Imaging device and medical observation system

Abstract

The imaging apparatus includes: a prism that separates visible light and fluorescent light included in light from an object to be observed; a visible light imaging element that images the visible light separated by the prism; and a fluorescence imaging element that images the fluorescence separated by the prism, in which a ratio of a pixel pitch of the fluorescence imaging element to a pixel pitch of the visible light imaging element is at least 1 but less than 5.

Description

Technical Field

[0001] The present disclosure relates to imaging devices and medical observation systems. Background Art

[0002] For example, Patent Document 1 discloses a technique of separating visible light and fluorescence from an observation object to capture them with different imaging elements.

[0003] Reference List

[0004] Patent Literature

[0005] Patent Document 1: JP 2017-53890A Summary of the invention

[0006] Technical issues

[0007] When the number of pixels of an imaging element is increased for high-resolution imaging, the light receiving area per pixel is narrowed by the increased number of pixels, and the sensitivity may be insufficient. Specifically, it is difficult to clearly capture fluorescence because fluorescence is weaker than visible light. There is still a need to study the technology that can capture visible light with high resolution and clearly capture fluorescence.

[0008] One aspect of the present disclosure is the ability to capture visible light with high resolution and to clearly capture fluorescent light.

[0009] Solution to the problem

[0010] According to one aspect of the present disclosure, an imaging device includes: a prism that separates visible light and fluorescence included in light from an observed object; a visible light imaging element that captures the visible light separated by the prism; and a fluorescence imaging element that captures the fluorescence separated by the prism, wherein a ratio of a pixel pitch in the fluorescence imaging element to a pixel pitch in the visible light imaging element is greater than 1 and less than 5.

[0011] A medical observation system according to one aspect of the present disclosure includes an imaging device that captures a surgical site, wherein the imaging device includes: a prism that separates visible light and fluorescence included in light from the surgical site; a visible light imaging element that captures the visible light separated by the prism; and a fluorescence imaging element that captures the fluorescence separated by the prism, and a ratio of a pixel pitch in the fluorescence imaging element to a pixel pitch in the visible light imaging element is greater than 1 and less than 5. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 is a diagram showing an example of a schematic configuration of an imaging device according to the first embodiment.

[0013] Figure 2is a graph showing an example of the characteristics of the dichroic film 65 .

[0014] Figure 3 is a diagram showing an example of a schematic configuration of a visible light imaging element.

[0015] Figure 4 is a diagram showing an example of a pixel pitch in a visible light imaging element.

[0016] Figure 5 is a diagram showing an example of a pixel pitch in a visible light imaging element.

[0017] Figure 6 is a graph showing an example of the characteristics of a long pass filter.

[0018] Figure 7 is a diagram showing an example of a schematic configuration of a fluorescence imaging element.

[0019] Figure 8 is a diagram showing an example of a pixel pitch in a fluorescent imaging element.

[0020] Fig. 9 is a diagram showing an example of a pixel pitch in a fluorescent imaging element.

[0021] Fig.10 2 is a diagram showing an example of a retaining member.

[0022] Fig.11 is a diagram showing an example of a schematic configuration of an imaging device according to the second embodiment.

[0023] Fig.12 is a graph showing an example of the characteristics of the dichroic film 66 .

[0024] Fig.13 is a diagram showing an example of a schematic configuration of an imaging device according to a third embodiment.

[0025] Fig.14 is a diagram showing an example of the characteristics of the dichroic film 67 .

[0026] Fig.15 is a diagram showing an example of the characteristics of the dichroic film 68 .

[0027] Fig.16 is a diagram showing an example of the characteristics of the dichroic film 69 .

[0028] Fig.17 is a diagram showing an example of a schematic configuration of an endoscope system.

[0029] Fig.18It shows that Fig.17 A block diagram of an embodiment of a functional configuration of a camera and a camera control unit (CCU) is shown in FIG.

[0030] Fig.19 is a diagram showing an example of a schematic configuration of a microscope surgery system. DETAILED DESCRIPTION

[0031] Embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. Note that in the following embodiments, the same elements will be denoted by the same reference numerals, and description thereof will not be repeated.

[0032] Furthermore, the present disclosure will be described in the order of items shown below.

[0033] 0. Introduction

[0034] 1. First Implementation

[0035] 2. Second Implementation

[0036] 3. Third Implementation

[0037] 4. Modifications

[0038] 5. Application examples

[0039] 6. Effect examples

[0040] 0. Introduction

[0041] For example, in a medical endoscope, a wavelength separation prism is used to separate visible light (ordinary light) and fluorescence (special light), so that the corresponding imaging element receives the visible light and the fluorescence. Examples of visible light include green light, blue light, and red light. Examples of fluorescence include infrared light (e.g., near infrared light), etc. Note that, hereinafter, the wavelength separation prism is referred to as a "prism".

[0042] For example, in a three-plate prism configuration in which green light, blue light, red light, and near-infrared light are separated and captured, three monochrome imaging elements of a similar configuration are used. Red light and near-infrared light are received in a time-division manner, and due to the time division, the responsiveness is reduced. In a two-plate prism configuration in which visible light and fluorescence are separated and captured, the fluorescence is weak (low brightness), and therefore when the same imaging element as that for visible light is used, the sensitivity is insufficient. Even if an attempt is made to clearly observe the fluorescence by increasing the gain, etc., the S / N ratio is reduced, and it is better to say that the image quality deteriorates. In addition, weak fluorescence causes a halo of visible light (leakage light) that cannot be completely separated by the dichroic film of the prism, reducing the contrast.

[0043] At least some of the problems described above can be solved by the disclosed technology. For example, visible light and fluorescence can be separated by a prism according to wavelength so as to be simultaneously received by multiple imaging elements having different wavelength band sensitivities (color or monochrome), pixel sizes, imaging sizes, etc. For example, fluorescence is near-infrared light that is weaker than visible light, and this light can be captured clearly. A long-pass filter (trimming filter) can be arranged between the prism and the fluorescence imaging element to block visible light that has not been separated by the prism according to wavelength and is unnecessary for capturing fluorescence. The fluorescence imaging element can have an imaging size that is smaller than the imaging size of the visible light imaging element. Each of the imaging elements is arranged at a focusing position of an imaging lens system (imaging lens, etc.). The imaging device can be used in combination with an LED light source, an excitation laser light source, etc. The imaging device can be used in combination with a rigid endoscope, a microscope, etc.

[0044] 1. First Implementation

[0045] Figure 1 1 is a diagram showing an example of a schematic configuration of an imaging device according to a first embodiment. The imaging device 1 captures an observation object S (subject). Figure 1 Schematically shows a side view of an observation object S and elements of an imaging device 1. The imaging device 1 captures light from the observation object S. Note that it can be understood that "capture" includes "shooting", and "image" includes "video". As long as there is no contradiction, capture and image can be appropriately replaced with shooting and video, respectively.

[0046] Observation of the observation object S includes visible light observation and fluorescence observation, and therefore, capturing the observation object S by the imaging device 1 includes capturing visible light and capturing fluorescence. Hereinafter, unless otherwise described, fluorescence includes infrared light.

[0047] The imaging device 1 comprises a light source 2, an optical diagnosis component 3, an imaging lens 4, an excitation light cutoff filter 5, a prism 6, a visible light imaging element 7, a long pass filter 8 and a fluorescence imaging element 9. In addition, several light rays are schematically indicated by white arrows.

[0048] The light source 2 outputs light SL. The light SL includes white light WL and excitation light EL. The excitation light EL is, for example, near-infrared light, and the excitation light EL as near-infrared light may be laser light having a wavelength of about 780±30 nm. Figure 1 In the illustrated embodiment, the light source 2 includes a white light source 21 and an excitation light source 22. The white light source 21 outputs white light WL. The white light source 21 may include a light emitting diode (LED) that emits white light, or may include a light emitting LED that emits red light, an LED that emits green light, and an LED that emits blue light (RGB-LED). The excitation light source 22 outputs excitation light EL.

[0049] The optical diagnostic component 3 guides the light SL from the light source 2 (i.e., the white light WL from the white light source 21 and the excitation light EL from the excitation light source 22) to the observation object S. The optical diagnostic component 3 can constitute a part of an imaging system (medical observation system) including, for example, a laparoscope, a rigid endoscope, a flexible endoscope, a camera, an operating microscope, etc. For example, the optical diagnostic component 3 may include an optical system for transmitting light, a housing for accommodating the optical system, etc. The light SL from the light source 2 is applied to the observation object S via the optical diagnostic component 3.

[0050] The observation object S is illuminated by applying the white light WL included in the light SL. In addition, a reagent excited by applying the excitation light EL included in the light SL is injected into the observation object S. Due to these illuminations and excitations, light L including visible light VL and fluorescence FL is induced in the observation object S. The visible light VL is light reflected from the observation object S to which the white light WL is applied. The fluorescence FL is fluorescence emitted from the reagent injected into the observation object S and excited by the excitation light EL.

[0051] The optical diagnostic component 3 guides the light L (i.e., visible light VL and fluorescence FL) from the observation object S to the prism 6, more specifically, in this embodiment, to the imaging lens 4 provided on the upstream side (near the observation object S) of the prism 6. The light L from the observation object S is input into the imaging lens 4 via the optical diagnostic component 3.

[0052] The imaging lens 4 is disposed between the observation object S and the prism 6, and more specifically, in this embodiment, between the optical diagnosis component 3 and the excitation light cutoff filter 5. The imaging lens 4 includes, for example, one or more condensing lenses, etc. In the imaging lens 4, the input surface to which the light L from the observation object S is input is referred to as the input surface 4a in the figure. The output surface from which the light L is output is referred to as the output surface 4b in the figure. The light L from the output surface 4b of the imaging lens 4 is input to the excitation light cutoff filter 5.

[0053] The excitation light cutoff filter 5 is arranged between the observation object S and the prism 6, and more specifically, in this embodiment, is arranged between the imaging lens 4 and the prism 6. When the excitation light EL is included in the light L, the excitation light cutoff filter 5 reflects or attenuates the excitation light EL and transmits the visible light VL and the fluorescence FL. In the excitation light cutoff filter 5, the surface to which the light L is input is referred to as the input surface 5a in the figure. The surface to which the light L is output is referred to as the output surface 5b in the figure. The light L from the output surface 5b is input into the prism 6. Note that as long as there is no contradiction, "transmission" can be understood as the meaning of "transmittance", and "transmission" and "transmittance" can be appropriately replaced with each other.

[0054] The prism 6 separates and outputs the light L from the observation object S, and more specifically, in this embodiment, separates and outputs the visible light VL and the fluorescence FL included in the light L transmitted by the imaging lens 4 and the excitation light cutoff filter 5. The prism 6 includes a block 61, a block 62, and a dichroic film 65. In the prism 6, the surface to which the incident light L is input is referred to as an input surface 6a in the figure. The surface to which the visible light VL is output is referred to as an output surface 6b1 in the figure. The surface to which the fluorescence FL is output is referred to as an output surface 6b2 in the figure. The output surface 6b1 is a portion of the surface of the block 61. The output surface 6b2 is a portion of the surface of the block 62.

[0055] The dichroic film 65 is disposed between the block 61 and the block 62 so that the light L from the input surface 6a of the prism 6 is input. In this embodiment, the dichroic film 65 is formed in the block 61. The dichroic film 65 reflects the visible light VL and transmits the fluorescent light FL. Figure 2 Give a description.

[0056] Figure 2 is a graph showing an example of the characteristics of the dichroic film 65. The horizontal axis of the graph represents the wavelength. The vertical axis of the graph represents the transmittance and reflectance (%). The reflectance is high in the wavelength band of the visible light VL, and the transmittance is high in the wavelength band of the fluorescent light FL.

[0057] return Figure 1 , the block 61 of the prism 6 is a prism block (first block) that guides the visible light VL to the visible light imaging element 7. The block 61 outputs the visible light VL reflected by the dichroic film 65 from the output surface 6b1. The block 62 is a prism block (second block) that guides the fluorescence FL to the fluorescence imaging element 9. The block 62 outputs the fluorescence FL transmitted by the dichroic film 65 from the output surface 6b2.

[0058] Visible light VL output from the output surface 6b1 of the prism 6 is imaged and captured by the visible light imaging element 7. The visible light imaging element 7 is directly or indirectly fixed to the prism 6 to be located at an imaging position of the visible light VL.

[0059] The visible light imaging element 7 captures the visible light VL from the prism 6. The visible light imaging element 7 includes a light receiving surface 7a. The visible light imaging element 7 is arranged so that the light receiving surface 7a is opposite to the output surface 6b1 of the prism 6. In this embodiment, the visible light imaging element 7 is arranged (bonded, etc.) on the output surface 6b1 of the block 61 of the prism 6. The visible light imaging element 7 is, for example, a complementary metal oxide semiconductor (CMOS) image sensor designed to capture the visible light VL.

[0060] In the first embodiment, the pixel pitch (pixel interval) in the visible light imaging element 7 is referred to as the pixel pitch P1. The effective pixel area diagonal length of the visible light imaging element 7 is referred to as the effective pixel area diagonal length D1. Figures 3 to 5 A further description is given.

[0061] Figure 3 is a diagram showing an embodiment of a schematic configuration of a visible light imaging element. A front view of a visible light imaging element 7 is schematically shown. The visible light imaging element 7 includes a plurality of pixels 7p. Each of the pixels 7p is designed to efficiently receive visible light. For example, the plurality of pixels 7p include a pixel that receives blue light, a pixel that receives red light, and a pixel that receives green light. Each pixel 7p includes a filter that transmits light of a corresponding color, a photoelectric conversion element that receives light transmitted by the filter and generates a charge according to the amount of light received, and a transistor (pixel circuit, etc.) that controls light reception of the photoelectric conversion element or extracts an electrical signal according to the charge. Embodiments of the pixel array include, but are not limited to, a Bayer array, but various known pixel arrays may be employed.

[0062] The visible light imaging element 7 includes a pixel area 7a1 and an effective pixel area 7a2. The effective pixel area 7a2 is an area within the pixel area 7a1, which is narrower than the pixel area 7a1. A plurality of pixels 7p are arranged in an array throughout the pixel area 7a1 to define a light receiving surface 7a. Among these pixels 7p, the pixels 7p arranged in the effective pixel area 7a2 are effective pixels actually used for image capture. The diagonal length of the effective pixel area 7a2 is the effective pixel area diagonal length D1. As the effective pixel area diagonal length D1 increases, the effective pixel area 7a2 also increases. In this sense, the effective pixel area diagonal length D1 can be appropriately replaced by the effective pixel area 7a2, or can be replaced by the meaning of the size of the visible light imaging element 7.

[0063] Figure 4 and Figure 5 1 and 2 are diagrams each showing an embodiment of a pixel pitch in a visible light imaging element. For ease of understanding, only four pixels 7p are shown. The pixels 7p may be as follows: Figure 4 As shown, they can be arranged side by side in the horizontal and vertical directions, or they can be arranged as shown in Figure 5 As shown, the pixels 7p are arranged side by side in an oblique direction (a direction between the vertical direction and the horizontal direction). In this embodiment, each of the pixels 7p has a square shape, and the length of one side thereof defines the size of the pixel 7p. The size of the pixel 7p is referred to as the pixel size W1 in the figure. The distance between the centers of adjacent pixels 7p is the pixel pitch P1. As the pixel pitch P1 increases, the pixel size W1 also increases. In this sense, the pixel pitch P1 can be appropriately replaced by the pixel size W1.

[0064] If the effective pixel area diagonal length D1 is the same (the visible light imaging element 7 has the same size), the resolution increases as the pixel pitch P1 decreases. The resolution decreases as the pixel pitch P1 increases.

[0065] return Figure 1 , the fluorescence FL from the output surface 6b2 of the prism 6 is input into the long-pass filter 8.

[0066] The long-pass filter 8 is disposed between the block 62 of the prism 6 and the fluorescence imaging element 9. The long-pass filter 8 transmits the fluorescence FL and reflects or attenuates the visible light VL. Unnecessary visible light VL that is not separated by the prism 6 may cause halos, and a clear image of the fluorescence FL may not be obtained. The long-pass filter 8 is provided to suppress such unnecessary visible light VL from being input into the fluorescence imaging element 9. A high-quality image with a high S / N ratio can be obtained. In the long-pass filter 8, the surface to which the fluorescence FL is input is referred to as the input surface 8a in the figure. The surface from which the fluorescence FL is output is referred to as the output surface 8b in the figure. Further reference will be made to Figure 6 The long pass filter 8 is described.

[0067] Figure 6 is a graph showing an embodiment of the characteristics of a long pass filter. The graph shows low transmittance (a large amount of reflection or attenuation) in the wavelength band of visible light VL and high transmittance (a small amount of reflection or attenuation) in the wavelength band of fluorescent light FL. For example, the long pass filter 8 transmits more than 90% of light with a wavelength of at least 750nm to 850nm, and attenuates light with a wavelength of 400nm to 600nm to less than 10%. More specifically, the long pass filter 8 can transmit more than 90% of light with a wavelength of at least 820nm to 850nm, and attenuate light with a wavelength of 400nm to 600nm to less than 10%. For the visible light VL input to the input surface 6a of the prism 6, the optical density of the visible light VL output from the output surface 8b of the long pass filter 8 can be OD3 or more.

[0068] return Figure 1 , the input surface 8a of the long pass filter 8 may be a surface perpendicular to the optical axis. The long pass filter 8 is disposed at the prism 6 so that the input surface 8a faces the output surface 6b2 of the block 62 of the prism 6. Figure 1 In the embodiment shown in FIG. 8 , the long pass filter 8 is disposed (eg, bonded) on the output surface 6 b 2 of the block 62 of the prism 6 .

[0069] Fluorescence FL from the output surface 6b2 of the prism 6, more specifically, fluorescence FL from the output surface 8b of the long pass filter 8 in this embodiment is imaged and captured by the fluorescence imaging element 9. The fluorescence imaging element 9 is directly or indirectly fixed to the prism 6 to be located at the imaging position of the fluorescence FL.

[0070] The fluorescence imaging element 9 captures the fluorescence FL from the prism 6. The fluorescence imaging element 9 includes a light receiving surface 9a. The fluorescence imaging element 9 is arranged so that the light receiving surface 9a faces the output surface 6b2 of the prism 6. In this embodiment, the fluorescence imaging element 9 is arranged (e.g., bonded) on the output surface 8b of the long pass filter 8 to face the output surface 8b of the long pass filter 8. The fluorescence imaging element 9 is, for example, a complementary metal oxide semiconductor (CMOS) image sensor designed to capture the fluorescence FL.

[0071] The pixel pitch in the fluorescence imaging element 9 is referred to as the pixel pitch P2. The effective pixel area diagonal length of the fluorescence imaging element 9 is referred to as the effective pixel area diagonal length D2. Figures 7 to 9 A further description is given.

[0072] Figure 7 is a diagram showing an embodiment of a schematic configuration of a fluorescent imaging element. A front view of a fluorescent imaging element 9 is schematically shown. The fluorescent imaging element 9 includes a plurality of pixels 9p. Each of the pixels 9p is designed to efficiently receive fluorescent light FL. Each pixel 9p includes a filter that transmits fluorescent light FL, a photoelectric conversion element that receives light transmitted by the filter and generates electric charge according to the amount of light received, and a transistor (pixel circuit, etc.) that controls light reception of the photoelectric conversion element or extracts an electric signal according to the charge. The pixel array can adopt various known pixel arrays.

[0073] Fluorescence imaging element 9 includes pixel area 9a1 and effective pixel area 9a2. A plurality of pixels 9p are arranged in an array over the entire pixel area 9a1 to define a light receiving surface 9a. Among these pixels 9p, the pixels 9p arranged in the effective pixel area 9a2 are effective pixels actually used for image capture. The diagonal length of the effective pixel area 9a2 is the effective pixel area diagonal length D2. If the effective pixel area diagonal length D2 is the same (fluorescence imaging element 9 has the same size), the resolution increases as the pixel pitch P2 decreases. As the pixel pitch P2 increases, the resolution decreases.

[0074] Figure 8 and Fig. 9 9p are diagrams each showing an example of a pixel pitch in a fluorescent imaging element. Figure 8 As shown, they can be arranged side by side in the horizontal and vertical directions, or they can be arranged as shown in Fig. 9 The pixel size 9p is shown arranged side by side in an oblique direction. The size of the pixel 9p is referred to as the pixel size W2 in the figure. The distance between the centers of adjacent pixels 9p is the pixel pitch P2. As the pixel size W2 increases, the pixel pitch P2 also increases.

[0075] return Figure 1 In the above-mentioned imaging device 1, the visible light VL and the fluorescence FL from the observation object S are separated by the prism 6 and captured by the visible light imaging element 7 and the fluorescence imaging element 9, respectively, and the visible light observation and the fluorescence observation of the observation object S are performed. Here, since the fluorescence FL is weaker than the visible light VL, etc., there is a possibility that the sensitivity of the fluorescence imaging element 9 is insufficient and clear fluorescence observation cannot be performed. The imaging device 1 according to the first embodiment is designed to capture the visible light VL with high resolution and clearly capture the fluorescence FL. Several design conditions will be described. Note that among the design conditions described below, non-exclusive design conditions can be appropriately combined.

[0076] <Design Conditions 1-1>

[0077] In one embodiment, the ratio (P2 / P1) of the pixel pitch P2 in the fluorescent imaging element 9 to the pixel pitch P1 in the visible light imaging element 7 may be 1 or more and less than 5. In other words, the pixel pitch P1 in the visible light imaging element 7 and the pixel pitch P2 in the fluorescent imaging element 9 may be designed to satisfy the following conditional expression (1).

[0078]

[0079] When the ratio (P2 / P1) drops below 1, the pixel size W2 of the fluorescence imaging element 9 decreases, the amount of light captured in each pixel 9p of the weak fluorescence FL decreases, and the noise in the captured image increases. When the ratio (P2 / P1) is 5 or more, the pixel size W2 of the fluorescence imaging element 9 increases, and the size of the imaging device 1 increases. When the number of pixels 9p is reduced to prevent the size of the imaging device 1 from increasing, the resolution decreases.

[0080] When the ratio (P2 / P1) is greater than 1, the pixel size W2 of the fluorescence imaging element 9 increases and the light input amount increases, and weak fluorescence FL can be received with high sensitivity to clearly capture the fluorescence FL. When the ratio (P2 / P1) is 1, for example, using a color imaging element as the visible light imaging element 7 and using a monochrome imaging element as the fluorescence imaging element 9 makes it possible to receive the fluorescence FL with high sensitivity and clearly capture the fluorescence FL while maintaining the same resolution.

[0081] Note that the lower limit value of the ratio (P2 / P1) may be greater than the value expressed in the above conditional expression (1). Examples of such lower limit values ​​are 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, etc. In addition, the upper limit value thereof may be less than the value expressed in the above conditional expression (1). Examples of such upper limit values ​​are 4.8, 4.6, 4.4, 4.2, 4.0, 3.8, 3.6, 3.4, 3.2, 3.0, 2.8, 2.6, 2.4, 2.2, 2.0, 1.8, 1.6, etc.

[0082] <Design conditions 1-2>

[0083] In one embodiment, the ratio (D2 / D1) of the effective pixel area diagonal length D2 of the fluorescence imaging element 9 to the effective pixel area diagonal length D1 of the visible light imaging element 7 may be greater than 0.7 and less than 1.4. In other words, the effective pixel area diagonal length D1 of the visible light imaging element 7 and the effective pixel area diagonal length D2 of the fluorescence imaging element 9 may be designed to satisfy the following conditional expression (2).

[0084]

[0085] When the ratio (D2 / D1) is 0.7 or less, the viewing angle of the fluorescent imaging element 9 is significantly reduced compared to the viewing angle of the visible light imaging element 7, and the field of view in which the fluorescent light FL can be observed is limited. When the ratio (D2 / D1) is 1.4 or more, the viewing angle of the fluorescent imaging element 9 is significantly increased compared to the viewing angle of the visible light imaging element 7, and unused pixels 9p are generated in the effective pixel area 9a2 of the fluorescent imaging element 9.

[0086] When the ratio (D2 / D1) is less than 1, the fluorescence imaging element 9 is relatively small relative to the prism 6, and there is space for the optical path. Unnecessary light generated by reflection from the components constituting the prism 6 and input into the fluorescence imaging element 9 can be reduced, and weak fluorescence FL can be clearly captured. For example, unnecessary light components (such as halos that appear as the sensitivity of the fluorescence imaging element 9 increases) are reduced, and a clear fluorescence image can be obtained. When the ratio (D2 / D1) is greater than 1, the pixel size W2 can be increased while maintaining a relatively large number of pixels 9p, and weak fluorescence FL can be captured with high sensitivity and high resolution. When the ratio (D2 / D1) is 1, increasing the pixel pitch P2 in the fluorescence imaging element 9 makes it possible to increase the pixel size W2 for high sensitivity, and further, make the accompanying components common to facilitate the assemblability of the imaging device 1.

[0087] Note that the lower limit value of the ratio (D2 / D1) may be greater than the value expressed in the above conditional expression (2). Examples of such a lower limit value are 0.8, 0.9, 1.0, etc. Note that the upper limit value thereof may be less than the value expressed in the conditional expression (2). Examples of such an upper limit value are 1.3, 1.2, 1.1, etc.

[0088] <Design conditions 1-3>

[0089] According to the characteristics of the optical diagnosis component 3 and the imaging lens 4, the wavelengths of the respective lights, etc., the optical path lengths of the visible light VL and the fluorescent light FL input into the prism 6 to the imaging may be different from each other. In this case, the visible light imaging element 7 may be located at the imaging position of the visible light VL and the fluorescent light imaging element 9 may be located at the imaging position of the fluorescent light FL to suppress the influence of the difference between the optical path lengths (optical path length difference), that is, to absorb the deviation amount of the optical path length difference. This configuration only requires the focusing of the visible light imaging element 7 to focus the fluorescent light imaging element 9, and facilitates the capture of the visible light VL with high resolution and the clear capture of the fluorescent light FL. Several embodiments of the specific positioning method will be described.

[0090] <Positioning method 1-1>

[0091] In one embodiment, the long pass filter 8 may have an optical axis length designed according to the above optical path length difference to position the fluorescence imaging element 9 at the imaging position of the fluorescence FL. When the input surface 8a of the long pass filter 8 is perpendicular to the optical axis, the optical axis length of the long pass filter 8 corresponds to the thickness of the long pass filter 8. Adjusting the thickness of the long pass filter 8 makes it possible to bring the fluorescence imaging element 9 closer to or farther away from the prism 6.

[0092] <Positioning method 1-2>

[0093] In one embodiment, the prism 6 may have an optical axis length designed according to the above optical path length difference to position the visible light imaging element 7 at the imaging position of the visible light VL and the fluorescent imaging element 9 at the imaging position of the fluorescent light FL. For example, the optical axis length of the adjustment block 61 makes it possible to bring the visible light imaging element 7 closer to or farther from the prism 6. The optical axis length of the adjustment block 62 makes it possible to bring the fluorescent imaging element 9 closer to or farther from the prism 6.

[0094] <Positioning Method 1-3>

[0095] In one embodiment, the imaging device 1 may include a gap portion positioned between the prism 6 and at least one of the visible light imaging element 7 and the fluorescent imaging element 9. The gap portion may have an optical axis length designed according to the above-mentioned optical path length difference to position the visible light imaging element 7 at the imaging position of the visible light VL and the fluorescent imaging element 9 at the imaging position of the fluorescent light FL. A retaining member for setting the gap portion configured as described above may be used. Fig.10 Give a description.

[0096] Fig.10 1 is a diagram showing an embodiment of a holding member. In this embodiment, the holding member 10 is provided to be positioned in the gap portion G between the block 62 of the prism 6 and the fluorescent imaging element 9. Note that the long pass filter 8 ( Figure 1 ). The gap portion G may also be referred to as an air gap between the block 62 and the fluorescent imaging element 9. The holding member 10 holds the fluorescent imaging element 9 to set the gap portion G. Specifically, in this embodiment, the holding member 10 includes a substrate 101 and a holding rod 102.

[0097] The substrate 101 is bonded to the light receiving surface 9a of the fluorescent imaging element 9 to support the fluorescent imaging element 9. An example of the material of the substrate 101 is glass or the like, and the fluorescent light FL transmitted by the substrate 101 is input into the light receiving surface 9a of the fluorescent imaging element 9. The holding rod 102 includes one end 102a connected to the edge of the substrate 101 and the other end 102b of the side surface of the block 62 holding the prism 6. The holding rod 102 has a length that gives the optical axis length of the gap portion G. Adjusting the length of the holding rod 102 makes it possible to bring the fluorescent imaging element 9 closer to or farther from the prism 6.

[0098] Note that the imaging device 1 may include the holding member 10 that holds the visible light imaging element 7 instead of or in addition to the fluorescent imaging element 9 that holds the holding member 10 .

[0099] 2. Second Implementation

[0100] Fig.11 is a diagram showing an example of a schematic configuration of an imaging device according to the second embodiment. Fig.11 The above-described Figure 1 The embodiment of the present invention is an observation object S, a light source 2, an optical diagnosis component 3, and an imaging lens 4. The differences from the first embodiment will be mainly described. The prism 6 also includes a dichroic film 66. The block 62 of the prism 6 includes a block 621 and a block 622. The long pass filter 8 includes a long pass filter 81 and a long pass filter 82. The fluorescence imaging element 9 includes a fluorescence imaging element 91 and a fluorescence imaging element 92.

[0101] The fluorescence FL included in the light L input to the prism 6 includes fluorescence FL1 and fluorescence FL2. The fluorescence FL1 and the fluorescence FL2 are first fluorescence and second fluorescence belonging to different wavelength bands. For example, the fluorescence FL1 is near-infrared light, and the fluorescence FL2 is light on the longer wavelength side than the near-infrared light. Note that the excitation light source 22 ( Figure 1 ) can output two kinds of excitation light that excite the observation object S, so that the reagent injected into the observation object S emits fluorescence FL1 and fluorescence FL2. For example, two reagents, that is, a reagent that emits fluorescence FL1 and a reagent that emits fluorescence FL2, are injected into the observation object S.

[0102] The prism 6 separates and outputs the visible light VL, the fluorescence FL1 and the fluorescence FL2. The block 621 is positioned between the block 61 and the block 622. The surface of the prism 6 from which the fluorescence FL1 is output is referred to as the output surface 6b21 in the figure. The surface from which the fluorescence FL2 is output is referred to as the output surface 6b22 in the figure. The output surface 6b21 is part of the surface of the block 621. The output surface 6b22 is part of the surface of the block 622.

[0103] The dichroic film 66 is disposed between the block 621 and the block 622 so that the fluorescent light FL1 and the fluorescent light FL2 transmitted by the dichroic film 65 are input. In this embodiment, the dichroic film 66 is formed in the block 621. The dichroic film 66 reflects the fluorescent light FL1 and transmits the fluorescent light FL2. Fig.12 Give a description.

[0104] Fig.12 : is a graph showing an example of the characteristics of the dichroic film 66. The reflectance is high in a wavelength band including at least the fluorescence FL1, and the transmittance is high in a wavelength band including at least the fluorescence FL2.

[0105] return Fig.11 , the block 621 outputs the fluorescence FL1 reflected by the dichroic film 66 from the output surface 6b21. The block 622 outputs the fluorescence FL2 transmitted by the dichroic film 66 from the output surface 6b22.

[0106] The long-pass filter 81 is disposed between the block 621 and the fluorescence imaging element 91. The long-pass filter 81 transmits the fluorescence FL1, and reflects or attenuates light having a wavelength shorter than that of the fluorescence FL1. The long-pass filter 82 is disposed between the block 622 and the fluorescence imaging element 92. The long-pass filter 82 transmits the fluorescence FL2, and reflects or attenuates light having a wavelength shorter than that of the fluorescence FL2.

[0107] Fluorescence FL1 from long pass filter 81 is imaged and captured by fluorescence imaging element 91. Fluorescence imaging element 91 may be a first fluorescence imaging element designed to capture fluorescence FL1 with high sensitivity. Fluorescence imaging element 91 is directly or indirectly fixed to prism 6 to be located at the imaging position of fluorescence FL1.

[0108] The fluorescence FL2 from the long pass filter 82 is imaged and captured by the fluorescence imaging element 92. The fluorescence imaging element 92 may be a second fluorescence imaging element designed to capture the fluorescence FL2 with high sensitivity. The fluorescence imaging element 92 is directly or indirectly fixed to the prism 6 to be located at the imaging position of the fluorescence FL2.

[0109] In the second embodiment, the pixel pitch and the effective pixel area diagonal length of the visible light imaging element 7 are respectively referred to as the pixel pitch P3 and the effective pixel area diagonal length D3. The pixel pitch and the effective pixel area diagonal length of the fluorescent imaging element 91 are respectively referred to as the pixel pitch P4 and the effective pixel area diagonal length D4. The pixel pitch and the effective pixel area diagonal length of the fluorescent imaging element 92 are respectively referred to as the pixel pitch P5 and the effective pixel area diagonal length D5.

[0110] The imaging device 1 according to the second embodiment is designed to capture visible light VL with high resolution and clearly capture fluorescence FL1 and fluorescence FL2. Several design conditions will be described. Note that among the design conditions described below, non-exclusive design conditions can be appropriately combined.

[0111] <Design Condition 2-1>

[0112] In one embodiment, the ratio of the pixel pitch P4 in the fluorescent imaging element 91 to the pixel pitch P3 in the visible light imaging element 7 (P4 / P3) and the ratio of the pixel pitch P5 in the fluorescent imaging element 92 to the pixel pitch P3 in the visible light imaging element 7 (P5 / P3) can both be greater than 1 and less than 5. In other words, the pixel pitch P3 in the visible light imaging element 7, the pixel pitch P4 in the fluorescent imaging element 91, and the pixel pitch P5 in the fluorescent imaging element 92 can be designed to satisfy the following conditional expression (3). The technical significance is similar to that of the conditional expression (1) described in the above-mentioned first embodiment, and its description will not be repeated. The same applies to the point where the lower limit value can be greater than the value represented by the conditional expression and the point where the upper limit value can be less than the value represented by the conditional expression.

[0113] and

[0114] <Design Condition 2-2>

[0115] In one embodiment, the ratio (D4 / D3) of the effective pixel area diagonal length D4 of the fluorescent imaging element 91 to the effective pixel area diagonal length D3 of the visible light imaging element 7 and the ratio (D5 / D3) of the effective pixel area diagonal length D5 of the fluorescent imaging element 92 to the effective pixel area diagonal length D3 of the visible light imaging element 7 can both be greater than 0.7 and less than 1.4. In other words, the effective pixel area diagonal length D3 of the visible light imaging element 7, the effective pixel area diagonal length D4 of the fluorescent imaging element 91, and the effective pixel area diagonal length D5 of the fluorescent imaging element 92 can be designed to satisfy the following conditional expression (4). The technical significance is similar to that of the conditional expression (2) described in the first embodiment above, and its description will not be repeated. The same applies to points where the lower limit value can be greater than the value represented by the conditional expression and points where the upper limit value can be less than the value represented by the conditional expression.

[0116] and

[0117] <Design Conditions 2-3>

[0118] According to the characteristics of the optical diagnosis component 3 and the imaging lens 4, the wavelengths of the respective lights, etc., the optical path lengths of the visible light VL, the fluorescence FL1, and the fluorescence FL2 input into the prism 6 to the imaging may be different from each other. In this case, the visible light imaging element 7 may be located at the imaging position of the visible light VL, the fluorescence imaging element 91 may be located at the imaging position of the fluorescence FL1, and the fluorescence imaging element 92 may be located at the imaging position of the fluorescence FL2 to suppress the influence of the optical path length difference. This configuration requires only the focusing of the visible light imaging element 7 to focus the fluorescence imaging element 91 and the fluorescence imaging element 92, and facilitates the capture of the visible light VL with high resolution and the clear capture of the fluorescence FL1 and the fluorescence FL2. Several embodiments of the specific positioning method will be described.

[0119] <Positioning method 2-1>

[0120] In one embodiment, the long-pass filter 81 may have an optical axis length designed according to, for example, the optical path length difference between the visible light VL and the fluorescent light FL1, so as to position the fluorescent imaging element 91 at the imaging position of the fluorescent light FL1. Similarly, the long-pass filter 82 may have an optical axis length designed according to, for example, the optical path length difference between the visible light VL and the fluorescent light FL2, so as to position the fluorescent imaging element 92 at the imaging position of the fluorescent light FL2.

[0121] <Positioning method 2-2>

[0122] In one embodiment, the prism 6 may have an optical axis length designed according to the above optical path length difference to position the visible light imaging element 7 at the imaging position of the visible light VL, the fluorescent imaging element 91 at the imaging position of the fluorescent light FL1, and the fluorescent imaging element 92 at the coupling position of the fluorescent light FL2. For example, the optical axis length of the adjustment block 61 makes it possible to bring the visible light imaging element 7 closer to or farther from the prism 6. The optical axis length of the adjustment block 621 makes it possible to bring the fluorescent imaging element 91 closer to or farther from the prism 6. The optical axis length of the adjustment block 622 makes it possible to bring the fluorescent imaging element 92 closer to or farther from the prism 6.

[0123] <Positioning method 2-3>

[0124] In one embodiment, the imaging device 1 may include a gap portion positioned between the prism 6 and at least one of the visible light imaging element 7, the fluorescent imaging element 91, and the fluorescent imaging element 92. The gap portion may have an optical axis length designed according to the above-mentioned optical path length difference to position the visible light imaging element 7 at the imaging position of the visible light VL, the fluorescent imaging element 91 at the imaging position of the fluorescent light FL1, and the fluorescent imaging element 92 at the imaging position of the fluorescent light FL2. A retaining member for setting the gap portion configured as described above may be used. The gap portion and the retaining member may have the same optical axis length as the reference image. Fig.10 The clearance portion and the holding member described in the first embodiment are similarly configured.

[0125] 3. Third Implementation

[0126] Fig.13 is a diagram showing an example of a schematic configuration of an imaging device according to a third embodiment. Fig.13 The above-described Figure 1 The prism 6 does not include a dichroic film 65 ( Figure 1 ), but includes a dichroic film 67, a dichroic film 68 and a dichroic film 69. The block 61 of the prism 6 includes a block 611, a block 612 and a block 613. The blocks 611 and 612 can be arranged so that air is interposed therebetween. Similarly, the blocks 612 and 613 can be arranged so that air is interposed therebetween. The visible light imaging element 7 includes a green light imaging element 7G, a blue light imaging element 7B and a red light imaging element 7R. The long pass filter 8 includes a long pass filter 8IR. The fluorescent imaging element 9 includes an infrared imaging element 9IR.

[0127] Visible light VL included in the light L input to the prism 6 includes green light VLG, blue light VLB, and red light VLR. Fluorescent light FL includes infrared light FLIR.

[0128] The prism 6 separates and outputs green light VLG, blue light VLB, red light VLR, and infrared light FLIR. Blocks 612, 613, and block 62 are positioned successively relative to block 61. Block 613 is positioned between block 612 and block 62. The surface of the prism 6 from which the green light VLG is output is referred to as output surface 6bG in the figure. The surface from which the blue light VLB is output is referred to as output surface 6bB in the figure. The surface from which the red light VLR is output is referred to as output surface 6bR in the figure. The surface from which the infrared light FLIR is output is referred to as output surface 6bIR in the figure. Output surface 6bG is part of the surface of block 611. Output surface 6bB is part of the surface of block 612. Output surface 6bR is part of the surface of block 613. Output surface 6bIR is part of the surface of block 62.

[0129] The dichroic film 67 is disposed between the block 611 and the block 612 so that the light L from the input surface 6a of the prism 6 is input. In this embodiment, the dichroic film 67 is formed in the block 611. The dichroic film 67 reflects the green light VLG and transmits other light. Fig.14 Give a description.

[0130] Fig.14 : is a diagram showing an example of the characteristics of the dichroic film 67. The reflectance is high in the wavelength band of green light VLG, and the transmittance is high in other wavelength bands.

[0131] return Fig.13 , the dichroic film 68 is disposed between the block 612 and the block 613. In this embodiment, the dichroic film 68 is formed in the block 612. The dichroic film 68 reflects the blue light VLB and transmits other light. Fig.15 Give a description.

[0132] Fig.15 : is a diagram showing an example of the characteristics of the dichroic film 68. The reflectance is high in the wavelength band of blue light VLB, and the transmittance is high in other wavelength bands.

[0133] return Fig.13 , the dichroic film 69 is disposed between the block 613 and the block 62. In this embodiment, the dichroic film 69 is formed in the block 613. The dichroic film 69 reflects the red light VLR and transmits the infrared light FLIR. Fig.16 Give a description.

[0134] Fig.16 : is a diagram showing an example of the characteristics of the dichroic film 69. The reflectivity is high in the wavelength band of the red light VLR, and the transmittance is high in the wavelength band of the infrared light FLIR.

[0135] return Fig.13, block 611 outputs green light VLG reflected by the dichroic film 67 from the output surface 6bG. Block 612 outputs blue light VLB transmitted by the dichroic film 67 and reflected by the dichroic film 68 from the output surface 6bB. Block 613 outputs red light VLR transmitted by the dichroic film 68 and reflected by the dichroic film 69 from the output surface 6bR. Block 62 outputs light (including light of infrared light FLIR) transmitted by the dichroic film 69 from the output surface 6bIR.

[0136] The green light VLG output from the output surface 6bG of the prism 6 is imaged and captured by the green light imaging element 7G. The green light imaging element 7G may be a visible light imaging element designed to capture the green light VLG with high sensitivity and high resolution. For example, each of the pixels included in the green light imaging element 7G is configured to receive green light. The green light imaging element 7G is directly or indirectly fixed to the prism 6 to be located at the imaging position of the green light VLG.

[0137] The blue light VLB output from the output surface 6bB of the prism 6 is imaged and captured by the blue light imaging element 7B. The blue light imaging element 7B may be a visible light imaging element designed to capture the blue light VLB with high sensitivity and high resolution. For example, each of the pixels included in the blue light imaging element 7B is configured to receive blue light. The blue light imaging element 7B is directly or indirectly fixed to the prism 6 to be located at the imaging position of the blue light VLB.

[0138] The red light VLR output from the output surface 6bR of the prism 6 is imaged and captured by the red light imaging element 7R. The red light imaging element 7R may be a visible light imaging element designed to capture the red light VLR with high sensitivity and high resolution. For example, each of the pixels included in the red light imaging element 7R is configured to receive red light. The red light imaging element 7R is directly or indirectly fixed to the prism 6 to be located at the imaging position of the red light VLR.

[0139] Long pass filter 8IR is provided between block 62 and infrared imaging element 9IR. Long pass filter 8IR transmits infrared light FLIR, and reflects or attenuates light having a wavelength shorter than that of infrared light FLIR.

[0140] The infrared light FLIR from the output surface 6bIR of the prism 6, more specifically, in this embodiment, the infrared light FLIR from the long pass filter 8IR is imaged and captured by the infrared imaging element 9IR. The infrared imaging element 9IR may be an infrared imaging element designed to capture the infrared light FLIR from the long pass filter 8IR with high sensitivity. The infrared imaging element 9IR is directly or indirectly fixed to the prism 6 to be located at the imaging position of the infrared light FLIR.

[0141] In the third embodiment, the pixel pitch and the effective pixel area diagonal length of the green light imaging element 7G are respectively referred to as the pixel pitch P6 and the effective pixel area diagonal length D6. The pixel pitch and the effective pixel area diagonal length of the infrared imaging element 9IR are respectively referred to as the pixel pitch P7 and the effective pixel area diagonal length D7. Note that the pixel pitch and the effective pixel area diagonal length of the blue light imaging element 7B and the red light imaging element 7R may be the same as the pixel pitch P6 and the effective pixel area diagonal length D6 of the green light imaging element 7G, for example.

[0142] The imaging device 1 according to the third embodiment is designed to capture green light VLG, blue light VLB, and red light VLR with high resolution and clearly capture infrared light FLIR. Several design conditions will be described. Note that among the design conditions described below, non-exclusive design conditions can be appropriately combined.

[0143] <Design Condition 3-1>

[0144] In one embodiment, the ratio (P7 / P6) of the pixel pitch P7 in the infrared imaging element 9IR to the pixel pitch P6 in the green light imaging element 7G can be greater than 1 and less than 5. In other words, the pixel pitch P6 in the green light imaging element 7G and the pixel pitch P7 in the infrared imaging element 9IR can be designed to satisfy the following conditional expression (5). The technical significance is similar to that of the conditional expression (1) described in the first embodiment above, and its description will not be repeated. The same applies to the point where the lower limit value can be greater than the value represented by the conditional expression and the point where the upper limit value can be less than the value represented by the conditional expression.

[0145]

[0146] <Design Condition 3-2>

[0147] In one embodiment, the ratio (D7 / D6) of the effective pixel area diagonal length D7 of the infrared imaging element 9IR to the effective pixel area diagonal length D6 of the green light imaging element 7G can be greater than 0.7 and less than 1.4. In other words, the effective pixel area diagonal length D6 of the green light imaging element 7G and the effective pixel area diagonal length D7 of the infrared imaging element 9IR can be designed to satisfy the following conditional expression (6). The technical significance is similar to that of the conditional expression (2) described in the first embodiment above, and its description will not be repeated. The same applies to points where the lower limit value can be greater than the value represented by the conditional expression and points where the upper limit value can be less than the value represented by the conditional expression.

[0148]

[0149] <Design Condition 3-3>

[0150] According to the characteristics of the imaging lens 4, the wavelengths of each light, etc., the optical path lengths of the green light VLG and the infrared light FLIR input into the prism 6 to the imaging may be different from each other. The green light imaging element 7G may be located at the imaging position of the green light VLG, and the infrared imaging element 9IR may be located at the imaging position of the infrared light FLIR to suppress the influence of the optical path length difference. This configuration only requires the green light imaging element 7G to focus in order to focus the infrared imaging element 9IR, and facilitates capturing the green light VLG (further, the blue light VLB, the red light VLR) with high resolution and clearly capturing the infrared light FLIR. Several embodiments of the specific positioning method will be described.

[0151] <Positioning method 3-1>

[0152] In one embodiment, the long pass filter 8IR may have an optical axis length designed according to the optical path length difference between the green light VLG and the infrared light FLIR, so as to position the infrared imaging element 9IR at the imaging position of the infrared light FLIR.

[0153] <Positioning method 3-2>

[0154] In one embodiment, the prism 6 may have an optical axis length designed according to the above optical path length difference to position the green light imaging element 7G at the imaging position of the green light VLG and the infrared imaging element 9IR at the imaging position of the infrared light FLIR. For example, the optical axis length of the adjustment block 611 allows the green light imaging element 7G to be closer to or farther from the prism 6. The optical axis length of the adjustment block 62 allows the infrared imaging element 9IR to be closer to or farther from the prism 6.

[0155] <Positioning method 3-3>

[0156] In one embodiment, the imaging device 1 may include a gap portion positioned between the prism 6 and at least one of the green light imaging element 7G and the infrared imaging element 9IR. The gap portion may have an optical axis length designed according to the above-mentioned optical path length difference to position the green light imaging element 7G at the imaging position of the green light VLG and the infrared imaging element 9IR at the imaging position of the infrared light FLIR. A retaining member for setting the gap portion configured as described above may be used. The gap portion and the retaining member may have the same optical axis length as the reference. Fig.10 The gap portion and the holding member described in the first embodiment are similarly configured.

[0157] 4. Modifications

[0158] The disclosed technology is not limited to the above-described embodiments. Several embodiments will be described.

[0159] The positions of the imaging elements can be appropriately interchanged. For example, in the first embodiment, the positions of the visible light imaging element 7 and the fluorescent imaging element 9 can be interchanged. The characteristics of the dichroic film 65 of the prism 6, the arrangement of the long pass filter 8, etc. can also be changed according to the interchange. In the second embodiment, the positions of the visible light imaging element 7 and the fluorescent imaging element 9 can also be interchanged. In addition, the positions of the fluorescent imaging element 91 and the fluorescent imaging element 92 can be interchanged. The characteristics of the dichroic film 66 of the prism 6, the arrangement of the long pass filter 81 and the long pass filter 82, etc. can also be changed according to the interchange. In the third embodiment, the positions of the visible light imaging element 7 and the fluorescent imaging element 9 can also be interchanged. In addition, the positions of the green light imaging element 7G, the blue light imaging element 7B and the red light imaging element 7R can be interchanged. The characteristics of the dichroic film 67, the dichroic film 68 and the dichroic film 69 of the prism 6, the arrangement of the long pass filter 8IR, etc. can be changed according to the interchange.

[0160] As described in part above, a gap (e.g., an air gap) may exist between the prism 6 and the visible light imaging element 7, between the prism 6 and the long pass filter 8, or between the long pass filter 8 and the visible light imaging element 7. In addition, the excitation light cutoff filter 5 may also be bonded to the block 61 of the prism 6. An air gap may exist between the blocks included in the prism 6.

[0161] 5. Application examples

[0162] The technology according to the present disclosure can be applied to a medical imaging system. A medical imaging system is a medical system that uses imaging technology, and is, for example, a medical observation system such as an endoscope system or a microscope system.

[0163] <Endoscope System>

[0164] Will use Fig.17 , Fig.18 Embodiments of endoscopy systems are described. Fig.17 is a diagram showing an example of a schematic configuration of an endoscope system 5000 to which the technology according to the present disclosure can be applied. Fig.18 is a diagram showing an example of the configuration of an endoscope 5001 and a camera control unit (CCU) 5039. Fig.17 FIG. 5 shows a situation in which an operator (eg, a doctor) 5067 as an operation participant uses an endoscope system 5000 to operate a patient 5071 on a bed 5069. Fig.17 As shown, the endoscope system 5000 includes an endoscope 5001 as a medical imaging device, a CCU 5039, a light source device 5043, a recording device 5053, an output device 5055, and a supporting device 5027 for supporting the endoscope 5001.

[0165] In endoscopic surgery, an insertion aid tool called a trocar 5025 is inserted into a patient 5071. Then, a viewer 5003 connected to the endoscope 5001 and surgical tools 5021 are inserted into the body of the patient 5071 through the trocar 5025. The surgical tools 5021 include, for example: an energy device such as an electric scalpel; and forceps.

[0166] A surgical image in which the inside of a patient 5071 body is captured through an endoscope 5001 is displayed on a display device 5041. An operator 5067 performs a surgical procedure on a surgical object using a surgical tool 5021 while viewing the surgical image displayed on the display device 5041. The medical image is not limited to a surgical image, and may be a diagnostic image captured during diagnosis.

[0167] <Endoscope>

[0168] The endoscope 5001 is an imaging part for capturing the inside of the body of the patient 5071, and for example Fig.18As shown, it is a camera head, which includes a converging optical system 50051 for converging incident light, a zoom optical system 50052 capable of optical zooming by changing the focal length of the imaging part, a focusing optical system 50053 capable of optical focusing by changing the focal length of the imaging part, and a light receiving element 50054. The endoscope 5001 converges the light passing through the connected observer 5003 onto the light receiving element 50054 to generate a pixel signal, and outputs the pixel signal to the CCU 5039 through the transmission system. The observer 5003 is an insertion part including an objective lens at the front end, and guides the light from the connected light source device 5043 into the body of the patient 5071. The observer 5003 is, for example, a rigid observer for a rigid endoscope and a flexible observer for a flexible endoscope. The observer 5003 can be a straight-view observer or an oblique-view observer. The pixel signal only needs to be a signal based on a signal output from a pixel, and is, for example, a raw signal or an image signal. The transmission system that connects the endoscope 5001 to the CCU 5039 may include a memory, and the memory may store parameters related to the endoscope 5001 and the CCU 5039. The memory may be arranged at the connection part of the transmission system or on the cable. For example, the memory of the transmission system may store parameters before the endoscope 5001 leaves the factory or parameters that change when current is applied, and the operation of the endoscope may be changed based on the parameters read from the memory. The set of the camera head and the transmission system may be referred to as an endoscope. The light receiving element 50054 is a sensor for converting the received light into a pixel signal, and is, for example, a complementary metal oxide semiconductor (CMOS) imaging element. The light receiving element 50054 is preferably an imaging element having a Bayer array capable of color imaging. The light receiving element 50054 is also preferably an imaging element having a plurality of pixels corresponding to a resolution of, for example, 4K (3840 horizontal pixels × 2160 vertical pixels), 8K (7680 horizontal pixels × 4320 vertical pixels), or square 4K (3840 or more horizontal pixels × 3840 or more vertical pixels). The light receiving element 50054 may be a sensor chip or a plurality of sensor chips. For example, a prism may be provided to separate incident light into predetermined wavelength bands, and the wavelength bands may be imaged by different light receiving elements. A plurality of light receiving elements may be provided for stereoscopic viewing. The light receiving element 50054 may be a sensor having a chip structure including an arithmetic processing circuit for image processing, or may be a sensor for time of flight (ToF). The transmission system is, for example, an optical fiber cable system or a wireless transmission system. Wireless transmission only needs to be able to transmit the pixel signal generated by the endoscope 5001, and for example, the endoscope 5001 can be wirelessly connected to the CCU 5039, or the endoscope 5001 can be connected to the CCU 5039 via a base station in the operating room.At this time, the endoscope 5001 can not only transmit pixel signals, but also simultaneously transmit information related to the pixel signals (e.g., processing priority of the pixel signals and / or synchronization signals). In the endoscope, the viewer can be integrated with the camera, and the light receiving element can be provided at the front end of the viewer.

[0169] <Camera Control Unit (CCU)>

[0170] The CCU 5039 is a control device for controlling the endoscope 5001 and the light source device 5043 connected to the CCU 5039 in an integrated manner, and is, for example, Fig.18 As shown, it is an image processing device including a field programmable gate array (FPGA) 50391, a central processing unit (CPU) 50392, a random access memory 50393, a read-only memory (ROM) 50394, a graphics processing unit (GPU) 50395, and an interface (I / F) 50396. The CCU 5039 can control a display device 5041, a recording device 5053, and an output device 5055 connected to the CCU 5039 in an integrated manner. The CCU 5039 controls, for example, the irradiation timing, irradiation intensity, and type of irradiation light source of the light source device 5043. The CCU 5039 also performs image processing such as development processing (e.g., demosaic processing) and correction processing on the pixel signal output from the endoscope 5001, and outputs the processed image signal (e.g., image) to an external device such as the display device 5041. The CCU 5039 also transmits a control signal to the endoscope 5001 to control the driving of the endoscope 5001. The control signal is information about imaging conditions such as the magnification or focal length of the imaging portion. The CCU 5039 may have a function of down-converting an image, and may be configured to be able to simultaneously output a higher resolution (e.g., 4K) image to the display device 5041 and a lower resolution (e.g., high definition (HD)) image to the recording device 5053.

[0171] The CCU 5039 can be connected to an external device (such as a recording device, a display device, an output device, and a supporting device) via an IP converter for converting a signal into a predetermined communication protocol (such as an Internet Protocol (IP)). The connection between the IP converter and the external device can be established using a wired network, or part or all of the network can be established using a wireless network. For example, the IP converter on the CCU 5039 side can have a wireless communication function, and the received image can be transmitted to the IP switch or the output side IP converter via a wireless communication network such as a fifth generation mobile communication system (5G) or a sixth generation mobile communication system (6G).

[0172] <Light source device>

[0173] The light source device 5043 is a device capable of emitting light having a predetermined wavelength band, and includes, for example, a plurality of light sources and a light source optical system for guiding the light of the light source. The light source is, for example, a xenon lamp, a light emitting diode (LED) light source, or a laser diode (LD) light source. The light source device 5043 includes, for example, LED light sources corresponding to the three primary colors of red (R), green (G), and blue (B), and controls the output intensity and output timing of each of the light sources to emit white light. In addition to the light source for emitting ordinary light for ordinary light observation, the light source device 5043 may also include a light source capable of emitting special light for special light observation. Special light is light having a predetermined wavelength band different from ordinary light as light for ordinary light observation, and is, for example, near infrared light (light with a wavelength of 760nm or more), infrared light, blue light, or ultraviolet light. Ordinary light is, for example, white light or green light. In narrow-band imaging as a special light observation, blue light and green light are emitted alternately, and thus narrow-band imaging can utilize the wavelength dependence of light absorption in body tissue to image predetermined tissues such as blood vessels on the mucosal surface with high contrast. In fluorescence observation as a special light observation, excitation light is emitted to excite the reagent injected into the body tissue, and fluorescence emitted by the body tissue or the drug as a label is received to obtain a fluorescence image, and therefore, fluorescence observation can facilitate the operator to view body tissues that are difficult for the operator to view using ordinary light, for example. For example, in fluorescence observation using infrared light, infrared light with an excitation wavelength band is emitted to a reagent such as indocyanine green (ICG) injected into the body tissue, and fluorescence from the reagent is received, whereby fluorescence observation can facilitate viewing of the structure and affected part of the body tissue. In fluorescence observation, a reagent (such as 5-aminolevulinic acid (5-ALA)) that emits fluorescence in the red wavelength band by being excited by special light in the blue wavelength band can be used. The type of irradiation light of the light source device 5043 is set by the control of the CCU 5039. The CCU 5039 may have a mode for controlling the light source device 5043 and the endoscope 5001 to alternately perform ordinary light observation and special light observation. At this time, it is preferred that information based on pixel signals obtained by special light observation is superimposed on pixel signals obtained by ordinary light observation. Special light observation can be infrared light observation for observing the internal part of the organ surface and multi-spectral observation using hyperspectral spectroscopy. Photodynamic therapy can be combined.

[0174] <Recording Device>

[0175] The recording device 5053 is a device for recording a pixel signal (e.g., an image) acquired from the CCU 5039, and is, for example, a recorder. The recording device 5053 records the image acquired from the CCU 5039 in a hard disk drive (HDD), an ultra-dense disk (SDD), and / or an optical disk. The recording device 5053 may be connected to a network in the hospital to be accessible from a device outside the operating room. The recording device 5053 may have a down-conversion function or an up-conversion function.

[0176] <Display device>

[0177] The display device 5041 is a device capable of displaying an image, and is, for example, a display monitor. The display device 5041 displays a display image based on a pixel signal acquired from the CCU 5039. The display device 5041 may include a camera and a microphone to serve as an input device that allows command input through gaze recognition, voice recognition, and gestures.

[0178] <Output device>

[0179] The output device 5055 is a device for outputting information acquired from the CCU 5039 and is, for example, a printer. For example, the output device 5055 prints a print image on paper based on a pixel signal acquired from the CCU 5039.

[0180] <Supporting device>

[0181] The support device 5027 is an articulated arm including a base 5029 (the base includes an arm control device 5045), an arm 5031 extending from the base 5029, and a holding portion 5032 installed at the front end of the arm 5031. The arm control device 5045 includes a processor such as a CPU, and operates according to a predetermined computer program to control the drive of the arm 5031. The support device 5027 uses the arm control device 5045 to control parameters such as the length of the link 5035 constituting the arm 5031, the rotation angle and torque of the joint 5033 to control, for example, the position and posture of the endoscope 5001 held by the holding portion 5032. This control can change the position or posture of the endoscope 5001 to a desired position or posture, so that the viewer 5003 can be inserted into the patient 5071, and the observation area in the body can be changed. The support device 5027 serves as an endoscope support arm for supporting the endoscope 5001 during operation. Therefore, the support device 5027 can play a role as an auxiliary observer holding the endoscope 5001. The support device 5027 may be a device for holding the microscope device 5301 to be described later, and may be referred to as a medical support arm. The support device 5027 may be controlled by the arm control device 5045 using an autonomous control method, or may be controlled using a control method in which the arm control device 5045 performs control based on a user's input. The control method may be, for example, a master-slave method in which the support device 5027 serving as a slave device (replica device) as a patient cart is controlled based on the movement of a master device (base device) as an operator console on the user's hand. The support device 5027 may be capable of remote control from outside the operating room.

[0182] An embodiment of the endoscope system 5000 to which the technology according to the present disclosure is applicable has been described above. For example, the technology according to the present disclosure may be applied to a microscope system.

[0183] <Microscope system>

[0184] Fig.19 5000 is a diagram showing an example of a schematic configuration of a microscope surgery system to which the technology according to the present disclosure is applicable. In the following description, the same components as those of the endoscope system 5000 will be denoted by the same reference numerals, and description thereof will not be repeated.

[0185] Fig.19 The schematic diagram shows a situation where an operator 5067 uses a microscope surgery system 5300 to operate on a patient 5071 on a bed 5069. For simplicity, Fig.19The cart 5037 is not shown among the components of the microscope surgery system 5300, and the microscope device 5301 is shown in a simplified manner instead of the endoscope 5001. The microscope device 5301 may refer to a microscope 5303 provided at the front end of the connecting rod 5035, or may refer to an overall configuration including the microscope 5303 and the support device 5027.

[0186] like Fig.19 As shown in , during operation, a microscope surgery system 5300 is used to display an image of a surgical site captured by a microscope device 5301 in an enlarged manner on a display device 5041 installed in an operating room. The display device 5041 is installed in a position facing an operator 5067, and the operator 5067 performs various surgical procedures such as resection of an affected part on the surgical site while observing the state of the surgical site using the image displayed on the display device 5041. The microscope surgery system is used for, for example, ophthalmic surgery and neurosurgery.

[0187] The corresponding embodiments of the endoscope system 5000 and the microscope surgical system 5300 applicable according to the technology of the present disclosure have been described above. The system applicable according to the technology of the present disclosure is not limited to such an embodiment. For example, instead of the endoscope 5001 or the microscope 5303, the support device 5027 can support another observation device or another surgical tool at its front end. Embodiments of other applicable observation devices include forceps, tweezers, pneumoperitoneum tubes for pneumoperitoneum, energy treatment tools for cutting tissue or sealing blood vessels by cauterization, etc. By using a support device to support the above-mentioned observation device or surgical tool, its position can be fixed more stably and the load on the medical staff can be reduced compared to the case where the medical staff manually supports the observation device or surgical tool. The technology according to the present disclosure can be applied to a support device that supports such components other than a microscope.

[0188] The imaging device 1 according to each embodiment described above can be suitably applied to the endoscope 5001 and the microscope device 5301 of the above configuration. Specifically, the observation target S is a surgical site. The light source 2 can constitute the light source device 5043. The optical diagnostic component 3 can partially constitute the endoscope 5001 or the microscope device 5301. The imaging lens 4, the excitation light cutoff filter 5, the prism 6, the visible light imaging element 7, the long pass filter 8, the fluorescence imaging element 9, etc. can be used as an imaging unit. The use of the imaging device 1 makes it possible to capture visible light (ordinary light) with high resolution and to clearly capture fluorescence (special light).

[0189] 6. Effect examples

[0190] For example, the above technology is defined as follows. One aspect of the disclosed technology is an imaging device 1. As shown in FIG. Figures 1 to 9As described in FIG. 1 , the imaging device 1 includes a prism 6 (which separates visible light VL and fluorescence FL included in light L from an observation object S), a visible light imaging element 7 (which captures the visible light VL separated by the prism 6), and a fluorescence imaging element 9 (which captures the fluorescence FL separated by the prism 6). The ratio of the pixel pitch P2 in the fluorescence imaging element 9 to the pixel pitch P1 in the visible light imaging element 7 is greater than 1 and less than 5 (1≤(P2 / P1)<5). Designing the pixel pitch P1 in the visible light imaging element 7 and the pixel pitch P2 in the fluorescence imaging element 9 in this way makes it possible to capture the visible light VL with high resolution and to clearly capture the fluorescence FL.

[0191] As reference Figure 1 and Figure 6 As described in , etc., the imaging device 1 may include a long pass filter 8 disposed between the prism 6 and the fluorescence imaging element 9 to transmit the fluorescence FL. This configuration makes it possible to prevent unnecessary visible light VL from being input into the fluorescence imaging element 9.

[0192] As reference Figure 1 , Figure 3 and Figure 7 As described in, for example, the ratio of the diagonal length D2 of the effective pixel area of ​​the fluorescent imaging element 9 to the diagonal length D1 of the effective pixel area of ​​the visible light imaging element 7 can be greater than 0.7 and less than 1.4 (0.7≤(D2 / D1)<1.4). For example, in this way, it is possible to receive the fluorescent light FL with high sensitivity and clearly capture the fluorescent light FL.

[0193] As reference Figure 1 As described in, for example, the following configuration may be provided: light L after passing through the imaging lens 4 is input into the prism 6, the optical path lengths from the input into the prism 6 to the imaging visible light VL and the fluorescent light FL are different from each other, the visible light imaging element 7 is directly or indirectly fixed to the prism 6 to be located at the imaging position of the visible light VL, and the fluorescent light imaging element 9 is directly or indirectly fixed to the prism 6 to be located at the imaging position of the fluorescent light FL. This configuration only requires focusing of the visible light imaging element 7 to focus the fluorescent light imaging element 9, and facilitates capturing the visible light VL with high resolution and capturing the fluorescent light FL clearly.

[0194] As reference Figure 1 and Fig.10As described in , the long-pass filter 8 may have an optical axis length designed according to the optical path length difference between the optical path lengths of the visible light VL and the fluorescent light FL, so as to position the fluorescent imaging element 9 at the imaging position of the fluorescent light FL. The prism 6 may have an optical axis length designed according to the optical path length difference between the optical path lengths of the visible light VL and the fluorescent light FL, so as to position the visible light imaging element 7 at the imaging position of the visible light VL and the fluorescent light imaging element 9 at the imaging position of the fluorescent light FL. The imaging device 1 includes a gap portion G positioned between the prism 6 and at least one of the visible light imaging element 7 and the fluorescent light imaging element 9, wherein the gap portion G may have an optical axis length designed according to the optical path length difference between the optical path lengths of the visible light VL and the fluorescent light FL, so as to position the visible light imaging element 7 at the imaging position of the visible light VL and the fluorescent light imaging element 9 at the imaging position of the fluorescent light FL. For example, the visible light imaging element 7 and the fluorescent light imaging element 9 may be positioned in this manner.

[0195] As reference Fig.11 and Fig.12 As described in the foregoing, the fluorescence FL includes fluorescence FL1 (first fluorescence) and fluorescence FL2 (second fluorescence), the prism 6 separates the visible light VL, fluorescence FL1 and fluorescence FL2 included in the light L from the observation object S, and the fluorescence imaging element 9 includes a fluorescence imaging element 91 (first fluorescence imaging element) for capturing the fluorescence FL1 separated by the prism 6 and a fluorescence imaging element 92 (second fluorescence imaging element) for capturing the fluorescence FL2 separated by the prism 6, wherein the ratio of the pixel pitch P4 in the fluorescence imaging element 91 to the pixel pitch P3 in the visible light imaging element 7 and the ratio of the pixel pitch P5 in the fluorescence imaging element 92 to the pixel pitch P3 in the visible light imaging element 7 can both be greater than 1 and less than 5 (1≤(P4 / P3)<5 and 1≤(P5 / P3)<5). This configuration makes it possible to capture the visible light VL with high resolution and clearly capture the fluorescence FL1 and fluorescence FL2.

[0196] As reference Fig.11 As described in, for example, the ratio of the diagonal length D4 of the effective pixel area of ​​the fluorescent imaging element 91 to the diagonal length D3 of the effective pixel area of ​​the visible light imaging element 7 and the ratio of the diagonal length D5 of the effective pixel area of ​​the fluorescent imaging element 92 to the diagonal length D3 of the effective pixel area of ​​the visible light imaging element 7 can both be greater than 0.7 and less than 1.4 (0.7≤(D4 / D3)<1.4 and 0.7≤(D5 / D3)<1.4). For example, in this way, the fluorescent light FL1 and the fluorescent light FL2 can be received with high sensitivity and clearly captured.

[0197] As reference Fig.11As described in, the following configuration may be set: the optical path lengths from the visible light VL input into the prism 6 to the imaging, the fluorescence FL1, and the fluorescence FL2 are different from each other, the visible light imaging element 7 is directly or indirectly fixed to the prism 6 to be located at the imaging position of the visible light VL, the fluorescence imaging element 91 is directly or indirectly fixed to the prism 6 to be located at the imaging position of the fluorescence FL1, and the fluorescence imaging element 92 may be directly or indirectly fixed to the prism 6 to be located at the imaging position of the fluorescence FL2. This configuration only requires the focusing of the visible light imaging element 7 to focus the fluorescence imaging element 91 and the fluorescence imaging element 92, and facilitates capturing the visible light VL with high resolution and clearly capturing the fluorescence FL1 and the fluorescence FL2.

[0198] As reference Fig.10 and Fig.11 As described in , the imaging device 1 includes a long-pass filter 81 (a first long-pass filter) arranged between the prism 6 and the fluorescence imaging element 91 to transmit the fluorescence FL1, and a long-pass filter 82 (a second long-pass filter) arranged between the prism 6 and the fluorescence imaging element 92 to transmit the fluorescence FL2, wherein the long-pass filter 81 can have an optical axis length designed according to the optical path length difference between the optical path length of the visible light VL and the fluorescence FL1 to position the fluorescence imaging element 91 at the imaging position of the fluorescence FL1, and the long-pass filter 82 can have an optical axis length designed according to the optical path length difference between the optical path length of the visible light VL and the fluorescence FL2 to position the fluorescence imaging element 92 at the imaging position of the fluorescence FL2. The prism 6 may have an optical axis length designed according to the optical path length difference between the optical path lengths of the visible light VL, the fluorescent light FL1, and the fluorescent light FL2, so as to position the visible light imaging element 7 at the imaging position of the visible light VL, the fluorescent light imaging element 91 at the imaging position of the fluorescent light FL1, and the fluorescent light imaging element 92 at the imaging position of the fluorescent light FL2. The imaging device 1 includes a gap portion G positioned between the prism 6 and at least one of the visible light imaging element 7, the fluorescent light imaging element 91, and the fluorescent light imaging element 92, wherein the gap portion G may have an optical axis length designed according to the optical path length difference between the optical path lengths of the visible light VL, the fluorescent light FL1, and the fluorescent light FL2, so as to position the visible light imaging element 7 at the imaging position of the visible light VL, the fluorescent light imaging element 91 at the imaging position of the fluorescent light FL1, and the fluorescent light imaging element 92 at the imaging position of the fluorescent light FL2. For example, in this way, the visible light imaging element 7, the fluorescent light imaging element 91, and the fluorescent light imaging element 92 may be positioned.

[0199] As reference Figures 13 to 16As described in the examples above, the visible light VL includes green light VLG, blue light VLB and red light VLR, the fluorescent light FL includes infrared light FLIR, the prism 6 separates the green light VLG, blue light VLB, red light VLR and infrared light FLIR included in the light L from the observation object S, the visible light imaging element 7 includes a green light imaging element 7G for capturing the green light VLG separated by the prism 6, a blue light imaging element 7B for capturing the blue light VLB separated by the prism 6, and a red light imaging element 7R for capturing the red light VLR separated by the prism 6, and the fluorescent imaging element 9 includes an infrared imaging element 9IR for imaging the red light FLIR separated by the prism 6, wherein the ratio of the pixel pitch P7 in the infrared imaging element 9IR to the pixel pitch P6 in the green light imaging element 7G can be greater than 1 and less than 5 (1≤(P7 / P6)<5). This configuration makes it possible to capture the green light VLG, blue light VLB, red light VLR with high resolution and to clearly capture the infrared light FLIR.

[0200] As reference Fig.13 As described in the examples above, the ratio of the effective pixel area diagonal length D7 of the infrared imaging element 9IR to the effective pixel area diagonal length D6 of the green light imaging element 7G can be greater than 0.7 and less than 1.4 (0.7≤(D7 / D6)<1.4). For example, in this way, the infrared light FLIR can be received with high sensitivity and clearly captured.

[0201] As reference Fig.13 As described in, the following configuration may be set: the optical path lengths from the green light VLG and the infrared light FLIR input to the prism 6 to the imaging are different from each other, the green light imaging element 7G is directly or indirectly fixed to the prism 6 to be located at the imaging position of the green light VLG, and the infrared imaging element 9IR is directly or indirectly fixed to the prism 6 to be located at the imaging position of the infrared light FLIR. This configuration only requires the focusing of the green light imaging element 7G to focus the infrared imaging element 9IR, and facilitates capturing the green light VLG with high resolution and capturing the infrared light FLIR clearly.

[0202] As reference Fig.10 and Fig.13As described in , the imaging device 1 includes a long-pass filter 8IR disposed between the prism 6 and the infrared imaging element 9IR to transmit the infrared light FLIR, wherein the long-pass filter 8IR may have an optical axis length designed according to the optical path length difference between the optical path lengths of the green light VLG and the infrared light FLIR, so as to position the infrared imaging element 9IR at the imaging position of the infrared light FLIR. The prism 6 may have an optical axis length designed according to the optical path length difference between the optical path lengths of the green light VLG and the infrared light FLIR, so as to position the green light imaging element 7G at the imaging position of the green light VLG, and to position the infrared imaging element 9IR at the imaging position of the infrared light FLIR. The imaging device 1 includes a gap portion G, which is positioned between the prism 6 and at least one of the green light imaging element 7G and the infrared imaging element 9IR, wherein the gap portion G may have an optical axis length designed according to the optical path length difference between the optical path lengths of the green light VLG and the infrared light FLIR, so as to position the green light imaging element 7G at the imaging position of the green light VLG and the infrared imaging element 9IR at the imaging position of the infrared light FLIR. For example, in this way, the green light imaging element 7G and the infrared imaging element 9IR may be positioned.

[0203] refer to Figures 17 to 19 The described medical observation system (e.g., endoscope system 5000, microscope surgery system 5300, etc.) is also an aspect of the disclosed technology. The medical observation system includes an imaging device 1 that captures a surgical site. The imaging device 1 is configured as described above. In medical observation, visible light VL (ordinary light) can be captured with high resolution and fluorescent light FL (special light) can be captured clearly.

[0204] Note that the effects described in the present disclosure are merely examples and are not limited to the disclosed contents. There may be other effects.

[0205] Although the embodiments of the present disclosure have been described above, the technical scope of the present disclosure is not limited to the above embodiments themselves, and various changes can be made without departing from the gist of the present disclosure. In addition, components in different embodiments and modified examples can be appropriately combined.

[0206] Note that the present technology may also have the following configurations.

[0207] (1) An imaging device comprising:

[0208] a prism that separates visible light and fluorescence included in light from an observation object;

[0209] a visible light imaging element that captures the visible light separated by the prism; and

[0210] A fluorescence imaging element that captures the fluorescence separated by the prism, wherein

[0211] The ratio of the pixel pitch in the fluorescence imaging element to the pixel pitch in the visible light imaging element is 1 or more and less than 5.

[0212] (2) The imaging device according to (1), comprising

[0213] A long pass filter is disposed between the prism and the fluorescence imaging element to transmit the fluorescence.

[0214] (3) The imaging device according to (1) or (2), wherein:

[0215] The ratio of the diagonal length of the effective pixel area of ​​the fluorescence imaging element to the diagonal length of the effective pixel area of ​​the visible light imaging element is greater than 0.7 and less than 1.4.

[0216] (4) The imaging device according to any one of (1) to (3), wherein:

[0217] The light passing through the imaging lens is input into the prism.

[0218] The optical path lengths of visible light and fluorescence from input into the prism to image formation are different from each other.

[0219] The visible light imaging element is directly or indirectly fixed to the prism so as to be located at an imaging position of the visible light, and

[0220] The fluorescence imaging element is directly or indirectly fixed to the prism so as to be located at the imaging position of the fluorescence.

[0221] (5) The imaging device according to (4), comprising

[0222] A long pass filter is disposed between the prism and the fluorescence imaging element to transmit the fluorescence, wherein:

[0223] The long pass filter has an optical axis length designed according to the optical path length difference between visible light and fluorescence, so as to position the fluorescence imaging element at the imaging position of the fluorescence.

[0224] (6) The imaging device according to (4) or (5), wherein:

[0225] The prism has an optical axis length designed according to the optical path length difference between visible light and fluorescence to position the visible light imaging element at the imaging position of visible light and the fluorescence imaging element at the imaging position of fluorescence.

[0226] (7) The imaging device according to any one of (4) to (6), comprising:

[0227] a gap portion positioned between the prism and at least one of the visible light imaging element and the fluorescent imaging element, wherein

[0228] The gap has an optical axis length designed according to the optical path length difference between visible light and fluorescence to position the visible light imaging element at an imaging position of visible light and the fluorescence imaging element at an imaging position of fluorescence.

[0229] (8) The imaging device according to any one of (1) to (7), wherein

[0230] The fluorescence includes a first fluorescence and a second fluorescence,

[0231] The prism separates the visible light, the first fluorescence, and the second fluorescence included in the light from the observation object.

[0232] Fluorescence imaging components include:

[0233] a first fluorescence imaging element that captures the first fluorescence separated by the prism; and

[0234] a second fluorescence imaging element that captures the second fluorescence separated by the prism, and

[0235] The ratio of the pixel pitch in the first fluorescent imaging element to the pixel pitch in the visible light imaging element and the ratio of the pixel pitch in the second fluorescent imaging element to the pixel pitch in the visible light imaging element are both 1 or more and less than 5.

[0236] (9) The imaging device according to (8), wherein:

[0237] The ratio of the diagonal length of the effective pixel area of ​​the first fluorescent imaging element to the diagonal length of the effective pixel area of ​​the visible light imaging element and the ratio of the diagonal length of the effective pixel area of ​​the second fluorescent imaging element to the diagonal length of the effective pixel area of ​​the visible light imaging element are both greater than 0.7 and less than 1.4.

[0238] (10) The imaging device according to (8) or (9), wherein:

[0239] The light passing through the imaging lens is input into the prism.

[0240] The optical path lengths of the visible light, the first fluorescence, and the second fluorescence from the input into the prism to the image formation are different from each other.

[0241] The visible light imaging element is directly or indirectly arranged at the prism to be located at the imaging position of the visible light,

[0242] The first fluorescence imaging element is directly or indirectly fixed to the prism so as to be located at the imaging position of the first fluorescence, and

[0243] The second fluorescent imaging element is directly or indirectly fixed to the prism to be located at the imaging position of the second fluorescent light.

[0244] (11) The imaging device according to (10), comprising:

[0245] A first long pass filter disposed between the prism and the first fluorescent imaging element to transmit the first fluorescent light; and

[0246] A second long pass filter is arranged between the prism and the second fluorescence imaging element to transmit the second fluorescence, wherein,

[0247] The first long pass filter has an optical axis length designed according to the optical path length difference between the visible light and the optical path length of the first fluorescence, so as to position the first fluorescence imaging element at the imaging position of the first fluorescence, and

[0248] The second long pass filter has an optical axis length designed according to an optical path length difference between the visible light and the second fluorescent light, so as to position the second fluorescent light imaging element at an imaging position of the second fluorescent light.

[0249] (12) The imaging device according to (10) or (11), wherein:

[0250] The prism has an optical axis length designed according to the optical path length difference between the visible light, the first fluorescence and the second fluorescence, so as to position the visible light imaging element at the imaging position of the visible light, the first fluorescence imaging element at the imaging position of the first fluorescence, and the second fluorescence imaging element at the imaging position of the second fluorescence.

[0251] (13) The imaging device according to any one of (10) to (12), comprising

[0252] a gap portion positioned between the prism and at least one of the visible light imaging element, the first fluorescent imaging element, and the second fluorescent imaging element, wherein

[0253] The gap portion has an optical axis length designed according to the optical path length difference between the optical path lengths of the visible light, the first fluorescence, and the second fluorescence, so as to position the visible light imaging element at the imaging position of the visible light, the first fluorescence imaging element at the imaging position of the first fluorescence, and the second fluorescence imaging element at the imaging position of the second fluorescence.

[0254] (14) The imaging device according to any one of (1) to (13), wherein:

[0255] Visible light includes green, blue and red light.

[0256] Fluorescence includes infrared light,

[0257] The prism separates green light, blue light, red light, and infrared light included in the light from the observation object.

[0258] Visible light imaging components include:

[0259] a green light imaging element that captures the green light separated by the prism;

[0260] a blue light imaging element that captures the blue light separated by the prism; and

[0261] A red light imaging element that captures the red light separated by the prism,

[0262] The fluorescent imaging element includes an infrared imaging element that captures infrared light separated by a prism, and

[0263] The ratio of the pixel pitch in the infrared imaging element to the pixel pitch in the green light imaging element is greater than or equal to 1 and less than 5.

[0264] (15) The imaging device according to (14), wherein:

[0265] The ratio of the diagonal length of the effective pixel area of ​​the infrared imaging element to the diagonal length of the effective pixel area of ​​the green light imaging element is greater than 0.7 and less than 1.4.

[0266] (16) The imaging device according to (14) or (15), wherein:

[0267] The light passing through the imaging lens is input into the prism.

[0268] The optical path lengths of green light and infrared light from input into the prism to image formation are different from each other.

[0269] The green light imaging element is directly or indirectly fixed to the prism so as to be located at the imaging position of the green light, and

[0270] The infrared imaging element is directly or indirectly fixed to the prism to be located at an imaging position of the infrared light.

[0271] (17) The imaging device according to (16), comprising

[0272] A long pass filter is arranged between the prism and the infrared imaging element to transmit infrared light, wherein,

[0273] The long pass filter has an optical axis length designed according to an optical path length difference between the optical path lengths of green light and infrared light to position the infrared imaging element at an imaging position of the infrared light.

[0274] (18) The imaging device according to (16) or (17), wherein:

[0275] The prism has an optical axis length designed according to the optical path length difference between green light and infrared light to position the green light imaging element at the imaging position of green light and the infrared imaging element at the imaging position of infrared light.

[0276] (19) The imaging device according to any one of (16) to (18), comprising

[0277] a gap portion positioned between the prism and at least one of the green light imaging element and the infrared imaging element, wherein

[0278] The gap has an optical axis length designed according to the optical path length difference between green light and infrared light to position the green light imaging element at the imaging position of green light and the infrared imaging element at the imaging position of infrared light.

[0279] (20) A medical observation system comprising:

[0280] An imaging device that captures the surgical site, wherein

[0281] The imaging device includes:

[0282] a prism that separates visible light and fluorescent light included in the light from the surgical site;

[0283] a visible light imaging element that captures the visible light separated by the prism; and

[0284] a fluorescence imaging element that captures the fluorescence separated by the prism, and

[0285] The ratio of the pixel pitch in the fluorescence imaging element to the pixel pitch in the visible light imaging element is 1 or more and less than 5.

[0286] Reference numerals list

[0287] 1 Imaging device

[0288] 2 Light Source

[0289] 21 White light source

[0290] 22 Excitation light source

[0291] 3 Optical diagnostic components

[0292] 4 Imaging lens

[0293] 4a Input surface

[0294] 4b Output Surface

[0295] 5 Excitation light cutoff filter

[0296] 5a Input Surface

[0297] 5b Output surface

[0298] 6 Prism

[0299] 6a Input surface

[0300] 6b1 output surface

[0301] 6b2 output surface

[0302] 6b21 output surface

[0303] 6b22 output surface

[0304] 6bB output surface

[0305] 6bG output surface

[0306] 6bR output surface

[0307] 6bIR output surface

[0308] 61 blocks

[0309] 611 blocks

[0310] 612 blocks

[0311] 613 blocks

[0312] 62 pieces

[0313] 621 blocks

[0314] 622 blocks

[0315] 65 Dichroic film

[0316] 66 Dichroic film

[0317] 67 Dichroic film

[0318] 68 Dichroic film

[0319] 69 Dichroic film

[0320] 7 Visible light imaging element

[0321] 7a Light receiving surface

[0322] 7p pixels

[0323] 7a1 pixel area

[0324] 7a2 effective pixel area

[0325] 7B Blue light imaging element

[0326] 7G Green Light Imaging Element

[0327] 7R Red light imaging element

[0328] 8 Long pass filter

[0329] 8a Input surface

[0330] 8b Output surface

[0331] 81 Long pass filter

[0332] 82 Long pass filter

[0333] 8IR long pass filter

[0334] 9 Fluorescence imaging element

[0335] 9a Light receiving surface

[0336] 9p pixels

[0337] 9a1 pixel area

[0338] 9a2 effective pixel area

[0339] 91 Fluorescence imaging element

[0340] 92 Fluorescence imaging element

[0341] 9IR infrared imaging element

[0342] 10. Retaining member

[0343] 101 substrate

[0344] 102 Retaining rod

[0345] 102a One end

[0346] 102b The other end

[0347] 5000 Endoscope System (Medical Observation System)

[0348] 5300 Microscope Surgery System (Medical Observation System)

[0349] D1 effective pixel area diagonal length

[0350] D2 effective pixel area diagonal length

[0351] D3 effective pixel area diagonal length

[0352] D4 effective pixel area diagonal length

[0353] D5 effective pixel area diagonal length

[0354] D6 effective pixel area diagonal length

[0355] D7 effective pixel area diagonal length

[0356] G Gap

[0357] P1 Pixel Pitch

[0358] P2 Pixel Pitch

[0359] P3 pixel pitch

[0360] P4 pixel pitch

[0361] P5 Pixel Pitch

[0362] P6 pixel pitch

[0363] P7 Pixel Pitch

[0364] S Observation object

[0365] L Light

[0366] SL Light

[0367] VL Visible light

[0368] VLB Blu-ray

[0369] VLG Green Light

[0370] VLR Red Light

[0371] FL Fluorescence

[0372] FL1 Fluorescence

[0373] FL2 Fluorescence

[0374] FLIR Infrared

[0375] WL White Light

[0376] EL excitation light

[0377] W1 pixel size

[0378] W2 pixel size.

Claims

1. An imaging device, comprising: a prism that separates visible light and fluorescence included in light from an observation object; a visible light imaging element that captures the visible light separated by the prism; as well as a fluorescence imaging element, the fluorescence imaging element capturing the fluorescence separated by the prism, wherein A ratio of a pixel pitch in the fluorescent imaging element to a pixel pitch in the visible light imaging element is 1 or more and less than 5.

2. The imaging device according to claim 1, comprising A long pass filter is disposed between the prism and the fluorescence imaging element to transmit the fluorescence.

3. The imaging device according to claim 1, wherein: The ratio of the diagonal length of the effective pixel area of ​​the fluorescent imaging element to the diagonal length of the effective pixel area of ​​the visible light imaging element is greater than 0.7 and less than 1.

4.

4. The imaging device according to claim 1, wherein: The light passing through the imaging lens is input into the prism. The optical path lengths of the visible light and the fluorescence from input into the prism to image formation are different from each other, The visible light imaging element is directly or indirectly fixed to the prism to be located at the imaging position of the visible light, and The fluorescence imaging element is directly or indirectly fixed to the prism to be located at the imaging position of the fluorescence.

5. The imaging device according to claim 4, comprising A long pass filter is disposed between the prism and the fluorescence imaging element to transmit the fluorescence, wherein: The long pass filter has an optical axis length designed according to an optical path length difference between the visible light and the optical path length of the fluorescence, so as to position the fluorescence imaging element at an imaging position of the fluorescence.

6. The imaging device according to claim 4, wherein: The prism has an optical axis length designed according to the optical path length difference between the visible light and the fluorescence to position the visible light imaging element at the imaging position of the visible light and the fluorescence imaging element at the imaging position of the fluorescence.

7. The imaging device according to claim 4, comprising: a gap portion, the gap portion being positioned between the prism and at least one of the visible light imaging element and the fluorescent imaging element, wherein The gap portion has an optical axis length designed according to the optical path length difference between the visible light and the fluorescence to position the visible light imaging element at the imaging position of the visible light and the fluorescence imaging element at the imaging position of the fluorescence.

8. The imaging device according to claim 1, wherein: The fluorescence includes a first fluorescence and a second fluorescence, the prism separates the visible light, the first fluorescence, and the second fluorescence included in the light from the observation object, The fluorescent imaging element comprises: a first fluorescence imaging element that captures the first fluorescence separated by the prism; and a second fluorescence imaging element that captures the second fluorescence separated by the prism, and A ratio of a pixel pitch in the first fluorescent imaging element to a pixel pitch in the visible light imaging element and a ratio of a pixel pitch in the second fluorescent imaging element to a pixel pitch in the visible light imaging element are both greater than 1 and less than 5.

9. The imaging device according to claim 8, wherein: The ratio of the diagonal length of the effective pixel area of ​​the first fluorescent imaging element to the diagonal length of the effective pixel area of ​​the visible light imaging element and the ratio of the diagonal length of the effective pixel area of ​​the second fluorescent imaging element to the diagonal length of the effective pixel area of ​​the visible light imaging element are both greater than 0.7 and less than 1.

4.

10. The imaging device according to claim 8, wherein: The light passing through the imaging lens is input into the prism. The optical path lengths of the visible light, the first fluorescence, and the second fluorescence from input into the prism to image formation are different from each other, The visible light imaging element is directly or indirectly arranged at the prism to be located at the imaging position of the visible light, The first fluorescent imaging element is directly or indirectly fixed to the prism so as to be located at the imaging position of the first fluorescent light, and The second fluorescence imaging element is directly or indirectly fixed to the prism to be located at an imaging position of the second fluorescence.

11. The imaging device according to claim 10, comprising: a first long-pass filter, the first long-pass filter being arranged between the prism and the first fluorescence imaging element to transmit the first fluorescence; as well as a second long pass filter, the second long pass filter is arranged between the prism and the second fluorescence imaging element to transmit the second fluorescence, wherein, The first long pass filter has an optical axis length designed according to the optical path length difference between the visible light and the optical path length of the first fluorescence, so as to position the first fluorescence imaging element at the imaging position of the first fluorescence, and The second long pass filter has an optical axis length designed according to an optical path length difference between the visible light and the optical path length of the second fluorescence, so as to position the second fluorescence imaging element at an imaging position of the second fluorescence.

12. The imaging device according to claim 10, wherein: The prism has an optical axis length designed according to the optical path length difference between the visible light, the first fluorescence and the second fluorescence, so as to position the visible light imaging element at the imaging position of the visible light, the first fluorescence imaging element at the imaging position of the first fluorescence, and the second fluorescence imaging element at the imaging position of the second fluorescence.

13. The imaging device according to claim 10, comprising a gap portion, the gap portion being positioned between the prism and at least one of the visible light imaging element, the first fluorescent imaging element, and the second fluorescent imaging element, wherein The gap portion has an optical axis length designed according to the optical path length difference between the visible light, the first fluorescence and the second fluorescence, so as to position the visible light imaging element at the imaging position of the visible light, the first fluorescence imaging element at the imaging position of the first fluorescence, and the second fluorescence imaging element at the imaging position of the second fluorescence.

14. The imaging device according to claim 1, wherein: The visible light includes green light, blue light and red light, The fluorescence includes infrared light, the prism separates the green light, the blue light, the red light, and the infrared light included in the light from the observation object, The visible light imaging element comprises: a green light imaging element, the green light imaging element capturing the green light separated by the prism; a blue light imaging element that captures the blue light separated by the prism; and a red light imaging element that captures the red light separated by the prism, The fluorescent imaging element includes an infrared imaging element that captures the infrared light separated by the prism, and A ratio of a pixel pitch in the infrared imaging element to a pixel pitch in the green light imaging element is greater than or equal to 1 and less than 5.

15. The imaging device according to claim 14, wherein: The ratio of the diagonal length of the effective pixel area of ​​the infrared imaging element to the diagonal length of the effective pixel area of ​​the green light imaging element is greater than 0.7 and less than 1.

4.

16. The imaging device according to claim 14, wherein: The light passing through the imaging lens is input into the prism. The optical path lengths of the green light and the infrared light from input into the prism to image formation are different from each other, The green light imaging element is directly or indirectly fixed to the prism to be located at the imaging position of the green light, and The infrared imaging element is directly or indirectly fixed to the prism to be located at an imaging position of the infrared light.

17. The imaging device according to claim 16, comprising A long pass filter is arranged between the prism and the infrared imaging element to transmit the infrared light, wherein: The long pass filter has an optical axis length designed according to an optical path length difference between the optical path lengths of the green light and the infrared light, so as to position the infrared imaging element at an imaging position of the infrared light.

18. The imaging device according to claim 16, wherein: The prism has an optical axis length designed according to the optical path length difference between the green light and the infrared light to position the green light imaging element at the imaging position of the green light and to position the infrared imaging element at the imaging position of the infrared light.

19. The imaging device according to claim 16, comprising a gap portion, the gap portion being positioned between the prism and at least one of the green light imaging element and the infrared imaging element, wherein The gap portion has an optical axis length designed according to the optical path length difference between the green light and the infrared light to position the green light imaging element at the imaging position of the green light and to position the infrared imaging element at the imaging position of the infrared light.

20. A medical observation system, comprising: An imaging device that captures the surgical site, wherein The imaging device comprises: a prism that separates visible light and fluorescent light included in light from the surgical site; a visible light imaging element that captures the visible light separated by the prism; and a fluorescence imaging element that captures the fluorescence separated by the prism, and A ratio of a pixel pitch in the fluorescent imaging element to a pixel pitch in the visible light imaging element is 1 or more and less than 5.

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