JP6874087B2 - Endoscope system and how to operate the endoscope system - Google Patents

Description

The present invention relates to an endoscope system that forms an illumination light to irradiate an observation object using a plurality of light sources, and a method of operating the endoscope system.

In the medical field, diagnosis using an endoscopic system including an endoscopic light source device, an endoscope, and a processor device is widely performed. The endoscopic light source device is a device that generates light (hereinafter referred to as illumination light) that irradiates an observation target such as a mucous membrane of a body cavity. Conventionally, a light source that emits light having a wide band continuous spectrum such as a xenon lamp (hereinafter referred to as continuous spectrum light) has been used as an endoscope light source device, but in recent years, it has replaced a wide band light source such as a xenon lamp. In addition, semiconductor light sources such as LEDs (Light Emitting Diodes) are being used. When a semiconductor light source is used as the light source, for example, by using a combination of a plurality of semiconductor light sources that emit light of different colors such as a blue LED, a green LED, and a red LED, the spectrum obtained by superimposing these lights is used. Light having a spectrum (hereinafter referred to as multicolor spectrum light) becomes illumination light.

For example, in the endoscope system of Patent Document 1, four independently controllable semiconductor light sources are mounted on an endoscope light source device, and the spectral spectrum of illumination light (light amount for each wavelength) is controlled by controlling the amount of light emitted from each. By adjusting the distribution), it is possible to irradiate the observation target with illumination light having the optimum characteristics according to the image characteristics to be acquired. Specifically, in order to obtain an image having a large dynamic range with respect to brightness, an image having a low color temperature, an image having a high color temperature, and an image when a special narrow band wavelength is applied to a narrow area, the illumination light is used. The spectral spectrum and the like are adjusted.

Further, the endoscope system of Patent Document 2 is equipped with a plurality of independently controllable semiconductor light sources, identifies the model of the endoscope, and sets the driving conditions of each semiconductor light source according to the model of the endoscope. It is set. Specifically, since the light transmission characteristics of the light guide for propagating the illumination light differ depending on the model, the model of the endoscope is identified and the light amount ratio of each semiconductor light source according to the light transmission characteristics of the light guide is determined. It is set.

Japanese Unexamined Patent Publication No. 2013-255655 Japanese Unexamined Patent Publication No. 2013-20216

As described above, the illumination light used in the endoscopic system is changing from the conventional continuous spectrum light by a xenon lamp or the like to the multicolor spectrum light by a plurality of semiconductor light sources. Then, since the spectral spectra are different from each other, even if the image of the observation target imaged by irradiating the continuous spectrum light and the image of the observation target imaged by irradiating the multicolor spectrum light are the same observation target. It may look different. The difference in the appearance of the observation target between the case where continuous spectrum light is used as illumination light and the case where multicolor spectrum light is used as illumination light cannot be said to be superior, but multiple semiconductor light sources are independent. Since it is controllable and the spectral spectrum can be adjusted according to the observation target or the like, there is an advantage that the observation can be performed more flexibly when the multicolor spectrum light is used as the illumination light.

On the other hand, in endoscopic systems, continuous spectrum light from a xenon lamp or the like has been used as illumination light for a long period of time, so many doctors are accustomed to how the observation target looks when irradiated with continuous spectrum light from a xenon lamp or the like. ing. For this reason, it is desired that even when multicolor spectrum light from a plurality of semiconductor light sources is used as illumination light, it can be observed in the same manner as when continuous spectrum light from a conventional xenon lamp or the like is used as illumination light. .. In addition, since many of the endoscopic images accumulated as past cases are also taken by continuous spectrum light by a xenon lamp or the like, even when multicolor spectrum light by a plurality of semiconductor light sources is used as illumination light, the past In order to make it easier to simply compare with this case, it is desired to be able to obtain an endoscopic image similar to the case where continuous spectrum light is used as illumination light.

In order to meet the above demand, it is sufficient that the spectral spectrum of the continuous spectrum light can be reproduced by a plurality of semiconductor light sources, but in reality, the spectral spectrum of the continuous spectrum light cannot be completely reproduced by the plurality of semiconductor light sources. For example, when a blue LED or a green LED whose light amount becomes smaller as the wavelength is farther from the center wavelength is used as a light source, the light amount of these intermediate colors (wavelength near the middle of blue and green) adjusts the light amount of the blue LED and the green LED. It is difficult to change by just doing this, and when the center wavelengths of the blue LED and the green LED are brought close to the light intensity of the continuous spectrum light, the light intensity of the intermediate colors of blue and green is significantly lower than the light intensity of the continuous spectrum light. On the contrary, if the amount of light of the blue LED and the green LED is increased in order to bring the amount of light of the intermediate colors of blue and green closer to the continuous spectrum light, the color near the center wavelength of the blue LED and the color of the center wavelength of the green LED are the continuous spectrum light. The amount of light is greatly exceeded.

In the present invention, continuous spectrum light is used as illumination light even when a plurality of light sources that independently emit light of different colors are used and multicolor spectrum light obtained by superimposing these lights is used as illumination light. It is an object of the present invention to provide an endoscopic system and a method of operating the endoscopic system so that an observation target can be observed in almost the same manner as in the case.

The endoscopic system of the present invention is a purple light source that emits V light, which is purple light in the first wavelength band, a blue light source that emits B light, which is blue light in the second wavelength band, and green light in the third wavelength band. A first multicolor spectrum having a plurality of light sources having a green light source that emits G light and a red light source that emits R light that is red light in the fourth wavelength band, and superimposing the light emitted by the plurality of light sources. An imaging sensor having a light source unit that emits first multicolor spectrum light and pixels of a plurality of colors having sensitivity to different colors, a Cy pixel having sensitivity to cyan, an Mg pixel having sensitivity to magenta, and yellow. The amount of light for each color obtained by controlling a plurality of light sources, an imaging sensor having a Ye pixel having a sensitivity to the same wavelength and a G pixel having a sensitivity to green, and receiving the first multicolor spectrum light with the pixels of the plurality of colors. A light source control unit that matches the ratio of integrated values with the ratio of integrated light quantities for each color obtained by receiving continuous spectrum light, which is white light emitted by a xenon lamp, halogen lamp, or white LED, with pixels of multiple colors. When the image pickup sensor is regarded as an S pixel having a color filter having a total sensitivity of Sum, which is the sum of the sensitivities of Cy pixel, Mg pixel, Ye pixel, and G pixel for each wavelength, the light source control unit V. Light quantity integrated value obtained by integrating the spectral spectrum of light for each wavelength of the total sensitivity Sum of S pixels in the range of the first wavelength band, the second wavelength band, the third wavelength band, and the fourth wavelength band, respectively. Is VS1, VS2, VS3, VS4, and the spectral spectrum of B light is the product of the total sensitivity Sum of the S pixels for each wavelength in the range of the first wavelength band, the second wavelength band, the third wavelength band, and the fourth wavelength band. The integrated values of the amount of light obtained by integrating in are BS1, BS2, BS3, and BS4, and the spectral spectrum of G light is the product of the total sensitivity Sum of the S pixels for each wavelength in the first wavelength band, the second wavelength band, and the above. The light amount integrated values obtained by integrating in the third wavelength band and the fourth wavelength band are defined as GS1, GS2, GS3, and GS4, and the spectral spectrum of R light is set for each wavelength of the total sensitivity Sum of S pixels. The light quantity integrated values obtained by integrating the products in the first wavelength band, the second wavelength band, the third wavelength band, and the fourth wavelength band are RS1, RS2, RS3, and RS4, and the spectroscopy of continuous spectrum light is defined. By integrating the spectrum for each wavelength of the total sensitivity Sum of the S pixels in the range of the first wavelength band, the second wavelength band, the third wavelength band, and the fourth wavelength band, respectively. When the obtained integrated light intensity values are XS1, XS2, XS3, and XS4, the light intensity ratios of V light, B light, G light, and R light Cv: Cb: Cg: Cr so as to satisfy the following formula (5). Is calculated .

Observation target type light amount ratio for each Cv: Cb: Cg: equipped with a light amount ratio storage unit for storing the Cr, the light source control section, the light quantity ratio Cv of each type to be observed: Cb: Cg: light quantity ratio among the Cr It is preferable to select Cv: Cb: Cg: Cr. A light amount detection unit that detects the amount of light emitted by a plurality of light sources is provided, and the light source control unit uses the detection result of the light amount detection unit to specify a specified value of the amount of light that forms the first multicolor spectrum light among the plurality of light sources. On the other hand, it is preferable to set the light amount of the remaining light source according to the light amount of the most deteriorated light source having the largest shortage of light amount. It is preferable that the light amount detection unit repeatedly detects the light emitted by the plurality of light sources while the plurality of light sources are emitting light.

The ratio of the integrated light intensity for each color obtained by receiving the first multicolor spectral light with the pixels of multiple colors is the ratio of the integrated light intensity for each color obtained by receiving the continuous spectral light with the pixels of multiple colors. It is preferable to have a verification unit for verifying whether or not they match. It is equipped with a light amount detection unit that detects the amount of light emitted by a plurality of light sources, and the verification unit uses the detection result of the light amount detection unit to receive the first multicolor spectral light with the pixels of a plurality of colors for each color. It is preferable to verify whether or not the ratio of the integrated light amount matches the ratio of the integrated light amount for each color obtained by receiving the continuous spectrum light by the pixels of a plurality of colors. The verification unit uses the output of the imaging sensor to receive the first multicolor spectrum light with the pixels of multiple colors, and the ratio of the integrated light amount for each color obtained by receiving the light of the first multicolor spectrum with the pixels of the multiple colors. It is preferable to verify whether or not it matches the ratio of the integrated light amount for each color obtained. It is preferable that the light source control unit controls a plurality of light sources by using the verification result by the verification unit.

According to the present invention, a purple light source that emits V light, which is purple light in the first wavelength band, a blue light source that emits B light, which is blue light in the second wavelength band, and green that emits G light, which is green light in the third wavelength band. A first multicolor having a light source and a plurality of light sources having a red light source that emits R light which is red light in the fourth wavelength band, and having a first multicolor spectrum obtained by superimposing the light emitted by the plurality of light sources. An image sensor that has a light source unit that emits spectral light and pixels of multiple colors that are sensitive to different colors, such as Cy pixels that are sensitive to cyan, Mg pixels that are sensitive to magenta, and Ye that is sensitive to yellow. In the method of operating an endoscopic system including an image sensor having pixels and G pixels having sensitivity to green, a light source control unit controls a plurality of light sources and emits a first multicolor spectrum light of a plurality of colors. The ratio of the integrated light amount for each color obtained by receiving light from each pixel is calculated for each color obtained by receiving continuous spectrum light, which is white light emitted by a xenon lamp, a halogen lamp, or a white LED, with multiple color pixels. In the step of matching the ratio of the integrated light amount, the light source control unit has a color filter having a total sensitivity Sum of the imaging sensor, which is the sum of the sensitivities of Cy pixel, Mg pixel, Ye pixel, and G pixel for each wavelength. When regarded as S pixels, the spectral spectrum of V light is the product of the total sensitivity Sum of S pixels for each wavelength in the range of the first wavelength band, the second wavelength band, the third wavelength band, and the fourth wavelength band, respectively. The integrated light amount obtained by integration is VS1, VS2, VS3, VS4, and the spectral spectrum of B light is the product of the total sensitivity Sum of the S pixels for each wavelength, which is the first wavelength band, the second wavelength band, and the third wavelength. The integrated value of the amount of light obtained by integrating in the band and the range of the fourth wavelength band is BS1, BS2, BS3, and BS4, and the spectral spectrum of G light is the product of the total sensitivity Sum of the S pixels for each wavelength. The integrated light amount obtained by integrating in the wavelength band, the second wavelength band, the third wavelength band, and the fourth wavelength band is defined as GS1, GS2, GS3, and GS4, and the spectral spectrum of R light is defined as that of the S pixel. The integrated light amount obtained by integrating the product of the total sensitivity Sum for each wavelength in the first wavelength band, the second wavelength band, the third wavelength band, and the fourth wavelength band, respectively, is RS1, RS2, RS3, RS4. Let the spectral spectrum of continuous spectrum light be the product of each wavelength of the total sensitivity Sum of S pixels in the range of the first wavelength band, the second wavelength band, the third wavelength band, and the fourth wavelength band. When the light intensity integrated values obtained by integrating in the circle are XS1, XS2, XS3, and XS4, the light intensity ratios of V light, B light, G light, and R light so as to satisfy the following equation (5). It has a step of calculating Cv: Cb: Cg: Cr.

The method of operating the endoscopic system and the endoscopic system of the present invention is to obtain a multicolor spectrum light obtained by superimposing light emitted by a plurality of light sources with a plurality of color pixels, and to obtain an integrated value of the amount of light for each color. Multicolor spectral light by matching the ratio with the ratio of the integrated light amount for each color obtained by receiving continuous spectral light having at least a part of the wavelength band of the light emitted by the white light source by the pixels of a plurality of colors. Is used as the illumination light, the observation target can be observed in almost the same manner as when the continuous spectrum light is used as the illumination light.

It is an external view of an endoscope system. It is a block diagram which shows the function of an endoscope system. It is a graph which shows the spectral spectrum of the multicolor spectrum light. It is a graph which shows the spectral spectrum of the continuous spectrum light emitted by a xenon lamp. It is a graph which shows the spectral spectrum of a color filter. It is a graph which shows the spectral spectrum of the continuous spectrum light which V light, B light, G light, R light and a xenon lamp emit. It is a graph which shows the balance of V light and B light of the 1st multicolor spectrum light. It is a graph which shows the reflectance of the esophagus. It is a graph which shows the return light of V light, B light, G light, and R light. It is a graph which shows the return light of the continuous spectrum light of a xenon lamp. It is a graph which shows the 1st multicolor spectrum light which considered the reflectance of the esophagus. It is a graph which shows the reflectance of the esophagus, the stomach, and the large intestine. It is a block diagram of an endoscope system which changes the light amount ratio of each color light which forms the 1st multicolor spectrum light according to the type of an observation object. It is a graph which shows the spectral spectrum of a complementary color filter. It is a graph which shows the total sensitivity of a complementary color filter. It is a graph which shows the 1st multicolor spectrum light for a complementary color system color image sensor. It is a graph which shows the spectral spectrum of the 2nd multicolor spectrum light. It is a block diagram of the endoscope system which switches between the 1st multicolor spectrum light and the 2nd multicolor spectrum light depending on the model of an endoscope. It is a block diagram of the endoscope system which switches between the 1st multicolor spectrum light and the 2nd multicolor spectrum light depending on the model of an endoscope. It is a graph which shows the time-dependent deterioration of a semiconductor light source. It is a block diagram of the endoscope system which emits the 1st multicolor spectrum light corresponding to the time-dependent deterioration of a semiconductor light source. It is a graph which shows the spectral spectrum of the 1st multicolor spectrum light when the semiconductor light source deteriorates with time. It is a graph which shows the spectral spectrum of the 1st multicolor spectrum light which adjusted the amount of light according to the light source which deteriorated most with time. It is a block diagram of the endoscope system which has a verification part. It is a block diagram of the endoscope system which has a verification part. It is a block diagram of an endoscope system provided with a band limiting part. It is a schematic diagram of a capsule endoscope.

[First Embodiment]
As shown in FIG. 1, the endoscope system 10 includes an endoscope 12, an endoscope light source device 14, a processor device 16, a monitor 18, and a console 19. The endoscope 12 is optically connected to the endoscope light source device 14 and electrically connected to the processor device 16. The endoscope 12 includes an insertion portion 12a to be inserted into the subject, an operation portion 12b provided at the base end portion of the insertion portion 12a, and a curved portion 12c and a tip portion provided on the tip end side of the insertion portion 12a. It has 12d. By operating the angle knob 12e of the operating portion 12b, the curved portion 12c bends. By this bending operation, the tip portion 12d is directed in a desired direction. Further, the operation unit 12b is provided with a zoom operation unit 13 and the like in addition to the angle knob 12e.

The processor device 16 is electrically connected to the monitor 18 and the console 19. The monitor 18 outputs and displays an image of each observation mode, image information attached to the image, and the like. The console 19 functions as a user interface that accepts input operations such as function settings. An external recording unit (not shown) for recording an image, image information, or the like may be connected to the processor device 16.

As shown in FIG. 2, the endoscope light source device 14 is a device that generates illumination light to irradiate an observation target, and controls a light source unit 20 having a plurality of light sources and each light source of the light source unit 20. A unit 22 and an optical path coupling unit 23 that couples the optical paths of light emitted by the light source unit 20 are provided.

The light source unit 20 includes a purple LED (hereinafter referred to as V-LED (Violet Light Emitting Diode)) 20a, a blue LED (hereinafter referred to as B-LED (Blue Light Emitting Diode)) 20b, and a green LED (hereinafter referred to as G-LED). It has a four-color LED (referred to as Green Light Emitting Diode) 20c and a red LED (hereinafter referred to as R-LED (Red Light Emitting Diode)) 20d.

As shown in FIG. 3, the V-LED 20a is a purple light source that emits purple light (hereinafter referred to as V light) having a center wavelength of 405 nm and a wavelength band of 380 to 420 nm. The B-LED 20b is a blue light source that emits blue light having a central wavelength of 450 nm and a wavelength band of 420 to 490 nm (hereinafter referred to as B light). The G-LED 20c is a green light source that emits green light having a center wavelength of 524 nm to 525 nm and a wavelength band of 480 nm to 590 nm (hereinafter referred to as G light). The R-LED 20d is a red light source that emits red light (hereinafter referred to as R light) having a center wavelength of 628 to 629 nm and a wavelength band of 580 to 700 nm. The center wavelength of each of these LEDs 20a to 20d has a range of about ± 5 nm to ± 10 nm.

The light source unit 20 emits multicolor spectrum light having a multicolor spectrum in which V light, B light, G light, and R light are superposed by a plurality of light sources that independently emit light of different colors. .. The wavelength band of V-LED20a and the wavelength band of B-LED20b overlap, the wavelength band of B-LED20b and the wavelength band of G-LED20c also overlap, and the wavelength band of G-LED20c and R-LED20d. There is also overlap in the wavelength band of. Further, since the amount of light emitted from each of the LEDs 20a to 20d (hereinafter, simply referred to as the amount of light) can be controlled independently, the spectral spectrum of the multicolor spectrum light can be changed by changing the amount of light of each of the LEDs 20a to 20d. .. In the present embodiment, the light source unit 20 is specified to mimic the case of observing using the wideband continuous spectrum light 26 of the white light emitted by the xenon lamp used in the conventional endoscopic system shown in FIG. 4 as the illumination light. V light, B light, G light, and R light are emitted with the balance of. The multicolor spectral light emitted by the light source unit 20 in this xenon emulated mode is hereinafter referred to as the first multicolor spectral light. The multicolor spectrum light having the spectral spectrum shown in FIG. 3 is the first multicolor spectrum light 25 of the present embodiment, and the spectral spectrum of the first multicolor spectrum light 25 is the first multicolor spectrum.

The light source control unit 22 individually controls the drive current, drive voltage, drive current or drive voltage of the LEDs 20a to 20d of the light source unit 20 when pulse-inputting them to the LEDs 20a to 20d, such as pulse width and pulse length. Controls the light emission timing and the amount of light emitted by each of the LEDs 20a to 20d. In the present embodiment, when the light source unit 20 emits the first multicolor spectrum light 25, the light source control unit 22 lights the LEDs 20a to 20d at the same time and the ratio of the light emission amounts of the LEDs 20a to 20d (hereinafter, hereinafter, Controls the light intensity ratio). Then, the light source control unit 22 controls the light amount ratio of each of the LEDs 20a to 20d to receive the first multicolor spectral light 25 by the pixels of the plurality of colors of the image sensor 48, respectively, to obtain the integrated value of the light amount for each color. The ratio is matched with the ratio of the integrated light amount for each color obtained by receiving the continuous spectrum light 26 with the pixels of a plurality of colors.

The light quantity integrated value is the amount of signal charge obtained by photoelectric conversion of each pixel of a plurality of colors by the image sensor 48. Therefore, depending on the model and settings of the image sensor 48, the signal charge is read out by applying different gains to each pixel of a plurality of colors and the image signal is output. It does not depend on the value of the gain applied at the time of reading. Further, the light intensity integrated value does not depend on the content of signal processing performed on the image signal by the processor device 16. In the present embodiment, the light intensity integrated value is the product of the spectral spectrum of the first multicolor spectral light (or the continuous spectral light 26 of the xenon lamp) emitted by the light source unit 20 and the spectral spectrum of the color filter of the image sensor 48 for each wavelength. Is calculated by integrating for each wavelength band of the color filter.

The continuous spectrum is a spectral spectrum of light having at least a part of the wavelength band of the light emitted by the white light source, and the continuous spectrum light is light having a continuous spectrum. The white light source is a light source that emits light having a gentle distribution over a visible light region (for example, 400 nm to 700 nm) from one light source. More specifically, the white light source is a xenon lamp, a halogen lamp, a white LED, or the like. Further, the light having at least a part of the wavelength band of the light emitted by the white light source means the light extracted from the light emitted by the white light source by a color filter or the like.

The multicolor spectrum is one spectral spectrum obtained by superimposing the spectral spectra of the light emitted by the plurality of light sources, and the light obtained by superimposing the light emitted by the plurality of light sources is the multicolor spectrum light. The wide band means that the wavelength band is wider than the wavelength band of the light emitted by at least one of the plurality of light sources (LEDs 20a to 20d) used in the light source unit 20. The white light of the xenon lamp is the wavelength band of V light emitted by LED 20a (purple wavelength band), the wavelength band of B light emitted by LED 20b (blue wavelength band), and the wavelength band of G light emitted by LED 20c (green wavelength band). ), And the wavelength band is wider than each wavelength band of the wavelength band (red wavelength band) of the R light emitted by the LED 20d, and includes components of each wavelength of all these wavelength bands (wavelength 350 nm or more and less than 700 nm), and , Light having a gentle distribution over the visible light region. Therefore, the white light emitted by the xenon lamp is the broadband continuous spectrum light 26.

The multicolor spectrum light (first multicolor spectrum light 25) emitted by the light source unit 20 is incident on the light guide 41 inserted into the insertion unit 12a via the optical path coupling unit 23. The light guide 41 is built in the endoscope 12 and the universal cord (the cord connecting the endoscope 12, the endoscope light source device 14 and the processor device 16), and is guided from the optical path coupling portion 23. The illumination light propagates to the tip portion 12d of the endoscope 12. A multimode fiber can be used as the light guide 41. As an example, a fine fiber cable having a core diameter of 105 μm, a clad diameter of 125 μm, and a diameter of φ0.3 to 0.5 mm including a protective layer serving as an outer skin can be used.

An illumination optical system 30a and an imaging optical system 30b are provided at the tip end portion 12d of the endoscope 12. The illumination optical system 30a has an illumination lens 45, and the illumination light propagated by the light guide 41 is irradiated to the observation target through the illumination lens 45. The image pickup optical system 30b includes an objective lens 46, a zoom lens 47, and an image pickup sensor 48. The return light from the observation target (light including fluorescence generated from the observation target or the like in addition to the reflected light) is incident on the image pickup sensor 48 via the objective lens 46 and the zoom lens 47. As a result, the observation target is imaged on the image sensor 48. The zoom lens 47 is freely moved between the telephoto end and the wide-angle end by operating the zoom operation unit 13, and the observation target to be imaged on the image sensor 48 is enlarged or reduced.

The image sensor 48 has pixels of a plurality of colors having sensitivity to different colors. That is, the image sensor 48 has pixels having different colors (spectral spectra of color filters) from each other. More specifically, the image pickup sensor 48 is a primary color system color image sensor having a primary color system color filter including blue, green, and red, and images the return light from the observation target with pixels of a plurality of colors, respectively, for each color. Outputs the image signal of. As the image sensor 48, a CCD (Charge Coupled Device) image sensor or a CMOS (Complementary Metal-Oxide Semiconductor) image sensor can be used. In the present embodiment, the image sensor 48 includes a blue color filter (hereinafter referred to as B filter), a green color filter (hereinafter referred to as G filter), and a red color filter (hereinafter referred to as R filter) having the spectral spectrum shown in FIG. ) Is provided for each pixel with any of the three color filters.

The B pixel (blue pixel) provided with the B filter receives the blue light component transmitted through the B filter in the return light from the observation target, and the G pixel (green pixel) provided with the G filter is the observation target. Of the return light from the light source, the green light component transmitted through the G filter is received. Similarly, the R pixel (red pixel) provided with the R filter receives the red light component transmitted through the R color filter among the return light from the observation target. Therefore, when the light source unit 20 emits the first multicolor spectrum light 25, the B pixel receives each return light of the V light and the B light among the first multicolor spectrum light 25, and the B image signal (blue image). Signal) is output. Similarly, when the light source unit 20 emits the first multicolor spectrum light 25, the G pixel receives the return light of the G light and outputs the G image signal (green image signal), and the R pixel is the R light. It receives the return light of and outputs the R image signal (red image signal).

The image signals of each color output by the image sensor 48 are transmitted to the CDS / AGC circuit 50. The CDS / AGC circuit 50 performs correlated double sampling (CDS) and automatic gain control (AGC) on an image signal which is an analog signal. The image signal that has passed through the CDS / AGC circuit 50 is converted into a digital image signal by the A / D converter 51. The digital image signal after A / D conversion is input to the processor device 16.

The processor device 16 includes a receiving unit 53, a DSP (Digital Signal Processor) 56, a noise removing unit 58, an image generation unit 62, and a video signal generation unit 66.

The receiving unit 53 receives a digital RGB image signal from the endoscope 12. The DSP 56 performs various signal processing such as defect correction processing, offset processing, gain correction processing, linear matrix processing, gamma conversion processing, and demosaic processing on the received image signal. In the defect correction process, the signal of the defective pixel of the image sensor 48 is corrected. In the offset processing, the dark current component is removed from the RGB image signal subjected to the defect correction processing, and an accurate zero level is set. In the gain correction process, the signal level is adjusted by multiplying the RGB image signal after the offset process by a specific gain. The RGB image signal after the gain correction processing is subjected to linear matrix processing for improving color reproducibility. After that, the brightness and saturation are adjusted by the gamma conversion process. The RGB image signal after the linear matrix processing is subjected to demosaic processing (also referred to as isotropic processing and simultaneous processing), and a signal of a color lacking in each pixel is generated by interpolation. By this demosaic processing, all the pixels have RGB signals of each color.

The noise removing unit 58 removes noise from the RGB image signal by performing noise removing processing (for example, by a moving average method, a median filter method, etc.) on the RGB image signal that has been demosaked by DSP 56. The noise-removed RGB image signal is transmitted to the image generation unit 62.

The image generation unit 62 performs color conversion processing, color enhancement processing, and structure enhancement processing on the RGB image signal to generate an image (hereinafter, referred to as an endoscopic image). In the color conversion process, the RGB image signal is subjected to color conversion processing by 3 × 3 matrix processing, gradation conversion processing, three-dimensional LUT (look-up table) processing, or the like. The color enhancement process is performed on the RGB image signal that has undergone the color conversion process. The structure enhancement process is a process for emphasizing the structure of an observation target such as a surface blood vessel or a pit pattern, and is performed on an RGB image signal after the color enhancement process. As described above, the endoscopic image is a color image using an RGB image signal that has undergone various image processing up to structure enhancement processing. The video signal generation unit 66 converts the endoscopic image generated by the image generation unit 62 into a video signal for display as an image that can be displayed on the monitor 18. Using this video signal, the monitor 18 displays an endoscopic image.

Hereinafter, the characteristics of the first multicolor spectral light 25 used by the endoscope system 10 of the present embodiment as the illumination light in the xenon emulated mode, and the V light, B light, and G light forming the first multicolor spectral light 25. How to obtain the light amount ratio of light and R light will be described.

First, the light source control unit 22 can arbitrarily change the light amount ratios of V light, B light, G light, and R light, but only adjusting the light amount ratio of each of these color lights is shown in FIG. As described above, the spectral spectrum of the continuous spectrum light 26 of the xenon lamp cannot be reproduced. For example, even if the light amounts of V light and B light are matched with the continuous spectrum light 26, the light amount in the intermediate wavelength band (wavelength band of about 420 nm to 430 nm) does not reach the light amount of the continuous spectrum light 26. On the contrary, when the light amount in the wavelength band between the V light and the B light is matched with the light amount of the continuous spectrum light 26, the light amount at the center wavelength of the V light and the B light greatly exceeds the light amount of the continuous spectrum light 26.

Therefore, instead of reproducing the continuous spectrum light 26 of the xenon lamp with the LEDs 20a to 20d of each color, the light source control unit 22 receives the first multicolor spectrum light 25 with the B pixel and the light intensity integrated value obtained with the G pixel. The ratio of the light intensity integrated value obtained by receiving light and the light intensity integrated value obtained by receiving light from the R pixel is the light intensity integrated value obtained by receiving the continuous spectrum light 26 of the xenon lamp with B pixel and the light intensity integrated value obtained by receiving light with G pixel. The light amount ratios of V light, B light, G light, and R light are adjusted so as to substantially match the ratio of the value and the light amount integrated value obtained by receiving light from the R pixel. By doing so, even if the spectral spectra of the first multicolor spectral light 25 and the continuous spectral light 26 of the xenon lamp are different, as a result, the image signals obtained by imaging the observation target with the imaging sensor 48 become equal, so that the monitor The endoscopic image displayed on 18 is substantially the same. That is, even if the spectral spectra are not matched, an endoscopic image can be obtained in which the observation target looks the same as when the xenon lamp is used.

Let Vb, Vg, and Vr be the integrated values of the amount of light obtained by receiving the V light forming the first multicolor spectrum light 25 with the B pixel, the G pixel, and the R pixel, respectively. Similarly, the integrated values of the amount of light obtained by receiving the B light forming the first multicolor spectral light 25 with the B pixel, the G pixel, and the R pixel are Bb, Bg, and Br, respectively, and the first multicolor spectral light 25 is set. Let Gb, Gg, and Gr be the integrated values of the amount of light obtained by receiving the G light that forms the first multicolor spectrum light 25 with the B pixel, the G pixel, and the R pixel, respectively, and let the R light that forms the first multicolor spectral light 25 be the B pixel and G. Let Rb, Rg, and Rr be the integrated values of the amount of light received by the pixels and the R pixels, respectively.

The light intensity integrated value Vb obtained by receiving V light with B pixels is, for example, the spectral spectrum of V light (see FIG. 6) in which the maximum value (light intensity of the center wavelength) is standardized to "1" and the spectral spectrum of the B color filter. It is obtained by integrating the product of each wavelength (see FIG. 5). Since the spectral spectrum of V light and the spectral spectrum of the B color filter are known, the light amount integrated value Vb obtained by receiving V light with the B pixel is a known quantity. The same applies to the other light intensity integrated values Vg, Vr, Bb, Bg, Br, Rb, Rg, and Rr.

Further, the integrated light quantity obtained by receiving the continuous spectrum light 26 of the xenon lamp with the B pixel is Xb, the integrated light quantity obtained by receiving the continuous spectrum light 26 of the xenon lamp with the G pixel is Xg, and the xenon lamp is Let Xr be the integrated value of the amount of light obtained by receiving the continuous spectrum light 26 of the above with the R pixel. The light intensity integrated value Xb obtained by receiving the continuous spectrum light 26 with the B pixel is, for example, the spectrum of the continuous spectrum light 26 (see FIG. 4 or FIG. 6) of a xenon lamp whose maximum value is standardized to “1” and the spectrum of the B color filter. It is obtained by integrating the product of each wavelength of the spectrum (see FIG. 5). Since the spectral spectrum of the continuous spectrum light 26 and the spectral spectrum of the B color filter are known, the light quantity integrated value Xb obtained by receiving the continuous spectrum light 26 with the B pixel is a known quantity. The same applies to the other light intensity integral values Xg and Xr.

Then, the light amount ratio of V light, B light, G light, and R light forming the first multicolor spectrum light 25 is set to V light: B light: G light: R light = Cv: Cb: Cg: Cr. The values of Cv, Cb, Cg, and Cr are variables, and the integrated value of the amount of light obtained by receiving the first multicolor spectrum light 25 with the B pixel, the integrated value of the amount of light obtained by receiving the light with the G pixel, and the value received with the R pixel The ratio of the light amount integral value obtained by the above is the light amount integral value obtained by receiving the continuous spectrum light 26 of the xenon lamp with the B pixel, the light amount integral value obtained by receiving the light with the G pixel, and the light amount integral obtained by receiving the light with the R pixel. Determine to match the ratio of values.

That is, the light amount ratios Cv: Cb: Cg: Cr of V light, B light, G light, and R light forming the first multicolor spectrum light 25 may be determined so as to satisfy the formula (1). Since the number of variables is larger than the number of equations, the light amount ratios of V light, B light, G light, and R light cannot be uniquely determined as Cv: Cb: Cg: Cr.

そこで、本実施形態ではまずＢ画素で受光するＶ光とＢ光の光量比（Ｖ光：Ｂ光＝Ｋｖ：Ｋｂ）を決定する。具体的には、Ｂ画素で受光する波長帯域を、Ｖ光の第１波長帯域（波長３８０ｎｍ以上４３０ｎｍ未満）とＢ光の第２波長帯域（波長４３０ｎｍ以上４８０ｎｍ未満）の２つの波長帯域に区切る。そして、第１多色スペクトル光２５の第１波長帯域の光量積分値と、キセノンランプの連続スペクトル光２６の第１波長帯域の光量積分値が一致し、かつ、第１多色スペクトル光２５の第２波長帯域の光量積分値と、キセノンランプの連続スペクトル光２６の第２波長帯域の光量積分値を一致するように、Ｖ光とＢ光の光量比Ｋｖ：Ｋｂを決定する。

Therefore, in the present embodiment, first, the light amount ratio of the V light and the B light received by the B pixel (V light: B light = Kv: Kb) is determined. Specifically, the wavelength band received by the B pixel is divided into two wavelength bands, the first wavelength band of V light (wavelength 380 nm or more and less than 430 nm) and the second wavelength band of B light (wavelength 430 nm or more and less than 480 nm). .. Then, the integrated value of the amount of light in the first wavelength band of the first multicolor spectrum light 25 and the integrated value of the amount of light in the first wavelength band of the continuous spectrum light 26 of the xenon lamp match, and the integrated value of the amount of light in the first wavelength band of the first multicolor spectrum light 25 The light amount ratio Kv: Kb of V light and B light is determined so as to match the light amount integrated value of the second wavelength band with the light amount integrated value of the second wavelength band of the continuous spectrum light 26 of the xenon lamp.

Let Vb1 and Vb2 be the integrated values of the first and second wavelength bands of the V light, and Bb1 and Bb2 be the integrated values of the first and second wavelength bands of the B light. Further, the integrated values of the amount of light in the first and second wavelength bands of the continuous spectrum light 26 are set to Xb1 and Xb2. The integrated light amount Vb1 in the first wavelength band of V light is calculated by integrating the product of the spectral spectrum of V light and the spectral spectrum of the B color filter in the first wavelength band. Since the spectral spectrum of V light and the spectral spectrum of the B color filter are known, the integrated light amount Vb1 in the first wavelength band of V light is a known amount. The same applies to the other light intensity integral values Vb2, Bb1, Bb2, Xb1 and Xb2.

Therefore, the light intensity ratio Kv: Kb of V light and B light can be calculated by the equation (2). In this embodiment, as shown in FIG. 7, Kv: Kb≈0.53: 1 (≈0.35: 0.65).

第１多色スペクトル光２５を形成するＶ光とＢ光の光量比Ｋｖ：Ｋｂが定まれば、この光量比で合成したＶ光とＢ光の合成光を擬似的に青色光（以下、Ｂ２光という）として扱うことができる（図７参照）。

Once the light amount ratio Kv: Kb of the V light and the B light forming the first multicolor spectrum light 25 is determined, the combined light of the V light and the B light synthesized by this light amount ratio is simulated as blue light (hereinafter, B2). It can be treated as (referred to as light) (see FIG. 7).

Therefore, the light intensity integrated value obtained by receiving B2 light with B pixel is B2b, the light intensity integrated value obtained by receiving B2 light with G pixel is B2g, and the light intensity integrated value obtained by receiving B2 light with R pixel is B2r. Assuming that the light intensity ratio of the B2 light, the G light, and the R light forming the first multicolor spectrum light 25 is Pb2: Pg: Pr, the light intensity ratio of the B2 light, the G light, and the R light is determined by the equation (3). Pb2: Pg: Pr can be calculated. In this embodiment, Pb2: Pg: Pr = 1: 1.64: 1.65 (≈0.24: 0.36: 0.40).

こうして第１多色スペクトル光２５を形成するＶ光とＢ光の光量比Ｋｖ：Ｋｂと、Ｂ２光、Ｇ光、及びＲ光の光量比Ｐｂ２：Ｐｇ：Ｐｒが定まれば、これらを用いて第１多色スペクトル光２５を形成するＶ光、Ｂ光、Ｇ光、及びＲ光の光量比Ｃｖ：Ｃｂ：Ｃｇ：Ｃｒを算出することができる。本実施形態では、Ｃｖ：Ｃｂ：Ｃｇ：Ｃｒ＝Ｋｖ／Ｋｂ：１：Ｐｇ／Ｐｂ２：Ｐｒ／Ｐｂ２＝０．５３：１：１．６４：１．６５（≒０．１１：０．２２：０．３２：０．３６）である。

If the light amount ratio Kv: Kb of the V light and the B light forming the first multicolor spectrum light 25 and the light amount ratio Pb2: Pg: Pr of the B2 light, the G light, and the R light are determined in this way, these are used. The light amount ratio Cv: Cb: Cg: Cr of V light, B light, G light, and R light forming the first multicolor spectrum light 25 can be calculated. In this embodiment, Cv: Cb: Cg: Cr = Kv / Kb: 1: Pg / Pb2: Pr / Pb2 = 0.53: 1: 1.64: 1.65 (≈0.11: 0.22: 0.32: 0.36).

The first multicolor spectral light 25 is a multicolor spectral light obtained by synthesizing V light, B light, G light, and R light with the light amount ratio Cv: Cb: Cg: Cr (see FIG. 3). The endoscope system 10 uses the first multicolor spectral light 25 in which the light amount ratios of V light, B light, G light, and R light are set to the above light amount ratio Cv: Cb: Cg: Cr. The ratio of the integrated light amount for each color obtained by receiving the color spectrum light 25 by the pixels of the plurality of colors of the image sensor 48 is the ratio of the continuous spectrum light 26 of the xenon lamp received by the pixels of the plurality of colors of the image sensor 48, respectively. It matches the ratio of the integrated light amount for each color to be obtained.

Specifically, as can be seen from the equation (1) , for example, the light intensity integrated value (CvVb + CbBb + CgGb + CrRb) in the B pixel with respect to the light intensity integrated value (CvVg + CbBg + CgGg + CrRg) in the G pixel when the first multicolor spectral light 25 is used. (CvVb + CbBb + CgGb + CrRb) / (CvVg + CbBg + CgGg + CrRg) corresponds to the ratio Xb / Xg of the light intensity integrated value Xb in the B pixel to the light intensity integrated value Xg in the G pixel when the continuous spectrum light 26 of the xenon lamp is used. And the ratio of the integrated light intensity (CvVr + CbBr + CgGr + CrRr) to the integrated light intensity (CvVg + CbBg + CgGg + CrRg) in the G pixel when the first multicolor spectral light 25 is used (CvVr + CbBr + CgGr + CrRr) It corresponds to the ratio Xr / Xg of the light intensity integrated value Xr in the R pixel to the light intensity integrated value Xg in the G pixel when the spectral light 26 is used.

That is, when the first multicolor spectral light 25 is used, the balance of the image signal obtained from the image sensor 48 for each color is substantially the same as when the continuous spectrum light 26 of the xenon lamp is used. Therefore, in the endoscope system 10, the appearance of the observation target is substantially the same as when the continuous spectrum light 26 of the xenon lamp is used. Further, there is no need to recalculate the gain and matrix used in various signal processing performed by the DSP 56, noise removal processing performed by the noise removing unit 58, various image processing performed by the image generation unit 62, etc., and the same gain and matrix as before can be obtained. Since it can be used, the noise is almost the same as when the continuous spectrum light 26 of the xenon lamp is used.

Therefore, as in the present embodiment, the image sensor 48 has a B pixel (first color pixel) having sensitivity to blue (first color) and a G pixel (second color pixel) having sensitivity to green (second color). ) And R pixels (third color pixels) having sensitivity to red (third color), the light source control unit 22 sets V light, B light, G light, and R light into the above-mentioned light amount ratio Cv. : Cb: Cg: The ratio of the blue light intensity integrated value obtained by the B pixel and the light intensity integrated value of the second color obtained by the G pixel by emitting light with Cr is continuous with the case of using the first multicolor spectrum light 25. The ratio of the red light intensity integrated value and the green light intensity integrated value obtained by the R pixel is matched between the case where the spectral light 26 is used and the case where the first multicolor spectral light 25 is used and the continuous spectral light 26 is used. Match with the case.

Compared with the continuous spectrum light 26 of the xenon lamp, the first multicolor spectrum light 25 has less wavelength components in a part of the wavelength band (wavelength band between V light and B light, etc.), but so-called surface blood vessels and pits. Information on the structure near the surface layer of the mucous membrane such as a pattern and information on the structure of the mid-deep layer under the mucous membrane such as middle-deep blood vessels are sufficiently supported by each color light forming the first multicolor spectrum light 25. Therefore, in the endoscope system 10, by using the first multicolor spectrum light 25, the appearance of the observation target including the appearance of such surface blood vessels is almost the same as the case where the continuous spectrum light 26 of the xenon lamp is used. Match. Conversely, among the continuous spectrum light 26 of the xenon lamp, the light in the wavelength band between the V light and the B light brightens the endoscopic image, but each color forming the first multicolor spectrum light 25. Compared with light, it contributes less to the appearance of the structure of the object to be observed, such as surface blood vessels and mid-deep blood vessels. Therefore, there is no shortage of the first multicolor spectrum light 25 for endoscopic observation.

The ratio of the integrated light amount for each color obtained by receiving the first multicolor spectrum light 25 by the pixels of the plurality of colors of the image sensor 48 is the color obtained by receiving the continuous spectrum light 26 by the pixels of the plurality of colors. An error of at least 5% to 10% can be tolerated with respect to the ratio of each light amount integrated value. The visual sense may be relatively insensitive to the difference in color difference, and if the error is about the above, the appearance of the observation target will be almost the same as when the continuous spectrum light 26 of the xenon lamp is used, so each ratio is It can be considered that they are almost the same. Therefore, the ratio of the integrated value of the amount of light for each color obtained by receiving the first multicolor spectrum light 25 by the pixels of the plurality of colors of the image sensor 48 and the continuous spectrum light 26 are the pixels of the plurality of colors. The "match" of the ratio of the integrated values of the amount of light for each color obtained by receiving light in each of the above includes "almost match" including the above error.

[Second Embodiment]
The observation target of the endoscope system 10 is, for example, the esophagus, and the reflectance of the esophagus differs for each wavelength as shown in FIG. Therefore, as shown in FIG. 9, even when the multicolor spectral light 201 in which the maximum values of V light, B light, G light, and R light are standardized to "1" is used, the return light 202 from the esophagus is used. Changes to reflect the reflectance of the esophagus. Similarly, as shown in FIG. 10, even when the continuous spectrum light 26 of the xenon lamp is used, the return light 203 from the esophagus changes from the original continuous spectrum light 26 reflecting the reflectance of the esophagus. The reflectance of the esophagus includes not only the amount of light reflected from the esophagus but also the amount of fluorescence generated from tissues forming the mucous membrane of the esophagus. Therefore, the return light 202 includes not only the reflected light of the multicolor spectrum light 201 but also the fluorescence generated from the esophagus by irradiating the multicolor spectrum light 201. The same applies to the return light 203.

As described above, the return light 202 and the return light 203 from the esophagus change depending on the reflectance of the esophagus. Therefore, in the second embodiment, the light source control unit 22 irradiates the esophagus with the multicolor spectrum light 201. The ratio of the integrated light amount for each color obtained by receiving the return light 202 of the image sensor 48 with the pixels of the plurality of colors receives the continuous spectrum light 26 of the xenon lamp irradiating the esophagus with the pixels of the image sensor 48. The light amount ratios of V light, B light, G light, and R light are controlled so as to match the ratio of the light amount integrated values for each color obtained.

In this way, the integrated value of the amount of light for each color obtained by receiving the return light from the esophagus with the pixels of the plurality of colors of the image sensor 48 is received by the plurality of pixels of the image sensor 48 with the continuous spectrum light 26 of the xenon lamp. The multicolor spectrum light 225 shown in FIG. 11 is the multicolor spectrum light that matches the ratio of the integrated light amount for each color to be obtained. Graph 226 is the return light from the esophagus of the first multicolor spectral light 225.

Data of return light 202 and return light 203 instead of V light, B light, G light, R light, and continuous spectrum light 26 when calculating each light amount integrated value used in the formulas (1) to (3). Is used to calculate the light amount ratio Cv: Cb: Cg: Cr of V light, B light, G light, and R light forming the first multicolor spectrum light 225 in the same manner as in the first embodiment. it can. Specifically, in the case of the first multicolor spectral light 225, Cv: Cb: Cg: Cr = 0.53: 1: 1.36: 1.33 (≈0.13: 0.24: 0.32: 0.32). In the case of the first multicolor spectrum light 225, Kv: Kb = 1.05: 1.98 (≈0.35: 0.65), and Pb2: Pg: Pr = 2.02: 2.75 :. It is 2.69 (= 0.27: 0.37: 0.36).

As in the second embodiment, if the first multicolor spectrum light 225 in which the light amount ratios of V light, B light, G light, and R light are set in consideration of the properties of a specific observation target is used, a specific observation is performed. The appearance of the object is particularly accurate with the case of using the continuous spectrum light 26 of xenon.

The reflectance of the observation target differs depending on the type (site) of the observation target. For example, in addition to the esophagus, the stomach, large intestine, and the like are also observation targets of the endoscope system 10, but as shown in FIG. 12, the reflectance of each wavelength is different between the esophagus, stomach, and large intestine. Therefore, the light amount ratio of V light, B light, G light, and R light forming the first multicolor spectrum light 225 considering the reflectance of the esophagus and the first multicolor spectrum light considering the reflectance of the stomach are obtained. It is different from the light amount ratio of V light, B light, G light, and R light to be formed. Similarly, the light intensity ratios of V light, B light, G light, and R light that form the first multicolor spectrum light considering the reflectance of the large intestine are also different from those of the esophagus and stomach. Therefore, it is preferable to appropriately control the light amount ratios of V light, B light, G light, and R light that form the first multicolor spectrum light according to the type of observation target such as the esophagus, stomach, and large intestine.

In this case, as in the endoscope system 240 shown in FIG. 13, a light amount ratio storage unit 241 for storing a plurality of light amount ratios of V light, B light, G light, and R light is provided for each type of observation target. .. For example, the light amount ratio 251 for the esophagus, the light amount ratio 252 for the stomach, and the light amount ratio 253 for the large intestine are stored in advance in the light amount ratio storage unit 241. When the first multicolor spectral light that imitates the xenon lamp is used, the light source control unit 22 selects the light amount ratio according to the type of the observation target from the plurality of light amount ratios stored in the light amount ratio storage unit 241. Then, the light amount ratios of V light, B light, G light, and R light are controlled to the selected light amount ratio. When the observation target is the stomach, the light source control unit 22 selects the gastric light amount ratio 252 from the light amount ratio storage unit 241 and selects the light amount ratios of V light, B light, G light, and R light for the stomach light amount ratio 252. To control. In this way, the first multicolor spectrum light corresponding to the type of the observation target can be emitted.

In the endoscope system 240, the light amount ratio storage unit 241 is provided in the endoscope light source device 14, but the light amount ratio storage unit 241 may be provided in the processor device 16 or in the endoscope 12. Is also good. That is, if the light source control unit 22 can select an appropriate light amount ratio according to the type of the observation target, the place where the light amount ratio storage unit 241 is provided is arbitrary.

[Third Embodiment]
In the first embodiment and the second embodiment, the image sensor 48 having the primary color filter is used, but the endoscope systems 10 and 240 use the complementary color filter instead of the primary color image sensor 48. It is also possible to use a complementary color imaging sensor having the above. Complementary color filters include cyan color filters (Cy), magenta color filters (Mg), and yellow color filters (Ye). In the present embodiment, as shown in FIG. 14, the complementary color filter includes, for example, a green color filter (G) in addition to Cy, Mg, and Ye. That is, in the present embodiment, the image sensor 48 includes a cyan pixel (hereinafter referred to as Cy pixel), a magenta pixel (hereinafter referred to as Mg pixel), a yellow pixel (hereinafter referred to as Ye pixel), and a green pixel (hereinafter referred to as G pixel). ).

When a complementary color imaging sensor is used for the imaging sensor 48, the first multicolor spectral light that makes the appearance of the observation target substantially the same as when the continuous spectral light 26 of the xenon lamp is used is the first and second embodiments. The light amount ratios of V light, B light, G light, and R light are different from those of 1 multicolor spectrum light 25 and 225. Therefore, it is necessary to use the light intensity ratios of V light, B light, G light, and R light for complementary color imaging sensors instead of these.

The light amount integrated values obtained by receiving the V light forming the first multicolor spectrum light for the complementary color imaging sensor with the Cy pixel, Mg pixel, Ye pixel, and G pixel are Vcy, Vmg, Vye, and Vg, respectively. To do. Similarly, the integrated light amount obtained by receiving the B light forming the first multicolor spectrum light for the complementary color imaging sensor with the Cy pixel, Mg pixel, Ye pixel, and G pixel is Bcy, Bmg, Bye, respectively. And Bg, and the integrated values of the amount of light obtained by receiving the G light forming the first multicolor spectrum light for the complementary color imaging sensor with the Cy pixel, Mg pixel, Ye pixel, and G pixel are Gcy, Gmg, and Gye, respectively. , And Gg, and the integrated values of the amount of light obtained by receiving the R light forming the first multicolor spectrum light for the complementary color imaging sensor with the Cy pixel, Mg pixel, Ye pixel, and G pixel are Rcy, Rmg, respectively. Let it be Rye and Rg. The fact that these are known amounts is the same as in the first and second embodiments.

Further, the integrated light intensity value obtained by receiving the continuous spectrum light 26 of the xenon lamp with Cy pixels is defined as Xcy, and the integrated light intensity obtained by receiving the continuous spectrum light 26 of the xenon lamp with Mg pixels is defined as Xmg, and the continuous xenon lamps are continuously used. Let Xye be the integrated light amount obtained by receiving the spectral light 26 with the Ye pixels, and let Xg be the integrated light amount obtained by receiving the continuous spectral light 26 of the xenon lamp with the G pixels. The fact that these are known amounts is the same as in the first and second embodiments.

Then, the light amount ratios of the V light, the B light, the G light, and the R light forming the first multicolor spectrum light for the complementary color imaging sensor are V light: B as in the first and second embodiments. Light: G light: R light = Cv: Cb: Cg: Cr. These Cv, Cb, Cg, and Cr values are variables, and the ratio of the integrated light amount obtained by receiving the first multicolor spectral light for the complementary color imaging sensor with each complementary color pixel is the continuous xenon lamp. It is determined so as to match the ratio of the integrated light amount obtained by receiving the spectral light 26 at each pixel of the complementary color system. That is, the light amount ratios Cv: Cb: Cg: Cr of V light, B light, G light, and R light forming the first multicolor spectral light for the complementary color imaging sensor satisfy the equation (4). You just have to decide. In equation (4) , since the number of equations and the number of variables are equal, it can be solved to obtain the light amount ratios of V light, B light, G light, and R light Cv: Cb: Cg: Cr.

あるいは、以下に説明する算出方法によっても、補色系カラー撮像センサ用の第１多色スペクトル光を形成するＶ光、Ｂ光、Ｇ光、及びＲ光の光量比Ｃｖ：Ｃｂ：Ｃｇ：Ｃｒを算出することができる。

Alternatively, the light amount ratios Cv: Cb: Cg: Cr of V light, B light, G light, and R light forming the first multicolor spectral light for the complementary color imaging sensor can also be obtained by the calculation method described below. Can be calculated.

In this case, as shown in FIG. 15, the sensitivities of the Cy, Mg, Ye, and G color filters are added up for each wavelength to obtain the total sensitivity Sum of the complementary color image sensor, and the complementary color image sensor is integrated. It is regarded as one pixel having a color filter having a sensitivity of Sum (hereinafter referred to as S pixel).

Next, the wavelength bands are the first wavelength band of V light (wavelength 380 nm or more and less than 430 nm), the second wavelength band of B light (wavelength 430 nm or more and less than 480 nm), and the third wavelength band of G light (wavelength 480 nm or more and 580 nm). (Less than) and the fourth wavelength band of R light (wavelength 580 nm or more and less than 700 nm), and the amount of light obtained by receiving V light that forms the first multicolor spectrum light for a complementary color imaging sensor with S pixels. Of the integrated values, the integrated values of the amount of light in the first to fourth wavelength bands are VS1, VS2, VS3, and VS4, respectively.

Similarly, among the light quantity integrated values obtained by receiving the B light forming the first multicolor spectral light for the complementary color imaging sensor with the S pixel, the light quantity integrated values in the first to fourth wavelength bands are BS1 and BS1, respectively. BS2, BS3, and BS4, among the light amount integration values obtained by receiving the G light forming the first multicolor spectrum light for the complementary color imaging sensor with the S pixel, the light amount integration in the first to fourth wavelength bands. The values are GS1, GS2, GS3, and GS4, respectively, and among the light quantity integrated values obtained by receiving the R light forming the first multicolor spectral light for the complementary color imaging sensor with the S pixel, the first 1st Let RS1, RS2, RS3, and RS4 be the integrated values of the amount of light in the fourth wavelength band, respectively. Further, among the integrated light intensity values obtained by receiving the continuous spectrum light 26 of the xenon lamp with the S pixel, the integrated light intensity values in the first to fourth wavelength bands are XS1, XS2, XS3, and XS4, respectively.

The light intensity integrated value VS1 is calculated by integrating the product of the spectral spectrum of V light and the total sensitivity Sum for each wavelength in the range of the first wavelength band. The same applies to the other light intensity integrated values VS2, VS3, VS4, BS1, BS2, BS3, BS4, GS1, GS2, GS3, GS4, RS1, RS2, RS3, RS4, XS1, XS2, XS3, and XS4.

Then, instead of the formula (4) , the light amount ratio Cv: Cb of the V light, the B light, the G light, and the R light forming the first multicolor spectral light for the complementary color imaging sensor is performed by the formula (5). : Cg: Cr is calculated. In the case of the complementary color image sensor having the complementary color filter of FIG. 14 used in this embodiment, the light amount ratio obtained by the equation (5) is Cv: Cb: Cg: Cr ≈ 0.12: 0.23: 0. 27: 0.39. The multicolor spectral light shown in FIG. 16 is the first multicolor spectral light 325 for a complementary color imaging sensor formed by V light, B light, G light, and R light having a light amount ratio obtained by the equation (5). is there.

補色系カラー撮像センサ用の第１多色スペクトル光３２５を形成するＶ光、Ｂ光、Ｇ光、及びＲ光の光量比Ｃｖ：Ｃｂ：Ｃｇ：Ｃｒの式（５）による算出方法は、複数の波長帯域（第１〜第４波長帯）で、第１多色スペクトル光を補色系カラー撮像センサの複数色の画素でそれぞれ受光して得る色毎の光量積分値の合計値を、キセノンランプの連続スペクトル光２６を補色系カラー撮像センサの複数色の画素でそれぞれ受光して得る色毎の光量積分値の合計値と一致させる算出方法である。式（５）の算出方法は、式（４）の算出方法に比べて、色毎の光量積分値の比率に誤差が発生するが、その代わりに、確実にＣｖ＞０、Ｃｂ＞０、Ｃｇ＞０、かつＣｒ＞０を満たす範囲内でＣｖ、Ｃｂ、Ｃｇ、及びＣｒを決定できる利点がある。第１多色スペクトル光３２５を補色系カラー撮像センサの複数の画素で受光して得る色毎の光量積分値の比率は、キセノンランプの連続スペクトル光２６を補色系カラー撮像センサの複数の画素で受光して得る色毎の光量積分値の比率と実質的に一致し、これらの誤差は例えば数％程度である。

There are a plurality of calculation methods according to the formula (5) of the light amount ratios Cv: Cb: Cg: Cr of V light, B light, G light, and R light forming the first multicolor spectrum light 325 for the complementary color imaging sensor. In the wavelength band (1st to 4th wavelength bands), the total value of the integrated light amount for each color obtained by receiving the first multicolor spectrum light with the pixels of multiple colors of the complementary color imaging sensor is calculated by the xenon lamp. This is a calculation method in which the continuous spectrum light 26 of the above is matched with the total value of the integrated light amount for each color obtained by receiving light from the pixels of a plurality of colors of the complementary color imaging sensor. Compared with the calculation method of the formula (4) , the calculation method of the formula (5) causes an error in the ratio of the integrated light quantity for each color, but instead, Cv> 0, Cb> 0, Cg are surely generated. There is an advantage that Cv, Cb, Cg, and Cr can be determined within a range where> 0 and Cr> 0 are satisfied. The ratio of the integrated light amount for each color obtained by receiving the first multicolor spectrum light 325 with a plurality of pixels of the complementary color imaging sensor is such that the continuous spectrum light 26 of the xenon lamp is received by the plurality of pixels of the complementary color imaging sensor. It substantially matches the ratio of the integrated light amount for each color obtained by receiving light, and these errors are, for example, about several%.

Therefore, as in the present embodiment, the image sensor 48 has a Cy pixel (first color pixel) that is sensitive to cyan (first color) and an Mg pixel (third color) that is sensitive to magenta (third color). When having a Ye pixel (fourth color pixel) having sensitivity to yellow (fourth color) and a G pixel (second color pixel) having sensitivity to green (second color), the light source control unit 22 Is the integrated value of cyan light obtained by Cy pixels and the integrated value of green light obtained by G pixels by emitting V light, B light, G light, and R light with the above light amount ratio Cv: Cb: Cg: Cr. The ratio of and is matched between the case where the first multicolor spectrum light 25 is used and the case where the continuous spectrum light 26 is used, and the ratio of the magenta light amount integrated value and the green light amount integrated value obtained by the Mg pixel is the first. The ratio of the integrated value of the amount of yellow light and the integrated value of the amount of green obtained by the Ye pixels is set to match the case where the multicolor spectrum light 25 is used and the case where the continuous spectrum light 26 is used, and the first multicolor spectrum light 25 is used. The case of using the continuous spectrum light 26 and the case of using the continuous spectrum light 26 are matched.

The method of calculating the light amount ratio according to the formula (5) of the third embodiment can also be applied to the case where the primary color system color image sensor is used for the image sensor 48. Among the primary color imaging sensors, in addition to B pixels, G pixels, and R pixels, there are also sensors having E pixels having an emerald color filter and sensors having white pixels (W pixels) not provided with a color filter. is there. When these primary color system color imaging sensors are used, the method of calculating the light intensity ratio of the formula (5) may be more preferable than the method of calculating the light intensity ratio of the formula (4).

Even when a complementary color image sensor is used for the image sensor 48 as in the third embodiment, V light, B, which forms the first multicolor spectrum light in consideration of the observation target as in the second embodiment. It is preferable to control the light amount ratio Cv: Cb: Cg: Cr of light, G light, and R light.

As shown in the formula (2) of the first embodiment and the formula (5) of the third embodiment, one pixel receives the light in the wavelength band emitted by the light sources of a plurality of colors in the first multicolor spectrum light. In this case, for each wavelength band of light received by one pixel (that is, for each wavelength band of light emitted by each light source), the integrated light amount value matches the integrated light amount obtained by receiving the continuous spectrum light 26 of the xenon lamp. Then, the light amount ratios Cv: Cb: Cg: Cr of V light, B light, G light, and R light forming the first multicolor spectrum light can be appropriately determined. This method is particularly effective when the number of colors of the light source is larger than the number of colors of the pixels (see the formula (2) of the first embodiment).

[Fourth Embodiment]
In the first to third embodiments, the light source control unit 22 uses the LEDs 20a to 20d of the light source unit 20 to imitate the case where the continuous spectrum light 26 of the xenon lamp is used. Although the 325 is generated, the light source control unit 22 switches between the first multicolor spectrum light 25, 225, and 325 by the LEDs 20a to 20d of the light source unit 20, and the first multicolor spectrum light 25 and the xenon lamp. A second multicolor spectrum light having a second multicolor spectrum different from that of the continuous spectrum light 26 may be generated.

The second multicolor spectral light is illumination light having a unique spectral spectrum that is not found in conventional endoscopic systems using xenon lamps. For example, as shown in FIG. 17, the light source control unit 22 makes the amount of light of at least one of V light and B light (V light in this embodiment) larger than that of the first multicolor spectrum light 25. That is, the integrated light quantity obtained by receiving the second multicolor spectral light 401 with the B pixel is made larger than the integrated light quantity obtained by receiving the first multicolor spectral light 25 with the B pixel. Further, in the present embodiment, only the amount of V light forming the second multicolor spectrum light 401 is changed with respect to the first multicolor spectrum light 25, but the second multicolor spectrum light 401 is further changed. It is preferable that the integrated light quantity obtained by receiving light received by the G pixel is smaller than the integrated light quantity obtained by receiving the first multicolor spectrum light 25 by the G pixel.

When the observation target is observed using the second multicolor spectral light 401, the blood vessels and pit patterns on the surface layer of the mucous membrane can be observed more clearly than when the continuous spectrum light 26 of the xenon lamp is used. Therefore, if the first multicolor spectrum light 25 and the second multicolor spectrum light 401 can be switched, the peculiar advantage of using the multicolor spectrum light as described above can be enjoyed.

The switching between the first multicolor spectrum light 25 and the second multicolor spectrum light 401 can be arbitrarily switched by using an observation mode changeover switch (not shown) provided on the operation unit 12b of the endoscope 12. However, in particular, it is preferable to automatically switch between the first multicolor spectrum light 25 and the second multicolor spectrum light 401 according to the model of the endoscope 12 used in the endoscope system 10.

In this way, when the first multicolor spectrum light 25 and the second multicolor spectrum light 401 are automatically switched depending on the model of the endoscope 12, the endoscope 12 is like the endoscope system 410 shown in FIG. Is provided with an ID storage unit 411 that stores an ID (Identification Data) indicating a model, and the endoscope light source device 14 is provided with an endoscope model detection unit 412. When the endoscope 12 is connected to the endoscope light source device 14, the endoscope model detection unit 412 reads the ID of the endoscope 12 from the ID storage unit 411, so that the connected endoscope 12 Is detected, and the detection result is input to the light source control unit 22. Then, the light source control unit 22 uses the first multicolor spectrum light 25 and the second multicolor spectrum light 25 to generate the illumination light generated by the light source unit 20 according to the model of the endoscope 12 detected by the endoscope model detection unit 412. Switch with 401. More specifically, when the model of the endoscope 12 is a model used in a conventional endoscope system using continuous spectrum light of a xenon lamp, the light source control unit 22 generates illumination generated by the light source unit 20. When the light is automatically set to the first multicolor spectrum light 25 and the model of the endoscope 12 is a model other than the above (in the case of a model used only in an endoscope system using multicolor spectrum light, etc.) It is preferable that the illumination light generated by the light source unit 20 is automatically set to the second multicolor spectrum light 401.

When connecting an endoscope used in a conventional endoscope system using a xenon lamp, doctors often want to be able to observe the observation target in the same way as a familiar conventional endoscope system, and multicolor spectral light is used. When connecting an endoscope used only in an endoscope system used as illumination light, doctors often desire observations that take advantage of multicolor spectral light. Therefore, as described above, if the illumination light is automatically switched between the first multicolor spectrum light 25 and the second multicolor spectrum light 401 depending on the model of the endoscope 12, no operation or setting is required. It is possible to automatically provide an endoscopic image that meets the needs. Of course, it is more preferable that the initial setting is automatically set according to the model of the endoscope 12 as described above, and then manually switched at the discretion of the doctor.

In the endoscope system 410 of FIG. 18, the endoscope light source device 14 detects the connection of the endoscope 12 by the endoscope model detection unit 412, and reads the ID from the endoscope 12 to read the ID of the endoscope 12. However, as in the endoscope system 420 shown in FIG. 19, the processor device 16 is provided with an ID reading unit 413, and the ID reading unit 413 detects the connection of the endoscope 12 and The ID may be read from the endoscope 12. In this case, the endoscope model detection unit 412 may acquire the ID of the endoscope 12 from the ID reading unit 413 of the processor device 16 and detect the model.

[Fifth Embodiment]
A semiconductor light source such as an LED has a longer life than a conventional light source such as a xenon lamp, but even a semiconductor light source such as an LED deteriorates over time as shown in FIG. Even if it is driven with the specified drive voltage, the amount of light decreases. In addition, the degree of deterioration over time varies depending on the type of semiconductor light source (wavelength of emitted light, etc.). If the deterioration with time is ignored, even if the light source control unit 22 performs the default control for emitting the first multicolor spectrum light 25, for example, the multicolor spectrum light that does not satisfy the condition of the first multicolor spectrum light 25 is emitted. It may be done. Therefore, it is preferable that the light source control unit 22 emits the first multicolor spectrum light 25 and the second multicolor spectrum light 401 in consideration of the deterioration of the LEDs 20a to 20d of the light source unit 20 with time.

In order to emit the first multicolor spectrum light 25 and the second multicolor spectrum light 401 that satisfy the conditions of the first embodiment and the like even if the LEDs 20a to 20d of the light source unit 20 are deteriorated with time as described above, For example, as in the endoscope system 500 shown in FIG. 21, the endoscope light source device 14 is provided with a light amount detection unit 501, and the light source control unit 22 is provided with a time-dependent deterioration detection unit 504.

The light amount detection unit 501 includes a V light amount detection unit 502a for detecting the light amount of V light, a B light amount detection unit 502b for detecting the light amount of B light, and a G light amount detection for detecting the light amount of G light. A unit 502c and an R light amount detecting unit 502d for detecting the light amount of R light are provided. The V light amount detecting unit 302a detects the light amount of the V light emitted by the V-LED 20a by acquiring a part of the V light through the mirror 503a. The mirror 503a is arranged in the optical path of the V-LED 20a, reflects a part of the V light emitted by the V-LED 20a to be incident on the V light amount detection unit 502a, and causes the remaining V light to the optical path coupling unit 23. It is transparent toward. Similarly, in the optical path of the B-LED20b, G-LED20c, and R-LED20d, a part of each color light emitted by these is reflected, and the B light amount detection unit 502b, the G light amount detection unit 502c, and the R light amount detection A mirror 503b, a mirror 503c, and a mirror 503d that are incident on the unit 502d and transmit the remaining colored light toward the optical path coupling unit 23 are arranged. The B light amount detection unit 502b acquires a part of the B light through the mirror 503b and detects the light amount of the B light emitted by the B-LED 20b. The G light amount detection unit 502c acquires a part of the G light through the mirror 503c and detects the light amount of the G light emitted by the G-LED 20c. The R light amount detection unit 502d acquires a part of the R light through the mirror 503d and detects the light amount of the R light emitted by the R-LED 20d.

The light amount detection unit 501 inputs the light amounts of V light, B light, G light, and R light detected by the light amount detection units 502a to 502d for each color to the light source control unit 22. In the light source control unit 22, the time-dependent deterioration detection unit 504 determines the drive conditions such as the drive current of each of the LEDs 20a to 20d that emits the first multicolor spectrum light 25, and the light amount of each color light actually detected by the light amount detection unit 501. And, the deterioration with time of each LED 20a to 20d is detected. Specifically, the aged deterioration detection unit 504 detects the most deteriorated light source having the lowest light amount with respect to a predetermined light amount among the LEDs 20a to 20d. The light source control unit 22 sets the amount of light of the remaining light source according to the amount of light of the most deteriorated light source detected by the time-dependent deterioration detection unit 504. For example, as shown in FIG. 22, although the light source control unit 22 drives the LEDs 20a to 20d under the driving conditions for emitting the first multicolor spectrum light 25, the light amount of the LEDs 20a to 20d is specified. Due to the deterioration of the R-LED 20d over time, the amount of R light is less than the specified amount of light forming the first multicolor spectrum light 25, and the V light, B light, and G light are the first multicolor spectrum light 25. It is assumed that the specified amount of light forming the above is the emitted multicolor spectrum light 524. In this case, in the light source control unit 22, the time-dependent deterioration detection unit 504 detects the R-LED 20d as the most deteriorated light source. Therefore, as shown in FIG. 23, the light source control unit 22 deteriorates with time by reducing the amount of V light, B light, and G light according to the amount of R light emitted by the R-LED 20d. A new first multicolor spectrum light 525 in which the amount of R light emitted by the R-LED 20d and the amount of light of V light, B light, and G light are balanced is emitted. That is, when a shortage of light intensity is detected in at least one of the LEDs 20a to 20d, the light source control unit 22 sets the light intensity of each LED 20a to 20d forming the first multicolor spectral light 25 with respect to the specified value. , Set the light amount of the remaining light source according to the light amount of the most deteriorated light source with the largest shortage of light amount. As a result, the first multicolor spectrum light 525 in which the balance of each color light is maintained is emitted.

As described above, by detecting the amount of light of each color light emitted by each of the LEDs 20a to 20d and setting the amount of light of the remaining light source according to the amount of light of the light source that has deteriorated most over time among these LEDs 20a to 20d, the light source The control unit 22 can stably emit the first multicolor spectrum light 25 and the second multicolor spectrum light 401 in which the balance of each color light is always maintained by the light source unit 20. Further, according to the above, the first multicolor spectrum lights 25 and 325 and the second multicolor spectrum light 401 in which the balance of each color light is always maintained are stably emitted, so that the matrix used in the matrix processing or the like is used. , It is not necessary to recalculate the signal processing parameters and image processing parameters used to generate the endoscopic image, or to prepare a plurality of them. If the color filter of the image sensor 48 has color mixing, the signal processing parameters and image processing parameters used to generate the endoscopic image can be recalculated or corrected even if a plurality of them are prepared. Although it cannot be cut off, if the above is done, the observation target can always be observed stably.

It is preferable that the light amount detection of each color light performed by the light amount detection unit 501 in the fifth embodiment is performed at least at the time of calibration. In particular, the light amount detection unit 501 repeatedly detects the light amount of each color light while each of the LEDs 20a to 20d emits light for observing the observation target, feeds back to the light source control unit 22, and makes the first multiple in real time. It is preferable to adjust the balance of the color spectrum light 25 and the like.

[Sixth Embodiment]
In the endoscope system 500 of the fifth embodiment, the deterioration with time of the LEDs 20a to 20d is detected, but the light source control unit 22 accurately detects the first multicolor spectral light due to factors other than the deterioration with time of the LEDs 20a to 20d. In some cases, 25 cannot emit light. In this case, as in the endoscope system 600 shown in FIG. 24, a light amount detection unit 501 or the like similar to the endoscope system 500 of the fifth embodiment is provided, and the light source control unit 22 replaces the time-dependent deterioration detection unit 504. Is provided with a verification unit 604.

The verification unit 604 stores in advance the ratio of the integrated light amount for each color obtained by receiving the continuous spectrum light 26 of the xenon lamp to be imitated by the pixels of each color of the image sensor 48 in the imitation ratio table 606. The verification unit 604 uses the imitation ratio table 606 and the detection results of the light amount detection unit 501 to receive the first multicolor spectral light 25 actually emitted by the pixels of a plurality of colors, and obtains the integrated light amount for each color. It is verified whether or not the ratio of is consistent with the ratio of the integrated light amount for each color obtained by receiving the continuous spectrum light 26 of the xenon lamp with the pixels of a plurality of colors.

The verification unit 604 calculates the light amount integrated value of each color pixel from the actual light amount of each LED 20a to 20d, which is the detection result of the light amount detection unit 501, and the spectral characteristics of the color filter of the image sensor 48, and obtains the ratio thereof. For example, when the image sensor 48 is a primary color color imaging sensor having B pixels, G pixels, and R pixels, the ratio of the light amount integrated value obtained by the B pixel to the light amount integrated value obtained by the G pixel (hereinafter, in the present embodiment). Bp / Gp) and the ratio of the integrated light amount obtained by the R pixel to the integrated light amount obtained by the G pixel (hereinafter, referred to as Rp / Gp in the present embodiment) are calculated.

Further, the light intensity integrated value of each color pixel is calculated in advance from the continuous spectrum light 26 of the xenon lamp to be imitated and the spectral characteristics of the color filter of the image sensor 48, and the mimicry ratio table 606 shows the case where the imitated continuous spectrum light 26 is used. The ratio of the light intensity integrated value obtained by the B pixel to the light intensity integrated value obtained by the G pixel (hereinafter referred to as Bx / Gx in the present embodiment) and the light intensity integrated value obtained by the G pixel when the imitating continuous spectrum light 26 is used. The integrated value of the amount of light obtained by the R pixel (hereinafter referred to as Rx / Gx in the present embodiment) is stored.

Therefore, the verification unit 604 compares the calculated ratio Bp / Gp with the ratio Bx / Gx stored in the imitation ratio table 606, and stores the calculated ratio Rp / Gp and the imitation ratio table 606. Compare the ratios Rx / Gx. As a result of these two comparisons, the error of the ratio Bp / Gp with respect to the ratio Bx / Gx is within the permissible range (for example, about 10% or less of the ratio Bp / Gp), and the ratio Rp with respect to the ratio Rx / Gx. If the error of / Gp is within the permissible range (for example, about 10% or less of the ratio Bx / Gx), it is determined that the first multicolor spectrum light 25 is emitting properly. In this case, the light source control unit 22 continues to emit the first multicolor spectral light 25.

On the other hand, when the error of the ratio Bp / Gp with respect to the ratio Bx / Gx is out of the permissible range, or when the error of the ratio Rp / Gp with respect to the ratio Rx / Gx is out of the permissible range, the verification unit 604 It is determined that the appropriate first multicolor spectrum light 25 is not emitted. In this case, the light source control unit 22 feedback-controls the LEDs 20a to 20d using the verification result of the verification unit 604. That is, each LED 20a to the light source control unit 22 is based on the error of the ratio Bp / Gp with respect to the ratio Bx / Gx calculated by the verification unit 604 or the error of the ratio Rp / Gp with respect to the ratio Rx / Gx. The amount of light of 20d is adjusted and controlled. As a result, the illumination light is always corrected to the appropriate first multicolor spectrum light 25.

In the endoscope system 600 of the sixth embodiment, the verification unit 604 does not consider the type of the observation target when calculating the light intensity integrated value of each color, but the type of the observation target is the same as in the second embodiment. In consideration of the above, the light intensity integrated value and the ratio of the light intensity integrated values of each color calculated by the verification unit 604 can be calculated. Further, the verification unit 604 of the endoscope system 600 of the sixth embodiment can also function as the time-dependent deterioration detection unit 504 of the fifth embodiment. In the sixth embodiment, the verification unit 604 is provided in the endoscope light source device 14, but the verification unit 604 may be provided in the processor device 16.

The endoscope system 600 of the sixth embodiment verifies whether the illumination light is the first multicolor spectrum light 25 by using the detection result of the light amount detection unit 501, but the detection of the light amount detection unit 501 Instead of using the result, it is also possible to verify whether the illumination light is the first multicolor spectrum light 25 by using the output of the image pickup sensor 48. In this case, as in the endoscope system 700 shown in FIG. 25, the processor device 16 is provided with the verification unit 704.

The verification unit 704 is the same as the verification unit 604 of the sixth embodiment except that the output of the image sensor 48 acquired from the reception unit 53 is used instead of the detection result of the light amount detection unit 501. That is, the verification unit 704 stores in the imitation ratio table 706 the ratio of the integrated light amount for each color obtained by receiving the continuous spectrum light 26 of the xenon lamp to be imitated by the pixels of each color of the image sensor 48. Using the copy ratio table 706 and the output of the image sensor 48, the ratio of the light intensity integrated value for each color obtained by receiving the first multicolor spectral light 25 actually emitted by the pixels of a plurality of colors is the ratio of the xenon lamp. It is verified whether or not the ratio of the integrated light amount for each color obtained by receiving the continuous spectrum light 26 with the pixels of a plurality of colors matches.

The verification unit 704 acquires an image signal, which is the output of the image pickup sensor 48, from the reception unit 53, and obtains a ratio thereof. When the image sensor 48 is a primary color color image sensor having B pixels, G pixels, and R pixels, for example, the verification unit 704 has an average value of each of the B image signal, the G image signal, and the R image signal (average value). The integrated value of the amount of light of the pixels of each color is calculated by obtaining (statistics such as median and median), and the ratio Bp / Gp and the ratio Rp / Gp are calculated. The average value of the image signals of each color calculated by the verification unit 704 is affected by the gain applied when reading the signal charge from the image sensor 48 and the specific contents of various processes performed by the receiving unit 53. Although it is not the light intensity integrated value itself, the same processing is always performed in the xenon emulate mode that emits the first multicolor spectrum light 25, so that the average value of the image signals of each color and the like substantially represents the light intensity integrated value.

The imitation ratio table 706 stores the ratio Bx / Gx and the ratio Rx / Gx calculated by using the average values of the B image signal, the G image signal, and the R image signal when the continuous spectrum light 26 to be imitated is used. To do. The verification unit 704 compares the calculated ratio Bp / Gp with the ratio Bx / Gx stored in the imitation ratio table 706, and compares the calculated ratio Rp / Gp with the ratio Rx / stored in the imitation ratio table 606. Gx is compared, and the light source control unit 22 controls the LEDs 20a to 20d based on these comparison results (verification result of the verification unit 704), which is the same as the endoscope system 600 of the sixth embodiment.

It should be noted that verification can be performed by the verification unit 704 while photographing the actual observation target, but in order to eliminate the influence of individual differences of the observation target, for example, a simulated body (phantom) that imitates the reflectance of the biological mucous membrane. It is preferable to take a picture of a white plate that allows the illumination light to be incident on the image sensor 48 almost directly for verification.

The endoscopic system 700 of the above modification does not consider the type of observation target when the verification unit 704 calculates the integrated light intensity value of each color, but considers the type of observation target as in the second embodiment. Then, the light intensity integrated value and the ratio of the light intensity integrated values of each color calculated by the verification unit 704 can be calculated. In this way, when considering the type of observation target in the verification performed by the verification unit 704, a simulated body that imitates the reflectance of the esophagus, stomach, large intestine, etc. is used.

In the endoscope system 700 of the above modification, the verification unit 704 acquires an image signal from the receiving unit 53 as an output of the image sensor 48, but instead of acquiring the image signal from the receiving unit 53, the DPS 56 and noise An image signal can be acquired from the removal unit 58 or the image generation unit 62. The verification unit 704 may acquire the image signal from the A / D converter 51 of the endoscope 12, the CDS / AGC circuit 50, or the image sensor 48 instead of acquiring the image signal from each part of the processor device 16. ..

In the first to fifth embodiments, the B light emitted by the B-LED 20b is used as it is for the first multicolor spectrum lights 25, 225, 325, and 525, but the light having a wavelength of about 450 nm to about 500 nm is used. It reduces the contrast of structures such as surface blood vessels and pit patterns. Therefore, as in the endoscope system 800 shown in FIG. 26, the B-LED 20b can be made by arranging the band limiting unit 801 that reduces the light having a wavelength of about 450 nm to about 500 nm in the optical path of the B-LED 20b. It is preferable to generate Bs light having a reduced wavelength component of about 450 nm to about 500 nm from the emitted B light, and use the Bs light for the first multicolor spectrum lights 25, 225, 325, and 525. In this case, the light amount ratio is calculated using the spectral spectrum of Bs light after passing through the band limiting unit 801.

In the first to sixth embodiments, the present invention is carried out by an endoscope system in which an endoscope 12 provided with an image sensor 48 is inserted into a subject for observation. However, a capsule endoscope is used. The present invention is also suitable for systems. For example, as shown in FIG. 27, a capsule endoscopy system has at least a capsule endoscope 900 and a processor device (not shown).

The capsule endoscope 900 includes a light source unit 902, a light source control unit 903, an image sensor 904, an image generation unit 906, and a transmission / reception antenna 908. Similar to the light source unit 20 of the first to sixth embodiments, the light source unit 902 includes a V-LED that emits V light, a B-LED that emits B light, a G-LED that emits G light, and an R light. It has an R-LED that emits light.

The light source control unit 903 controls the drive of the light source unit 902 in the same manner as the light source control unit 22 of each of the above-described embodiments and modifications. Further, the light source control unit 903 can wirelessly communicate with the processor device of the capsule endoscopy system by the transmission / reception antenna 908. The processor device of the capsule endoscopy system is substantially the same as the processor device 16 of the first to sixth embodiments, but the image generation unit 906 is provided in the capsule endoscopy 900, and the generated endoscope image is provided. Is transmitted to the processor device via the transmission / reception antenna 908. The image sensor 904 is configured in the same manner as the image sensor 48 of the first to sixth embodiments.

In the first to sixth embodiments, the light source control unit 22 generates the first multicolor spectrum lights 25, 225, 325, and 525 for imitating the white light of the xenon lamp, but the xenon. Instead of the white light of the lamp, a first multicolor spectrum light may be generated to mimic other broadband continuous spectrum light. For example, in a conventional endoscope system, a halogen lamp other than a xenon lamp may be used. The first multicolor spectrum light for imitating a halogen lamp other than the xenon lamp may be generated, and the type of the lamp to be imitated may be selected by a doctor or the like. Similarly, it is possible to imitate the continuous spectrum light emitted by a broadband light source that combines an excitation light source that emits excitation light and a phosphor that emits fluorescence by irradiation of the excitation light, or a broadband light source composed of a semiconductor light source. Broadband light sources that irradiate a phosphor with excitation light include, for example, an excitation light light source that emits ultraviolet light, purple light, or blue light, and green to yellow (green to yellow) by irradiation with ultraviolet light, purple light, or blue light. Alternatively, it is composed of a combination of phosphors that emit fluorescence (red). A broadband light source composed of a semiconductor light source is, for example, a semiconductor light source that generates white light. As described above, when mimicking wideband continuous spectrum light other than the xenon lamp (including pseudo white light that looks substantially white and other non-white light), the white light of the xenon lamp of the above embodiment is also imitated. The first multicolor spectrum light can be generated in the same manner as in the above case.

In the first to sixth embodiments, four color LEDs of V-LED20a, B-LED20b, G-LED20c, and R-LED20d are used, but a plurality of light sources used in the endoscope light source device 14 emit light. The color (wavelength) and combination of light, the number of LEDs, and the like may be other colors and combinations. Further, instead of the LED, another semiconductor light source such as LD (Laser Diode) may be used. A light source that combines an LED or LD and a phosphor may be used.

In the first to sixth embodiments, the LEDs 20a to 20d of the light source unit 20 are all lit at the same time, but while the image sensor 48 is imaging the observation target (time during photoelectric conversion). Each of these LEDs 20a to 20d may be turned on in sequence. Further, while the image sensor 48 is imaging the observation target, the lighting time may be adjusted for each color to control the amount of light. In these cases as well, the same result as when the LEDs 20a to 20d of the light source unit 20 are turned on at the same time as in the first to fifth embodiments is obtained.

10,240,410,420,500,600,700,800 Endoscope system 20 Light source unit 22 Light source control unit 25,225,325,525 First multicolor spectrum light 26 Continuous spectrum light 412 Endoscope model detection unit 501 Light amount detection unit 504 Aging deterioration detection unit 604,704 Verification unit 900 Capsule endoscope

Claims (9)

A purple light source that emits V light, which is purple light in the first wavelength band, a blue light source that emits B light, which is blue light in the second wavelength band, a green light source that emits G light, which is green light in the third wavelength band, and A first multicolor spectrum light having a plurality of light sources having a red light source that emits R light, which is red light in the fourth wavelength band, and having a first multicolor spectrum obtained by superimposing the light emitted by the plurality of light sources. The light source that emits light
An imaging sensor having multiple color pixels that are sensitive to different colors, including Cy pixels that are sensitive to cyan, Mg pixels that are sensitive to magenta, Ye pixels that are sensitive to yellow, and Ye pixels that are sensitive to green. An image sensor with G pixels and
The ratio of the integrated light amount for each color obtained by controlling the plurality of light sources and receiving the first multicolor spectrum light by the pixels of the plurality of colors is the white color emitted by the xenon lamp, the halogen lamp, or the white LED. It is provided with a light source control unit that matches the ratio of the integrated light amount for each color obtained by receiving continuous spectrum light, which is light, with the pixels of the plurality of colors.
The light source control unit
For the image sensor, wherein Cy pixel, the Mg pixel, the Ye pixel, and In no event where deemed S pixels having an overall sensitivity Sum color filter of the the sum of sensitivity of G pixels for each wavelength, the V light Is obtained by integrating the product of the total sensitivity Sum of the S pixels for each wavelength in the range of the first wavelength band, the second wavelength band, the third wavelength band, and the fourth wavelength band, respectively. The integrated light amount to be obtained is VS1, VS2, VS3, VS4, and the spectral spectrum of the B light is the product of the total sensitivity Sum of the S pixels for each wavelength, which is the first wavelength band, the second wavelength band, and the third wavelength. The integrated light amount obtained by integrating in the band and the range of the fourth wavelength band is BS1, BS2, BS3, and BS4, and the spectral spectrum of the G light is the product of the total sensitivity Sum of the S pixels for each wavelength. The light quantity integrated values obtained by integrating in the ranges of the first wavelength band, the second wavelength band, the third wavelength band, and the fourth wavelength band are defined as GS1, GS2, GS3, and GS4, and the R By integrating the spectral spectrum of light for each wavelength of the total sensitivity Sum of the S pixels in the range of the first wavelength band, the second wavelength band, the third wavelength band, and the fourth wavelength band, respectively. The obtained light intensity integrated values are RS1, RS2, RS3, and RS4, and the product of the spectral spectra of the continuous spectrum light for each wavelength of the total sensitivity Sum of the S pixels is the first wavelength band, the second wavelength band, and the first. When the light quantity integrated values obtained by integrating in the three wavelength bands and the fourth wavelength band are set to XS1, XS2, XS3, and XS4, the V light, the V light, so as to satisfy the following equation (5). An endoscopic system that calculates the light amount ratio Cv: Cb: Cg: Cr of the B light, the G light, and the R light.

A light amount ratio storage unit for storing the light amount ratio Cv: Cb: Cg: Cr is provided for each type of observation target.
The endoscope system according to claim 1 , wherein the light source control unit selects a light amount ratio Cv: Cb: Cg: Cr from among the light amount ratios Cv: Cb: Cg: Cr for each type of observation target. A light amount detecting unit for detecting the amount of light emitted by the plurality of light sources is provided.
Using the detection result of the light amount detection unit, the light source control unit uses the detection result of the light amount detection unit to maximize the deterioration of the light amount with respect to the specified value of the light amount forming the first multicolor spectrum light among the plurality of light sources. The endoscopic system according to claim 1 or 2 , wherein the amount of light of the remaining light source is set according to the amount of light of the light source. The endoscope system according to claim 3 , wherein the light amount detecting unit repeatedly detects the light emitted by the plurality of light sources while the plurality of light sources are emitting light. The ratio of the light intensity integration value for each color obtained by receiving the first multicolor spectrum light by the pixels of the plurality of colors is the light intensity integration for each color obtained by receiving the continuous spectrum light by the pixels of the plurality of colors. The endoscopic system according to any one of claims 1 to 4 , further comprising a verification unit for verifying whether or not the ratio of values matches. A light amount detecting unit for detecting the amount of light emitted by the plurality of light sources is provided.
The verification unit uses the detection result of the light amount detection unit to obtain the continuous spectrum light by the ratio of the light amount integrated value for each color obtained by receiving the first multicolor spectral light by the pixels of the plurality of colors. The endoscope system according to claim 5 , wherein it is verified whether or not the ratio of the integrated light amount for each color obtained by receiving light from the pixels of the plurality of colors matches. The verification unit uses the output of the imaging sensor to receive the first multicolor spectral light with the pixels of the plurality of colors, and the ratio of the integrated value of the amount of light for each color is the plurality of continuous spectral lights. The endoscopic system according to claim 5 , wherein it is verified whether or not the ratio of the integrated light amount for each color obtained by receiving light received by each color pixel is matched. The endoscope system according to any one of claims 5 to 7 , wherein the light source control unit controls the plurality of light sources by using the verification result by the verification unit. A purple light source that emits V light, which is purple light in the first wavelength band, a blue light source that emits B light, which is blue light in the second wavelength band, a green light source that emits G light, which is green light in the third wavelength band, and A first multicolor spectrum light having a plurality of light sources having a red light source that emits R light, which is red light in the fourth wavelength band, and having a first multicolor spectrum obtained by superimposing the light emitted by the plurality of light sources. An imaging sensor having a light source unit that emits light and pixels of a plurality of colors having sensitivity to different colors, a Cy pixel having sensitivity to cyan, an Mg pixel having sensitivity to magenta, and a Ye pixel having sensitivity to yellow. In the method of operating an endoscopic system including an imaging sensor having G pixels having sensitivity to green.
The light source control unit controls the plurality of light sources, and sets the ratio of the integrated light amount for each color obtained by receiving the first multicolor spectrum light by the pixels of the plurality of colors with a xenon lamp, a halogen lamp, or white. This is a step of matching the ratio of the integrated light amount for each color obtained by receiving the continuous spectrum light, which is the white light emitted by the LED, with the pixels of the plurality of colors.
The light source control unit
For the image sensor, wherein Cy pixel, the Mg pixel, the Ye pixel, and In no event where deemed S pixels having an overall sensitivity Sum color filter of the the sum of sensitivity of G pixels for each wavelength, the V light Is obtained by integrating the product of the total sensitivity Sum of the S pixels for each wavelength in the range of the first wavelength band, the second wavelength band, the third wavelength band, and the fourth wavelength band, respectively. The integrated light amount to be obtained is VS1, VS2, VS3, VS4, and the spectral spectrum of the B light is the product of the total sensitivity Sum of the S pixels for each wavelength, which is the first wavelength band, the second wavelength band, and the third wavelength. The integrated light amount obtained by integrating in the band and the range of the fourth wavelength band is BS1, BS2, BS3, and BS4, and the spectral spectrum of the G light is the product of the total sensitivity Sum of the S pixels for each wavelength. The light quantity integrated values obtained by integrating in the ranges of the first wavelength band, the second wavelength band, the third wavelength band, and the fourth wavelength band are defined as GS1, GS2, GS3, and GS4, and the R By integrating the spectral spectrum of light for each wavelength of the total sensitivity Sum of the S pixels in the range of the first wavelength band, the second wavelength band, the third wavelength band, and the fourth wavelength band, respectively. The obtained light intensity integrated values are RS1, RS2, RS3, and RS4, and the product of the spectral spectra of the continuous spectrum light for each wavelength of the total sensitivity Sum of the S pixels is the first wavelength band, the second wavelength band, and the first. When the light quantity integrated values obtained by integrating in the three wavelength bands and the fourth wavelength band are set to XS1, XS2, XS3, and XS4, the V light, the V light, so as to satisfy the following equation (5). A method for operating an endoscopic system, which comprises a step of calculating a light amount ratio Cv: Cb: Cg: Cr of the B light, the G light, and the R light.

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