Light source device and endoscope system

Abstract

To reduce unnecessary light radiated onto an object under observation. A light source device (100) has a first light source (110), a second light source (150), a multiplexing unit (130), and a filter (170). The first light source (110) emits light including a first wavelength band. The second light source (150) emits light including a second wavelength band excited by a phosphor. The multiplexing unit (130) multiplexes light from the first light source (110) and light from the second light source (150). The filter (170) is disposed between the multiplexing unit (130) and the second light source (150), transmits light in the second wavelength band, and attenuates light in the first wavelength band.

Description

Light source device and endoscope system

[0001] The present disclosure relates to a light source device and an endoscope system.

[0002] Endoscopes are widely used as devices for observing the internal structures of the human body and the like. Particularly in the medical field, endoscopes have become indispensable with the development of surgical techniques using endoscopes. These endoscopes include a light source for illuminating the affected area and a light guide made of an optical fiber for guiding the light from the light source. Light guides are typically configured with a small diameter because they are inserted into the human body and the like. To efficiently guide light into such light guides, semiconductor lasers with small light-emitting spot sizes and narrow radiation angles are used as light sources. For example, an endoscope has been proposed that uses a semiconductor laser as a light source and a white LED as an auxiliary light source (see, for example, Patent Document 1).

[0003] The color rendering can be improved by using a white LED, which emits light over a relatively wide wavelength range, as an auxiliary light source. This white LED includes a light-emitting element such as a blue LED and a phosphor that emits fluorescence when excited by the light from the light-emitting element. This fluorescence emits light over a relatively wide wavelength range. This fluorescence is mixed with the light from the light-emitting element to generate white light with a wide wavelength range.

[0004] In recent years, endoscopes have been enhanced with the addition of a drug fluorescence observation function, evolving into devices that support physicians' surgical procedures. Drug fluorescence observation involves observing the fluorescence generated when a drug injected into an affected area reacts to specific light (excitation light). To achieve this fluorescence observation, it is necessary to select and image the drug fluorescence from the light emitted from the affected area irradiated with excitation light. Because the excitation light and drug fluorescence have different wavelength bands, the drug fluorescence can be separated using an optical filter. By capturing images using an imaging device equipped with such a filter, it is possible to generate a fluorescence image based on the drug fluorescence.

[0005] However, if there is unwanted light whose wavelength band overlaps with that of the fluorescent agent, noise due to the unwanted light occurs, degrading the quality of the fluorescence image. This is because the unwanted light cannot be sufficiently removed by a filter. To improve the signal-to-noise ratio of a fluorescence observation image, it is necessary to reduce the unwanted light.

[0006] International Publication No. 2020 / 036112

[0007] Because fluorescence observation is an extension of normal observation, a light source device configured for coaxial illumination is required, which can irradiate the white light used in normal observation and the excitation light used in fluorescence observation from the same light source on the same axis. This is because a system that requires separate white light sources and excitation light sources and switching between them reduces convenience. In this coaxial illumination, the white light and excitation light are guided through the same optical fiber. For this reason, the light used for drug excitation may be reflected at the input end of the optical fiber, etc., and may reach the light source device as returned light.

[0008] As described above, a white LED is used as a light source for white light. When the wavelength band of the light source for exciting the phosphor in the white LED is close to the wavelength band of the excitation light for the fluorescent agent, for example, when a fluorescent agent such as fluorescein is used, the phosphor in the white LED is excited by the returned light, generating fluorescence. When this fluorescence is irradiated onto the affected area, it becomes the aforementioned unwanted light. Therefore, conventional endoscopes have the problem of increased unwanted light and reduced quality of the fluorescent image.

[0009] Therefore, the present disclosure proposes a light source device that employs coaxial illumination while reducing unnecessary light, and an endoscope system that uses the light source device.

[0010] The light source device of the present disclosure includes a first light source that emits light including a first wavelength band, a second light source that emits light including a second wavelength band excited by a phosphor, a multiplexing section that multiplexes light from the first light source and light from the second light source, and a filter that is disposed between the multiplexing section and the second light source and transmits light in the second wavelength band and attenuates light in the first wavelength band.

[0011] FIG. 11 is a diagram illustrating an example configuration of an endoscope according to an embodiment of the present disclosure. FIG. 12 is a diagram illustrating an example configuration of a light source device according to a first embodiment of the present disclosure. FIG. 13 is a diagram illustrating an example of emitted light from a second light source according to an embodiment of the present disclosure. FIG. 14 is a diagram illustrating an example of the characteristics of a multiplexing section according to an embodiment of the present disclosure. FIG. 15 is a diagram illustrating an example of the characteristics of a filter according to an embodiment of the present disclosure. FIG. 16 is a diagram illustrating another example of the characteristics of a filter according to an embodiment of the present disclosure. FIG. 17 is a diagram illustrating an example configuration of a light source device according to a second embodiment of the present disclosure. FIG. 18 is a diagram illustrating an example configuration of a light source device according to a third embodiment of the present disclosure. FIG. 19 is a diagram illustrating an example configuration of an imaging device according to an embodiment of the present disclosure. FIG. 19 is a diagram illustrating an example schematic configuration of an endoscopic system. FIG. 10 is a diagram illustrating an example configuration of the endoscope and CCU shown in FIG. 10. FIG. 19 is a diagram illustrating an example schematic configuration of a microsurgical system.

[0012] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. The description will be given in the following order. Note that in the following embodiments, the same components are designated by the same reference numerals, and redundant description will be omitted. 1. First embodiment 2. Second embodiment 3. Third embodiment 4. Configuration of imaging device 5. Application example

[0013] (1. First Embodiment) [Configuration of Endoscope] FIG. 1 is a diagram illustrating an example configuration of an endoscope according to an embodiment of the present disclosure. The figure illustrates an example configuration of an endoscope system 1. The endoscope system 1 in the figure is a device for observing the inside of a living body. The endoscope system 1 in the figure generates an image of an observation target 2 using an imaging device (imaging device 10) while irradiating the observation target 2 with light 3. The endoscope system 1 includes a light source device 100, a light guiding unit 40, the imaging device 10, a signal line 20, and a camera control unit (CCU) 30.

[0014] The light source device 100 generates light to be irradiated onto the observation object 2. The light source device 100 generates white light for observation and excitation light for drug excitation. The light source device 100 transmits the generated white light and excitation light to the observation object 2 via the light guide section 40. The light source device 100 also emits the white light and excitation light. Details of the light source device 100 will be described later.

[0015] The light guiding unit 40 guides the light emitted by the light source device 100. The light guiding unit 40 is configured of an optical fiber. The light guided by the light guiding unit 40 is irradiated onto the observation target 2 from the light emitting unit 41. The light guiding unit 40 is also referred to as a light guide.

[0016] The imaging device 10 generates an image of the observation target 2. The CCU 30 controls the imaging device 10. The imaging device 10 captures an image and generates an image based on the control of the CCU 30. The generated image is transmitted to the CCU 30. The imaging device 10 and the CCU 30 are connected by a signal line 20.

[0017] When observing the observation target 2, the light source device 100 emits white light, and the imaging device 10 captures light from the observation target 2 based on the white light to generate an observation image. When performing fluorescence observation, the light source device 100 emits excitation light, and the imaging device 10 captures agent fluorescence based on the excitation light to generate a fluorescence image. These operations are performed under the control of the CCU 30. The observation image and the fluorescence image are displayed on a monitor or the like. The observation image and the fluorescence image can be switched between and displayed. The fluorescence image can also be superimposed on the observation image.

[0018] 1 is assumed to be a flexible endoscope, but the endoscope system 1 can also be configured as a rigid endoscope.

[0019] 2 is a diagram showing an example of the configuration of a light source device according to the first embodiment of the present disclosure. The figure is a block diagram showing an example of the configuration of the light source device 100. The light source device 100 includes a first light source 110, a second light source 150, a multiplexing unit 130, a condenser lens 140, collimating lenses 120 and 160, and a filter 170.

[0020] The first light source 110 emits light including a first wavelength band. Here, the light in the first wavelength band corresponds to the excitation light described above. For example, blue light can be used as the light in the first wavelength band. The first light source 110 includes a blue laser diode that emits blue light. Note that the drug excited by the light in the first wavelength band emits, for example, yellow fluorescence.

[0021] The second light source 150 emits light, for example, white light, to irradiate the observation target 2. The second light source 150 emits light including a second wavelength band. The second light source 150 includes a light-emitting element 151 and a phosphor 152.

[0022] The light emitting element 151 emits excitation light, which is light in a second wavelength band. The light in the second wavelength band may be, for example, blue light. The light in the second wavelength band is configured to be a wavelength band different from the light in the first wavelength band.

[0023] Furthermore, the phosphor 152 is excited by the excitation light from the light-emitting element 151 and emits fluorescence in a third wavelength band. For example, yellow light can be used as the light in the third wavelength band. In this case, a yellow phosphor can be used as the phosphor 152. The excitation light from the light-emitting element 151 and the fluorescence from the phosphor 152 are mixed to generate white light, which is emitted from the second light source 150. That is, the second light source 150 emits light including light in the second wavelength band and light in the third wavelength band. For convenience, the light emitted from the second light source 150 is referred to as white light, but the wavelength band of the light emitted from the second light source 150 is not limited to white.

[0024] The multiplexing unit 130 multiplexes the light from the first light source 110 and the light from the second light source 150. Specifically, the multiplexing unit 130 combines the light from the first light source 110 and the light from the second light source 150 by integrating the optical path through which the light passes and the optical path through which the light passes. A dichroic mirror, for example, can be applied to the multiplexing unit 130.

[0025] The condenser lens 140 is a lens that condenses light from the multiplexer 130 (light from the first light source 110 and light from the second light source 150). The condenser lens 140 condenses the light from the first light source 110 and the like onto the incident end 42 of the light guiding unit 40. The incident end 42 corresponds to the entrance of the optical fiber that constitutes the light guiding unit 40.

[0026] The parallel light lenses 120 and 160 are lenses that convert diffused light into parallel light. The parallel light lens 120 converts light from the first light source 110 into parallel light. The parallel light lens 160 converts light from the second light source 150 into parallel light. The light converted into parallel light enters the multiplexing unit 130. The parallel light lens 120 is an example of a "first parallel light lens" in the present disclosure. The parallel light lens 160 is an example of a "second parallel light lens" in the present disclosure.

[0027] The filter 170 is disposed between the multiplexing unit 130 and the second light source 150 to transmit light from the second light source 150 and to attenuate light in the first wavelength band. The filter 170 transmits white light from the second light source 150 and blocks light originating from the light emitted by the first light source 110 by attenuating the light. The light originating from the light emitted by the first light source 110 corresponds to the returned light 103 described below. Note that the filter 170 in FIG. 2 represents an example in which the filter 170 is disposed between the multiplexing unit 130 and the collimating lens 160. For example, a dielectric multilayer film filter can be used as the filter 170.

[0028] 2 indicate the paths of light. Light 101 emitted from the first light source 110 is converted into parallel light by the parallel light lens 120, passes through the multiplexing unit 130, is collected by the condenser lens 140, and enters the incident end 42. Light 102 from the second light source 150 is converted into parallel light by the parallel light lens 160, is reflected by the multiplexing unit 130, is collected by the condenser lens 140, and enters the incident end 42.

[0029] As described above, the light source device 100 emits white light and excitation light. In the light source device 100 of FIG. 2 , light is emitted from the first light source 110 and the second light source 150. During fluorescence observation, light 101 from the first light source 110 is incident on the incident end 42 of the light guide unit 40. At this time, a portion of the light from the first light source 110 is reflected at the incident end 42 and emitted toward the multiplexing unit 130. This light is referred to as returned light 103. A portion of this returned light 103 is further reflected at the multiplexing unit 130 and emitted toward the second light source 150. When this returned light 103 reaches the phosphor 152, the phosphor 152 is excited and generates fluorescence. This fluorescence is emitted from the light source device 100 and irradiated onto the observation target 2, becoming unwanted light. This unwanted light has a wavelength band close to that of the agent fluorescence, making it difficult to remove in the imaging device 10.

[0030] Therefore, the filter 170 is disposed to attenuate the return light 103 and prevent the return light 103 from entering the second light source 150. This makes it possible to reduce unnecessary light.

[0031] [Light Emitted from Second Light Source] Fig. 3 is a diagram illustrating an example of light emitted from the second light source according to an embodiment of the present disclosure. This diagram illustrates an example of light emitted from the second light source 150, and is a diagram illustrating the spectrum of the light (white light) emitted from the second light source 150. Graph 300 in Fig. 3 represents the spectrum. The horizontal axis of Fig. 3 represents wavelength in units of nm. The vertical axis represents relative intensity. Graph 300 has two peaks. The peak value λw on the short wavelength side is based on the excitation light of the light-emitting element 151. The peak value λf on the long wavelength side is based on the fluorescence of the phosphor 152.

[0032] [Characteristics of the Multiplexing Unit] FIG. 4 is a diagram illustrating an example of the characteristics of the multiplexing unit according to an embodiment of the present disclosure. This diagram illustrates an example of the characteristics of the multiplexing unit 130. Graph 301 in FIG. 4 is a graph illustrating the relationship between wavelength and reflectance of the multiplexing unit 130. The horizontal axis of FIG. 4 represents wavelength, and the vertical axis represents reflectance. Note that dashed line graph 302 in FIG. 4 represents the spectrum of excitation light (light in the first wavelength band) from the first light source 110. This light in the first wavelength band is light having a peak value λp. As illustrated in FIG. 4, the multiplexing unit 130 reflects light in the second wavelength band (peak value λw) and light in the third wavelength band (peak value λf). On the other hand, the multiplexing unit 130 exhibits low reflectance for light in the first wavelength band (peak value λp). Therefore, light in the first wavelength band is transmitted through the multiplexing unit 130. Since the reflectance of the multiplexer 130 for the first wavelength band is not “0”, part of the light in the first wavelength band is reflected by the multiplexer 130 .

[0033] [Filter Characteristics] FIG. 5 is a diagram illustrating an example of filter characteristics according to an embodiment of the present disclosure. This diagram illustrates an example of the characteristics of the filter 170. Graph 303 in FIG. 5 is a graph illustrating the relationship between wavelength and transmittance of the filter 170. The horizontal axis of FIG. 5 represents wavelength, and the vertical axis represents transmittance. As illustrated in FIG. 5, the filter 170 is configured as a band-stop filter. That is, the filter 170 transmits light in the second wavelength band (peak value λw) and light in the third wavelength band (peak value λf). On the other hand, the filter 170 has a transmittance of approximately "0" for light in the first wavelength band (peak value λp). Therefore, the return light 103 in the first wavelength band is attenuated by the filter 170. Because the light in the first wavelength band attenuated by the filter 170 is light in the valley region of the emission spectrum in FIG. 3, the color of the light from the second light source 150 can be maintained even when the filter 170 is provided. Note that a notch filter that attenuates light in λp can also be used as the filter 170.

[0034] [Other Characteristics of the Filter] FIG. 6 is a diagram illustrating another example of the characteristics of a filter according to an embodiment of the present disclosure. Similar to FIG. 5, FIG. 6 illustrates an example of the characteristics of the filter 170. Note that the dashed line graph 304 in FIG. 6 represents the spectrum of excitation light (light in the first wavelength band) from the first light source 110. This graph illustrates an example in which the light in the first wavelength band is ultraviolet light. In this case, the light in the first wavelength band (peak value λp) has a shorter wavelength band than the light in the second wavelength band (peak value λw). Graph 305 in FIG. 6 represents the relationship between the wavelength and transmittance of the filter 170. The filter 170 in FIG. 6 is configured as a low-pass filter. That is, the filter 170 in FIG. 6 transmits light in the second wavelength band (peak value λw) and light in the third wavelength band (peak value λf) and attenuates light in the first wavelength band (peak value λp), which has a shorter wavelength band than these lights.

[0035] In this way, the light source device 100 according to the first embodiment of the present disclosure attenuates light of the first wavelength band by the filter 170 disposed between the second light source 150 and the multiplexing unit 130. This prevents light of the first wavelength band (return light 103) emitted from the first light source 110 and reflected by the light guiding unit 40 or the like from entering the second light source 150. This makes it possible to reduce unnecessary light caused by the return light 103. This makes it possible to reduce noise during fluorescence observation, enabling the generation of clear fluorescence images.

[0036] Furthermore, the light source device 100 can prevent unnecessary light other than the drug fluorescence from being irradiated onto the observation target 2. This allows the surgeon to reliably determine that the light from the observation target 2 is the drug fluorescence. In other words, it is possible to improve the probability of determining that a positive reaction has occurred in the living body based on the state in which the drug is glowing, and to prevent false positive diagnoses.

[0037] (2. Second Embodiment) The light source device 100 of the first embodiment described above has the filter 170 disposed therein to attenuate the return light 103. In contrast, the light source device 100 of the second embodiment of the present disclosure differs from the first embodiment described above in that the position of the filter 170 is adjusted.

[0038] [Configuration of Light Source Device] Fig. 7 is a diagram showing a configuration example of a light source device according to a second embodiment of the present disclosure. Similar to Fig. 2, Fig. 7 is a block diagram showing a configuration example of a light source device 100. The light source device 100 in Fig. 7 differs from the light source device 100 in Fig. 2 in that the filter 170 is disposed at an angle with respect to the optical path along which light from the second light source 150 passes.

[0039] The return light 103 is attenuated by the filter 170, but some of the return light 103 may be reflected by the filter 170. If the filter 170 is disposed in a direction perpendicular to the optical path along which the light from the second light source 150 passes, the return light 103 reflected by the filter 170 travels back and forth between the incident ends 42 and enters the filter 170 again. In this case, the return light 103 increases.

[0040] Therefore, as described above, the filter 170 is disposed at an angle with respect to the optical path along which the light from the second light source 150 passes. This makes it possible to prevent the return light 103 reflected by the filter 170 from entering the incident end 42.

[0041] Other than this, the configuration of the light source device 100 is the same as the configuration of the light source device 100 in the first embodiment of the present disclosure, and therefore a description thereof will be omitted.

[0042] In this way, in the light source device 100 according to the second embodiment of the present disclosure, the filter 170 is disposed at an angle with respect to the optical path along which the light from the second light source 150 passes. This makes it possible to reduce the returning light 103 and further reduce unnecessary light.

[0043] 3. Third Embodiment The light source device 100 of the first embodiment described above uses the condenser lens 140 to condense the light from the first light source 110 and the light from the second light source 150 onto the incident end 42. In contrast, the light source device 100 of the third embodiment of the present disclosure differs from the first embodiment described above in that the condensing position of the condenser lens 140 is adjusted.

[0044] [Configuration of Light Source Device] Fig. 8 is a diagram showing an example configuration of a light source device according to a third embodiment of the present disclosure. Similar to Fig. 2, Fig. 8 is a block diagram showing an example configuration of the light source device 100. Note that some components of the light source device 100 in Fig. 8 are omitted. The light source device 100 in Fig. 8 differs from the light source device 100 in Fig. 2 in that the condenser lens 140 condenses light from the second light source at a position shifted in the optical path direction from the incident end 42 of the light guiding unit 40.

[0045] The dotted line in Fig. 8 represents light 102 from second light source 150. Condenser lens 140 in Fig. 8 condenses light 102 just before incident end 42 of light-guiding unit 40. That is, condenser lens 140 in Fig. 8 forms focal point 310 at a position shifted in the optical path direction from incident end 42. In this way, light source device 100 in Fig. 8 defocuses light from second light source 150. Therefore, return light 103 reflected at incident end 42 is also defocused with respect to the exit surface of second light source 150. This makes it possible to reduce return light 103 entering second light source 150.

[0046] Other than this, the configuration of the light source device 100 is the same as the configuration of the light source device 100 in the first embodiment of the present disclosure, and therefore a description thereof will be omitted.

[0047] In this way, the light source device 100 according to the third embodiment of the present disclosure can reduce the return light 103 incident on the second light source 150 by adjusting the focusing position of the focusing lens 140. This makes it possible to further reduce unnecessary light.

[0048] (4. Configuration of the Imaging Apparatus) The configuration of the imaging apparatus 10 will be described.

[0049] 9 is a diagram illustrating an example configuration of an imaging device according to an embodiment of the present disclosure. The figure is a block diagram illustrating an example configuration of an imaging device 10. The imaging device 10 includes a color filter 11, imaging lenses 12 and 13, and an imaging element 14.

[0050] The color filter 11 is an optical filter that transmits a predetermined wavelength of incident light. A filter that transmits light in the second and third wavelength bands and attenuates light in the first wavelength band can be used as the color filter 11 in FIG. 9 . The imaging lenses 12 and 13 focus the incident light that has passed through the color filter 11 onto the imaging element 14. The imaging element 14 generates an image (image signal) based on the incident light from the object of observation. The generated image is output to the CCU 30.

[0051] (5. Application Examples) The technology according to the present disclosure can be applied to a medical imaging system. A medical imaging system is a medical system that uses imaging technology, such as an endoscope system or a microscope system.

[0052] [Endoscopic System] An example of an endoscope system will be described with reference to FIGS. 10 and 11 . FIG. 10 is a diagram illustrating an example of the schematic configuration of an endoscope system 5000 to which the technology according to the present disclosure can be applied. FIG. 11 is a diagram illustrating an example of the configuration of an endoscope 5001 and a CCU (Camera Control Unit) 5039. FIG. 10 illustrates a state in which an operator (e.g., a doctor) 5067, who is a surgical participant, is performing surgery on a patient 5071 on a patient bed 5069 using the endoscope system 5000. As shown in FIG. 10 , the endoscope system 5000 includes an endoscope 5001, which is a medical imaging device, a CCU 5039, a light source device 5043, a recording device 5053, an output device 5055, and a support device 5027 that supports the endoscope 5001.

[0053] In endoscopic surgery, an insertion aid called a trocar 5025 is inserted into a patient 5071. Then, a scope 5003 and surgical tools 5021 connected to an endoscope 5001 are inserted into the body of the patient 5071 via the trocar 5025. The surgical tools 5021 are, for example, energy devices such as an electric scalpel, forceps, etc.

[0054] A surgical image, which is a medical image showing the inside of the body of a patient 5071 photographed by an endoscope 5001, is displayed on a display device 5041. An operator 5067 performs a procedure on the surgical target using a surgical tool 5021 while viewing the surgical image displayed on the display device 5041. Note that the medical image is not limited to a surgical image, and may be a diagnostic image photographed during a diagnosis.

[0055] [Endoscope] The endoscope 5001 is an imaging unit that captures images of the inside of the body of a patient 5071. For example, as shown in FIG. 11 , the endoscope 5001 is a camera 5005 that includes a focusing optical system 50051 that focuses incident light, a zoom optical system 50052 that changes the focal length of the imaging unit to enable optical zoom, a focus optical system 50053 that changes the focal length of the imaging unit to enable focus adjustment, and a light-receiving element 50054. The endoscope 5001 generates pixel signals by focusing light onto the light-receiving element 50054 via a connected scope 5003, and outputs the pixel signals to the CCU 5039 via a transmission system. The scope 5003 has an objective lens at its tip and is an insertion section that guides light from a connected light source device 5043 into the body of the patient 5071. The scope 5003 is, for example, a rigid scope if it is a rigid endoscope or a flexible scope if it is a flexible endoscope. The scope 5003 may be a direct-view endoscope or an oblique-view endoscope. Furthermore, the pixel signal may be a signal based on a signal output from a pixel, such as a RAW signal or an image signal. Furthermore, a configuration may be adopted in which a memory is installed in the transmission system connecting the endoscope 5001 and the CCU 5039, and parameters related to the endoscope 5001 and the CCU 5039 are stored in the memory. The memory may be located, for example, in a connection portion of the transmission system or on a cable. For example, parameters at the time of shipment of the endoscope 5001 and parameters that change when power is applied may be stored in the memory of the transmission system, and the operation of the endoscope may be changed based on parameters read from the memory. Furthermore, the endoscope and the transmission system may be collectively referred to as an endoscope. The light-receiving element 50054 is a sensor that converts received light into a pixel signal, and is, for example, a CMOS (Complementary Metal Oxide Semiconductor) type image sensor. It is preferable that the light-receiving element 50054 be an image sensor capable of color imaging with a Bayer array. Furthermore, the light receiving element 50054 is preferably an imaging element having a number of pixels corresponding to a resolution of, for example, 4K (3840 horizontal pixels × 2160 vertical pixels), 8K (7680 horizontal pixels × 4320 vertical pixels), or square 4K (3840 or more horizontal pixels × 3840 or more vertical pixels). The light receiving element 50054 may be a single sensor chip or multiple sensor chips.For example, a prism may be provided to separate incident light into predetermined wavelength bands, and each wavelength band may be imaged by a different light-receiving element. Alternatively, multiple light-receiving elements may be provided for stereoscopic vision. The light-receiving element 50054 may be a sensor including an image processing circuit within its chip structure, or a Time of Flight (ToF) sensor. The transmission system may be, for example, an optical fiber cable or wireless transmission. Wireless transmission may be performed via any means capable of transmitting pixel signals generated by the endoscope 5001. For example, the endoscope 5001 and the CCU 5039 may be connected wirelessly, or the endoscope 5001 and the CCU 5039 may be connected via a base station in the operating room. In this case, the endoscope 5001 may simultaneously transmit not only pixel signals but also information related to the pixel signals (e.g., pixel signal processing priority, synchronization signal, etc.). The endoscope may be configured such that the scope and camera are integrated, or a light-receiving element is provided at the tip of the scope.

[0056] [CCU (Camera Control Unit)] The CCU 5039 is a control device that comprehensively controls the connected endoscope 5001 and light source device 5043. For example, as shown in FIG. 11 , the CCU 5039 is an information processing device having an FPGA 50391, a CPU 50392, a RAM 50393, a ROM 50394, a GPU 50395, and an I / F 50396. The CCU 5039 may also comprehensively control the connected display device 5041, recording device 5053, and output device 5055. For example, the CCU 5039 controls the irradiation timing, irradiation intensity, and type of irradiation light source of the light source device 5043. The CCU 5039 also performs image processing such as development processing (e.g., demosaic processing) and correction processing on pixel signals output from the endoscope 5001, and outputs the processed pixel signals (e.g., an image) to an external device such as the display device 5041. Furthermore, the CCU 5039 transmits a control signal to the endoscope 5001 to control the driving of the endoscope 5001. The control signal is, for example, information regarding imaging conditions such as the magnification and focal length of the imaging unit. The CCU 5039 may have an image down-conversion function and be configured to be able to simultaneously output a high-resolution (e.g., 4K) image to the display device 5041 and a low-resolution (e.g., HD) image to the recording device 5053.

[0057] The CCU 5039 may also be connected to external devices (e.g., recording devices, display devices, output devices, and support devices) via an IP converter that converts signals into a predetermined communication protocol (e.g., IP (Internet Protocol)). The connection between the IP converter and the external devices may be configured as a wired network, or a partial or entire network may be configured as a wireless network. For example, the IP converter on the CCU 5039 side may have a wireless communication function and transmit the received video to an IP switcher or an output-side IP converter via a wireless communication network such as a fifth-generation mobile communication system (5G) or a sixth-generation mobile communication system (6G).

[0058] [Light Source Device] The light source device 5043 is a device capable of emitting light in a predetermined wavelength band and includes, for example, multiple light sources and a light source optical system that guides the light from the multiple light sources. The light sources are, for example, a xenon lamp, an LED light source, or an LD light source. The light source device 5043 has, for example, LED light sources corresponding to the three primary colors R, G, and B, and emits white light by controlling the output intensity and output timing of each light source. Furthermore, the light source device 5043 may include a light source that can emit special light used for special light observation, in addition to a light source that emits normal light used for normal light observation. The special light is light in a predetermined wavelength band different from the normal light used for normal light observation, such as near-infrared light (light with a wavelength of 760 nm or more), infrared light, blue light, or ultraviolet light. The normal light is, for example, white light or green light. Narrowband light observation, a type of special light observation, alternately emits blue light and green light to utilize the wavelength-dependence of light absorption in body tissue, enabling high-contrast imaging of specific tissue, such as blood vessels on the surface of the mucous membrane. Furthermore, in fluorescence observation, a type of special light observation, excitation light is applied to excite a drug injected into the body tissue, and fluorescence emitted by the drug as a marker is received to obtain a fluorescence image, thereby making it easier for the surgeon to visualize body tissues that are difficult for the surgeon to see under normal light. For example, in fluorescence observation using infrared light, infrared light having an excitation wavelength band is applied to a drug such as indocyanine green (ICG) injected into the body tissue, and the fluorescence of the drug is received, making it easier to visualize the structure of the body tissue and affected areas. Furthermore, in fluorescence observation, a drug (e.g., 5-ALA) that is excited by special light in the blue wavelength band and emits fluorescence in the red wavelength band may be used. The type of light irradiated by the light source device 5043 is set under the control of the CCU 5039. The CCU 5039 may have a mode in which normal light observation and special light observation are alternately performed by controlling the light source device 5043 and the endoscope 5001. In this case, it is preferable to superimpose information based on pixel signals obtained by special light observation on pixel signals obtained by normal light observation. The special light observation may be infrared light observation, which irradiates infrared light to view areas deeper than the surface of an organ, or multispectral observation using hyperspectral spectroscopy. Furthermore, photodynamic therapy may be combined.

[0059] [Recording Device] The recording device 5053 is a device, such as a recorder, that records pixel signals (e.g., images) acquired from the CCU 5039. The recording device 5053 records images acquired from the CCU 5039 on a HDD, SSD, or optical disk. The recording device 5053 may be connected to a network within the hospital so as to be accessible from devices outside the operating room. The recording device 5053 may also have an image down-conversion or up-conversion function.

[0060] [Display Device] The display device 5041 is a device capable of displaying an image, such as a display monitor. The display device 5041 displays an image based on pixel signals acquired from the CCU 5039. The display device 5041 may also function as an input device that enables gaze recognition, voice recognition, and instruction input using gestures by including a camera and a microphone.

[0061] [Output Device] The output device 5055 is a device, such as a printer, that outputs information acquired from the CCU 5039. The output device 5055 prints, for example, a print image based on pixel signals acquired from the CCU 5039 onto paper.

[0062] [Support Device] The support device 5027 is an articulated arm including a base 5029 having an arm control device 5045, an arm 5031 extending from the base 5029, and a holder 5032 attached to the tip of the arm 5031. The arm control device 5045 is configured with a processor such as a CPU and controls the drive of the arm 5031 by operating according to a predetermined program. The support device 5027 controls the position and posture of the endoscope 5001 held by the holder 5032, for example, by controlling parameters such as the length of each link 5035 constituting the arm 5031 and the rotation angle and torque of each joint 5033 using the arm control device 5045. This allows the endoscope 5001 to be changed to a desired position or posture, allowing the scope 5003 to be inserted into the patient 5071 and the observation area within the body to be changed. The support device 5027 functions as an endoscope support arm that supports the endoscope 5001 during surgery. This allows the support device 5027 to take the place of an assistant scopist who holds the endoscope 5001. The support device 5027 may also be a device that supports a microscope device 5301 (described later) and may also be called a medical support arm. The support device 5027 may be controlled autonomously by the arm control device 5045, or may be controlled by the arm control device 5045 based on user input. For example, the control method may be a master-slave method in which the support device 5027, which serves as a slave device (replica device) serving as a patient cart, is controlled based on the movement of a master device (primary device) that serves as an operator console near the user. The support device 5027 may also be remotely controlled from outside the operating room.

[0063] The above describes an example of an endoscope system 5000 to which the technology according to the present disclosure can be applied. For example, the technology according to the present disclosure may be applied to a microscope system.

[0064] 12 is a diagram showing an example of the schematic configuration of a microsurgical system to which the technology according to the present disclosure can be applied. In the following description, components similar to those in the endoscope system 5000 are designated by the same reference numerals, and redundant description thereof will be omitted.

[0065] 12 is a schematic illustration of an operator 5067 performing surgery on a patient 5071 on a patient bed 5069 using a microsurgical system 5300. For simplicity, the illustration of the cart 5037 of the microsurgical system 5300 is omitted, and a microscope device 5301 that replaces the endoscope 5001 is simplified. However, the microscope device 5301 in this description may refer to the microscope unit 5303 provided at the tip of the link 5035, or may refer to the entire configuration including the microscope unit 5303 and the support device 5027.

[0066] 12 , during surgery, a microsurgical system 5300 is used to capture an image of the surgical site captured by a microscope device 5301 and display it enlarged on a display device 5041 installed in an operating room. The display device 5041 is installed in a position facing the surgeon 5067, who performs various procedures on the surgical site, such as resecting the affected area, while observing the state of the surgical site using the image displayed on the display device 5041. Microsurgical systems are used, for example, in ophthalmic surgery and brain surgery.

[0067] The above describes examples of an endoscopic system 5000 and a microsurgery system 5300 to which the technology of the present disclosure can be applied. Note that the systems to which the technology of the present disclosure can be applied are not limited to these examples. For example, the support device 5027 may support another observation device or another surgical tool at its tip instead of the endoscope 5001 or the microscope unit 5303. Examples of such other observation devices include forceps, a surgeon, an insufflation tube for insufflation, or an energy treatment tool for incising tissue or sealing blood vessels by cauterization. Supporting these observation devices and surgical tools with a support device allows them to be more stably fixed in position than when medical staff support them manually, and also reduces the burden on medical staff. The technology of the present disclosure may be applied to support devices that support components other than the microscope unit.

[0068] Of the configurations described above, the technology according to the present disclosure can be suitably applied to the light source device 5043. Specifically, the light source device 100 in FIG. 1 can be applied to the light source device 5043. By applying the technology according to the present disclosure to the light source device 5043, a clearer image of the surgical site can be obtained, making it possible to perform surgery more safely and reliably.

[0069] The configuration of the second embodiment of the present disclosure can be applied to other embodiments. Specifically, the filter 170 in Fig. 7 can be applied to the third embodiment of the present disclosure.

[0070] Although the embodiments of the present disclosure have been described above, the technical scope of the present disclosure is not limited to the above-described embodiments, and various modifications are possible within the scope of the gist of the present disclosure. Furthermore, components of different embodiments and modifications may be combined as appropriate.

[0071] The effects described in this specification are merely examples and are not limiting, and other effects may also be present.

[0072] The present technology may also be configured as follows: (1) A light source device comprising: a first light source that emits light including a first wavelength band; a second light source that emits light including a second wavelength band excited by a phosphor; a multiplexing section that multiplexes light from the first light source and light from the second light source; and a filter that is disposed between the multiplexing section and the second light source and transmits light of the second wavelength band and attenuates light of the first wavelength band. (2) The light source device according to (1), wherein the second light source comprises a light-emitting element that emits excitation light of the second wavelength band and a phosphor that is excited by the excitation light to emit fluorescence of a third wavelength band, and the light source emits light including the excitation light and the fluorescence. (3) The light source device according to (2), wherein the first light source emits light including the first wavelength band included in a wavelength band between the wavelength band of the excitation light and the wavelength band of the fluorescence. (4) The light source device according to (2), wherein the second light source includes the light-emitting element that emits blue excitation light and the phosphor that emits yellow fluorescence. (5) The light source device according to any of (1) to (4), wherein the multiplexing unit multiplexes the light from the first light source and the light from the second light source by integrating the optical path through which the light from the first light source passes and the optical path through which the light from the second light source passes. (6) The light source device according to any of (1) to (5), further including: a first collimating lens that collimates the light from the first light source and causes it to enter the multiplexing unit; and a second collimating lens that collimates the light from the second light source and causes it to enter the multiplexing unit, wherein the filter is disposed between the second collimating lens and the multiplexing unit. (7) The light source device according to any of (1) to (6), wherein the filter is disposed at an angle with respect to the optical path through which the light from the second light source passes. (8) The light source device according to any one of (1) to (7), further comprising a condenser lens that condenses the combined light from the first light source and the light from the second light source at an input end of a light guiding section that guides the light from the first light source and the light from the second light source. (9) The light source device according to (8), wherein the condenser lens condenses the light from the second light source at a position shifted in the optical path direction from the input end of the light guiding section.(10) An endoscope system comprising: a light source device including: a first light source that emits light including a first wavelength band; a second light source that emits light including a second wavelength band excited by a phosphor; a multiplexing section that multiplexes the light from the first light source and the light from the second light source; and a filter that is disposed between the multiplexing section and the second light source and transmits light of the second wavelength band and attenuates light of the first wavelength band; a light guide section that guides the light from the first light source and the light from the second light source; and an imaging device that images an area irradiated with either the guided light from the first light source or the light from the second light source.

[0073] REFERENCE SIGNS LIST 1 Endoscope system 10 Imaging device 40 Light guide section 42 Incident end 100, 5043 Light source device 110 First light source 120, 160 Parallel light lens 130 Wave-combining section 140 Condenser lens 150 Second light source 151 Light-emitting element 152 Phosphor 170 Filter

Claims

1. A light source device comprising: a first light source that emits light including a first wavelength band; a second light source that emits light including a second wavelength band excited by a phosphor; a multiplexing section that multiplexes the light from the first light source and the light from the second light source; and a filter that is disposed between the multiplexing section and the second light source and transmits the light of the second wavelength band and attenuates the light of the first wavelength band.

2. The light source device according to claim 1, wherein the second light source comprises a light-emitting element that emits excitation light in the second wavelength band and a phosphor that is excited by the excitation light to emit fluorescence in a third wavelength band, and emits light including the excitation light and the fluorescence.

3. A light source device according to claim 2, wherein the first light source emits light including the first wavelength band included in a wavelength band between the wavelength band of the excitation light and the wavelength band of the fluorescent light.

4. A light source device according to claim 2, wherein the second light source comprises a light emitting element that emits blue excitation light and a phosphor that emits yellow fluorescent light.

5. A light source device as described in claim 1, wherein the multiplexing section multiplexes the light from the first light source and the light from the second light source by integrating an optical path through which the light from the first light source passes and an optical path through which the light from the second light source passes.

6. The light source device according to claim 1, further comprising: a first collimating lens that converts the light from the first light source into parallel light and causes it to enter the multiplexing section; and a second collimating lens that converts the light from the second light source into parallel light and causes it to enter the multiplexing section, wherein the filter is disposed between the second collimating lens and the multiplexing section.

7. The light source device according to claim 1, wherein the filter is disposed at an angle with respect to an optical path along which the light from the second light source passes.

8. A light source device as described in claim 1, further comprising a focusing lens that focuses the combined light from the first light source and the light from the second light source at an incident end of a light guiding section that guides the light from the first light source and the light from the second light source.

9. The light source device according to claim 8, wherein said focusing lens focuses the light from said second light source at a position shifted in the optical path direction from the input end of said light guiding section.

10. An endoscope system comprising: a light source device having: a first light source that emits light including a first wavelength band; a second light source that emits light including a second wavelength band excited by a phosphor; a multiplexing section that multiplexes light from the first light source and light from the second light source; and a filter that is disposed between the multiplexing section and the second light source and transmits light of the second wavelength band and attenuates light of the first wavelength band; a light guiding section that guides the light from the first light source and the light from the second light source; and an imaging device that images an area irradiated with either the guided light from the first light source or the light from the second light source.

Images