JP2016055052A - Endoscope system, light source device, operation method for endoscope system, and operation method for light source device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an endoscope system, a light source device, an operation method for the endoscope system, and an operation method for the light source device capable of guaranteeing the maximum quantity of illumination light even if the light emission quantity of the light source is limited by the radiation performance of the radiation mechanism or the power capacity of the power source.SOLUTION: The endoscope system 10 comprises: a first emission unit for emitting green narrow-band light Gn; a second emission unit for emitting blue narrow-band light Bn; a light source control unit 25 for controlling the first emission unit and second emission unit to apply the first light, second light, or both the first light and second light onto an observation object; and an imaging sensor 48 for imaging return light from the observation object. The light source control unit 25 provides for a first light irradiation period during which the first light is applied onto the observation object, a second light irradiation period during which the second light is applied onto the observation object, and a superposition irradiation period during which both the first light and second light are applied onto the observation object by a different light quantity ratio from the light quantity ratio between the first light during the first light irradiation period and the second light during the second irradiation period.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an endoscope system, a light source device, an operation method of an endoscope system, and an operation method of a light source device that illuminate an observation target with illumination lights of different colors having different wavelength bands.

  In the medical field, diagnosis using an endoscope system including a light source device, an endoscope, and a processor device is widely performed. In medical diagnosis using an endoscope system, an insertion portion of an endoscope is inserted into a subject, and illumination light generated by a light source device is irradiated from the distal end portion to an observation target. Then, using an imaging sensor mounted on the distal end of the endoscope, the observation object is imaged by the return light of the illumination light, and an image of the observation object is generated by processing the obtained imaging signal by the processor device, Display on the monitor. The doctor observes the image displayed on the monitor and diagnoses the lesion.

  As an endoscope system as described above, illumination light having a specific narrow wavelength band (not only observing the observation object in a substantially natural state by irradiating the observation object with white or pseudo-white illumination light) An apparatus is known that generates and displays an image in which a specific tissue or structure is emphasized by irradiating an observation object with narrowband light (hereinafter referred to as narrowband light) and imaging the observation object with the return light. For example, by using a xenon lamp and a blue LED (Light Emitting Diode), simultaneously irradiating the green narrowband light Gn and the blue narrowband light Bn toward the observation target, and imaging the observation target with these return lights. An endoscope system that generates and displays an image in which blood vessels are emphasized is known (Patent Document 1). Also known is an endoscope system equipped with a plurality of semiconductor light sources, and by adjusting the light emission ratio of each of these semiconductor light sources to change the color tone of the illumination light so that an image that can easily detect a lesion can be obtained. (Patent Document 2).

JP 2012-120572 A JP 2012-010881 A

  Since the light source emits light and generates heat when the light source is turned on, the light source device is provided with a heat dissipation mechanism for radiating heat generated by the light source. It is desirable to use a heat dissipation mechanism having a large capacity so that the light source can continuously emit light with the maximum light emission amount, but the large capacity heat dissipation mechanism has a correspondingly large size. However, since the overall size of the light source device and the installation space of the heat dissipation mechanism in the light source device are limited, it is necessary to emit light with a light emission amount lower than the maximum light emission amount if sufficient heat dissipation is to be performed. In this case, for example, if blood vessel enhancement observation is performed using a plurality of light sources as in Patent Documents 1 and 2, it is difficult to obtain the degree of enhancement of the blood vessels and the like requested by the user and the brightness of the entire image. Become.

  In addition, the light source device preferably uses a power source having a power capacity capable of continuously turning on the mounted light source with the maximum light emission amount. However, the power source device has a sufficient power capacity depending on the installation space and the amount of heat generation. There is a case where a power source having the above cannot be used. In this case, since the light amount of the light source is also limited according to the power capacity of the power source, as in the case of the heat dissipation mechanism described above, if blood vessel enhancement observation is performed using a plurality of light sources, enhancement of blood vessels and the like requested by the user is performed. It is difficult to obtain the degree and brightness of the entire image.

  Even when the light emission amount of the light source is limited by the heat dissipation performance of the heat dissipation mechanism or the power capacity of the power source, the present invention can maximize the amount of illumination light within the limit range (light reception by the image sensor). An endoscope system, a light source device, an operation method of the endoscope system, and an operation method of the light source device, in which a blood vessel or the like is emphasized and a bright image is easily obtained stably. With the goal.

  An endoscope system of the present invention includes a first light emitting unit that emits first light, a second light emitting unit that emits second light having a wavelength band different from that of the first light, a first light emitting unit, and a second light emitting unit. A light source control unit that irradiates the observation target with the first light, the second light, or both the first light and the second light, and the first light, the second light, or the first light. An imaging sensor that images return light from the observation target irradiated with both of the second light. The light source control unit includes a first light irradiation period for irradiating the observation object with the first light, a second light irradiation period for irradiating the observation object with the second light, and the first light and the first light irradiation period. The light source control is performed by providing a superimposed irradiation period in which the observation target is irradiated with both the first light and the second light with a light amount ratio different from the light amount ratio of the second light in the two-light irradiation period.

  The light source control unit changes the light amount of the first light in the superimposed irradiation period with respect to the light amount of the first light in the first light irradiation period, or superimposes the light amount of the second light in the second light irradiation period. It is preferable to change the amount of the second light in the period.

  It is preferable that the light source controller reduces or increases one light amount of the first light or the second light in the superimposed irradiation period with time and maintains the other light amount at a constant light amount.

  The light source control unit reduces the light amount of one light having a shorter wavelength band with time in the first light or the second light in the superimposed irradiation period, and reduces the light amount of the other light having a long wavelength band over time. Increasing with increasing is preferable.

  The light source control unit preferably reduces or increases the first light or the second light in the superimposed irradiation period in a stepwise manner.

  An imaging control unit that reads out the signal charge accumulated by the return light of the first light during the second light irradiation period and reads out the signal charge accumulated by the return light of the second light during the first light irradiation period It is preferable to provide.

  The image sensor has a first pixel that receives the first light and a second pixel that receives the second light in a specific number ratio, and the light source control unit is configured to extend the length of the first light irradiation period and the second light irradiation period. The ratio is preferably set to a ratio that correlates with the specific number ratio.

  The readout of the signal charge accumulated by the return light of the first light and the readout of the signal charge accumulated by the return light of the second light are performed during the first light irradiation period, the second light irradiation period, and the superimposed irradiation period. It is preferable to provide an imaging control unit to be performed after completion.

  The light source device of the present invention includes a first light emitting unit that emits first light, a second light emitting unit that emits second light having a wavelength band different from that of the first light, and a first light emitting unit and a second light emitting unit. And a light source controller that controls and irradiates the observation object with the first light, the second light, or both the first light and the second light. The light source control unit includes a first light irradiation period for irradiating the observation object with the first light, a second light irradiation period for irradiating the observation object with the second light, and the first light and the first light irradiation period. The light source control is performed by providing a superimposed irradiation period in which the observation target is irradiated with both the first light and the second light with a light amount ratio different from the light amount ratio of the second light in the two-light irradiation period.

  The operation method of the endoscope system according to the present invention includes a first light emitting unit that emits first light, a second light emitting unit that emits second light having a wavelength band different from that of the first light, a first light emitting unit, and a first light emitting unit. A light source control unit that controls the two light emitting units to irradiate the observation target with the first light, the second light, or both the first light and the second light, and the first light, the second light, or the first light. An operation method of an endoscope system comprising: an imaging sensor that images return light from an observation target irradiated with both one light and second light, and the light source controller irradiates the observation target with the first light. A step of providing a first light irradiation period, a step of providing a second light irradiation period for the light source control unit to irradiate the observation object with the second light, and a light source control unit including the first light of the first light irradiation period Overlapping irradiation period in which the observation object is irradiated with both the first light and the second light at a light amount ratio different from the light amount ratio of the second light in the second light irradiation period. And a step of providing a.

  The operating method of the light source device of the present invention includes a first light emitting unit that emits first light, a second light emitting unit that emits second light having a wavelength band different from that of the first light, a first light emitting unit, and a second light emitting unit. And a light source control unit that irradiates the observation target with at least one of the first light and the second light, and the light source control unit applies the first light to the observation target. Providing a first light irradiation period for irradiating the light source, a step for providing a second light irradiation period for the light source control unit to irradiate the observation object with the second light, and a light source control unit for the first light irradiation period. Providing a superimposed irradiation period in which the observation target is irradiated with both the first light and the second light at a light amount ratio different from the light amount ratio of the light and the second light in the second light irradiation period.

  An endoscope system, a light source device, an operation method of an endoscope system, and an operation method of a light source device according to the present invention include a light source that emits first light and a light source that emits second light having a wavelength band different from that of the first light. Are used to obtain an image in which the structure of a blood vessel or the like included in the observation target is emphasized, and a second light irradiation period for irradiating the observation target with the first light and a second light for irradiating the observation target with the second light. In addition to the light irradiation period, a superimposition irradiation period for irradiating the observation target with the first light and the second light is provided, and the light quantity ratio between the first light and the second light in the superimposition irradiation period is equal to that of the first light irradiation period. The light amount ratio is different from the light amount ratio between the first light and the second light during the second light irradiation period. As a result, even if the light quantity of the first light and the second light is limited by the heat dissipation performance of the heat dissipation mechanism and the power capacity of the power source, the maximum possible light quantity of illumination light is ensured within the limits. The blood vessels and the like are emphasized, and a bright image is easily acquired stably.

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 spectrum of white light WL and blue narrow-band light Bn. It is a graph which shows the spectral characteristic of a band pass filter. It is a graph which shows the spectral characteristic of a dichroic member. It is a graph which shows the spectral characteristic of a color filter. It is explanatory drawing which shows the arrangement | sequence of the pixel of an imaging sensor, and a color filter. It is a flowchart of normal observation mode. 6 is a timing chart of illumination light and an image sensor in a normal observation mode. It is a flowchart of special observation mode. It is a timing chart of the illumination light and imaging sensor at the time of special observation mode. It is a timing chart of a modification. It is a timing chart of a modification. It is a timing chart of a modification. It is a timing chart of a modification. It is the schematic of a capsule endoscope. It is a graph which shows the spectrum of blue narrow-band light and green narrow-band light.

  As shown in FIG. 1, the endoscope system 10 includes an endoscope 12, a light source device 14, a processor device 16, a monitor 18, and a console 19. The endoscope 12 is optically connected to the light source device 14 and electrically connected to the processor device 16. The endoscope 12 includes an insertion portion 12a to be inserted into a subject, an operation portion 12b provided at a proximal end portion of the insertion portion 12a, a bending portion 12c and a distal end portion provided at the distal end side of the insertion portion 12a. 12d. By operating the angle knob 12e of the operation unit 12b, the bending unit 12c performs a bending operation. By this bending operation, the distal end portion 12d is directed in a desired direction.

  In addition to the angle knob 12e, the operation unit 12b is provided with a mode switch (hereinafter referred to as mode switch SW) 13a and a zoom operation unit 13b. The mode switching SW 13a is used for an observation mode switching operation. The endoscope system 10 has a normal observation mode and a special observation mode as observation modes. In the normal observation mode, a natural color image (hereinafter referred to as a normal image) is displayed on the monitor 18 using an image signal obtained by irradiating the observation target with white light and imaging the observation target with the return light. . In the special observation mode, a blood vessel included in an observation object is obtained using an image signal obtained by irradiating the observation object with blue narrow-band light Bn and green narrow-band light Gn and imaging the observation object with these return lights. An image in which a specific structure such as a pit pattern is emphasized (hereinafter referred to as a special image) is displayed on the monitor 18.

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

As shown in FIG. 2, the light source device 14 includes a first light source 21 and a second light source 22 as light sources that can be controlled independently of each other. The first light source 21 is, for example, an LED that emits narrow band light having a center wavelength of 445 ± 10 nm. A phosphor 23 is provided on the light emitting surface of the first light source 21. As shown in FIG. 3, the phosphor 23 absorbs a part of narrow-band blue-violet light (hereinafter referred to as excitation light _BEX ) emitted from the first light source 21 and mainly has a fluorescence wavelength band from green to red. Issue FL. Therefore, when the first light source 21 is turned on, white light WL formed by the excitation light B _EX transmitted through the phosphor 23 and the fluorescence FL emitted from the phosphor 23 is generated. The phosphor 23 is arbitrary as long as it absorbs a part of the excitation light B _EX and generates a fluorescence FL mainly having a wavelength band from green to red, but a plurality of types of phosphors (for example, YAG system) It is preferable to use a phosphor or a material including a phosphor such as BAM (BaMgAl ₁₀ O ₁₇ ).

  A band pass filter (BPF) 24 is detachably provided in the optical path of white light WL generated by turning on the first light source 21. As shown in FIG. 4, the BPF 24 is a band limiting member that has a characteristic of transmitting a wavelength band of 530 nm to 550 nm and cutting light in other wavelength bands. Therefore, when the BPF 24 is inserted into the optical path of the white light WL, green light having a narrow wavelength band of 530 nm to 550 nm (hereinafter, referred to as green narrow band light Gn) is generated from the white light WL. The BPF 24 is inserted into the optical path of the white light WL in the special observation mode, and is retracted from the optical path of the white light WL in the normal observation mode. Therefore, green narrowband light Gn (first light (or second light)) is used as illumination light in the special observation mode, and white light WL is used as illumination light in the normal observation mode. The first light source 21, the phosphor 23, and the BPF 24 constitute a first light emitting unit (or second light emitting unit) that generates the green narrow band light Gn.

  The second light source 22 is an LED that emits light having a narrow wavelength band of 405 ± 10 nm, for example. Unlike the first light source 21, since the phosphor is not provided on the light emitting surface of the second light source 22, the narrow band light emitted from the second light source 22 is used as illumination light as it is. In addition, since the return light of the narrow band light emitted from the second light source 22 is received by the blue pixel of the imaging sensor, the narrow band light emitted from the second light source 22 is hereinafter referred to as blue narrow band light Bn (second light (or First light)). Accordingly, the second light source 22 is a second light emitting unit (or first light emitting unit) that emits the blue narrow band light Bn.

  The timing of turning on (or turning off) the first light source 21 and the second light source 22, the light emission amount at the time of lighting, the light emission time, and the like are controlled by the light source control unit 25 inputting independent control pulses. The first light source 21 and the second light source 22 are turned on when a control pulse is input, and are turned off during a period when the control pulse is not input. In addition, the light source control unit 25 adjusts the pulse intensity (drive voltage or drive current), pulse width, or pulse number of the control pulse input to the first light source 21 or the second light source 22, thereby adjusting the first light source 21. The light emission amount and the light emission time of the second light source 22 are controlled. The light source control unit 25 also performs position control of the BPF 24 according to the set observation mode by using the BPF control mechanism 26.

  More specifically, in the normal observation mode, the light source control unit 25 turns on the first light source 21 and turns off the second light source 22, thereby generating white light WL by the first light source 21 and the phosphor 23. In addition, the BPF 24 is retracted from the optical path of the white light WL. Thus, in the normal observation mode, the white light WL is used as illumination light that illuminates the observation target.

  On the other hand, the light source control unit 25 always inserts the BPF 24 in the optical path of the white light WL in the special observation mode. Then, the light source control unit 25 includes a green narrow band light irradiation period (first light irradiation period (or second light irradiation period)) and a blue narrow band light irradiation period (second light irradiation period (or first light irradiation period). In addition to)), light source control is performed by providing a superimposed irradiation period. During the green narrow-band light irradiation period, the first light source 21 is turned on and the second light source 22 is turned off to irradiate the observation target with the green narrow-band light Gn. During the blue narrow band light irradiation period, the first light source 21 is turned off and the second light source 22 is turned on to irradiate the observation target with the blue narrow band light Bn. During the superimposed irradiation period, both the first light source 21 and the second light source 22 are turned on, and both the green narrow band light Gn and the blue narrow band light Bn (first light and second light (or second light and first light)). Is irradiated to the observation target. The light source control unit 25 maximizes the total amount of light applied to the observation target of each light by performing light source control that provides a green narrow band light irradiation period, a blue narrow band light irradiation period, and a superimposed irradiation period.

Further, the light source control unit 25 determines that the light quantity ratio between the green narrowband light Gn and the blue narrowband light Bn in the superimposed irradiation period is the blue narrowband light Gn in the green narrowband light irradiation period and the blue narrowband light in the blue narrowband light irradiation period. The light emission amounts of the first light source 21 and the second light source 22 are controlled so that the light amount ratio is different from the light amount ratio of the band light Bn. The light amount in each irradiation period is, for example, an average value of instantaneous light amounts during each irradiation period. That is, the average light amount of the green narrow band light Gn during the green narrow band light irradiation period is A _G , the average light amount of the blue narrow band light Bn during the blue narrow band light irradiation period is B _B , and the green narrow band during the superimposed irradiation period If the average amount of light Gn _{C G,} the average amount of the blue narrowband light Bn in superimposed irradiation period and _{C B,} the light source control unit _25, made different from the B B / _{a G} and _C B / _{C G} This suppresses the amount of heat generated during the superimposed irradiation period. As described above, in this embodiment, the average light amount during each irradiation period is used as the light amount during each irradiation period. Instead of averaging, statistical values such as intermediate values, median values, variances, and standard deviations are used for each irradiation period. The amount of light inside may be used.

  When the first light source 21 and the second light source 22 are turned on, the first light source 21, the phosphor 23, and the second light source 22 generate heat. For this reason, the light source device 14 includes a heat dissipation mechanism 27 for radiating heat generated when the first light source 21 and the second light source 22 are turned on. The heat dissipation mechanism 27 is configured by, for example, a heat sink or a cooling fan. The heat dissipation mechanism 27 can completely dissipate heat when each of the first light source 21 and the second light source 22 emits light alone. On the other hand, when the first light source 21 and the second light source 22 emit light simultaneously and continuously, it is possible to completely dissipate heat as long as the light emission amount is lower than the maximum light emission amount. However, even when the first light source 21 and the second light source 22 emit light simultaneously, it is possible to completely dissipate heat as long as the heat is generated when light is emitted instantaneously with the maximum light emission amount. Therefore, even if both the first light source 21 and the second light source 22 are turned on at the maximum light amount when the first light source 21 and the second light source 22 are switched on and off, and the light emission amount is switched, the light source device 14 is stable. Can be operated. Further, in the special observation mode, by providing the overlap irradiation period, the total irradiation light amount to the observation target of the green narrow band light Gn and the blue narrow band light Bn is obtained, but the green narrow band light Gn and the blue narrow band in the overlap irradiation period are obtained. Since the light amount ratio of the band light Bn is controlled to be different from the light amount ratio between the green light narrow band light Gn in the green narrow band light irradiation period and the blue narrow band light Bn in the blue narrow band light irradiation period, Heat generation during the superimposed irradiation period is suppressed by the heat dissipation mechanism 27 within a range permitted by the heat dissipation performance.

  The light source device 14 includes a power source 28 that supplies power to each part of the light source device 14 such as the first light source 21 and the second light source 22. In the present embodiment, the power source 28 has a power capacity capable of lighting the first light source 21 and the second light source 22 simultaneously and continuously with the maximum light amount. For this reason, the light emission amounts of the first light source 21 and the second light source 22 are not limited by the power capacity of the power source 28.

  In addition to the above, the light source device 14 includes an optical path coupling member such as a reflecting member 29a or a dichroic member 29b. The reflecting member 29a is a mirror or a prism that is disposed in the optical path of the blue narrow band light Bn emitted from the second light source 22, reflects at least the blue narrow band light Bn, and guides it to the dichroic member 29b.

  As shown in FIG. 5, the dichroic member 29b is a mirror or a prism having characteristics of transmitting the white light WL and reflecting the blue narrow band light Bn, and the green narrow band light Gn (BPF 24 transmitted from the BPF 24 is retracted). In the optical path of white light WL). In the normal observation mode, since the first light source 21 is turned on and the BPF 24 is retracted, white light WL is incident on the dichroic member 29b. The dichroic member 29 b transmits almost all of the incident white light WL and guides it to the light guide 41. On the other hand, in the special observation mode, the blue narrow band light Bn and the green narrow band light Gn are incident on the dichroic member 29b according to the lighting timing of the first light source 21 and the second light source 22. Since the dichroic member 29b transmits the green narrowband light Gn and reflects the blue narrowband light Bn, at least one of the green narrowband light Gn and the blue narrowband light Bn exits the dichroic member 29b. The emitted green narrow band light Gn and blue narrow band light Bn enter the light guide 41. In addition, a lens or the like (not shown) is provided between the dichroic member 29b and the light guide 41 so as to make each light incident on the light guide 41 efficiently.

  The light guide 41 is built in the endoscope 12 and the universal cord (the cord connecting the endoscope 12, the light source device 14, and the processor device 16), and is guided from an optical path coupling member such as the dichroic member 29b. Is transmitted to the distal end portion 12d of the endoscope 12. A multimode fiber can be used as the light guide 41. As an example, a thin 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.

  As shown in FIG. 2, the distal end portion 12d of the endoscope 12 is provided with an illumination optical system 30a and an imaging optical system 30b. The illumination optical system 30 a has an illumination lens 45, and the illumination light propagated by the light guide 41 is irradiated to the observation object via the illumination lens 45. Therefore, the illumination optical system 30a (or the illumination lens 45) includes the white light WL, the green narrowband light Gn, the blue narrowband light Bn, or both the green narrowband light Gn and the blue narrowband light Bn (green narrowband light). An irradiating unit that irradiates an observation target with illumination light (mixed light of Gn and blue narrowband light Bn) is configured. The imaging optical system 30 b includes an objective lens 46, a zoom lens 47, and an imaging sensor 48. Return light from the observation target enters the image sensor 48 through the objective lens 46 and the zoom lens 47. As a result, an image to be observed is formed on the image sensor 48. The zoom lens 47 is freely moved between the tele end and the wide end by operating the zoom operation unit 13b, and enlarges or reduces the image of the observation target formed on the image sensor 48.

  The imaging sensor 48 images the return light from the observation target irradiated with various illumination lights. That is, the observation target is imaged by accumulating signal charges corresponding to the amount of return light for each pixel. The return light is reflected light or scattered light of illumination light, or fluorescence generated by illumination light. The image sensor 48 is a color image sensor, and three color filters of R (red) color filter, G (green) color filter, and B (blue) color filter shown in FIG. 6 are provided for each pixel. An observation target is imaged and an image signal for each color is output. As shown in FIG. 7, the pixel array of the image sensor 48 is, for example, a Bayer array, and the number ratio of blue pixels (B pixels), green pixels (G pixels), and red pixels (R pixels) is B: G. : R = 1: 2: 1. The blue narrow band light Bn is received by the B pixel (second pixel (or first pixel)), and the green narrow band light Gn is received by the G pixel (first pixel (or second pixel)). 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 accumulates a signal charge for each arbitrary pixel (or for each color pixel), a read operation for reading a signal corresponding to the total amount of the accumulated signal charge, and a signal charge. It is a CMOS image sensor capable of executing each operation of the reset operation to be discarded.

  The imaging control unit 49 controls the timing at which the imaging sensor 48 performs the above operations, the length of the accumulation time, the length of the operation cycle, and the like. More specifically, in the normal observation mode, the imaging control unit 49 accumulates signal charges in all pixels during the irradiation period of the white light WL, and reads the accumulated signal charges at the end of the irradiation period of the white light WL. Let it come out. After the signal charge is read, all pixels are reset during the next white light WL irradiation period.

  On the other hand, in the special observation mode, the imaging control unit 49 causes the G pixel to perform an accumulation operation between the green narrowband light irradiation period and the superimposition irradiation period, and between the blue narrowband light irradiation period and the superimposition irradiation period, B Cause the pixel to perform an accumulation operation. Then, the signal charge accumulated by the return light of the green narrow band light Gn is read out during the blue narrow band light irradiation period, and the signal charge accumulated by the return light of the blue narrow band light Bn is read during the green narrow band light irradiation period. Read. The reset operation is performed after the reading of the pixels of each color is completed and before the next accumulation operation.

  In place of the image sensor 48 which is a primary color image sensor, a complementary color image sensor having complementary color filters of C (cyan), M (magenta), Y (yellow) and G (green) may be used. When the complementary color image sensor is used, CMYG four-color image signals are output. By converting the CMYG four-color image signals into RGB three-color image signals by complementary color-primary color conversion, An RGB image signal similar to that of the image sensor 48 can be obtained.

  Each color image signal output from the image sensor 48 is 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 that 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 52. The digital image signal after A / D conversion is input to the processor device 16.

  The processor device 16 includes an image signal acquisition unit 53, a DSP (Digital Signal Processor) 56, a noise removal unit 58, an image processing switching unit 60, a normal image processing unit 62, a special image processing unit 63, and a video signal. A generation unit 66 and a processor control unit 68 are provided. The image signal acquisition unit 53 acquires 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 demosaicing 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 process, the dark current component is removed from the RGB image signal subjected to the defect correction process, 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 process is subjected to a linear matrix process for improving color reproducibility. After that, brightness and saturation are adjusted by gamma conversion processing. The RGB image signal after the linear matrix processing is subjected to demosaic processing (also referred to as isotropic processing or synchronization processing), and a signal of insufficient color at each pixel is generated by interpolation. By this demosaic processing, all the pixels have RGB signals.

  The noise removal unit 58 removes noise from the RGB image signal by performing noise removal processing (for example, using a moving average method or a median filter method) on the RGB image signal that has been demosaiced by the DSP 56. The RGB image signal from which noise has been removed is transmitted to the image processing switching unit 60. The image processing switching unit 60 transmits the RGB image signal to the normal image processing unit 62 when the mode switching SW 13a is set to the normal observation mode, and the RGB image signal when the mode is set to the special observation mode. The signal is transmitted to the special image processing unit 63.

  The normal image processing unit 62 operates when the normal observation mode is set, and performs color conversion processing, color enhancement processing, and structure enhancement processing on the RGB image signal to generate a normal image. In the color conversion processing, color conversion processing is performed on the RGB image signal by 3 × 3 matrix processing, gradation conversion processing, three-dimensional LUT (Look Up Table) processing, and the like. The color enhancement process is performed on the RGB image signal that has been subjected to the color conversion process. The structure enhancement process is a process for enhancing the structure of the observation target such as a surface blood vessel or a pit pattern, and is performed on the RGB image signal after the color enhancement process. As described above, a color image using an RGB image signal subjected to various image processing and the like up to the structure enhancement processing for each channel corresponding to RGB is a normal image.

  The special image processing unit 63 operates when the special observation mode is set, and performs a color conversion process, a color enhancement process, and a structure enhancement process on the RGB image signal to generate a special image. The color conversion process, the color enhancement process, and the structure enhancement process performed by the special image processing unit 63 are processes similar to those performed by the normal image processing unit 62, although the parameters are different. The special image generated by the special image processing unit 63 is a color image in which the B image signal is assigned to the B channel and the G channel, and the G image signal is assigned to the R channel. Is emphasized.

  The normal image generated by the normal image processing unit 62 and the special image generated by the special image processing unit 63 are input to the video signal generation unit 66. The video signal generator 66 converts a normal image or a special image 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 a normal image or a special image.

  The processor control unit 68 comprehensively controls each unit of the processor device 16. For example, the processor control unit 68 acquires a switching signal from the mode switching SW 13a, and the image processing switching unit 60 switches the image processing unit that transmits the image signal according to the selected observation mode. Further, the processor control unit 68 inputs the control signal to the light source control unit 25 of the light source device 14 and the imaging control unit 49 of the endoscope 12, so that the operation content and timing of the light source device 14 and the endoscope 12 are determined. Control. For example, the processor control unit 68 changes the operation method of the light source control unit 25 and the imaging sensor 48 according to the selected observation mode.

  In addition, the processor control unit 68 generates an image signal acquired by the image signal acquisition unit 53, an image signal input to the image processing switching unit 60, a normal image generated by the normal image processing unit 62, or a special image processing unit 63. A brightness detection unit (not shown) that detects the brightness of the normal image or the special image using any of the special images is provided. The processor control unit 68 controls the amount of illumination light generated by the light source device 14 or the length of the accumulation time of the image sensor 48 based on the brightness of the normal image or special image detected by the brightness detection unit.

Next, a series of flows in this embodiment will be described. First, when the observation mode is set to the normal observation mode by the operation of the mode switching SW 13a, the endoscope system 10 operates according to the flowchart shown in FIG. 8 and the timing chart shown in FIG. When the observation mode is the normal observation mode, the light source control unit 25 retracts the BPF 24 from the optical path of the white light WL. Then, the first light source 21 is turned on at the maximum light emission amount and the second light source 22 is turned off within the range permitted by the heat dissipation performance of the heat dissipation mechanism 27 (S11), thereby irradiating the observation target with the white light WL. Thereby, the light source control unit 25 irradiates the observation target with the maximum light amount L _WL (MAX) as the light amount L _WL of the white light WL. Further, the light source control unit 25 adjusts the length of the irradiation period of the white light WL based on a control signal from the processor control unit 68. As a result, the period (accumulation period) in which the imaging sensor 48 performs the accumulation operation and the irradiation period of the white light WL in the illumination light irradiation and imaging period Ts coincide with each other. The light source control unit 25 stops the irradiation of the white light WL by turning off the first light source 21 during the period during which the reading operation is performed (reading period) and during the reset operation.

  In addition, the imaging control unit 49 controls the operation timing of various operations of the imaging sensor 48 based on the control signal from the processor control unit 68, so that the observation target is set for each period Ts according to the irradiation timing of the white light WL. Take an image. Specifically, the imaging control unit 49 causes the imaging sensor 48 to perform an accumulation operation during the white light WL irradiation period (S12), and causes a reading operation and a reset operation to be performed during the white light WL extinguishing period (S13). Accumulation, readout, and reset in the normal observation mode are performed in common for all pixels without distinction of colors.

  Irradiation and imaging of the white light WL at the period Ts are repeated until the observation mode is switched to the special observation mode (S14). The processor device 16 generates a normal image for each cycle Ts using an image signal output by the imaging sensor 48 by imaging in one cycle Ts. The normal image is displayed on the monitor 18 in real time.

Next, when the observation mode is set to the special observation mode by the operation of the mode switching SW 13a, the endoscope system 10 operates according to the flowchart shown in FIG. 10 and the timing chart shown in FIG. When the observation mode is the special observation mode, the light source control unit 25 inserts the BPF 24 into the optical path of the white light WL. Thereafter, the first light source 21 is turned off and the second light source 22 is turned on to provide a blue narrow band light irradiation period P _B for irradiating the observation target with the blue narrow band light Bn as illumination light (S21: first) 2 light irradiation step (or first light irradiation step)).

In the blue narrow band light irradiation period P _B , the light source control unit 25 turns on the second light source 22 while maintaining a constant light amount. For this reason, the light quantity L _Bn of the blue narrow band light Bn irradiated to the observation target during the blue narrow band light period P _B is a constant light quantity B _B (average light quantity B _B ). The imaging control unit 49, between the blue narrow-band light illumination period P _B, the B pixel of the image sensor 48 to perform the accumulation of the signal charges by the return light of the blue narrow-band light Bn during irradiation (S22), The G pixel is caused to read out the signal charge accumulated by the return light of the green narrowband light Gn in the immediately preceding cycle Ts.

Next, the light source control unit 25 turns on the first light source 21 and turns on the second light source 22 to irradiate the observation target with the mixed light of the blue narrow band light Bn and the green narrow band light Gn. providing a period _{P M} (S23: duplication irradiation step).

In the superimposed irradiation period P _M, the light source control unit 25 decreases with the amount of light emission time of the second light source 22 (tapering) is, to zero at the end of the superimposed overlap period P _M. For this reason, the light quantity L _Bn of the blue narrow band light _Bn gradually decreases from the light quantity B _B of the blue narrow band light irradiation period P _B to zero. The average amount during this period of the blue narrow-band light Bn is C _B. Moreover, the superimposed irradiation period P _M, the light source control unit 25, turning it on the first light source 21 to maintain a constant amount of light. Therefore, the light amount _{L Gn} of the green narrowband light Gn of superimposed irradiation period _{P M} is a constant amount _{A G} (average amount _{A G).} The imaging control unit 49, between the superimposed irradiation period P _M, the B pixel of the image sensor 48, to perform the signal charge accumulation due to return light blue narrow-band light Bn during irradiation, and the G pixel Causes signal charges to be accumulated by the return light of the green narrow band light Gn (S24).

Thereafter, the light source control unit 25, the first light source 21 illuminates and, by turning off the second light source 22 is provided with a green narrow-band light illumination period P _G for irradiating the observation target green narrowband light Gn ( S25: First light irradiation step (or second light irradiation step)).

In the green narrow-band light illumination period P _G, the light source control unit 25, continuously from the superimposed irradiation period P _M, and lights up the first light source 21 to maintain a constant amount of light. Therefore, the light amount L _Gn of the green narrowband light Gn irradiated on the observation target during the green narrow-band light illumination period P _G is a constant amount of light A _{G (average} amount A _G). In addition, the imaging control unit 49 causes the B pixel that has completed accumulation for one cycle Ts to read out the signal charge (S26), and the G pixel performs accumulation operation using the return light of the green narrowband light Gn that is being irradiated. Is continued (S27).

  The operation for one cycle Ts in the special observation mode is repeated until the observation mode is switched to the normal observation mode (S28). The reset operation is performed for each B pixel or G pixel after the read operation is completed and before the next accumulation operation is started. The processor device 16 generates a special image every cycle Ts using an image signal output by the imaging sensor 48 by imaging in one cycle Ts. The special image is displayed on the monitor 18 in real time.

As described above, in the endoscope system 10, in the period Ts of the illumination and imaging of the illumination light, the green narrow-band light illumination period P _G irradiating the green narrow-band light Gn the observation target, blue observation target in addition to the blue narrow-band light P _B which irradiates narrowband light Bn, by providing a superimposed irradiation period P _M of irradiating the observation target mixed light of the green narrow-band light Gn and blue narrow band light Bn, green narrowband The total amount of light irradiated within one cycle Ts on the observation target of the light Gn and the blue narrow-band light Bn is earned. Then, to the green narrowband light Gn and amount ratio of the blue narrow-band light Bn of superimposed irradiation period _{P M (C B / A G} ) are green narrowband light Gn and blue narrow band of green narrowband light irradiation period P _G The light emission amounts of the first light source 21 and the second light source 22 are controlled so as to have different values with respect to the light amount ratio (B _B / A _G ) with the blue narrow-band light Bn in the light irradiation period P _B. Therefore, even if there is limit to the amount of light emission of the first light source 21 and the second light source 22 by the radiation mechanism 27, the amount of heat generated in the superimposed irradiation period P _M, within the scope allowed by the heat radiation performance of the heat radiation mechanism 27 Can be suppressed.

  That is, in the endoscope system 10, even when the light emission amount of the first light source 21 or the second light source 22 is limited by the heat dissipation performance of the heat dissipation mechanism 27, the heat generation amount is within the range allowed by the heat dissipation performance of the heat dissipation mechanism 27. Since the total amount of light emitted from each of the green narrow band light Gn and the blue narrow band light Bn can be maximized while suppressing blood pressure, blood vessels and the like are emphasized, and a bright special image is easily acquired stably. ing.

The light source control unit 25 determines the ratio of the length of the blue narrow band light irradiation period P _B for reading out the G pixel and the length of the green narrow band light irradiation period P _G for reading out the B pixel of the image sensor 48. It is preferable to set a ratio that correlates with the number ratio (specific number ratio) in the pixel array. In the case of this embodiment, the pixel array of the image sensor 48 is a Bayer array, and the number ratio of G pixels to B pixels is G: B = 2: 1. : B pixel = 2: 1. Therefore, the light source control unit 25 sets the ratio of the length of the blue narrow band light irradiation period P _B for reading the G pixel and the green narrow band light irradiation period P _G for reading the B pixel to 2: 1. It is preferable to do.

In the above embodiment, the light amount of the blue narrow band light Bn is gradually decreased and the light amount of the green narrow band light Gn is maintained at a constant light amount in the superimposed irradiation period PM. As shown, the light amount of the blue narrow band light Bn may be maintained at a constant light amount, and the light amount of the green narrow band light Gn may be increased (gradually increased) with time. In this case, the light amount of the blue narrowband light Bn of superimposed irradiation period P _M (average amount) is constant at B _B, the light amount (average amount) of the green narrowband light Gn of superimposed irradiation period P _M is C _{G (<} A _G ). Therefore, the light quantity ratio B _{B /} C _G of the blue narrow-band light Bn and green narrow-band light Gn of superimposed irradiation period PM, the green narrow-band light Gn and blue narrow-band light illumination period of the green narrowband light irradiation period P _G It becomes a different value with respect to the light amount ratio (B _B / A _G ) of the blue narrow band light Bn of P _B. Therefore, as in the above embodiment, the total amount of light emitted from each of the green narrow-band light Gn and the blue narrow-band light Bn is maximized while suppressing the amount of heat generation within a range allowed by the heat dissipation performance of the heat dissipation mechanism 27. be able to.

In addition, absorption by hemoglobin is generally larger as light in a short wavelength band, and the image signal tends to be darker. For this reason, when comparing the green narrowband light Gn and the blue narrowband light Bn, priority is given to securing the light quantity of the blue narrowband light Bn having a shorter wavelength band, and the blue narrowband light as in the above embodiment. while ensuring the irradiation light amount of the blue narrowband light Bn large amount as possible light irradiation period P _B, by superimposing the irradiation light amount of the blue narrowband light Bn while gradually decreasing the amount of light at superimposed irradiation period P _M, It is good to maximize the total amount of irradiation light.

The green narrowband light irradiation period P _G, blue narrow-band light illumination period P _B, the order of the superimposed irradiation period P _M is out of order, as shown in FIG. 13, the green narrow-band light illumination period P _G, blue narrowband light irradiation period P _B, by exchanging the order of superimposing irradiation period P _M, the superimposed irradiation period P _M, is gradually increased the amount of light of the blue narrowband light Bn, by keeping the green narrow-band light Gn constant amount Also good. Similarly, the superimposed irradiation period P _M, keeping the blue narrow-band light Bn constant light amount, and may be gradually decreases the light quantity of the green narrowband light Gn.

Furthermore, in the above embodiment, by decreasing the blue narrow-band light Bn in superimposed irradiation period P _M, amount of the blue narrowband light Bn of superimposed irradiation period P _M is blue narrowband blue narrowband light irradiation period it may be changed stepwise with respect to the light amount B _B light Bn. For example, as shown in FIG. 14, when reducing the amount of the blue narrowband light Bn of superimposed irradiation period P _M in two stages, the constant quantity when varying at the first stage, the average amount of light C _B May be maintained. The green narrowband light irradiation period P _G, superimposed irradiation period P _M, in the case of performing irradiation in the order of blue narrow-band light illumination period P _B (see FIG. 13), the superimposed irradiation period P _M, green narrowband The light quantity of the blue narrow band light Bn may be changed stepwise while the light quantity of the light Gn is kept constant. Incidentally, the light amount of the blue narrowband light Bn of superimposed irradiation period P _M is a modification of FIG. 14, but 2 have phase changes with respect to the light amount B _B of the blue narrow-band light Bn blue narrow-band light irradiation period, amount may be changed in the blue narrow-band light Bn of superimposed irradiation period P _M in a plurality of stages. Needless to say, if the stage of change is made finer, it will approach the example of gradually reducing the blue narrowband light Bn as in the above embodiment.

In the above embodiment and the modifications, the superimposed irradiation period P _M, but by changing either the amount of light of the blue narrowband light Bn or the green narrow-band light Gn, as shown in FIG. 15, superimposed irradiation period in P _M, it may change the light amount of both the blue narrow-band light Bn and green narrow-band light Gn. In this way, easy to suppress particularly the amount of heat generated in the superimposed irradiation period P _M, and likely to earn the total irradiation amount of the blue narrowband light Bn and green narrow-band light Gn. Of course, the same applies to the case where the amount of light is changed stepwise as in the modification of FIG. Further, since the absorption by hemoglobin is generally larger in the light of the short wavelength band, and the image signal tends to be darker, the amount of irradiation of the blue narrow band light Bn is secured with as much light as possible in the blue narrow band light irradiation period P _B. in, it is preferable to maximize the total irradiation light amount plus the irradiation light amount of the blue narrowband light Bn while gradually decreasing the amount of light at superimposed irradiation period P _M. Then, the green narrow-band light Gn having a long wavelength band which tends to ensure a relatively brightness is preferably maximize gradually increasing the amount of light during the superimposed irradiation period P _M and the total irradiation dose.

In the above-described embodiment and modification, a CMOS image sensor is used as the image sensor 48, but a CCD image sensor may be used instead. When a CCD image sensor is used as the image sensor 48, the signal charge accumulated in the immediately preceding cycle Ts can be read out while accumulating the signal charge. Thus, the imaging control unit 49, the readout of the signal charge stored in each color pixel, a green one set narrowband light irradiation period P _G, blue narrow-band light illumination period P _B, and superimposes the completion of the irradiation period P _M Thereafter, it can be performed collectively during the execution of the operation of the next illumination light irradiation and imaging cycle Ts.

  In the embodiment and the modification, the light emission amount of the first light source 21 and the second light source 22 is limited by the heat dissipation performance of the heat dissipation mechanism 27, but the power capacity of the power source 28 allows the first light source 21 and the second light source 22 to The present invention is also suitable when the amount of light emission is limited.

  In the above-described embodiment and modification, the present invention is implemented by the endoscope system 10 that performs observation by inserting the endoscope 12 provided with the imaging sensor 48 into the subject. The present invention is also suitable for a mirror system. For example, as shown in FIG. 16, the capsule endoscope system includes at least a capsule endoscope 300 and a processor device (not shown).

  The capsule endoscope 300 includes a light source 302, a light source control unit 303, an image sensor 304, a signal processing unit 306, and a transmission / reception antenna 308. The light source 302 includes a first light source and a phosphor for generating white light WL, a BPF that generates green narrowband light Gn from the white light WL, and a second light source that generates blue narrowband light Bn. . Further, since the BPF is always arranged on the phosphor, the light source 302 corresponds to a state where the endoscope system 10 of the above embodiment is set to the special observation mode.

  The light source control unit 303 controls driving of the light source 302 in the same manner as the light source control unit 25 of the above embodiment. Further, the light source control unit 303 can communicate with the processor device of the capsule endoscope system wirelessly by the transmission / reception antenna 308. The processor device of the capsule endoscope system is substantially the same as the processor device 16 of the above embodiment, but the signal processing unit 306 having the function of the special image processing unit 63 is provided in the capsule endoscope 300. The special image generated by the signal processing unit 306 is transmitted to the processor device via the transmission / reception antenna 308. The image sensor 304 is configured in the same manner as the image sensor 48 of the above embodiment. The battery 309 is a power source that supplies power to each part of the capsule endoscope 300, and the heat radiating plate 310 corresponds to the heat radiating mechanism 27 of the above embodiment.

  In the capsule endoscope 300, since the heat radiating destination of the heat generated by the light source 302 is in the subject, the light amount is greatly limited by the amount of heat generated. In addition, since the capsule endoscope 300 is driven by the battery 309 having limited electric power, the light emission amount of the light source 302 is easily limited by the electric power held by the battery 309. Therefore, the present invention is particularly suitable for the capsule endoscope 300.

  In the above embodiment and the modification, the green narrowband light Gn of 530 nm to 550 nm and the blue narrowband light Bn of 405 ± 10 nm are used in the special observation mode, but have different wavelength bands. Green narrow band light and blue narrow band light may be used. For example, as shown in FIG. 17, blue narrowband light Bn2 having a center wavelength of 415 ± 10 nm and a wavelength band of approximately 390 nm to 450 nm can be used in place of the blue narrowband light Bn of the above embodiment. . Further, the green narrowband light Gn2 having a wavelength band of approximately 520 nm to 570 nm can be used instead of the green narrowband light Gn of the above embodiment.

DESCRIPTION OF SYMBOLS 10 Endoscope system 12 Endoscope 14 Light source device 16 Processor apparatus 21 1st light source 22 2nd light source 23 Phosphor 24 BPF
25, 303 Light source control unit 28 Power supply 48, 304 Imaging sensor 49 Imaging control unit 62 Normal image processing unit 63 Special image processing unit

Claims (11)

A first light emitting unit for emitting first light;
A second light emitting unit that emits second light having a wavelength band different from that of the first light;
A light source control unit that controls the first light emitting unit and the second light emitting unit to irradiate the observation target with the first light, the second light, or both the first light and the second light; ,
An imaging sensor that captures the first light, the second light, or the return light from the observation target irradiated with both the first light and the second light;
The light source controller is
A first light irradiation period for irradiating the observation object with the first light;
A second light irradiation period for irradiating the observation object with the second light;
The observation object is irradiated with both the first light and the second light at a light amount ratio different from the light amount ratio between the first light in the first light irradiation period and the second light in the second light irradiation period. A superimposed irradiation period to be
Endoscope system that controls the light source by providing.   The light source control unit changes a light amount of the first light in the superimposed irradiation period with respect to a light amount of the first light in the first light irradiation period, or the second light in the second light irradiation period. The endoscope system according to claim 1, wherein the amount of the second light in the superimposed irradiation period is changed with respect to the amount of light.   The internal light source according to claim 2, wherein the light source control unit decreases or increases one light amount of the first light or the second light during the superimposed irradiation period with time, and maintains the other light amount at a constant light amount. Mirror system.   The light source control unit decreases the light amount of one light having a shorter wavelength band with time in the first light or the second light in the superimposed irradiation period, and the other light having a long wavelength band The endoscope system according to claim 2, wherein the amount of light increases with time.   The endoscope system according to any one of claims 2 to 4, wherein the light source control unit reduces or increases the first light or the second light in the superimposed irradiation period in a stepwise manner.   The signal charge accumulated by the return light of the first light is read during the second light irradiation period, and the signal charge accumulated by the return light of the second light is read during the first light irradiation period. The endoscope system of any one of Claims 1-5 provided with the imaging control part to be made. The imaging sensor includes a first pixel that receives the first light and a second pixel that receives the second light in a specific number ratio,
The endoscope system according to claim 6, wherein the light source control unit sets a ratio of the lengths of the first light irradiation period and the second light irradiation period to a ratio that correlates with the specific number ratio.   Reading the signal charge accumulated by the return light of the first light and reading the signal charge accumulated by the return light of the second light are the first light irradiation period, the second light irradiation period, and The endoscope system according to any one of claims 1 to 5, further comprising an imaging control unit that is performed after completion of the superimposed irradiation period. A first light emitting unit for emitting first light;
A second light emitting unit that emits second light having a wavelength band different from that of the first light;
A light source control unit that controls the first light emitting unit and the second light emitting unit to irradiate the observation target with the first light, the second light, or both the first light and the second light; ,
With
The light source controller is
A first light irradiation period for irradiating the observation object with the first light;
A second light irradiation period for irradiating the observation object with the second light;
The observation object is irradiated with both the first light and the second light at a light amount ratio different from the light amount ratio of the first light during the first light irradiation period and the second light during the second light irradiation period. Superimposed irradiation period;
A light source device that performs light source control by providing Controlling a first light emitting unit that emits first light, a second light emitting unit that emits second light having a wavelength band different from that of the first light, and the first light emitting unit and the second light emitting unit, A light source control unit for irradiating the observation object with the first light, the second light, or both the first light and the second light; and the first light, the second light, or the first light. And an imaging sensor that images the return light from the observation target irradiated with both of the second light and the operation method of the endoscope system,
The light source control unit providing a first light irradiation period for irradiating the observation object with the first light;
The light source control unit providing a second light irradiation period for irradiating the observation object with the second light;
The light source control unit emits both the first light and the second light with a light amount ratio different from a light amount ratio of the first light in the first light irradiation period and the second light in the second light irradiation period. Providing a superimposed irradiation period for irradiating the observation object;
A method of operating an endoscope system comprising: Controlling a first light emitting unit that emits first light, a second light emitting unit that emits second light having a wavelength band different from that of the first light, and the first light emitting unit and the second light emitting unit, In a method of operating a light source device comprising: the first light, the second light, or a light source control unit that irradiates an observation target with both the first light and the second light.
The light source control unit providing a first light irradiation period for irradiating the observation object with the first light;
The light source control unit providing a second light irradiation period for irradiating the observation object with the second light;
The light source control unit emits both the first light and the second light with a light amount ratio different from a light amount ratio of the first light in the first light irradiation period and the second light in the second light irradiation period. Providing a superimposed irradiation period for irradiating the observation object;
A method of operating a light source device comprising:

Images