Medical observation system and medical observation method

Abstract

[Problem] To provide a technique that facilitates observation of an observation target with a plurality of observation lights having different wavelength bands. [Solution] A medical observation system comprising: a light source device that emits broadband light of a first wavelength band, first narrow-band light that excites a first substance that emits first fluorescent light of a wavelength band included in the first wavelength band, and second narrow-band light that excites a second substance that emits second fluorescent light of a wavelength band included in the second wavelength band; the second narrowband light excites a second substance that emits a second fluorescent light of a wavelength band that is not included in the first wavelength band; and a control unit for controlling the light source apparatus, in which the control unit controls the light source apparatus in such a manner that the broadband light and the first narrowband light are irradiated to the observation target in a time-sharing manner in a first mode, and in such a manner that the broadband light and the second narrowband light are irradiated to the observation target in a second mode different from the first mode.

Description

TECHNICAL FIELD

[0001] The present application relates to a medical observation system and a medical observation method. BACKGROUND

[0002] Fluorescence observation, which determines the state of biological tissue (living tissue) by irradiating the biological tissue with excitation light containing a fluorescent substance and observing fluorescence emitted from the biological tissue, is expanding in demand (see, for example, Patent Literature 1).

[0003] Through fluorescence, it is possible to understand the state of tissue that is difficult to identify in a case where reflected light of visible light (such as white light with which the biological tissue to be observed is irradiated) is observed. Therefore, fluorescence observation can be used for various purposes and applications, such as identification of a lesion.

[0004] LIST OF CITATIONS

[0005] PATENT LITERATURE

[0006] Patent Literature 1: Japanese Patent Application Publication No. 2021-132695 SUMMARY

[0007] PROBLEMS TO BE SOLVED BY THE INVENTION

[0008] In fluorescence observation, various agents according to the characteristics of the biological tissue to be observed can be used, for example, an agent that emits fluorescence of a visible light wavelength band or an agent that emits fluorescence of a wavelength band other than the visible light wavelength band can be injected into the biological tissue.

[0009] Further, fluorescence observation is performed in combination with reflected light observation that observes reflected light of visible light (observation of an observation target with visible light), whereby it is possible to more accurately and easily determine the state of the observation target.

[0010] By observing the target tissue in this way using observation light of various wavelength bands, it is possible to determine the state and characteristics of the observation target in a multi-faceted and comprehensive manner.

[0011] The present disclosure provides techniques that facilitate observation of an observation target via multiple types of observation light having different wavelength bands.

[0012] SOLUTION TO PROBLEM

[0013] An aspect of the present disclosure relates to a medical observation system including: a light source device that emits broadband light of a first wavelength band, first narrowband light, and second narrowband light; a first substance that excites a first fluorescence that emits a wavelength band included in the first wavelength band, and a second substance that excites a second fluorescence that emits a wavelength band not included in the first wavelength band, by the first narrowband light and the second narrowband light, respectively; and a control section that controls the light source device, wherein the control section is configured to control the light source device such that, in a first mode, the broadband light and the first narrowband light are emitted to an observation target in a time-division manner, and control the light source device such that, in a second mode different from the first mode, the broadband light and the second narrowband light are emitted to the observation target.

[0014] Another aspect of the present disclosure relates to a medical observation method including: a step of emitting, from a light source device, at least one light of broadband light of a first wavelength band, first narrowband light that excites a first substance that emits a first fluorescence, and second narrowband light that excites a second substance that emits a second fluorescence; the first fluorescence is within a wavelength band included in the first wavelength band, and the second fluorescence is within a wavelength band not included in the first wavelength band, wherein, in a first mode, the broadband light and the first narrowband light are emitted from the light source device such that the broadband light and the first narrowband light are emitted to an observation target in a time-division manner, and, in a second mode different from the first mode, the broadband light and the second narrowband light are emitted from the light source device such that the observation target is irradiated with the broadband light and the second narrowband light. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1A is a diagram illustrating an example of a medical observation system.

[0016] Figure 1B is a diagram illustrating another example of a medical observation system.

[0017] Figure 2 is a diagram illustrating an example of a schematic configuration of a light source device.

[0018] Figure 3 is a diagram illustrating an example of a schematic configuration of an imaging system of a camera head.

[0019] Figure 4 is a diagram illustrating another example of a schematic configuration of an imaging system of a camera head.

[0020] Figure 5 is a diagram illustrating another example of a schematic configuration of an imaging system of a camera head.

[0021] Figure 6 is a diagram illustrating another example of a schematic configuration of an imaging system of a camera head.

[0022] Figure 7is a block diagram showing a configuration example of a camera head and a control device.

[0023] Figure 8 An example of an output image displayed on a display device is shown.

[0024] Figure 9 Another example of an output image displayed on a display device is shown.

[0025] Figure 10 Another example of an output image displayed on a display device is shown.

[0026] Figure 11 Another example of an output image displayed on a display device is shown.

[0027] Figure 12 is a diagram for explaining a type of light incident to imaging elements (first and second imaging elements) according to the first embodiment.

[0028] Figure 13 An example of a timing chart of light source emission and imaging element exposure in the first mode of the first embodiment is shown.

[0029] Figure 14 An example of a timing chart of light source emission and imaging element exposure in the second mode of the first embodiment is shown.

[0030] Figure 15 Another example of a timing chart of light source emission and imaging element exposure in the second mode of the first embodiment is shown.

[0031] Figure 16 is a diagram for explaining a type of light incident to imaging elements (first and second imaging elements) according to the second embodiment.

[0032] Figure 17 is a diagram for explaining a type of light incident to imaging elements (first and second imaging elements) according to the third embodiment.

[0033] Figure 18 An example of a timing chart of light source emission and imaging element exposure in the first mode of the third embodiment is shown.

[0034] Figure 19 is a diagram for explaining a type of light incident to imaging elements (first and second imaging elements) according to the fourth embodiment.

[0035] Figure 20 is a diagram for explaining a type of light incident to imaging elements (first and second imaging elements) according to the fifth embodiment.

[0036] Figure 21 is a diagram for explaining a type of light incident to an imaging element (a first imaging element, a second imaging element, and a third imaging element) according to a sixth embodiment.

[0037] Figure 22 An example of a timing chart of light source emission and imaging element exposure in a third mode of the seventh embodiment is shown.

[0038] Figure 23 is a diagram for explaining a type of light incident to an imaging element (a first imaging element, a second imaging element, and a third imaging element) according to an eighth embodiment.

[0039] Figure 24 is a diagram for explaining a type of light incident to an imaging element (a first imaging element, a second imaging element, and a third imaging element) according to a ninth embodiment.

[0040] Figure 25 An example of a timing chart of light source emission and imaging element exposure in a fifth mode of the ninth embodiment is shown.

[0041] Figure 26 is a diagram for explaining a type of light incident to an imaging element (a first imaging element, a second imaging element, and a third imaging element) according to a tenth embodiment.

[0042] Figure 27 is a flowchart showing an example of a medical observation method executed by a medical observation system.

[0043] Figure 28 A diagram showing an example of a physical size relationship of an imaging region (effective pixel region) of a first imaging element and an imaging region (effective pixel region) of a second imaging element is shown.

[0044] Figure 29 is a diagram showing an example of a first image generated on the basis of an image signal from a first imaging element shown in Figure 28

[0045] Figure 30 is a diagram for explaining an example of a generation process of a first image, a second image, and a superimposition image in a first image generation example.

[0046] Figure 31 An example of a first output image generated mainly from a first image (normal light capture image) that is a captured image of a first imaging element is shown.

[0047] Figure 32 ​An example of a second output image generated mainly from a second image (fluorescence captured image) that is a captured image of the second imaging element is shown.

[0048] Figure 33 is a view for illustrating an example of an output image generation process in the first image generation example.

[0049] Figure 34A is a flowchart showing an example of a generation process of a superimposed output image.

[0050] Figure 34B is a flowchart showing an example of a generation process of a superimposed output image.

[0051] Figure 34C is a flowchart showing an example of a generation process of a superimposed output image.

[0052] Figure 35 is a view for illustrating an example of a generation process of a first image, a second image, and a superimposed image in the second image generation example.

[0053] Figure 36 is a view for illustrating an example of an output image generation process in the second image generation example.

[0054] Figure 37 is a conceptual view showing an example of a medical observation system configured as a surgical field illumination observation device in which a ring light (a photopic field illumination device for living body observation) is connected to a light source apparatus.

[0055] Figure 38 is a view showing an example of a medical observation system configured as a microscope system. DETAILED DESCRIPTION

[0056] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. The same or corresponding elements are denoted by the same reference numerals, and detailed description thereof will be appropriately omitted. Further, unless otherwise indicated, the terms "first", "second" and the like do not limit the specific order and do not indicate the importance, and are used only for the purpose of distinction.

[0057] Hereinafter, a case where the present technology is applied to an endoscope apparatus will be exemplified. However, the application target of the present disclosure is not limited to this, and the present disclosure can also be applied to medical observation systems, devices, and methods other than endoscope apparatuses. The term "medical care" as used herein is interpreted in a broad sense, and is a concept that can include not only treatment of diseases and injuries but also various actions for the purpose of maintaining, restoring, or promoting health, and actions for the main purpose of research are also included in the concept of "medical care".

[0058] [Medical observation system]

[0059] Figure 1A is a diagram showing an example of a medical observation system 100.

[0060] Figure 1A The medical observation system 100 shown is configured as an endoscope device (endoscope system) that observes light (i.e., observation light) of an object as an observation target via capturing an image. However, as described later, the medical observation system 100 of the present example is capable of direct visual recognition of the observation light with the naked eye without capturing an image.

[0061] Figure 1A The medical observation system 100 shown includes a light source device 10, an insertion device 20 (endoscope body), a light guide 30, a camera head (imaging section) 50, a display device 70, a transmission cable 80, and a control device 90.

[0062] The light source device 10 is a device that emits light to be applied to an observation target and emits the light under the control of the control device 90 (specifically, a "control section" described later (see Figure 7 ). The light source device 10 is capable of emitting a plurality of lights different in wavelength band, such as capable of emitting one or both of visible light (white light, etc.) and invisible light (infrared light, ultraviolet light, etc.).

[0063] Figure 1A The light source device 10 shown in FIG. 1 includes a wideband light source (first light source) 11 that emits wideband light, a first narrowband light source (second light source) 12 that emits first narrowband light, and a second narrowband light source (third light source) 13 that emits second narrowband light.

[0064] The wideband light emitted from the wideband light source 11 includes light having a relatively wide wavelength band (i.e., a first wavelength band) as a main light component with respect to the narrowband light. The first wavelength band of the wideband light can be a continuous single wavelength band, or can include a plurality of discrete wavelength bands.

[0065] On the other hand, the first narrowband light and the second narrowband light emitted from each of the first narrowband light source 12 and the second narrowband light source 13 include light in a relatively narrow wavelength band with respect to the wideband light as a main light component. The first narrowband light is included in the first wavelength band as the wavelength band of the wideband light, partially or entirely, has a narrower band width than the first wavelength band, and is capable of light that excites a first substance that emits first fluorescent light. The first fluorescent light also has a narrower band width than the first wavelength band.

[0066] The entire wavelength band of the second narrow-band light is not included in the first wavelength band and has a narrower bandwidth than the first wavelength band, and is capable of exciting a second substance that emits second fluorescent light. The wavelength band of the second narrow-band light can be a wavelength band on the longer-wavelength side or a wavelength band on the shorter-wavelength side than the first wavelength band of the wide-band light and the wavelength band of the first narrow-band light. The second fluorescent light also has a narrower bandwidth than the first wavelength band, and can be a wavelength band on the longer-wavelength side or a wavelength band on the shorter-wavelength side than the first wavelength band of the wide-band light and the wavelength band of the first narrow-band light.

[0067] The light source apparatus 10 is connected to the insertion device 20 via the light guide 30, and light emitted from the light source apparatus 10 is transmitted to the insertion device 20 via the light guide 30. The light guide 30 of the present example is detachably connected to the light source apparatus 10 and the insertion device 20.

[0068] The insertion device 20 has an insertion portion 21, and an optical connection portion 22 and an imaging connection portion 23 provided on the proximal end side of the insertion portion 21. Figure 1A The insertion device 20 shown is configured as a rigid endoscope, and the insertion portion 21 has a rigid, elongated shape. However, the insertion device 20 can have any structure, and for example, can be configured as a flexible endoscope having a flexible insertion portion 21.

[0069] A light-transmitting portion (light guide) and an objective lens are provided on the end surface of the distal end portion 21a of the insertion portion 21 on the side opposite to the proximal end. Light transmitted to the insertion device 20 from the light source apparatus 10 via the light guide 30 is emitted toward the observation target from the light-transmitting portion of the end surface of the distal end portion 21a of the insertion portion 21. Then, light from the observation target is incident on the objective lens and guided to the imaging connection portion 23 via the inside of the insertion portion 21. In this way, the entire light from the observation target guided to the imaging connection portion 23 via the objective lens and the inside of the insertion portion 21 is called observation light, and for example, reflected light from the observation target and fluorescent light emitted from the observation target can be included in the observation light.

[0070] The imaging connection portion 23 is detachably connected to the connection portion of the camera head 50. The observation light transmitted through the objective lens enters the camera head 50 through the imaging connection portion 23, and is received by the camera head 50.

[0071] Note that the imaging connection portion 23 can also function as an eyepiece portion. That is, in a state where the imaging connection portion 23 is detached from the camera head 50, the operator of the insertion device 20 is able to directly observe the observation light via the imaging connection portion 23.

[0072] The camera head 50 is an imaging device detachably connected to the insertion device 20 and receiving observation light transmitted via the insertion device 20, and captures an image of an observation target irradiated with light emitted by the light source device 10 to acquire an image. The camera head 50 is connected to the control device 90 via the transmission cable 80.

[0073] The transmission cable 80 can transfer various signals (e.g., image signals, control signals, synchronization signals, and clock signals) and electric power between the camera head 50 and the control device 90. The camera head 50 outputs an image signal corresponding to the received observation light, and the image signal is transmitted from the camera head 50 to the control device 90 via the transmission cable 80.

[0074] The signal transmission method in the transmission cable 80 is not limited, and various signals as electric signals or optical signals can be transmitted via the transmission cable 80. In addition, instead of the wired signal transmission method via the transmission cable 80, various signals can be transmitted between the camera head 50 and the control device 90 by a wireless signal transmission method (e.g., wireless local area network (LAN), Bluetooth (registered trademark), infrared communication, or the like).

[0075] The control device 90 is connected to the camera head 50, the light source device 10, and the display device 70 in a wired or wireless manner, and controls the camera head 50, the light source device 10, and the display device 70 as a whole. For example, the control device 90 controls light emission of the light source device 10 described later, or generates an image from an image signal transmitted from the camera head 50 and causes the display device 70 to display the image. In addition, the control device 90 can also control the insertion device 20 connected to the camera head 50 via the camera head 50.

[0076] Note that, in the example shown in FIG. 1, the control device 90 is provided separately from the light source device 10, the camera head 50, and the display device 70, but can be provided integrally with the light source device 10, the camera head 50, and / or the display device 70. Figure 1A

[0077] The display device 70 includes a display (e.g., a liquid crystal display or an organic electroluminescence (EL) display) of an arbitrary configuration, and displays an image on the display under the control of the control device 90.

[0078] Although the display device 70 is provided separately from the light source device 10, the camera head 50, and the control device 90 in the example shown in FIG. 1, the display device 70 can be provided integrally with the light source device 10, the camera head 50, and / or the control device 90. Figure 1A ​The display device 70 is shown as a single module, but one or more display devices 70 can be connected to the control device 90 (image generation apparatus). In a case where a plurality of display devices 70 are connected to the control device 90, the same output image can be displayed on the plurality of display devices 70 in synchronization, or different output images can be displayed on the plurality of display devices 70 in synchronization. For example, when an output image capturing an entire observation target in an overhead perspective view is displayed on a certain display device 70, an output image zoomed in and capturing the entire or a part of the observation target can be displayed on the other display devices 70.

[0079] Figure 1B is a diagram showing another example of the medical observation system 100. In Figure 1B In the medical observation system 100 shown in Figure 1B the other configurations of the medical observation system 100 shown in Figure 1A are the same as those of the medical observation system 100 described above.

[0080] The entire wavelength band of the third narrow-band light is not included in the first wavelength band and has a narrower bandwidth than the first wavelength band, and can be used as light that excites a third substance that emits third fluorescent light having a wavelength band different from at least a part of the wavelength band of the second fluorescent light. The wavelength band of the third narrow-band light can be a wavelength band on the longer-wavelength side or a wavelength band on the shorter-wavelength side than the first wavelength band of the wide-band light and the wavelength band of the first narrow-band light. In addition, the wavelength band of the second narrow-band light and the wavelength band of the third narrow-band light can also be partially superimposed, or can not be superimposed at all. The third fluorescent light also has a narrower bandwidth than the first wavelength band, and can be a wavelength band on the longer-wavelength side or a wavelength band on the shorter-wavelength side than the first wavelength band of the wide-band light and the wavelength band of the first narrow-band light.

[0081] [Light source device]

[0082] Next, an example of the device configuration of the light source device 10 described above will be described.

[0083] Figure 2 is a diagram showing a schematic configuration of an example of the light source device 10. In Figure 2 In the light source device 10 shown in

[0084] The lens optical system 40 includes a collimator lens that converts incident light into parallel light. The mirror optical system 41 reflects light incident through the lens optical system 40 and transmits light incident through the other mirror optical system 41.

[0085] The broadband light L1 emitted from the broadband light source 11 is converted into parallel light by the corresponding lens optical system 40, is then reflected by the corresponding mirror optical system 41, is transmitted through the mirror optical system 41 associated with the other light sources 12 and 13, and is incident on the light guide 30. The first narrow-band light L2 emitted from the first narrow-band light source 12 is converted into parallel light by the corresponding lens optical system 40, is then reflected by the corresponding mirror optical system 41, is transmitted through the mirror optical system 41 associated with the second narrow-band light source 13, and is incident on the light guide 30. The second narrow-band light L3 emitted from the second narrow-band light source 13 is converted into parallel light by the corresponding lens optical system 40, is then reflected by the corresponding mirror optical system 41, and is incident on the light guide 30.

[0086] Specifically, in the light source apparatus 10 of the present example, the broadband light L1, the first narrow-band light L2, and the second narrow-band light L3 emitted from the respective light sources 11, 12, and 13 are reflected by the corresponding mirror optical systems 41, and then enter the light guide 30 through a common optical path. Thus, in a case where light emission is performed simultaneously in two or more of the broadband light source 11, the first narrow-band light source 12, and the second narrow-band light source 13, multiple types of light are incident on the light guide 30, and the observation target is irradiated with light.

[0087] Note that the light source apparatus 10 shown in Figure 2 is merely an example, and the light source apparatus 10 can adopt any other configuration, and for example, a third narrow-band light source 14 (see Figure 1B ) can be provided. Furthermore, the specific device configuration of the broadband light source 11, the first narrow-band light source 12, the second narrow-band light source 13, and the third narrow-band light source 14 is not limited, and each of the light sources 11, 12, 13, and 14 can have a single light-emitting device or can have a plurality of light-emitting devices.

[0088] Furthermore, the wavelength bands of the broadband light L1, the first narrow-band light L2, the second narrow-band light L3, and the third narrow-band light source 14 emitted by the broadband light source 11, the first narrow-band light source 12, the second narrow-band light source 13, and the third narrow-band light source 14 are also not limited.

[0089] For example, the broadband light source 11 can emit visible light as the broadband light L1 or can emit light in a wavelength band corresponding to a color gamut that can be displayed by the display apparatus 70. Visible light is light that is perceptible to a healthy human eye, and can have a wavelength band of 380 nm to 780 nm, as an example, in which the upper limit wavelength is 760 nm to 830 nm and the lower limit wavelength is 360 nm to 400 nm. Note that here, light other than visible light is referred to as non-visible light, and a wavelength band other than the visible light wavelength band is referred to as a non-visible light wavelength band.

[0090] For example, the broadband light source 11 can emit white light as the broadband light LI, and can be configured by a light emitting diode (LED), a xenon lamp, or any other device. The broadband light source 11 can be configured by a white LED that is a single color light emitting device, or can be configured by a plurality of color LEDs (e.g., a red LED, a green LED, and a blue LED) that emit light of different colors. Further, the broadband light source 11 can include a white LED and a plurality of color LEDs that emit color light other than white light.

[0091] Further, the light emitted from the broadband light source 11 can include at least a portion of light within a visible light wavelength band, and for example, can include light corresponding to a color gamut of a standard specification of the display device 70, or can include light within a specific wavelength band (e.g., violet light or green light).

[0092] The first narrow-band light source 12 can emit light that excites a substance that emits first fluorescent light having a wavelength band included in the wavelength band of the broadband light LI from the broadband light source 11 (first wavelength band) as the first narrow-band light L2. On the other hand, the second narrow-band light source 13 can emit light that excites a second substance that emits second fluorescent light having a wavelength band not included in the wavelength band of the broadband light LI from the broadband light source 11 (first wavelength band) as the second narrow-band light L3. Further, the third narrow-band light source 14 can emit light that excites a third substance that emits third fluorescent light having a wavelength band not included in the wavelength band of the broadband light LI from the broadband light source 11 (first wavelength band) as the third narrow-band light.

[0093] Each of the first narrow-band light source 12, the second narrow-band light source 13, and the third narrow-band light source 14 can include, for example, a laser light source, an LED light source, a xenon lamp, or any other light emitting device. As an example, each of the first narrow-band light source 12, the second narrow-band light source 13, and the third narrow-band light source 14 can be configured by combining such a light emitting device (e.g., a xenon lamp) and a filter (a band-pass filter) that transmits a narrow-band light of a desired wavelength band from the light emitted from the light emitting device.

[0094] Note that the broadband light LI from the broadband light source 11 can be visible light or visible light in a portion of a visible light wavelength band. Further, each of the first fluorescent light to the third fluorescent light emitted by the first substance to the third substance can emit visible light or light in a non-visible light wavelength band (e.g., infrared light or ultraviolet light).

[0095] Note that the substance (e.g., the above-described first substance to the third substance) excited by the light emitted from the light source device 10 can be a reagent or a fluorescent dye applied to an observation target, or can be a fluorescent substance that constitutes the observation target itself.

[0096] Examples of such reagents that can be applied to the observation target include 5-ALA (PP-IX), ADS780WS, ADS830WS, aggregation-induced emission point allophycocyanin (APC), boron-dipyrromethane (BODIPY), CLR 1502, flavin, fluorescamine, fluorescein, fluor-gold, green fluorescent protein, ICG (indocyanine green), IRDye 78, IR-PEG nanoparticle, isothiocyanate, rose Bengal, trypan blue, and SGM-101.

[0097] Examples of fluorescent dyes that can be applied to the observation target include coumarin, Cy3, DyLight 547, GE3126, metal nanocluster, oxacarbocyanine, rhodamine, riboflavin, fluorescein, Alexa Fluor 488, Alexa Fluor 660, Alexa Fluor 680, Alexa Fluor 700, Cy5, Cy5.5, Dy677, Dy682, Dy752, DyLight 647, HiLyte Fluor 647, HiLyte Fluor 680, IRDye 700DX, methylene blue, porphyrin, porphysome, VivoTag-680, VivoTag-S680, Alexa Fluor 750, Alexa Fluor 790, carbocyanine, conjugated copolymer, CW800-CA, Cy7, Cy7.5, fluorochrome, Dy780, HiLyte Fluor 750, indocarbocyanine, IR-786, IRDye 800CW, IRDye 800RS, IRDye 800BK, Nervelight TM , OTL-38, polyacetylene, VivoTag-S750, ASP5354, and xanthene.

[0098] Examples of fluorescent substances derived from the observation target constituting the observation target itself include collagen, elastin, and NADH.

[0099] [Camera head]

[0100] Next, an example of the configuration of the imaging system of the above-described camera head 50 will be described. Hereinafter, a typical example of a two-plate imaging module (see Figure 3 and Figure 4 ) that performs imaging using two imaging elements and a typical example of a so-called three-plate imaging module (see Figure 5 and Figure 6 ) that performs imaging using three imaging elements will be described.

[0101] Figure 3 is a diagram showing a schematic configuration of an example of the imaging system of the camera head 50.

[0102] Figure 3 The camera head 50 illustrated in FIG. 6 includes an excitation light cut filter FC, a branching optical system Bs, a first imaging element 522a, and a second imaging element 522b.

[0103] The observation light Lf that has passed through the insertion device 20 is incident on the branching optical system Bs after the light of the prescribed wavelength band is cut off by the excitation light cut filter FC.

[0104] The wavelength band of the light cut off by the excitation light cut filter FC includes the wavelength band of the excitation light that can be emitted toward the observation target. For example, in the case where the first narrow-band light to the third narrow-band light from the first narrow-band light source 12 to the third narrow-band light source 14 are irradiated as the excitation light to the observation target, the excitation light cut filter FC at least partially, substantially, or completely suppresses the light of the wavelength band of the first narrow-band light, the second narrow-band light, and the third narrow-band light. The excitation light cut filter FC can be configured by a known wavelength selection filter or the like, and prevents the reflected light of the excitation light that irradiates the observation target from being received by the imaging element (in the present example, the first imaging element 522a and the second imaging element 522b).

[0105] Note that, although Figure 3 The excitation light cut filter FC is illustrated as a single unit, but the excitation light cut filter FC can be configured by a single filter or a plurality of filters. For example, in the case where a plurality of excitation lights of different wavelength bands are irradiated to the observation target, the excitation light cut filter FC can be a single filter that partially, substantially, or completely suppresses the light of the wavelength band of these excitation lights, or can include a plurality of filters that partially, substantially, or completely suppress the light of the wavelength band of each excitation light.

[0106] In addition, the excitation light cut filter FC is not limited to Figure 3 The illustrated position can also be provided at an arbitrary position on the optical path of the observation light Lf (including the separated light flux) from the observation target to the imaging element (in the present example, the first imaging element 522a and the second imaging element 522b). That is, the excitation light cut filter FC can be provided in the insertion device 20, for example, with respect to the objective lens provided on the end surface of the distal end portion 21a of the insertion portion 21 on the upstream side or the downstream side of the traveling direction of the observation light Lf. In addition, the excitation light cut filter FC can be provided separately from the medical observation system 100.

[0107] Note that, the excitation light cut filter FC can also not be provided. In the case where the influence of the reflected light of the excitation light on the captured image is sufficiently small, the system configuration can be simplified by not providing the excitation light cut filter FC.

[0108] The branch optical system Bs is an optical element 15 that separates the observation light Lf from the observation target into a first light flux Lf1 and a second light flux Lf2 (a plurality of light fluxes) and guides the first light flux Lf1 to the first imaging element 522a and the second light flux Lf2 to the second imaging element 522b. Figure 3 The illustrated branch optical system Bs reflects the first light flux Lf1 toward the first imaging element 522a and transmits the second light flux Lf2 to guide the second light flux Lf2 to the second imaging element 522b.

[0109] The branch optical system Bs can be configured based on a combination of a dichroic mirror and a wavelength selection filter, for example, but the specific configuration of the branch optical system Bs is not limited. The branch optical system Bs can have an optical device that separates (disperses) incident light into a plurality of light fluxes based on wavelength, and, for example, light in a visible light wavelength band and light in an invisible light wavelength band in the incident light can be separated into separate light fluxes. Further, the branch optical system Bs can include an optical device that separates incident light into a plurality of light fluxes without being based on wavelength, and, for example, the incident light can be separated into a plurality of light fluxes having the same wavelength characteristics.

[0110] Note that, in the case where the branch optical system Bs separates incident light into a plurality of light fluxes based on wavelength, each light flux after separation can also include light of a wavelength band (i.e., an unintended wavelength band) different from a wavelength band of light expected to be included as a main light component in each light flux. For example, in the case where the branch optical system Bs separates the observation light Lf into a first light flux Lf1 of a visible light wavelength band and a second light flux Lf2 of an invisible light wavelength band, the second light flux Lf2 can include visible light corresponding to about 3% to 20% of the amount of light in the visible light wavelength band in the observation light Lf. Figure 3 In the illustrated example, in the case where the branch optical system Bs separates the observation light Lf into a first light flux Lf1 of a visible light wavelength band and a second light flux Lf2 of an invisible light wavelength band, the second light flux Lf2 can include visible light corresponding to about 3% to 20% of the amount of light in the visible light wavelength band in the observation light Lf.

[0111] Note that, in the case where a light flux after separation includes light of an unintended wavelength band (also referred to herein as “leak light”), the optical element 15 can include a color filter that partially, substantially, or completely removes the leak light from the light flux. For example, in the case where the light included in the separated light flux is weak fluorescent light, if the light flux includes leak light, the fluorescent light as the original light reception target can not be properly received by the corresponding imaging element (e.g., the second imaging element 522b). In this case, the leak light is partially, substantially, or completely removed from the light flux by the color filter, whereby the fluorescent light to be received is more properly received by the corresponding imaging element.

[0112] Further, in the case where the branch optical system Bs separates incident light into a plurality of light fluxes without being based on wavelength, the plurality of light fluxes after separation can have approximately equal amounts of light or unequal amounts of light. For example, in the case where the branch optical system Bs separates the observation light Lf into a first light flux Lf1 of a visible light wavelength band and a second light flux Lf2 of an invisible light wavelength band, the second light flux Lf2 can include an amount of light corresponding to about 50% to 100% of the amount of light in the visible light wavelength band in the observation light Lf. Figure 3In the illustrated example, the first light flux Lf1 and the second light flux Lf2 separated by the branching optical system Bs each can have an amount of light of about 50% of the amount of light of the observation light Lf, or can have different amounts of light from each other (for example, an amount-of-light difference of about ±10% between the first light flux Lf1 and the second light flux Lf2). For example, the branching optical system Bs can be designed so that the amount-of-light difference between the plurality of light fluxes is determined based on a sensitivity difference between the imaging elements that receive the separated light fluxes.

[0113] As an example, in a case where excitation is performed on the ICG applied to the observation target, the branching optical system Bs can also include a wavelength selection filter that transmits light of other wavelength bands while reflecting light on the shorter-wavelength side of 820 nm-870 nm, which is the fluorescent wavelength of the ICG.

[0114] Figure 4 is a diagram showing a schematic configuration of another example of an imaging system of the camera head 50.

[0115] Figure 4 The branching optical system Bs included in the optical element 15 illustrated includes a color separation prism PR based on a combination of a plurality of (three) prisms and a wavelength selection filter FL. The wavelength selection filter FL is disposed on a junction surface between a first prism located most upstream in the color separation prism PR and a second prism adjacent to the first prism.

[0116] Other configurations are similar to those of the camera head 50 illustrated in Figure 3 above.

[0117] A portion (first light flux Lf1) of the observation light Lf incident to the optical element 15 of the present example is further reflected after being reflected by the junction surface between the first prism and the second prism of the color separation prism PR, and is guided to the first imaging element 522a. On the other hand, at least a portion (second light flux Lf2) of the other light of the observation light Lf is transmitted through the optical element 15 and guided to the second imaging element 522b. Note that by disposing an anti-reflection coating (AR coating) on the junction surface between the second prism and the third prism of the color separation prism PR, reflection of light on the junction surface can be effectively suppressed. Furthermore, the color separation prism PR is not limited to the example illustrated in Figure 4 above, and can have any configuration. For example, a two-piece prism formed by combining two prisms (a first prism and a second prism) can be used as the color separation prism PR.

[0118] The above Figure 3 and Figure 4The camera head illustrated in FIG. 1 is a typical example of a two-plate imaging module that performs imaging using two imaging elements, but the camera head 50 can perform imaging using three or more imaging elements.

[0119] Figure 5 FIG. 1 is a diagram illustrating a schematic configuration of another example of an imaging system of the camera head 50.

[0120] Figure 5 The camera head 50 illustrated in FIG. 1 has a configuration similar to that of the camera head 50 illustrated in FIG. 1, but the first branch optical system Bs1 and the second branch optical system Bs2 are provided as the optical element 15, and the observation light Lf is split into the first light flux Lf1 to the third light flux Lf3. Figure 3

[0121] The observation light Lf that has passed through the excitation light cutoff filter FC is incident on the first branch optical system Bs1. The first branch optical system Bs1 reflects the first light flux Lf1 toward the first imaging element 522a while transmitting other light in the observation light Lf. The observation light Lf that has passed through the first branch optical system Bs1 is incident on the second branch optical system Bs2. The second branch optical system Bs2 reflects the second light flux Lf2 toward the second imaging element 522b and transmits the third light flux Lf3 as other light in the observation light Lf to guide toward the third imaging element 522c.

[0122] The first branch optical system Bs1 and the second branch optical system Bs2 can be configured based on a combination of a dichroic mirror and a wavelength selection filter, for example, but the specific configuration of the first branch optical system Bs1 and the second branch optical system Bs2 is not limited.

[0123] Figure 6 FIG. 1 is a diagram illustrating a schematic configuration of another example of an imaging system of the camera head 50.

[0124] Figure 6 The optical element 15 illustrated in FIG. 1 has a configuration similar to that of the optical element 15 illustrated in FIG. 1, but includes a color separation prism PR, a first wavelength selection filter FL1, and a second wavelength selection filter FL2 as the branch optical system Bs. The first wavelength selection filter FL1 is provided on a joint surface between a first prism located most upstream in the color separation prism PR and a second prism adjacent to the first prism. The second wavelength selection filter FL2 is provided on a joint surface between the second prism and a third prism adjacent to the second prism. Figure 4

[0125] ​​A portion of the observation light Lf incident on the optical element 15 of the present example is reflected at the junction between the first prism and the second prism of the color-separating prism PR, and then further reflected, as the first light flux Lf1, from the optical element 15 toward the first imaging element 522a. On the other hand, the other light of the observation light Lf transmits through the junction between the first prism and the second prism. Then, a portion of the observation light Lf is reflected at the junction between the second prism and the third prism, and emitted as the second light flux Lf2 from the optical element 15 toward the second imaging element 522b. On the other hand, the other light of the observation light Lf transmits through the junction between the second prism and the third prism, and emitted as the third light flux Lf3 from the optical element 15 toward the third imaging element 522c.

[0126] As described above, by using a dichroic mirror or a plurality of prisms as the optical element 15, it is possible to separate the observation light Lf into a plurality of light fluxes (including the first light flux Lf1 and the second light flux Lf2). Then, by appropriately selecting the transmission wavelength band and the like optical characteristics of the wavelength-selective filter FL, it is possible to cause the plurality of light fluxes separated from the observation light Lf to respectively include light of a desired wavelength band.

[0127] Specifically, the two-plate imaging module (see Figure 3 and Figure 4 ) is advantageous in reducing the size of the structure of the camera head 50 and reducing the cost. On the other hand, according to the three-plate imaging module (see Figure 5 and Figure 6 ), three types of light can be simultaneously received by the three imaging elements (the first imaging element 522a to the third imaging element 522c).

[0128] [Functional Configuration of Medical Observation System]

[0129] Next, an example of the functional configuration of the medical observation system 100 described above will be described.

[0130] Figure 7 is a block diagram showing an example of the configuration of the camera head 50 and the control device 90.

[0131] The camera head 50 includes a lens unit 51, an imaging section 52, and a communication section 53.

[0132] The lens unit 51 includes one or a plurality of lenses, condenses the observation light transmitted through the insertion device 20 (see Figure 1A ), and guides the observation light to the imaging section 52.

[0133] The imaging section 52 receives the observation light transmitted via the lens unit 51 and outputs a corresponding image signal. Figure 7 The imaging section 52 shown includes a light incident section 521, an imaging element 522, and a signal processing section 523.

[0134] Imaging element 522 is a photoelectric conversion element that receives observation light transmitted through light incident section 521 and generates an image signal under the control of control device 90 (especially control unit 94 described later). Imaging element 522 is a charge-coupled device (CCD) image sensor or complementary metal-oxide-semiconductor (CMOS) image sensor.

[0135] Exposure to the imaging element 522 can be controlled using any shutter method, including mechanical or electronic shutters. In each of the embodiments described later, a rolling shutter method is used, but another shutter method (e.g., a global shutter method) can be used.

[0136] exist Figures 3 to 6 In the example shown above, multiple imaging elements 522 are provided, but the imaging unit 52 may include a single imaging element 522. When the imaging unit 52 includes a single imaging element 522 and it is not necessary to separate the observation light into multiple luminous fluxes, an optical element for separating the observation light into multiple luminous fluxes (see [reference]) is used. Figures 3 to 6 The reference symbol “15” in the text is unnecessary.

[0137] As described later, by irradiating the target of observation with multiple lights of different wavelength bands at different times, a single imaging element 522 can appropriately receive multiple observation lights (e.g., reflected light from white light and fluorescence) caused by multiple lights. Furthermore, a single imaging element 522 capable of receiving multiple types of wavelength bands of light can be used. For example, an imaging element 522, also known as a direct image sensor, can be used that utilizes the vertical color separation characteristics of an imaging element (e.g., silicon) to receive multiple observation lights of different wavelength bands through each of multiple light-receiving layers arranged vertically in the imaging element. In this case, multiple luminous fluxes separated from the observation light through each of the multiple light-receiving layers of the imaging element 522 (specifically, multiple luminous fluxes of light of different wavelength bands) can also be received. As an example, a single imaging element 522, which includes multiple light-receiving layers capable of receiving visible light (e.g., red, green, and blue light) and one or more light-receiving layers capable of receiving fluorescence in invisible light wavelength bands (e.g., infrared or ultraviolet light), can receive both light flux including visible light as the primary light component and light flux including fluorescence as the primary light component.

[0138] When multiple imaging elements 522 are provided, two or more imaging elements 522 with different characteristics (e.g., resolution, sensitivity, pixel size, number of pixels, overall size, color filter, etc.) can be provided. Alternatively, two or more imaging elements 522 with the same characteristics can be provided.

[0139] The light-incident portion 521 is an optical system device that guides the observation light from the lens unit 51 to the light-receiving surface of the imaging element 522. For example, in a case where a plurality of imaging elements 522 are provided, the light-incident portion 521 includes the optical element 15 described above (see Figures 3 to 6 ), which divides the observation light into a plurality of light fluxes and guides the plurality of light fluxes to the plurality of imaging elements 522.

[0140] Note that, in a case where two or more imaging elements 522 having different physical sizes are provided, a lens (viewing angle adjustment lens) that optically magnifies or reduces an image to align the viewing angles with each other can be provided for two or one of the two or more imaging elements 522. Such a viewing angle adjustment lens can be provided as the light-incident portion 521 or can be provided as a part of the imaging element 522. By installing the viewing angle adjustment lens, an image having a uniform viewing angle can be acquired by the two or more imaging elements 522 having different sizes. Therefore, in generation of the superimposed image described later, it is not necessary to display a boundary line between a superimposed region and a non-superimposed region, to shield the non-superimposed region, and the like, and it is possible to efficiently use the pixel data of the imaging element 522.

[0141] The signal processing portion 523 performs signal processing (for example, automatic gain control (AGC) processing or analog-digital (AD) conversion processing) on the image signal generated by the imaging element 522 under the control of the control device 90 (the control portion 94).

[0142] The communication portion 53 communicates with the control device 90 (specifically, the communication portion 91) via the transmission cable 80 under the control of the control device 90 (specifically, the control portion 94). The image signal (digital signal) output from the imaging portion 52 is transmitted from the communication portion 53 to the control device 90 (specifically, the communication portion 91) via the transmission cable 80. The communication standard between the communication portion 53 of the camera head 50 and the communication portion 91 of the control device 90 is not limited, and the communication portion 53 and the communication portion 91 can be configured as a high-speed serial interface.

[0143] The control device 90 includes the communication portion 91, the memory 92, the image generation portion 93, the control portion 94, the input portion 95, the output portion 96, and the storage portion 97.

[0144] The communication portion 91 transmits the image signal transmitted from the camera head 50 to the image generation portion 93 via the transmission cable 80 under the control of the control portion 94.

[0145] The image generation portion 93 performs various types of image processing under the control of the control portion 94 and generates an image based on the image signal from the imaging portion 52. Figure 7The illustrated image generation section 93 includes a memory controller 930, an image processing section 931, an overlay image generation section 934, and a display control section 935.

[0146] The memory controller 930 writes and reads data to and from the memory 92. For example, the memory controller 930 writes, as image data, an image signal transmitted from the camera head 50 via the communication section 91 to the memory 92. Then, the memory controller 930 reads the image data from the memory 92 as necessary and supplies the image data to the image processing section 931, the overlay image generation section 934, and / or the display control section 935.

[0147] Note that the memory 92 can be configured by, for example, a volatile memory or a non-volatile memory, and can function as a device capable of temporarily storing various data. Data capable of being stored in the memory 92 is not limited. Thus, the memory controller 930 can write and read, to and from the memory 92, image data and other data transmitted from the image processing section 931, the overlay image generation section 934, and / or the display control section 935.

[0148] The image processing section 931 performs image processing on an image signal transmitted from the camera head 50 and generates a corresponding image (captured image). The image processing section 931 can perform arbitrary image processing. For example, the image processing section 931 can perform one or more of AGC processing, optical black subtraction processing, white balance adjustment processing, demosaicing processing, grayscale correction processing, image (video) signal level adjustment processing, color correction processing, gamma correction processing, and fluorescent image signal processing.

[0149] The specific configuration of the image processing section 931 is not limited, and the image processing section 931 can include a single processing section regardless of the number of imaging elements 522, or can include a plurality of processing sections corresponding to each of the plurality of imaging elements 522. In a case where a plurality of imaging elements 522 is assigned to one processing section of the image processing section 931, a plurality of corresponding images can be generated by sequentially processing a plurality of image signals from the plurality of imaging elements 522 by one processing section.

[0150] Further, for example, in a case where two imaging elements 522 are provided, the image processing section 931 can include a first processing section that generates an image based on an image signal from one imaging element 522 and a second processing section that generates an image based on an image signal from the other imaging element 522. In a case where the image processing section 931 includes a plurality of processing sections assigned exclusively to each of the plurality of imaging elements 522, image generation processing based on image signals from the plurality of imaging elements 522 can be performed simultaneously in parallel.

[0151] The superimposition image generation section 934 combines a plurality of images to generate a superimposition image. The type of the plurality of images that are the basis of the superimposition image generated by the superimposition image generation section 934 and the specific combining method are not limited.

[0152] For example, the superimposition image can be generated by combining a captured image based on reflected light from an observation target irradiated with white light (broadband light) (also referred to as a "normal light captured image") and a captured image based on fluorescence from an observation target irradiated with excitation light (narrowband light) (also referred to as a "fluorescence captured image"). Alternatively, the superimposition image can be generated by combining captured images based on a plurality of fluorescences having different wavelength bands from a common observation target.

[0153] The superimposition image generation section 934 can perform the combining process on the entire area of each of the plurality of images that are the basis of the superimposition image, or can perform the combining process on only a partial area.

[0154] In a case where the total number of pixels (size) of the plurality of images that are the basis of the superimposition image is the same and the imaging ranges (including the observation target) included in the plurality of images completely coincide with each other, the superimposition image can be generated by performing the combining process on the entire area of the plurality of images without performing the relative size adjustment and the positional adjustment between the plurality of images. In addition, in a case where the total number of pixels of the plurality of images that are the basis of the superimposition image is the same as each other, but the imaging ranges (including the observation target) included in the plurality of images do not completely coincide with each other, the relative positional adjustment or the size adjustment between the plurality of images is performed, and the combining process is performed on the images of the imaging range common between the plurality of images (for example, a part of the common observation target), and thus the superimposition image can be generated. Furthermore, in a case where the plurality of images that are the basis of the superimposition image include images of two or more imaging elements having different angles of view and total pixel numbers from each other, the superimposition image generation section 934 can perform the combining process for generating the superimposition image after adjusting the angles of view and the total pixel numbers of the images of the two or more imaging elements using an arbitrary image processing technique such as digital zoom.

[0155] As an example, a case where a superimposition image of a first image (for example, a normal light captured image) and a second image (for example, a fluorescence captured image related to fluorescence emitted by a single type of fluorescent substance (for example, a fluorescent agent)) is generated is assumed. In this case, if the total number of pixels and each of the imaging ranges are the same between the first image and the second image, the superimposition image can be generated by superimposing and combining the first image and the second image with each other in the entire area without performing the size adjustment and the positional adjustment. In a case where the total number of pixels is different between the first image and the second image, the size adjustment (scaling) of one or both of the first image and the second image is performed, and the first image and the second image after the size adjustment are combined to be superimposed with each other, and thus the superimposition image can be generated.

[0156] Note that, as with the superimposed image of the first image and the second image described above, a superimposed image of the first image (e.g., a normal light capture image), the second image (e.g., a fluorescent light capture image related to fluorescent light emitted from the first fluorescent substance (e.g., a first fluorescent agent)), and the third image (e.g., a fluorescent light capture image related to fluorescent light emitted from the second fluorescent substance (e.g., a second fluorescent agent)) can also be generated. That is, in a case where the total number of pixels and the imaging range are the same in the first image to the third image, the superimposed image can be generated by superimposing and combining the first image to the third image in the entire area without performing size adjustment and position adjustment. In addition, in a case where the total number of pixels is different between the first image to the third image, size adjustment (scaling) of one or more of the first image to the third image is performed, and the first image to the third image after the size adjustment are combined so as to be superimposed on each other, whereby the superimposed image can be generated.

[0157] The superimposed image generation section 934 can automatically generate a superimposed image of a plurality of mutually related images under the control of the control section 94, or can generate a superimposed image using a plurality of images specified by a user as original images. The user can specify a plurality of original images via the input section 95, and the control section 94 can control the superimposed image generation section 934 to generate a superimposed image from the plurality of original images specified via the input section 95.

[0158] Further, the superimposed image generation section 934 can change the color of the object including the observation target in the superimposed image under the control of the control section 94. For example, the superimposed image generation section 934 can change the fluorescent portion in the superimposed image to a color having high visibility. The "color having high visibility" mentioned here is a color that is easily recognized by a user who views the superimposed image, and can be, for example, a color that is not initially displayed for the observation target or a color that is not initially displayed much (e.g., light yellow green), or can be a color that is not used in other portions of the superimposed image.

[0159] For example, in a case where the superimposed image is generated from the fluorescence capture image and the normal light capture image based on the luminance signal information not having the color information, the fluorescence capture image can also be combined with the normal light capture image as an image not having the color information, or the fluorescence capture image can also be combined with the normal light capture image after being changed to a specific color (for example, a color with high visibility). Further, in a case where the fluorescence capture image is a color image having color information, the fluorescence capture image can be combined with the normal light capture image by changing the color information to the luminance signal information. In addition, in order to easily observe the fluorescence capture image superimposed on the normal light capture image, the normal light capture image can also be changed to a monochrome image based on the luminance signal information not having the color information, and the fluorescence capture image can be changed to a specific color (for example, a color with high visibility) in the superimposed image.

[0160] The display control section 935 generates an output image under the control of the control section 94. The display control section 935 can generate an output image based on the capture image generated by the image processing section 931 and / or the superimposed image generated by the superimposed image generation section 934. The output image generated by the display control section 935 can include only a single image of the capture image and the superimposed image, or can include a plurality of images.

[0161] In a case where the output image includes a plurality of images, the arrangement pattern of the plurality of images in the output image is not limited. In general, a picture-in-picture (PiP) (see the later-described Fig. 12) in which another image is arranged in an overlaid manner with respect to a certain image, or a picture-by-picture (PbP) format in which a plurality of images are arranged, can be adopted as the output image. Figure 11 ) or a picture-by-picture (PbP) format in which a plurality of images are arranged, can be adopted as the output image. Therefore, the display control section 935 can produce an output image in a PiP format in which one or a plurality of relevant capture images are reduced and arranged in a partial region of the superimposed image.

[0162] Further, the output image generated by the display control section 935 can be a still image or a moving image (video).

[0163] The output image generated by the display control section 935 is transmitted to the display device 70 and displayed on the display of the display device 70. In a case where a plurality of display devices 70 are connected to the control device 90, the display control section 935 generates an output image corresponding to the characteristics of each of the plurality of display devices 70 and outputs the output image to each of the plurality of display devices 70. For example, in a case where two or more display devices 70 having screen resolutions (i.e., display total pixels) different from each other are connected to the control device 90, the display control section 935 can generate a plurality of types of output images having pixel numbers corresponding to each of the screen resolutions of the two or more display devices 70. Therefore, the output image having an optimized size is displayed on each of the two or more display devices 70.

[0164] The display control section 935 can automatically generate an output image under the control of the control section 94, or can generate an output image according to a user's designation. The user can designate one or more images included in the output image via the input section 95, and the control section 94 can control the display control section 935 to generate an output image according to the one or more images designated via the input section 95, and transmit the output image to the display device 70. As a result, the user can determine an output image to be displayed on the display device 70 based on his / her own intention, and can switch the output image as needed.

[0165] The control section 94 controls the light source device 10, the camera head 50, and the display device 70, and also controls each part (the communication section 91, the image generation section 93, the input section 95, the output section 96, the storage section 97, and the like) of the control device 90. The control target of the control section 94 is not limited. For example, in each of the embodiments described later, under the control of the control section 94, light emission in the light source device 10, reading of image data from the imaging element 522, and image processing in the image generation section 93 are performed.

[0166] For example, in a case where the sensitivity of the imaging element 522 is insufficient, the control section 94 can control the imaging element 522 to reduce the frame rate of the image signal output from the imaging element 522, thereby increasing the exposure time in the imaging element 522. Further, the control section 94 can control the image generation section 93 (specifically, the image processing section 931) to add data (pixel values) of the pixels of two or more imaging elements in the process of generating a captured image.

[0167] On the other hand, in a case where the output frame rate of the imaging element 522 is increased, the control section 94 can also control the imaging element 522 and the signal processing section 523 to perform thinning reading and area designation reading of pixel data. In this case, data (pixel values) of only a part of the plurality of pixels included in the imaging element 522 are used for image generation.

[0168] The input section 95 functions as an instruction receiving section that receives an instruction from a user, receives an instruction from a user under the control of the control section 94, and transmits the instruction to the control section 94. The input section 95 can take any form, and can be configured as a device (for example, a touch panel, an operation button, and the like) that is directly operated by a user.

[0169] Alternatively, the input section 95 can be configured as a connection section to which a device operated by a user (for example, a mouse, a keyboard, or a portable device) is connected in a wired or wireless manner. For example, an instruction inputted by a user via the operation section of the light source device 10, the operation section of the camera head 50, the operation section of the insertion device 20, and the operation section of the display device 70 can be transmitted to the control section 94 via the input section 95 of the control device 90.

[0170] The output section 96 outputs various information according to the control of the control section 94. The output section 96 can take any form, and can be provided as, for example, a speaker, a printer, a communication device, and / or an application program.

[0171] The storage section 97 writes and reads various data by the control section 94, and stores, for example, a program executed by the control section 94, information required for the processing of the control section 94, and the like.

[0172] [Image display example]

[0173] Next, an image display example in the display device 70 will be described.

[0174] Hereinafter, a case where biological tissues having a first recognition target and a second recognition target are captured and displayed as an image as an observation target will be exemplified. Here, the recognition target is, for example, a lesion, a blood vessel, a nerve, or the like. Specifically, the first recognition target includes a first substance that is excited by the first narrow-band light and emits fluorescence, but does not include a second substance that is excited by the second narrow-band light and emits fluorescence. On the other hand, the second recognition target does not include the first substance but includes the second substance.

[0175] Figure 8 An example of an output image 210 displayed on the display device 70 is shown. Figure 8 The output image 210 shown in (a) is a captured image based on reflected light of the wide-band light (specifically, white light) emitted to the observation target.

[0176] The first substance in the first recognition target and the second substance in the second recognition target are not excited or have a weak degree of excitation even when irradiated with white light, and thus do not emit fluorescence or emit only weak fluorescence. Therefore, in the output image 210 shown in (a), it is less likely to recognize the first recognition target and the second recognition target that appear as the first recognition target image 213 and the second recognition target image 214, compared to the observation target (for example, the outline) that appears as the clear observation target image 211. Figure 8 In the output image 210 shown in (a), it is less likely to recognize the first recognition target and the second recognition target that appear as the first recognition target image 213 and the second recognition target image 214, compared to the observation target (for example, the outline) that appears as the clear observation target image 211.

[0177] Figure 9 Another example of an output image 210 displayed on the display device 70 is shown. Figure 9The output image 210 shown is a superimposed image based on a captured image of reflected light of broadband light (particularly white light) irradiated to the observation target and a captured image based on fluorescence from the observation target irradiated with the first narrow-band light (excitation light).

[0178] The first substance in the first recognition target is excited by irradiation with the first narrow-band light and emits strong fluorescence. On the other hand, even in the case where the second substance in the second recognition target is irradiated with white light and the first narrow-band light, the second substance is not excited or is weakly excited, and thus the second substance does not emit fluorescence or emits only weak fluorescence. Therefore, in the output image 210 shown in Figure 9 In the output image 210 shown, the second recognition target appearing as the second recognition target image 214 is less likely to be recognized than the observation target appearing as the clear observation target image 211 and the first recognition target appearing as the first recognition target image 213.

[0179] Therefore, in the output image 210 shown in Figure 9 In the output image 210 shown, the user can clearly view the observation target image 211 and the first recognition target image 213 at the same time, but it is difficult or impossible to clearly view the second recognition target image 214.

[0180] Figure 10 Another example of the output image displayed on the display device 70 is shown. Figure 10 The output image 210 shown is a superimposed image based on a captured image of reflected light of broadband light (particularly white light) irradiated to the observation target, a captured image based on fluorescence from the observation target irradiated with the first narrow-band light (excitation light), and a captured image based on fluorescence from the observation target irradiated with the second narrow-band light (excitation light).

[0181] The first substance in the first recognition target is excited by irradiation with the first narrow-band light and emits strong fluorescence, and the second substance in the second recognition target is excited by irradiation with the second narrow-band light and emits strong fluorescence. Therefore, in the output image 210 shown in Figure 10 In the output image 210 shown in, the observation target, the first recognition target, and the second recognition target are shown as the clear observation target image 211, the clear first recognition target image 213, and the clear second recognition target image 214, respectively. Therefore, the user can visually recognize the observation target image 211, the first recognition target image 213, and the second recognition target image 214 clearly at the same time in the output image 210 shown in Figure 10 In the output image 210 shown, the user can clearly view the observation target image 211 and the first recognition target image 213 at the same time, but it is difficult or impossible to clearly view the second recognition target image 214.

[0182] Figure 11 Another example of the output image displayed on the display device 70 is shown. Figure 11The output image 210 shown in FIG. 6 is displayed in a PiP format, and includes a main image 620 and one or more reduced display images (in this example, a first reduced display image 621 and a second reduced display image 622) that occupy a partial region of the main image 620.

[0183] Figure 11 The main image 620 shown in FIG. 6 is a captured image based on reflected light of broadband light (specifically, white light) emitted to the observation target (see Figure 8 ). The first reduced display image 621 is a reduced image of a superimposed image based on a captured image of reflected light of broadband light (specifically, white light) that irradiates the observation target and a captured image of fluorescence from the observation target that is irradiated with first narrowband light (excitation light) (see Figure 9 ). The second reduced display image 622 is a reduced image of a superimposed image based on a captured image of reflected light of broadband light (specifically, white light) that irradiates the observation target and a captured image of fluorescence from the observation target that is irradiated with second narrowband light (excitation light).

[0184] Note that, under the control of the control device 90 (specifically, the control section 94 (see Figure 7 )), the image displayed as the output image 210 on the display device 70 (see Figures 8 to 11 ) can be changed based on an instruction from user input via the input section 95.

[0185] For example, the control section 94 can control the display control section 935 to change the image of the main image 620 and the reduced display images 621 and 622 that are displayed as the output image 210 in a PiP format based on an instruction from user input via the input section 95. Further, the control section 94 can control the display control section 935 to interchange the image displayed as the main image 620 with the image displayed as the reduced display images 621 and 622 and interchange the display images between the reduced display images 621 and 622 based on an instruction from user input via the input section 95.

[0186] Further, the control device 90 (specifically, the control section 94) can control the display control section 935 to switch the display format of the output image 210 between a single image display format (see Figures 8 to 10 ) and a multiple image display format (see Figure 11 ).

[0187] The user can change the display format of the output image 210 (see Figures 8 to 11The state and characteristics of the observed target can be determined. Specifically, users can accurately and easily determine the state and characteristics of the observed target by simultaneously or switching and confirming multiple types of images with different characteristics of the observation light associated with the same observed target. By displaying a superimposed image obtained by overlaying one or more fluorescence images on a broadband light image on a display device 70 in this way, users can capture the entire affected area to be observed based on the broadband light image in the superimposed image, while confirming the location of blood vessels, lesions, etc. to be identified during surgery based on the fluorescence image, thus supporting the smooth progress of the surgery.

[0188] [Example of observation method]

[0189] Next, a typical implementation of a method (medical observation method) for observing a target using the medical observation system 100 will be described.

[0190] The following first to fifth embodiments are two-plate imaging modules in which the imaging unit 52 of the camera head 50 includes two imaging elements 522 (see Figure 3 and Figure 4 A typical example of this is the use of a three-plate imaging module in which the imaging unit 52 of the camera head 50 includes three imaging elements 522 (see [reference]). Figure 5 and 6 A typical example of the situation.

[0191] The representative observation modes performed in each embodiment will be described below. Additionally, in each embodiment, the medical observation system 100 is also capable of performing other observation modes not mentioned below.

[0192] The observation mode can be switched based on instructions from a user, such as a surgical operator of the medical observation system 100. When the user inputs an instruction indicating the desired observation mode via the input section 95 of the control device 90, the instruction is sent from the input section 95 to the control unit 94. The control unit 94 controls each part of the light source device 10, the camera head 50, and the control device 90 based on the instructions input by the user via the input section 95, thereby executing the desired observation mode.

[0193] In the following embodiments, the broadband light emitted from the broadband light source 11 is white light, and the first wavelength band as the wavelength band of the broadband light includes a visible light wavelength band. Further, the first fluorescent light emitted from the first substance excited by the first narrow-band light from the first narrow-band light source 12 is visible light (specifically, visible light having a wavelength band superimposed on the wavelength band of the broadband light (white light)). Further, the second fluorescent light and the third fluorescent light emitted from the second substance and the third substance excited by the second narrow-band light and the third narrow-band light from the second narrow-band light source 13 and the third narrow-band light source 14 are non-visible light (for example, infrared light) included in a non-visible light wavelength band. The wavelength band of the second fluorescent light and the third fluorescent light is included in the non-visible light wavelength band and is not superimposed on the wavelength band of the broadband light (white light) and the first fluorescent light. Note that the infrared light referred to here includes near-infrared light, mid-infrared light, and far-infrared light, and is light (electromagnetic waves) in a wavelength band of about 700 nm to 1000 μm.

[0194] The broadband light (white light) emitted from the broadband light source 11 serves as illumination light for bright illumination of the observation target. On the other hand, the first narrow-band light to the third narrow-band light are used as excitation light for the fluorescent substances (the first substance to the third substance). When the observation target is irradiated with the broadband light (white light), at least a part of the broadband light is reflected as broadband reflected light. In addition, in a case where the observation target is irradiated with the excitation light (the first narrow-band light to the third narrow-band light), the observation target emits the corresponding fluorescent light at a portion including the corresponding fluorescent substance and does not emit the corresponding fluorescent light at a portion not including the corresponding fluorescent substance.

[0195] Note that the specific wavelength bands of the broadband light and the first fluorescent light to the third fluorescent light are not limited to the above-described examples, and the embodiments described below can be appropriately applied even in a case where the broadband light and the first fluorescent light to the third fluorescent light are light of other wavelength bands.

[0196] [First Embodiment]

[0197] Figure 12 is a diagram for explaining the types of light incident on the imaging elements (the first imaging element 522a and the second imaging element 522b) according to the first embodiment.

[0198] The camera head 50 (specifically, the imaging section 52) of the present embodiment includes a two-plate imaging module (see Figure 3 and Figure 4 ), and includes the first imaging element 522a having the color filter CF and the second imaging element 522b not having the color filter CF.

[0199] For example, the resolution of the first imaging element 522a can be higher than the resolution of the second imaging element 522b, and the sensitivity of the second imaging element 522b can be higher than the sensitivity of the first imaging element 522a. However, the resolution and the sensitivity of the first imaging element 522a and the second imaging element 522b are not limited thereto, and the relative relationship between the resolution and the sensitivity between the first imaging element 522a and the second imaging element 522b is not limited thereto.

[0200] The color filter CF can have an arbitrary color filter and an arbitrary filter array, as long as light in a desired wavelength band can be incident on the corresponding imaging element, and can include a primary color filter (RGB filter) or a complementary color filter (CMYG filter). The color filter CF provided in the first imaging element 522a of the present embodiment transmits the wideband reflected light Lw1 and the first fluorescent light Lw2 (as described later) received by the first imaging element 522a, but can or can not transmit light (for example, the second fluorescent light Lw3) in a wavelength band other than the wideband reflected light Lw1 and the first fluorescent light Lw2. The color filter CF can be provided for all the pixels of the first imaging element 522a, or can be provided for some of the pixels of the first imaging element 522a.

[0201] Note that the second imaging element 522b of the present example does not include the color filter CF, but can include the color filter CF capable of transmitting the second fluorescent light Lw3 described later. For example, in the case where the second fluorescent light Lw3 is infrared light, an R color filter capable of transmitting not only red light in the visible light region but also infrared light (specifically, the second fluorescent light Lw3) can be provided in the second imaging element 522b. As described above, the second imaging element 522b can or can not include the color filter CF, but in the case where the color filter CF is not included, a captured image having higher light-receiving sensitivity can be obtained. For example, in the case where the first imaging element 522a includes an RGB color filter as the color filter CF, the second imaging element 522b can also include an RGB color filter similar to the first imaging element 522a.

[0202] The light source device 10 (see Figure 1A ) emits light from at least one of the wideband light source 11, the first narrowband light source 12, or the second narrowband light source 13, and can irradiate the observation target S with at least one of the wideband light, the first narrowband light, and the second narrowband light.

[0203] Therefore, the observation light Lf from the observation target S can include a wideband reflection light Lwl that is reflection light of the wideband light, a first fluorescent light Lw2 emitted from a first substance excited by the first narrowband light, and a second fluorescent light Lw3 emitted from a second substance excited by the second narrowband light. Note that the wideband reflection light Lwl and the first fluorescent light Lw2 are lights included in the first wavelength band, and the second fluorescent light Lw3 is a light included in a second wavelength band outside the first wavelength band.

[0204] The observation light Lf incident on the optical element 15 is split by the optical element 15 into a first light flux Lfl and a second light flux Lf2. The optical element 15 of the present embodiment guides light included in the first wavelength band to the first imaging element 522a as the first light flux Lfl, and guides light included in the second wavelength band to the second imaging element 522b as the second light flux Lf2.

[0205] As described above, in the present embodiment, the first light flux Lfl in which light in the wavelength band of the second fluorescent light Lw3 is partially, substantially, or completely suppressed in the observation light Lf is guided to the first imaging element 522a. That is, light including at least the wideband reflection light Lwl and the first fluorescent light Lw2 is guided to the first imaging element 522a as the first light flux Lfl. Further, in the observation light Lf, the second light flux Lf2 in which light in the first wavelength band is partially, substantially, or completely suppressed by the optical element 15 is guided to the second imaging element 522b. That is, light including at least the second fluorescent light Lw3 included in the second wavelength band is guided to the second imaging element 522b as the second light flux Lf2.

[0206] The medical observation system 100 of the present embodiment having the above-described structure can acquire various captured images of the observation target S according to the following observation modes (first mode to third mode).

[0207] <First Mode>

[0208] The first mode of the present embodiment is an observation mode in which the wideband light and the first narrowband light are irradiated to the observation target S to acquire a captured image based on the wideband reflection light Lwl and the first fluorescent light Lw2 from the observation target S.

[0209] The control device 90 (control section 94 (see Figure 7 )) controls the light source device 10 (wideband light source 11 and first narrowband light source 12 (see Figure 1A )) to emit the wideband light and the first narrowband light from the light source device 10 in a time-division manner, and to emit the wideband light and the first narrowband light to the observation target S in a time-division manner. That is, the light source device 10 sequentially emits the wideband light and the first narrowband light, and sequentially irradiates the wideband light and the first narrowband light to the observation target S.

[0210] The light emission duration of each pulse in time-division light emission (pulsed light emission) is not limited. The light emission duration can be the same or different between pulses emitted from one light source, and the light emission duration can be the same or different between pulses emitted from a plurality of light sources. Furthermore, the irradiation interval as the time interval between a certain pulse and the next pulse is not limited. The irradiation interval can be the same or different between pulses emitted from one light source, and the irradiation interval can be the same or different between pulses emitted from a plurality of light sources.

[0211] Then, the optical element 15 sequentially guides the first light flux Lfl including the wideband reflected light Lwl from the observation target S irradiated with the wideband light and the first light flux Lfl including the first fluorescent light Lw2 from the observation target S irradiated with the first narrowband light to the first imaging element 522a. Accordingly, the first imaging element 522a sequentially receives the first light flux Lfl including the wideband reflected light Lwl and the first light flux Lfl including the first fluorescent light Lw2.

[0212] Then, the first imaging element 522a outputs an image signal based on the wideband reflected light Lwl and an image signal based on the first fluorescent light Lw2 sequentially and repeatedly under the control of the control device 90 (control section 94).

[0213] Then, the image generation section 93 (specifically, the image processing section 931 (see Figure 7 ) generates a captured image (high-resolution color image) of the observation target S based on the wideband reflected light Lwl from the image signal based on the wideband reflected light Lwl output from the first imaging element 522a. Furthermore, the image generation section 93 (image processing section 931) generates a captured image (high-resolution color image) of the observation target S based on the first fluorescent light Lw2 from the image signal based on the first fluorescent light Lw2 output from the first imaging element 522a. The "high-resolution color image" referred to here is a color image acquired by a high-resolution imaging element, and it is not necessarily required that the output image sent from the high-resolution imaging element to the subsequent stage has the same high resolution as the "color image acquired by a high-resolution imaging element".

[0214] Figure 13 An example of a timing chart showing the light emission of the light source and the exposure of the imaging element in the first mode of the first embodiment is shown.

[0215] Figure 13 (a) of FIG. 12 shows the exposure state of the first imaging element 522a, and the vertical axis represents the horizontal line of the first imaging element 522a, and the horizontal axis represents time. In Figure 13 In (a) of FIG. 12, the uppermost line represents the uppermost horizontal line (i.e., the first row), and the lowermost line represents the lowermost horizontal line (i.e., the last row).

[0216] The line (diagonal line) indicated by reference sign "R1" indicates a pixel data read start time with respect to each horizontal line of each image frame. The "wideband light image frame" between the lines R1 is an image frame for receiving (exposure) of the wideband reflected light Lwl from the observation target S. The "first fluorescent light image frame" between the lines R1 is an image frame for receiving (exposure) of the first fluorescent light Lw2 from the observation target S.

[0217] Figure 13 (b) of FIG. 1 shows the emission timing of the wideband light in the wideband light source 11, and Figure 13 (c) of FIG. 1 shows the emission timing of the first narrowband light in the first narrowband light source 12. Note that, after the light emission, the light emitted from the light source apparatus 10 reaches the observation target S instantaneously. Therefore, the timing at which the wideband light from the wideband light source 11 is emitted to the observation target S and the timing at which the wideband reflected light Lwl from the observation target S is received by the first imaging element 522a are substantially the same as the timing at which the wideband light is emitted from the wideband light source 11.

[0218] In this mode, as described above, the light emission in the light source apparatus 10 and the irradiation of the observation target S with the wideband light and the first narrowband light are performed in a time-division manner. Further, the exposure (light reception) in the first imaging element 522a and the reading of the image data (pixel values) with respect to the wideband reflected light Lwl and the first fluorescent light Lw2 from the observation target S from the first imaging element 522a are sequentially performed. Therefore, the control apparatus 90 (control section 94) performs control so that the timing of the time-division light emission of the light source apparatus 10 corresponds to the timing of the reading of the image data from the first imaging element 522a.

[0219] Specifically, based on the timing determined by the common synchronization signal from the control section 94, the time-division light emission of the wideband light and the first narrowband light in the wideband light source 11 and the first narrowband light source 12 is performed, and the exposure and the reading of the image data in the first imaging element 522a are performed. More specifically, the wideband light and the first narrowband light are sequentially emitted without being superimposed on each other so that the first imaging element 522a is not simultaneously exposed to the wideband reflected light Lwl and the first fluorescent light Lw2.

[0220] Then, the image data is read from the first imaging element 522a so that the wideband light image frame exposed by the wideband reflected light Lwl and the first fluorescent light image frame exposed by the first fluorescent light Lw2 are alternately output from the first imaging element 522a.

[0221] In the present example, exposure and reading of image data in the first imaging element 522a is performed based on a global shutter method. That is, when imaging a certain image frame, exposure is started sequentially row by row from the first row to the last row of the plurality of pixels of the first imaging element 522a. Then, after the elapse of the exposure time, pixel data is output sequentially row by row from the first row to the last row of the plurality of pixels. The exposure time of each image frame meaning the period of time from the start to the end of accumulation of electric charges in each pixel is not limited, but is usually set to 1 / 60 seconds or 1 / 50 seconds in many cases.

[0222] In Figure 13 In the example shown, emission of the wideband light and the first narrowband light is started and terminated while image data is not being read from the first imaging element 522a. Therefore, substantial incidence of the wideband reflected light Lwl and the first fluorescent light Lw2 on the first imaging element 522a is started and terminated while image data is not being read from the first imaging element 522a. In this case, in the wideband light image frame of the first imaging element 522a, incidence of the first fluorescent light Lw2 from the observation target S irradiated with the first narrowband light to the first imaging element 522a can be suppressed. Further, in the first fluorescent light image frame of the first imaging element 522a, incidence of the wideband reflected light Lwl from the observation target S irradiated with the wideband light to the first imaging element 522a can be suppressed.

[0223] Note that the start timing and the end timing of light emission of the wideband light and the first narrowband light are not limited to the example shown in Figure 13 and can be set to any timing. For example, light emission of one or both of the wideband light and the first narrowband light can be started or terminated while image data is being read from the first imaging element 522a (see "Rl" in Figure 13 For example, in a case where the intensity of fluorescent light as a light reception target in the first fluorescent light image frame is weak (i.e., in a case where the amount of fluorescent light emission is small), the first narrowband light can be emitted from the first narrowband light source 12 while image data of the wideband light image frame is being read. In this case, the exposure time of fluorescent light in the first fluorescent light image frame can be extended, which is advantageous for obtaining image data of a bright first fluorescent light image frame. Specifically, in a case where the first fluorescent light Lw2 has an amount of light sufficiently smaller than the wideband reflected light Lwl and the influence of the first fluorescent light Lw2 on the wideband light image frame is sufficiently smaller than the influence of the wideband reflected light Lwl on the wideband light image frame, the first narrowband light source 12 can continuously emit the first narrowband light. The "continuous light emission" referred to here means continuous light emission.

[0224] In this way, the first imaging element 522a alternately and repeatedly outputs an image signal of a wideband light image frame (i.e., an image signal based on the wideband reflected light Lwl) and an image signal of a first fluorescent light image frame (i.e., an image signal based on the first fluorescent light Lw2). Then, based on the image signal of the wideband light image frame, a normal light captured image of the observation target S as a reflected image of the wideband light (white light) is generated. Further, based on the image signal of the first fluorescent light image frame, a first fluorescent light captured image as a captured image based on the first fluorescent light Lw2 of the observation target S is generated.

[0225] As described above, in this mode, within a common time frame, a normal light captured image as a reflected image of visible light (white light) and a first fluorescent light captured image that emphasizes the first substance of the observation target S, i.e., emits fluorescent light from the first substance in the observation target S excited by narrowband light, are acquired. Therefore, the user can compare and observe the normal light captured image and the first fluorescent light captured image of the observation target S and observe a combined image (superimposed image) formed by these images via the display device 70 (see FIG. 6). Figure 1A ).

[0226] <Second Mode>

[0227] The second mode of the present embodiment is an observation mode in which the wideband light and the second narrowband light are irradiated to the observation target S to acquire captured images based on the wideband reflected light Lwl and the second fluorescent light Lw3 from the observation target S.

[0228] The control device 90 (control section 94) controls the light source device 10 (wideband light source 11 and second narrowband light source 13), continuously emits the wideband light and the second narrowband light from the light source device 10, and continuously emits the wideband light and the second narrowband light to the observation target S.

[0229] Then, the optical element 15 continuously guides the first light flux Lfl including the wideband reflected light Lwl from the observation target S irradiated with the wideband light to the first imaging element 522a. Also, the optical element 15 continuously guides the second light flux Lf2 including the second fluorescent light Lw3 from the observation target S irradiated with the second narrowband light to the second imaging element 522b.

[0230] As a result, the first imaging element 522a continuously receives the first light flux Lfl including the wideband reflected light Lwl, and the second imaging element 522b continuously receives the second light flux Lf2 including the second fluorescent light Lw3. Then, under the control of the control device 90 (control section 94), the first imaging element 522a continuously and repeatedly outputs an image signal based on the wideband reflected light Lwl, and the second imaging element 522b continuously and repeatedly outputs an image signal based on the second fluorescent light Lw3.

[0231] Then, the image generation section 93 (the image processing section 931) generates a captured image (a high-resolution color image) of the observation target S based on the wideband reflected light Lw1 from the image signal based on the wideband reflected light Lw1 output from the first imaging element 522a. Further, the image generation section 93 (the image processing section 931) generates a captured image (a high-sensitivity monochrome image) of the observation target S based on the second fluorescent light Lw3 from the image signal based on the second fluorescent light Lw3 output from the second imaging element 522b. The "high-resolution color image" mentioned here is a color image acquired by a high-resolution imaging element, and the "high-sensitivity monochrome image" is a monochrome image acquired by a high-sensitivity imaging element.

[0232] Figure 14 An example of a timing chart of light source emission and imaging element exposure in the second mode of the first embodiment is shown.

[0233] Figure 14 (a) of FIG. 6A indicates the exposure state of the first imaging element 522a, and (c) indicates the exposure state of the second imaging element 522b. In Figure 14 In (a) and (c) of FIG. 6A, the vertical axis indicates the horizontal line of the first imaging element 522a and the second imaging element 522b, the horizontal axis indicates time, and the line R1 indicates the pixel data read start timing for each horizontal line with respect to each image frame. The "wideband light image frame" between the lines R1 is an image frame for receiving (exposure) of the wideband reflected light Lw1 from the observation target S, and the "second fluorescent light image frame" between the lines R1 is an image frame for receiving (exposure) of the second fluorescent light Lw3 from the observation target S. Figure 14 (b) of FIG. 6B shows the light emission timing of the wideband light in the wideband light source 11, and Figure 14 (d) of FIG. 6D shows the light emission timing of the second narrowband light in the second narrowband light source 13.

[0234] In this mode, as described above, the emission in the light source apparatus 10 and the irradiation of the wideband light and the second narrowband light to the observation target S are continuously performed. Then, the exposure (light reception) in the first imaging element 522a with respect to the wideband reflected light Lw1 from the observation target S is continuously performed. Further, the exposure (light reception) in the second imaging element 522b with respect to the second fluorescent light Lw3 from the observation target S is continuously performed.

[0235] Therefore, at any time when the wideband light and the second narrowband light are emitted from the light source apparatus 10, the reading of the image data from the first imaging element 522a and the second imaging element 522b can be performed. In this example, the exposure and the reading of the image data of the first imaging element 522a and the second imaging element 522b are performed based on the timing determined by the common synchronization signal.

[0236] In Figure 14In the illustrated example, the pixel data read start timing Rl of the first imaging element 522a coincides with the pixel data read start timing Rl of the second imaging element 522b. However, the pixel data read start timing Rl of the first imaging element 522a can not coincide with the pixel data read start timing Rl of the second imaging element 522b.

[0237] Figure 15 Another example of a timing chart of light source emission and imaging element exposure in the second mode of the first embodiment is shown. In the illustrated example, the pixel data read start timing Rl of the first imaging element 522a and the pixel data read start timing Rl of the second imaging element 522b are offset by 1 / 2 of the exposure time of each image frame, and do not overlap in time. Further, the pixel data read start timing Rl of the first imaging element 522a and the pixel data read start timing Rl of the second imaging element 522b are offset by 1 / 2 of the exposure time of each image frame, and do not overlap in time. Figure 15 The exposure time of each image frame of the first imaging element 522a and the second imaging element 522b of the illustrated example is Figure 15 The exposure time of each image frame of the illustrated example is twice. Figure 14

[0238] As described above, the first imaging element 522a continuously and repeatedly outputs the image signal of the wideband light image frame exposed by the wideband reflected light Lwl (i.e., the image signal based on the wideband reflected light Lwl). Further, the second imaging element 522b continuously and repeatedly outputs the image signal of the second fluorescent light image frame exposed by the second fluorescent light Lw3 (i.e., the image signal based on the second fluorescent light Lw3).

[0239] Then, based on the image signal of the wideband light image frame, a normal light capture image of the observation target S as a reflected image of the wideband light (white light) is generated. Further, based on the image signal of the second fluorescent light image frame, a second fluorescent light capture image of the observation target S as a captured image based on the second fluorescent light Lw3 is generated.

[0240] As described above, in this mode, within a common time frame, a normal light capture image as a reflected image of visible light (white light) and a second fluorescent light capture image in which a second substance of the observation target S is emphasized, i.e., the second substance emits fluorescent light from the observation target S excited by narrowband light, are acquired. Therefore, the user can compare and observe the normal light capture image and the second fluorescent light capture image of the observation target S and observe a combined image (superimposed image) formed by these images via the display device 70.

[0241] ​Note that in the above example, the broadband light and the second narrowband light are continuously emitted from the light source apparatus 10 (i.e., continuous light emission), but the light source apparatus 10 can also be controlled by the control apparatus 90 (control section 94) to turn off the light emission of each of the broadband light and the second narrowband light midway. For example, the light source apparatus 10 can repeatedly turn on and off the emission of the broadband light and the second narrowband light, and can emit the broadband light and the second narrowband light in a time-division manner.

[0242] However, by continuously emitting the broadband light and the second narrowband light by the light source apparatus 10, the first imaging element 522a can continuously receive the broadband reflected light Lwl, and the second imaging element 522b can continuously receive the first fluorescent light. As a result, in the first imaging element 522a and the second imaging element 522b, the amount of charge accumulation increases with long-time exposure, and a bright captured image can be acquired, and an increase in noise due to gain adjustment can be suppressed. Furthermore, all frames of the first imaging element 522a and the second imaging element 522b can be used to generate a captured image. By preventing the occurrence of a large number of frames that do not perform imaging in this way, a significant reduction in frame rate can be avoided and a smooth video can be provided.

[0243] <Third Mode>

[0244] The third mode of the present embodiment is an observation mode in which the broadband light, the first narrowband light, and the second narrowband light are irradiated to the observation target S to acquire a captured image based on the broadband reflected light Lwl, the first fluorescent light Lw2, and the second fluorescent light Lw3 from the observation target S.

[0245] That is, the control apparatus 90 (control section 94) controls the light source apparatus 10 (broadband light source 11, first narrowband light source 12, and second narrowband light source 13) to emit the broadband light and the first narrowband light in a time-division manner from the light source apparatus 10, and to continuously emit the second narrowband light. As a result, the broadband light and the first narrowband light are emitted to the observation target S in a time-division manner, and the second narrowband light is continuously emitted to the observation target S.

[0246] Then, the optical element 15 sequentially guides the first light flux Lfl including the broadband reflected light Lwl from the observation target S irradiated with the broadband light and the first light flux Lfl including the first fluorescent light Lw2 from the observation target S irradiated with the first narrowband light to the first imaging element 522a. Also, the optical element 15 continuously guides the second light flux Lf2 including the second fluorescent light Lw3 from the observation target irradiated with the second narrowband light to the second imaging element 522b.

[0247] As a result, the first imaging element 522a sequentially receives the first light flux Lf1 including the wideband reflected light Lw1 and the first light flux Lf1 including the first fluorescent light Lw2. Then, the first imaging element 522a outputs the image signal based on the wideband reflected light Lw1 and the image signal based on the first fluorescent light Lw2 sequentially and repeatedly under the control of the control device 90 (control section 94).

[0248] On the other hand, the second imaging element 522b continuously receives the second light flux Lf2 including the second fluorescent light Lw3 and continuously and repeatedly outputs the image signal based on the second fluorescent light Lw3 under the control of the control device 90 (control section 94).

[0249] Then, the image generation section 93 (image processing section 931) generates a captured image (high-resolution color image) of the observation target S based on the wideband reflected light Lw1 from the image signal based on the wideband reflected light Lw1 output from the first imaging element 522a. Further, the image generation section 93 (image processing section 931) generates a captured image (high-resolution color image) of the observation target S based on the first fluorescent light Lw2 from the image signal based on the first fluorescent light Lw2 output from the first imaging element 522a. Further, the image generation section 93 (image processing section 931) generates a captured image (high-sensitivity monochrome image) of the observation target S based on the second fluorescent light Lw3 from the image signal based on the second fluorescent light Lw3 output from the second imaging element 522b. The "high-resolution color image" mentioned here is a color image acquired by a high-resolution imaging element, and the "high-sensitivity monochrome image" is a monochrome image acquired by a high-sensitivity imaging element.

[0250] As described above, in this mode, within a common time frame, a normal light captured image as a reflected image of visible light (white light), a first fluorescent light captured image as an image in which a first substance in the observation target S is emphasized (i.e., the first substance in the observation target S emits fluorescent light from being excited by narrowband light), and a second fluorescent light captured image as an image in which a second substance in the observation target S is emphasized (i.e., the second substance in the observation target S emits fluorescent light from being excited by narrowband light) are acquired. Therefore, the user can compare and observe the normal light captured image, the first fluorescent light captured image, and the second fluorescent light captured image of the observation target S or observe a combined image (superimposed image) formed by these images via the display device 70.

[0251] [Second Embodiment]

[0252] In the present embodiment, elements identical or corresponding to those in the first embodiment described above are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0253] Figure 16is a diagram for explaining the type of light incident to the imaging elements (first imaging element 522a and second imaging element 522b) according to the second embodiment.

[0254] The camera head 50 (specifically, the imaging section 52) of the present embodiment includes a two-plate imaging module (see Figure 3 and Figure 4 ), and includes the first imaging element 522a having a color filter CF and the second imaging element 522b not having a color filter CF.

[0255] The color filter CF provided in the first imaging element 522a of the present embodiment transmits the wideband reflected light Lwl and the first fluorescent light Lw2 (as described later) received by the first imaging element 522a, but can or can not transmit light in a wavelength band different from the wideband reflected light Lwl and the first fluorescent light Lw2 (for example, the second fluorescent light Lw3 and the third fluorescent light Lw4). Note that the second imaging element 522b does not include the color filter CF in the present example, but can include a color filter CF that can transmit the second fluorescent light Lw3 and the third fluorescent light Lw4 as described later.

[0256] For example, the resolution of the first imaging element 522a can be higher than the resolution of the second imaging element 522b, and the sensitivity of the second imaging element 522b can be higher than the sensitivity of the first imaging element 522a. However, the resolution and the sensitivity of the first imaging element 522a and the second imaging element 522b are not limited thereto, and the relative relationship between the resolution and the sensitivity between the first imaging element 522a and the second imaging element 522b is not limited thereto.

[0257] The light source device 10 (see Figure 1B ) emits light from at least one of the wideband light source 11, the first narrowband light source 12, the second narrowband light source 13, and the third narrowband light source 14, and is capable of irradiating the observation target S with at least one of the wideband light, the first narrowband light, the second narrowband light, and the third narrowband light.

[0258] Therefore, the observation light Lf from the observation target S can include the wideband reflected light Lwl which is reflected light as wideband light, the first fluorescent light Lw2 emitted from the first substance excited by the first narrowband light, the second fluorescent light Lw3 emitted from the second substance excited by the second narrowband light, and the third fluorescent light Lw4 emitted from the third substance excited by the third narrowband light. Note that the wideband reflected light Lwl and the first fluorescent light Lw2 are light included in the first wavelength band, and the second fluorescent light Lw3 and the third fluorescent light Lw4 are light included in the second wavelength band outside the first wavelength band.

[0259] The observation light Lf incident on the optical element 15 is split by the optical element 15 into a first light flux Lf1 and a second light flux Lf2. The optical element 15 of the present embodiment guides light included in the first wavelength band to the first imaging element 522a as the first light flux Lf1, and guides light included in the second wavelength band to the second imaging element 522b as the second light flux Lf2.

[0260] As described above, in the present embodiment, the first light flux Lf1 in which light in the wavelength band of the second fluorescent light Lw3 and the third fluorescent light Lw4 in the observation light Lf is partially, substantially, or completely suppressed is guided to the first imaging element 522a. That is, light including at least the broadband reflected light Lwl and the first fluorescent light Lw2 is guided to the first imaging element 522a as the first light flux Lf1. Further, in the observation light Lf, the second light flux Lf2 in which light in the first wavelength band is partially, substantially, or completely suppressed by the optical element 15 is guided to the second imaging element 522b. That is, light including at least the second fluorescent light Lw3 and the third fluorescent light Lw4 included in the second wavelength band is guided to the second imaging element 522b as the second light flux Lf2.

[0261] The medical observation system 100 of the present embodiment having the above-described structure can acquire various captured images of the observation target S according to the following observation modes (first to fifth modes).

[0262] <First to third modes>

[0263] The first to third modes of the present embodiment are similarly performed to the first to third modes of the above-described first embodiment.

[0264] Thus, in the first mode, the broadband light and the first narrowband light are emitted by the light source apparatus 10 in a time-division manner, and the broadband reflected light Lwl and the first fluorescent light Lw2 are received by the first imaging element 522a. Further, in the second mode, the broadband light and the second narrowband light are continuously emitted by the light source apparatus 10, the broadband reflected light Lwl is received by the first imaging element 522a, and the second fluorescent light Lw3 is received by the second imaging element 522b. Further, in the third mode, the broadband light and the first narrowband light are emitted by the light source apparatus 10 in a time-division manner and the second narrowband light is continuously emitted, the broadband reflected light Lwl and the first fluorescent light Lw2 are received by the first imaging element 522a, and the second fluorescent light Lw3 is received by the second imaging element 522b.

[0265] <Fourth mode>

[0266] The fourth mode of the present embodiment is an observation mode in which the broadband light and the third narrowband light are irradiated to the observation target S to acquire a captured image based on the broadband reflected light Lwl and the third fluorescent light Lw4 from the observation target S.

[0267] That is, the control device 90 (the control section 94) controls the light source device 10 (the wideband light source 11 and the third narrowband light source 14), and the wideband light and the third narrowband light are continuously emitted from the light source device 10. It should be noted that, in this mode, the first narrowband light source 12 and the second narrowband light source 13 are placed in an off state, and the first narrowband light and the second narrowband light are not emitted from the light source device 10.

[0268] Then, the optical element 15 continuously guides the first light flux Lf1 including the wideband reflected light Lw1 from the observation target S irradiated with the wideband light to the first imaging element 522a. In addition, the optical element 15 continuously guides the second light flux Lf2 including the third fluorescent light Lw4 from the observation target S irradiated with the third narrowband light to the second imaging element 522b.

[0269] As a result, the first imaging element 522a continuously receives the first light flux Lf1 including the wideband reflected light Lw1 under the control of the control device 90 (the control section 94), and continuously and repeatedly outputs an image signal based on the wideband reflected light Lw1. In addition, the second imaging element 522b continuously receives the second light flux Lf2 including the third fluorescent light Lw4 under the control of the control device 90 (the control section 94), and continuously and repeatedly outputs an image signal based on the third fluorescent light Lw4.

[0270] Then, the image generation section 93 (the image processing section 931) generates a captured image (a high-resolution color image) of the observation target S based on the wideband reflected light Lw1 from the image signal based on the wideband reflected light Lw1 output from the first imaging element 522a. In addition, the image generation section 93 (the image processing section 931) generates a captured image (a high-sensitivity monochrome image) of the observation target S based on the third fluorescent light Lw4 from the image signal based on the third fluorescent light Lw4 output from the second imaging element 522b. The “high-resolution color image” mentioned here is a color image acquired by a high-resolution imaging element, and the “high-sensitivity monochrome image” is a monochrome image acquired by a high-sensitivity imaging element.

[0271] As described above, in this mode, within a common time frame, a normal light captured image that is a reflected image of visible light (white light) and a third fluorescent light captured image in which a third substance in the observation target S is emphasized, that is, a third substance in the observation target S excited by narrowband light emits fluorescent light are acquired. Therefore, the user can compare and observe the normal light captured image and the third fluorescent light captured image of the observation target S and observe a combined image (an overlay image) formed by these images via the display device 70.

[0272] <Mode 5>

[0273] The fifth mode of the present embodiment is an observation mode in which the broadband light and the first to third narrow-band lights are irradiated to the observation target S to acquire images based on the broadband reflected light Lwl and the first to third fluorescent lights Lw2 to Lw4 from the observation target S.

[0274] That is, the control device 90 (the control section 94) controls the light source device 10 (the broadband light source 11 and the first to third narrow-band light sources 12 to 14), and the broadband light and the first narrow-band light are emitted from the light source device 10 in a time-division manner, and the second narrow-band light and the third narrow-band light are emitted in a time-division manner. As a result, the broadband light and the first narrow-band light are emitted to the observation target S in a time-division manner, and the second narrow-band light and the third narrow-band light are emitted to the observation target S in a time-division manner. Note that each of the broadband light and the first narrow-band light can also be reflected simultaneously with one of the second narrow-band light and the third narrow-band light, and emitted to the observation target S simultaneously.

[0275] Then, the optical element 15 sequentially guides the first light flux Lfl including the broadband reflected light Lwl from the observation target S irradiated with the broadband light and the first light flux Lfl including the first fluorescent light Lw2 from the observation target S irradiated with the first narrow-band light to the first imaging element 522a. Further, the optical element 15 sequentially guides the second light flux Lf2 including the second fluorescent light Lw3 from the observation target S irradiated with the second narrow-band light and the second light flux Lf2 including the third fluorescent light Lw4 from the observation target S irradiated with the third narrow-band light to the second imaging element 522b.

[0276] As a result, the first imaging element 522a sequentially receives the first light flux Lfl including the broadband reflected light Lwl and the first light flux Lfl including the first fluorescent light Lw2. Then, the first imaging element 522a outputs an image signal based on the broadband reflected light Lwl and an image signal based on the first fluorescent light Lw2 sequentially and repeatedly under the control of the control device 90 (the control section 94).

[0277] On the other hand, the second imaging element 522b sequentially receives the second light flux Lf2 including the second fluorescent light Lw3 and the second light flux Lf2 including the third fluorescent light Lw4. Then, the second imaging element 522b outputs an image signal based on the second fluorescent light Lw3 and an image signal based on the third fluorescent light Lw4 sequentially and repeatedly under the control of the control device 90 (the control section 94).

[0278] Then, the image generation section 93 (the image processing section 931) generates a captured image (a high-resolution color image) of the observation target S based on the wide-band reflected light Lwl from the image signal based on the wide-band reflected light Lwl output from the first imaging element 522a. Further, the image generation section 93 (the image processing section 931) generates a captured image (a high-resolution color image) of the observation target S based on the first fluorescent light Lw2 from the image signal based on the first fluorescent light Lw2 output from the first imaging element 522a. The "high-resolution color image" mentioned here is a color image acquired by a high-resolution imaging element.

[0279] Further, the image generation section 93 (the image processing section 931) generates a captured image (a high-sensitivity monochrome image) of the observation target S based on the second fluorescent light Lw3 from the image signal based on the second fluorescent light Lw3 output from the second imaging element 522b. Further, the image generation section 93 (the image processing section 931) generates a captured image (a high-sensitivity monochrome image) of the observation target S based on the third fluorescent light Lw4 from the image signal based on the third fluorescent light Lw4 output from the second imaging element 522b. The "high-sensitivity monochrome image" mentioned here is a monochrome image acquired by a high-sensitivity imaging element.

[0280] As described above, in this mode, within a common time frame, a normal light captured image that is a reflected image of visible light (white light) and first to third fluorescent light captured images in which first to third substances within the observation target S are emphasized, that is, fluorescent light emitted from the first to third substances in the observation target S excited by narrow-band light are acquired. Therefore, the user can compare and observe the normal light captured image, the first fluorescent light captured image, the second fluorescent light captured image, and the third fluorescent light captured image of the observation target S or observe a combined image (a superimposed image) formed by these images via the display device 70.

[0281] As described above, according to the present embodiment, the wide-band reflected light Lwl and the first fluorescent light Lw2 of the observation light Lf are imaged by the first imaging element 522a, and the second fluorescent light Lw3 and the third fluorescent light Lw4 are imaged by the second imaging element 522b.

[0282] Therefore, a high-resolution color image is obtained as a captured image from the wide-band reflected light Lwl and the first fluorescent light Lw2 in the visible light wavelength band having color information.

[0283] On the other hand, a high-sensitivity monochrome image is obtained as a captured image from the second fluorescent light Lw3 and the third fluorescent light Lw4 in the invisible light wavelength band that does not have color information. Therefore, even in a case where the first imaging element 522a is difficult to perform appropriate imaging due to a small amount of light of the second fluorescent light Lw3 and the third fluorescent light Lw4, such imaging of the second fluorescent light Lw3 and the third fluorescent light Lw4 is appropriately performed by the second imaging element 522b having excellent sensitivity.

[0284] [Third Embodiment]

[0285] In the present embodiment, the same reference signs are attached to the same or corresponding components as those of the first and second embodiments described above, and detailed description is omitted.

[0286] Figure 17 is a diagram for explaining the types of light incident to the imaging elements (the first imaging element 522a and the second imaging element 522b) according to the third embodiment.

[0287] The camera head 50 (specifically, the imaging section 52) of the present embodiment includes a two-plate imaging module (see Figure 3 and Figure 4 ), and includes the first imaging element 522a having a color filter CF and the second imaging element 522b not having a color filter CF. For example, the resolution of the first imaging element 522a can be higher than that of the second imaging element 522b, and the sensitivity of the second imaging element 522b can be higher than that of the first imaging element 522a. However, the resolution and the sensitivity of the first imaging element 522a and the second imaging element 522b are not limited thereto, and the relative relationship between the resolution and the sensitivity between the first imaging element 522a and the second imaging element 522b is not limited thereto.

[0288] The color filter CF provided in the first imaging element 522a of the present embodiment transmits the wideband reflected light Lw1 and the first fluorescent light Lw2 (as described later) received by the first imaging element 522a, but can or can not transmit light (for example, the second fluorescent light Lw3) in a wavelength band different from the wideband reflected light Lw1 and the first fluorescent light Lw2. Note that the second imaging element 522b does not include the color filter CF in the present example, but can include a color filter CF capable of transmitting the wideband reflected light Lw1, the first fluorescent light Lw2, and the second fluorescent light Lw3, as described later.

[0289] The light source device 10 (see Figure 1A ) emits light from at least one of the wideband light source 11, the first narrowband light source 12, and the second narrowband light source 13, and can irradiate the observation target S with at least one of the wideband light, the first narrowband light, and the second narrowband light.

[0290] Therefore, the observation light Lf from the observation target S can include a wideband reflection light Lwl that is reflection light of the wideband light, a first fluorescent light Lw2 emitted from a first substance excited by the first narrowband light, and a second fluorescent light Lw3 emitted from a second substance excited by the second narrowband light. Note that the wideband reflection light Lwl and the first fluorescent light Lw2 are lights included in the first wavelength band, and the second fluorescent light Lw3 is a light included in a second wavelength band outside the first wavelength band.

[0291] The observation light Lf incident on the optical element 15 is split by the optical element 15 into a first light flux Lfl and a second light flux Lf2. The optical element 15 of the present embodiment guides a portion of the light included in the first wavelength band as the first light flux Lfl to the first imaging element 522a, and guides a portion of the light included in the first wavelength band and the light included in the second wavelength band as the second light flux Lf2 to the second imaging element 522b.

[0292] As described above, in the present embodiment, the first light flux Lfl in which the light in the first wavelength band is partially suppressed and the light in the wavelength band of the second fluorescent light Lw3 is partially, substantially, or completely suppressed in the observation light Lf is guided to the first imaging element 522a. That is, the light including at least a portion of the wideband reflection light Lwl is guided to the first imaging element 522a as the first light flux Lfl. Further, the second light flux Lf2 in which the light of the first wavelength band is partially suppressed in the observation light Lf is guided to the second imaging element 522b. That is, the light including the wideband reflection light Lwl and at least a portion of the first fluorescent light Lw2 and the second fluorescent light Lw3 is guided to the second imaging element 522b as the second light flux Lf2.

[0293] The medical observation system 100 of the present embodiment having the above-described structure can acquire various captured images of the observation target S according to the following observation modes (first mode to third mode).

[0294] <First Mode>

[0295] The first mode of the present embodiment is an observation mode in which the wideband light and the first narrowband light are irradiated to the observation target S to acquire a captured image based on the wideband reflection light Lwl and the first fluorescent light Lw2 from the observation target S.

[0296] The control device 90 (control section 94 (see Figure 7 )) controls the light source device 10 (wideband light source 11 and first narrowband light source 12 (see Figure 1A )) to emit the wideband light and the first narrowband light from the light source device 10 in a time-division manner, and to irradiate the observation target S with the wideband light and the first narrowband light in a time-division manner. Note that in this mode, the second narrowband light source 13 is placed in an off state, and the second narrowband light is not emitted from the light source device 10.

[0297] Then, the optical element 15 sequentially guides the first light flux Lfl including the broadband reflected light Lwl from the observation target S irradiated with the broadband light and the first light flux Lfl including the first fluorescent light Lw2 from the observation target S irradiated with the first narrowband light to the first imaging element 522a. Further, the optical element 15 sequentially guides the second light flux Lf2 including the broadband reflected light Lwl from the observation target S irradiated with the broadband light and the second light flux Lf2 including the first fluorescent light Lw2 from the observation target S irradiated with the first narrowband light to the second imaging element 522b.

[0298] As a result, the first imaging element 522a sequentially receives the first light flux Lfl including the broadband reflected light Lwl and the first light flux Lfl including the first fluorescent light Lw2. Further, the second imaging element 522b sequentially receives the second light flux Lf2 including the broadband reflected light Lwl and the second light flux Lf2 including the first fluorescent light Lw2.

[0299] Then, the first imaging element 522a and the second imaging element 522b each sequentially and repeatedly output an image signal based on the broadband reflected light Lwl and an image signal based on the first fluorescent light Lw2 under the control of the control device 90 (control section 94 (see Figure 7 ).

[0300] Then, under the control of the control section 94, the image generation section 93 (specifically, the image processing section 931 (see Figure 7 ) generates a captured image (high-resolution color image) of the observation target S based on the broadband reflected light Lwl based on the image signal output from the first imaging element 522a that has received the first light flux Lfl including the broadband reflected light Lwl. Further, under the control of the control section 94, the image generation section 93 (image processing section 931) generates a captured image (high-sensitivity monochrome image) of the observation target S based on the first fluorescent light Lw2 based on the image signal output from the second imaging element 522b that has received the second light flux Lf2 including the first fluorescent light Lw2. The "high-resolution color image" mentioned here is a color image acquired by a high-resolution imaging element, and the "high-sensitivity monochrome image" is a monochrome image acquired by a high-sensitivity imaging element.

[0301] Figure 18 An example of a timing chart of light source emission and imaging element exposure in the first mode of the third embodiment is shown.

[0302] Figure 18 (a) indicates the exposure state of the first imaging element 522a, and (c) indicates the exposure state of the second imaging element 522b. In Figure 18In (a) and (c) of FIG. 21, the vertical axis represents the horizontal line of the first imaging element 522a and the second imaging element 522b, the horizontal axis represents time, and the line R1 represents the pixel data read start timing for each horizontal line with respect to each image frame. The "wideband light image frame" between the lines R1 is an image frame for receiving (exposure) of the wideband reflected light Lwl from the observation target S, and the "first fluorescent light image frame" between the lines R1 is an image frame for receiving (exposure) of the first fluorescent light Lw2 from the observation target S. Figure 18 (b) of FIG. 21 shows the emission timing of the wideband light in the wideband light source 11, and Figure 18 (d) of FIG. 21 shows the emission timing of the first narrowband light in the first narrowband light source 12.

[0303] In this mode, as described above, the light emission in the light source apparatus 10 and the irradiation of the wideband light and the first narrowband light to the observation target S are performed in a time-division manner. Then, both the wideband reflected light Lwl and the first fluorescent light Lw2 from the observation target S are guided to both the first imaging element 522a and the second imaging element 522b, and sequentially received by each of the first imaging element 522a and the second imaging element 522b. Then, in the above-described example, the captured image based on the wideband reflected light Lwl is generated based on the image signal from the first imaging element 522a, and the captured image based on the first fluorescent light Lw2 is generated based on the image signal from the second imaging element 522b.

[0304] Accordingly, the control apparatus 90 (control section 94) controls so that the timing of the time-division light emission of the light source apparatus 10 corresponds to the timing of reading the image data from the first imaging element 522a and the second imaging element 522b. Specifically, based on the common synchronization signal, the time-division light emission of the wideband light and the first narrowband light in the wideband light source 11 and the first narrowband light source 12 is performed, and the exposure and the image data reading in the first imaging element 522a and the second imaging element 522b are performed. More specifically, the wideband light and the first narrowband light are alternately emitted in time, respectively, so that the first imaging element 522a and the second imaging element 522b are not simultaneously exposed to both the wideband reflected light Lwl and the first fluorescent light Lw2.

[0305] Then, the image data is read so that the image signal of the wideband light image frame exposed by the wideband reflected light Lwl and the image signal of the first fluorescent light image frame exposed by the first fluorescent light Lw2 are output from the first imaging element 522a and the second imaging element 522b. As a result, the first imaging element 522a and the second imaging element 522b alternately repeat the output of the image signal of the wideband light image frame and the image signal of the first fluorescent light image frame, respectively.

[0306] Then, the image generation section 93 (the image processing section 931) generates a normal light capture image of the observation target S, which is a reflection image of the wideband light (white light), from the image signal of the wideband light image frame output from the first imaging element 522a. Further, the image generation section 93 (the image processing section 931) generates a first fluorescent light capture image, which is a capture image based on the first fluorescent light Lw2 of the observation target S, from the image signal of the first fluorescent light image frame output from the second imaging element 522b.

[0307] As described above, in this mode, within a common time frame, the normal light capture image that is a reflection image of the visible light (white light) and the first fluorescent light capture image in which the first substance of the observation target S is emphasized, that is, the fluorescent light emitted from the first substance of the observation target S excited by the narrowband light are acquired. Therefore, the user can compare and observe the normal light capture image and the first fluorescent light capture image of the observation target S and observe a combined image (superimposed image) formed by these images via the display device 70 (see FIG. 6). Figure 1A ).

[0308] Note that, in the example shown in Figure 18 , the emission of the wideband light and the first narrowband light is started and terminated when the image data is not read from the first imaging element 522a and the second imaging element 522b. Therefore, in the wideband light image frame of the first imaging element 522a and the second imaging element 522b, the first fluorescent light Lw2 from the observation target S irradiated with the first narrowband light can be suppressed from being incident to the first imaging element 522a. Further, in the first fluorescent light image frame of the first imaging element 522a and the second imaging element 522b, the wideband reflection light Lwl from the observation target S irradiated with the wideband light can be suppressed from being incident to the first imaging element 522a and the second imaging element 522b.

[0309] Note that the start timing and the end timing of the light emission of the wideband light and the first narrowband light are not limited to the example shown in Figure 18 , and can be set to an arbitrary timing. For example, the emission of the wideband light and the first narrowband light can be started and terminated when the image data is read from the first imaging element 522a and the second imaging element 522b (see Figure 18"R1") can start or end the emission of one or both of the broadband light and the first narrow-band light. For example, in a case where the intensity of the fluorescent light that is the light-receiving target in the first fluorescent light image frame is weak (i.e., in a case where the amount of fluorescent light emission is small), the first narrow-band light can be emitted from the first narrow-band light source 12 while the image data of the broadband light image frame is read. In this case, the exposure time of the fluorescent light of the first fluorescent light image frame can be extended, which is advantageous for obtaining the image data of the bright first fluorescent light image frame. Specifically, in a case where the first fluorescent light Lw2 has an amount of light sufficiently smaller than the broadband reflected light Lw1 and the influence of the first fluorescent light Lw2 on the broadband light image frame is sufficiently smaller than the influence of the broadband reflected light Lw1 on the broadband light image frame, the first narrow-band light source 12 can continuously emit the first narrow-band light.

[0310] Note that, in this mode, the image signal of the first fluorescent light image frame is also output from the first imaging element 522a, and the image signal of the broadband light image frame is also output from the second imaging element 522b. However, in the above example, these image frames are not used for generating the captured image.

[0311] In the above example, the image data of these image frames that are not used for generating the captured image are also repeatedly output as image signals from the imaging elements (the first imaging element 522a and the second imaging element 522b), but the image data of the image frames that are not used for generating the captured image can not be output as image signals from the imaging elements. That is, when the image data of the image frames used for generating the captured image are output as image signals from the imaging elements, the accumulated charges of the imaging elements are reset with respect to the image frames that are not used for generating the captured image, and can also not be output as image signals from the imaging elements.

[0312] Further, in the above example, these image frames that are not used for generating the captured image (i.e., the first fluorescent light image frame from the first imaging element 522a and the broadband light image frame from the second imaging element 522b) can also be used for generating the captured image. In this case, the captured image generated from the first fluorescent light image frame from the first imaging element 522a and the broadband light image frame from the second imaging element 522b can or can not be used for generating the output image.

[0313] The captured image that is not used for generating the output image can be used for any purpose. For example, the image generation section 93 (see Figure 7 ) can perform a correction process with respect to the brightness of the output image based on the image analysis result of the captured image that is not used for generating the output image. Further, a process related to the adjustment of the focus position, such as contrast auto focus (AF), can be performed based on the image analysis result of the captured image that is not used for generating the output image, and the focus position can be adjusted based on the contrast or the spatial frequency of such a captured image.

[0314] That is, a captured image based on the first fluorescent light Lw2 can be generated based on the image signal of the first fluorescent light image frame from the first imaging element 522a. For example, a captured image based on the first fluorescent light Lw2 can be generated based on the image signal of the first fluorescent light image frame from both the first imaging element 522a and the second imaging element 522b.

[0315] In addition, a captured image based on the wideband reflected light Lwl can be generated based on the image signal of the wideband light image frame from the second imaging element 522b. That is, a captured image based on the wideband reflected light Lwl can be generated based on the image signal of the wideband light image frame from both the first imaging element 522a and the second imaging element 522b.

[0316] <Second Mode>

[0317] The second mode of the present embodiment is an observation mode in which the wideband light and the second narrowband light are irradiated to the observation target S to acquire a captured image based on the wideband reflected light Lwl and the second fluorescent light Lw3 from the observation target S.

[0318] That is, the control device 90 (the control section 94) controls the light source device 10 (the wideband light source 11 and the second narrowband light source 13), and the wideband light and the second narrowband light are time-divisionally emitted from the light source device 10, and the wideband light and the second narrowband light are time-divisionally emitted to the observation target S. Note that, in this mode, the first narrowband light source 12 is placed in an off state, and the first narrowband light is not emitted from the light source device 10.

[0319] Then, the optical element 15 guides the first light flux Lf1 including the wideband reflected light Lwl from the observation target S irradiated with the wideband light to the first imaging element 522a. In addition, the optical element 15 guides the second light flux Lf2 including the wideband reflected light Lwl from the observation target S irradiated with the wideband light and the second light flux Lf2 including the second fluorescent light Lw3 from the observation target S irradiated with the second narrowband light to the second imaging element 522b in order.

[0320] As a result, the first imaging element 522a receives the first light flux Lf1 including the wideband reflected light Lwl. In addition, the second imaging element 522b receives the second light flux Lf2 including the wideband reflected light Lwl and the second light flux Lf2 including the second fluorescent light Lw3 in order.

[0321] Then, the first imaging element 522a repeatedly outputs the image signal based on the wideband reflected light Lwl under the control of the control device 90 (the control section 94). In addition, the second imaging element 522b sequentially and repeatedly outputs the image signal based on the wideband reflected light Lwl and the image signal based on the second fluorescent light Lw3 under the control of the control device 90 (the control section 94).

[0322] Then, under the control of the control section 94, the image generation section 93 (image processing section 931) generates a captured image (high-resolution color image) of the observation target S based on the broadband reflected light Lwl based on the image signal output from the first imaging element 522a that has received the first light flux Lf1 including the broadband reflected light Lwl. Further, under the control of the control section 94, the image generation section 93 (image processing section 931) generates a captured image (high-sensitivity monochrome image) of the observation target S based on the second fluorescent light Lw3 based on the image signal output from the second imaging element 522b that has received the second light flux Lf2 including the second fluorescent light Lw3. The "high-resolution color image" mentioned here is a color image acquired by a high-resolution imaging element, and the "high-sensitivity monochrome image" is a monochrome image acquired by a high-sensitivity imaging element.

[0323] As described above, in this mode, within a common time frame, a normal light captured image that is a reflected image of visible light (white light) and a second fluorescent light captured image in which the second substance of the observation target S is emphasized, that is, the second fluorescent light emitted from the second substance of the observation target S excited by the narrowband light are acquired. Therefore, the user can compare and observe the normal light captured image and the second fluorescent light captured image of the observation target S and observe a combined image (superimposed image) formed by these images via the display device 70.

[0324] Note that, in the above example, the broadband light and the second narrowband light are emitted in a time-division manner, but the light source device 10 can also continuously emit the second narrowband light while repeating the on and off of the emission of the broadband light under the control of the control device 90 (control section 94).

[0325] In this case, the light source device 10 (broadband light source 11) emits the broadband light in the broadband light image frame of the first imaging element 522a so that the broadband reflected light Lwl is exposed to the first imaging element 522a. On the other hand, the light source device 10 (broadband light source 11) stops the emission of the broadband light in the second fluorescent light image frame of the second imaging element 522b so that the broadband reflected light Lwl is not exposed to the second imaging element 522b. Thereby, it is possible to appropriately output the image signal of the broadband light image frame from the first imaging element 522a, and it is possible to appropriately output the image signal of the second fluorescent light image frame from the second imaging element 522b.

[0326] Note that, the start time and the end time of the light emission of the broadband light and the second narrowband light are not limited and can be set to an arbitrary time. For example, when reading the image data from the first imaging element 522a and the second imaging element 522b (see Figure 18The light emission of one or both of the broadband light and the second narrowband light can be started or ended in response to the image signal output from the second imaging element 522b (see "R1" in FIG. 6). For example, the broadband light can be emitted from the broadband light source 11 at the time of reading the image data of the second fluorescent light image frame.

[0327] Note that, in this mode, the image signal of the broadband light image frame is also output from the second imaging element 522b, but in the above example, the broadband light image frame from the second imaging element 522b is not used for generating the captured image. In the above example, the image data of the broadband light image frame which is not used for generating the captured image is repeatedly output as the image signal from the second imaging element 522b, but the image data of the broadband light image frame which is not used for generating the captured image can not be output as the image signal from the second imaging element 522b.

[0328] Further, in the above example, the captured image based on the broadband reflected light Lwl can be generated based on the image signal of the broadband light image frame which is not used for generating the captured image from the second imaging element 522b. That is, the captured image based on the broadband reflected light Lwl can be generated based on the image signal of the broadband light image frame from both the first imaging element 522a and the second imaging element 522b.

[0329] The captured image generated in this way can or can not be used for generating the output image.

[0330] The captured image which is not used for generating the output image can be used for any purpose (for example, correction processing regarding the brightness of the output image or adjustment processing regarding the focus position).

[0331] <Third Mode>

[0332] The third mode of the present embodiment is an observation mode in which the broadband light, the first narrowband light, and the second narrowband light are irradiated to the observation target S to acquire a captured image based on the broadband reflected light Lwl, the first fluorescent light Lw2, and the second fluorescent light Lw3 from the observation target S.

[0333] That is, the control device 90 (control section 94) controls the light source device 10 (broadband light source 11, first narrowband light source 12, and second narrowband light source 13), and the broadband light, the first narrowband light, and the second narrowband light are emitted from the light source device 10 in a time-division manner. As a result, the broadband light, the first narrowband light, and the second narrowband light are emitted to the observation target S in a time-division manner.

[0334] Then, the optical element 15 sequentially guides the first light flux Lfl including the wideband reflected light Lwl from the observation target S irradiated with the wideband light and the first light flux Lfl including the first fluorescent light Lw2 from the observation target S irradiated with the first narrowband light to the first imaging element 522a. Further, the optical element 15 sequentially guides the second light flux Lf2 including the wideband reflected light Lwl from the observation target S irradiated with the wideband light, the second light flux Lf2 including the first fluorescent light Lw2 from the observation target S irradiated with the first narrowband light, and the second light flux Lf2 including the second fluorescent light Lw3 from the observation target S irradiated with the second narrowband light to the second imaging element 522b.

[0335] As a result, the first imaging element 522a sequentially receives the first light flux Lfl including the wideband reflected light Lwl and the first light flux Lfl including the first fluorescent light Lw2. Then, the first imaging element 522a sequentially and repeatedly outputs an image signal based on the wideband reflected light Lwl and an image signal based on the first fluorescent light Lw2 under the control of the control device 90 (control section 94).

[0336] On the other hand, the second imaging element 522b sequentially receives the second light flux Lf2 including the wideband reflected light Lwl, the second light flux Lf2 including the first fluorescent light Lw2, and the second light flux Lf2 including the second fluorescent light Lw3. Then, the second imaging element 522b sequentially and repeatedly outputs an image signal based on the wideband reflected light Lwl, an image signal based on the first fluorescent light Lw2, and an image signal based on the second fluorescent light Lw3 under the control of the control device 90 (control section 94).

[0337] Then, under the control of the control section 94, the image generation section 93 (image processing section 931) generates a captured image (high-resolution color image) of the observation target S based on the wideband reflected light Lwl based on the image signal output from the first imaging element 522a that has received the first light flux Lfl including the wideband reflected light Lwl. Further, under the control of the control section 94, the image generation section 93 (image processing section 931) generates a captured image (high-sensitivity monochrome image) of the observation target S based on the first fluorescent light Lw2 based on the image signal output from the second imaging element 522b that has received the second light flux Lf2 including the first fluorescent light Lw2. Further, under the control of the control section 94, the image generation section 93 (image processing section 931) generates a captured image (high-sensitivity monochrome image) of the observation target S based on the second fluorescent light Lw3 based on the image signal output from the second imaging element 522b that has received the second light flux Lf2 including the second fluorescent light Lw3. The "high-resolution color image" mentioned here is a color image acquired by a high-resolution imaging element, and the "high-sensitivity monochrome image" is a monochrome image acquired by a high-sensitivity imaging element.

[0338] As described above, in this mode, the normal light capture image as a reflection image of visible light (white light), and the first and second fluorescent capture images as images in which the first and second substances in the observation target S are emphasized, that is, the first and second substances in the observation target S emit fluorescence from the narrow-band light excitation are acquired in a common time frame. Therefore, the user can compare and observe the normal light capture image, the first and second fluorescent capture images of the observation target S, and can observe a combined image (superimposed image) formed from these images.

[0339] Note that, in this mode, the image signal of the first fluorescent image frame is also output from the first imaging element 522a, and the image signal of the wide-band light image frame is also output from the second imaging element 522b. However, in the above example, these image frames are not used for generating the capture images. In the above example, the image data of these image frames not used for generating the capture images is also repeatedly output as an image signal from the imaging elements (the first imaging element 522a and the second imaging element 522b), but the image data of the image frames not used for generating the capture images can not be output as an image signal from the imaging elements.

[0340] Further, in the above example, the capture image based on the first fluorescent light Lw2 can be generated based on the image signal of the first fluorescent image frame not used for generating the capture images from the first imaging element 522a. For example, the capture image based on the first fluorescent light Lw2 can be generated based on the image signal of the first fluorescent image frame from both the first imaging element 522a and the second imaging element 522b. Further, the capture image based on the wide-band reflection light Lw1 can be generated based on the image signal of the wide-band light image frame from the second imaging element 522b. That is, the capture image based on the wide-band reflection light Lw1 can be generated based on the image signal of the wide-band light image frame from both the first imaging element 522a and the second imaging element 522b.

[0341] The capture images generated in this way can or can not be used for generating the output image.

[0342] The capture images not used for generating the output image can be used for any purpose (for example, correction processing regarding the brightness of the output image or adjustment processing regarding the focus position).

[0343] [Fourth Embodiment]

[0344] In the present embodiment, elements same as or corresponding to the elements in the above first to third embodiments are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0345] Figure 19This is a diagram illustrating the type of light incident on the imaging elements (first imaging element 522a and second imaging element 522b) according to the fourth embodiment.

[0346] The camera head 50 (specifically, the imaging unit 52) ​​in this embodiment includes a two-plate imaging module (see...). Figure 3 and Figure 4 The imaging element 522a includes a first imaging element 522a having a color filter CF and a second imaging element 522b not having a color filter CF. The first imaging element 522a has relatively lower sensitivity and higher resolution (e.g., 4K resolution) than the second imaging element 522b, while the second imaging element 522b has relatively higher sensitivity and lower resolution (e.g., HD resolution) than the first imaging element 522a.

[0347] The color filter CF provided in the first imaging element 522a of this embodiment transmits broadband reflected light Lw1 (as described later) received by the first imaging element 522a, but may or may not transmit light of a different wavelength band than the broadband reflected light Lw1 (e.g., the second fluorescence Lw3). It should be noted that the second imaging element 522b does not include the color filter CF of this example, but may include a color filter CF capable of transmitting the first fluorescence Lw2 and the second fluorescence Lw3 as described later.

[0348] Light source device 10 (see Figure 1A The target S is illuminated by at least one of the broadband light source 11, the first narrowband light source 12, and the second narrowband light source 13.

[0349] Therefore, the observation light Lf from the observed target S may include broadband reflected light Lw1 as broadband light, first fluorescence Lw2 emitted from a first substance excited by a first narrowband light, and second fluorescence Lw3 emitted from a second substance excited by a second narrowband light. It should be noted that the broadband reflected light Lw1 and the first fluorescence Lw2 are light included within a first wavelength band, while the second fluorescence Lw3 is light included within a second wavelength band outside the first wavelength band.

[0350] The observation light Lf incident on the optical element 15 is separated by the optical element 15 into a first luminous flux Lf1 and a second luminous flux Lf2. In this embodiment, the optical element 15 guides a portion of the light included in the first wavelength band as the first luminous flux Lf1 to the first imaging element 522a, and guides at least the first fluorescence Lw2 and light including the light in the second wavelength band as the second luminous flux Lf2 to the second imaging element 522b.

[0351] As described above, in the present embodiment, the first light flux Lf1 in which the light in the wavelength band of the first fluorescent light Lw2 and the second fluorescent light Lw3 in the observation light Lf is partially, substantially, or completely suppressed is guided to the first imaging element 522a. That is, the light including at least a part of the broadband reflected light Lw1 is guided to the first imaging element 522a as the first light flux Lf1. Further, the second light flux Lf2 in which the light in the wavelength band other than the first wavelength band of the first fluorescent light Lw2 in the observation light Lf is partially, substantially, or completely suppressed is guided to the second imaging element 522b. That is, the light including at least the first fluorescent light Lw2 and the second fluorescent light Lw3 is guided to the second imaging element 522b as the second light flux Lf2.

[0352] The medical observation system 100 of the present embodiment having the above-described structure can acquire various captured images of the observation target S according to the following observation modes (first mode to third mode).

[0353] <First Mode>

[0354] The first mode of the present embodiment is an observation mode in which the broadband light and the first narrowband light are irradiated to the observation target S to acquire a captured image based on the broadband reflected light Lwl and the first fluorescent light Lw2 from the observation target S.

[0355] That is, the control device 90 (control section 94 (see Figure 7 )) controls the light source device 10 (broadband light source 11 and first narrowband light source 12 (see Figure 1A )) to emit the broadband light and the first narrowband light from the light source device 10 in a time-division manner, and to emit the broadband light and the first narrowband light to the observation target S in a time-division manner. Note that, in this mode, the second narrowband light source 13 is placed in an off state, and the second narrowband light is not emitted from the light source device 10.

[0356] Then, the optical element 15 guides the first light flux Lf1 including the broadband reflected light Lwl from the observation target S irradiated with the broadband light (while the light in the wavelength band of the first fluorescent light Lw2 is partially, substantially, or completely suppressed) to the first imaging element 522a. Further, the optical element 15 guides the second light flux Lf2 including the first fluorescent light Lw2 from the observation target S irradiated with the first narrowband light to the second imaging element 522b.

[0357] As a result, the first imaging element 522a receives the first light flux Lf1 including the wideband reflected light Lw1 (while light within the wavelength band of the first fluorescent light Lw2 is partially, substantially, or completely suppressed), and the second imaging element 522b receives the second light flux Lf2 including the first fluorescent light Lw2. Then, under the control of the control device 90 (control section 94), the first imaging element 522a repeatedly outputs an image signal based on the wideband reflected light Lw1 (while light within the wavelength band of the first fluorescent light Lw2 is partially, substantially, or completely suppressed), and the second imaging element 522b repeatedly outputs an image signal based on the first fluorescent light Lw2.

[0358] Then, under the control of the control section 94, the image generation section 93 (specifically, the image processing section 931 (see Figure 7 )) generates a captured image (high-resolution color image) of the observation target S based on the wideband reflected light Lw1 based on the image signal output from the first imaging element 522a that has received the first light flux Lf1 including the wideband reflected light Lw1 (while light within the wavelength band of the first fluorescent light Lw2 is partially, substantially, or completely suppressed). Further, under the control of the control section 94, the image generation section 93 (image processing section 931) generates a captured image (high-sensitivity monochrome image) of the observation target S based on the first fluorescent light Lw2 based on the image signal output from the second imaging element 522b that has received the second light flux Lf2 including the first fluorescent light Lw2. The "high-resolution color image" mentioned here is a color image acquired by a high-resolution imaging element, and the "high-sensitivity monochrome image" is a monochrome image acquired by a high-sensitivity imaging element.

[0359] As described above, in this mode, within a common time frame, a normal light captured image that is a reflected image of visible light (white light) and a first fluorescent light captured image in which the first substance in the observation target S is emphasized, that is, the first fluorescent light emitted from the first substance of the observation target S excited by narrowband light are acquired. Therefore, the user can compare and observe the normal light captured image and the first fluorescent light captured image of the observation target S and observe a combined image (superimposed image) formed by these images via the display device 70 (see Figure 1A ).

[0360] Note that, in the example described above, the wideband light and the first narrowband light are emitted in a time-division manner, but the light source device 10 can also continuously emit the wideband light and / or the first narrowband light under the control of the control device 90 (control section 94).

[0361] In a case where the continuous emission of the wideband light is performed, the first imaging element 522a is continuously exposed to the wideband reflected light Lwl (while the light in the wavelength band of the first fluorescent light Lw2 is partially, substantially, or completely suppressed). Further, in a case where the continuous emission of the first narrowband light is performed, the second imaging element 522b is continuously exposed to the first fluorescent light Lw2. Thus, in these cases, the amount of charge accumulation in the imaging elements increases, a bright captured image can be acquired, an increase in noise due to gain adjustment can be suppressed, and a significant reduction in frame rate can be prevented.

[0362] <Second Mode>

[0363] The second mode of the present embodiment is an observation mode in which the wideband light and the second narrowband light are irradiated to the observation target S to acquire a captured image based on the wideband reflected light Lwl and the second fluorescent light Lw3 from the observation target S.

[0364] That is, the control device 90 (control section 94) controls the light source device 10 (the wideband light source 11 and the second narrowband light source 13), and the wideband light and the second narrowband light are emitted from the light source device 10 in time division, and the wideband light and the second narrowband light are emitted to the observation target S in time division. Note that, in this mode, the first narrowband light source 12 is placed in an off state, and the first narrowband light is not emitted from the light source device 10.

[0365] Then, the optical element 15 guides the first light flux Lf1 including the wideband reflected light Lwl (while the light in the wavelength band of the first fluorescent light Lw2 is partially, substantially, or completely suppressed) from the observation target S irradiated with the wideband light to the first imaging element 522a. Further, the optical element 15 guides the second light flux Lf2 including the second fluorescent light Lw3 from the observation target S irradiated with the second narrowband light to the second imaging element 522b.

[0366] As a result, the first imaging element 522a receives the first light flux Lf1 including the wideband reflected light Lwl (while the light in the wavelength band of the first fluorescent light Lw2 is partially, substantially, or completely suppressed), and the second imaging element 522b receives the second light flux Lf2 including the second fluorescent light Lw3.

[0367] Then, under the control of the control device 90 (control section 94), the first imaging element 522a repeatedly outputs an image signal based on the wideband reflected light Lwl (while the light in the wavelength band of the first fluorescent light Lw2 is partially, substantially, or completely suppressed), and the second imaging element 522b repeatedly outputs an image signal based on the second fluorescent light Lw3.

[0368] Then, under the control of the control section 94, the image generation section 93 (the image processing section 931) generates a captured image (a high-resolution color image) of the observation target S based on the broadband reflected light Lwl based on the image signal output from the first imaging element 522a that has received the first light flux Lf1 including the broadband reflected light Lwl (while light within the wavelength band of the first fluorescent light Lw2 is partially, substantially, or completely suppressed). Further, under the control of the control section 94, the image generation section 93 (the image processing section 931) generates a captured image (a high-sensitivity monochrome image) of the observation target S based on the second fluorescent light Lw3 based on the image signal output from the second imaging element 522b that has received the second light flux Lf2 including the second fluorescent light Lw3. The "high-resolution color image" mentioned here is a color image acquired by a high-resolution imaging element, and the "high-sensitivity monochrome image" is a monochrome image acquired by a high-sensitivity imaging element.

[0369] As described above, in this mode, within a common time frame, a normal light captured image that is a reflected image of visible light (white light) and a second fluorescent light captured image in which the second substance in the observation target S is emphasized, that is, fluorescent light emitted from the second substance of the observation target S excited by narrowband light are acquired. Therefore, the user can compare and observe the normal light captured image and the second fluorescent light captured image of the observation target S and observe a combined image (a superimposed image) formed by these images via the display device 70.

[0370] Note that, in the example described above, the broadband light and the second narrowband light are emitted in a time-division manner, but the light source device 10 can also continuously emit the broadband light and / or the second narrowband light under the control of the control device 90 (the control section 94).

[0371] In the case where continuous emission of the broadband light is performed, the first imaging element 522a is continuously exposed to the broadband reflected light Lwl (while light within the wavelength band of the first fluorescent light Lw2 is partially, substantially, or completely suppressed). Further, in the case where continuous emission of the second narrowband light is performed, the second imaging element 522b can be continuously exposed to the second fluorescent light Lw3. Therefore, in these cases, the amount of charge accumulation in the imaging element increases, a bright captured image can be acquired, an increase in noise due to gain adjustment can be suppressed, and a significant reduction in frame rate can be prevented.

[0372] <Third Mode>

[0373] The third mode of the present embodiment is an observation mode in which the observation target S is irradiated with the broadband light, the first narrowband light, and the second narrowband light to acquire captured images based on the broadband reflected light Lwl, the first fluorescent light Lw2, and the second fluorescent light Lw3 from the observation target S.

[0374] That is, the control device 90 (the control section 94) controls the light source device 10 (the wideband light source 11, the first narrowband light source 12, and the second narrowband light source 13), and emits the first narrowband light and the second narrowband light from the light source device 10 in a time-division manner while continuously emitting the wideband light from the light source device 10. As a result, the wideband light is continuously emitted to the observation target S, and the first narrowband light and the second narrowband light are emitted to the observation target S in a time-division manner.

[0375] Then, the optical element 15 continuously guides the first light flux Lf1 including the wideband reflected light Lw1 from the observation target S irradiated with the wideband light (while light within the wavelength band of the first fluorescent light Lw2 is partially, substantially, or completely suppressed) to the first imaging element 522a. In addition, the optical element 15 sequentially guides the second light flux Lf2 including the first fluorescent light Lw2 from the observation target S irradiated with the first narrowband light and the second light flux Lf2 including the second fluorescent light Lw3 from the observation target S irradiated with the second narrowband light to the second imaging element 522b.

[0376] As a result, the first imaging element 522a continuously receives the first light flux Lf1 including the wideband reflected light Lw1 (while light within the wavelength band of the first fluorescent light Lw2 is partially, substantially, or completely suppressed), and repeatedly outputs an image signal based on the wideband reflected light Lw1 under the control of the control device 90 (the control section 94).

[0377] On the other hand, the second imaging element 522b sequentially receives the second light flux Lf2 including the first fluorescent light Lw2 and the second light flux Lf2 including the second fluorescent light Lw3. Then, the second imaging element 522b sequentially and repeatedly outputs an image signal based on the first fluorescent light Lw2 and an image signal based on the second fluorescent light Lw3 under the control of the control device 90 (the control section 94).

[0378] Then, under the control of the control section 94, the image generation section 93 (image processing section 931) generates a captured image (high-resolution color image) of the observation target S based on the wide-band reflected light Lw1 based on the image signal output from the first imaging element 522a that has received the first light flux Lf1 including the wide-band reflected light Lw1 (while the light in the wavelength band of the first fluorescent light Lw2 is partially, substantially, or completely suppressed). Further, under the control of the control section 94, the image generation section 93 (image processing section 931) generates a captured image (high-sensitivity monochrome image) of the observation target S based on the first fluorescent light Lw2 based on the image signal output from the second imaging element 522b that has received the second light flux Lf2 including the first fluorescent light Lw2. Further, under the control of the control section 94, the image generation section 93 (image processing section 931) generates a captured image (high-sensitivity monochrome image) of the observation target S based on the second fluorescent light Lw3 based on the image signal output from the second imaging element 522b that has received the second light flux Lf2 including the second fluorescent light Lw3. The “high-resolution color image” mentioned here is a color image acquired by a high-resolution imaging element, and the “high-sensitivity monochrome image” is a monochrome image acquired by a high-sensitivity imaging element.

[0379] As described above, in this mode, within a common time frame, a normal light captured image that is a reflected image of visible light (white light), and a first fluorescent light captured image and a second fluorescent light captured image that are images in which the first substance and the second substance in the observation target S are emphasized, that is, the first substance and the second substance in the observation target S emit fluorescent light from excitation by narrow-band light. Therefore, the user can compare and observe the normal light captured image, the first fluorescent light captured image, and the second fluorescent light captured image of the observation target S, and can observe a combined image (superimposed image) formed by these images.

[0380] Note that, in the above example, the wide-band light is continuously emitted, but the light source device 10 can also repeatedly turn on and off the emission of the wide-band light under the control of the control device 90 (control section 94).

[0381] [Fifth Embodiment]

[0382] In the present embodiment, elements that are the same as or correspond to elements in the above-described first to fourth embodiments are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0383] Figure 20 is a diagram for explaining the types of light incident to the imaging elements (first imaging element 522a and second imaging element 522b) according to the fifth embodiment.

[0384] The camera head 50 (specifically, the imaging section 52) of the present embodiment includes a two-plate imaging module (see Figure 3and Figure 4 ), and includes a first imaging element 522a having a color filter CF and a second imaging element 522b having a color filter CF. Specifically, the color filter CF provided in the second imaging element 522b includes a filter through which a second fluorescent light Lw3 can pass in addition to the wideband reflected light Lwl and the first fluorescent light Lw2. On the other hand, the color filter CF provided in the first imaging element 522a transmits the wideband reflected light Lwl and the first fluorescent light Lw2 received by the first imaging element 522a (as described later), but can or can not transmit light in a wavelength band different from the wideband reflected light Lwl and the first fluorescent light Lw2 (for example, the second fluorescent light Lw3). The first imaging element 522a has relatively lower sensitivity and higher resolution (for example, 4K resolution) than the second imaging element 522b, and the second imaging element 522b has relatively higher sensitivity and lower resolution (for example, HD resolution) than the first imaging element 522a.

[0385] The light source device 10 (see Figure 1A ) emits light from at least one of the wideband light source 11, the first narrowband light source 12, and the second narrowband light source 13, and can irradiate the observation target S with at least one of the wideband light, the first narrowband light, and the second narrowband light.

[0386] Therefore, the observation light Lf from the observation target S can include the wideband reflected light Lwl which is reflected light as the wideband light, the first fluorescent light Lw2 emitted from the first substance excited by the first narrowband light, and the second fluorescent light Lw3 emitted from the second substance excited by the second narrowband light. Note that the wideband reflected light Lwl and the first fluorescent light Lw2 are light included in the first wavelength band, and the second fluorescent light Lw3 is light included in the second wavelength band outside the first wavelength band.

[0387] The observation light Lf incident on the optical element 15 is split by the optical element 15 into a first light flux Lfl and a second light flux Lf2. The optical element 15 of the present embodiment guides a portion of light included in the first wavelength band as the first light flux Lfl to the first imaging element 522a, and guides light included in the first wavelength band and a portion of light included in the second wavelength band as the second light flux Lf2 to the second imaging element 522b.

[0388] As described above, in the present embodiment, light in the first wavelength band in the observation light Lf is partially suppressed and light in the wavelength band of the second fluorescent light Lw3 is guided to the first imaging element 522a as the first light flux Lf1 which is partially, substantially or completely suppressed. That is, light including at least a part of the broadband reflected light Lw1 is guided to the first imaging element 522a as the first light flux Lf1. Further, the second light flux Lf2 in which light in the first wavelength band in the observation light Lf is partially suppressed is guided to the second imaging element 522b. That is, light including the broadband reflected light Lw1 and at least a part of the first fluorescent light Lw2 and the second fluorescent light Lw3 is guided to the second imaging element 522b as the second light flux Lf2.

[0389] The medical observation system 100 of the present embodiment having the above-described structure can acquire various captured images of the observation target S according to the following observation modes (first mode to third mode).

[0390] <First Mode>

[0391] The first mode of the present embodiment is an observation mode in which the broadband light and the first narrowband light are irradiated to the observation target S to acquire a captured image based on the broadband reflected light Lwl and the first fluorescent light Lw2 from the observation target S.

[0392] That is, the control device 90 (control section 94 (see Figure 7 )) controls the light source device 10 (broadband light source 11 and first narrowband light source 12 (see Figure 1A )), emits the broadband light and the first narrowband light from the light source device 10 in a time-division manner, and emits the broadband light and the first narrowband light to the observation target S in a time-division manner. Note that, in this mode, the second narrowband light source 13 is placed in an off state, and the second narrowband light is not emitted from the light source device 10.

[0393] Then, the optical element 15 sequentially guides the first light flux Lfl including the broadband reflected light Lwl from the observation target S irradiated with the broadband light and the first light flux Lfl including the first fluorescent light Lw2 from the observation target S irradiated with the first narrowband light to the first imaging element 522a. Further, the optical element 15 sequentially guides the second light flux Lf2 including the broadband reflected light Lwl from the observation target S irradiated with the broadband light and the second light flux Lf2 including the first fluorescent light Lw2 from the observation target S irradiated with the first narrowband light to the second imaging element 522b.

[0394] As a result, the first imaging element 522a sequentially receives the first light flux Lf1 including the broadband reflected light Lw1 and the first light flux Lf1 including the first fluorescent light Lw2. Further, the second imaging element 522b sequentially receives the second light flux Lf2 including the broadband reflected light Lw1 and the second light flux Lf2 including the first fluorescent light Lw2.

[0395] Then, the first imaging element 522a sequentially and repeatedly outputs an image signal based on the wideband reflected light Lwl and an image signal based on the first fluorescent light Lw2 under the control of the control device 90 (the control section 94 (see Figure 7 )). However, in the present example, these image signals output from the first imaging element 522a are not used for generating a captured image.

[0396] Further, the second imaging element 522b sequentially and repeatedly outputs an image signal based on the wideband reflected light Lwl and an image signal based on the first fluorescent light Lw2 under the control of the control device 90 (the control section 94).

[0397] Then, under the control of the control section 94, the image generation section 93 (concretely, the image processing section 931 (see Figure 7 )) generates a captured image (a high-sensitivity color image) of the observation target S based on the wideband reflected light Lwl based on the image signal output from the second imaging element 522b that has received the second light flux Lf2 including the wideband reflected light Lwl. Further, under the control of the control section 94, the image generation section 93 (the image processing section 931) generates a captured image (a high-sensitivity color image) of the observation target S based on the first fluorescent light Lw2 based on the image signal output from the second imaging element 522b that has received the second light flux Lf2 including the first fluorescent light Lw2. The "high-sensitivity color image" mentioned here is a color image acquired by a high-sensitivity imaging element.

[0398] As described above, in this mode, within a common time frame, a normal light captured image that is a reflected image of visible light (white light) and a first fluorescent light captured image in which the first substance in the observation target S is emphasized, that is, the first fluorescent light emitted from the first substance in the observation target S excited by narrowband light are acquired. Therefore, the user can compare and observe the normal light captured image and the first fluorescent light captured image of the observation target S and observe a combined image (a superimposed image) formed by these images via the display device 70 (see Figure 1A ).

[0399] Note that, in the above example, the image signals output from the second imaging element 522b are used for generating captured images based on the wideband reflected light Lwl and the first fluorescent light Lw2, but the image signals output from the first imaging element 522a can be used.

[0400] That is, the control section 94 can control the imaging section 52 (imaging element 522) and the image generation section 93 to generate an image based on the broadband reflected light Lwl based on one or both of an image signal output from the first imaging element 522a that has received the first light flux Lf1 including the broadband reflected light Lwl and an image signal output from the second imaging element 522b that has received the second light flux Lf2 including the broadband reflected light Lwl.

[0401] For example, in a case where resolution is prioritized over sensitivity, a captured image based on the broadband reflected light Lwl (high-resolution color image) can be generated based on the image signal output from the first imaging element 522a. On the other hand, in a case where sensitivity is prioritized over resolution, a captured image based on the broadband reflected light Lwl (high-sensitivity color image) can be generated based on the image signal output from the second imaging element 522b. The “high-resolution color image” mentioned here is a color image acquired by a high-resolution imaging element, and the “high-sensitivity color image” is a color image acquired by a high-sensitivity imaging element.

[0402] As an example, in a case where the amount of the broadband reflected light Lwl is sufficient for the first imaging element 522a to perform imaging (light reception), a captured image based on the broadband reflected light Lwl can be generated based on the image signal output from the first imaging element 522a. On the other hand, in a case where the amount of the broadband reflected light Lwl is insufficient for the first imaging element 522a to perform imaging (light reception), a captured image based on the broadband reflected light Lwl can be generated based on the image signal output from the second imaging element 522b. For example, in a case where it is not desirable to irradiate the observation target S with a large amount of broadband light, a captured image based on the broadband reflected light Lwl can be generated based on the image signal output from the second imaging element 522b while suppressing the amount of light emission of the broadband light in the light source device 10.

[0403] Furthermore, a captured image based on the broadband reflected light Lwl can be generated based on the image signal output from the first imaging element 522a and the image signal output from the second imaging element 522b. For example, the image generation section 93 (image processing section 931) can use an arbitrary image combination technique to generate a high-quality “captured image based on the broadband reflected light Lwl” based on the image signals output from the first imaging element 522a and the second imaging element 522b.

[0404] The control section 94 can determine which one or both of the image signal output from the first imaging element 522a and the image signal output from the second imaging element 522b is used to generate an image based on the broadband reflected light Lwl based on an instruction from a user received via the input section 95.

[0405] <Second Mode>

[0406] The second mode of the present embodiment is an observation mode in which the wideband light and the second narrowband light are irradiated to the observation target S to acquire a captured image based on the wideband reflected light Lwl and the second fluorescent light Lw3 from the observation target S.

[0407] That is, the control device 90 (the control section 94) controls the light source device 10 (the wideband light source 11 and the second narrowband light source 13), and time-divisionally emits the wideband light and the second narrowband light from the light source device 10 to time-divisionally emit the wideband light and the second narrowband light to the observation target S. Note that, in this mode, the first narrowband light source 12 is placed in an off state, and the first narrowband light is not emitted from the light source device 10.

[0408] Then, the optical element 15 guides the first light flux Lf1 including the wideband reflected light Lwl from the observation target S irradiated with the wideband light to the first imaging element 522a. Further, the optical element 15 guides the second light flux Lf2 including the wideband reflected light Lwl from the observation target S irradiated with the wideband light and the second light flux Lf2 including the second fluorescent light Lw3 from the observation target S irradiated with the second narrowband light to the second imaging element 522b in order.

[0409] As a result, the first imaging element 522a receives the first light flux Lf1 including the wideband reflected light Lwl under the control of the control device 90 (the control section 94), and repeatedly outputs an image signal based on the wideband reflected light Lwl. Further, the second imaging element 522b receives the second light flux Lf2 including the wideband reflected light Lwl and the second light flux Lf2 including the second fluorescent light Lw3 in order. Then, the second imaging element 522b outputs an image signal based on the wideband reflected light Lwl and an image signal based on the second fluorescent light Lw3 in order and repeatedly under the control of the control device 90 (the control section 94).

[0410] Then, under the control of the control section 94, the image generation section 93 (image processing section 931) generates a captured image (high-resolution color image) of the observation target S based on the broadband reflected light Lwl based on the image signal output from the first imaging element 522a that has received the first light flux Lf1 including the broadband reflected light Lwl. Further, under the control of the control section 94, the image generation section 93 (image processing section 931) generates a captured image (high-sensitivity image) of the observation target S based on the second fluorescent light Lw3 based on the image signal output from the second imaging element 522b that has received the second light flux Lf2 including the second fluorescent light Lw3. The "high-resolution color image" mentioned here is a color image acquired by a high-resolution imaging element, and the "high-sensitivity image" is an image acquired by a high-sensitivity imaging element. The image based on the second fluorescent light Lw3 generated in this way is based on the image signal output from the second imaging element 522b with the color filter CF, and thus can be called a color image, but can also be called a monochrome image because it does not substantially include color information.

[0411] As described above, in this mode, within a common time frame, a normal light captured image that is a reflected image of visible light (white light) and a second fluorescent light captured image in which the second substance of the observation target S is emphasized, that is, the second fluorescent light emitted from the second substance of the observation target S excited by the narrowband light are acquired. Therefore, the user can compare and observe the normal light captured image and the second fluorescent light captured image of the observation target S and observe a combined image (superimposed image) formed by these images via the display device 70.

[0412] Note that, in the example described above, the broadband light and the second narrowband light are emitted in a time-division manner, but the light source device 10 can also continuously emit the second narrowband light while repeatedly turning on and off the emission of the broadband light under the control of the control device 90 (control section 94).

[0413] In this case, the light source device 10 (broadband light source 11) emits the broadband light so that the broadband reflected light Lwl is exposed to the first imaging element 522a in the broadband light image frame of the first imaging element 522a. On the other hand, the light source device 10 (broadband light source 11) stops the emission of the broadband light in the second fluorescent light image frame of the second imaging element 522b so that the broadband reflected light Lwl is not exposed to the second imaging element 522b. As a result, the image signal of the broadband light image frame can be appropriately output from the first imaging element 522a, and the image signal of the second fluorescent light image frame can be appropriately output from the second imaging element 522b.

[0414] Note that in this mode, the image signal of the wideband light image frame is also output from the second imaging element 522b, but in the above example, the wideband light image frame from the second imaging element 522b is not used for generating the captured image. In the above example, the image data of the wideband light image frame that is not used for generating the captured image is repeatedly output as the image signal from the second imaging element 522b, but the image data of the wideband light image frame that is not used for generating the captured image can not be output as the image signal from the second imaging element 522b.

[0415] Further, in the above example, the captured image based on the wideband reflected light Lwl can be generated based on the image signal of the wideband light image frame from the second imaging element 522b that is not used for generating the captured image. For example, the captured image based on the wideband reflected light Lwl can be generated based on the image signal of the wideband light image frame from both the first imaging element 522a and the second imaging element 522b.

[0416] The captured image generated in this way can or can not be used for generating the output image.

[0417] The captured image that is not used for generating the output image can be used for any purpose (for example, correction processing regarding the brightness of the output image or adjustment processing regarding the focus position).

[0418] <Third Mode>

[0419] The third mode of the present embodiment is an observation mode in which the wideband light, the first narrowband light, and the second narrowband light are irradiated to the observation target S to acquire the captured image based on the wideband reflected light Lwl, the first fluorescent light Lw2, and the second fluorescent light Lw3 from the observation target S.

[0420] That is, the control device 90 (control section 94) controls the light source device 10 (wideband light source 11, first narrowband light source 12, and second narrowband light source 13), and the wideband light, the first narrowband light, and the second narrowband light are emitted from the light source device 10 in a time-division manner. As a result, the wideband light, the first narrowband light, and the second narrowband light are emitted to the observation target S in a time-division manner.

[0421] Then, the optical element 15 sequentially guides the first light flux Lfl including the broadband reflected light Lwl from the observation target S irradiated with the broadband light and the first light flux Lfl including the first fluorescent light Lw2 from the observation target S irradiated with the first narrowband light to the first imaging element 522a. Further, the optical element 15 sequentially guides the second light flux Lf2 including the broadband reflected light Lwl from the observation target S irradiated with the broadband light, the second light flux Lf2 including the first fluorescent light Lw2 from the observation target S irradiated with the first narrowband light, and the second light flux Lf2 including the second fluorescent light Lw3 from the observation target S irradiated with the second narrowband light to the second imaging element 522b.

[0422] As a result, the first imaging element 522a sequentially receives the first light flux Lfl including the broadband reflected light Lwl and the first light flux Lfl including the first fluorescent light Lw2. Then, the first imaging element 522a sequentially and repeatedly outputs an image signal based on the broadband reflected light Lwl and an image signal based on the first fluorescent light Lw2 under the control of the control device 90 (control section 94).

[0423] On the other hand, the second imaging element 522b sequentially receives the second light flux Lf2 including the broadband reflected light Lwl, the second light flux Lf2 including the first fluorescent light Lw2, and the second light flux Lf2 including the second fluorescent light Lw3. Then, the second imaging element 522b sequentially and repeatedly outputs an image signal based on the broadband reflected light Lwl, an image signal based on the first fluorescent light Lw2, and an image signal based on the second fluorescent light Lw3 under the control of the control device 90 (control section 94).

[0424] Then, under the control of the control section 94, the image generation section 93 (the image processing section 931) generates a captured image (a high-resolution color image) of the observation target S based on the broadband reflected light Lwl based on the image signal output from the first imaging element 522a that has received the first light flux Lfl including the broadband reflected light Lwl. Further, under the control of the control section 94, the image generation section 93 (the image processing section 931) generates a captured image (a high-sensitivity color image) of the observation target S based on the first fluorescent light Lw2 based on the image signal output from the second imaging element 522b that has received the second light flux Lf2 including the first fluorescent light Lw2. Further, under the control of the control section 94, the image generation section 93 (the image processing section 931) generates a captured image (a high-sensitivity image) of the observation target S based on the second fluorescent light Lw3 based on the image signal output from the second imaging element 522b that has received the second light flux Lf2 including the second fluorescent light Lw3. The "high-resolution color image" mentioned here is a color image acquired by a high-resolution imaging element, the "high-sensitivity color image" is a color image acquired by a high-sensitivity imaging element, and the "high-sensitivity image" is an image acquired by a high-sensitivity imaging element.

[0425] As described above, in this mode, within a common time frame, a normal light captured image that is a reflected image of visible light (white light), and a first fluorescent light captured image and a second fluorescent light captured image that are images in which the first substance and the second substance in the observation target S are emphasized, that is, fluorescent light emitted from the first substance and the second substance in the observation target S excited by narrowband light, are acquired. Therefore, the user can compare and observe the normal light captured image, the first fluorescent light captured image, and the second fluorescent light captured image of the observation target S, and can observe a combined image (a superimposed image) formed by these images.

[0426] In addition, in this mode, the image signal of the first fluorescent light image frame is also output from the first imaging element 522a, and the image signal of the broadband light image frame is also output from the second imaging element 522b. However, in the above example, these image frames are not used for generating captured images. In the above example, the image data of these image frames that are not used for generating captured images are also repeatedly output as image signals from the imaging elements (the first imaging element 522a and the second imaging element 522b), but the image data of the image frames that are not used for generating captured images can not be output as image signals from the imaging elements.

[0427] In addition, in the above example, these image frames that are not used for generating captured images (that is, the first fluorescent light image frame from the first imaging element 522a and the broadband light image frame from the second imaging element 522b) can also be used to generate captured images.

[0428] That is, a captured image based on the first fluorescent light Lw2 can be generated based on the image signal of the first fluorescent light image frame from the first imaging element 522a. For example, a captured image based on the first fluorescent light Lw2 can be generated based on the image signal of the first fluorescent light image frame from both the first imaging element 522a and the second imaging element 522b.

[0429] In addition, a captured image based on the wideband reflected light Lw1 can be generated based on the image signal of the wideband light image frame from the second imaging element 522b. For example, a captured image based on the wideband reflected light Lw1 can be generated based on the image signal of the wideband light image frame from both the first imaging element 522a and the second imaging element 522b.

[0430] The captured image generated in this way can or can not be used to generate an output image.

[0431] The captured image that is not used to generate an output image can be used for any purpose (for example, correction processing regarding the brightness of the output image or adjustment processing regarding the focus position).

[0432] [Sixth Embodiment]

[0433] In the present embodiment, elements that are the same as or correspond to the elements in the above-described first to fifth embodiments are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0434] Figure 21 is a diagram for explaining the types of light incident to the imaging elements (first imaging element 522a, second imaging element 522b, third imaging element 522c) according to the sixth embodiment.

[0435] The camera head 50 (specifically, the imaging section 52) of the present embodiment includes a three-plate type imaging module (see Figure 5 and Figure 6 ), and includes the first imaging element 522a having the color filter CF, and the second imaging element 522b and the third imaging element 522c not having the color filter CF.

[0436] The color filter CF provided in the first imaging element 522a of the present embodiment transmits the wide-band reflected light Lwl and the first fluorescent light Lw2 (as described later) received by the first imaging element 522a, but can or can not transmit light (for example, the second fluorescent light Lw3) within a wavelength band different from the wide-band reflected light Lwl and the first fluorescent light Lw2. Note that the second imaging element 522b and the third imaging element 522c of the present example do not include the color filter CF, but the second imaging element 522b can include a color filter CF capable of transmitting the wide-band reflected light Lwl and the first fluorescent light Lw2, and the third imaging element 522c can include a color filter CF capable of transmitting the second fluorescent light Lw3.

[0437] The first imaging element 522a has relatively lower sensitivity and higher resolution (for example, 4K resolution) than the second imaging element 522b and the third imaging element 522c, and the second imaging element 522b and the third imaging element 522c have relatively higher sensitivity and lower resolution (for example, HD resolution) than the first imaging element 522a. The second imaging element 522b and the third imaging element 522c can have the same or different characteristics from each other. As described above, the resolution of the first imaging element 522a is higher than the resolution of the second imaging element 522b and the third imaging element 522c, but the sensitivity of the second imaging element 522b and the third imaging element 522c is higher than the sensitivity of the first imaging element 522a.

[0438] However, the resolution and sensitivity of the first imaging element 522a to the third imaging element 522c are not limited thereto, and the relationship between the resolution and sensitivity of the first imaging element 522a to the third imaging element 522c is not limited thereto.

[0439] The light source device 10 (see Figure 1A ) emits light from at least one of the wide-band light source 11, the first narrow-band light source 12, and the second narrow-band light source 13, and can irradiate the observation target S with at least one of the wide-band light, the first narrow-band light, and the second narrow-band light. Therefore, the observation light Lf from the observation target S can include the wide-band reflected light Lwl which is reflected light of the wide-band light, the first fluorescent light Lw2 emitted from the first substance excited by the first narrow-band light, and the second fluorescent light Lw3 emitted from the second substance excited by the second narrow-band light. Note that the wide-band reflected light Lwl and the first fluorescent light Lw2 are light included within the first wavelength band, and the second fluorescent light Lw3 is light included within the second wavelength band outside the first wavelength band.

[0440] The observation light Lf incident on the optical element 15 is split by the optical element 15 into a first light flux Lf1, a second light flux Lf2, and a third light flux Lf3. The optical element 15 of the present embodiment guides a portion of light included in the first wavelength band as the first light flux Lf1 to the first imaging element 522a, guides a portion of light included in the first wavelength band as the second light flux Lf2 to the second imaging element 522b, and guides light included in the second wavelength band as the third light flux Lf3 to the third imaging element 522c.

[0441] As described above, in the present embodiment, the first light flux Lf1 in which a portion of light within the first wavelength band in the observation light Lf is suppressed and light within the wavelength band of the second fluorescent light Lw3 is partially, substantially, or entirely suppressed is guided by the optical element 15 to the first imaging element 522a. That is, light including at least a portion of the broadband reflected light Lwl is guided to the first imaging element 522a as the first light flux Lf1. Further, the second light flux Lf2 in which light within the first wavelength band is partially suppressed and light within the wavelength band of the second fluorescent light Lw3 is partially, substantially, or entirely suppressed in the observation light Lf is guided to the second imaging element 522b. That is, light including at least a portion of the broadband reflected light Lwl and the first fluorescent light Lw2 is guided to the second imaging element 522b as the second light flux Lf2. Further, the third light flux Lf3 in which light of the first wavelength band in the observation light Lf is partially, substantially, or entirely suppressed is guided to the third imaging element 522c. That is, light including at least the second fluorescent light Lw3 is guided to the third imaging element 522c as the third light flux Lf3.

[0442] The medical observation system 100 of the present embodiment having the above-described structure can acquire various captured images of the observation target S according to the following observation modes (first mode and second mode).

[0443] <First Mode>

[0444] The first mode of the present embodiment is an observation mode in which the broadband light and the first narrowband light are irradiated to the observation target S to acquire a captured image based on the broadband reflected light Lwl and the first fluorescent light Lw2 from the observation target S.

[0445] That is, the control device 90 (control section 94 (see Figure 7 ) controls the light source device 10 (broadband light source 11 and first narrowband light source 12 (see Figure 1A)) emits the broadband light and the first narrow-band light in a time-division manner from the light source device 10, and emits the broadband light and the first narrow-band light in a time-division manner toward the observation target S. Note that, in this mode, the second narrow-band light source 13 is placed in an off state, and the second narrow-band light is not emitted from the light source device 10.

[0446] Then, the optical element 15 sequentially guides the first light flux Lfl including the broadband reflected light Lwl from the observation target S irradiated with the broadband light and the first light flux Lfl including the first fluorescent light Lw2 from the observation target S irradiated with the first narrow-band light to the first imaging element 522a. As a result, the first imaging element 522a sequentially receives the first light flux Lfl including the broadband reflected light Lwl and the first light flux Lfl including the first fluorescent light Lw2.

[0447] Further, the optical element 15 sequentially guides the second light flux Lf2 including the broadband reflected light Lwl from the observation target S irradiated with the broadband light and the second light flux Lf2 including the first fluorescent light Lw2 from the observation target S irradiated with the first narrow-band light to the second imaging element 522b. As a result, the second imaging element 522b sequentially receives the second light flux Lf2 including the broadband reflected light Lwl and the second light flux Lf2 including the first fluorescent light Lw2.

[0448] Then, the first imaging element 522a and the second imaging element 522b each output the image signal based on the broadband reflected light Lwl and the image signal based on the first fluorescent light Lw2 sequentially and repeatedly under the control of the control device 90 (control section 94 (see Figure 7 ).

[0449] Then, under the control of the control section 94, the image generation section 93 (specifically, the image processing section 931 (see Figure 7 ) generates a captured image (high-resolution color image) of the observation target S based on the broadband reflected light Lwl from the image signal based on the broadband reflected light Lwl output from the first imaging element 522a. Further, under the control of the control section 94, the image generation section 93 (image processing section 931) generates a captured image (high-sensitivity monochrome image) of the observation target S based on the first fluorescent light Lw2 from the image signal based on the first fluorescent light Lw2 output from the second imaging element 522b. The "high-resolution color image" mentioned here is a color image acquired by a high-resolution imaging element, and the "high-sensitivity monochrome image" is a monochrome image acquired by a high-sensitivity imaging element.

[0450] As described above, in this mode, a normal light capture image that is a reflected image of visible light (white light) and a first fluorescent light capture image in which a first substance in the observation target S is emphasized, that is, fluorescent light emitted from the first substance of the observation target S excited by narrowband light, are acquired within a common time frame. Therefore, the user can compare and observe the normal light capture image and the first fluorescent light capture image of the observation target S and observe a combined image (superimposed image) formed by these images via the display device 70 (see Fig. 6). Figure 1A

[0451] Note that, in this mode, image signals of the first fluorescent light image frames are also output from the first imaging element 522a, and image signals of the wideband light image frames are also output from the second imaging element 522b. However, in the above example, these image frames are not used for generating the capture images. In the above example, the image data of these image frames that are not used for generating the capture images are also repeatedly output as image signals from the imaging elements (the first imaging element 522a and the second imaging element 522b), but the image data of the image frames that are not used for generating the capture images can not be output as image signals from the imaging elements.

[0452] Further, in the above example, these image frames that are not used for generating the capture images (that is, the first fluorescent light image frames from the first imaging element 522a and the wideband light image frames from the second imaging element 522b) can also be used to generate the capture images.

[0453] That is, a capture image based on the first fluorescent light Lw2 can be generated based on the image signals of the first fluorescent light image frames from the first imaging element 522a. For example, a capture image based on the first fluorescent light Lw2 can be generated based on the image signals of the first fluorescent light image frames from both the first imaging element 522a and the second imaging element 522b.

[0454] Further, a capture image based on the wideband reflected light Lw1 can be generated based on the image signals of the wideband light image frames from the second imaging element 522b. That is, a capture image based on the wideband reflected light Lw1 can be generated based on the image signals of the wideband light image frames from both the first imaging element 522a and the second imaging element 522b.

[0455] The capture images generated in this way can or can not be used to generate the output images.

[0456] The capture images that are not used to generate the output images can be used for any purpose (for example, correction processing regarding the brightness of the output images or processing regarding adjustment of the focal position).

[0457] <Second Mode>

[0458] ​The second mode of the present embodiment is an observation mode in which the wideband light and the second narrowband light are irradiated to the observation target S to acquire a captured image of the observation target S based on the wideband reflected light Lwl and the second fluorescent light Lw3 from the observation target S.

[0459] That is, the control device 90 (the control section 94) controls the light source device 10 (the wideband light source 11 and the second narrowband light source 13) to continuously emit the wideband light and the second narrowband light from the light source device 10 to continuously irradiate the observation target S with the wideband light and the second narrowband light. Note that, in this mode, the first narrowband light source 12 is placed in an off state, and the first narrowband light is not emitted from the light source device 10.

[0460] Then, the optical element 15 continuously guides the first light flux Lfl including the wideband reflected light Lwl from the observation target S irradiated with the wideband light to the first imaging element 522a, and continuously guides the second light flux Lf2 including the wideband reflected light Lwl to the second imaging element 522b. Further, the optical element 15 continuously guides the third light flux Lf3 including the second fluorescent light Lw3 from the observation target S irradiated with the second narrowband light to the third imaging element 522c.

[0461] As a result, the first imaging element 522a continuously receives the first light flux Lfl including the wideband reflected light Lwl, and the second imaging element 522b continuously receives the second light flux Lf2 including the wideband reflected light Lwl. Further, the third imaging element 522c continuously receives the third light flux Lf3 including the second fluorescent light Lw3.

[0462] Then, under the control of the control device 90 (the control section 94), the first imaging element 522a and the second imaging element 522b continuously repeatedly output the image signals based on the wideband reflected light Lwl, and the third imaging element 522c continuously repeatedly outputs the image signals based on the second fluorescent light Lw3.

[0463] Then, under the control of the control section 94, the image generation section 93 (the image processing section 931) generates a captured image (a high-resolution color image) of the observation target S based on the wideband reflected light Lwl from the image signals based on the wideband reflected light Lwl output from the first imaging element 522a. Further, under the control of the control section 94, the image generation section 93 (the image processing section 931) generates a captured image (a high-sensitivity monochrome image) of the observation target S based on the second fluorescent light Lw3 from the image signals based on the second fluorescent light Lw3 output from the third imaging element 522c. The "high-resolution color image" mentioned here is a color image acquired by a high-resolution imaging element, and the "high-sensitivity monochrome image" is a monochrome image acquired by a high-sensitivity imaging element.

[0464] As described above, in this mode, the normal light-captured image that is a reflected image of visible light (white light) and the second fluorescent-captured image in which the second substance in the observation target S is emphasized, that is, the second fluorescent light emitted from the second substance in the observation target S excited by the narrow-band light are acquired within a common time frame. Therefore, the user can compare and observe the normal light-captured image and the second fluorescent-captured image of the observation target S and observe a combined image (superimposed image) formed by these images via the display device 70.

[0465] Note that, in the above example, the wide-band light and the second narrow-band light are continuously emitted from the light source device 10, but the light source device 10 can also turn off the emission of the wide-band light and the second narrow-band light each at the middle under the control of the control device 90 (control section 94). For example, the light source device 10 can repeatedly turn on and off the emission of the wide-band light and the second narrow-band light, and can emit the wide-band light and the second narrow-band light in a time-division manner.

[0466] However, by continuously emitting the wide-band light and the second narrow-band light by the light source device 10, the first imaging element 522a can continuously receive the wide-band reflected light Lw1, and the third imaging element 522c can continuously receive the second fluorescent light Lw3. As a result, the amount of charge accumulation in the imaging elements increases, bright captured images can be acquired, an increase in noise due to gain adjustment can be suppressed, and a large decrease in frame rate can be prevented.

[0467] Note that, in this mode, the image signal of the wide-band light image frame is also output from the second imaging element 522b, but in the above example, the wide-band light image frame from the second imaging element 522b is not used to generate the captured image. In the above example, the image data of the wide-band light image frame that is not used to generate the captured image is repeatedly output as an image signal from the second imaging element 522b, but the image data of the wide-band light image frame that is not used to generate the captured image can not be output as an image signal from the second imaging element 522b.

[0468] Further, in the above example, the captured image based on the wide-band reflected light Lw1 can be generated based on the image signal of the wide-band light image frame that is not used to generate the captured image from the second imaging element 522b. That is, the captured image based on the wide-band reflected light Lw1 can be generated based on the image signal of the wide-band light image frame from both the first imaging element 522a and the second imaging element 522b.

[0469] The captured image generated in this way can or can not be used to generate the output image.

[0470] The captured image that is not used to generate the output image can be used for any purpose (for example, correction processing regarding the brightness of the output image or adjustment processing regarding the focus position).

[0471] [Seventh Embodiment]

[0472] In the present embodiment, the same reference numerals are affixed to portions common to the above-described first to sixth embodiments, and detailed description thereof is omitted.

[0473] The imaging elements (first imaging element 522a, second imaging element 522b, third imaging element 522c) of the seventh embodiment have the same structure as the imaging elements (refer to Figure 21 ) of the above-described sixth embodiment.

[0474] That is, the camera head 50 (specifically, the imaging section 52) of the present embodiment includes a three-plate type imaging module (see Figure 5 and Figure 6 ), and includes the first imaging element 522a having the color filter CF, and the second imaging element 522b and the third imaging element 522c not having the color filter CF.

[0475] The color filter CF provided in the first imaging element 522a of the present embodiment transmits the wideband reflected light Lw1 and the first fluorescent light Lw2 (as described later) received by the first imaging element 522a, but can or can not transmit light (for example, the second fluorescent light Lw3) in a wavelength band different from the wideband reflected light Lw1 and the first fluorescent light Lw2. Note that the second imaging element 522b and the third imaging element 522c of the present example do not include the color filter CF, but the second imaging element 522b can include a color filter CF capable of transmitting the wideband reflected light Lw1 and the first fluorescent light Lw2, and the third imaging element 522c can include a color filter CF capable of transmitting the second fluorescent light Lw3.

[0476] The first imaging element 522a has relatively lower sensitivity and higher resolution (for example, 4K resolution) than the second imaging element 522b and the third imaging element 522c, and the second imaging element 522b and the third imaging element 522c have relatively higher sensitivity and lower resolution (for example, HD resolution) than the first imaging element 522a. The second imaging element 522b and the third imaging element 522c can have the same or different characteristics from each other. As described above, the resolution of the first imaging element 522a is higher than the resolution of the second imaging element 522b and the third imaging element 522c, but the sensitivity of the second imaging element 522b and the third imaging element 522c is higher than the sensitivity of the first imaging element 522a.

[0477] However, the resolution and sensitivity of the first imaging element 522a to the third imaging element 522c are not limited thereto, and the relationship between the resolution and sensitivity of the first imaging element 522a to the third imaging element 522c is not limited thereto.

[0478] The light source device 10 (see Figure 1A ) emits light from at least one of the broadband light source 11, the first narrow-band light source 12, and the second narrow-band light source 13, and can irradiate the observation target S with at least one of the broadband light, the first narrow-band light, and the second narrow-band light. Thus, the observation light Lf from the observation target S can include the broadband reflected light Lwl that is the reflected light of the broadband light, the first fluorescent light Lw2 emitted from the first substance excited by the first narrow-band light, and the second fluorescent light Lw3 emitted from the second substance excited by the second narrow-band light. Note that the broadband reflected light Lwl and the first fluorescent light Lw2 are light included in the first wavelength band, and the second fluorescent light Lw3 is light included in the second wavelength band outside the first wavelength band.

[0479] The observation light Lf incident on the optical element 15 is split by the optical element 15 into a first light flux Lf1, a second light flux Lf2, and a third light flux Lf3. The optical element 15 of the present embodiment guides a part of the light included in the first wavelength band as the first light flux Lf1 to the first imaging element 522a, guides a part of the light included in the first wavelength band as the second light flux Lf2 to the second imaging element 522b, and guides the light included in the second wavelength band as the third light flux Lf3 to the third imaging element 522c.

[0480] As described above, in the present embodiment, the first light flux Lf1 in which a part of the light in the first wavelength band in the observation light Lf is suppressed and the light in the wavelength band of the second fluorescent light Lw3 is partially, substantially, or entirely suppressed is guided to the first imaging element 522a by the optical element 15. That is, the light including at least a part of the broadband reflected light Lwl is guided to the first imaging element 522a as the first light flux Lf1. Further, the second light flux Lf2 in which the light in the first wavelength band is partially suppressed and the light in the wavelength band of the second fluorescent light Lw3 is partially, substantially, or entirely suppressed in the observation light Lf is guided to the second imaging element 522b. That is, the light including at least a part of the broadband reflected light Lwl and the first fluorescent light Lw2 is guided to the second imaging element 522b as the second light flux Lf2. Further, the third light flux Lf3 in which the light in the first wavelength band in the observation light Lf is partially, substantially, or entirely suppressed is guided to the third imaging element 522c. That is, the light including at least the second fluorescent light Lw3 is guided to the third imaging element 522c as the third light flux Lf3.

[0481] The medical observation system 100 of the present embodiment having the above-described structure can acquire various captured images of the observation target S according to the following observation modes (first mode to third mode).

[0482] <First mode and second mode>

[0483] The first mode and the second mode of the present embodiment are executed similarly to the first mode and the second mode of the sixth embodiment described above.

[0484] Therefore, in the first mode, the wideband light and the first narrowband light are emitted by the light source device 10 in a time-division manner, and the wideband reflected light Lwl and the first fluorescent light Lw2 are received by the first imaging element 522a and the second imaging element 522b in a time-division manner. Further, in the second mode, the wideband light and the second narrowband light are continuously emitted by the light source device 10, the wideband reflected light Lwl is continuously received by the first imaging element 522a and the second imaging element 522b, and the second fluorescent light Lw3 is continuously received by the third imaging element 522c.

[0485] <Third Mode>

[0486] The third mode of the present embodiment is an observation mode in which the wideband light, the first narrowband light, and the second narrowband light are irradiated to the observation target S to acquire captured images based on the wideband reflected light Lwl, the first fluorescent light Lw2, and the second fluorescent light Lw3 from the observation target S.

[0487] That is, the control device 90 (control section 94) controls the light source device 10 (wideband light source 11, first narrowband light source 12, and second narrowband light source 13) to emit the wideband light and the first narrowband light in a time-division manner from the light source device 10, and to continuously emit the second narrowband light. As a result, the wideband light and the first narrowband light are emitted to the observation target S in a time-division manner, and the second narrowband light is continuously emitted to the observation target S.

[0488] Then, the optical element 15 sequentially guides the first light flux Lfl including the wideband reflected light Lwl from the observation target S irradiated with the wideband light and the first light flux Lfl including the first fluorescent light Lw2 from the observation target S irradiated with the first narrowband light to the first imaging element 522a. Further, the optical element 15 sequentially guides the second light flux Lf2 including the wideband reflected light Lwl from the observation target S irradiated with the wideband light and the second light flux Lf2 including the first fluorescent light Lw2 from the observation target S irradiated with the first narrowband light to the second imaging element 522b. Further, the optical element 15 continuously guides the third light flux Lf3 including the second fluorescent light Lw3 from the observation target S irradiated with the second narrowband light to the third imaging element 522c.

[0489] As a result, the first imaging element 522a sequentially receives the first light flux Lf1 including the broadband reflected light Lw1 and the first light flux Lf1 including the first fluorescent light Lw2. Further, the second imaging element 522b sequentially receives the second light flux Lf2 including the broadband reflected light Lw1 and the second light flux Lf2 including the first fluorescent light Lw2. Further, the third imaging element 522c continuously receives the third light flux Lf3 including the second fluorescent light Lw3.

[0490] Then, the first imaging element 522a and the second imaging element 522b each output the image signal based on the broadband reflected light Lw1 and the image signal based on the first fluorescent light Lw2 sequentially and repeatedly under the control of the control device 90 (control section 94). Further, the second imaging element 522b repeatedly outputs the image signal based on the second fluorescent light Lw3 continuously under the control of the control device 90 (control section 94).

[0491] Then, under the control of the control section 94, the image generation section 93 (image processing section 931) generates a captured image (high-resolution color image) of the observation target S based on the broadband reflected light Lw1 from the image signal based on the broadband reflected light Lw1 output from the first imaging element 522a. Further, under the control of the control section 94, the image generation section 93 (image processing section 931) generates a captured image (high-sensitivity monochrome image) of the observation target S based on the first fluorescent light Lw2 from the image signal based on the first fluorescent light Lw2 output from the second imaging element 522b. Further, under the control of the control section 94, the image generation section 93 (image processing section 931) generates a captured image (high-sensitivity monochrome image) of the observation target S based on the second fluorescent light Lw3 from the image signal based on the second fluorescent light Lw3 output from the third imaging element 522c. The "high-resolution color image" mentioned here is a color image acquired by a high-resolution imaging element, and the "high-sensitivity monochrome image" is a monochrome image acquired by a high-sensitivity imaging element.

[0492] Figure 22 An example of a timing chart showing the light source emission and the imaging element exposure in the third mode of the seventh embodiment.

[0493] Figure 22 (a) shows the exposure state of the first imaging element 522a, (c) shows the exposure state of the second imaging element 522b, and (e) shows the exposure state of the third imaging element 522c. In Figure 22In (a), (c), (e) of FIG. 21, the vertical axis indicates the horizontal lines of the first imaging element 522a, the second imaging element 522b, the third imaging element 522c, and the horizontal axis indicates time. The line R1 indicates the pixel data read start timing of each horizontal line of each image frame. The "wideband light image frame" between the lines R1 is an image frame for receiving (exposure) of the wideband reflected light Lw1 from the observation target S. The "first fluorescent light image frame" between the lines R1 is an image frame for receiving (exposure) of the first fluorescent light Lw2 from the observation target S. The "second fluorescent light image frame" between the lines R1 is an image frame for receiving (exposure) of the second fluorescent light Lw3 from the observation target S. Figure 22 (b) of FIG. 21 shows the light emission timing of the wideband light in the wideband light source 11, (d) shows the light emission timing of the first narrowband light in the first narrowband light source 12, and (f) shows the light emission timing of the second narrowband light in the second narrowband light source 13.

[0494] In this mode, as described above, the light emission in the light source device 10 and the irradiation of the wideband light and the first narrowband light to the observation target S are performed in a time-division manner. On the other hand, the light emission in the light source device 10 and the irradiation of the second narrowband light to the observation target S are performed continuously.

[0495] Therefore, the exposure (light reception) in the first imaging element 522a and the second imaging element 522b with respect to the wideband reflected light Lw1 and the first fluorescent light Lw2 from the observation target S is performed in a time-division manner. On the other hand, the exposure (light reception) in the third imaging element 522c with respect to the second fluorescent light Lw3 from the observation target S is performed continuously. Therefore, the control device 90 (control section 94) performs control so that the time-division light emission timing of the wideband light and the first narrowband light from the light source device 10 and the timing of reading the image data from the first imaging element 522a and the second imaging element 522b are associated with each other.

[0496] Specifically, based on the common synchronization signal, the time-division light emission of the wideband light and the first narrowband light in the wideband light source 11 and the first narrowband light source 12 is performed, and the exposure and the image data reading in the first imaging element 522a and the second imaging element 522b are performed. More specifically, the wideband light and the first narrowband light are alternately emitted in time, respectively, so that the first imaging element 522a and the second imaging element 522b are not simultaneously exposed to both the wideband reflected light Lw1 and the first fluorescent light Lw2.

[0497] Then, the image data is read so that the image signal of the wideband light image frame exposed by the wideband reflected light Lwl and the image signal of the first fluorescent light image frame exposed by the first fluorescent light Lw2 are output from the first imaging element 522a and the second imaging element 522b. Thereby, the first imaging element 522a and the second imaging element 522b respectively alternately repeat the output of the image signal of the wideband light image frame and the image signal of the first fluorescent light image frame.

[0498] On the other hand, when the second narrowband light is emitted by the light source device 10, the reading of the image data from the third imaging element 522c can be performed at any time. As a result, the third imaging element 522c continuously repeats the output of the image signal of the second fluorescent light image frame.

[0499] Then, the image generation section 93 (image processing section 931) generates a normal light capture image of the observation target S, which is a reflected image of the wideband light (white light), from the image signal of the wideband light image frame output from the first imaging element 522a. Further, the image generation section 93 (image processing section 931) generates a first fluorescent light capture image, which is a capture image based on the first fluorescent light Lw2 of the observation target S, from the image signal of the first fluorescent light image frame output from the second imaging element 522b. Further, the image generation section 93 (image processing section 931) generates a second fluorescent light capture image, which is a capture image based on the second fluorescent light Lw3 of the observation target S, from the image signal of the second fluorescent light image frame from the third imaging element 522c.

[0500] As described above, in this mode, within a common time frame, the normal light capture image which is a reflected image of the visible light (white light), the first fluorescent light capture image which is an image in which the first substance in the observation target S is emphasized (i.e., the first substance in the observation target S emits fluorescent light from being excited by the narrowband light), and the second fluorescent light capture image which is an image in which the second substance in the observation target S is emphasized (i.e., the second substance in the observation target S emits fluorescent light from being excited by the narrowband light) are acquired. Therefore, the user can compare and observe the normal light capture image, the first fluorescent light capture image, and the second fluorescent light capture image of the observation target S or observe a combined image (superimposed image) formed by these images via the display device 70.

[0501] Note that, in the above description, the case where the first narrowband light and the second narrowband light are emitted by the light source device 10 has been described. However, the present application is not limited to this. For example, the first narrowband light and the second narrowband light can be emitted by the light source device 10 in a time-division manner. Figure 22In the example shown, the emission of broadband light and first narrowband light is started and terminated when no image data is read from the first imaging element 522a and the second imaging element 522b. Therefore, in the broadband light image frames of the first imaging element 522a and the second imaging element 522b, the first fluorescence Lw2 from the observed target S illuminated by the first narrowband light can be suppressed from incident on the first imaging element 522a. Furthermore, in the first fluorescence image frames of the first imaging element 522a and the second imaging element 522b, the broadband reflected light Lwl from the observed target S illuminated by broadband light can be suppressed from incident on the first imaging element 522a and the second imaging element 522b.

[0502] It should be noted that the start and end timings of the light emission of broadband light and the first narrowband light are not limited to... Figure 22 The example shown can be configured for arbitrary timing. For example, when reading image data from the first imaging element 522a and the second imaging element 522b (see [example missing]). Figure 22 The "R1" in the text can start or stop the emission of one or both of the broadband light and the first narrowband light. For example, when the intensity of the fluorescence, which is the light receiving target in the first fluorescence image frame, is weak (i.e., when the fluorescence emission amount is small), the first narrowband light can be emitted from the first narrowband light source 12 while reading the image data of the broadband light image frame. In this case, the exposure time of the fluorescence of the first fluorescence image frame can be extended, which is beneficial to obtaining image data of a bright first fluorescence image frame. Specifically, when the first fluorescence Lw2 has a light amount that is sufficiently smaller than that of the broadband reflected light Lw1 and the effect of the first fluorescence Lw2 on the broadband light image frame is sufficiently smaller than the effect of the broadband reflected light Lw1 on the broadband light image frame, the first narrowband light source 12 can continuously emit the first narrowband light.

[0503] In addition, in this mode, the image signal of the first fluorescence image frame is also output from the first imaging element 522a, and the image signal of the broadband light image frame is also output from the second imaging element 522b. However, in the above example, these image frames are not used to generate the captured image. In the above example, the image data of these image frames not used to generate the captured image are also repeatedly output as image signals from the imaging elements (first imaging element 522a and second imaging element 522b), but the image data of the image frames not used to generate the captured image may not be output as image signals from the imaging elements.

[0504] Alternatively, in the above example, the captured image can also be generated using these image frames that were not used to generate the captured image (i.e., the first fluorescence image frame from the first imaging element 522a and the broadband light image frame from the second imaging element 522b).

[0505] That is, a captured image based on the first fluorescent light Lw2 can be generated based on the image signal of the first fluorescent light image frame from the first imaging element 522a. For example, a captured image based on the first fluorescent light Lw2 can be generated based on the image signal of the first fluorescent light image frame from both the first imaging element 522a and the second imaging element 522b.

[0506] In addition, a captured image based on the wideband reflected light Lw1 can be generated based on the image signal of the wideband light image frame from the second imaging element 522b. That is, a captured image based on the wideband reflected light Lw1 can be generated based on the image signal of the wideband light image frame from both the first imaging element 522a and the second imaging element 522b.

[0507] The captured images generated in this way can or can not be used to generate an output image.

[0508] The captured images that are not used to generate an output image can be used for any purpose (for example, correction processing regarding the brightness of the output image or adjustment processing regarding the focus position).

[0509] [The eighth embodiment]

[0510] In the present embodiment, the same reference numerals are affixed to the same or corresponding parts as those of the first to seventh embodiments described above, and detailed description thereof is omitted.

[0511] Figure 23 is a diagram for explaining the types of light incident to the imaging elements (the first imaging element 522a, the second imaging element 522b, the third imaging element 522c) according to the eighth embodiment.

[0512] The camera head 50 (specifically, the imaging section 52) of the present embodiment includes a three-plate type imaging module (see Figure 5 and Figure 6 ), and includes the first imaging element 522a having the color filter CF, and the second imaging element 522b and the third imaging element 522c not having the color filter CF.

[0513] The color filter CF provided in the first imaging element 522a of the present embodiment transmits the wide-band reflected light Lwl and the first fluorescent light Lw2 (as described later) received by the first imaging element 522a, but can or can not transmit light in a wavelength band other than the wide-band reflected light Lwl and the first fluorescent light Lw2 (for example, the second fluorescent light Lw3 and the third fluorescent light Lw4). Note that the second imaging element 522b and the third imaging element 522c of the present example do not include the color filter CF, but the second imaging element 522b can include a color filter CF capable of transmitting the wide-band reflected light Lwl and the first fluorescent light Lw2, and the third imaging element 522c can include a color filter CF capable of transmitting the second fluorescent light Lw3 and the third fluorescent light Lw4.

[0514] The first imaging element 522a has relatively lower sensitivity and higher resolution (for example, 4K resolution) than the second imaging element 522b and the third imaging element 522c, and the second imaging element 522b and the third imaging element 522c have relatively higher sensitivity and lower resolution (for example, HD resolution) than the first imaging element 522a. The second imaging element 522b and the third imaging element 522c can have the same or different characteristics from each other. As described above, the resolution of the first imaging element 522a is higher than the resolution of the second imaging element 522b and the third imaging element 522c, but the sensitivity of the second imaging element 522b and the third imaging element 522c is higher than the sensitivity of the first imaging element 522a.

[0515] However, the resolution and sensitivity of the first imaging element 522a to the third imaging element 522c are not limited thereto, and the relationship between the resolution and sensitivity of the first imaging element 522a to the third imaging element 522c is not limited thereto.

[0516] The light source device 10 (see Figure 1B ) emits light from at least one of the wide-band light source 11, the first narrow-band light source 12, the second narrow-band light source 13, and the third narrow-band light source 14, and is capable of irradiating the observation target S with at least one of the wide-band light, the first narrow-band light, the second narrow-band light, and the third narrow-band light. Therefore, the observation light Lf from the observation target S can include the wide-band reflected light Lwl which is reflected light as the wide-band light, the first fluorescent light Lw2 emitted from the first substance excited by the first narrow-band light, the second fluorescent light Lw3 emitted from the second substance excited by the second narrow-band light, and the third fluorescent light Lw4 emitted from the third substance excited by the third narrow-band light. Note that the wide-band reflected light Lwl and the first fluorescent light Lw2 are light included in the first wavelength band, and the second fluorescent light Lw3 and the third fluorescent light Lw4 are light included in the second wavelength band other than the first wavelength band.

[0517] The observation light Lf incident on the optical element 15 is split by the optical element 15 into a first light flux Lf1, a second light flux Lf2, and a third light flux Lf3. The optical element 15 of the present embodiment guides a portion of light included in the first wavelength band as the first light flux Lf1 to the first imaging element 522a, guides a portion of light included in the first wavelength band as the second light flux Lf2 to the second imaging element 522b, and guides light included in the second wavelength band as the third light flux Lf3 to the third imaging element 522c.

[0518] As described above, in the present embodiment, the first light flux Lf1 in which the light within the first wavelength band in the observation light Lf is partially suppressed and the light within the wavelength bands of the second fluorescent light Lw3 and the third fluorescent light Lw4 is partially, substantially, or completely suppressed is guided to the first imaging element 522a by the optical element 15. That is, light including at least a portion of the broadband reflected light Lw1 is guided to the first imaging element 522a as the first light flux Lf1. Further, the second light flux Lf2 in which the light within the first wavelength band in the observation light Lf is partially suppressed and the light within the wavelength bands of the second fluorescent light Lw3 and the third fluorescent light Lw4 is partially, substantially, or completely suppressed is guided to the second imaging element 522b. That is, light including at least a portion of the broadband reflected light Lw1 and the first fluorescent light Lw2 is guided to the second imaging element 522b as the second light flux Lf2. Further, the third light flux Lf3 in which the light within the first wavelength band in the observation light Lf is partially, substantially, or completely suppressed is guided to the third light flux Lf3. That is, light including at least the second fluorescent light Lw3 and the third fluorescent light Lw4 is guided to the third imaging element 522c as the third light flux Lf3.

[0519] The medical observation system 100 of the present embodiment having the above-described structure can acquire various captured images of the observation target S according to the following observation modes (first to fifth modes).

[0520] <First to third modes>

[0521] The first to third modes of the present embodiment are similarly performed to the first to third modes of the seventh embodiment described above.

[0522] Thus, in the first mode, the broadband light and the first narrowband light are emitted by the light source device 10 in a time-division manner, and the broadband reflected light Lwl and the first fluorescent light Lw2 are received by the first imaging element 522a and the second imaging element 522b in a time-division manner. Further, in the second mode, the broadband light and the second narrowband light are continuously emitted by the light source device 10, the broadband reflected light Lwl is continuously received by the first imaging element 522a and the second imaging element 522b, and the second fluorescent light Lw3 is continuously received by the third imaging element 522c. Further, in the third mode, the broadband light and the first narrowband light are emitted by the light source device 10 in a time-division manner and the second narrowband light is continuously emitted, and the broadband reflected light Lwl and the first fluorescent light Lw2 are received by the first imaging element 522a and the second imaging element 522b in a time-division manner and the second fluorescent light Lw3 is continuously received by the third imaging element 522c.

[0523] In the first mode to the third mode of the present embodiment, the third narrowband light source 14 is placed in an off state, and the third narrowband light is not emitted from the light source device 10.

[0524] <Fourth Mode>

[0525] The fourth mode of the present embodiment is an observation mode in which the broadband light and the third narrowband light are irradiated to the observation target S and a captured image based on the broadband reflected light Lwl and the third fluorescent light Lw4 from the observation target S is acquired.

[0526] That is, the control device 90 (control section 94) controls the light source device 10 (the broadband light source 11 and the third narrowband light source 14), and the broadband light and the third narrowband light are continuously emitted from the light source device 10, and the broadband light and the third narrowband light are continuously emitted to the observation target S. Note that, in this mode, the first narrowband light source 12 and the second narrowband light source 13 are placed in an off state, and the first narrowband light and the second narrowband light are not emitted from the light source device 10.

[0527] Then, the optical element 15 continuously guides the first light flux Lfl including the broadband reflected light Lwl from the observation target S irradiated with the broadband light to the first imaging element 522a. Further, the optical element 15 continuously guides the second light flux Lf2 including the broadband reflected light Lwl from the observation target S irradiated with the broadband light to the second imaging element 522b. Further, the optical element 15 continuously guides the third light flux Lf3 including the third fluorescent light Lw4 from the observation target S with the third narrowband light to the third imaging element 522c.

[0528] As a result, the first imaging element 522a continuously receives the first light flux Lf1 including the wideband reflected light Lw1 under the control of the control device 90 (control section 94), and continuously and repeatedly outputs an image signal based on the wideband reflected light Lw1. Further, the second imaging element 522b continuously receives the second light flux Lf2 including the wideband reflected light Lw1 under the control of the control device 90 (control section 94), and continuously and repeatedly outputs an image signal based on the wideband reflected light Lw1. Further, the third imaging element 522c continuously receives the third light flux Lf3 including the third fluorescent light Lw4 under the control of the control device 90 (control section 94), and continuously and repeatedly outputs an image signal based on the third fluorescent light Lw4.

[0529] Then, under the control of the control section 94, the image generation section 93 (image processing section 931) generates a captured image (high-resolution color image) of the observation target S based on the wideband reflected light Lw1 from the image signal based on the wideband reflected light Lw1 output from the first imaging element 522a. Further, under the control of the control section 94, the image generation section 93 (image processing section 931) generates a captured image (high-sensitivity monochrome image) of the observation target S based on the third fluorescent light Lw4 from the image signal based on the third fluorescent light Lw4 output from the third imaging element 522c. The "high-resolution color image" mentioned here is a color image acquired by a high-resolution imaging element, and the "high-sensitivity monochrome image" is a monochrome image acquired by a high-sensitivity imaging element.

[0530] As described above, in this mode, a normal light captured image that is a reflected image of visible light (white light) and a third fluorescent light captured image in which a third substance in the observation target S, that is, a third substance in the observation target S excited by narrowband light emits fluorescent light, are acquired within a common time frame. Therefore, the user can compare and observe the normal light captured image and the third fluorescent light captured image of the observation target S and observe a combined image (superimposed image) formed by these images via the display device 70.

[0531] Note that, in this mode, the image signal of the wideband light image frame is also output from the second imaging element 522b, but in the above-described example, the wideband light image frame from the second imaging element 522b is not used to generate a captured image. In the above-described example, the image data of the wideband light image frame that is not used to generate a captured image is repeatedly output as an image signal from the second imaging element 522b, but the image data of the wideband light image frame that is not used to generate a captured image can not be output as an image signal from the second imaging element 522b.

[0532] Further, in the above example, the captured image based on the wideband reflected light Lwl can be generated based on the image signal from the wideband light image frame of the second imaging element 522b that is not used to generate the captured image. That is, the captured image based on the wideband reflected light Lwl can be generated based on the image signal from both the wideband light image frame of the first imaging element 522a and the wideband light image frame of the second imaging element 522b.

[0533] The captured image generated in this way can or can not be used to generate an output image.

[0534] The captured image that is not used to generate the output image can be used for any purpose (e.g., correction processing regarding the brightness of the output image or adjustment processing regarding the focus position).

[0535] <Fifth Mode>

[0536] The fifth mode of the present embodiment is an observation mode in which the wideband light and the first to third narrowband lights are irradiated to the observation target S to acquire captured images based on the wideband reflected light Lwl and the first to third fluorescent lights Lw2 to Lw4 from the observation target S.

[0537] That is, the control device 90 (control section 94) controls the light source device 10 (wideband light source 11 and first to third narrowband light sources 12 to 14), and the wideband light and the first narrowband light are emitted from the light source device 10 in a time-division manner, and the second narrowband light and the third narrowband light are emitted in a time-division manner. As a result, the wideband light and the first narrowband light are emitted to the observation target S in a time-division manner, and the second narrowband light and the third narrowband light are emitted to the observation target S in a time-division manner. Note that each of the wideband light and the first narrowband light can also be emitted simultaneously with one of the second narrowband light and the third narrowband light, and emitted to the observation target S simultaneously.

[0538] Then, the optical element 15 sequentially guides the first light flux Lfl including the wideband reflected light Lwl from the observation target S irradiated with the wideband light and the first light flux Lfl including the first fluorescent light Lw2 from the observation target S irradiated with the first narrowband light to the first imaging element 522a. Further, the optical element 15 sequentially guides the second light flux Lf2 including the wideband reflected light Lwl from the observation target S irradiated with the wideband light and the second light flux Lf2 including the first fluorescent light Lw2 from the observation target S irradiated with the first narrowband light to the second imaging element 522b. Further, the optical element 15 sequentially guides the third light flux Lf3 including the second fluorescent light Lw3 from the observation target S irradiated with the second narrowband light and the third light flux Lf3 including the third fluorescent light Lw4 from the observation target S irradiated with the third narrowband light to the third imaging element 522c.

[0539] As a result, the first imaging element 522a sequentially receives the first light flux Lf1 including the wideband reflected light Lwl and the first light flux Lf1 including the first fluorescent light Lw2. Then, the first imaging element 522a sequentially and repeatedly outputs an image signal based on the wideband reflected light Lwl and an image signal based on the first fluorescent light Lw2 under the control of the control device 90 (control section 94).

[0540] Further, the second imaging element 522b sequentially receives the second light flux Lf2 including the wideband reflected light Lwl and the second light flux Lf2 including the first fluorescent light Lw2. Then, the second imaging element 522b sequentially and repeatedly outputs an image signal based on the wideband reflected light Lwl and an image signal based on the first fluorescent light Lw2 under the control of the control device 90 (control section 94).

[0541] Further, the third imaging element 522c sequentially receives the third light flux Lf3 including the second fluorescent light Lw3 and the third light flux Lf3 including the third fluorescent light Lw4. Then, the third imaging element 522c sequentially and repeatedly outputs an image signal based on the second fluorescent light Lw3 and an image signal based on the third fluorescent light Lw4 under the control of the control device 90 (control section 94).

[0542] Then, under the control of the control section 94, the image generation section 93 (image processing section 931) generates a captured image (high-resolution color image) of the observation target S based on the wideband reflected light Lwl from the image signal based on the wideband reflected light Lwl output from the first imaging element 522a. Further, under the control of the control section 94, the image generation section 93 (image processing section 931) generates a captured image (high-sensitivity monochrome image) of the observation target S based on the first fluorescent light Lw2 from the image signal based on the first fluorescent light Lw2 output from the second imaging element 522b. The "high-resolution color image" mentioned here is a color image acquired by a high-resolution imaging element, and the "high-sensitivity monochrome image" is a monochrome image acquired by a high-sensitivity imaging element.

[0543] Further, under the control of the control section 94, the image generation section 93 (image processing section 931) generates a captured image (high-sensitivity monochrome image) of the observation target S based on the second fluorescent light Lw3 from the image signal based on the second fluorescent light Lw3 output from the third imaging element 522c. Further, under the control of the control section 94, the image generation section 93 (image processing section 931) generates a captured image (high-sensitivity monochrome image) of the observation target S based on the third fluorescent light Lw4 from the image signal based on the third fluorescent light Lw4 output from the third imaging element 522c. The "high-sensitivity monochrome image" mentioned here is a monochrome image acquired by a high-sensitivity imaging element.

[0544] As described above, in this mode, within a common time frame, a normal light-captured image that is a reflected image of visible light (white light) and a first to third fluorescent-captured image in which a first to third substance within the observation target S is emphasized, that is, fluorescence emitted from the first to third substance within the observation target S excited by narrow-band light are acquired. Therefore, the user can compare and observe the normal light-captured image, the first to third fluorescent-captured image of the observation target S or observe a combined image (superimposed image) formed by these images via the display device 70.

[0545] Note that, in this mode, the image signal of the first fluorescent image frame is also output from the first imaging element 522a, and the image signal of the wide-band light image frame is also output from the second imaging element 522b. However, in the above example, these image frames are not used for generating the captured image. In the above example, the image data of these image frames that are not used for generating the captured image are also repeatedly output as image signals from the imaging elements (the first imaging element 522a and the second imaging element 522b), but the image data of the image frames that are not used for generating the captured image can not be output as image signals from the imaging elements.

[0546] In addition, in the above example, these image frames that are not used for generating the captured image (that is, the first fluorescent image frame from the first imaging element 522a and the wide-band light image frame from the second imaging element 522b) can also be used for generating the captured image.

[0547] That is, the captured image based on the first fluorescent light Lw2 can be generated based on the image signal of the first fluorescent image frame from the first imaging element 522a. For example, the captured image based on the first fluorescent light Lw2 can be generated based on the image signal of the first fluorescent image frame from both the first imaging element 522a and the second imaging element 522b.

[0548] Further, the captured image based on the wide-band reflected light Lw1 can be generated based on the image signal of the wide-band light image frame from the second imaging element 522b. That is, the captured image based on the wide-band reflected light Lw1 can be generated based on the image signal of the wide-band light image frame from both the first imaging element 522a and the second imaging element 522b.

[0549] The captured image generated in this way can or can not be used for generating the output image.

[0550] The captured image that is not used for generating the output image can be used for any purpose (for example, correction processing regarding the brightness of the output image or processing regarding adjustment of the focus position).

[0551] [Ninth Embodiment]

[0552] In the present embodiment, the same reference numerals are given to portions common to the first to eighth embodiments described above, and detailed description is omitted.

[0553] Figure 24 is a diagram for explaining the type of light incident on the imaging elements (first imaging element 522a, second imaging element 522b, third imaging element 522c) according to the ninth embodiment.

[0554] The camera head 50 (specifically, the imaging section 52) of the present embodiment includes a three-plate type imaging module (see Figure 5 and Figure 6 ), and includes the first imaging element 522a having the color filter CF, and the second imaging element 522b and the third imaging element 522c not having the color filter CF.

[0555] The color filter CF provided in the first imaging element 522a of the present embodiment transmits the wideband reflected light Lw1 and the first fluorescent light Lw2 (as described later) received by the first imaging element 522a, but can or can not transmit light in a wavelength band different from the wideband reflected light Lw1 and the first fluorescent light Lw2 (for example, the second fluorescent light Lw3 and the third fluorescent light Lw4). Note that the second imaging element 522b and the third imaging element 522c of the present example do not include the color filter CF, but the second imaging element 522b and the third imaging element 522c can each include a color filter CF that can transmit the second fluorescent light Lw3 and the third fluorescent light Lw4.

[0556] The first imaging element 522a has relatively lower sensitivity and higher resolution (for example, 4K resolution) than the second imaging element 522b and the third imaging element 522c, and the second imaging element 522b and the third imaging element 522c have relatively higher sensitivity and lower resolution (for example, HD resolution) than the first imaging element 522a. The second imaging element 522b and the third imaging element 522c can have the same or different characteristics from each other. However, the resolution and sensitivity of the first imaging element 522a to the third imaging element 522c are not limited thereto, and the relationship between the resolution and sensitivity of the first imaging element 522a to the third imaging element 522c is not limited thereto.

[0557] The light source device 10 (see Figure 1B) emits light from at least one of the broadband light source 11, the first narrow-band light source 12, the second narrow-band light source 13, and the third narrow-band light source 14, and is capable of irradiating the observation target S with at least one of the broadband light, the first narrow-band light, the second narrow-band light, and the third narrow-band light. Therefore, the observation light Lf from the observation target S can include the broadband reflected light Lwl that is the reflected light of the broadband light, the first fluorescent light Lw2 emitted from the first substance excited by the first narrow-band light, the second fluorescent light Lw3 emitted from the second substance excited by the second narrow-band light, and the third fluorescent light Lw4 emitted from the third substance excited by the third narrow-band light. Note that the broadband reflected light Lwl and the first fluorescent light Lw2 are light included in the first wavelength band, and the second fluorescent light Lw3 and the third fluorescent light Lw4 are light included in a second wavelength band outside the first wavelength band.

[0558] The observation light Lf incident on the optical element 15 is split by the optical element 15 into the first light flux Lf1, the second light flux Lf2, and the third light flux Lf3. The optical element 15 of the present embodiment guides light included in the first wavelength band as the first light flux Lf1 to the first imaging element 522a, guides light including the second fluorescent light Lw3 as the second light flux Lf2 to the second imaging element 522b, and guides light including the third fluorescent light Lw4 as the third light flux Lf3 to the third imaging element 522c.

[0559] As described above, in the present embodiment, the first light flux Lf1 in which light in the wavelength band of the second fluorescent light Lw3 and the third fluorescent light Lw4 in the observation light Lf is partially, substantially, or completely suppressed is guided to the first imaging element 522a. That is, light including the broadband reflected light Lwl and the first fluorescent light Lw2 is guided to the first imaging element 522a as the first light flux Lf1. Further, in the observation light Lf, the second light flux Lf2 in which light of the first wavelength band is partially, substantially, or completely suppressed and light of the wavelength band of the third fluorescent light Lw4 is partially, substantially, or completely suppressed is guided to the second imaging element 522b. That is, light including at least the second fluorescent light Lw3 is guided to the second imaging element 522b as the second light flux Lf2. Further, in the observation light Lf, the third light flux Lf3 in which light in the first wavelength band is partially, substantially, or completely suppressed and light in the wavelength band of the second fluorescent light Lw3 is partially, substantially, or completely suppressed is guided to the third imaging element 522c. That is, light including at least the third fluorescent light Lw4 is guided to the third imaging element 522c as the third light flux Lf3.

[0560] The medical observation system 100 of the present embodiment having the above-described structure can acquire various captured images of the observation target S according to the following observation modes (first to sixth modes).

[0561] <First Mode> In the first mode, the first narrow-band light source 12 is turned on, and the second and third narrow-band light sources 13 and 14 are turned off. In this case, the first narrow-band light source 12 emits the first narrow-band light, and the observation target S is irradiated with the first narrow-band light.

[0562] The first mode of the present embodiment is an observation mode in which the wideband light and the first narrowband light are irradiated to the observation target S to acquire a captured image of the observation target S based on the wideband reflected light Lwl and the first fluorescent light Lw2 from the observation target S.

[0563] That is, the control device 90 (the control section 94 (see Figure 7 )) controls the light source device 10 (the wideband light source 11 and the first narrowband light source 12 (see Figure 1A )), emits the wideband light and the first narrowband light from the light source device 10 in a time-division manner, and emits the wideband light and the first narrowband light to the observation target S in a time-division manner. Note that, in this mode, the second narrowband light source 13 and the third narrowband light source 14 are placed in an off state, and the second narrowband light and the third narrowband light are not emitted from the light source device 10.

[0564] Then, the optical element 15 sequentially guides the first light flux Lfl including the wideband reflected light Lwl from the observation target S irradiated with the wideband light and the first light flux Lfl including the first fluorescent light Lw2 from the observation target S irradiated with the first narrowband light to the first imaging element 522a. Thus, the first imaging element 522a sequentially receives the first light flux Lfl including the wideband reflected light Lwl and the first light flux Lfl including the first fluorescent light Lw2.

[0565] Then, the first imaging element 522a outputs an image signal based on the wideband reflected light Lwl and an image signal based on the first fluorescent light Lw2 sequentially and repeatedly under the control of the control device 90 (the control section 94 (see Figure 7 ).

[0566] Then, under the control of the control section 94, the image generation section 93 (specifically, the image processing section 931 (see Figure 7 )) generates a captured image (a high-resolution color image) of the observation target S based on the wideband reflected light Lwl from the image signal based on the wideband reflected light Lwl output from the first imaging element 522a. Further, under the control of the control section 94, the image generation section 93 (the image processing section 931) generates a captured image (a high-resolution color image) of the observation target S based on the first fluorescent light Lw2 from the image signal based on the first fluorescent light Lw2 output from the first imaging element 522a. The “high-resolution color image” mentioned here is a color image acquired by a high-resolution imaging element.

[0567] As described above, in this mode, the normal light-captured image that is a reflection image of visible light (white light) and the first fluorescent light-captured image in which the first substance in the observation target S is emphasized, that is, the first fluorescent light emitted from the first substance in the observation target S excited by the narrow-band light are acquired in a common time frame. Therefore, the user can compare and observe the normal light-captured image and the first fluorescent light-captured image of the observation target S and observe a combined image (superimposed image) formed by these images via the display device 70 (see FIG. 6). Figure 1A ).

[0568] <Second Mode>

[0569] The second mode of the present embodiment is an observation mode in which the wide-band light and the second narrow-band light are irradiated to the observation target S to acquire captured images based on the wide-band reflected light Lwl and the second fluorescent light Lw3 from the observation target S.

[0570] That is, the control device 90 (control section 94) controls the light source device 10 (the wide-band light source 11 and the second narrow-band light source 13) to continuously emit the wide-band light and the second narrow-band light from the light source device 10 to continuously irradiate the wide-band light and the second narrow-band light to the observation target S. Note that, in this mode, the first narrow-band light source 12 and the third narrow-band light source 14 are placed in an off state, and the first narrow-band light and the third narrow-band light are not emitted from the light source device 10.

[0571] Then, the optical element 15 continuously guides the first light flux Lfl including the wide-band reflected light Lwl from the observation target S irradiated with the wide-band light to the first imaging element 522a. Further, the optical element 15 continuously guides the second light flux Lf2 including the second fluorescent light Lw3 from the observation target S irradiated with the second narrow-band light to the second imaging element 522b. In addition, the optical element 15 continuously guides the third light flux Lf3 including the second fluorescent light Lw3 from the observation target S irradiated with the second narrow-band light to the third imaging element 522c.

[0572] As a result, the first imaging element 522a continuously receives the first light flux Lfl including the wide-band reflected light Lwl. Further, the second imaging element 522b continuously receives the second light flux Lf2 including the second fluorescent light Lw3, and the third imaging element 522c continuously receives the third light flux Lf3 including the second fluorescent light Lw3.

[0573] Then, under the control of the control device 90 (control section 94), the first imaging element 522a continuously and repeatedly outputs the image signal based on the wide-band reflected light Lwl, and the second imaging element 522b and the third imaging element 522c continuously and repeatedly output the image signal based on the second fluorescent light Lw3.

[0574] Then, under the control of the control section 94, the image generation section 93 (image processing section 931) generates a captured image (high-resolution color image) of the observation target S based on the wide-band reflected light Lwl from the image signal based on the wide-band reflected light Lwl output from the first imaging element 522a. Further, under the control of the control section 94, the image generation section 93 (image processing section 931) generates a captured image (high-sensitivity monochrome image) of the observation target S based on the second fluorescent light Lw3 from the image signal based on the second fluorescent light Lw3 output from the second imaging element 522b. The "high-resolution color image" mentioned here is a color image acquired by a high-resolution imaging element, and the "high-sensitivity monochrome image" is a monochrome image acquired by a high-sensitivity imaging element.

[0575] As described above, in this mode, within a common time frame, a normal light captured image that is a reflected image of visible light (white light) and a second fluorescent light captured image in which the second substance of the observation target S is emphasized, that is, the second fluorescent light emitted from the second substance of the observation target S excited by narrow-band light are acquired. Therefore, the user can compare and observe the normal light captured image and the second fluorescent light captured image of the observation target S and observe a combined image (superimposed image) formed by these images via the display device 70.

[0576] Note that, in the example described above, the wide-band light and the second narrow-band light are continuously emitted from the light source device 10, but the light source device 10 can also be controlled by the control device 90 (control section 94) to turn off the emission of each of the wide-band light and the second narrow-band light midway. However, by continuously emitting the wide-band light and the second narrow-band light by the light source device 10, it is possible to acquire bright captured images, it is possible to suppress an increase in noise caused by gain adjustment, and it is possible to prevent a significant reduction in frame rate.

[0577] Note that, in this mode, the image signal of the second fluorescent light image frame is also output from the third imaging element 522c, but in the example described above, the second fluorescent light image frame from the third imaging element 522c is not used to generate a captured image. Also, in the example described above, the image data of the second fluorescent light image frame that is not used to generate a captured image is repeatedly output as an image signal from the third imaging element 522c, but the image data of the second fluorescent light image frame that is not used to generate a captured image can also not be output as an image signal from the third imaging element 522c.

[0578] Further, in the example described above, it is possible to generate a captured image based on the second fluorescent light Lw3 based on the image signal of the second fluorescent light image frame that is not used to generate a captured image from the third imaging element 522c. For example, it is possible to generate a captured image based on the second fluorescent light Lw3 based on the image signal of the second fluorescent light image frame from the second imaging element 522b and the third imaging element 522c.

[0579] The captured image generated in this way can or can not be used to generate an output image.

[0580] The captured image that is not used to generate an output image can be used for any purpose (e.g., correction processing regarding luminance of the output image or adjustment processing regarding a focus position).

[0581] <Third Mode>

[0582] The third mode of the present embodiment is an observation mode in which the wideband light, the first narrowband light, and the second narrowband light are irradiated to the observation target S to acquire a captured image based on the wideband reflected light Lwl, the first fluorescent light Lw2, and the second fluorescent light Lw3 from the observation target S.

[0583] That is, the control device 90 (the control section 94) controls the light source device 10 (the wideband light source 11, the first narrowband light source 12, and the second narrowband light source 13) to emit the wideband light and the first narrowband light in a time-division manner from the light source device 10, and to continuously emit the second narrowband light. As a result, the wideband light and the first narrowband light are emitted to the observation target S in a time-division manner, and the second narrowband light is continuously emitted to the observation target S. Note that, in this mode, the third narrowband light source 14 is placed in an off state, and the third narrowband light is not emitted from the light source device 10.

[0584] Then, the optical element 15 sequentially guides the first light flux Lfl including the wideband reflected light Lwl from the observation target S irradiated with the wideband light and the first light flux Lfl including the first fluorescent light Lw2 from the observation target S irradiated with the first narrowband light to the first imaging element 522a. Further, the optical element 15 continuously guides the second light flux Lf2 including the second fluorescent light Lw3 from the observation target S irradiated with the second narrowband light to the second imaging element 522b. Further, the optical element 15 continuously guides the third light flux Lf3 including the second fluorescent light Lw3 from the observation target S irradiated with the second narrowband light to the third imaging element 522c.

[0585] As a result, the first imaging element 522a sequentially receives the first light flux Lfl including the wideband reflected light Lwl and the first light flux Lfl including the first fluorescent light Lw2. Further, the second imaging element 522b continuously receives the second light flux Lf2 including the second fluorescent light Lw3. Further, the third imaging element 522c continuously receives the third light flux Lf3 including the second fluorescent light Lw3.

[0586] Then, the first imaging element 522a sequentially and repeatedly outputs the image signal based on the wideband reflected light Lwl and the image signal based on the first fluorescent light Lw2 under the control of the control device 90 (control section 94). Further, the second imaging element 522b and the third imaging element 522c each continuously and repeatedly output the image signal based on the second fluorescent light Lw3 under the control of the control device 90 (control section 94).

[0587] Then, under the control of the control section 94, the image generation section 93 (image processing section 931) generates a captured image (high-resolution color image) of the observation target S based on the wideband reflected light Lwl from the image signal based on the wideband reflected light Lwl output from the first imaging element 522a. Further, under the control of the control section 94, the image generation section 93 (image processing section 931) generates a captured image (high-resolution color image) of the observation target S based on the first fluorescent light Lw2 from the image signal based on the first fluorescent light Lw2 output from the first imaging element 522a. Further, under the control of the control section 94, the image generation section 93 (image processing section 931) generates a captured image (high-sensitivity monochrome image) of the observation target S based on the second fluorescent light Lw3 from the image signal based on the second fluorescent light Lw3 output from the second imaging element 522b. The “high-resolution color image” mentioned here is a color image acquired by a high-resolution imaging element, and the “high-sensitivity monochrome image” is a monochrome image acquired by a high-sensitivity imaging element.

[0588] As described above, in this mode, within a common time frame, a normal light captured image as a reflected image of visible light (white light), a first fluorescent light captured image as an image in which the first substance within the observation target S is emphasized (i.e., fluorescent light is emitted from the first substance within the observation target S excited by narrowband light), and a second fluorescent light captured image as an image in which the second substance within the observation target S is emphasized (i.e., fluorescent light is emitted from the second substance within the observation target S excited by narrowband light) are acquired. Therefore, the user can compare and observe the normal light captured image, the first fluorescent light captured image, and the second fluorescent light captured image of the observation target S or observe a combined image (superimposed image) formed by these images via the display device 70.

[0589] Note that, in this mode, the image signal of the second fluorescent light image frame is also output from the third imaging element 522c, but in the above-described example, the second fluorescent light image frame from the third imaging element 522c is not used for generating a captured image. In addition, in the above-described example, the image data of the second fluorescent light image frame not used for generating a captured image is repeatedly output as an image signal from the third imaging element 522c, but the image data of the second fluorescent light image frame not used for generating a captured image can also not be output as an image signal from the third imaging element 522c.

[0590] Further, in the above example, the captured image based on the second fluorescent light Lw3 can be generated based on the image signal of the second fluorescent image frame from the third imaging element 522c which is not used for generating the captured image. For example, the captured image based on the second fluorescent light Lw3 can be generated based on the image signal of the second fluorescent image frame from the second imaging element 522b and the third imaging element 522c.

[0591] The captured image generated in this way can or can not be used for generating the output image.

[0592] The captured image which is not used for generating the output image can be used for any purpose (for example, correction processing with respect to the brightness of the output image or adjustment processing with respect to the focus position).

[0593] <Fourth Mode>

[0594] The fourth mode of the present embodiment is an observation mode in which the wideband light and the third narrowband light are irradiated to the observation target S to acquire a captured image based on the wideband reflected light Lwl and the third fluorescent light Lw4 from the observation target S.

[0595] That is, the control device 90 (control section 94) controls the light source device 10 (wideband light source 11 and third narrowband light source 14), and the wideband light and the third narrowband light are continuously emitted from the light source device 10 to the observation target S. Note that, in this mode, the first narrowband light source 12 and the second narrowband light source 13 are placed in an off state, and the first narrowband light and the second narrowband light are not emitted from the light source device 10.

[0596] Then, the optical element 15 continuously guides the first light flux Lf1 including the wideband reflected light Lwl from the observation target S irradiated with the wideband light to the first imaging element 522a. Further, the optical element 15 continuously guides the second light flux Lf2 including the third fluorescent light Lw4 from the observation target S irradiated with the third narrowband light to the second imaging element 522b. Further, the optical element 15 continuously guides the third light flux Lf3 including the third fluorescent light Lw4 from the observation target S irradiated with the third narrowband light to the third imaging element 522c.

[0597] As a result, the first imaging element 522a continuously receives the first light flux Lf1 including the wideband reflected light Lw1 under the control of the control device 90 (control section 94), and continuously and repeatedly outputs an image signal based on the wideband reflected light Lw1. Further, the second imaging element 522b continuously receives the second light flux Lf2 including the third fluorescent light Lw4 under the control of the control device 90 (control section 94), and continuously and repeatedly outputs an image signal based on the third fluorescent light Lw4. Further, the third imaging element 522c continuously receives the third light flux Lf3 including the third fluorescent light Lw4 under the control of the control device 90 (control section 94), and continuously and repeatedly outputs an image signal based on the third fluorescent light Lw4.

[0598] Then, under the control of the control section 94, the image generation section 93 (image processing section 931) generates a captured image (high-resolution color image) of the observation target S based on the wideband reflected light Lw1 from the image signal based on the wideband reflected light Lw1 output from the first imaging element 522a. Further, under the control of the control section 94, the image generation section 93 (image processing section 931) generates a captured image (high-sensitivity monochrome image) of the observation target S based on the third fluorescent light Lw4 from the image signal based on the third fluorescent light Lw4 output from the third imaging element 522c. The "high-resolution color image" mentioned here is a color image acquired by a high-resolution imaging element, and the "high-sensitivity monochrome image" is a monochrome image acquired by a high-sensitivity imaging element.

[0599] As described above, in this mode, within a common time frame, a normal light captured image that is a reflected image of visible light (white light) and a third fluorescent light captured image in which the third substance in the observation target S is emphasized, that is, the third substance of the observation target S excited by narrowband light emits fluorescent light are acquired. Therefore, the user can compare ...

Claims

1. A medical observation system comprising: a light source device that emits broadband light of a first wavelength band, first narrowband light that excites a first substance to emit first fluorescent light of a wavelength band included in the first wavelength band, and second narrowband light that excites a second substance to emit second fluorescent light of a wavelength band not included in the first wavelength band; and a control section that controls the light source device, wherein the control section is configured to: control the light source device so that, in a first mode, the broadband light and the first narrowband light are emitted to an observation target in a time-division manner; and control the light source device so that, in a second mode different from the first mode, the broadband light and the second narrowband light are emitted to the observation target.

2. The medical observation system according to claim 1, further comprising: an imaging section including a first imaging element and a second imaging element; and an optical element that separates light from the observation target into a plurality of light fluxes including a first light flux and a second light flux, guides the first light flux to the first imaging element, and guides the second light flux to the second imaging element.

3. The medical observation system according to claim 2, wherein the second imaging element has higher sensitivity than the first imaging element.

4. The medical observation system according to claim 2, wherein the first imaging element includes a color filter.

5. The medical observation system according to claim 2, wherein the second imaging element does not have a color filter.

6. The medical observation system according to claim 2, wherein light within a wavelength band of the second fluorescent light is partially, substantially, or completely suppressed in the first light flux, and light within the first wavelength band is partially, substantially, or completely suppressed in the second light flux.

7. The medical observation system according to claim 6, wherein the optical element is configured to: in the first mode, sequentially guide the first light flux including reflected light from the observation target irradiated with the broadband light and the first light flux including the first fluorescent light from the observation target irradiated with the first narrowband light to the first imaging element; and in the second mode, guide the first light flux including reflected light from the observation target irradiated with the broadband light to the first imaging element, and guide the second light flux including the second fluorescent light from the observation target irradiated with the second narrowband light to the second imaging element.

8. The medical observation system according to claim 7, wherein in a third mode different from the first mode and the second mode, the control section controls the light source device so that the broadband light and the first narrowband light are emitted to the observation target in a time-division manner and the second narrowband light is emitted to the observation target, and ​ The optical element sequentially guides a first light flux including reflected light from the observation target irradiated with the wideband light and a first light flux including the first fluorescence from the observation target irradiated with the first narrowband light to the first imaging element, and guides a second light flux including the second fluorescence from the observation target irradiated with the second narrowband light to the second imaging element.

9. The medical observation system according to claim 7, wherein the light source device emits third narrowband light that excites a third substance that emits third fluorescence in a wavelength band that is not included in the first wavelength band and is at least partially different from the wavelength band of the second fluorescence, in a fourth mode different from the first mode and the second mode, the control section controls the light source device so that the wideband light and the third narrowband light are emitted to the observation target, and the optical element guides the first light flux including the reflected light from the observation target irradiated with the wideband light to the first imaging element, and guides the second light flux including the third fluorescence from the observation target irradiated with the third narrowband light to the second imaging element.

10. The medical observation system according to claim 7, wherein the light source device emits third narrowband light that excites a third substance that emits third fluorescence in a wavelength band that is not included in the first wavelength band and is at least partially different from the wavelength band of the second fluorescence, in a fifth mode different from the first mode and the second mode, the control section controls the light source device so that the wideband light and the first narrowband light are emitted to the observation target in a time-division manner, and the second narrowband light and the third narrowband light are emitted to the observation target in a time-division manner, and the optical element sequentially guides the first light flux including the reflected light from the observation target irradiated with the wideband light and the first light flux including the first fluorescence from the observation target irradiated with the first narrowband light to the first imaging element, and sequentially guides the second light flux including the second fluorescence from the observation target irradiated with the second narrowband light and the second light flux including the third fluorescence from the observation target irradiated with the third narrowband light to the second imaging element.

11. The medical observation system according to claim 2, wherein light in the wavelength band of the second fluorescence is partially, substantially, or completely suppressed in the first light flux.

12. The medical observation system according to claim 11, wherein the optical element is configured to: guide the first light flux in which light of the first wavelength band is partially suppressed to the first imaging element; and guide the second light flux in which light of the first wavelength band is partially suppressed to the second imaging element.

13. The medical observation system according to claim 12, further comprising: an image generation section that generates an image based on an image signal from the imaging section, wherein the control section controls the imaging section and the image generation section, in the first mode, the optical element sequentially guides the first light flux including the reflected light from the observation target irradiated with the wideband light and the first light flux including the first fluorescent light from the observation target irradiated with the first narrowband light to the first imaging element, and sequentially guides the second light flux including the reflected light from the observation target irradiated with the wideband light and the second light flux including the second fluorescent light from the observation target irradiated with the second narrowband light to the second imaging element, the control section controls the imaging section and the image generation section such that an image based on reflected light is generated from an image signal output from the first imaging element that has received the first light flux including the reflected light, and an image based on the second fluorescent light is generated from an image signal output from the second imaging element that has received the second light flux including the second fluorescent light, in the second mode, the optical element guides the first light flux including the reflected light from the observation target irradiated with the wideband light to the first imaging element, and sequentially guides the second light flux including the reflected light from the observation target irradiated with the wideband light and the second light flux including the second fluorescent light from the observation target irradiated with the second narrowband light to the second imaging element, and the control section controls the imaging section and the image generation section such that an image based on reflected light is generated from an image signal output from the first imaging element that has received the first light flux including the reflected light, and an image based on the second fluorescent light is generated from an image signal output from the second imaging element that has received the second light flux including the second fluorescent light.

14. The medical observation system according to claim 12, further comprising: an image generation section that generates an image based on an image signal from the imaging section, wherein the control section controls the imaging section and the image generation section, in a third mode different from the first mode and the second mode, the control section controls the light source device such that the wideband light, the first narrowband light, and the second narrowband light are emitted to the observation target in a time-division manner, the optical element sequentially guides the first light flux including the reflected light from the observation target irradiated with the wideband light and the first light flux including the first fluorescent light from the observation target irradiated with the first narrowband light to the first imaging element, and sequentially guides the second light flux including the reflected light from the observation target irradiated with the wideband light, the second light flux including the first fluorescent light from the observation target irradiated with the first narrowband light, and the second light flux including the second fluorescent light from the observation target irradiated with the second narrowband light to the second imaging element, and the control section controls the imaging section and the image generation section such that an image based on reflected light is generated from an image signal output from the first imaging element that has received the first light flux including the reflected light, and an image based on the second fluorescent light is generated from an image signal output from the second imaging element that has received the second light flux including the second fluorescent light. The control section controls the imaging section and the image generation section so that an image based on reflected light is generated from an image signal output from the first imaging element that has received the first light flux including reflected light, an image based on the first fluorescent light is generated from an image signal output from the second imaging element that has received the second light flux including the first fluorescent light, and an image based on the second fluorescent light is generated from an image signal output from the second imaging element that has received the second light flux including the second fluorescent light.

15. The medical observation system according to claim 11, wherein The optical element is configured to: direct the first light flux in which light within a wavelength band of the first fluorescent light is partially, substantially, or completely suppressed, to a first imaging element; and direct the second light flux in which a wavelength band other than the wavelength band of the first fluorescent light within the first wavelength band is partially, substantially, or completely suppressed, to the second imaging element.

16. The medical observation system according to claim 15, wherein The optical element is configured to: in the first mode, direct the first light flux including reflected light from the observation target irradiated with the wideband light to the first imaging element, and direct the second light flux including first fluorescent light from the observation target irradiated with the first narrowband light to the second imaging element; and in the second mode, direct the first light flux including reflected light from the observation target irradiated with the wideband light to the first imaging element, and direct the second light flux including second fluorescent light from the observation target irradiated with the second narrowband light to the second imaging element.

17. The medical observation system according to claim 16, wherein in a third mode different from the first mode and the second mode, the control section controls the light source device so that the wideband light is emitted to the observation target and the first narrowband light and the second narrowband light are emitted to the observation target in a time-division manner, and the optical element directs the first light flux including reflected light from the observation target irradiated with the wideband light to the first imaging element, and sequentially directs the second light flux including first fluorescent light from the observation target irradiated with the first narrowband light and the second light flux including second fluorescent light from the observation target irradiated with the second narrowband light to the second imaging element.

18. The medical observation system according to claim 4, wherein The second imaging element includes a color filter.

19. The medical observation system according to claim 18, wherein Light within a wavelength band of the second fluorescent light is partially, substantially, or completely suppressed in the first light flux.

20. The medical observation system according to claim 19, wherein The optical element is configured to: direct the first light flux in which light of the first wavelength band is partially suppressed, to the first imaging element; and directing the second light flux of the first wavelength band of light, which is partially suppressed, to the second imaging element.

21. The medical observation system according to claim 18, further comprising: an image generation section that generates an image based on an image signal from the imaging section, wherein the control section controls the imaging section and the image generation section, in the first mode, the optical element sequentially directs the first light flux including reflected light from the observation target irradiated with the wideband light and the first light flux including first fluorescent light from the observation target irradiated with the first narrowband light to the first imaging element, and sequentially directs the second light flux including reflected light from the observation target irradiated with the wideband light and the second light flux including second fluorescent light from the observation target irradiated with the second narrowband light to the second imaging element, the control section is configured to: control the imaging section and the image generation section so that an image based on reflected light is generated from one or both of an image signal output from the first imaging element that has received the first light flux including reflected light and an image signal output from the second imaging element that has received the second light flux including reflected light; and control the imaging section and the image generation section so that an image based on the first fluorescent light is generated from an image signal output from the second imaging element that has received the second light flux including the first fluorescent light, in the second mode, the optical element directs the first light flux including reflected light from the observation target irradiated with the wideband light to the first imaging element, and sequentially directs the second light flux including reflected light from the observation target irradiated with the wideband light and the second light flux including second fluorescent light from the observation target irradiated with the second narrowband light to the second imaging element, and the control section controls the imaging section and the image generation section so that an image based on reflected light is generated from an image signal output from the first imaging element that has received the first light flux including the reflected light, and an image based on the second fluorescent light is generated from an image signal output from the second imaging element that has received the second light flux including the second fluorescent light.

22. The medical observation system according to claim 18, further comprising: an image generation section that generates an image based on an image signal from the imaging section, wherein the control section controls the imaging section and the image generation section, in a third mode different from the first mode and the second mode, the control section controls the light source device so that the wideband light, the first narrowband light, and the second narrowband light are emitted to the observation target in a time-division manner, The optical element will direct the first light flux including the first fluorescent light from the observation target irradiated with the first narrow-band light to the second imaging element, and will direct a second light flux including the second fluorescent light from the observation target irradiated with the second narrow-band light to the third imaging element. The control section controls the imaging section and the image generation section so that an image based on the reflected light is generated from an image signal output from the first imaging element that has received the first light flux including the reflected light, an image based on the first fluorescent light is generated from an image signal output from the second imaging element that has received the second light flux including the first fluorescent light, and an image based on the second fluorescent light is generated from an image signal output from the second imaging element that has received the second light flux including the second fluorescent light.

23. The medical observation system according to claim 1, further comprising: an imaging section including a first imaging element, a second imaging element, and a third imaging element; and an optical element that separates light from the observation target into a plurality of light fluxes including a first light flux, a second light flux, and a third light flux, directs the first light flux to the first imaging element, directs the second light flux to the second imaging element, and directs the third light flux to the third imaging element.

24. The medical observation system according to claim 23, wherein the second imaging element and the third imaging element have higher sensitivity than the first imaging element.

25. The medical observation system according to claim 23, wherein the first imaging element includes a color filter.

26. The medical observation system according to claim 23, wherein the second imaging element and the third imaging element do not have a color filter.

27. The medical observation system according to claim 23, wherein light within a wavelength band of the second fluorescent light is partially, substantially, or completely suppressed in the first light flux, light within a wavelength band of the second fluorescent light is partially, substantially, or completely suppressed in the second light flux, and light within the first wavelength band is partially, substantially, or completely suppressed in the third light flux.

28. The medical observation system according to claim 23, wherein the optical element is configured to: in the first mode, direct the first light flux including the reflected light from the observation target irradiated with the wide-band light to the first imaging element, and direct the second light flux including the first fluorescent light from the observation target irradiated with the first narrow-band light to the second imaging element; and in the second mode, direct the second light flux including the first fluorescent light from the observation target irradiated with the first narrow-band light to the third imaging element, and direct the third light flux including the second fluorescent light from the observation target irradiated with the second narrow-band light to the second imaging element. In the second mode, the first light flux including reflected light from the observation target irradiated with the wideband light is guided to the first imaging element, and the third light flux including second fluorescent light from the observation target irradiated with the second narrowband light is guided to the third imaging element.

29. The medical observation system according to claim 28, wherein in a third mode different from the first mode and the second mode, the control section controls the light source device such that the wideband light and the first narrowband light are emitted to the observation target in a time-division manner, and the second narrowband light is emitted to the observation target, and the optical element guides the first light flux including reflected light from the observation target irradiated with the wideband light to the first imaging element, guides the second light flux including first fluorescent light from the observation target irradiated with the first narrowband light to the second imaging element, and guides the third light flux including second fluorescent light from the observation target irradiated with the second narrowband light to the third imaging element.

30. The medical observation system according to claim 28, wherein the light source device emits third narrowband light that excites a third substance that emits third fluorescent light in a wavelength band that is not included in the first wavelength band and is at least partially different from a wavelength band of the second fluorescent light, in a fourth mode different from the first mode and the second mode, the control section controls the light source device such that the wideband light and the third narrowband light are emitted to the observation target, and the optical element guides the first light flux including reflected light from the observation target irradiated with the wideband light to the first imaging element, and guides the third light flux including third fluorescent light from the observation target irradiated with the third narrowband light to the third imaging element.

31. The medical observation system according to claim 28, wherein the light source device emits third narrowband light that excites a third substance that emits third fluorescent light in a wavelength band that is not included in the first wavelength band and is at least partially different from a wavelength band of the second fluorescent light, in a fifth mode different from the first mode and the second mode, the control section controls the light source device such that the wideband light and the first narrowband light are emitted to the observation target in a time-division manner, and the second narrowband light and the third narrowband light are emitted to the observation target in a time-division manner, and the optical element guides the first light flux including reflected light from the observation target irradiated with the wideband light to the first imaging element, guides the second light flux including first fluorescent light from the observation target irradiated with the first narrowband light to the second imaging element, and guides the third light flux including second fluorescent light from the observation target irradiated with the second narrowband light to the third imaging element. The optical element directs the first light flux including reflected light from the observation target irradiated with the wideband light to the first imaging element, directs the second light flux including first fluorescence from the observation target irradiated with the first narrowband light to the second imaging element, and sequentially directs the third light flux including second fluorescence from the observation target irradiated with the second narrowband light and the third light flux including third fluorescence from the observation target irradiated with the third narrowband light to the third imaging element.

32. The medical observation system according to claim 23, wherein light within the wavelength band of the second fluorescence is partially, substantially, or completely suppressed in the first light flux, light within the first wavelength band is partially, substantially, or completely suppressed in the second light flux, and light within the first wavelength band is partially, substantially, or completely suppressed in the third light flux.

33. The medical observation system according to claim 32, wherein the optical element is configured to: in the first mode, sequentially direct the first light flux including reflected light from the observation target irradiated with the wideband light and the first light flux including first fluorescence from the observation target irradiated with the first narrowband light to the first imaging element; and in the second mode, direct the first light flux including reflected light from the observation target irradiated with the wideband light to the first imaging element, and direct the second light flux including second fluorescence from the observation target irradiated with the second narrowband light to the second imaging element.

34. The medical observation system according to claim 33, wherein in a third mode different from the first mode and the second mode, the control section controls the light source apparatus such that the wideband light and the first narrowband light are emitted to the observation target in a time-division manner, and the second narrowband light is emitted to the observation target, and the optical element sequentially directs the first light flux including reflected light from the observation target irradiated with the wideband light and the first light flux including first fluorescence from the observation target irradiated with the first narrowband light to the first imaging element, and directs the second light flux including second fluorescence from the observation target irradiated with the second narrowband light to the second imaging element.

35. The medical observation system according to claim 33, wherein in a fourth mode different from the first mode and the second mode, the control section controls the light source apparatus such that the wideband light and the third narrowband light are emitted to the observation target, and the optical element directs the first light flux including reflected light from the observation target irradiated with the wideband light to the first imaging element, and directs the second light flux including third fluorescence from the observation target irradiated with the third narrowband light to the second imaging element.

36. The medical observation system according to claim 33, wherein the light source device emits third narrow-band light that excites a third substance that emits third fluorescent light in a wavelength band that is not included in the first wavelength band and at least partially coincides with the wavelength band of the second fluorescent light, in a fourth mode different from the first mode and the second mode, the control section controls the light source device such that the wide-band light and the third narrow-band light are emitted to the observation target, and the optical element guides the first light flux including the reflected light from the observation target irradiated with the wide-band light to the first imaging element, and guides the third light flux including the third fluorescent light from the observation target irradiated with the third narrow-band light to the third imaging element.

37. The medical observation system according to claim 33, further comprising: an image generation section that generates an image based on an image signal from the imaging section, wherein the control section controls the imaging section and the image generation section, the light source device emits third narrow-band light that excites a third substance that emits third fluorescent light in a wavelength band that is not included in the first wavelength band and at least partially coincides with the wavelength band of the second fluorescent light, in a fifth mode different from the first mode and the second mode, the control section controls the light source device such that the wide-band light is emitted to the observation target and the second narrow-band light and the third narrow-band light are emitted to the observation target in a time-division manner, the optical element guides the first light flux including the reflected light from the observation target irradiated with the wide-band light to the first imaging element, guides the second light flux including the second fluorescent light from the observation target irradiated with the second narrow-band light and the second light flux including the third fluorescent light from the observation target irradiated with the third narrow-band light to the second imaging element in order, and guides the third light flux including the second fluorescent light from the observation target irradiated with the second narrow-band light and the third light flux including the third fluorescent light from the observation target irradiated with the third narrow-band light to the third imaging element in order, and the control section controls the imaging section and the image generation section such that an image based on the reflected light is generated from an image signal output from the first imaging element that has received the first light flux including the reflected light, an image based on the second fluorescent light is generated from an image signal output from the second imaging element that has received the second light flux including the second fluorescent light, and image data of the third fluorescent light is generated from an image signal output from the third imaging element that has received the third light flux including the third fluorescent light.

38. The medical observation system according to claim 33, further comprising: an image generation section that generates an image based on an image signal from the imaging section, wherein the control section controls the imaging section and the image generation section, the light source device emits third narrowband light that excites a third substance that emits third fluorescent light in a wavelength band that is not included in the first wavelength band and at least partially coincides with the wavelength band of the second fluorescent light, in a sixth mode that is different from the first mode and the second mode, the control section controls the light source device such that the wideband light and the first narrowband light are emitted to the observation target in a time-division manner, and the second narrowband light and the third narrowband light are emitted to the observation target in a time-division manner, the optical element sequentially guides the first light flux including reflected light from the observation target irradiated with the wideband light and the first light flux including first fluorescent light from the observation target irradiated with the first narrowband light to the first imaging element, sequentially guides the second light flux including second fluorescent light from the observation target irradiated with the second narrowband light and the second light flux including third fluorescent light from the observation target irradiated with the third narrowband light to the second imaging element, and sequentially guides third light flux including second fluorescent light from the observation target irradiated with the second narrowband light and third light flux including third fluorescent light from the observation target irradiated with the third narrowband light to the third imaging element, and the control section controls the imaging section and the image generation section such that an image based on reflected light is generated from an image signal output from the first imaging element that has received the first light flux including reflected light, an image based on the first fluorescent light is generated from an image signal output from the first imaging element that has received the first light flux including the first fluorescent light, an image based on the second fluorescent light is generated from an image signal output from the second imaging element that has received the second light flux including the second fluorescent light, and image data of the third fluorescent light is generated from an image signal output from the third imaging element that has received the third light flux including the third fluorescent light.

39. The medical observation system according to claim 23, wherein the first imaging element and the second imaging element include color filters.

40. The medical observation system according to claim 23, wherein the third imaging element does not have a color filter.

41. The medical observation system according to claim 39, wherein light in the wavelength band of the second fluorescent light is partially, substantially, or completely suppressed in the first light flux, light in the wavelength band of the second fluorescent light is partially, substantially, or completely suppressed in the second light flux, and light in the first wavelength band is partially, substantially, or completely suppressed in the third light flux.

42. The medical observation system according to claim 41, further comprising: an image generation section that generates an image based on an image signal from the imaging section, wherein the control section controls the imaging section and the image generation section, in the first mode, the optical element sequentially guides the first light flux including reflected light from the observation target irradiated with the first narrow-band light to the first imaging element and the second light flux including reflected light from the observation target irradiated with the first narrow-band light to the second imaging element, the control section is configured to: control the imaging section and the image generation section so that an image based on reflected light is generated from one or both of an image signal output from the first imaging element that has received the first light flux including reflected light and an image signal output from the second imaging element that has received the second light flux including reflected light; and control the imaging section and the image generation section so that an image based on the first fluorescent light is generated from an image signal output from the second imaging element that has received the second light flux including the first fluorescent light, in the second mode, the optical element guides the first light flux including reflected light from the observation target irradiated with the first narrow-band light to the first imaging element, guides the second light flux including reflected light from the observation target irradiated with the first narrow-band light to the second imaging element, and guides the third light flux including second fluorescent light from the observation target irradiated with the second narrow-band light to the third imaging element, and the control section is configured to: control the imaging section and the image generation section so that an image based on reflected light is generated from one or both of an image signal output from the first imaging element that has received the first light flux including reflected light and an image signal output from the second imaging element that has received the second light flux including reflected light; and control the imaging section and the image generation section so that an image based on the second fluorescent light is generated from an image signal output from the third imaging element that has received the third light flux including the second fluorescent light.

43. The medical observation system according to claim 39, further comprising: an image generation section that generates an image based on an image signal from the imaging section, wherein the control section controls the imaging section and the image generation section, in a third mode different from the first mode and the second mode, the control section controls the light source device so that the wide-band light and the first narrow-band light are emitted to the observation target in a time-division manner, and the second narrow-band light is emitted to the observation target, The optical element sequentially guides the first light flux including reflected light from the observation target irradiated with the wideband light and the first light flux including first fluorescent light from the observation target irradiated with the first narrowband light to the first imaging element, sequentially guides the second light flux including reflected light from the observation target irradiated with the wideband light and the second light flux including first fluorescent light from the observation target irradiated with the first narrowband light to the second imaging element, and guides a third light flux including second fluorescent light from the observation target irradiated with second narrowband light to a third imaging element, and The control section is configured to: control the imaging section and the image generation section so that an image based on reflected light is generated from one or both of an image signal output from the first imaging element that has received the first light flux including reflected light and an image signal output from the second imaging element that has received the second light flux including reflected light; control the imaging section and the image generation section so that an image based on the first fluorescent light is generated from an image signal output from the second imaging element that has received the second light flux including the first fluorescent light; and control the imaging section and the image generation section so that an image based on the second fluorescent light is generated from an image signal output from the third imaging element that has received the third light flux including the second fluorescent light. The first wavelength band is included in a visible light wavelength band.

44. The medical observation system of claim 1, wherein, The wavelength of the second fluorescent light is included in an invisible light wavelength band.

45. The medical observation system of claim 1, wherein, The first imaging element has a higher resolution than the second imaging element.

46. The medical observation system of claim 2, wherein, a filter element that partially, substantially, or completely suppresses light in the wavelength band of the first narrowband light.

47. The medical observation system of claim 1, further comprising: a filter element that partially, substantially, or completely suppresses light in the wavelength band of the second narrowband light.

48. The medical observation system of claim 1, further comprising:

49. The medical observation system according to claim 21, further comprising: an instruction receiving section that receives an instruction from a user, the control section determines whether to generate an image based on the reflected light using one or both of the image signal output from the first imaging element and the image signal output from the second imaging element in accordance with the instruction from the user received by the instruction receiving section.

50. The medical observation system according to claim 43, further comprising: an instruction receiving section that receives an instruction from a user, the control section determines whether to generate an image based on the reflected light using one or both of the image signal output from the first imaging element and the image signal output from the second imaging element in accordance with the instruction from the user received by the instruction receiving section.

51. The medical observation system according to claim 1, further comprising: an image generation section that generates an image based on an image signal from an imaging section that captures an image of the observation target, wherein ​ Under the control of the control section, in a case where the mode is switched from one of the first mode and the second mode to the other mode, the image generation section uses at least some of the parameters used in the one mode while maintaining the other mode.

52. The medical observation system of claim 51, wherein The parameter is a parameter related to at least one of white balance, tone, and color mode.

53. A medical observation method comprising: a step of emitting at least one of wideband light within a first wavelength band, first narrowband light that excites a first substance that emits first fluorescent light within a wavelength band included in the first wavelength band, and second narrowband light that excites a second substance that emits second fluorescent light within a wavelength band not included in the first wavelength band, from a light source device, wherein in a first mode, the wideband light and the first narrowband light are emitted from the light source device so that the wideband light and the first narrowband light are emitted to an observation target in a time-division manner, and in a second mode different from the first mode, the wideband light and the second narrowband light are emitted from the light source device so that the observation target is irradiated with the wideband light and the second narrowband light.

Images