Method for mounting the shooting unit, camera head, and shooting unit.

Abstract

There is a need for an easy-to-use shooting unit. [Solution] The shooting unit 1 comprises an optical element 80, for example, a refractive index distribution type lens; a joint part 70 that can be fixed to the optical element 80; and a camera head 10 located on the side closer to the optical element 80, into which light from the optical element 80 is incident and which emits light to the optical element 80. A male screw 13 is formed around the tip part 12. The joint part 70 has a mounting part 71 into which the male screw 13 is screwed. The tip part 12 is located inside the joint part 70. The shooting unit 1 allows for high-precision adjustment of the distance of the camera head to the refractive index distribution type lens.

Description

Technical Field

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

Background Art

[0002] Conventionally, various forms of camera heads and photographing units using the same have been used in, for example, endoscopes for living bodies and industrial endoscopes.

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

[0004] Further, for example, Patent Document 2 below describes a structure of an imaging unit including 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] Further, for example, Patent Documents 3 to 5 below describe configurations of photographing units using a gradient index lens (GRIN lens).

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

[0007] Incidentally, in imaging units composed of multiple components, such as a camera head and optical elements for observing objects, it is important to make them easier to handle. For example, in an imaging unit having a camera head and a refractive index distribution lens attached to its front, the part that attaches the lens to the camera head needs to be attached with high precision in order to detect light from the lens, and it is desirable that it be easy to attach.

[0008] This invention has been made in view of these points, and aims to provide an easily handleable imaging unit, a camera head, a method for manufacturing a camera head, and a method for mounting an imaging unit. [Means for solving the problem]

[0009] The imaging unit of the first invention comprises an optical element, a joint portion that can be fixed to the optical element, and a camera head located on the side closer to the optical element, into which light from the optical element enters and which emits light to the optical element, wherein a male screw is formed around the tip, the joint portion has a mounting portion into which the male screw is screwed, and the tip portion is located inside the joint portion.

[0010] This configuration allows for high-precision adjustment of the distance of the camera head to the optical elements, and makes the shooting unit easy to handle.

[0011] Furthermore, the imaging unit of the second invention, compared to the first invention, has an optical element which is a refractive index distribution type lens that extends in the longitudinal direction and adjusts the path of light with respect to the object to be observed, and the camera head has a camera module provided near the tip, a light source positioned 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 output section configured to emit at least a portion of the light guided from the light source in a direction different from the longitudinal direction of the refractive index distribution type lens.

[0012] With this configuration, light from the light source can be efficiently emitted towards the object to be observed via a refractive index distribution lens.

[0013] Furthermore, the imaging unit of this third invention differs from the second invention in that a refractive index distribution lens, a joint part, and a camera head are arranged in the longitudinal direction of the refractive index distribution lens, and the output part is an inclined part which is the end face of the tip of an optical fiber formed to be inclined with respect to the longitudinal direction of the refractive index distribution lens, and the inclined part is formed to be inclined so as it approaches the outer part of the tip in a direction perpendicular to the longitudinal direction of the refractive index distribution lens, it moves away from the tip in the longitudinal direction of the refractive index distribution lens.

[0014] This configuration allows light from a light source to be more efficiently emitted towards the object being observed via a refractive index distribution lens.

[0015] Furthermore, the imaging unit of the fourth invention, compared to the second invention, has a camera head having a housing with a portion where a male screw is formed, and each part of the camera head is housed inside the housing, and the housing is an imaging unit that includes a first cylindrical portion which is a cylindrical portion located near the tip, a second cylindrical portion which is a cylindrical portion located near the rear end opposite to the tip and in which at least a light source is arranged on the 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] With such a configuration, it is possible to make it difficult for the heat emitted from the light source to be transmitted to the tip of the camera head, and it is possible to prevent the heat from affecting the observation object.

[0017] In addition, the imaging unit of the fifth invention, with respect to the second invention, is an imaging unit in which the camera head is disposed near the tip and has a guide for positioning the position of the camera module and the position of the optical fiber (in the radial direction).

[0018] With such a configuration, the camera head can be easily assembled by positioning the positions of the camera module and the optical fiber so that they are in ideal positions.

[0019] In addition, the imaging unit of the sixth invention, with respect to the second invention, is an imaging unit in which the camera head has a first filter disposed between the light source and the optical fiber and a second filter disposed so that the light incident on the camera module passes through.

[0020] With such a configuration, the structure of the camera head having two types of filters can be flexibly designed.

[0021] In addition, the imaging unit of the seventh invention, with respect to the first invention, is an imaging unit in which the camera head has a filter through which the light incident on the camera head and the light emitted from the camera head pass. The filter has a transparent substrate, a first transmission portion disposed on the substrate through which the emitted light passes, and a second transmission portion disposed on the substrate through which the incident light passes.

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

[0023] Further, in the imaging unit of the eighth invention, with respect to the first invention, the optical element extends in the longitudinal direction, has a rear end portion and a side surface, and is disposed near the rear end portion of the optical element. The imaging unit includes a guide member configured to cause a part of the light emitted from the tip of the camera head to enter the side surface of the optical element.

[0024] With such a configuration, the light from the light source can be efficiently made to enter the optical element.

[0025] Further, in the imaging unit of the ninth invention, with respect to the eighth invention, the guide member has a reflection portion that reflects the light incident from the rear toward the inside where the side surface of the optical element is located at a position in front of the rear end portion of the optical element.

[0026] With such a configuration, the light from the light source can be efficiently made to enter the optical element.

[0027] [[ID=十六]]Further, in the imaging unit of the tenth invention, with respect to the first invention, the optical element is a member that extends in the longitudinal direction, and includes a fixing member attached to an end portion of the optical element closer to the camera head in the longitudinal direction. A groove portion is formed on the outer peripheral portion of the fixing member. The optical element is attached to the joint portion in a state where a contact surface of the fixing member in the longitudinal direction contacts a part of the joint portion and the outer peripheral portion faces a part of the joint portion, and an adhesive is disposed between the groove portion and the joint portion.

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

[0029] Further, the camera head of the eleventh invention is a camera head that can be used in the imaging unit according to the first invention, and includes a housing and a camera module provided near the tip of the housing. A male screw that can be screwed into the attachment portion of the joint portion is formed around the tip of the housing.

[0030] This configuration provides a camera head that allows for easy attachment and use of optical elements.

[0031] Furthermore, the method for manufacturing a camera head of the twelfth invention comprises a male screw that can be screwed into the joint of a shooting unit and a filter positioned near the tip to which the joint is attached, wherein light transmitted through a first transparent portion in a part of the filter is emitted toward the joint, and light incident from the joint is transmitted through a second transparent portion in a part of the filter, and the method for manufacturing a camera head includes the steps of: preparing a first member having a first transparent portion; preparing a second member having a second transparent portion; partially arranging the first member and the second member on a transparent substrate; cutting out the substrate on which the first member and the second member are arranged into the shape of a filter; and arranging the cut-out filter near the tip.

[0032] This configuration allows for the easy and reliable manufacture of a camera head equipped with a filter having two types of transmission sections.

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

[0034] This configuration allows for easy placement of optical elements in appropriate positions, enabling observation using a camera head.

[0035] Furthermore, the method for attaching the imaging unit of the fourteenth invention includes, compared to the thirteenth invention, a step of fixing a stopper at a predetermined distance rearward from the tip of the optical element, and the step of attaching the optical element to the test organism is to attach the optical element to the test organism in such a way that the stopper is positioned at a predetermined position relative to the test organism.

[0036] This configuration allows optical elements to be easily positioned in the appropriate locations.

[0037] Furthermore, the method for mounting the imaging unit of the fifteenth invention is a method for mounting the imaging unit in which a fixing member is attached to the end of the optical element, a groove is formed on the outer circumference of the fixing member, and the step of fixing the joint portion includes putting adhesive between the joint portion and the groove through a hole provided in the joint portion while the outer circumference of the fixing member is inserted inside the joint portion.

[0038] This configuration allows the joint to be securely fixed to the optical element.

[0039] Furthermore, the mounting method for the imaging unit of the sixteenth invention, compared to the thirteenth invention, is a mounting method for the imaging unit in which 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 that a desired light emission or incidence state can be obtained in relation to the optical element, and fixing the position of the camera head relative to the joint portion with a fixing means.

[0040] This configuration allows for easy placement of optical elements in appropriate positions, enabling reliable observation using a camera head. [Effects of the Invention]

[0041] According to the present invention, the imaging unit can be made easy to handle. [Brief explanation of the drawing]

[0042] [Figure 1] This figure illustrates the configuration of an imaging system according to one embodiment of the present invention. [Figure 2] Block diagram of the imaging system [Figure 3] Side cross-sectional view of the same imaging unit [Figure 4] Cross-sectional view along line AA in Figure 3 [Figure 5] Cross-sectional view of the CC line in Figure 3. [Figure 6] A side cross-sectional view showing an enlarged portion of the joint area of ​​the same imaging unit. [Figure 7] This is a view of the same imaging unit from the front end in the longitudinal direction. [Figure 8] Side view of the fixing component for the camera head. [Figure 9] This diagram illustrates the filter configuration of the camera head. [Figure 10] A diagram illustrating an example of the manufacturing method of the filter. [Figure 11] Figure 1 illustrates the manufacturing method of the imaging unit. [Figure 12] The second diagram illustrates the manufacturing method of the imaging unit. [Figure 13] This diagram shows the joint section of the same imaging unit viewed from the rear end in the longitudinal direction. [Figure 14] A diagram illustrating an example of how to use the imaging system according to this embodiment. [Figure 15] Figure 1 illustrates an example of how to attach the imaging unit to the organism being tested. [Figure 16] The second diagram illustrates an example of how to attach the imaging unit to the organism being tested. [Figure 17] Side cross-sectional view of the imaging unit according to Embodiment 2 of the present invention [Modes for carrying out the invention]

[0043] The following describes embodiments of the imaging unit and imaging systems using it with reference to the drawings. Note that components denoted by the same reference numerals in these embodiments are generally configured in a similar manner, and therefore, further explanation may be omitted.

[0044] In the following explanation, the direction perpendicular to the longitudinal direction of the tubular camera head may be 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 may be referred to as the circumferential direction. Also, in the following, the direction toward the tip in the longitudinal direction may be referred to as "front," and the opposite direction as "rear." For example, in this way, a certain direction may be indicated to explain the shape and positional relationship of each part, but the indication of direction is merely for the convenience of explanation and does not limit the orientation or posture of each device, etc., when in use according to the present invention. Furthermore, expressions indicating direction, or expressions indicating states such as horizontal, vertical, orthogonal, only indicate that they can be understood in a general sense, and should not necessarily be interpreted strictly according to those expressions.

[0045] (Embodiment 1)

[0046] The outline of Embodiment 1 is as follows. In this embodiment, the imaging unit has a camera head, a joint part attached to its tip, and an optical element that can be fixed to the joint part. The joint part is configured to be screwable onto the tip of the camera head. For example, a refractive index distributed lens can be used as the optical element.

[0047] The camera head may have a camera module located near the tip, a light source behind it, and an optical fiber extending from the light source to near the tip. The tip of the optical fiber may be inclined, and can be configured to allow light to enter appropriately using optical elements. The camera head may also be provided with a filter that allows light from the light source to pass through and light incident on the camera module to pass through. The filter may be positioned between the light source and the optical fiber, and at a position through which light incident on the camera module passes. Furthermore, the filter may be located near the tip and have a transparent portion that allows light emitted onto the substrate to pass through and a transparent portion that allows incident light to pass through.

[0048] To prevent heat from the light source from being transferred to the tip, the camera head housing may be configured to have an insulating section between the part where the light source is located and the tip.

[0049] The following describes an example configuration of such an imaging unit and an imaging system using it.

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

[0051] As shown in the figure, the imaging system 1000 comprises an imaging 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 examining various tissues and organs of living organisms, or as an industrial endoscope. In other words, the imaging system 1000 can be used in various fields such as industrial, medical, and scientific applications. The imaging system 1000 is configured to acquire imaging results of the imaging area near the tip of the imaging unit 1. The imaging system 1000 is configured to record the imaging results as an image or output them to an output device provided internally or externally.

[0052] As an example, the imaging system 1000 can be used to capture images to acquire information (hereinafter sometimes referred to as biological information) about the state of tissues or organs (hereinafter sometimes referred to as target sites) inside the body of a test organism. Here, the term "test organism" refers to animals such as mammals and other vertebrates, and may also be called a test animal. However, the term "test organism" is not limited to these, and may also include invertebrates such as insects and other bugs.

[0053] Biological information includes, for example, images showing the condition of a target area captured by an imaging unit, as well as other information and numerical values. It also includes information about the condition of the target area obtained based on this information (e.g., judgment results).

[0054] An image can be a still image or a moving image (video). A moving image can be considered to contain multiple still images. The format of the data recorded or output as an image is irrelevant.

[0055] Furthermore, the expression "outputting information" or "outputting information to a device" includes expressions such as displaying it on a screen, printing it on a medium using a printer, transmitting information to another device via a network, and passing it on to subsequent processing in information processing performed by a computer, etc.

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

[0057] The imaging unit 1 is connected to the image acquisition device 500 via a cable 590. The cable 590 includes, for example, signal lines for communication with the camera module 30, and power lines 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 that.

[0058] The image acquisition device 500 is, for example, a device equipped with a computer or the like, and is configured to drive the camera head 10 of the shooting unit 1 to capture images. In this embodiment, the image acquisition device 500 is configured to record the imaging results and to output the imaging results to an external terminal device 600 or the like for display on the display of the terminal device 600 or the like. The image acquisition device 500 may also have its own display and be configured to display the 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 as including 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 part of the image acquisition device 500. The power supply 570 also serves as the power source for the imaging unit 1. The power supply 570 is, for example, a battery, but is not limited to this. Furthermore, the imaging unit 1 may have its own battery or be configured to receive power from another power source.

[0061] The storage unit 510 is preferably made of a non-volatile recording medium, but can also be made of a volatile recording medium. The storage unit 510 stores the 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, transmitted via a communication line, or input via an input device. The information stored in the storage unit 510 may be temporary.

[0062] The storage unit 510 may also use a removable recording medium. In this case, the recording medium can be removed from the image acquisition device 500, and the information stored in the storage unit 110 can be read by an external device or the like.

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

[0064] The reception unit 530 may also be capable of receiving information entered via an input means. The input means can be anything, such as a numeric keypad, keyboard, mouse, or menu screen. In this case, the reception unit 530 can be implemented by a device driver for the input means such as a numeric keypad or keyboard, or by control software for the menu screen.

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

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

[0067] The image acquisition unit 540 and the camera head drive unit 550 are configured to operate, for example, by 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 it can communicate with it. The communication unit 560 may be implemented by, for example, wireless or wired communication means, but it may also be implemented by means for receiving broadcasts or broadcasting means. In this embodiment, the communication unit 560 is configured to communicate with, for example, an external terminal device 600, and to transmit images, which are the imaging results of the camera head 10, to the terminal device 600. That is, 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 to record the acquired information in the storage unit 510. For example, the image acquisition unit 540 may be configured to acquire biological information based on the information obtained by the imaging unit 1. For example, by automatically performing information processing in accordance with the purpose of observation, and by accumulating or transmitting the resulting biological information to an external device, the user can perform observations efficiently.

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

[0071] Figure 3 is a side cross-sectional view of the imaging unit 1. Figure 4 is a cross-sectional view taken along line AA in Figure 3. Figure 5 is a cross-sectional view taken along line CC in Figure 3. Figure 6 is a side cross-sectional view showing an enlarged view of the portion of the imaging unit 1 near the joint portion 70. Figure 7 is a view of the imaging unit 1 from the front end in the longitudinal direction.

[0072] In these figures, and in the following similar cross-sectional diagrams, hatching indicates the cross-section of a member; however, for illustrative purposes, hatching is not necessarily applied to the cross-section of all members.

[0073] The general structure of the imaging unit 1 is as follows:

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

[0075] In this embodiment, a male screw 13 is formed around the tip portion 12 of the camera head 10. The tip portion 12 is positioned on a mounting portion 71 provided inside the joint portion 70. That is, the mounting portion 71 is provided with a female screw that engages with the male screw 13, and the camera head 10 is connected to the joint portion 70 by screwing the male screw 13 into the mounting portion 71.

[0076] The joint portion 70 is configured to allow the optical element 80 to be fixed in place. The optical element 80 is fixed to the joint portion 70 and is positioned 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 component that extends in the longitudinal direction and adjusts the path of light between itself and the object being observed. The optical element 80 is arranged such that the longitudinal direction (axial direction) of the gradient-index lens 81 is the same direction as the longitudinal direction of the imaging unit 1. In this embodiment, the optical element 80 may be considered to include the gradient-index lens 81 and other associated components (for example, a fixing component 90).

[0078] The refractive index distribution lens 81 is fixed to the joint portion 70 via a fixing member 90, as will be described later. The refractive index distribution lens 81 is positioned such that the rear end portion 82 of the lens, which is the end face opposite to the side facing the object to be observed in the longitudinal direction, faces the front end portion 12 of the camera head 10. In this embodiment, most of the lens side surface 83 of the refractive index distribution 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 overall elongated shape. In this embodiment, the camera head 10 has an overall substantially cylindrical shape. However, the camera head 10 may be formed in a prism shape or may have partial irregularities. Figure 3 shows a cross-section of the camera head 10 in a plane passing through its central axis.

[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 can also be said that the housing 20 is formed in a tubular shape. The material of the housing 20 is not specified. It can be any material such as metal, ceramic, or resin. Each part of the camera head 10 is housed inside the housing 20. It can also be said that each part of the camera head 10 is located inside the housing 20 in the radial direction (the direction towards or away from the central axis of the camera head 10). The inner surface of the housing 20 has a cylindrical shape.

[0083] In this embodiment, the housing 20 is configured as a cylindrical shape having two parts with different diameters in the longitudinal direction. The housing 20 is configured such that the outer diameter of the part on the tip side 12 where the male screw 13 is formed is smaller than the outer diameter of the part further back. The outer diameter of the housing 20 may be substantially the same in the longitudinal direction. The housing 20 may also have, for example, a rectangular tubular part or a part 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 the part closer to the tip portion 12. The first cylindrical portion 21 is formed in a cylindrical shape. The male screw 13 is formed on the outer circumference of the first cylindrical portion 21. The second cylindrical portion 22 is the part closer to the rear end portion 19, opposite to the tip portion 12. The second cylindrical portion 22 is 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 section 23. The heat insulating section 23 is located between the first cylindrical section 21 and the second cylindrical section 22. The heat insulating section 23 is formed closer to the rear end section 19 than to the first cylindrical section 21. In the longitudinal direction, the housing 20 is constructed with the first cylindrical section 21, the rear end section 19, and the second cylindrical section 22 arranged in this order.

[0086] The heat insulating section 23 is made of a material with lower thermal conductivity than the second cylindrical section 22. In this embodiment, the heat insulating section 23 is made of a material with lower thermal conductivity than the first cylindrical section 21. Specifically, for example, the first cylindrical section 21 and the second cylindrical section 22 are made of metal, while the heat insulating section 23 is made of a material such as resin or ceramic. As a result, compared to the case where the entire housing 20 is made of a material with high thermal conductivity, such as metal, heat from the second cylindrical section 22 is less likely to be transferred to the first cylindrical section 21. This makes it possible to prevent the heat generated by the light source 40, etc., from affecting the part of the object to be photographed 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 molded separately. Each component is combined with the others by adhesive or other means to form a single 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 together 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 such that the portion of the second cylindrical portion 22 on the tip end 12 side covers the portion of the heat insulating portion 23 on the rear end 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 may be integrally molded and combined with the heat insulating portion 23. Alternatively, a different material may be used only for the portion corresponding to the heat insulating portion 23, and the housing 20 may be formed by machining or other processes on a base material that is integrally formed. Furthermore, the heat insulating portion 23 may be configured with insertion portions that open on both the front end 12 side and the rear end 19 side, and the cylindrical portions 21 and 22 may be inserted into each opening to form a single housing 20.

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

[0090] The camera module 30 is a module that packages an image sensor and an optical system such as a lens. For example, a known structure can be used as the camera module 30. The camera module 30 has a structure in which a light-receiving section 32, which is located at the front end of the camera head 10 and into which the light to be imaged is incident, an optical system including a lens, and an image sensor are arranged in that order. Wiring (not shown) connected to the image sensor is connected to the rear end of the camera module 30, i.e., the rear end of the image sensor. The wiring can be bundled together as a cable 590 and connected to an image acquisition device 500, etc.

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

[0092] The light source 40 is a light source that illuminates the imaging area when imaging is performed 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 also use other types of light sources, such as a laser diode. The light source 40 is connected to, for example, an electric wire (not shown) that is routed through a cable 590, and is powered by an image acquisition device 500 or the like to light up. The light source 40 has, for example, a rectangular parallelepiped shape, but is not limited to this, and may have other shapes such as cylindrical, coin-shaped, or flat.

[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 units 41 and the second light source units 42 are, for example, LED chips having a shape that is substantially rectangular overall, and are arranged to emit light from their front surfaces. The first light source units 41 and the second light source units 42 are configured to emit light of different wavelengths. In this embodiment, by providing the first light source units 41 and the second light source units 42, the structure of the optical fiber 45 that guides the light from each forward can be simplified. In addition, 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 to have two or more light sources 40. Preferably, at least two of the two or more light sources 40 are configured to emit light of different wavelengths, as in this 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, it is not limited to this, 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 sources 40 may pass through filters that transmit light of different wavelength bands, so that the camera head 10 can be illuminated with light of two or more wavelengths.

[0095] As shown in the figure, each light source 40 is positioned further from the tip 12 than the camera module 30 in the longitudinal direction. That is, each light source 40 is positioned behind the camera module 30. It can also be said that each light source 40 is behind the camera module 30 when viewed from the longitudinal front (tip 12 side) of the camera head 10. In this embodiment, most of the camera module 30 is located inside the first cylindrical portion 21, and the light sources 40 are located inside the second cylindrical portion 22. Because the light sources 40 are positioned away from the tip 12, and because the housing 20 is provided with an insulating portion 23, the heat generated by the light sources 40 is less likely to be transmitted to the tip 12, thus preventing it from affecting the subject. In addition, each light source 40 is positioned so that a part of it overlaps with the camera module 30 when viewed from the longitudinal front. This allows each part of the camera head 10 to be housed 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 these at least two light sources 40, the rear end of at least one light source 40 is located in front of the front end of the other at least one light source 40. By having at least two light sources 40 at different positions in the longitudinal direction in this way, each light source 40 can be housed in a housing 20 with a smaller diameter.

[0097] More specifically, in this embodiment, the two first light sources 41 of the camera head 10 are located in front of the two second light sources 42. In other words, in the longitudinal direction, the camera module 30, the two first light sources 41, and the two second light sources 42 are arranged in this order from the side closest to the tip 12. Each of the two first light sources 41 is sandwiched between the rear end of the camera module 30 and the front end of the second light source 42.

[0098] As shown in Figure 4, in this embodiment, the two first light sources 41 are arranged radially outward of the cable 590, with the cable 590 sandwiched between the two first light sources 41. Similarly, the two second light sources 42 are also arranged radially outward of the cable 590, with the cable 590 sandwiched between the two second light sources 42. In this embodiment, the first light sources 41 and the second light sources 42 are arranged to partially overlap when viewed from the longitudinal front. However, the positional relationship of the first light sources 41 and the second light sources 42 when viewed from the longitudinal front is not limited to this. It is preferable that two or more light sources 40 located at different positions in the longitudinal direction are arranged such that the positions from which they emit light are different when viewed from the longitudinal front. This arrangement allows for easy wiring of the optical fiber 45, as will be described later.

[0099] Furthermore, 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 front end 12 among the light sources 40, are in close proximity to each other. In this embodiment, of the light source 40 located closest to the front end 12, a portion of the front surface on the front end 12 side faces the rear end of the camera module 30 in the longitudinal direction. This structure, that is, the 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 Figure 4, makes it possible to further miniaturize the camera head 10.

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

[0101] In this embodiment, the optical fiber 45 has four optical fibers, each corresponding to a light source 40. Note that for one light source 40, two or more optical fibers or other elements may be provided to guide the light so that it 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 shown in Figure 5, that they are spaced apart from each other in the circumferential direction and aligned in the circumferential direction. Each optical fiber is spaced at approximately equal intervals in the circumferential direction. That is, the four optical fibers are spaced at approximately 90-degree intervals in the circumferential direction.

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

[0104] In this embodiment, the guide 25 is located inside the housing 20 near the tip portion 12. The guide 25 is positioned in the longitudinal direction, aligned with the camera module 30. As shown in the figure, the guide 25 is formed to fill the inside of the housing 20, excluding the camera module 30 and the optical fiber 45. Specifically, the guide 25 has a camera guide portion 26, which is a gap located approximately in the center and has a shape approximately identical to the cross-section of the camera module 30, and a fiber guide portion 27, which is a gap formed at the positions through which each of the four optical fibers 45 should pass. The side surface of the guide 25 is formed to have a shape approximately identical to the inner wall surface of the first cylindrical portion 21, and the guide 25 is configured to be housed inside the first cylindrical portion 21.

[0105] The presence of such guides 25 allows for the radial positioning of the camera module 30 and each optical fiber 45. Consequently, the camera head 10 can be easily manufactured, and its durability can be improved.

[0106] In this embodiment, the filter 50 is positioned 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 transparent section 51 for illumination and a second transparent section 52 for imaging, which are provided on a transparent substrate 53. Specifically, the first transparent section 51 is positioned on the substrate 53 and passes through the light emitted from the camera head 10. The second transparent section 52 is positioned on the substrate 53 and passes through the light incident on the camera head 10.

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

[0108] The first transmission section 51 is, for example, an excitation light filter. The first transmission section 51 allows only light in a specific wavelength range from the light guided by the optical fiber 45 to pass through and irradiates the imaging area with it. This light acts on fluorescent substances and fluorescent markers in the tissue within the imaging area, exciting them. The second transmission section 52 is, for example, a fluorescence filter. The second transmission section 52 is configured to allow only fluorescence in a specific wavelength range different from the excitation light to pass through, and precisely directs only the specific fluorescence signal generated after excitation into the light receiving section 32 of the camera module 30.

[0109] The second transparent section 52 is fixed to the camera module 30 so as to cover the front of the light-receiving section 32. The first transparent section 51 is positioned in front of the optical fiber 45 so as to close the gap between the second transparent section 52 and the inner surface of the housing 20. In other words, in this embodiment, the tip 12 of the camera head 10 is sealed by the filter 50. The rear end of the camera head 10 is sealed using, for example, a bonding material, but is not limited to this.

[0110] Furthermore, the filter 50 is not limited to having the characteristics described above. Filters with properties appropriate to the application may be used. Also, one or both of the first transmission section 51 and the second transmission section 52 may be omitted. In this case, a protective filter may be provided at the tip section 12, and no optical elements may be provided in addition to the camera module 30 and optical fiber 45. The filter 50 is a so-called optical filter, but it does not have to be one.

[0111] In this embodiment, the output portion 46 near the tip portion 12 of each optical fiber 45 is an inclined portion 47 formed to be inclined with respect to the longitudinal direction. The inclined portion 47 is the end face of the tip portion 12 of the optical fiber 45. It can also be said that the tip portion of each optical fiber 45 has an end face that is not substantially perpendicular to the direction in which the optical fiber 45 extends, but is cut at an angle. Because an inclined portion 47 is provided in each optical fiber 45 in this way, the output portion 46 of each optical fiber 45 is configured 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, each inclined portion 47 is formed to tilt away from the tip portion 12 in the longitudinal direction as it approaches 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 tilts 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 also be said that each inclined portion 47 is tilted so that the center of the camera head 10 is closer to the tip portion 12. With this configuration, a relatively large amount of light beam is emitted outward in the radial direction from the emission portion 46 of each optical fiber 45. That is, the emission portion 46 is configured to emit light guided from the light source 40 mainly outward in the radial direction.

[0113] Furthermore, the emission section 46 may not have an inclined section 47, and may have an optical element configured to diffuse light, or may be formed in a shape different from the inclined surface, thereby enabling the light guided from the light source 40 to be emitted in a direction different from the longitudinal direction. Alternatively, the emission section 46 may not have an emission section 46 at all, and light may be emitted mainly along the longitudinal direction from the end face of the optical fiber 45.

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

[0115] In this embodiment, the joint portion 70 has a mounting 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 Figure 7, in this embodiment, the joint portion 70 is formed in a substantially cubic shape, but is not limited to this. For example, it may be spherical or cylindrical. The joint portion 70 is made of metal, for example, but may be made of other materials such as engineering plastic.

[0116] The mounting portion 71 is a part formed so as to be recessed in the longitudinal direction from the side opposite to the side on which the optical element 80 is attached. The mounting portion 71 can also be described as a hole capable of accommodating the tip portion 12 of the camera head 10. The inner circumferential surface of the mounting portion 71 has a female thread that engages with the male thread 13 of the camera head 10. In other words, the male thread 13 is screwed into the mounting portion 71 so that the tip portion 12 of the camera head 10 can be attached.

[0117] The joint portion 70 is configured to allow a fixing screw 78 to be screwed in radially inward from the side. The tip of the fixing screw 78 can protrude from the inner circumferential surface of the mounting portion 71. By screwing the fixing screw 78 in so that it contacts the vicinity of the tip 12 of the camera head 10 that is screwed into the mounting portion 71, the camera head 10 can be fixed to the joint portion 70. The type of fixing screw 78 is not limited; for example, a headless set screw may be used, or a screw with a knob may be used. Alternatively, the fixing screw 78 may not be used at all. In this case, the mounting portion 71 and the male screw 13 may be formed such that a certain amount of torque is required when they are rotated relative to each other, or a thread locker may be interposed between the screws.

[0118] The fixing portion 72 is a recessed portion formed to open towards the front end of the imaging unit 1 in the longitudinal direction. The fixing portion 72 can be described as a hole formed so as to fit the fixing member 90, as will be described later. A hole 76 is formed on the inner circumferential surface of the fixing portion 72 for introducing adhesive 77 from the outer circumferential portion of the joint portion 70.

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

[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. As a result, the refractive index distribution lens 81, to which the fixing member 90 is attached and fixed to the fixing portion 72, and the camera head 10, which is attached to the mounting portion 71, are aligned coaxially. Therefore, the shooting unit 1 can be easily assembled to properly emit light and properly capture images.

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

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

[0123] As shown in Figure 8, the fixing member 90 has a through hole in the center into which a refractive index distribution type lens 81 can be inserted, and is formed in a cylindrical shape. A groove 92 is formed on the outer circumference 91 of the fixing member 90, recessing radially inward from the outer circumference 91. A projection 95 having a smaller outer diameter than the outer circumference 91 is formed in the axial direction of the fixing member 90. A contact surface 94 perpendicular to the axial direction is formed between the outer circumference 91 and the projection 95.

[0124] The outer periphery 91 or protrusion 95 and the through-hole into which the refractive index distribution lens 81 can be inserted are formed coaxially. This allows the refractive index distribution lens 81 and the camera head 10 to be positioned coaxially with high precision.

[0125] As shown in Figure 6, the optical element 80 is attached to the joint portion 70 such that the contact surface 94 of the fixing member 90 is in contact with a part of the joint portion 70, and the outer peripheral portion 91 faces a part of the joint portion 70. The fixing member 90 is positioned so as to be fitted inside the fixing portion 72. The protruding portion 95 of the fixing member 90 is fitted into a hole formed in the center of the fixing surface 74 and passing through the mounting portion 71. In this state, the fixing member 90 is fixed to the joint portion 70 by a method such as adhesive. For example, the fixing member 90 can be fixed to the joint portion 70 by filling the space between the fixing portion 72 and the outer peripheral portion 91 of the fixing member 90 with adhesive 77. The adhesive 77 can be filled through the hole 76 as described later, making it easy to fix the fixing member 90 to the joint portion 70. Since the adhesive 77 can be filled between the groove 92 of the fixing member 90 and the inner circumferential surface of the fixing part 72, the fixing member 90 can be securely fixed to the joint part 70.

[0126] Here, the inner diameter of the inner surface of the fixing portion 72 and the outer diameter of the outer periphery 91 of the fixing member 90 are set to be approximately the same dimension. The inner diameter of the hole in the center of the fixing surface 74 and the outer diameter of the protrusion 95 may also be set to be approximately the same dimension. This allows the refractive index distribution lens 81 and the camera head 10 to be arranged 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 portion 72. The fixing member 90 is fixed to the joint portion 70 with the contact surface 94 in contact with the fixing surface 74. Therefore, it is possible to assemble the assembly so that the position of the fixing member 90 relative to the joint portion 70 in the longitudinal direction is at a predetermined position.

[0128] Here, it is desirable that the dimensions of the axial projection 95, that is, the dimension from the contact surface 94 to the end of the projection 95 in the axial direction, be controlled with relatively high precision so that they meet predetermined dimensions. This allows for relatively easy alignment when fixing the refractive index distribution type lens 81 to the fixing member 90, by controlling the positional relationship between the end of the projection 95 and the rear end of the lens 82, thereby enabling high-precision setting of the position of the rear end of the lens 82 relative to the joint 70. Even when manufacturing multiple assemblies of the joint 70 and the optical element 80, the positional error of the rear end of the lens 82 can be easily reduced.

[0129] A stopper 98 is attached to the optical element 80. The stopper 98 is fixed to a predetermined position from the tip of the imaging unit 1 of the refractive index distribution lens 81, for example, by adhesive. In this embodiment, the stopper 98 is provided to position the imaging unit 1 relative to the organism under test. Note that the stopper 98 may be omitted.

[0130] In this embodiment, the stopper 98 has the same shape as the fixing member 90. That is, the same part can be used for both the fixing member 90 and the stopper 98. However, it is not limited to this, and a stopper 98 of any shape may be provided.

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

[0132] Figure 9 is a diagram illustrating the configuration of the filter 50 of the camera head 10.

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

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

[0135] Here, the camera head 10 can be made 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. A small filter 50 can be manufactured, for example, as follows.

[0136] Figure 10 illustrates an example of a method for manufacturing the filter 50.

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

[0138] The first member 51b and the second member 52b should be of a size that can be easily handled during manufacturing. The first member 51b and the second member 52b can be easily prepared, for example, by coating or vapor deposition on a transparent plate or film.

[0139] (Step S12) Next, the first member 51b and the second member 52b are partially placed on the transparent substrate 53. In this case, for example, the first member 51b and the second member 52b should be positioned in accordance with the positional relationship between the first transparent portion 51 and the second transparent portion 52 in the finished filter 50 (shown by a dashed line in the figure).

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

[0141] Subsequently, the camera head 10 can be manufactured by placing the cut-out filter 50 near the tip 12 of the camera head 10.

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

[0143] The method for manufacturing the filter 50 is not limited to this. For example, layers corresponding to the first transparent portion 51 and the second transparent portion 52 may be partially placed at predetermined positions on a substrate 53 such as glass by a method such as vapor deposition. In this case, to divide the regions in which each layer is formed during the manufacturing process of the filter 50, for example, photolithography technology may be used to sequentially perform photoresist coating, pattern exposure, and etching processes, but the method is not limited to this.

[0144] Next, a description of the manufacturing method for the imaging unit 1 according to this embodiment will be provided.

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

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

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

[0148] Next, the camera head 10 is fixed to the joint 70. That is, the tip 12 of the camera head 10 is screwed into the mounting portion 71 of the joint 70 (step S25). At this time, the position of the camera head 10 relative to the joint 70 may be adjusted so that a desired light emission or incidence state is obtained between it and the optical element 80. Then, at an appropriate position, the position of the camera head 10 relative to the joint 70 is fixed with a fixing screw 78 (step S26). This allows the camera head 10 to be attached to the joint 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 in-focus images and illuminating the subject appropriately. This positional relationship can be easily adjusted by rotating the camera head 10 around the joint 70, as the camera head 10 and the joint 70 are connected by screws. Furthermore, because the connection between the two is made by screws, changes in the positional relationship can be controlled with relatively high precision according to the screw pitch. For example, even when separating the camera head 10 and the joint 70 and then reassembling them, the state before separation can be easily reproduced by reassembling them with the same screw-in amount as before separation.

[0150] In this embodiment, to facilitate the management of the screw-in amount, markings may be provided on at least one of the camera head 10 housing 20 and the joint portion 70 for checking the screw-in amount and for recording information on the screw-in amount.

[0151] For example, as shown in Figure 12, a marking 17 may be provided on a portion of the outer circumference of the housing 20 in the circumferential direction. This makes it easier to accurately confirm how many rotations the camera head 10 has been positioned relative to the joint portion 70 when screwing the camera head 10 into the joint portion 70.

[0152] Figure 13 is a view of the joint portion 70 of the imaging unit 1, seen from the rear end in the longitudinal direction.

[0153] Furthermore, as shown in Figure 13, for example, markings 18 may be provided around the mounting portion 71 of the joint portion 70, arranged in the circumferential direction. 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 parts on the camera head 10, it becomes easier to accurately determine how many rotations the camera head 10 has been positioned relative to the joint portion 70.

[0154] However, the location and manner of the markings are not limited to these examples.

[0155] Next, we will describe an example of using the imaging system 1000 with the imaging unit 1.

[0156] Figure 14 illustrates an example of how to use the imaging system 1000 according to this embodiment.

[0157] Figure 14 shows an example of how the imaging system 1000 can be used to acquire images of the tissue state of a test organism 900. Here, the test organism 900 is, for example, a rodent, specifically a mouse. In this example, the imaging system 1000 is used to observe the activity of a specific area of ​​the mouse brain. For example, the tip of the imaging unit 1 is inserted near the area of ​​the brain to be observed, and light for observation is emitted to the area of ​​observation or the area is photographed to obtain the imaging result.

[0158] For this purpose, a small imaging unit 1 is used. For example, the imaging unit 1 is configured to be thin, with a diameter of about 1 to 2 millimeters, lightweight, and uses a thin refractive index distributed lens 81 for the part that is inserted into the body. By using such a small imaging unit 1, observation can be performed on the test organism 900 in a minimally invasive manner.

[0159] Furthermore, in this embodiment, the image acquisition device 500 is small and relatively lightweight, and can be held by the test organism 900.

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

[0161] In this embodiment, the imaging system 1000 is configured to be used 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, smartphone, tablet terminal, etc., or a server device. If the image acquisition device 500 is configured to be capable of wireless communication, it is desirable that the terminal device 600 be configured to send and receive information by wireless communication with the image acquisition device 500. The image acquisition device 500 may, for example, have a removable media configured to be detachable as an information storage unit, and may allow the terminal device 600, etc., to acquire information via the removable media.

[0162] In such usage examples, the imaging unit 1 can be attached to the subject organism 900 by, for example, the following attachment method.

[0163] Figure 15 is the first diagram illustrating an example of how to attach the imaging unit 1 to the test organism. Figure 16 is the second diagram illustrating an example of how to attach the imaging unit 1 to the test organism.

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

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

[0166] For example, consider a case where the area to be observed 990 is located at a predetermined depth from the epidermis 910 of the test 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 area to be observed 990 from the epidermis 910, and the stopper 98 is fixed in place beforehand. Then, by inserting the optical element 80 into the tissue of the test organism 900 so that the stopper 98 is close to the epidermis 910, the tip of the optical element 80 can be easily positioned in a suitable location for photographing the area to be observed 990.

[0167] Furthermore, with the optical element 80 attached to the test organism 900 in this manner, the imaging unit 1 can be prevented from falling off the test organism 900 by, for example, fixing the stopper 98 to the epidermis 910 or other parts with an adhesive (not shown).

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

[0169] (Step S54) Then, similar to step S26 described above, the position of the camera head 10 relative to the joint 70, that is, the distance D6 between the tip 12 of the camera head 10 and the rear end 82 of the lens, is fixed with the fixing screw 78. This allows the imaging unit 1 to be attached to the test organism 900 so that it can be observed.

[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 shooting unit 1 can be easily handled.

[0171] Since the camera head 10 and the joint 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 makes it possible to disassemble the shooting unit 1 for cleaning and maintenance, ensuring long-term durability. For example, even if dirt adheres to 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 it.

[0172] Furthermore, the imaging unit 1 is configured so that the optical element 80, which is close to the object of observation, and the camera head 10 can be separated. Therefore, attachment to the test organism 900, etc., can be carried out in an easy and reliable procedure. For example, even when the object of observation is a small animal or when observation is required in a narrow body cavity, the optical element 80 can be placed first, and then the camera head 10 can be attached, allowing for efficient and safe installation. Also, depending on the observation method, the optical element 80 and joint part 70 can be discarded, while the camera head 10 can be reused, making it possible to perform multiple observations at low cost. Moreover, this structure allows for flexible operation by changing only the optical element 80 to adapt to different observation methods and conditions. For example, by changing the optical element 80 to one that corresponds to a different wavelength, different types of fluorescence observation can be performed with the same camera head 10. In addition, because the optical element 80 is replaceable, it is easy to improve observation accuracy and introduce new observation techniques by using an element specialized for a specific object of observation. Furthermore, by discarding the optical element 80 after observation, hygiene risks can be reduced, and safety can be improved, especially in medical applications.

[0173] The inclined portion 47 is provided at the output end 46 of each optical fiber 45, which effectively diffuses the light guided from the light source 40 radially, enabling uniform illumination of the entire observation target. As a result, uniform illumination is provided over a wide observation area without light concentration in a particular direction, reducing image unevenness and improving observation accuracy. In particular, because the inclined portion 47 is inclined outward from the center of the tip 12 with respect to the longitudinal direction, the light beam is efficiently dispersed toward the outer periphery of the camera head 10, allowing light to be evenly illuminating the observation target. Since this can be achieved with a simple structure, the imaging unit 1 can be miniaturized, and manufacturing costs can be kept low.

[0174] (Embodiment 2)

[0175] The outline of Embodiment 2 of the present invention will now be described in terms of the parts that differ from Embodiment 1 described above. In Embodiment 2, a shooting unit 201 having the same configuration as Embodiment 1 except for the following parts is used. In this embodiment, a guide member is used which is positioned near the rear end of the refractive index distribution lens 81 and configured to direct a portion of the light emitted from the front end 12 of the camera head 210 onto the side surface of the refractive index distribution lens 81. In addition, a plurality of light sources 40 are arranged in series in the longitudinal direction. Furthermore, a camera head 210 having a housing 220 with a substantially straight tube shape is used. Filters 250 are provided separately in the paths corresponding to each light source 40 and camera module 30.

[0176] Figure 17 is a side cross-sectional view of the imaging unit 201 according to Embodiment 2 of the present invention.

[0177] As shown in Figure 17, the imaging 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 mounting portion 71 of the joint portion 270.

[0179] In the camera head 210, four light sources 40 are housed in a line along the longitudinal direction. That is, two first light source units 41 and two second light source units 42 are positioned one at a time at different locations behind the camera module 30. Optical fibers 45 are provided from each light source 40 to the vicinity of the tip 12. By adopting this layout of light sources 40, a thinner camera head 210 can be constructed.

[0180] In this embodiment 2, the filter 50 is not provided, and instead, four first filters 251 are placed between each light source 40 and the optical fiber 45, and a second filter 252 is provided so that light incident on the camera module 30 is transmitted. With this group of filters 250 provided, light irradiation and photography can be performed in the same manner as in embodiment 1 described above.

[0181] Each filter 250 can be cut from a larger component, but the manufacturing method is not limited to this. Compared to constructing a small filter 50 that has different types of permeable sections integrated into one unit, the filters 250 can be prepared more easily.

[0182] The optical element 280 according to Embodiment 2 does not have the fixing member 90 for the optical element 80 described above. The optical element 280 has a refractive index distribution type lens 81 and a guide member 285 provided near the rear end portion 82 of the lens.

[0183] A through-hole is provided in the center of the guide member 285, formed so that the refractive index distribution lens 81 passes through it. The guide member 285 is attached to the refractive index distribution lens 81 such that the rear end portion 82 of the lens is exposed from a part of the rear end surface of the guide member 285.

[0184] The outer surface of the guide member 285 is, for example, coaxial with the central axis of the refractive index distribution lens 81 and is part of a conical surface having a generatrix that intersects the central axis on the front side of the rear end 82 of the lens. That is, the guide member 285 has a side cross-sectional shape in which the radial dimension increases as it approaches the rear end 82 of the lens in the longitudinal direction. 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 rear end of the lens 82 are exposed to the mounting portion 71. In other words, the light emitted from the tip portion 12 of the camera head 210 is configured to also enter the guide member 285 from its rear end. The light that enters the guide member 285 either passes through the inside of the guide member 285 and enters the lens side surface 83, or is reflected inward on the outer circumferential surface of the guide member 285 and enters the lens side surface 83. In other words, the guide member 285 has a reflective portion 287 which is the outer circumferential surface of the guide member 285. The reflective portion 287 reflects light that enters from behind the guide member 285 radially inward at a point in the axial direction forward of the rear end of the lens 82 of the refractive index distribution type lens 81.

[0186] The reflective portion 287 may be a portion configured to totally reflect most of the light incident from the rear, or it may be a portion that is coated to form a mirror surface or the like in order to reflect more light.

[0187] The presence of such a reflective section 287 allows light irradiated not only from the rear end 82 of the lens, but also from the radially outer portion thereof, to be irradiated from the tip of the optical element 280 through the refractive index distribution lens 81. This widens the incident range of light, making it possible to appropriately utilize the light from the light source 40 while keeping the imaging unit 201 compact. In particular, because the reflective section 287 efficiently collects light on the side surface 83 of the lens, the uniformity of the irradiated light on the object of observation can be improved, and a detailed and clear image can be obtained.

[0188] (others)

[0189] In the above embodiment, each component of the image acquisition device may be configured with dedicated hardware, or, if a component can be implemented by software, it may be implemented by executing a program. For example, each component can be implemented 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 the storage unit or recording medium. Furthermore, the program may be executed by being downloaded from a server or the like, or by being executed by reading a program recorded on a predetermined recording medium (e.g., an optical disk, magnetic disk, or semiconductor memory). This program may also be used as a program that constitutes a program product.

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

[0191] Furthermore, in the above embodiment, information related to the processing performed by each component, such as information received, acquired, selected, generated, transmitted, or received by each component, as well as information such as thresholds, formulas, and addresses used by each component in processing, may be temporarily or for a long period of time stored in a recording medium (not shown), even if not explicitly stated in the above description. The storage of information in the recording medium (not shown) may be performed by each component or a storage unit (not shown). 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 embodiments described above, and various modifications are possible, which are also included within the scope of the present invention.

[0193] Embodiments may be constructed by appropriately combining the components of the embodiments and modifications described above. For example, each component of the embodiments and modifications described above may be appropriately replaced or combined with components of other modifications, etc. Furthermore, some components or functions of the embodiments and modifications described above may be omitted.

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

[0195] Furthermore, one first light source and one second light source may be arranged at approximately the same position in the longitudinal direction, with another first light source and another second light source arranged behind them. Alternatively, the first light source may be at the rear and the second light source at the front. In addition, any one of these first and second light sources may be positioned in front of or behind the others.

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

[0197] Furthermore, the camera head described in the above-described embodiment may be used by attaching it to the test organism on its own, that is, without attaching an optical element to its tip. In other words, the camera head can be used either on its own or as a shooting unit with a joint and optical element attached. Therefore, the camera head is highly versatile and can be used for various purposes. In this case, it is preferable that the tip of the camera head is covered with a filter or other optical component to ensure liquid-tightness. [Industrial applicability]

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

[0199] 1,201 shooting units 10,210 Camera Heads 12 Tip 13 Male screw 20,220 units 21 First cylinder part 22 Second cylinder part 23 Insulation section 25 Guide 30 Camera Modules 40 light source 41 First light source section 42 Second light source section 45 Optical Fiber 46. ​​Ejection section 47 Slope 50 filters 51 First transmission part 52 Second transmission section 53 circuit boards 70 Joint section 71 Mounting part 76 holes 77 Adhesives 78 Fixing screws 80,280 optical elements 81. Refractive index distributed lens 82 Rear end of lens 83 Lens side 90 Fixing components 91 Outer periphery 92 Groove 94 Contact surface 98 Stopper 251 First Filter 252 Second Filter 285 Guide Member 287 Reflector

Claims

1. Optical elements and A joint portion that can be fixed to the optical element, The system comprises a camera head located on the side closest to the optical element, into which light from the optical element is incident, and having a tip portion that emits light to the optical element, A male thread is formed around the tip portion. The joint portion has a mounting portion into which the male screw is screwed, The aforementioned tip is an imaging unit located inside the aforementioned joint.

2. The optical element is a refractive index distribution lens that extends in the longitudinal direction and adjusts the path of light between itself and the object being observed. The aforementioned camera head is A camera module provided near the tip portion, A light source positioned behind the camera module, It has an optical fiber extending from the light source to the vicinity of the tip, The imaging unit according to claim 1, wherein the tip of the optical fiber has an emission portion configured to emit at least a portion of the light guided from the light source in a direction different from the longitudinal direction of the refractive index distribution lens.

3. The refractive index distribution lens, the joint portion, and the camera head are arranged in the longitudinal direction of the refractive index distribution lens. The emission portion is an inclined portion which is the end face of the tip of the optical fiber formed to be inclined with respect to the longitudinal direction of the refractive index distribution type lens, The imaging unit according to claim 2, wherein the inclined portion is formed to move away from the tip in the longitudinal direction of the refractive index distribution lens as it approaches the center of the tip in a direction perpendicular to the longitudinal direction of the refractive index distribution lens.

4. The camera head has a housing having a portion on which the male screw is formed, Each part of the camera head is housed inside the housing. The aforementioned enclosure is The first cylindrical portion is a cylindrical part located near the tip, A cylindrical portion located near the rear end opposite to the aforementioned tip, comprising at least a second cylindrical portion on which the light source is positioned on the inside, The imaging unit according to claim 2, further comprising an insulating section disposed between the first cylindrical section and the second cylindrical section, and formed of a material with lower thermal conductivity than the second cylindrical section.

5. The imaging unit according to claim 2, wherein the camera head is positioned near the tip and has a guide for positioning the camera module and the optical fiber (in the radial direction).

6. The aforementioned camera head is A first filter is placed between the light source and the optical fiber, The imaging unit according to claim 2, further comprising a second filter arranged to transmit light incident on the camera module.

7. The camera head is positioned near the tip and has a filter through which light incident on the camera head and light emitted from the camera head are transmitted. The aforementioned filter is A transparent substrate and A first transparent portion is arranged on the substrate and through which emitted light is transmitted, The imaging unit according to claim 1, further comprising a second transmissive portion disposed on the substrate through which incident light is transmitted.

8. The optical element extends in the longitudinal direction and has a rear end and side surfaces. The imaging unit according to claim 1, further comprising a guide member positioned 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 onto the side surface of the optical element.

9. The imaging unit according to claim 8, wherein the guide member has a reflective portion in a portion forward of the rear end of the optical element that reflects light incident from the rear toward the inner side of the optical element.

10. The optical element is a member that extends in the longitudinal direction, The optical element is equipped with a fixing member attached to the end of the optical element on the side closer to the camera head in the longitudinal direction, A groove is formed on the outer circumference of the aforementioned fixing member. The optical element is attached to the joint such that the contact surface of the fixing member in the longitudinal direction is in contact with a part of the joint, and the outer circumference faces a part of the joint. The imaging unit according to claim 1, wherein an adhesive is disposed between the groove and the joint.

11. A camera head usable in the shooting unit described in claim 1, The casing and The housing has a camera module provided near the tip of the housing, A camera head having a male thread formed around the tip of the housing, which can be screwed into the mounting portion of the joint.

12. A method for manufacturing a camera head comprising a male screw that can be screwed into the joint portion of the shooting unit, and a filter positioned near the tip portion to which the joint portion is attached, wherein light that has passed through a first transparent portion in a part of the filter is emitted toward the joint portion, and light that has entered from the joint portion passes through a second transparent portion in a part of the filter, The steps include: preparing a first member having the first permeable portion, The steps include: preparing a second member having the second permeable portion; The steps include partially arranging the first member and the second member on a transparent substrate, The steps include cutting the substrate on which the first member and the second member are arranged into the shape of the filter, A method for manufacturing a camera head, comprising the step of arranging the cut-out filter near the tip portion.

13. A method for attaching an imaging unit according to any one of claims 1 to 10 to a test organism, The steps include fixing the joint portion to the optical element, The steps include attaching the optical element to the organism under test, A method for attaching a shooting unit, comprising the step of screwing the tip of the camera head into the mounting portion of the joint portion to attach the camera head to the joint portion.

14. The step includes fixing a stopper at a predetermined distance backward from the tip of the optical element, The method for attaching the imaging unit according to claim 13, wherein the step of attaching the optical element to the organism under test is to attach the optical element to the organism under test such that the stopper is positioned in a predetermined position relative to the organism under test.

15. A fixing member is attached to the end of the optical element. A groove is formed on the outer circumference of the aforementioned fixing member. The method for mounting a photographic unit according to claim 13, wherein the step of fixing the joint portion includes, with the outer circumference of the fixing member inserted inside the joint portion, inserting adhesive between the joint portion and the groove portion through a hole provided in the joint portion.

16. The method for attaching a shooting unit according to claim 13, 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 that a desired light emission or incidence state can be obtained with respect to the optical element, and fixing the position of the camera head relative to the joint portion with fixing means.

Images