. The composite image generation unit 82 includes a composite image generation unit 82a and an image synthesis unit 82b.

  The composition image generation unit 82a performs frequency processing on the special light image using a low pass filter (LPF), a band pass filter (BPF), a high pass filter (HPF), and the like. A special light image is obtained by extracting the fine blood vessels on the surface of the mucosa (that is, removing the blood vessels in the deep mucosa and the like) by frequency filtering the special light image with the HPF or a BPF that transmits a predetermined high frequency band. It is done. The special light image after the frequency filtering is referred to as “composition image”. A special image is processed with LPB or a BPF that transmits a predetermined frequency band of low frequency, thereby extracting a thick blood vessel in the middle mucosa from the special light image (that is, removing superficial fine blood vessels). Is obtained.

  The frequency band for frequency filtering is preferably set as appropriate in accordance with the observation site, the target image, and the like. That is, the combination of LFP, BPF, and HPF can enhance the blood vessels to be observed while suppressing other blood vessels.

  Further, the process of extracting or removing the target part from the special light image is not limited to the frequency process. For example, the mucous membrane in the vicinity of the surface layer is bluish by B light, while the mucosa in the middle and deep layers takes advantage of the property of being greenish by G light, and the surface blood vessels can be extracted by removing the blue component from the special light image. Moreover, the middle-layer blood vessel can be extracted by removing the green component from the special light image.

  In addition, by taking advantage of the property that the contrast is higher in the area where the superficial microvessels and middle-deep blood vessels are present, the part (pixels) having a contrast of a predetermined value or more is extracted, and the superficial microvessels are extracted. An image for synthesis from which blood vessels and middle-deep blood vessels are extracted is obtained. Note that the contrast threshold value at the time of extraction can be appropriately set according to the observation site, endoscope characteristics, past diagnosis results, simulation, and the like.

  In addition, a lesion such as a cancer takes advantage of the characteristic that the fine blood vessels on the surface layer have a special blood vessel pattern, and the special blood vessel pattern is extracted by pattern matching, so that a composite image from which the cancer is extracted can be obtained. . A known method can be used for pattern matching. In addition, the types of special blood vessel patterns may be those described in known literature, or those sampled from an image of a typical lesion.

  Note that only one of the frequency processing, color component extraction, contrast extraction, and blood vessel pattern extraction described above may be performed, or a combination thereof may be performed.

  Furthermore, after performing the above-described frequency processing, color component extraction, contrast extraction, and blood vessel pattern extraction, in the image obtained by these processing, a dense portion such as a fine blood vessel on the surface layer satisfies a predetermined condition. A further extracted region (for example, a region where the density of blood vessels is high or a region where the blood vessel density is equal to or higher than a certain value) may be used as a synthesis image. It should be noted that the density of blood vessels and the like is preferably detected by a known method such as spatial frequency measurement or MTF (Modulation Transfer Function) measurement. Further, the threshold value for the degree of congestion can be appropriately set according to the observation site, the characteristics of the endoscope, the past diagnosis result, the simulation, and the like.

  As shown in FIG. 9, the image composition unit 82b combines the normal light image 90 generated by the normal light image generation unit 80 and the composition image 91 generated by the composition image generation unit 82a. A composite image 92 is generated. Therefore, the composite image 92 is sufficiently bright even under a situation where the amount of light is insufficient, such as in a distant view, and the parts to be observed such as surface blood vessels and surface fine structures are clarified. The generated composite image is displayed on the display device 14.

  Next, the operation of the present invention will be described with reference to the flowchart of FIG. First, the special light observation mode is set by the changeover switch 17 of the endoscope apparatus. Thereby, from B-LED, G-LED, and R-LED, the light quantity value is set to Lb = Lg = Lr, and the light quantity value is set to Lb> Lg> Lr. The subject is irradiated with B light, G light, and R light alternately. When the B light, G light, and R light with the light amount value Lb = Lg = Lr are irradiated (normal light image acquisition frame), the return light is picked up by the image pickup device 60 and the B1 image signal, G1 An image signal and an R1 image signal are output. On the other hand, when the B light, G light, and R light whose light quantity values are Lb> Lg> Lr are irradiated (special light image acquisition frame), the return light is picked up by the image pickup device 60 and the B2 image signal, G2 An image signal and an R2 image signal are output.

  A normal light image is generated based on the B1 image signal, the G1 image signal, and the R1 image signal output from the image sensor 60 during the normal light image acquisition frame. On the other hand, a special light image is generated based on the B2 image signal and the G2 image signal output from the image sensor 60 during the special light image acquisition frame. When generating the special light image, the special light image is generated from the corrected B2 image signal obtained by correcting the B2 image signal with the R2 image signal and the corrected G2 image signal obtained by correcting the G2 image signal with the R2 image signal.

  Next, frequency processing such as frequency filtering and bandpass filter is performed on the special light image. At that time, the special light image is frequency-processed with HPF or a BPF that transmits a predetermined high frequency band, thereby extracting microvessels and fine structures on the surface layer of the mucosa and removing blood vessels and the like in the middle mucosa. Thereby, a special light image in which the fine blood vessels and the fine structure of the surface layer are clarified is obtained. This special light image is used as a composition image to be combined with the normal light image.

  Then, a composite image is generated by combining the composite image and the normal light image. The generated composite image is displayed on the display device 14. The composite image is sufficiently bright even in situations where the amount of light is insufficient, and the superficial microvessels that contribute to the diagnosis of the lesion are clarified, so the surgeon must perform the diagnosis reliably. Can do. When the special light observation mode setting is canceled, the composite image display is stopped.

  In the above embodiment, the B-LED, G-LED, and R-LED are installed in the light source device, but may be provided in the scope distal end portion 40 of the endoscope device 12 as shown in FIG. The B-LED, G-LED, and R-LED provided at the scope distal end 40 are connected to the B light amount control unit 20b in the light source device via the LED communication cables 100b, 100g, and 100r in the endoscope device 12. The G light amount control unit 20g and the R light amount control unit 20r are controlled. By providing the B-LED, G-LED, and R-LED at the scope distal end 40 in this way, it is possible to irradiate the subject directly without attenuating the B light, G light, and R light. Light utilization efficiency can be increased.

  Further, in the above-described embodiment, the relationship between the light amount values of the light irradiated during the special light image acquisition frame is set such that the light amount Lb of the B light> the light amount Lg of the G light> the light amount Lr of the R light, thereby clarifying the surface blood vessels. In place of or in addition to this, the structure of the middle-deep blood vessel and the middle-deep layer is clarified by making the light quantity Lg of G light or the light quantity Lr of R light larger than the light quantity of B light. Also good. In this case, the special light image is generated based on the G2 image signal and the R2 image signal. For example, the G2 image signal is preferably assigned to the B image and the G image of the special light image, and the R2 image signal is preferably assigned to the R2 image of the special light image.

DESCRIPTION OF SYMBOLS 10 Endoscope system 11 Light source device 20b B light quantity control part 20g G light quantity control part 20r R light quantity control part 80 Normal light image generation part 81 Special light image generation part 81a Signal correction part 82 Composite image generation part 82b Image composition part

Claims (11)

A blue semiconductor light source emitting blue band B light;
A green semiconductor light source emitting G light in the green band;
A red semiconductor light source that emits red light in the red band;
Image acquisition means for acquiring a normal light image and a special light image having different brightness by imaging the inside of the subject irradiated with B light, G light, and R light;
B light, B light, G light, and R light emitted when obtaining the normal light image, and B light emitted when obtaining the special light image having a light quantity value different from the first light quantity value. A light amount control means for performing switching control with respect to the second light amount value of light, G light, and R light for each semiconductor light source
The light amount control means includes
When acquiring a special light image that clarifies the surface blood vessels and the surface microstructure, the second light quantity value of the B light, G light, and R light is expressed as follows: B light quantity> G light quantity> R light quantity West,
When acquiring a special light image that clarifies the structure of the middle blood vessel or the middle deep layer, the second light quantity value of the B light, the G light, and the R light is obtained from the light quantity of the G light or the light quantity of the R light from the light quantity of the B light. Endoscope system characterized by a large relationship. The image acquisition means includes
When the second light quantity value of the B light, G light, and R light has a relationship of B light quantity> G light quantity> R light quantity, a blue image signal obtained by imaging using a color imaging device The endoscope according to claim 1, wherein, among the green image signal and the red image signal, the blue image signal is allocated to the B image and the G image of the special light image, and the green image signal is allocated to the R image of the special light image. system. When the second light quantity value of the B light, G light, and R light is set to have a relationship in which the light quantity of G light or the light quantity of R light is larger than the light quantity of B light, the blue color obtained by imaging using a color imaging device image signal, a green image signal, out of the red image signal, said green image signal B image and the G image of the special light image, according to claim 1, wherein allocating the red image signal in the R image of the special light image Endoscope system. The image acquisition means includes
The endoscope system according to claim 1, wherein a special blood image is subjected to a combination of a low-pass filter, a band-pass filter, and a high-pass filter to enhance a blood vessel to be observed while suppressing other blood vessels. An image processing unit for performing predetermined processing on the special light image;
The endoscope system according to claim 1, further comprising an image composition unit configured to compose the special light image subjected to the predetermined processing and the normal light image to generate a composite image. 6. The endoscope system according to claim 5, wherein the predetermined process is a process of extracting a predetermined color component. The endoscope system according to claim 5, wherein the predetermined process is a process of extracting a portion having a predetermined contrast. The endoscope system according to claim 5, wherein the predetermined process is a process of extracting a portion having a predetermined structure. Wherein the image processing unit, with respect to the predetermined processing has been subjected special light image, further, of the claims 5 to 8 any one of claims, characterized in that performing the process of extracting the dense portion of the vessel Endoscopic system. An endoscope apparatus that images a subject by irradiating blue-band B light, green-band G light, and red-band R light to acquire a normal light image and a special light image having different brightnesses. In contrast, in a light source device of an endoscope system that supplies illumination light for illuminating the inside of a subject,
A blue semiconductor light source emitting the B light;
A green semiconductor light source emitting the G light;
A red semiconductor light source emitting the R light;
B light, B light, G light, and R light emitted when obtaining the normal light image, and B light emitted when obtaining the special light image having a light quantity value different from the first light quantity value. A light amount control means for performing switching control with respect to the second light amount value of light, G light, and R light for each semiconductor light source,
The light amount control means includes
When acquiring a special light image that clarifies the surface blood vessels and the surface microstructure, the second light quantity value of the B light, G light, and R light is expressed as follows: B light quantity> G light quantity> R light quantity West,
When acquiring a special light image that clarifies the structure of the middle blood vessel or the middle deep layer, the second light quantity value of the B light, the G light, and the R light is obtained from the light quantity of the G light or the light quantity of the R light from the light quantity of the B light. A light source device for an endoscope system characterized by having a large relationship. A blue semiconductor light source emitting blue band B light, a green semiconductor light source emitting green band G light, a red semiconductor light source emitting red band R light, and an image acquisition means comprising the B light and the G light In the operation method of the endoscope system, the method includes: acquiring a normal light image and a special light image having different brightness by imaging the inside of the subject irradiated with the R light.
The light quantity control means obtains the special light image having a first light quantity value of B light, G light, and R light irradiated when obtaining the normal light image, and a light quantity value different from the first light quantity value. Is a step in which each semiconductor light source is controlled to switch to the second light quantity value of the B light, G light, and R light to be irradiated, and the light quantity control means specially clarifies the superficial blood vessels and superficial fine structures. When acquiring a light image, the second light quantity value of the B light, G light, and R light is set such that the light quantity of the B light> the light quantity of the G light> the light quantity of the R light, and the structure of the middle layer blood vessel and the middle depth layer is clear When acquiring a special light image, the second light amount value of the B light, G light, and R light has a step in which the light amount of G light or the light amount of R light is greater than the light amount of B light. An operation method of an endoscope system characterized by the above.

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