Camera unit, camera head, and method for attaching the camera unit

Abstract

There is a demand for a shooting unit that is easy to handle. [Solution] The photographing unit 1 includes an optical element 80, for example a gradient index lens, a joint part 70 that can be fixed to the optical element 80, and a camera head 10 that is located closer to the optical element 80 and has a tip part 12 that receives light from the optical element 80 and emits light to the optical element 80. A male thread 13 is formed around the periphery of the tip part 12. The joint part 70 has an attachment part 71 into which the male thread 13 is screwed. The tip part 12 is disposed inside the joint part 70. The photographing unit 1 allows the distance of the camera head relative to the gradient index lens to be adjusted with high precision.

Description

[Technical Field]

[0001] The present invention relates to a photographing unit, a camera head, a method for manufacturing a camera head, and a method for attaching a photographing unit, which are used for observing an object to be observed. [Background technology]

[0002] 2. Description of the Related Art Conventionally, various types of camera heads and photographing units using the same have been used in endoscopes for biological tissues and industrial endoscopes, for example.

[0003] For example, Patent Document 1 listed below discloses the structure of a camera head that houses an imaging element and a light source, emits light from the tip, and captures an image of light incident from an object to be observed.

[0004] Furthermore, for example, Patent Document 2 listed below describes the structure of an imaging unit that includes a lens holder that houses an objective lens group in a hollow portion, and an imaging holder that houses a prism and an imaging element.

[0005] Furthermore, for example, Patent Documents 3 to 5 listed below describe the configuration of an imaging unit using a gradient index lens (GRIN lens). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent No. 7488619 [Patent Document 2] Japanese Patent Application Laid-Open No. 2014-119474 [Patent Document 3] Patent re-publication WO17 / 170662 [Patent Document 4] Special Publication No. 2011-510338 [Patent Document 5] Patent Publication No. 2005-533530 Summary of the Invention [Problem to be solved by the invention]

[0007] Incidentally, it is important to make a photographing unit that is composed of multiple components, including, for example, a camera head, optical elements for observing an object, etc. For example, in a photographing unit that has a camera head and a gradient index lens attached to the front of the camera head, the part where the lens is attached to the camera head must be attached with high precision in order to detect light from the lens, and it is also desirable that the part be easy to attach.

[0008] The present invention has been made in view of the above points, and has as its object to provide a photographing unit, a camera head, a method for manufacturing a camera head, and a method for attaching a photographing unit that can be easily handled. [Means for solving the problem]

[0009] The photographing unit of this first invention comprises an optical element, a joint portion that can be fixed to the optical element, and a camera head that is located closer to the optical element and has a tip portion that receives light from the optical element and emits light to the optical element, a male screw formed around the tip portion, the joint portion having an attachment portion into which the male screw is screwed, and the tip portion is positioned inside the joint portion.

[0010] With this configuration, the distance of the camera head to the optical element can be adjusted with high precision, and the photographing unit can be easily handled.

[0011] In addition, the photographing unit of the second invention is different from the photographing unit of the first invention in that the optical element is a gradient index lens that extends in the longitudinal direction and adjusts the path of light between the object to be observed, the camera head has a camera module provided near the tip, a light source arranged behind the camera module, and an optical fiber extending from the light source to near the tip, and the tip of the optical fiber has an exit portion configured to be able to emit at least a portion of the light guided from the light source in a direction different from the longitudinal direction of the gradient index lens.

[0012] With this configuration, light from the light source can be efficiently emitted to the observation object via the gradient index lens.

[0013] Furthermore, the photographing unit of the third invention differs from the second invention in that the refractive index gradient lens, joint portion, and camera head are arranged in the longitudinal direction of the refractive index gradient lens, the output portion is an inclined portion which is the end face of the tip of the optical fiber formed so as to be inclined with respect to the longitudinal direction of the refractive index gradient lens, and the inclined portion is formed so as to be inclined so as to move away rearward from the tip in the longitudinal direction of the refractive index gradient lens as it approaches the outside of the center of the tip in a direction perpendicular to the longitudinal direction of the refractive index gradient lens.

[0014] With this configuration, light from the light source can be more efficiently emitted to the observation object via the gradient index lens.

[0015] Furthermore, the photographing unit of the fourth invention differs from the second invention in that the camera head has a housing having a portion where a male screw is formed, and each portion of the camera head is housed inside the housing, and the housing includes a first cylindrical portion which is a cylindrical portion located closer to the tip end, a second cylindrical portion which is a cylindrical portion located closer to the rear end opposite the tip end and in which at least a light source is arranged inside, and an insulating portion which is arranged between the first cylindrical portion and the second cylindrical portion and is made of a material with lower thermal conductivity than the second cylindrical portion.

[0016] This configuration makes it difficult for heat emitted from the light source to be transmitted to the tip of the camera head, and prevents the heat from affecting the object being observed.

[0017] In addition, the photographing unit of the fifth invention is a photographing unit in which, compared to the second invention, the camera head is arranged near the tip and has a guide that positions the camera module and the optical fiber (in the radial direction).

[0018] With this configuration, the camera head can be easily assembled by positioning the camera module and the optical fiber in ideal positions.

[0019] In addition, the photographing unit of the sixth invention is a photographing unit in which, compared to the second invention, the camera head has a first filter arranged between the light source and the optical fiber, and a second filter arranged to allow light incident on the camera module to pass through.

[0020] This configuration allows for flexible design of the structure of the camera head having two types of filters.

[0021] Furthermore, the photographing unit of the seventh invention is a photographing unit in which, compared to the first invention, the camera head has a filter arranged near the tip end that transmits light entering the camera head and light exiting the camera head, and the filter has a transparent substrate, a first transmitting portion arranged on the substrate that transmits the exiting light, and a second transmitting portion arranged on the substrate that transmits the incident light.

[0022] With this configuration, two types of filters can be arranged on the same substrate to form a compact camera head.

[0023] In addition, the photographing unit of the eighth invention is a photographing unit in which, compared to the first invention, the optical element extends in the longitudinal direction, has a rear end and a side, and is equipped with a guide member that is positioned near the rear end of the optical element and is configured to direct a portion of the light emitted from the tip of the camera head into the side of the optical element.

[0024] With this configuration, light from the light source can be efficiently incident on the optical element.

[0025] In addition, the photographing unit of the ninth invention is a photographing unit in which, compared to the eighth invention, the guide member has a reflecting portion at a position forward of the rear end of the optical element that reflects light incident from behind toward the inside where the side of the optical element is located.

[0026] With this configuration, light from the light source can be efficiently incident on the optical element.

[0027] Furthermore, the photographing unit of the tenth invention differs from the first invention in that the optical element is a member extending in the longitudinal direction, and is provided with a fixing member attached to the end of the optical element that is closer to the camera head in the longitudinal direction, and a groove is formed on the outer periphery of the fixing member, and the optical element is attached to the joint part such that the contact surface of the fixing member in the longitudinal direction is in contact with a part of the joint part and the outer periphery faces a part of the joint part, and adhesive is arranged between the groove and the joint part.

[0028] With this configuration, the positional relationship between the optical element and the joint portion in the longitudinal direction can be set with high precision, and the joint portion can be reliably fixed to the optical element.

[0029] Furthermore, the camera head of the eleventh invention is a camera head that can be used in the photographing unit described in the first invention, and has a housing and a camera module provided near the tip of the housing, and a male screw that can be screwed into the mounting portion of the joint part is formed around the tip of the housing.

[0030] With this configuration, it is possible to provide a camera head to which an optical element can be easily attached and used.

[0031] Furthermore, the twelfth invention provides a method for manufacturing a camera head, which includes a male screw that can be screwed into a joint portion of a photographing unit and a filter arranged near the tip end where the joint portion is attached, and is configured so that light that passes through a first transparent portion in a part of the filter is emitted toward the joint portion, and light that enters from the joint portion is transmitted through a second transparent portion in a part of the filter, and includes the steps of preparing a first member having the first transparent portion, preparing a second member having the second transparent portion, partially arranging the first member and the second member on a transparent substrate, cutting the substrate on which the first member and the second member are arranged into the shape of the filter, and arranging the cut-out filter near the tip end.

[0032] With this configuration, it is possible to easily and reliably manufacture a camera head equipped with a filter having two types of transmitting portions.

[0033] Furthermore, the method for attaching a photographing unit of the thirteenth invention is a method for attaching a photographing unit according to any one of the first to tenth inventions to a subject organism, and includes the steps of fixing a joint portion to an optical element, attaching the optical element to the subject organism, and screwing the tip of a camera head into the attachment portion of the joint portion to attach the camera head to the joint portion.

[0034] With this configuration, it is possible to easily place the optical element in an appropriate position and then perform observation using the camera head.

[0035] Furthermore, the method of attaching a photographing unit of the fourteenth invention differs from the thirteenth invention in that it includes a step of fixing a stopper at a position a predetermined distance rearward from the tip of the optical element, and the step of attaching the optical element to the subject organism is a method of attaching a photographing unit in which the optical element is attached to the subject organism so that the stopper is positioned at a predetermined position relative to the subject organism.

[0036] With this configuration, the optical elements can be easily arranged in appropriate positions.

[0037] Furthermore, the method of attaching a photographing unit of the fifteenth invention is different from the thirteenth invention in that a fixing member is attached to the end of the optical element, a groove portion is formed on the outer periphery of the fixing member, and the step of fixing the joint portion includes injecting adhesive between the joint portion and the groove portion through a hole provided in the joint portion with the outer periphery of the fixing member inserted inside the joint portion.

[0038] With this configuration, the joint portion can be reliably fixed to the optical element.

[0039] Furthermore, the method for attaching a photographing unit of the sixteenth invention is a method for attaching a photographing unit in which, compared to the thirteenth invention, the step of attaching the camera head to the joint part includes adjusting the position of the camera head relative to the joint part so as to obtain a desired light emission or incidence state between the camera head and the optical element, and fixing the position of the camera head relative to the joint part with a fixing means.

[0040] With this configuration, it is possible to easily place the optical element in an appropriate position and then perform reliable observation using the camera head. [Effects of the Invention]

[0041] According to the present invention, the photographing unit can be easily handled. [Brief explanation of the drawings]

[0042] [Figure 1] FIG. 1 is a diagram illustrating a configuration of an imaging system according to an embodiment of the present invention. [Figure 2] Block diagram of the imaging system [Figure 3] Side cross-sectional view of the same photographing unit [Figure 4] Cross section of line AA in Figure 3 [Figure 5] Cross section of line CC in Figure 3 [Figure 6] FIG. 10 is an enlarged side cross-sectional view of the photographing unit in the vicinity of the joint portion. [Figure 7] A view of the imaging unit from the tip side in the longitudinal direction [Figure 8] FIG. 10 is a side view of the fixing member of the camera head. [Figure 9] FIG. 10 is a diagram illustrating the configuration of the filter in the camera head. [Figure 10] 1 is a diagram illustrating an example of a manufacturing method of the filter. [Figure 11] FIG. 1 is a first diagram illustrating a manufacturing method of the photographing unit; [Figure 12] FIG. 2 is a second diagram illustrating a manufacturing method of the photographing unit. [Figure 13] A view of the joint part of the same photography unit viewed from the rear end in the longitudinal direction [Figure 14] FIG. 1 is a diagram illustrating an example of use of an imaging system according to an embodiment of the present invention. [Figure 15] FIG. 1 is a first diagram illustrating an example of a method for attaching the photographing unit to a subject organism. [Figure 16] FIG. 2 is a second diagram illustrating an example of a method for attaching the photographing unit to a subject organism. [Figure 17] 10 is a side cross-sectional view of a photographing unit according to a second embodiment of the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0043] Hereinafter, embodiments of a photographing unit and an imaging system using the same will be described with reference to the drawings. Note that components with the same reference numerals in the embodiments have roughly the same configuration, and therefore repeated description may be omitted.

[0044] In the following description, the direction perpendicular to the longitudinal direction of the tubular camera head is sometimes referred to as the radial direction, and the direction along the arc centered on the central axis of the camera head along the longitudinal direction is sometimes referred to as the circumferential direction. Also, in the following description, the direction toward the longitudinal tip is sometimes referred to as the "front," and the opposite direction is sometimes referred to as the "rear." For example, while certain directions may be used to describe the shape and positional relationship of various components, these directions are merely for the convenience of explanation and do not limit the orientation or posture of the devices according to the present invention during use. Furthermore, expressions indicating directions and states such as horizontal, vertical, and orthogonal only indicate that they can be roughly understood as such and are not necessarily to be interpreted strictly as such.

[0045] (Embodiment 1)

[0046] The outline of the first embodiment is as follows. In this embodiment, the photographing unit has a camera head, a joint attached to the tip of the camera head, and an optical element that can be fixed to the joint. The joint is configured to be able to be screwed onto the tip of the camera head. Note that a gradient index lens, for example, can be used as the optical element.

[0047] The camera head may include a camera module provided near the tip, a light source behind the light source, and an optical fiber extending from the light source to the vicinity of the tip. The tip of the optical fiber may be inclined, and may be configured to allow light to be appropriately incident using an optical element. The camera head may be provided with a filter that transmits light from the light source and light incident on the camera module. The filter may be located between the light source and the optical fiber and at a position where light incident on the camera module is transmitted. The filter may also be located near the tip and have a transmission portion through which light emitted onto the substrate is transmitted and a transmission portion through which light incident on the substrate is transmitted.

[0048] The housing of the camera head may be configured to have a heat insulating section between the tip and the portion where the light source is provided, so that heat from the light source is less likely to be transmitted to the tip.

[0049] An example of the configuration of such an imaging unit and an imaging system using the same will be described below.

[0050] Fig. 1 is a diagram illustrating the configuration of an imaging system 1000 according to an embodiment of the present invention. Fig. 2 is a block diagram of the imaging system 1000.

[0051] As shown in the figure, the imaging system 1000 includes a photographing unit 1 having a camera head 10 and an image acquisition device 500. The imaging system 1000 can be used as an endoscope for observing and inspecting various tissues and organs of living organisms, an industrial endoscope, or the like. That is, the imaging system 1000 can be used in various fields, such as industrial, medical, and scientific. The imaging system 1000 is configured to acquire imaging results of an imaging area near the tip of the photographing unit 1. The imaging system 1000 is configured to record the imaging results as images or output them to an internal or external output device.

[0052] As an example, the imaging system 1000 can be used to capture images for acquiring information (hereinafter, sometimes referred to as biological information) regarding the state of tissues or organs (hereinafter, sometimes referred to as target sites) inside the living body of a test subject organism. Here, the test subject organism refers to animals such as mammals and other vertebrates, and may also be referred to as test animals. However, the test subject organism is not limited to these and also includes invertebrates such as insects and other worms.

[0053] Biometric information includes, for example, images showing the condition of the target area captured by the imaging unit, other information, and numerical values, as well as information about the condition of the target area obtained based on them (e.g., assessment results, etc.).

[0054] The image may be a still image or a moving image (video). A moving image may be considered to include multiple still images. Furthermore, the format of the data recorded or output as an image does not matter.

[0055] In addition, outputting information or outputting information to a device includes expressions such as displaying the information on a display or the like, printing the information on a medium using a printer or the like, transmitting the information to another device over a network, and handing it over to subsequent processing in information processing performed on a computer or the like.

[0056] The camera head 10 of the photographing unit 1 has a camera module 30 and a light source 40. In this embodiment, the light source 40 has, for example, a first light source section 41 and a second light source section 42 that emit light with different wavelengths. There may be more types of light sources. A more specific structure of the photographing unit 1 will be described later.

[0057] The photographing unit 1 is connected to the image acquisition device 500 via a cable 590. The cable 590 includes, for example, a signal line for communicating with the camera module 30, and an electric wire for supplying power to drive the camera module 30 and the light source 40. The cable 590 is configured to be flexible, but is not limited to this.

[0058] The image acquisition device 500 is a device that includes, for example, a computer or the like and is configured to be able to capture images by driving the camera head 10 of the photographing unit 1. In this embodiment, the image acquisition device 500 is configured to be able to record the captured image results and output the captured image results to an external terminal device 600 or the like and display them on a display of the terminal device 600 or the like. Note that the image acquisition device 500 may itself have a display and be configured to be able to display captured images. The image acquisition device 500 may be, for example, a personal computer itself. In this embodiment, the imaging system 1000 may be understood to include the terminal device 600.

[0059] In this embodiment, the image acquisition device 500 includes, for example, a storage unit 510, a reception unit 530, an image acquisition unit 540, a camera head drive unit 550, a communication unit 560, and a power supply 570.

[0060] The power supply 570 supplies power to drive each component of the image acquisition device 500. The power supply 570 also serves as the power source for the power supplied to the photographing unit 1. The power supply 570 is, for example, a battery, but is not limited to this. The photographing unit 1 may also have its own battery or be configured to receive power from another power source.

[0061] The storage unit 510 is preferably a non-volatile recording medium, but can also be realized as a volatile recording medium. The storage unit 510 stores each piece of information acquired by the image acquisition device 500. The process by which the information is stored is not limited to a specific process. For example, the information may be stored via a recording medium, or information transmitted via a communication line or the like may be stored, or information input via an input device may be stored. The information may be stored temporarily in the storage unit 510.

[0062] Note that the storage unit 510 may be a recording medium that is a removable medium. In this case, the recording medium can be removed from the image acquisition device 500, making it possible to read the information stored in the storage unit 110 by an external device or the like.

[0063] The reception unit 530 receives the imaging results from the camera head 10, information received by the communication unit 560, and the like as information input to the image acquisition device 500. The received information is temporarily or long-term accumulated in the storage unit 510, or is used in processing by other units.

[0064] The receiving unit 530 may be capable of receiving information input by an input means. The input means may be, for example, a numeric keypad, a keyboard, a mouse, a menu screen, or any other means. In this case, the receiving unit 530 may be realized by a device driver for the input means such as the numeric keypad or keyboard, or control software for the menu screen.

[0065] The image acquisition unit 540 acquires images captured by the camera head 10. That is, the image acquisition unit 540 acquires, as an image, the imaging results acquired by the camera module 30 of the camera head 10 and transmitted to the image acquisition device 500 via the cable 590. The image acquisition unit 540 is configured to be able to record the acquired images in the storage unit 510.

[0066] The camera head driving unit 550 is configured to supply power to the camera module 30 and light source 40 of the camera head 10, drive each unit, and control the operation of each unit.

[0067] Image acquisition unit 540 and camera head drive unit 550 are configured to be operable by, for example, a computer executing a predetermined control program, but are not limited to this.

[0068] The communication unit 560 connects the image acquisition device 500 to an external device so that the image acquisition device 500 can communicate with the external device. The communication unit 560 is realized, for example, by a wireless or wired communication means, but may also be realized by a means for receiving broadcasts or a broadcasting means. In this embodiment, the communication unit 560 is configured to be able to communicate with, for example, an external terminal device 600 and transmit images captured by the camera head 10 to the terminal device 600. In other words, the image acquisition device 500 can output images captured using the camera head 10.

[0069] The image acquisition unit 540 may be configured to acquire information by performing predetermined information processing and record the acquired information in the storage unit 510. For example, the image acquisition unit 540 may be configured to acquire biometric information based on information acquired by the photographing unit 1. For example, by automatically performing information processing in accordance with the purpose of observation and storing the acquired biometric information or transmitting it to an external device, the user can efficiently perform observation, etc.

[0070] Next, the structure of the photographing unit 1 according to this embodiment will be described.

[0071] Fig. 3 is a side cross-sectional view of the photographing unit 1. Fig. 4 is a cross-sectional view taken along line AA in Fig. 3. Fig. 5 is a cross-sectional view taken along line CC in Fig. 3. Fig. 6 is a side cross-sectional view showing an enlarged view of the vicinity of the joint part 70 of the photographing unit 1. Fig. 7 is a view of the photographing unit 1 viewed from the tip side in the longitudinal direction.

[0072] In these drawings and the following similar cross-sectional views, hatching indicates cross sections of members, but for convenience of illustration, not all cross sections of members are necessarily hatched.

[0073] The outline of the structure of the photographing unit 1 is as follows.

[0074] The photographing unit 1 includes a camera head 10, a joint section 70, and an optical element 80. As shown in the figure, the photographing unit 1 has an elongated shape overall. In the longitudinal direction (the left-right direction in FIG. 3), the optical element 80 is attached to the tip section 12 of the camera head 10 via the joint section 70. That is, the tip section 12 of the camera head 10 is located on the side closer to the optical element 80, and is configured so that light from the optical element 80 enters the tip section 12 and exits from the tip section 12 to the optical element 80.

[0075] In this embodiment, a male thread 13 is formed around the periphery of tip portion 12 of camera head 10. Tip portion 12 is disposed in a mounting portion 71 provided inside joint portion 70. That is, mounting portion 71 is provided with a female thread that engages with male thread 13, and camera head 10 is joined to joint portion 70 by screwing male thread 13 into mounting portion 71.

[0076] The joint section 70 is configured to be able to fix the optical element 80. The optical element 80 is fixed to the joint section 70, and is arranged so as to be aligned with the camera head 10 in the longitudinal direction.

[0077] In this embodiment, the optical element 80 is configured using a gradient index (GRIN) lens 81. The gradient index lens 81 has a cylindrical shape. That is, the gradient index lens 81 is a member extending in the longitudinal direction, and adjusts the path of light between the lens and the object to be observed. The optical element 80 is arranged so that the longitudinal direction (axial direction) of the gradient index lens 81 is the same as the longitudinal direction of the photographing unit 1. In this embodiment, the optical element 80 may be considered to include the gradient index lens 81 and other associated members (for example, a fixing member 90, etc.).

[0078] The gradient index lens 81 is fixed to the joint part 70 via a fixing member 90, as will be described later. The gradient index lens 81 is arranged so that a lens rear end part 82, which is the end face opposite to the side facing the object to be observed in the longitudinal direction, faces the tip part 12 of the camera head 10. In this embodiment, most of the lens side surface 83 of the gradient index lens 81 is exposed to the outside.

[0079] The specific structure of the camera head 10 is as follows.

[0080] The camera head 10 has an elongated shape overall. In this embodiment, the camera head 10 has a generally cylindrical shape overall. The camera head 10 may be formed in a prismatic shape, or may have partial irregularities. FIG. 3 can be said to show a cross section of the camera head 10 taken along a plane passing through the central axis thereof.

[0081] The camera head 10 includes, for example, a housing 20, a camera module 30, a light source 40, an optical fiber 45, a filter 50, and a guide 25.

[0082] The housing 20 is formed in a cylindrical shape. It may be said that the housing 20 is formed in a tubular shape. The material of the housing 20 is not important. It may be metal, ceramic, resin, or anything else. Each part of the camera head 10 is housed inside the housing 20. It may be said that each part of the camera head 10 is located inside the housing 20. It may also be said that each part of the camera head 10 is located inside the inner circumferential surface of the housing 20 in the radial direction (the direction toward or away from the central axis of the camera head 10). The inner circumferential surface of the housing 20 has a cylindrical shape.

[0083] In this embodiment, the housing 20 is configured as a cylinder having two portions with different diameters in the longitudinal direction. The housing 20 is configured so that the outer diameter of the portion on the tip end 12 side where the male thread 13 is formed is smaller than the outer diameter of the portion further rearward. The outer diameter of the housing 20 may be substantially the same in the longitudinal direction. The housing 20 may have, for example, a rectangular cylindrical portion or a portion with irregularities.

[0084] In this embodiment, the housing 20 has a first cylindrical portion 21 and a second cylindrical portion 22. The first cylindrical portion 21 is a portion closer to the tip portion 12. The first cylindrical portion 21 is formed in a cylindrical shape. The male thread 13 is formed on the outer periphery of the first cylindrical portion 21. The second cylindrical portion 22 is a portion closer to the rear end portion 19, opposite the tip portion 12. The second cylindrical portion 22 is a portion formed in a cylindrical shape. The outer diameter of the second cylindrical portion 22 is larger than the outer diameter of the first cylindrical portion 21. The inner diameter of the second cylindrical portion 22 is larger than the inner diameter of the first cylindrical portion 21. As will be described later, a light source 40 is arranged inside the second cylindrical portion 22.

[0085] In this embodiment, the housing 20 has a heat insulating portion 23. The heat insulating portion 23 is disposed between the first cylindrical portion 21 and the second cylindrical portion 22. The heat insulating portion 23 is formed at a position closer to the rear end portion 19 than the first cylindrical portion 21. The housing 20 is configured with the first cylindrical portion 21, the rear end portion 19, and the second cylindrical portion 22 lined up in this order in the longitudinal direction.

[0086] The heat insulating portion 23 is formed of a material having a lower thermal conductivity than the second cylindrical portion 22. In addition, in the present embodiment, the heat insulating portion 23 is formed of a material having a lower thermal conductivity than the first cylindrical portion 21. Specifically, for example, the first cylindrical portion 21 and the second cylindrical portion 22 are each made of metal, and the heat insulating portion 23 is formed using a material such as resin or ceramic. This makes it more difficult for heat from the second cylindrical portion 22 to be transferred to the first cylindrical portion 21, compared to when the entire housing 20 is made of a material with high thermal conductivity, such as metal. This makes it possible to prevent the heat generated by the light source 40, etc. from affecting the imaging target area of a subject using the imaging unit.

[0087] In this embodiment, the first cylindrical portion 21, the heat insulating portion 23, and the second cylindrical portion 22 are each molded separately. The respective components are combined together by adhesive or the like to form a single housing 20, thereby forming the housing 20. For example, the first cylindrical portion 21 and the heat insulating portion 23 are formed to have roughly the same inner and outer diameters and are joined to form a single cylinder. The second cylindrical portion 22 is formed to have an inner diameter slightly larger than the outer diameter of the heat insulating portion 23. The second cylindrical portion 22 is joined to the heat insulating portion 23 in a state in which the portion of the second cylindrical portion 22 on the front end portion 12 side covers the portion of the heat insulating portion 23 on the rear end portion 19 side.

[0088] The configuration of the housing 20 is not limited to this, and for example, at least one of the first cylindrical portion 21 and the second cylindrical portion 22 and the heat insulating portion 23 may be integrally molded and combined. Alternatively, the housing 20 may be formed by cutting or the like on a base material that is integrally formed using a different material only for the portion corresponding to the heat insulating portion 23. Alternatively, the heat insulating portion 23 may be configured to have insertion portions that open on both the front end portion 12 side and the rear end portion 19 side, and the cylindrical portions 21 and 22 may be inserted into each opening to form one housing 20.

[0089] The housing 20 does not necessarily have to have such a heat insulating portion 23. In this case, for example, the housing 20 may be formed by processing a single base material or a tubular member, or the housing 20 may be formed by molding.

[0090] The camera module 30 is a module in which an imaging element and an optical system such as a lens are packaged. The camera module 30 may have a known structure, for example. The camera module 30 has a structure in which a light receiving unit 32, which is located at the tip end of the camera head 10 and into which light to be captured is incident, an optical system including a lens, and an imaging element are arranged side by side in the longitudinal direction of the camera head 10. Wiring (not shown) connected to the imaging element is connected to the rear end of the camera module 30, i.e., the rear end of the imaging element. The wiring can be gathered into a cable 590 and connected to the image acquisition device 500, etc.

[0091] In this embodiment, the camera module 30 has a rectangular prism shape formed so that the longitudinal direction of the camera head 10 corresponds to the height direction. That is, the outer surface (peripheral side surface) of the camera module 30 is roughly composed of four substantially flat portions. Note that the camera module 30 is not limited to a rectangular prism shape, and may be formed to have a triangular prism shape or other polygonal prism shape. It may also be cylindrical or have other shapes.

[0092] The light source 40 is a light source that irradiates the imaging area when capturing an image using the camera head 10. The light source 40 is, for example, an LED chip, but is not limited to this. The light source 40 may be, for example, a laser diode or other type of light source. The light source 40 is connected to, for example, an electric wire (not shown) that is wired through a cable 590, and is turned on when power is supplied from the image capture device 500 or the like. The light source 40 has, for example, a rectangular parallelepiped shape, but is not limited to this and may have other shapes, for example, a cylindrical shape, a coin shape, a flat plate shape, or the like.

[0093] The camera head 10 has two or more light sources 40. For example, in this embodiment, four light sources 40 are provided. Two of the four light sources 40 are first light source units 41, and the other two are second light source units 42. The first light source unit 41 and the second light source unit 42 are, for example, LED chips having an approximately rectangular parallelepiped shape as a whole, and are arranged to emit light from their front surfaces. The first light source unit 41 and the second light source unit 42 are configured to emit light of different wavelengths. In this embodiment, the provision of the first light source unit 41 and the second light source unit 42 allows the structure of the optical fiber 45 that guides the light from each light source unit forward to be simplified. Furthermore, the amount of light irradiated from the camera head 10 can be easily adjusted for each wavelength.

[0094] The number of light sources 40 is not limited to this. It is sufficient that two or more light sources 40 are provided. Of the two or more light sources 40, it is preferable that at least two are configured to emit light of different wavelengths, as in the present embodiment. For example, the camera head 10 may be provided with one first light source unit 41 and one second light source unit 42. However, this is not limited thereto, and the first light source unit 41 and the second light source unit 42 may be configured to emit light of the same wavelength. Alternatively, one light source 40 or two or more light sources 40 that emit light of the same wavelength may be provided, and the light emitted from the light source 40 may pass through filters that transmit light in different wavelength bands, thereby enabling the camera head 10 to irradiate light of two or more wavelengths.

[0095] As shown in the figure, each light source 40 is disposed at a position farther from the tip end 12 than the camera module 30 in the longitudinal direction. In other words, each light source 40 is located rearward of the camera module 30. It can be said that each light source 40 is behind the camera module 30 when viewed from the front longitudinal direction of the camera head 10 (the tip end 12 side). In this embodiment, most of the camera module 30 is disposed inside the first cylindrical portion 21, and the light source 40 is disposed inside the second cylindrical portion 22. As such, since the light source 40 is disposed away from the tip end 12 and the housing 20 is provided with the heat insulating portion 23, heat generated by the light source 40 is less likely to be transmitted to the tip end 12, preventing the heat from affecting the subject. Furthermore, each light source 40 is disposed at a position where a portion of the light source 40 overlaps with the camera module 30 when viewed from the front longitudinal direction. This allows each component of the camera head 10 to be accommodated in a housing 20 with a smaller diameter.

[0096] Furthermore, in the camera head 10, at least two of the light sources 40 are located at different positions in the longitudinal direction. Of the at least two light sources 40, the rear end of at least one light source 40 is located forward of the front end of the other at least one light source 40. By having the at least two light sources 40 located at different positions in the longitudinal direction in this manner, each light source 40 can be housed in a housing 20 with a smaller diameter.

[0097] More specifically, in the present embodiment, the two first light source units 41 of the camera head 10 are positioned in front of the two second light source units 42. In other words, it may be said that the camera module 30, the two first light source units 41, and the two second light source units 42 are arranged in this order from the side closest to the tip end 12 in the longitudinal direction. It may be said that each of the two first light source units 41 is sandwiched between the rear end of the camera module 30 and the front end of the second light source unit 42.

[0098] As shown in FIG. 4 , in this embodiment, two first light source units 41 are arranged radially outward from the cable 590, with the cable 590 sandwiched between the two first light source units 41. Furthermore, two second light source units 42 are also arranged radially outward from the cable 590, with the cable 590 sandwiched between the two second light source units 42. In this embodiment, the first light source unit 41 and the second light source unit 42 are arranged so as to partially overlap when viewed from the front in the longitudinal direction. Note that the positional relationship between the first light source unit 41 and the second light source unit 42 when viewed from the front in the longitudinal direction is not limited to this. It is preferable that two or more light sources 40 at different positions in the longitudinal direction are arranged so that the positions from which they emit light are different from each other when viewed from the front in the longitudinal direction. This arrangement allows for easy wiring of the optical fiber 45, as described below.

[0099] It is preferable that the rear end of the camera module 30 and the first light source unit 41, which is located closest to the tip end 12 among the light sources 40, are close to each other. In this embodiment, of the light source 40 located closest to the tip end 12, a portion of the front surface on the tip end 12 side faces the rear end of the camera module 30 in the longitudinal direction. With such a structure, i.e., a structure in which a portion of the light source 40 overlaps the camera module 30 when viewed from the front in the longitudinal direction as shown in FIG. 4, the camera head 10 can be made even more compact.

[0100] The optical fiber 45 is disposed radially outward from the outer surface of the camera module 30. In this embodiment, the optical fiber 45 is disposed between the flat portion of the camera module 30 and the inner peripheral surface of the housing 20. The optical fiber 45 guides the light emitted from each light source 40 to the vicinity of the tip 12 so that the light is irradiated onto the imaging area. It may also be said that the optical fiber 45 guides the light to the vicinity of the tip 12. It may also be said that the optical fiber 45 guides the light to the vicinity of the tip 12. The vicinity of the tip 12 may include the tip 12.

[0101] In this embodiment, the optical fiber 45 has four optical fibers corresponding to the respective light sources 40. Note that for one light source 40, two or more elements such as optical fibers may be provided to guide light so that the light is emitted from different positions in the radial or circumferential direction.

[0102] In this embodiment, the four optical fibers of the optical fiber 45 are arranged around the camera module 30 so as to be spaced apart from each other in the circumferential direction and lined up in the circumferential direction, as shown in Fig. 5. The optical fibers are lined up at approximately equal intervals in the circumferential direction. That is, the four optical fibers are lined up at approximately 90-degree intervals in the circumferential direction.

[0103] Here, each optical fiber is arranged along the flat portion of camera module 30. In the present embodiment, one optical fiber is arranged in each of the four spaces generated between each of the four flat portions and the inner peripheral surface of housing 20. By arranging the optical fibers in this manner, each component of camera head 10 can be housed in housing 20 with a smaller diameter, and the diameter of camera head 10 can be made even smaller.

[0104] In this embodiment, guide 25 is disposed inside housing 20 near tip portion 12. Guide 25 is disposed in a position aligned with camera module 30 in the longitudinal direction. As shown in the figure, guide 25 is formed so as to fill the inside of housing 20 except for the camera module 30 and optical fiber 45. That is, guide 25 has camera guide portion 26, which is a gap provided approximately in the center and has approximately the same shape as the cross section of camera module 30, and fiber guide portions 27, which are gaps formed at four locations where each of optical fibers 45 should pass. The side peripheral surface of guide 25 is formed in approximately the same shape as the inner wall surface of first cylindrical portion 21, so that guide 25 can be housed within first cylindrical portion 21.

[0105] The provision of such guides 25 makes it possible to position the camera module 30 and each optical fiber 45 in the radial direction, thereby facilitating the manufacture of the camera head 10 and improving the durability of the camera head 10.

[0106] In this embodiment, the filter 50 is disposed near the tip 12 of the camera head 10. Light incident on the camera head 10 and light emitted from the camera head 10 pass through the filter 50. The filter 50 has a first transmitting section 51 for illumination and a second transmitting section 52 for imaging provided on a transparent substrate 53. That is, the first transmitting section 51 is disposed on the substrate 53 and transmits light emitted from the camera head 10. The second transmitting section 52 is disposed on the substrate 53 and transmits light incident on the camera head 10.

[0107] In this embodiment, camera head 10 is configured to be usable for bioimaging technology, for example, by irradiating an imaging area with excitation light of a specific wavelength to excite a fluorescent substance and capturing the emitted fluorescence. To enable camera head 10 to be used for such applications, second transmitting section 52 is disposed at the tip side of camera module 30, and first transmitting section 51 is disposed at the tip side of optical fiber 45.

[0108] The first transmitting section 51 is, for example, an excitation light filter. The first transmitting section 51 passes only light within a specific wavelength range from the light guided by the optical fiber 45 and irradiates the imaging area with this light. This light acts on fluorescent substances or fluorescent markers within tissue or the like in the imaging area, exciting them. The second transmitting section 52 is, for example, a fluorescence filter. The second transmitting section 52 is configured to pass only fluorescence within a specific wavelength range different from the excitation light, and allows only a specific fluorescence signal generated after excitation to be incident on the light receiving section 32 of the camera module 30 with high precision.

[0109] The second transmitting section 52 is fixed to the camera module 30 so as to cover the front of the light receiving section 32. The first transmitting section 51 is arranged in front of the optical fiber 45 so as to have a shape that closes the gap between the second transmitting section 52 and the inner peripheral surface of the housing 20. That is, in this embodiment, the tip section 12 of the camera head 10 is sealed by the filter 50. Note that the rear end section of the camera head 10 is sealed using, for example, a bonding material or the like, but is not limited to this.

[0110] The filter 50 is not limited to those having the above-described characteristics. Filters having properties appropriate for the respective applications may be used. Furthermore, one or both of the first transmitting portion 51 and the second transmitting portion 52 may not be used. In this case, a filter for protection purposes may be provided at the tip portion 12, or no optical element may be provided in addition to the camera module 30 and the optical fiber 45. The filter 50 is a so-called optical filter, but it does not have to be so.

[0111] In this embodiment, the emission portion 46 near the tip 12 of each optical fiber 45 has an inclined portion 47 formed so as to be inclined with respect to the longitudinal direction. The inclined portion 47 is the end face of the tip 12 of the optical fiber 45. It can be said that the tip of each optical fiber 45 has an end face that is not approximately perpendicular to the direction in which the optical fiber 45 extends, but is cut at an angle. By providing the inclined portion 47 in each optical fiber 45 in this manner, the emission portion 46 of each optical fiber 45 is configured to be able to emit at least a portion of the light guided from the light source 40 in a direction different from the longitudinal direction.

[0112] In this embodiment, in particular, each inclined portion 47 is formed so as to be inclined so as to move away from the tip portion 12 in the longitudinal direction toward the rear as it approaches the outer side of the center of the tip portion 12 in a direction perpendicular to the longitudinal direction. In other words, each inclined portion 47 has a surface that is inclined so as to move away from the tip portion 12 in the longitudinal direction as it approaches the inner circumferential surface of the housing 20 in the radial direction. It can be said that each inclined portion 47 is inclined so that the center of the camera head 10 approaches the tip portion 12. 。

[0113] Incidentally, the emission section 46 may not have the inclined section 47, but may have an optical member configured to be able to diffuse light, or may be formed in a shape different from the inclined surface, so that the light guided from the light source 40 can be emitted in a direction different from the main longitudinal direction. Also, the emission section 46 may not have a particular emission section 46, and the light may be emitted from the end face of the optical fiber 45 mainly along the main longitudinal direction.

[0114] Next, the configurations of the joint portion 70 and the optical element 80 will be described.

[0115] In this embodiment, the joint unit 70 has an attachment portion 71 to which the camera head 10 is attached, and a fixing portion 72 to which the optical element 80 is attached. As shown in FIG. 7, in this embodiment, the joint unit 70 is formed in a substantially cubic shape, but is not limited to this. For example, the joint unit 70 may be spherical or cylindrical. The joint unit 70 is made of, for example, metal, but may also be made of other materials, such as engineering plastic.

[0116] The mounting portion 71 is a portion formed so as to be recessed from the side opposite to the side where the optical element 80 is attached in the longitudinal direction. The mounting portion 71 can also be said to be a hole capable of accommodating the tip portion 12 of the camera head 10. An internal thread that engages with the external thread 13 of the camera head 10 is formed on the inner peripheral surface of the mounting portion 71. In other words, the external thread 13 is screwed into the mounting portion 71, allowing the tip portion 12 of the camera head 10 to be attached.

[0117] The joint portion 70 is configured so that a fixing screw 78 can be screwed radially inward from the side surface. The tip of the fixing screw 78 can protrude from the inner circumferential surface of the mounting portion 71. The camera head 10 can be fixed to the joint portion 70 by screwing the fixing screw 78 so that the fixing screw 78 comes into contact with the vicinity of the tip portion 12 of the camera head 10 that is screwed into the mounting portion 71. The type of fixing screw 78 is not important; for example, a headless set screw or a screw with a knob may be used. Alternatively, the fixing screw 78 may not be used. In this case, the mounting portion 71 and the male screw 13 may be formed so that a certain amount of torque is required to rotate them relative to each other, or an anti-loosening agent or the like may be interposed between the threads.

[0118] The fixing portion 72 is a portion formed to be recessed in the longitudinal direction so as to open toward the tip of the photographing unit 1. The fixing portion 72 can be said to be a hole portion formed so that a fixing member 90 can be fitted therein, as will be described later. A hole 76 is formed on the inner peripheral surface of the fixing portion 72 so that adhesive 77 can be poured from the outer periphery of the joint portion 70.

[0119] In this embodiment, fixing portion 72 is provided with fixing surface 74 that can determine the position of fixing member 90 in the longitudinal direction. In this embodiment, fixing surface 74 is a surface that is perpendicular to the longitudinal direction. A hole that penetrates mounting portion 71 is provided in the center of fixing surface 74.

[0120] The female thread of the mounting portion 71 and the fixing portion 72 (including the hole formed in the center of the fixing surface 74) are formed coaxially. This allows the gradient index lens 81, to which the fixing member 90 is attached and fixed to the fixing portion 72, and the camera head 10, to be attached to the mounting portion 71, to be aligned coaxially. Therefore, the photographing unit 1 can be easily assembled so as to be able to appropriately emit light and capture images.

[0121] The optical element 80 is configured by attaching a fixing member 90 to a gradient index lens 81. In this embodiment, the fixing member 90 is attached to the end of the gradient index lens 81 that is closer to the camera head 10 in the longitudinal direction, i.e., the end of the optical element 80. The gradient index lens 81 and the fixing member 90 can be fixed by a method such as, but not limited to, adhesive bonding.

[0122] FIG. 8 is a side view of the fixing member 90 of the camera head 10. FIG.

[0123] 8, the fixing member 90 is cylindrical and has a through-hole in the center into which the gradient index lens 81 can be inserted. A groove 92 is formed around the entire circumference of the outer periphery 91 of the fixing member 90, recessed radially inward from the outer periphery 91. A protrusion 95 having a smaller outer diameter than the outer periphery 91 is formed in the axial direction of the fixing member 90. A contact surface 94 is formed between the outer periphery 91 and the protrusion 95, perpendicular to the axial direction.

[0124] The outer peripheral portion 91 or the protruding portion 95 and the through-hole into which the gradient index lens 81 can be inserted are formed coaxially, thereby allowing the gradient index lens 81 and the camera head 10 to be positioned coaxially with high precision.

[0125] As shown in FIG. 6 , the optical element 80 is attached to the joint portion 70 with the contact surface 94 of the fixing member 90 in contact with a portion of the joint portion 70 and the outer periphery 91 facing a portion of the joint portion 70. The fixing member 90 is positioned so as to be fitted inside the fixing portion 72. The protrusion 95 of the fixing member 90 is fitted into a hole formed in the center of the fixing surface 74 and penetrating the mounting portion 71. In this state, the fixing member 90 is fixed to the joint portion 70 by, for example, adhesive or other methods. For example, the fixing member 90 can be fixed to the joint portion 70 by filling the gap between the fixing portion 72 and the outer periphery 91 of the fixing member 90 with adhesive 77. Note that the adhesive 77 can be filled through the hole 76, as described below, which makes it easy to fix the fixing member 90 to the joint portion 70. The adhesive 77 can be filled between the groove 92 of the fixing member 90 and the inner circumferential surface of the fixing portion 72, so that the fixing member 90 can be reliably fixed to the joint portion .

[0126] Here, the inner diameter of the inner peripheral surface of fixing portion 72 and the outer diameter of outer peripheral portion 91 of fixing member 90 are set to be approximately the same dimension. The inner diameter of the hole in the center of fixing surface 74 and the outer diameter of protrusion 95 may also be set to be approximately the same dimension. This allows gradient index lens 81 and camera head 10 to be positioned coaxially with high precision.

[0127] In this embodiment, the contact surface 94 of the fixing member 90 faces the fixing surface 74 of the fixing part 72. The fixing member 90 is fixed to the joint part 70 with the contact surface 94 in contact with the fixing surface 74. Therefore, assembly can be performed reliably so that the fixing member 90 is positioned at a predetermined position relative to the joint part 70 in the longitudinal direction.

[0128] Here, it is desirable that the dimension of the protrusion 95 in the axial direction, i.e., the dimension from the contact surface 94 to the end of the protrusion 95 in the axial direction, be controlled with relatively high precision so as to be a predetermined dimension. As a result, when fixing the gradient index lens 81 to the fixing member 90, the position of the lens rear end 82 relative to the joint part 70 can be set with high precision by controlling the positional relationship between the end of the protrusion 95 and the lens rear end 82, which is relatively easy to align. Even when manufacturing a plurality of assemblies of joint part 70 and optical element 80, the positional error of the lens rear end 82 can be easily reduced.

[0129] A stopper 98 is attached to the optical element 80. The stopper 98 is fixed to the gradient index lens 81 at a predetermined position from the tip of the photographing unit 1 by, for example, adhesive or other methods. In this embodiment, the stopper 98 is provided to position the photographing unit 1 relative to the subject organism. Note that the stopper 98 does not necessarily have to be provided.

[0130] In the present embodiment, the stopper 98 has the same shape as the fixing member 90. That is, the same part can be used as both the fixing member 90 and the stopper 98. However, this is not limiting, and the stopper 98 may have any shape.

[0131] In this embodiment, the filter 50 is configured, for example, as follows.

[0132] FIG. 9 is a diagram illustrating the configuration of the filter 50 of the camera head 10. As shown in FIG.

[0133] In the present embodiment, the filter 50 is formed in a disk shape so as to close the opening at the tip portion 12 of the housing 20. A second transmitting portion 52 is arranged in the center of the filter 50 so as to cover the tip side of the camera module 30. Furthermore, a first transmitting portion 51 is arranged around the second transmitting portion 52 so as to cover the tip of each optical fiber 45. Note that the properties of the first transmitting portions 51 corresponding to the first light source unit 41 and the second light source unit 42 may be different.

[0134] By using the filter 50 in which the first transmitting portion 51 and the second transmitting portion 52 are formed on the same substrate 53 as a single component, the camera head 10 can be easily assembled.

[0135] Here, the camera head 10 can be configured to be extremely small, for example, with an outer diameter of about 1 to 2 millimeters. The filter 50 used in such a small camera head 10 is also small. The small filter 50 can be manufactured, for example, as follows.

[0136] FIG. 10 is a diagram illustrating an example of a method for manufacturing the filter 50. In FIG.

[0137] (Step S11) First, a member having the first transmitting portion 51 (herein referred to as the first member 51b) and a member having the second transmitting portion 52 (herein referred to as the second member 52b) are prepared. Also, a transparent substrate 53 that is sufficiently larger than the size of the filter 50 is prepared.

[0138] The first member 51b and the second member 52b may be large enough to be easily handled during manufacturing. The first member 51b and the second member 52b can be easily prepared by, for example, coating a transparent plate or film, or by vapor deposition.

[0139] (Step S12) Next, the first member 51b and the second member 52b are each partially disposed on the transparent substrate 53. In this case, for example, the first member 51b and the second member 52b may be disposed so as to match the positional relationship between the first transmission section 51 and the second transmission section 52 in the finished filter 50 (shown by the two-dot chain line in the drawing).

[0140] (Step S13) Then, the substrate 53 on which the first member 51b and the second member 52b are arranged is cut out into the shape of the filter 50.

[0141] Thereafter, the cut filter 50 is placed near the tip 12 of the camera head 10, thereby completing the manufacture of the camera head 10.

[0142] In this way, the small filter 50 in which the first transmission portion 51 and the second transmission portion 52 are partitioned can be manufactured easily and with a high yield.

[0143] The method for manufacturing the filter 50 is not limited to this. For example, layers corresponding to the first transmission portion 51 and the second transmission portion 52 may be partially disposed at predetermined positions on a substrate 53 such as glass by a method such as vapor deposition. In this case, to separate the regions where each layer is to be formed in the manufacturing process of the filter 50, for example, photolithography may be used to sequentially apply photoresist, expose the pattern, and perform an etching process, but the method is not limited to this.

[0144] Next, a method for manufacturing the photographing unit 1 according to this embodiment will be described.

[0145] Fig. 11 is a first diagram illustrating a manufacturing method of the photographing unit 1. Fig. 12 is a second diagram illustrating a manufacturing method of the photographing unit 1.

[0146] First, the optical element 80 is assembled. That is, the fixing member 90 is fixed to the end of the gradient index lens 81 (step S21). At this time, it is desirable to align the position of the lens rear end 82 with the position of the end of the protrusion 95 of the fixing member 90, for example, so that the fixing member 90 and the gradient index lens 81 have a predetermined positional relationship (step S22).

[0147] Next, the optical element 80 is fixed to the joint part 70. That is, the optical element 80 is assembled to the joint part 70 so that the fixing member 90 fits into the fixing part 72 (step S23). Then, with the outer periphery 91 of the fixing member 90 inserted inside the joint part 70 and the fixing surface 74 and the contact surface 94 in contact, adhesive 77 is poured between the joint part 70 and the groove part 92 through the hole 76 provided in the joint part 70 (step S24). This fixes the fixing member 90 to the joint part 70.

[0148] Next, the camera head 10 is fixed to the joint part 70. That is, the tip part 12 of the camera head 10 is screwed into the attachment part 71 of the joint part 70 (step S25). At this time, the position of the camera head 10 with respect to the joint part 70 can be adjusted so that a desired light emission state or light incidence state is obtained between the camera head 10 and the optical element 80. Then, the position of the camera head 10 with respect to the joint part 70 is fixed at an appropriate position with the fixing screw 78 (step S26). This allows the camera head 10 to be attached to the joint part 70.

[0149] The positional relationship between the front end 12 of the camera head 10 and the rear end 82 of the lens is important for capturing a focused image and irradiating light appropriately. Because the camera head 10 and the joint unit 70 are connected by a screw, this positional relationship can be easily adjusted by rotating the camera head 10 around its axis relative to the joint unit 70. Furthermore, because the connection between the two is made by a screw, changes to the positional relationship can be controlled with relatively high precision according to the pitch of the screw. For example, even if the camera head 10 and the joint unit 70 are separated and then reassembled, the state before separation can be easily reproduced by assembling them with the same screw-in amount as before separation.

[0150] In this embodiment, in order to easily manage the amount of screwing, markings may be provided on at least one of the housing 20 and the joint part 70 of the camera head 10 to allow the amount of screwing to be checked or information on the amount of screwing to be recorded.

[0151] 12, markings 17 may be provided on a portion of the outer periphery of housing 20 in the circumferential direction. This makes it easier to accurately check how many turns camera head 10 has made relative to joint part 70 when screwing camera head 10 into joint part 70.

[0152] FIG. 13 is a view of the joint part 70 of the photographing unit 1 viewed from the rear end side in the longitudinal direction.

[0153] 13, for example, markings 18 may be provided in a row in the circumferential direction around the mounting portion 71 of the joint portion 70. By screwing the camera head 10 into the joint portion 70 while checking the positional relationship between these markings 18 and the markings 17 or distinctive portions on the camera head 10, it becomes easier to accurately check how many turns the camera head 10 has made relative to the joint portion 70.

[0154] The position and manner of marking are not limited to these.

[0155] Next, an example of use of the imaging system 1000 using the imaging unit 1 will be described.

[0156] FIG. 14 is a diagram illustrating an example of use of the imaging system 1000 according to this embodiment.

[0157] 14 shows an example of use in which the imaging system 1000 is used to acquire an image of the state of tissue in a test subject 900. Here, the test subject 900 is, for example, a rodent, specifically a mouse. In this example, the imaging system 1000 is used to observe activity at a specific location in the mouse's brain. For example, the tip of the imaging unit 1 is inserted close to the target location in the brain, and light for observation is emitted to the target location and an image of the target location is captured to obtain an image.

[0158] For such purposes, a small photographing unit 1 is used. For example, the photographing unit 1 is configured to have a small diameter of about 1 to 2 millimeters, is lightweight, and is configured using a thin gradient index lens 81 at the site to be inserted into the living body. By using such a small photographing unit 1, observation can be performed in a minimally invasive manner on the subject organism 900.

[0159] In addition, in this embodiment, the image acquisition device 500 is configured to be small and relatively lightweight, so that it can be held by the test subject organism 900.

[0160] By using such an imaging system 1000, observation can be performed with the tips of the three imaging units 1 embedded in a living organism, and with the image acquisition device 500 connected to the imaging units 1 via cables being held by the test subject organism 900, and imaging results can be obtained from the imaging units 1. Continuous observation can be performed in a minimally invasive manner to the test subject organism 900, without significantly interfering with the normal activities of the test subject organism 900. Therefore, it becomes possible to conduct experiments under conditions and in observation modes that would be difficult to perform using conventional large camera heads.

[0161] In the present embodiment, the imaging system 1000 can be used together with an external terminal device 600, but is not limited to this. The terminal device 600 is, for example, a so-called server device, but may also be a general personal computer, a smartphone, a tablet terminal, or a server device. When the image acquisition device 500 is configured to be capable of wireless communication, it is desirable that the terminal device 600 be configured to be able to send and receive information with the image acquisition device 500 by wireless communication. The image acquisition device 500 may have, for example, a detachable removable medium as an information storage unit, and may be configured to allow the terminal device 600 to acquire information via the removable medium.

[0162] In such a use example, the photographing unit 1 can be attached to the test subject organism 900 by, for example, the following attachment method.

[0163] Fig. 15 is a first diagram illustrating an example of a method for attaching the photographing unit 1 to a test subject organism, and Fig. 16 is a second diagram illustrating an example of a method for attaching the photographing unit 1 to a test subject organism.

[0164] (Step S51) First, the joint part 70 to which the optical element 80 is fixed is prepared. Then, the stopper 98 is fixed at a position a predetermined distance D5 rearward from the tip of the optical element 80. As will be described later, the predetermined distance D5 can be set so that the tip of the optical element 80 is located at a desired position (depth) when the stopper 98 is in a predetermined position with respect to the test subject organism 900.

[0165] (Step S52) Next, the optical element 80 is attached to the test subject organism 900 together with the joint portion 70. Here, the optical element 80 is attached to the test subject organism 900 so that the stopper 98 is positioned at a predetermined position relative to the test subject organism 900.

[0166] For example, consider a case where an observation target site 990 is present at a predetermined depth from the epidermis 910 of a test subject organism 900. In this case, a predetermined distance D5 from the tip of the optical element 80 to the stopper 98 is set according to the depth of the observation target site 990 from the epidermis 910, and the stopper 98 is fixed in place in advance. Then, by inserting the optical element 80 into the tissue of the test subject organism 900 so that the stopper 98 is close to the epidermis 910, the tip of the optical element 80 can be easily positioned at an appropriate position for capturing an image of the observation target site 990.

[0167] Furthermore, with the optical element 80 attached to the subject organism 900 in this manner, the stopper 98 can be fixed to the epidermis 910 and other parts with an adhesive (not shown) or the like to prevent the photographing unit 1 from falling off the subject organism 900.

[0168] (Step S53) Next, the camera head 10 is fixed to the joint unit 70. That is, similar to step S25 described above, the tip portion 12 of the camera head 10 is screwed into the attachment portion 71 of the joint unit 70. Then, the position of the camera head 10 with respect to the joint unit 70 is adjusted so that a desired light emission or incidence state is obtained between the camera head 10 and the optical element 80.

[0169] (Step S54) Then, similarly to step S26 described above, once the position of camera head 10 relative to joint part 70, i.e., the distance D6 between tip part 12 of camera head 10 and rear end part 82 of lens, is appropriate, the position of camera head 10 relative to joint part 70 is fixed with fixing screw 78. This allows the photographing unit 1 to be attached to test subject organism 900 so that observation is possible.

[0170] As described above, in this embodiment, the distance of the camera head to the optical element 80 can be adjusted with high precision, and the photographing unit 1 can be handled easily.

[0171] Because the camera head 10 and joint part 70 are connected by screws, they can be easily disassembled and readjusted, allowing for flexible adaptation to different observation conditions and environments. Furthermore, this structure allows the photographing unit 1 to be disassembled for cleaning and maintenance, ensuring long-term durability. For example, even if dirt accumulates on the sensor part of the camera head 10 or the surface of the optical element 80, observation accuracy can be maintained by quickly disassembling and cleaning.

[0172] Furthermore, the imaging unit 1 is configured so that the optical element 80, which is located near the observation target, and the camera head 10 can be separated. This allows for easy and reliable installation on the subject organism 900, etc. For example, even when the observation target is a small animal or requires observation inside a narrow body cavity, efficient and safe installation can be achieved by first placing the optical element 80 and then attaching the camera head 10. Depending on the observation method, the optical element 80 and joint 70 may be disposable, while the camera head 10 may be reusable, enabling multiple observations at low cost. Furthermore, this structure allows for flexible operation by simply replacing the optical element 80, adapting to different observation methods and conditions. For example, by replacing the optical element 80 corresponding to a different wavelength, different types of fluorescence observation can be performed with the same camera head 10. Furthermore, because the optical element 80 is replaceable, using an element specialized for a specific observation target can easily improve observation accuracy and introduce new observation techniques. Furthermore, by disposing of the optical element 80 after observation, hygiene risks can be reduced and safety can be improved, particularly in medical applications.

[0173] The inclined portion 47 is provided at the output portion 46 of each optical fiber 45, so that the light guided from the light source 40 of effective to It is possible to irradiate.

[0174] (Embodiment 2)

[0175] An overview of the second embodiment of the present invention will be described, focusing on the differences from the first embodiment described above. The second embodiment uses an imaging unit 201 having the same configuration as the first embodiment, except for the following: The present embodiment uses a guide member that is arranged near the rear end of the gradient index lens 81 and configured to direct a portion of the light emitted from the tip 12 of the camera head 210 to the side of the gradient index lens 81. A plurality of light sources 40 are arranged in series in the longitudinal direction. The camera head 210 uses a housing 220 having a substantially straight tube shape. Filters 250 are provided separately in the paths corresponding to each light source 40 and camera module 30.

[0176] FIG. 17 is a side cross-sectional view of an imaging unit 201 according to the second embodiment of the present invention.

[0177] As shown in FIG. 17, the photographing unit 201 includes a camera head 210, a joint portion 270, and an optical element 280.

[0178] The camera head 210 has a housing 220 that extends in the longitudinal direction and has a uniform outer diameter. A male screw 13 is formed on the tip end 12 side of the housing 220. This allows the camera head 210 to be attached to the attachment portion 71 of the joint portion 270.

[0179] In the camera head 210, four light sources 40 are housed so as to be aligned in a row in the longitudinal direction. That is, two first light source units 41 and two second light source units 42 are disposed at different positions behind the camera module 30. An optical fiber 45 is disposed from each light source 40 to the vicinity of the tip portion 12. By adopting such a layout of the light sources 40, a camera head 210 with a smaller diameter can be configured.

[0180] Here, in the second embodiment, the filter 50 is not provided, but four first filters 251 are provided between each light source 40 and the optical fiber 45, and a second filter 252 is provided so as to transmit light incident on the camera module 30. By providing this group of filters 250, it is possible to perform light irradiation and photography in the same way as in the first embodiment described above.

[0181] Each filter 250 can be cut out from a larger member, but the manufacturing method is not limited to this. Compared to constructing a small filter 50 having different types of transmission sections integrated together, the filters 250 can be prepared more easily.

[0182] Optical element 280 according to embodiment 2 does not have the fixing member 90 of optical element 80. Optical element 280 has gradient index lens 81 and guide member 285 provided near rear end 82 of the lens.

[0183] A through-hole is provided in the center of guide member 285 so that gradient index lens 81 passes through. Guide member 285 is attached to gradient index lens 81 so that rear end portion 82 of the lens is exposed from part of the rear end surface of guide member 285.

[0184] The outer peripheral surface of the guide member 285 is, for example, coaxial with the central axis of the gradient index lens 81, and is part of a conical surface having a generatrix that intersects with the central axis further forward than the lens rear end 82. That is, the guide member 285 has a side cross-sectional shape in which the radial dimension increases in the longitudinal direction toward the lens rear end 82. The guide member 285 is made of, for example, a transparent material used in optical elements, but is not limited to this.

[0185] The optical element 280 is fixed to the joint portion 270 such that the rear end of the guide member 285 and the lens rear end 82 are exposed to the attachment portion 71. That is, the optical element 280 is configured so that light emitted from the tip portion 12 of the camera head 210 also enters the guide member 285 from the rear end of the guide member 285. The light that enters the guide member 285 passes directly through the inside of the guide member 285 and enters the lens side surface 83, or is reflected inward by the outer circumferential surface of the guide member 285 and enters the lens side surface 83. That is, it can be said that the guide member 285 has a reflecting portion 287, which is the outer circumferential surface of the guide member 285. The reflecting portion 287 reflects light that enters from behind the guide member 285 radially inward at a position forward of the lens rear end 82 of the refractive index gradient lens 81 in the axial direction.

[0186] The reflecting portion 287 may be a portion configured to totally reflect most of the light incident from behind, or may be a portion that has been coated to form a mirror surface or the like so as to reflect more light.

[0187] By providing such a reflecting portion 287, light irradiated not only from the lens rear end portion 82 but also to a portion radially outward of the lens rear end portion 82 can be irradiated from the tip of the optical element 280 via the gradient index lens 81. This widens the range of light incidence, making it possible to appropriately utilize the light from the light source 40 while configuring the photographing unit 201 to be compact. In particular, since the reflecting portion 287 efficiently collects light onto the lens side surface 83, it is possible to improve the uniformity of the light irradiated onto the observation object, and to acquire a fine, clear image.

[0188] (others)

[0189] In the above-described embodiments, each component of the image acquisition device may be configured with dedicated hardware, or components that can be realized by software may be realized by executing a program. For example, each component may be realized by a program execution unit such as a CPU reading and executing a software program recorded on a recording medium such as a hard disk or semiconductor memory. During execution, the program execution unit may execute the program while accessing a storage unit or recording medium. The program may also be executed by being downloaded from a server or the like, or by being read from a predetermined recording medium (e.g., an optical disk, a magnetic disk, a semiconductor memory, etc.). This program may also be used as a program constituting a program product.

[0190] Furthermore, in the above embodiments, the transfer of information between components may be performed, for example, by one component outputting information and the other component receiving information if the two components transferring the information are physically different, or by moving from a processing phase corresponding to one component to a processing phase corresponding to the other component if the two components transferring the information are physically the same.

[0191] Furthermore, in the above-described embodiments, information related to the processing performed by each component, such as information accepted, acquired, selected, generated, transmitted, or received by each component, and information such as thresholds, formulas, and addresses used in processing by each component, may be temporarily or long-term stored in a recording medium (not shown), even if not explicitly stated in the above description. Furthermore, the storage of information in the recording medium (not shown) may be performed by each component or a storage unit (not shown). Furthermore, the reading of information from the recording medium (not shown) may be performed by each component or a reading unit (not shown).

[0192] The present invention is not limited to the above-described embodiment, and various modifications are possible, and these modifications are also included within the scope of the present invention.

[0193] The components of the above-described embodiments and variations may be combined as appropriate to form an embodiment. For example, each component of the above-described embodiments and variations may be replaced or combined with a component of another variation, etc., as appropriate. Furthermore, some components or functions of the above-described embodiments and variations may be omitted.

[0194] The image acquisition device may have its own display and be configured to be able to display captured images. The image acquisition device may be, for example, a personal computer itself.

[0195] Alternatively, one first light source unit and one second light source unit may be arranged at approximately the same position in the longitudinal direction, with another first light source unit and another second light source unit arranged behind them. Alternatively, the first light source unit may be located at the rear, and the second light source unit may be located at the front. Alternatively, it is sufficient that one of the first light source unit and the second light source unit is located in front of or behind the other.

[0196] The light source does not have to be housed within the photographing unit. For example, the light source may be provided in an image acquisition device or the like, and light guided to the photographing unit via an optical fiber or the like may be emitted from the photographing unit. Furthermore, the photographing unit does not have to be configured to be able to emit light to a target area.

[0197] The camera head described in the above embodiment may be used alone, i.e., attached to a test subject organism without attaching an optical element to the tip. In other words, the camera head can be used alone or as a photographing unit with a joint and an optical element attached. Therefore, the camera head is highly versatile and can be used for a variety of purposes. In this case, it is preferable that the tip of the camera head is covered with a filter or other optical member to ensure liquid-tightness. [Industrial Applicability]

[0198] As described above, the photographing unit according to the present invention is easy to use and useful. [Explanation of symbols]

[0199] 1,201 filming units 10,210 camera head 12 Tip 13 Male thread 20,220 cabinets 21 First cylinder part 22 Second cylinder part 23 Insulation section 25 Guide 30 Camera Module 40 light source 41 First light source section 42 Second light source section 45 Optical Fiber 46 Exit section 47 Slope 50 filters 51 First transmission section 52 Second transmission section 53 Circuit Board 70 Joint 71 Mounting part 76 holes 77 Adhesive 78 Fixing screw 80,280 optical elements 81 Gradient index lens 82 Rear end of lens 83 Lens side 90 Fixing member 91 Outer periphery 92 Groove 94 Contact surface 98 Stopper 251 First Filter 252 Second Filter 285 Guide members 287 Reflector

Claims

1. an optical element that is a gradient index lens extending in a longitudinal direction and adjusting a path of light between the optical element and an observation object; a joint portion that can be fixed to the optical element; a camera head including a camera module, a light source disposed behind the camera module, a tip portion disposed near the optical element, into which light from the optical element is incident and which emits light to the optical element, and an optical fiber extending from the light source to the vicinity of the tip portion; the gradient index lens, the joint unit, and the camera head are aligned in the longitudinal direction of the gradient index lens, A male thread is formed around the periphery of the tip portion, the joint portion has an attachment portion into which the male screw is screwed, the tip portion is disposed inside the joint portion, the male screw and the mounting portion constitute an adjustment structure that adjusts the positional relationship between the tip portion and the optical element in the longitudinal direction of the gradient index lens, an end face of the tip end of the optical fiber is provided with an inclined portion formed so as to incline away from the tip end in the longitudinal direction of the refractive index gradient lens as it approaches the outside from a central portion of the tip end in a direction perpendicular to the longitudinal direction of the refractive index gradient lens, the inclined portion being configured to emit light guided from the light source from the inclined portion in a direction different from the longitudinal direction of the refractive index gradient lens; The photographing unit is configured so that the adjustment structure can adjust the positional relationship between the tip portion and the optical element in the longitudinal direction of the refractive index gradient lens so that a desired light emission or incidence state can be obtained between the tip portion and the optical element.

2. the camera head has a housing having a portion where the male screw is formed, Each part of the camera head is housed inside the housing, The housing includes: a first cylindrical portion which is a cylindrically formed portion located near the tip portion; a second cylindrical portion located on the side closer to the rear end portion opposite the front end portion and having at least the light source disposed therein; The photographing unit according to claim 1 , further comprising: a heat insulating portion disposed between the first cylindrical portion and the second cylindrical portion, the heat insulating portion being made of a material having a lower thermal conductivity than the second cylindrical portion.

3. The photographing unit according to claim 1 , wherein the camera head has a guide disposed near the tip end for positioning the camera module and the optical fiber in a radial direction.

4. The camera head a first filter disposed between the light source and the optical fiber; The photographing unit according to claim 1 , further comprising: a second filter arranged to transmit light incident on the camera module.

5. the camera head has a filter disposed near the tip portion and transmitting light incident on the camera head and light emitted from the camera head; The filter is A transparent substrate and a first transmission portion disposed on the substrate and transmitting the emitted light; The photographing unit according to claim 1 , further comprising: a second transmission portion disposed on the substrate and transmitting incident light.

6. the optical element extends in a longitudinal direction and has a rear end and a side surface; 2. The photographing unit according to claim 1, further comprising a guide member arranged near the rear end of the optical element and configured to direct a portion of the light emitted from the front end of the camera head to the side of the optical element.

7. The photographing unit according to claim 6 , wherein the guide member has a reflecting portion in a position forward of the rear end portion of the optical element that reflects light incident from behind toward an inner side where the side surface of the optical element is located.

8. the optical element is a member extending in a longitudinal direction, a fixing member attached to an end of the optical element that is closer to the camera head in the longitudinal direction; A groove is formed on the outer periphery of the fixing member, the optical element is attached to the joint part in a state in which a contact surface of the fixing member that is perpendicular to the longitudinal direction and that can position the optical element in the longitudinal direction is in contact with a part of the joint part, and the outer periphery of the fixing member faces a part of the joint part, The photographing unit according to claim 1 , wherein an adhesive is disposed between the groove portion and the joint portion.

9. The photographing unit according to claim 1, wherein the joint portion is provided with a fixing means that can be positioned so as to fix the camera head to the joint portion by contacting the vicinity of the tip of the camera head screwed into the mounting portion.

10. A camera head that can be used in the photography unit according to claim 1, The housing and a camera module provided near a tip end of the housing; A camera head, wherein the male screw that can be screwed into the attachment portion of the joint portion is formed around the periphery of the tip portion of the housing.

11. A method for attaching the photographing unit according to any one of claims 1 to 8 to a non-human subject, comprising: fixing the joint portion to the optical element; attaching the optical element to a non-human subject; a step of screwing the tip of the camera head into the mounting portion of the joint portion to mount the camera head on the joint portion.

12. a step of fixing a stopper at a position spaced a predetermined distance rearward from the tip of the optical element; 12. The method for attaching an imaging unit according to claim 11, wherein the step of attaching the optical element to the non-human subject organism comprises attaching the optical element to the non-human subject organism so that the stopper is positioned at a predetermined position relative to the non-human subject organism.

13. A fixing member is attached to an end of the optical element, A groove is formed on the outer periphery of the fixing member, 12. The method for attaching a photographing unit according to claim 11, wherein the step of fixing the joint portion includes injecting adhesive between the joint portion and the groove portion through a hole provided in the joint portion while the outer periphery of the fixing member is inserted inside the joint portion.

14. 12. The method for attaching a photographing unit according to claim 11, wherein the step of attaching the camera head to the joint portion includes adjusting the position of the camera head relative to the joint portion so as to obtain a desired light emission or incidence state between the camera head and the optical element, and fixing the position of the camera head relative to the joint portion with a fixing means.

Images