Endoscope

Abstract

An endoscope in which a light emitting module is assembled to a front end portion of an insertion tube, the light emitting module including a mounting substrate on which a plurality of light emitting elements are mounted, the mounting substrate being ring-shaped, having a hole in a central portion thereof through which an image pickup element using the light emitting elements as light sources is inserted, and having a first surface on which the light emitting elements are surface-mounted and a side surface located at a periphery of the first surface, the side surface having a conductive portion that is in conduction with the light emitting elements, and a power supply line that is connected to the conductive portion and supplies electric power to the light emitting elements.

Description

[0001] This application claims priority based on Japanese Application No. 2021-017376, filed on February 5, 2021, and incorporates all disclosures set forth in that Japanese application. Technical Field

[0002] This technology relates to an endoscope. Background Technology

[0003] An endoscope is a medical device that allows observation and treatment of desired areas by inserting it into a subject's body cavity. It includes: a camera unit, the front end of which is assembled into an insertion tube inserted into the body cavity; and an illumination device that illuminates the field of view of the camera unit. Patent Document 1 discloses an endoscope equipped with an illumination device that achieves illumination over a wide angle of 180° and enables wide-angle observation.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2015-16021 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] However, the endoscope device described in Patent Document 1 has the following problem: when providing a conductive part connected to a power line for supplying power to the lighting device, aspects related to the proper configuration of the conductive part are not considered.

[0009] On one hand, the object of the present invention is to provide an endoscope that can be appropriately configured with a conductive portion connected to a power line for supplying power to a light-emitting element.

[0010] Technical solutions for solving the problem

[0011] According to one embodiment of the present disclosure, an endoscope is provided in which a light-emitting module is assembled at the front end of an insertion tube. The light-emitting module includes a mounting substrate on which a plurality of light-emitting elements are mounted. The mounting substrate is annular and has a hole in its central part for inserting an imaging element that uses the light-emitting elements as a light source. It has a first surface on which the light-emitting elements are mounted and a side surface located at the periphery of the first surface. A conductive part that is in communication with the light-emitting elements is provided on the side surface, and a power line for supplying power to the light-emitting elements is connected to the conductive part.

[0012] Invention Effects

[0013] According to this disclosure, an endoscope may be provided which may be suitably configured with a conductive portion connected to a power line for supplying power to a light-emitting element. Attached Figure Description

[0014] Figure 1 This is an external view of the endoscope involved in Embodiment 1.

[0015] Figure 2 This is an enlarged view of the front end of the insertion tube.

[0016] Figure 3 This is an explanatory diagram illustrating an example of the connection status between the mounting base and the power cord.

[0017] Figure 4 This is a schematic plan view illustrating an example of mounting a substrate.

[0018] Figure 5 This is a schematic side sectional view illustrating an example of mounting a substrate.

[0019] Figure 6 This is a schematic side sectional view illustrating an example of the mounting substrate involved in Embodiment 2 (the recess on the heat sink). Detailed Implementation

[0020] (Implementation Method 1)

[0021] The invention will be described in detail below with reference to the accompanying drawings illustrating its embodiments. Figure 1 This is an external view of the endoscope 1 according to Embodiment 1. The endoscope 1 includes an insertion tube 2, an operating section 3, a universal tube 4, and a connector section 5. The insertion tube 2 is the portion inserted into the body cavity, and it includes a long flexible section 20 and a front end portion 22, the front end portion 22 being connected to one end of the flexible section 20 via a bend 21. The other end of the flexible section 20 is connected to the operating section 3 via a cylindrical connecting portion 23. One end of the universal tube 4 is connected to the operating section 3 and extends in a direction different from that of the insertion tube 2; the connector section 5 is connected to the other end of the universal tube 4.

[0022] The operating section 3 is designed for easy gripping by the endoscope 1 user (operator), such as a doctor, to perform various operations. It includes a bendable operating knob 30 and multiple operating buttons 31. The bendable operating knob 30 is connected to the bendable section 21 via a metal wire (not shown) passing through the connecting section 23 and the flexible section 20. The bendable section 21 bends in two mutually orthogonal directions within its axial section according to the operation of the bendable operating knob 30, changing the direction of the front end 22 inserted into the body cavity.

[0023] The endoscope 1 is connected to the processor device 10 via the connector 5 and is used as an endoscope device. The processor device 10 includes a control unit, a storage unit, signal processing circuits, etc., and performs comprehensive control of the endoscope device through the control program stored in the storage unit.

[0024] Figure 2 This is an enlarged view of the front end of the insertion tube. The front end 22 has a tubular housing 24 fixed to the bend 21 on one side. The other side of the housing 24 is covered by a central objective lens 25 and an annular light-distributing lens 26 surrounding the objective lens 25. Inside the housing 24, an imaging element 6 is assembled on the inner side facing the objective lens 25. The imaging element 6 takes pictures of the object being observed (the subject) as an internal part such as a body cavity through the objective lens 25. The objective lens 25 is embedded in the inner frame of the hole provided on the front end 22 of the insertion tube 2, and functions as an observation window. A light-emitting module 7 is assembled on the inner side facing the light-distributing lens 26.

[0025] The imaging element 6 comprises a semiconductor element such as a CMOS (Complementary Metal Oxide Semiconductor) and an optical system that images onto the imaging surface, and captures images of the body cavity through the objective lens 25. The objective lens 25 is, for example, a wide-angle lens, and the imaging element 6 is configured to capture images from a specified angle of 180° or more, depending on the settings of the optical system, including the objective lens 25. The imaging element 6 outputs the captured image data (image signal) of the observed object (subject) via a signal line connected to the imaging element 6. The captured image data (image signal) output by the imaging element 6 undergoes preprocessing such as AD conversion or white balance correction, and is then output to the processor device 10.

[0026] The light-emitting module 7 includes: an annular mounting substrate 72 surrounding the image sensor 6; and a plurality of light-emitting elements 71 mounted on a first surface (mounting surface) of the mounting substrate 72 opposite to the light-distributing lens 26. These plurality of light-emitting elements are, for example, composed of white LEDs, narrow-band LEDs, or a combination of both. The plurality of light-emitting elements are arranged at equal intervals along the circumference of the annular mounting substrate 72, for example, in groups of one or two. A circular hole is formed in the center of the annular mounting substrate 72, and the image sensor 6 is located at the center of this circular hole. Thus, the outer peripheral surface of the image sensor 6 is opposite to the inner peripheral surface (inner peripheral side surface) of the hole formed on the mounting substrate 72.

[0027] The light-distributing lens 26 is a cylindrical lens with the following shape: it extends outward from the periphery of the objective lens 25 and is continuous with the peripheral wall of the housing 24 via a curved portion. Light from the light-emitting element 71 is emitted through the light-distributing lens 26 to illuminate the field of view of the imaging element 6. The imaging element 6 performs imaging under the illumination emitted by the light-emitting element 71.

[0028] Figure 3 This is an explanatory diagram illustrating an example of the connection state between the mounting base plate 72 and the power line 8. Figure 4 This is a schematic plan view illustrating an example of mounting substrate 72. Figure 5 This is a schematic side sectional view illustrating an example of the mounting substrate 72. The mounting substrate 72 is a multilayer substrate formed by stacking multiple substrates 720 (four substrates 720 in this embodiment). The mounting substrate 72 includes a first surface 721, which serves as a mounting surface for mounting the light-emitting element 71, and a second surface 722 located on the opposite side of the first surface 721. A heat sink 9 is provided in close contact on the second surface 722. Thus, the heat sink 9 is thermally connected to the mounting substrate 72.

[0029] In each of the substrates 720 constituting the mounting substrate 72 which is a multilayer substrate, the first surface 721, which is the mounting surface on which the light-emitting element 71 is mounted, corresponds to the surface of the substrate 720 located at the foremost side (objective lens 25 side), and the second surface 722, which is in close contact with the heat sink 9, corresponds to the back side of the substrate 720 located at the rearmost side (bend 21 side).

[0030] The side surface located at the periphery of the first surface 721 includes an inner peripheral side surface 723, which serves as the inner peripheral surface of a hole 73 formed on the annular mounting substrate 72, and an outer peripheral side surface 726 of the mounting substrate 72. A plurality of cutouts 724 cut along the thickness direction of the mounting substrate 72 are formed on the inner peripheral side surface 723. That is, cutouts 724 are formed on each side surface of the substrate 720 constituting the mounting substrate 72 as a multilayer substrate, and these cutouts 724 of the substrate 720 are provided continuously in the thickness direction of the substrate 720, thereby forming a groove-shaped cutout 724 along the thickness direction of the multilayer substrate on the inner peripheral side surface 723 of the multilayer substrate.

[0031] The notch 724 can be formed on all substrates 720 constituting the mounting substrate 72 (multilayer substrate), or it can be formed only on substrates 720 including at least a portion of the substrate 720 having a first surface 721, which is the mounting surface on which the light-emitting element 71 is mounted. In this embodiment, the notch 724 is formed on substrates 720 other than the substrate 720 in close contact with the heat sink 9 among the plurality of substrates 720 constituting the multilayer substrate. That is, the notch 724 is not provided on the substrate 720 in close contact with the heat sink 9, i.e., the substrate 720 with the second surface 722. In this way, among the plurality of substrates 720 constituting the multilayer substrate, by not providing the notch 724 and the conductive portion 725 on the substrate 720 in close contact with the heat sink 9, the heat sink 9 can be insulated from the conductive portion 725 provided on the notch 724 of the other substrates 720 by using the substrate 720 in close contact with the heat sink 9.

[0032] A conductive portion 725 is provided in a groove formed along the thickness direction in the cutout 724 formed on the inner peripheral side surface 723. The conductive portion 725 is made of a conductive material with good conductivity, such as copper, copper alloy, or conductive paste, for example, a solder pad for cable connection. The conductive portion 725 is provided in a manner that fills the cutout 724 (groove) formed on the inner peripheral side surface 723.

[0033] The end of the conductive portion 725 on the first surface 721 side can also be positioned above the first surface 721 and be L-shaped. As illustrated in this embodiment, in the L-shaped conductive portion 725, the portion of the conductive portion 725 located at the cutout portion 724 corresponds to the longitudinal side of the L-shape, and the portion of the conductive portion 725 located above the first surface 721 corresponds to the transverse side of the L-shape. The core wire 81 of the power supply line 8 is joined to the portion of the conductive portion 725 corresponding to the longitudinal side of the L-shape.

[0034] The conductive portion 725 is electrically connected to the terminals or pads 711 of the light-emitting element 71 via wiring patterns, pads, or vias provided on the surfaces of the first surface 721 and each of the stacked substrates 720. As described above, the light-emitting element 71 is composed of an LED or the like, and the conductive portion 725 includes a conductive portion 725 (positive electrode side conductive portion) connected to the anode (positive electrode side) of the LED and a conductive portion 725 (negative electrode side conductive portion) connected to the cathode (negative electrode side).

[0035] The number of conductive portions 725 is determined based on the control method for each of the plurality of light-emitting elements 71. For example, when eight light-emitting elements 71 (LEDs) are mounted, eight conductive portions 725 (positive electrode conductive portions) are provided on the anode side while controlling the brightness of each light-emitting element 71 (LED). The cathode side can be provided with one conductive portion 725 (negative electrode conductive portion) integrated into one circuit, or two conductive portions 725 (negative electrode conductive portions) that provide redundancy for wire breaks as two circuits. In this way, the number of conductive portions 725 (negative electrode conductive portions) on the cathode side can be less than the number of conductive portions 725 (positive electrode conductive portions) on the anode side.

[0036] The cutout 724 and conductive portion 725 provided on the inner peripheral side surface 723 of the mounting substrate 72 can be formed by half-cutting the VIA (through hole) when forming (cutting through) the hole 73 for surrounding the mounting substrate 72, or the pattern can be formed after the mounting substrate 72 is formed.

[0037] A core wire 81 of a power line 8 extending from the processor device 10 is joined to the conductive part 725. Power from the processor device 10 is supplied to the light-emitting module 7 via the power line 8 and the conductive part 725 to illuminate the light-emitting element 71.

[0038] The power cord 8, extending from the processor device 10 side, is connected parallel to the conductive portion 725, i.e., parallel to the slotted cutout 724 provided along the thickness direction of the multilayer substrate, with reference to the extension direction of the insertion tube 2. Thus, the axial direction of the core wire 81 of the power cord 8, which is bonded to the conductive portion 725, is parallel to the extension direction of the insertion tube 2 and aligns with the thickness direction of the mounting substrate 72. This core wire 81 is also located inside the hole 73 of the mounting substrate 72. In this way, the power cord 8, extending from the processor device 10 side, is connected parallel to the conductive portion 725 in the extension direction of the insertion tube 2. Therefore, bending of the power cord 8 can be suppressed near the point of connection to the conductive portion 725. This suppresses stress generated in the direction in which the power cord 8 is peeled from the conductive portion 725 and ensures or improves the connection strength between the power cord 8 and the conductive portion 725.

[0039] The heat sink 9 is made of a metal with high thermal conductivity and is composed of the same annular plate component as the mounting substrate 72. Like the mounting substrate 72, the annular heat sink 9 has a hole in its center, and the hole in the heat sink 9 and the hole 73 in the mounting substrate 72 form concentric circles. Multiple power lines 8 and signal lines connected to the imaging element 6 are located inside the hole in the heat sink 9.

[0040] The heat sink 9 is in close contact with the second surface 722 of the mounting substrate 72, and the mounting substrate 72 and the heat sink 9 are thermally connected. Thus, the heat generated by the light-emitting element 71 is dissipated to the surrounding space via the heat sink 9, suppressing the temperature rise of the light-emitting element 71 and cooling it down. Of course, the second surface 722 of the mounting substrate 72 is electrically insulated from the heat sink 9. It is not limited to the mounting substrate 72 (second surface 722) and the heat sink 9 (contact surface 91) being directly in contact; insulating thermal paste can also be applied between the mounting substrate 72 (second surface 722) and the heat sink 9 (contact surface 91).

[0041] The outer peripheral surface of the imaging element 6 faces the inner peripheral side surface 723 of the mounting substrate 72, where the conductive portion 725 is provided. An insulating resin component or the like can be disposed in the gap formed between the outer peripheral surface of the imaging element 6 and the inner peripheral side surface 723 of the mounting substrate 72. By encapsulating and disposing of the insulating resin component or the like in this gap, insulation between the conductive portion 725 and the core wire 81 connected to the conductive portion 725 and the imaging element 6 can be ensured.

[0042] In this embodiment, the cutout portion 724 and the conductive portion 725 are provided on the inner peripheral side surface 723 of the mounting substrate 72, but this is not a limitation; they may also be provided on the outer peripheral side surface 726 of the mounting substrate 72. In this embodiment, the mounting substrate 72 is a multilayer substrate, but this is not a limitation; the mounting substrate 72 may also be a single-layer substrate composed of a single substrate 720.

[0043] According to this embodiment, a conductive portion 725 connected to a power line 8 for supplying power to the light-emitting element 71 is provided on an inner peripheral side surface 723, which is located at the periphery of the first surface 721 on which the light-emitting element 71 is mounted. Therefore, it is unnecessary to provide the conductive portion 725 (the portion of the conductive portion 725 that engages with the core wire 81) on the first surface 721; instead, the conductive portion 725 can be appropriately disposed on the mounting substrate 72, which is built into the front end of the insertion tube 2. This reduces the area of ​​the first surface 721 and the size of the front end of the insertion tube 2 assembling the light-emitting module 7. By reducing the area of ​​the first surface 721, the diameter of the hole 73 provided on the mounting substrate 72 can be increased. Therefore, without increasing the outer diameter of the mounting substrate 72 and the size of the front end of the insertion tube 2, the size of the imaging element 6 inserted and disposed in the hole 73 can be increased. This design allows for an expansion of the mounting space on the first surface 721, increasing the degree of freedom in the arrangement (installation freedom) of the light-emitting elements 71 on the first surface 721, increasing the number of light-emitting elements 71 that can be installed, and allowing for the arrangement of multiple such light-emitting elements 71. Since the conductive portion 725 is provided on the inner peripheral side surface 723 of the hole 73 through which the imaging element 6 is inserted, the conductive portion 725 can be provided inside the hole 73. This allows for a reduction in the size of the front end of the insertion tube 2.

[0044] According to this embodiment, the conductive portion 725 is provided on the cutout portion 724 formed on the side surface, thereby reducing the height of the protrusion formed between the conductive portion 725 and the side surface where the cutout portion 724 is not formed. When the side surface where the cutout portion 724 is formed is the inner peripheral side surface 723 constituting the inner peripheral surface of the hole 73, by providing the conductive portion 725 on the cutout portion 724, it is possible to suppress the conductive portion 725 from protruding on the inner peripheral surface of the hole 73 and to increase the diameter of the hole 73.

[0045] According to this embodiment, by constructing the mounting substrate 72 from a multilayer substrate formed by stacking multiple substrates 720, the wiring freedom of the wiring pattern used to connect the conductive portion 725 and the light-emitting element 71 can be improved. In the mounting substrate 72 constructed from the multilayer substrate, the heat sink 9, such as a heat sink, is in close contact with the second surface 722 located on the opposite side of the first surface 721, which serves as the mounting surface of the light-emitting element 71. Among the multiple substrates 720 constituting this multilayer substrate, cutouts 724 are provided on substrates 720 other than those in close contact with the heat sink 9, but no cutouts 724 are provided on the substrates 720 in close contact with the heat sink 9, i.e., the substrates 720 having the second surface 722. Therefore, conductive portions 725 are not provided on the substrates 720 in close contact with the heat sink 9 (including the substrates 720 with the second surface 722). In this way, among the multiple substrates 720 constituting the multilayer substrate, by not providing the cutout portion 724 and conductive portion 725 on the substrate 720 that is in close contact with the heat sink 9, the heat sink 9 can be insulated from the conductive portion 725 provided on the cutout portion 724 of the other substrates 720 by using the substrate 720 that is in close contact with the heat sink 9.

[0046] According to this embodiment, the power cord 8 extending from the processor device 10 side is connected parallel to the conductive portion 725 in the extending direction of the insertion tube 2. Therefore, bending of the power cord 8 can be suppressed near the location where it connects to the conductive portion 725. This suppresses stress generated when the power cord 8 is peeled from the conductive portion 725 and improves the connection strength (reliability of the solder joint) between the power cord 8 and the conductive portion 725. By providing the core wire 81 of the power cord 8 on the inner peripheral side surface 723, bending of the power cord 8 can be suppressed. Therefore, the bent portion (R portion) formed by the bending (folding) will not interfere with the imaging element 6 at the center of the insertion hole 73. Thus, the inter-surface distance (gap) between the inner peripheral side surface 723 of the mounting substrate 72 and the outer peripheral surface of the imaging element 6 only needs to ensure the outer diameter of the power cord 8, reducing the inner diameter of the hole 73 in the mounting substrate 72 (inner diameter of the mounting substrate 72).

[0047] (Implementation Method 2)

[0048] Figure 6 This is a schematic side cross-sectional view illustrating an example of the mounting substrate 72 according to Embodiment 2 (the recess 92 on the heat sink 9). In this embodiment, cutouts 724 are formed on the side surfaces of all substrates 720 constituting the mounting substrate 72 as a multilayer substrate, and these cutouts 724 on the substrates 720 are each provided to be continuous along the thickness direction of the substrate 720. As a result, a groove-shaped cutout 724 extending along the thickness direction is formed on the inner peripheral side surface 723 of the multilayer substrate. That is, cutouts 724 are also provided on the substrate 720 that is in close contact with the heat sink 9, that is, on the substrate 720 having the second surface 722.

[0049] By forming cutouts 724 on all substrates 720 constituting the mounting substrate 72 as a multilayer substrate, it is possible to form cutouts 724 (grooves) with a length equal to the thickness of the mounting substrate 72 on the side surface of the mounting substrate 72, and to extend the length of the cutouts 724 parallel to the extension direction of the insertion tube 2. A conductive portion 725 is provided throughout the entire area of ​​the cutout 724, thereby extending the length of the conductive portion 725 parallel to the extension direction of the insertion tube 2, increasing the bonding area when the conductive portion 725 is bonded to the core wire 81 of the power line 8, and improving the bonding strength between the conductive portion 725 and the core wire 81 (power line 8).

[0050] On the contact surface 91 of the heat sink 9, which is opposite to and in close contact with the second surface 722 of the mounting substrate 72, a recess 92 is provided by removing (cutting) a portion of the edge portion. The recess 92 is formed on the contact surface 91 along the edge portion (inner periphery) of the annular hole of the heat sink 9.

[0051] The recesses 92 and conductive portions 725 are provided correspondingly, and the number of recesses 92 formed on the contact surface 91 can be the same as the number of conductive portions 725 provided on the inner peripheral side surface 723 of the mounting substrate 72. The positional correspondence between the recesses 92 and conductive portions 725 includes the area overlap between the recesses 92 and conductive portions 725 when the mounting substrate 72 is viewed horizontally, that is, in the vertical direction relative to the first surface 721 of the mounting substrate 72.

[0052] By providing a recess 92 on the contact surface 91, the conductive portion 725 of the mounting substrate 72, especially the portion of the conductive portion 725 provided on the substrate 720 having the second surface 722 (the substrate 720 located at the last end), can be reliably separated from the heat sink 9, and the insulation distance between the conductive portion 725 and the heat sink 9 can be ensured.

[0053] The recesses 92, which are used to ensure the insulation distance between the conductive part 725 and the heat sink 9, correspond to each conductive part 725 and are formed in multiples on the inner periphery of the contact surface 91, but are not limited thereto. The recesses 92 can also be formed by cutting out (cutting open) the inner periphery of the hole provided on the contact surface 91 of the heat sink 9 throughout the entire circumference.

[0054] According to this embodiment, a heat sink 9, such as a heat sink, is attached to a second surface 722 on the mounting substrate 72, located on the opposite side of the first surface 721, which serves as the mounting surface of the light-emitting element 71. A recess 92 is provided on the contact surface 91 of the heat sink 9 attached to the second surface 722, that is, on the surface of the heat sink 9 opposite to the second surface 722 (contact surface 91). By providing the recess 92 on the contact surface 91, the conductive portion 725 of the mounting substrate 72 can be separated from the heat sink 9, and the insulation of the heat sink 9 relative to the conductive portion 725 can be ensured.

[0055] It should be understood that the embodiments disclosed herein are illustrative in all respects and not restrictive. The technical features described in the various embodiments can be combined with each other, and all variations falling within the meaning and scope of the equivalents of the claims are intended to be included within the scope of this invention.

[0056] Symbol Explanation

[0057] 1 Endoscope

[0058] 10 processor devices

[0059] 2 Insertion tube

[0060] 20 Flexible parts

[0061] 21. Bend

[0062] 22 front end

[0063] 23 Connecting parts

[0064] 24 shell

[0065] 25 objective lens

[0066] 26 light matching lenses

[0067] 3 Operations Section

[0068] 30-degree bendable operating knob

[0069] 31 operation buttons

[0070] 4 universal tubes

[0071] 5 Connector Section

[0072] 6 camera elements

[0073] 7 LED modules

[0074] 71 Light-emitting elements

[0075] 711 LED pads

[0076] 72 Mounting substrate

[0077] 720 substrate

[0078] 721 Page 1

[0079] 722 Page 2

[0080] 723 Inner Peripheral Side

[0081] 724 incision site

[0082] 725 conductive parts (positive electrode side conductive parts, negative electrode side conductive parts)

[0083] 726 peripheral side

[0084] 73 holes

[0085] 8 power cords

[0086] 81 core wire

[0087] 9 heat sinks

[0088] 91 close-fitting surface

[0089] 92 recess

Claims

1. An endoscope, In an endoscope equipped with a light-emitting module assembled at the front end of the insertion tube, The light-emitting module includes a mounting substrate on which multiple light-emitting elements are mounted. The mounting substrate is annular, with a hole in its center for inserting an imaging element that uses the light-emitting element as a light source. It also has a first surface on which the light-emitting element is mounted, a side surface located at the inner periphery of the first surface, and a second surface located on the opposite side of the first surface. The mounting substrate is a multilayer substrate composed of multiple substrates stacked together. A heat sink is attached to the second surface. In the plurality of substrates of the mounting substrate, a cutout is formed on the side surface of at least a portion of the substrate including the first surface and excluding the substrate in close contact with the heat sink. A conductive portion that is in communication with the light-emitting element is provided at the cut-out portion. A power line for supplying power to the light-emitting element is connected to the conductive part. The second surface is electrically insulated from the heat sink.

2. The endoscope according to claim 1, wherein, The side surface is the inner circumferential side surface that forms the inner circumferential surface of the hole.

3. The endoscope according to claim 1 or 2, wherein, The heat sink is in close contact with the second surface, which is located on the opposite side of the first surface. A recess is provided on the contact surface of the heat sink that is in close contact with the second surface. The heat sink is separated from the conductive part through the recess.

4. The endoscope according to claim 1 or 2, wherein, The power cord extends from the processor device side connected to the endoscope. It is connected parallel to the conductive part in the extending direction of the insertion tube.

5. The endoscope according to claim 1 or 2, wherein, The conductive portion includes a positive electrode side conductive portion connected to the positive electrode side of the light-emitting element and a negative electrode side conductive portion connected to the negative electrode side of the light-emitting element. The number of negative electrode conductive parts connected to the negative electrode side is less than the number of positive electrode conductive parts connected to the positive electrode side.

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