Imaging unit, endoscope, and method for assembling imaging unit

Abstract

An imaging unit according to an embodiment comprises: a lens unit having a cylindrical lens barrel part that extends in an optical-axis direction and a lens that is held on the inner surface of the lens barrel part; and an imaging unit of cylindrical shape extending in the optical-axis direction, the imaging unit having an imaging-element-holding member attached to the lens barrel part and an imaging element held on the inner surface of the imaging-element-holding member. A pressing surface is provided at a portion of the imaging-element-holding member that is on one side with respect to a first direction and is on one side with respect to a second direction, where the first direction is a direction intersecting the optical-axis direction, and the second direction is a direction intersecting each of the optical-axis direction and the first direction. The pressing surface extends further toward the one side in the second direction with further extension toward the one side in the first direction.

Description

Imaging unit, endoscope, and method for assembling imaging unit

[0001] The present invention relates to an imaging unit, an endoscope, and a method for assembling an imaging unit.

[0002] There is known an imaging unit mounted on an endoscope, which includes a solid-state imaging element unit having a solid-state imaging element chip and a solid-state imaging element holding frame that holds the solid-state imaging element chip, and an observation optical system unit that has a plurality of lenses and is connected to the tip side of the solid-state imaging element unit (for example, Patent Document 1).

[0003] JP 2017-109054 A

[0004] In the assembly process of the imaging unit, there has been a case where the focus of the imaging unit is adjusted by adjusting the relative position in the optical axis direction between at least one lens of the observation optical system unit and the imaging element after the solid-state imaging element holding frame that holds the imaging element is fixed to a fixing jig with fastening members such as screws. In this case, the work of fixing the solid-state imaging element holding frame to the fixing jig is complicated, and there is a risk that the number of steps for assembling the imaging unit will increase.

[0005] In view of the above circumstances, an object of the present invention is to provide an imaging unit, an endoscope, and an assembling method for an imaging unit that can suppress an increase in the number of steps required for assembling the imaging unit.

[0006] In one aspect of the present invention to achieve the above-mentioned object, an imaging unit comprises a lens unit having a cylindrical lens barrel portion extending in the optical axis direction and a lens held on the inner surface of the lens barrel portion, and an imaging unit having an imaging element holding member that is cylindrical extending in the optical axis direction and attached to the lens barrel portion, and an imaging element held on the inner surface of the imaging element holding member, wherein if a direction intersecting the optical axis direction is defined as a first direction and a direction intersecting both the optical axis direction and the first direction is defined as a second direction, a pressing surface is provided on one side of the imaging element holding member in the first direction and one side of the second direction, and the pressing surface extends to one side of the second direction as it approaches one side of the first direction.

[0007] An endoscope according to one aspect of the present invention includes the imaging unit described above at the tip of an insertion section.

[0008] In one aspect of the present invention, a method for assembling an imaging unit includes: a lens unit having a cylindrical barrel portion extending in an optical axis direction and a lens held on an inner surface of the barrel portion; an imaging unit having an imaging element holding member that is cylindrical extending in the optical axis direction and attached to the barrel portion; and an imaging unit having an imaging element held on the inner surface of the imaging element holding member, the method for assembling the imaging unit includes an attachment step of attaching the imaging unit to the lens unit, and wherein, when a direction intersecting the optical axis direction is defined as a first direction and directions intersecting both the optical axis direction and the first direction are defined as second directions, the first direction of the imaging element holding member is defined as a first direction and a second direction is defined as a second direction, the first direction of the imaging element holding member is defined as a second direction. a pressing surface is provided on one side of the first direction and one side of the second direction, and the pressing surface extends to one side of the second direction as it moves toward one side of the first direction, and the attachment process includes a supporting process of supporting, on a fixing jig, a first supporting surface which is the outer surface of the image sensor holding member facing one side of the first direction, and a second supporting surface which is the outer surface of the image sensor holding member facing the other side of the second direction; a fixing process of applying pressure to the pressing surface to fix the image sensor holding member to the fixing jig; and an adjusting process of adjusting the position of at least one of the plurality of lens frames of the barrel portion in the optical axis direction.

[0009] According to the present invention, it is possible to provide an imaging unit, an endoscope, and an assembling method of an imaging unit that can suppress an increase in the number of steps required for assembling the imaging unit.

[0010] 10 is a perspective view showing an endoscope system of a first embodiment. FIG. 10 is a perspective view showing an imaging unit of the first embodiment. FIG. 10 is a cross-sectional view showing an imaging unit of the first embodiment. FIG. 10 is a perspective view showing an imaging element holding member of the first embodiment. FIG. 10 is a plan view of the imaging element holding member of the first embodiment, viewed from the base end side. FIG. 10 is a flowchart showing an attachment process of the first embodiment. FIG. 10 is a cross-sectional view showing a fixing process of the first embodiment. FIG. 10 is a perspective view showing an imaging element holding member of the second embodiment. FIG. 10 is a cross-sectional view showing a fixing process of the second embodiment. FIG. 10 is a perspective view showing an imaging element holding member of the third embodiment. FIG. 10 is a cross-sectional view showing a fixing process of the third embodiment. FIG. 10 is a perspective view showing an imaging unit of the fourth embodiment. FIG. 10 is a cross-sectional view showing a fixing process of the fourth embodiment. FIG. 10 is a perspective view showing an imaging element holding member of the fifth embodiment. FIG. 10 is a cross-sectional view showing a fixing process of the fifth embodiment. FIG. 10 is a perspective view showing an imaging unit of the sixth embodiment. FIG. 10 is a cross-sectional view showing a fixing process of the sixth embodiment. FIG. 10 is a cross-sectional view showing a fixing process of the seventh embodiment. FIG. 10 is a cross-sectional view showing a fixing process of the eighth embodiment. FIG. 10 is a cross-sectional view showing a fixing process of the ninth embodiment. FIG. 10 is a perspective view showing an imaging element holding member of the ninth embodiment. FIG. 10 is a plan view showing the fixing process of the ninth embodiment, viewed from the other side of the first direction.

[0011] An imaging unit, an endoscope, and an assembly method for an imaging unit according to embodiments of the present invention will be described below with reference to the drawings. Note that the scope of the present invention is not limited to the following embodiments and can be modified as desired within the scope of the technical concept of the present invention. In addition, in the following drawings, the scale and number of components may differ from the actual structure in order to make each component easier to understand.

[0012] In each figure, the Z axis is indicated as appropriate. The Z axis is the direction in which the optical axis J of the embodiment described below extends. The optical axis J shown in each figure as appropriate is a virtual axis. In the following description, the direction in which the optical axis J extends, i.e., the direction parallel to the Z axis, will be referred to as the "optical axis direction." The radial direction centered on the optical axis J will be simply referred to as the "radial direction." The circumferential direction centered on the optical axis J will be simply referred to as the "circumferential direction." The side of the optical axis direction toward which the arrow of the Z axis points (+Z side) is the "object side (distal side)," and the side of the optical axis direction opposite to the side toward which the arrow of the Z axis points (-Z side) is the "base end side (proximal side)." The circumferential direction is indicated by arrow θ in each figure.

[0013] In each figure, a first direction D1 is shown as appropriate. The first direction D1 is a direction that intersects with the optical axis direction. In this embodiment, the first direction D1 is perpendicular to the optical axis direction. The first direction D1 does not have to be perpendicular to the optical axis direction. In this embodiment, the first direction D1 is the up-and-down direction of the imaging unit. In the following description, the side toward which the arrow of the first direction D1 points (+D1 side) is referred to as the "lower side" or "one side of the first direction D1." The side opposite to the side toward which the arrow of the first direction D1 points (-D1 side) is referred to as the "upper side" or "other side of the first direction D1."

[0014] In each figure, the second direction D2 is indicated as appropriate. The second direction D2 is a direction that intersects with both the optical axis direction and the first direction D1. In this embodiment, the second direction D2 is perpendicular to both the optical axis direction and the first direction D1. The second direction D2 does not have to be perpendicular to at least one of the optical axis direction and the first direction D1. In this embodiment, the second direction D2 is the left-right direction of the imaging unit. In the following description, the side toward which the arrow of the second direction D2 points (the +D2 side) will be referred to as the "left side" or "one side of the second direction D2." The side opposite to the side toward which the arrow of the second direction D2 points (the -D2 side) will be referred to as the "right side" or "the other side of the second direction D2."

[0015] Note that the terms upper, lower, left, and right are simply names used to explain the relative positional relationships of each part, and the actual positional relationships may be other than those indicated by these names.

[0016] <First Embodiment> Fig. 1 is a perspective view showing an endoscopic system 1 of this embodiment. Fig. 2 is a perspective view showing an imaging unit 30 of this embodiment. Fig. 3 is a cross-sectional view showing the imaging unit 30 of this embodiment. The endoscopic system 1 shown in Fig. 1 has an endoscope 2, a light source device 3, a video processor 4, and a color monitor 5. The use of the endoscope 2 of this embodiment is not particularly limited, and may be, for example, a medical endoscope or an industrial endoscope. The endoscope 2 has an insertion section 9 that is inserted into a subject, an operation section 10 that is disposed outside the subject, and a universal cord 17 that extends from the operation section 10.

[0017] A light guide bundle (not shown), an electric cable forming an electric signal transmission path, and the like are inserted inside the universal cord 17. A scope connector 18 is provided at the rear end of the universal cord 17, which optically couples illumination light from the light source device 3 that supplies illumination light to the incident end of the light guide bundle. The electric cable inside the universal cord 17 extends inside a scope cable 19 that branches off from the scope connector 18. An electric connector unit 20 is provided at the end of the scope cable 19, which electrically connects the end of the electric cable (not shown) inside the scope cable 19 to the video processor 4. When the electric connector unit 20 is connected to the video processor 4, the image pickup element 41 of the endoscope 2 and the video processor 4 are connected so as to be able to communicate with each other via the electric cable.

[0018] The insertion section 9 has a tip section 6, a bending section 7, and a flexible tube section 8, in this order, from the object side end, which is the tip in the insertion direction into the subject, to the base side end connected to the operation section 10. A well-known tip opening, an observation window 6b, an illumination window, and the like, which are not shown, are formed on the tip surface of the tip section 6. Inside the tip section 6, an imaging unit 30 that images the subject in front of the tip section 6 is disposed at a position opposite the observation window 6b. In other words, the imaging unit 30 is disposed at the tip of the insertion section 9. The endoscope 2 includes the imaging unit 30 at the tip of the insertion section 9. A detailed configuration of the imaging unit 30 will be described later.

[0019] The object-side end of a light guide bundle that transmits illumination light is located on the back side of the illumination window. The light guide bundle is inserted into the insertion section 9, passes through the operation section 10, and extends into the universal cord 17. The proximal end of the light guide bundle is located inside the scope connector 18. When the scope connector 18 is connected to the light source device 3, illumination light from the light source device 3 is optically coupled to the light guide bundle. As a result, illumination light generated by the light source device 3 is optically transmitted to the illumination window in the distal end portion 6, and is emitted from the illumination light to the outside of the distal end portion 6.

[0020] The bending section 7 is connected to the end portion on the proximal side of the distal end section 6. The bending section 7 is tubular and bendable. The amount and direction of bending of the bending section 7 can be changed by operating the operation section 10. This allows the orientation of the distal end section 6 to be changed. The bending section 7 includes, for example, multiple nodal rings. Each nodal ring is rotatably connected to an adjacent nodal ring. In the bending section 7, two systems of operation wires including a first operation wire and a second operation wire, a light guide bundle, an electric cable, a treatment instrument channel, etc. are inserted inside the nodal rings. The operation wires extend from the bending section 7 through the inside of the flexible tube section 8 to the operation section 10.

[0021] The operation unit 10 has an operation unit main body 13 that is held by the user and is used for various operations of the endoscope 2. A bending operation unit 16, a switch unit 23, and an operation lever 24 are provided on the upper part of the operation unit main body 13. The bending operation unit 16 has operation knobs 14 and 15 that operate the amount and direction of bending of the bending portion 7. The operation knobs 14 and 15 can independently pull the first operation wire and the second operation wire, respectively.

[0022] The switch section 23 has at least one switch that is mainly used to operate the imaging function. The operation lever 24 is used to operate the adjustment amount of the focus adjustment function, magnification adjustment function, zoom variable power adjustment function, etc. of the imaging unit 30. A forceps opening 12 and a folding prevention portion 11 are provided at the bottom of the operation section main body 13. The forceps opening 12 is an opening that communicates with the proximal end of the treatment instrument channel that extends from the inside of the operation section 10 through the insertion section 9 to the distal opening of the distal end section 6. The folding prevention portion 11 connects the insertion section 9 and the operation section 10.

[0023] As described above, the imaging unit 30 is disposed at the tip of the insertion section 9. The imaging unit 30 forms an optical image of the subject. As shown in FIG. 2, the imaging unit 30 is cylindrical and extends in the optical axis direction. As shown in FIG. 3, the imaging unit 30 includes a lens unit 31, an imaging section 40, and a drive section 70. The lens unit 31 forms an optical image of the subject. The lens unit 31 is the object side (+Z side) part of the imaging unit 30. The lens unit 31 has a lens barrel section 31a and a plurality of lenses 37.

[0024] The lens barrel portion 31a has a cylindrical shape extending in the optical axis direction. The lens barrel portion 31a surrounds the optical axis J from the radially outer side. The lens barrel portion 31a holds a plurality of lenses 37, an imaging unit 40, and a drive unit 70. The lens barrel portion 31a has a first main body frame 32, a second main body frame 33, and a plurality of lens frames. The plurality of lens frames include a first lens frame 34, a movable lens frame 35, and a fixed lens frame 36.

[0025] The first main body frame 32 has a cylindrical shape extending in the optical axis direction. As shown in FIG. 2, the first main body frame 32 has a substantially cylindrical shape extending in the optical axis direction. The first main body frame 32 may have other shapes, such as a rectangular cylindrical shape extending in the optical axis direction. As shown in FIG. 3, the first main body frame 32 surrounds the optical axis J from the radially outer side. The first main body frame 32 is open on both the object side (+Z side) and the base end side (-Z side). The first main body frame 32 has a first main body portion 32a, a first annular portion 32c, and a first protrusion 32g.

[0026] The first main body portion 32a is a generally cylindrical portion extending in the optical axis direction. The first main body portion 32a is the base-end (-Z side) portion of the first main body frame 32. The base-end end of the first main body portion 32a is the base-end end of the first main body frame 32. The first annular portion 32c protrudes radially inward from the object-side (+Z side) end of the first main body portion 32a. The first annular portion 32c extends circumferentially around the inner circumferential surface of the first main body portion 32a. When viewed in the optical axis direction, the first annular portion 32c is generally annular. The first annular portion 32c is provided with a first recessed portion 32e recessed radially outward. The first recessed portion 32e is open on the base-end side. The first protruding portion 32g protrudes from the first annular portion 32c toward the object side. The first protruding portion 32g is generally cylindrical and centered on the optical axis J.

[0027] The second main body frame 33 has a substantially cylindrical shape extending in the optical axis direction with the optical axis J as its center. The second main body frame 33 may have another shape, such as a rectangular tube extending in the optical axis direction. The second main body frame 33 is open on both the object side (+Z side) and the base end side (-Z side). The second main body frame 33 is disposed inside the first main body frame 32. The second main body frame 33 has a second main body portion 33a, a second annular portion 33c, a connecting portion 33e, and a tubular portion 33g.

[0028] The second main body portion 33a has a generally cylindrical shape extending in the optical axis direction. The second main body portion 33a is the object side (+Z side) portion of the second main body frame 33. The second main body portion 33a faces the first main body portion 32a with a radial gap therebetween. The second annular portion 33c protrudes radially inward from the object side end of the second main body portion 33a. When viewed in the optical axis direction, the second annular portion 33c has a generally circular ring shape. The second annular portion 33c is fixed to the inner surface of the first recessed portion 32e of the first main body frame 32. This fixes the second main body frame 33 to the first main body frame 32.

[0029] The connecting portion 33e protrudes radially outward from the end portion on the base end side (-Z side) of the second main body portion 33a. When viewed in the optical axis direction, the connecting portion 33e has a substantially annular shape. The tube portion 33g extends from the radial outer edge of the connecting portion 33e toward the base end side. The tube portion 33g has a substantially cylindrical shape that extends in the optical axis direction with the optical axis J as its center. The base end side end of the tube portion 33g is located closer to the object side (+Z side) than the base end side end of the first main body frame 32.

[0030] The first lens frame 34 holds the first lens 37a. The first lens frame 34 is substantially cylindrical and extends in the optical axis direction with the optical axis J as its center. The first lens frame 34 is disposed closer to the object side (+Z side) than the first main body frame 32. The first lens frame 34 is open on both the object side and the base end side (-Z side). The base end side portion of the outer peripheral surface of the first lens frame 34 is fixed to the inner peripheral surface of the first protrusion 32g. This fixes the first lens frame 34 to the first main body frame 32.

[0031] The movable lens frame 35 holds the second lens 37b. The movable lens frame 35 is substantially cylindrical and extends in the optical axis direction, centered on the optical axis J. The movable lens frame 35 is open on both the object side (+Z side) and the base end side (-Z side). The movable lens frame 35 is disposed inside the second main body portion 33a. The movable lens frame 35 is provided with a protrusion 35a. The protrusion 35a protrudes radially outward from a portion of the outer circumferential surface of the movable lens frame 35 that is central in the optical axis direction. The protrusion 35a extends circumferentially along the outer circumferential surface of the movable lens frame 35. The outer circumferential surface of the protrusion 35a contacts the inner circumferential surface of the second main body portion 33a in the radial direction. In this embodiment, the movable lens frame 35 is supported by the inner circumferential surface of the second main body portion 33a so as to be movable in the optical axis direction. This allows the movable lens frame 35 to be supported by the second main body frame 33 so as to be movable in the optical axis direction.

[0032] The fixed lens frame 36 holds the third lens 37c, the fourth lens 37d, and the imaging unit 40. The fixed lens frame 36 is substantially cylindrical and extends in the optical axis direction with the optical axis J as its center. The fixed lens frame 36 is open on both the object side (+Z side) and the base end side (-Z side). The fixed lens frame 36 has a fixed main body portion 36a, a fixed annular portion 36c, and a fixed cylinder portion 36g.

[0033] The fixed main body portion 36a has a generally cylindrical shape extending in the optical axis direction with the optical axis J as its center. The fixed main body portion 36a is disposed inside the first main body portion 32a. The fixed main body portion 36a faces the first main body portion 32a with a radial gap therebetween. The object-side (+Z side) portion of the outer circumferential surface of the fixed main body portion 36a is fixed to the inner circumferential surface of the tube portion 33g of the second main body frame 33. In this embodiment, the fixed main body portion 36a is fixed to the tube portion 33g with an adhesive (not shown). This fixes the fixed lens frame 36 to the second main body frame 33. The fixed annular portion 36c has a generally circular ring shape that protrudes radially inward from the object-side edge of the fixed main body portion 36a. The fixed annular portion 36c is provided with a second recessed portion 36e recessed radially inward. The second recessed portion 36e is open to the object side. The connecting portion 33e of the second main body frame 33 is fixed to the inner surface of the second recessed portion 36e. In this way, the fixed lens frame 36 is fixed to the second main body frame 33.

[0034] The fixed cylinder portion 36g protrudes from the radial inner edge of the fixed annular portion 36c toward the object side (+Z side). The fixed cylinder portion 36g is substantially cylindrical and protrudes in the optical axis direction with the optical axis J as its center. The outer peripheral surface of the fixed cylinder portion 36g contacts the inner peripheral surface of the movable lens frame 35 in the radial direction. The fixed cylinder portion 36g supports the movable lens frame 35 so that it can move in the optical axis direction. As described above, the movable lens frame 35 is supported by the second main body frame 33 so that it can move in the optical axis direction. This allows the movable lens frame 35 to move in the optical axis direction.

[0035] The multiple lenses 37 include a first lens 37a, a second lens 37b, a third lens 37c, and a fourth lens 37d. The lenses 37 are arranged in the following order from the object side (+Z side) to the base end side (-Z side): first lens 37a, second lens 37b, third lens 37c, and fourth lens 37d. The first lens 37a is held on the inner surface of the first lens frame 34. The second lens 37b is held on the inner surface of the movable lens frame 35. The third lens 37c and the fourth lens 37d are each fixed to the inner surface of the fixed lens frame 36. As a result, each of the multiple lenses 37 is held on the inner surface of the barrel portion 31a. As described above, the movable lens frame 35 is movable in the optical axis direction. Therefore, the second lens 37b is movable in the optical axis direction together with the movable lens frame 35. The configuration of the lens unit 31 is not limited to that of the present embodiment, and for example, the number of lenses constituting the lens unit 31 may be three or less, or may be five or more. Furthermore, the shape of each lens is not limited to that of the present embodiment.

[0036] 3 converts the optical image of the subject formed by the lens unit 31 into an image signal and transmits it to the video processor 4 (see FIG. 1). The imaging unit 40 has an imaging element 41, an imaging board 42, a signal cable 44, and an imaging element holding member 50.

[0037] The imaging element 41 receives the optical image of the subject formed by the lens unit 31 and converts it into an image signal. The imaging element 41 is, for example, an image sensor such as a CCD or CMOS. The imaging element 41 is disposed closer to the proximal end (-Z side) than the lens unit 31. The light receiving surface of the imaging element 41 faces the object side (+Z side). In this embodiment, the imaging element 41 has a substantially rectangular parallelepiped shape. When viewed from the optical axis direction, the imaging element 41 has a substantially rectangular shape with two outer sides extending in a first direction D1 and the other two outer sides extending in a second direction D2. The imaging element 41 is disposed inside the imaging element holding member 50. The imaging element 41 is held on the inner surface of the imaging element holding member 50.

[0038] The imaging board 42 is connected to the imaging element 41. Electronic components (not shown) are mounted on the imaging board 42, such as a digital IC that generates a drive signal for the imaging element 41 and a capacitor that stabilizes the drive power supply for the digital IC. The imaging board 42 is disposed closer to the base end (-Z side) than the imaging element 41. A signal cable 44 is connected to the imaging board 42. This connects the imaging board 42 and the video processor 4 (see FIG. 1) so that they can communicate with each other.

[0039] The signal cable 44 communicatively connects the imaging board 42 and the video processor 4. The proximal end of the signal cable 44 is connected to the video processor 4 shown in FIG. 1. The signal cable 44 is passed through the interior of the universal cord 17 and the interior of the insertion section 9. In this embodiment, the signal cable 44 is a cable bundle formed by bundling a plurality of cables 44a. The object-side (+Z side) end of each cable 44a is joined to the imaging board 42 by, for example, soldering. The image signal converted by the imaging element 41 is transmitted to the video processor 4 via the signal cable 44, and an image of the subject is formed in the video processor 4. The image of the subject formed in the video processor 4 is displayed on the color monitor 5.

[0040] FIG. 4 is a perspective view showing the image sensor holding member 50 of this embodiment. FIG. 5 is a plan view of the image sensor holding member 50 of this embodiment, viewed from the base end side (-Z side). As shown in FIG. 4, the image sensor holding member 50 is cylindrical and extends in the optical axis direction. The image sensor holding member 50 surrounds the optical axis J. The image sensor holding member 50 is open on both the object side (+Z side) and the base end side. The image sensor holding member 50 has a tubular portion 51 and a holding portion 52. The tubular portion 51 is substantially cylindrical and extends in the optical axis direction with the optical axis J as its center. As shown in FIG. 3, the tubular portion 51 is located closer to the object side than the holding portion 52. The outer peripheral surface of the tubular portion 51 is fixed to the inner peripheral surface of the fixed main body portion 36a of the fixed lens frame 36. This allows the image sensor holding member 50 to be attached to the lens barrel portion 31a. In other words, the image sensor 40 is attached to the lens barrel portion 31a.

[0041] As shown in FIG. 4 , the holding portion 52 has a rectangular cylindrical shape extending in the optical axis direction. The holding portion 52 surrounds the optical axis J from the radially outer side. The holding portion 52 is located closer to the base end (−Z side) than the cylindrical portion 51. The holding portion 52 is connected to the cylindrical portion 51 in the optical axis direction. As shown in FIG. 5 , the holding portion 52 has a rectangular ring shape when viewed in the optical axis direction. In this embodiment, the holding portion 52 has a substantially regular rectangular ring shape. In this embodiment, the holding portion 52 has a first wall portion 53, a second wall portion 54, a third wall portion 55, a fourth wall portion 56, a first support surface 53 a, a second support surface 55 a, and a protrusion 57. The first wall portion 53 and the second wall portion 54 are formed along the horizontal pixel direction of the image sensor 41. The third wall portion 55 and the fourth wall portion 56 are formed along the vertical pixel direction of the image sensor 41.

[0042] The first wall portion 53 and the second wall portion 54 are each a portion of the holding portion 52 extending in the second direction D2. The first wall portion 53 is located below the second wall portion 54, i.e., on one side (+D1 side) in the first direction D1. In this embodiment, the thickness T1 of the first wall portion 53 is thicker than the thickness T2 of the second wall portion 54. Note that the thickness T1 of the first wall portion 53 is the maximum dimension of the first wall portion 53 in the first direction D1, and the thickness T2 of the second wall portion 54 is the maximum dimension of the second wall portion 54 in the first direction D1. The thickness T1 of the first wall portion 53 may be the same as the thickness T2 of the second wall portion 54 or may be thinner than the thickness T2 of the second wall portion 54.

[0043] The third wall portion 55 and the fourth wall portion 56 are portions of the holder 52 that extend in the first direction D1. As described above, the first wall portion 53 and the second wall portion 54 are portions of the holder 52 that extend in the second direction D2. Therefore, when viewed from the optical axis direction, the holder 52 has a rectangular ring shape, with two walls 55 and 56 extending in the first direction D1 and the other two walls 53 and 54 extending in the second direction D2. The third wall portion 55 is located to the right (-D2 side) of the fourth wall portion 56. The upper end of the third wall portion 55 is connected to the right end of the second wall portion 54, and the lower end of the third wall portion 55 is connected to the right end of the first wall portion 53. The upper end of the fourth wall portion 56 is connected to the left end of the second wall portion 54, and the lower end of the fourth wall portion 56 is connected to the left end of the first wall portion 53. In the present embodiment, the thickness T1 of the first wall portion 53 is thicker than the thickness of the third wall portion 55 and the thickness of the fourth wall portion 56. The thickness T1 of the first wall portion 53 may be the same as the thickness of the third wall portion 55 and the thickness of the fourth wall portion 56, or may be thinner than the thickness of the third wall portion 55 and the thickness of the fourth wall portion 56.

[0044] The first support surface 53a is the surface of the outer surface of the first wall portion 53 that faces downward (toward +D1). The first support surface 53a is the outer surface that faces the lower side of the image sensor holding member 50, i.e., one side in the first direction D1. The second support surface 55a is the surface of the outer surface of the third wall portion 55 that faces right (toward -D2). The second support surface 55a is the outer surface that faces the right side of the image sensor holding member 50, i.e., the other side in the second direction D2.

[0045] 3, the imaging element 41 is disposed inside the holding portion 52. The imaging element 41 is held on the inner surface of the holding portion 52. In this embodiment, the imaging element 41 is adhesively fixed to the inner surface of the holding portion 52. The imaging element 41 may be press-fitted into the inner surface of the holding portion 52, or may be fixed to the inner surface of the holding portion 52 by a fastening member such as a screw.

[0046] As shown in FIG. 4 , the protrusion 57 protrudes to the left from the fourth wall 56, i.e., to one side (+D2 side) in the second direction D2. When viewed from the optical axis direction, the protrusion 57 has a generally triangular shape protruding to the left from the fourth wall 56. The protrusion 57 is provided on the lower side of the fourth wall 56, i.e., on one side (+D1 side) in the first direction D1. The protrusion 57 is provided on one side of the image sensor holding member 50 in the first direction D1 and one side in the second direction D2. The protrusion 57 has a pressing surface 59.

[0047] In this embodiment, the pressing surface 59 is a part of the outer surface of the protrusion 57. In other words, the pressing surface 59 is provided on the holding portion 52. As shown in FIG. 5 , the pressing surface 59 is provided on the lower side of the image sensor holding member 50, i.e., on one side (+D1 side) in the first direction D1, and on the left side, i.e., on one side (+D2 side) in the second direction D2. The pressing surface 59 is a surface located on the upper side (-D1 side) of the outer surface of the protrusion 57 facing radially outward. The pressing surface 59 is an inclined surface that extends to the left as it approaches the lower side. The pressing surface 59 faces in a direction tilted from the upper side to the left.

[0048] The pressing surface 59 may be provided on the lower side (+D1 side) and the right side (-D2 side) of the image sensor holding member 50. In this case, the pressing surface 59 is an inclined surface that extends to the right as it approaches the lower side, and faces in a direction tilted from the upper side to the right.

[0049] 3 moves the movable lens frame 35 in the optical axis direction. That is, the drive unit 70 moves at least one lens frame in the optical axis direction. The drive unit 70 has a substrate support frame 71, a substrate 73, electronic components 74, and a coil unit 75.

[0050] As shown in FIG. 2, the board support frame 71 extends in the optical axis direction. When viewed in the optical axis direction, the board support frame 71 has a generally U-shape that protrudes upward (toward the -D1 side). As shown in FIG. 3, the object-side (+Z side) portion of the board support frame 71 is located between the first main body portion 32a and the fixed main body portion 36a. The object-side portion of the board support frame 71 is fixed to the outer peripheral surface of the fixed main body portion 36a. This allows the drive unit 70 to be attached to the lens barrel portion 31a. The base-end (-Z side) end of the board support frame 71 is located closer to the base end than the imaging board 42. As shown in FIG. 2, the board support frame 71 covers the upper portion of the image sensor holding member 50 from the radially outer side. This allows the drive unit 70 to cover the upper side of the image sensor holding member 50, i.e., the portion on the other side (-D1 side) of the first direction D1. The lower side (+D1 side) of the image sensor holding member 50 is exposed to the outside of the board support frame 71. As a result, the pressing surface 59 is exposed to the outside of the driving unit 70 .

[0051] As shown in FIG. 3 , the substrate 73 extends in the optical axis direction. In this embodiment, the substrate 73 is a flexible printed circuit (FPC) that is flexible in the thickness direction. As shown in FIG. 2 , the substrate 73 is fixed to the surface facing the upper side (−D1 side) of the substrate support frame 71. As shown in FIG. 3 , the base end side (−Z side) of the substrate 73 is located closer to the base end than the barrel portion 31a and is exposed to the outside of the barrel portion 31a. Multiple electronic components 74 are mounted on the base end side of the substrate 73. The multiple electronic components 74 include electronic elements such as capacitors. The object side (+Z side) of the substrate 73 is located between the first main body portion 32a and the second main body frame 33. When viewed in the radial direction, the object side portion of the substrate 73 overlaps with the second main body portion 33a and the movable lens frame 35.

[0052] The coil portion 75 is configured by winding a coil wire circumferentially around the outer circumferential surface of the second body portion 33a. The coil portion 75 is fixed to the outer circumferential surface of the second body portion 33a. The drive unit 70 has two coil portions 75. The two coil portions 75 include a first coil portion 75a and a second coil portion 75b. The first coil portion 75a is positioned closer to the object (+Z side) than the second coil portion 75b. The direction of the current flowing through the first coil portion 75a and the direction of the current flowing through the second coil portion 75b are different from each other. The first coil portion 75a and the second coil portion 75b are each electrically connected to the substrate 73. A current is supplied to each of the first coil portion 75a and the second coil portion 75b from the substrate 73.

[0053] A plurality of first magnets 81 and a plurality of second magnets 82 are fixed to the outer peripheral surface of the movable lens frame 35. In this embodiment, four first magnets 81 and four second magnets 82 are fixed to the outer peripheral surface of the movable lens frame 35. Each first magnet 81 is located closer to the object side (+Z side) than the protrusion 35a. Each first magnet 81 is arranged at approximately equal intervals along the circumferential direction. Each second magnet 82 is located closer to the base end side (-Z side) than the protrusion 35a. Each second magnet 82 is arranged at approximately equal intervals along the circumferential direction. In this embodiment, the north pole of each first magnet 81 faces radially outward, and the north pole of each second magnet 82 faces radially inward. In other words, the magnetic pole orientation of each first magnet 81 and the magnetic pole orientation of each second magnet 82 are different from each other.

[0054] When current is supplied to each of the first coil portion 75a and the second coil portion 75b by the substrate 73, the movable lens frame 35 can be moved in the optical axis direction by magnetic forces between the electromagnets formed in each coil portion 75 and the first magnets 81 and second magnets 82. In this embodiment, by appropriately changing the direction of current supplied to each coil portion 75, the movable lens frame 35 and the second lens 37b can be moved either toward the object side (+Z side) or toward the base end side (-Z side). This makes it possible to adjust the focus, magnification, and zoom of the imaging unit 30.

[0055] FIG. 6 is a flowchart showing the attachment step S1 of this embodiment. FIG. 7 is a cross-sectional view showing the fixing step S02 of this embodiment. The method for assembling the imaging unit 30 of this embodiment includes an attachment step S1 of attaching the imaging section 40 to the lens unit 31. As shown in FIG. 6 , the attachment step S1 includes a support step S01 in which the first support surface 53 a and the second support surface 55 a of the imaging element holding member 50 are supported by a fixing jig 91, a fixing step S02 in which pressure is applied to the pressing surface 59 to fix the imaging element holding member 50 to the fixing jig 91, an adjustment step S03 in which the position of the fixed lens frame 36, i.e., at least one of the multiple lens frames included in the barrel portion 31 a, in the optical axis direction is adjusted, and a second fixing step S04 in which the fixed lens frame 36 is fixed to the imaging element holding member 50. In the following description, the term "worker, etc." includes the workers performing the tasks in each step and the assembly equipment, etc. The work in each process may be performed by a worker alone, by an assembly device alone, or by a worker and an assembly device.

[0056] In the supporting step S01, the worker or the like supports each of the first supporting surface 53a and the second supporting surface 55a of the imaging element holding member 50 on a fixing jig 91. Although not shown in the drawings, the worker or the like inserts the cylindrical portion 51 of the imaging element holding member 50, to which the imaging element 41, the imaging board 42, etc. are previously fixed, into the fixed main body portion 36a of the lens unit 31, to which the drive unit 70 is previously fixed. Next, as shown in FIG. 7 , the worker or the like supports each of the first supporting surface 53a and the second supporting surface 55a of the imaging element holding member 50 on the fixing jig 91.

[0057] In this embodiment, the fixing jig 91 is substantially L-shaped when viewed from the optical axis direction. The fixing jig 91 has a first jig portion 91a and a second jig portion 91b. The first jig portion 91a is columnar and extends in the second direction D2. The first jig portion 91a is disposed on the lower side (+D1 side) of the image sensor holding member 50 and supports the first support surface 53a from below. The second jig portion 91b is columnar and protrudes upward (-D1 side) from the right end (-D2 side) of the first jig portion 91a. The second jig portion 91b is disposed on the right side of the image sensor holding member 50 and supports the second support surface 55a from the right side. As a result, the image sensor holding member 50 is supported by the fixing jig 91. When the worker or the like causes the first support surface 53a and the second support surface 55a of the imaging element holding member 50 to be supported by the fixing jig 91, the supporting step S01 is completed.

[0058] In the fixing step S02, the worker applies pressure to the pressing surface 59 to fix the image sensor holding member 50 to the fixing jig 91. The worker first places the pressing jig 92 on the left side (+D2 side) of the image sensor holding member 50. In this embodiment, the pressing jig 92 is provided with a hole 92a. The hole 92a is a hole that passes through the pressing jig 92. The hole 92a is a hole that extends in a direction inclined from the right side (-D2 side) to the downward side (+D1 side). When viewed from the direction in which the hole 92a extends, the hole 92a overlaps with the pressing surface 59. The hole 92a has a first hole 92b and a second hole 92c.

[0059] The first hole portion 92b is the portion on the left side (+D2 side) of the hole portion 92a. An internal thread is formed on the inner circumferential surface of the first hole portion 92b. The first hole portion 92b is an internally threaded hole. The second hole portion 92c is the portion on the right side (-D2 side) of the hole portion 92a. The inner diameter of the second hole portion 92c is smaller than the inner diameter of the first hole portion 92b.

[0060] Next, the operator inserts the pressure pin 94 into the hole 92a from the left side (+D2 side) of the hole 92a. At this time, the tip of the pressure pin 94 protrudes from the second hole 92c to the outside of the pressure jig 92. As described above, the pressing surface 59 is exposed to the outside of the drive unit 70. Therefore, the operator can bring the tip of the pressure pin 94 into contact with the pressing surface 59 from the outside of the drive unit 70. Next, the operator tightens the screw 93 into the first hole 92b and presses the pressure pin 94 against the pressing surface 59 with the screw 93. As a result, a pressure force F is applied to the pressing surface 59 in a direction tilted from the right side (-D2 side) to the downward side (+D1 side). At this time, a first force component F1 and a second force component F2 are applied to the image sensor holding member 50. The first force component F1 is a component of the pressure force F in the first direction D1. The first component of force F1 is a downward force. The first component of force F1 presses the first wall portion 53 against the first jig portion 91a of the fixing jig 91. In other words, the imaging element holding member 50 is pressed against the first jig portion 91a. The second component of force F2 is a component of the pressure force F in the second direction D2. The second component of force F2 is a force that is directed to the right. The second component of force F2 presses the third wall portion 55 against the second jig portion 91b of the fixing jig 91. In other words, the imaging element holding member 50 is pressed against the second jig portion 91b. As a result, the imaging element holding member 50 is fixed to the fixing jig 91. At this time, the central portions of the imaging element 41 in the first direction D1 and the second direction D2 are positioned close to the optical axis J. The worker or the like applies pressure to the pressing surface 59 to fix the image pickup element holding member 50 to the fixing jig 91, and the fixing step S02 is completed.

[0061] In the adjustment step S03, the worker adjusts the optical axis position of the fixed lens frame 36, i.e., at least one of the lens frames included in the lens barrel portion 31a. This allows the worker to adjust the optical axis positions of the third lens 37c and the fourth lens 37d (see FIG. 3) held in the fixed lens frame 36. While checking on the color monitor 5 (see FIG. 1) an image signal converted by the image sensor 41 and formed in the video processor 4 (see FIG. 1), the worker adjusts the optical axis position of the fixed lens frame 36 to adjust the focus of the image. The worker adjusts the optical axis position of the fixed lens frame 36 so that the focal position of the optical image formed by the lens unit 31 in the optical axis direction coincides with the light receiving surface of the image sensor 41. Once the worker has adjusted the optical axis position of the fixed lens frame 36, the adjustment step S03 is complete.

[0062] In the second fixing step S04, the worker fixes the fixed lens frame 36 to the imaging element holding member 50. More specifically, as shown in FIG. 3, the worker fixes the fixed lens frame 36 to the cylindrical portion 51. First, the worker adhesively fixes the fixed lens frame 36 to the second main body frame 33 using an adhesive (not shown). This determines the positions of the fixed lens frame 36, the third lens 37c, and the fourth lens 37d in the optical axis direction. Next, the worker fixes the fixed lens frame 36 to the cylindrical portion 51 of the imaging element holding member 50. In this embodiment, the worker adhesively fixes the fixed lens frame 36 to the cylindrical portion 51. This attaches the imaging unit 40 to the lens barrel portion 31a. Once the worker fixes the fixed lens frame 36 to the imaging element holding member 50, the second fixing step S04 is completed. Once the second fixing step S04 is completed, the attachment step S1 is completed. At this time, the focal position in the optical axis direction of the optical image formed by the lens unit 31 and the light receiving surface of the image sensor 41 coincide with each other.

[0063] According to this embodiment, the imaging unit 30 includes a lens unit 31 having a cylindrical lens barrel portion 31a extending in the optical axis direction and a lens 37 held on the inner surface of the lens barrel portion 31a, and an imaging section 40 having a cylindrical image sensor holding member 50 that extends in the optical axis direction and is attached to the lens barrel portion 31a, and an image sensor 41 held on the inner surface of the image sensor holding member 50. A pressing surface 59 is provided on the lower side of the image sensor holding member 50, i.e., on one side in the first direction D1 (+D1 side) and on the left side, i.e., on one side in the second direction D2 (+D2 side), and the pressing surface 59 extends leftward as it goes downward. Therefore, in the fixing step S02, by the simple task of applying pressure to the pressing surface 59 of the image sensor holding member 50 to apply a pressure force F, it is possible to apply to the image sensor holding member 50 a first component F1, which is a component of the pressure force F that faces downward, and a second component F2, which is a component of the pressure force F that faces to the right (-D2 side). This makes it possible to press the image sensor holding member 50 downward and to the right against the fixing jig 91. Therefore, in the fixing step S02, it is possible to fix the imaging unit 40 to the fixing jig 91 by the simple task of applying pressure to the pressing surface 59. This makes it possible to prevent an increase in the number of steps in the fixing step S02, and therefore to prevent an increase in the number of steps in assembling the image sensor unit 30.

[0064] According to this embodiment, the lens barrel portion 31a includes a drive unit 70 that moves the movable lens frame 35 that holds the lens 37 in the optical axis direction. The drive unit 70 covers the upper side of the image sensor holding member 50, i.e., the other side (-D1 side) in the first direction D1, and the pressing surface 59 is exposed to the outside of the drive unit 70. Therefore, as described above, in the fixing step S02, the tip of the pressure pin 94 can be brought into contact with the pressing surface 59 from outside the drive unit 70, allowing the pressure pin 94 to pressurize the pressing surface 59. This allows the pressure to be applied to the pressing surface 59 from outside the drive unit 70 in the fixing step S02. Therefore, even when the image pickup unit 30 includes the drive unit 70, the image pickup unit 40 can be fixed to the fixing jig 91 by the simple operation of applying pressure to the pressing surface 59 and applying a pressure force F. Therefore, even if the imaging unit 30 includes the drive section 70, an increase in the number of steps in the fixing step S02 can be suppressed, and therefore an increase in the number of steps in assembling the imaging unit 30 can be suppressed.

[0065] According to this embodiment, the image sensor holding member 50 has a cylindrical holding portion 52 extending in the optical axis direction, the image sensor 41 is held on the inner surface of the holding portion 52, and the pressing surface 59 is provided on the holding portion 52. Therefore, it is easy to shorten the distance in the optical axis direction between the image sensor 41 and the pressing surface 59, and therefore it is easy to accurately determine the position of the image sensor 41 in the first direction D1 and the position of the image sensor 41 in the second direction D2 relative to the fixing jig 91 in the fixing step S02. This makes it easy to reduce the amount of misalignment between the center of the image sensor 41 and the optical axis J in the direction perpendicular to the optical axis direction. Therefore, the quality of the image of the subject formed by the endoscope 2 can be improved.

[0066] According to this embodiment, the holding portion 52 has a protruding portion 57 that protrudes to the left, i.e., one side (+D2 side) in the second direction D2, and the pressing surface 59 is part of the outer surface of the protruding portion 57. Therefore, since the pressing surface 59 is located to the left of the fourth wall portion 56, when the pressing pin 94 presses the pressing surface 59 in the fixing step S02, it is easy to prevent the tip of the pressing pin 94 from coming into contact with the fourth wall portion 56. This makes it easy to press the pressing surface 59 with the pressing pin 94 in the fixing step S02, which more effectively prevents an increase in the number of steps required for the fixing step S02. Therefore, it is more effectively possible to more effectively prevent an increase in the number of steps required for assembling the imaging unit 30.

[0067] According to this embodiment, the holding portion 52 has a first wall portion 53 and a second wall portion 54 extending in the second direction D2 and formed along the horizontal pixel direction of the image sensor 41. The first wall portion 53 is located below the second wall portion 54, i.e., on one side (+D1 side) in the first direction D1, and the thickness T1 of the first wall portion 53 is thicker than the thickness T2 of the second wall portion 54. This makes it easy to prevent the thickness T1 of the first wall portion 53 pressed by the fixing jig 91 from becoming too thin. Therefore, even if a reaction force of the first component force F1 is applied to the first wall portion 53 in the fixing step S02, deformation of the first wall portion 53 can be prevented. This allows the position of the image sensor 41 relative to the fixing jig 91 to be determined with greater precision. Therefore, after adjusting the distance in the optical axis direction between the image sensor 41 and the third lens 37c and the fourth lens 37d in the adjustment step S03, it is possible to suppress fluctuations in the distance in the optical axis direction between the image sensor 41 and the third lens 37c and the fourth lens 37d when the fixing jig 91 is removed from the image sensor holding member 50. Therefore, it is possible to suppress deviations in the focus of the image of the subject formed by the endoscope 2, and it is possible to more suitably improve the quality of the image of the subject formed by the endoscope 2.

[0068] According to this embodiment, the endoscope 2 includes the imaging unit 30 at the tip of the insertion section 9. As described above, in the endoscope 2 of this embodiment, in the fixing step S02, the imaging section 40 can be fixed to the fixing jig 91 by the simple operation of applying pressure to the pressing surface 59 of the imaging element holding member 50 to apply the pressure force F. Therefore, an increase in the number of steps in the fixing step S02 can be suppressed, and therefore an increase in the number of steps for assembling the imaging unit 30 can be suppressed.

[0069] According to this embodiment, the assembly method of the imaging unit 30 includes an attachment step S1 of attaching the imaging section 40 to the lens unit 31, and the attachment step S1 includes a support step S01 of supporting the underside of the imaging element holding member 50, i.e., the first support surface 53a which is the outer surface facing one side (+D1 side) in the first direction D1, and the right side of the imaging element holding member 50, i.e., the second support surface 55a which is the outer surface facing the other side (-D2 side) in the second direction D2, on a fixing jig 91; a fixing step S02 of applying pressure to the pressing surface 59 to fix the imaging element holding member 50 to the fixing jig 91; and an adjustment step S03 of adjusting the position of the fixed lens frame 36, i.e., at least one of the multiple lens frames of the barrel portion 31a, in the optical axis direction. Therefore, as described above, in the fixing step S02, the imaging unit 40 can be fixed to the fixing jig 91 by the simple operation of applying pressure to the pressing surface 59 of the imaging element holding member 50 to apply the pressure force F. Therefore, an increase in the number of steps in the fixing step S02 can be suppressed, and therefore an increase in the number of steps for assembling the imaging unit 30 can be suppressed.

[0070] Second Embodiment Fig. 8 is a perspective view showing an image sensor holding member 250 of this embodiment. Fig. 9 is a cross-sectional view showing a fixing step S02 of this embodiment. In the following description, components identical to those of the first embodiment described above are denoted by the same reference numerals, and description thereof will be omitted. The image sensor unit 230 of this embodiment includes a lens unit 31, an image sensor 240, and a drive unit 70. The image sensor 240 of this embodiment includes an image sensor 41, an image sensor board 42, a signal cable 44, and an image sensor holding member 250.

[0071] 8, the image sensor holding member 250 is cylindrical and extends in the optical axis direction. The image sensor holding member 250 surrounds the optical axis J. The image sensor holding member 250 is open on both the object side (+Z side) and the base end side (-Z side). The image sensor holding member 250 has a cylindrical portion 51 and a holding portion 252.

[0072] The holding portion 252 has a rectangular cylindrical shape extending in the optical axis direction. The holding portion 252 surrounds the optical axis J from the radially outer side. As shown in FIG. 9 , the holding portion 252 has a substantially regular rectangular ring shape when viewed in the optical axis direction. In this embodiment, a recess 258 is provided in the holding portion 252. The recess 258 is a recess recessed from the surface facing the left side (+D2 side) of the fourth wall portion 56 to the right side (-D2 side). That is, the recess 258 is recessed from the left side of the outer surface of the holding portion 252, i.e., the surface facing one side in the second direction D2, to the right side, i.e., the other side in the second direction D2. In this embodiment, the recess 258 penetrates the fourth wall portion 56. The recess 258 may have a bottom surface, in which case the recess 258 does not penetrate the fourth wall portion 56. The recess 258 has a pressing surface 259.

[0073] As shown in FIG. 8 , in this embodiment, the pressing surface 259 is part of the inner surface of the recess 258. That is, the pressing surface 259 is provided on the holding portion 252. As shown in FIG. 9 , the pressing surface 259 is provided on the lower side of the image sensor holding member 250, i.e., on one side (+D1 side) in the first direction D1, and on the left side, i.e., on one side (+D2 side) in the second direction D2. The pressing surface 259 is an inclined surface that extends leftward as it approaches the lower side. The pressing surface 259 faces in a direction inclined from the upper side to the left. The pressing surface 259 is exposed to the outside of the drive unit 70. Other configurations of the image capturing unit 240 of this embodiment are similar to those of the image capturing unit 40 of the first embodiment described above.

[0074] Next, the fixing step S02 of this embodiment will be described. As shown in FIG. 9 , an operator inserts the pressure pin 94 into the hole 92a from the left side (+D2 side) of the hole 92a. As described above, the pressing surface 259 is exposed to the outside of the drive unit 70, so the operator can bring the tip of the pressure pin 94 into contact with the pressing surface 259 from outside the drive unit 70. Next, the operator tightens the screw 93 into the first hole 92b, and the screw 93 presses the pressure pin 94 against the pressing surface 259. As a result, a pressure force F is applied to the pressing surface 259 in a direction tilted from the right side (-D2 side) to the downward side (+D1 side). At this time, as in the first embodiment described above, a first component force F1 and a second component force F2 are applied to the image sensor holding member 250, and the image sensor holding member 250 is fixed to the fixing jig 91. The fixing step S02 is completed when the worker applies pressure to the pressing surface 259 to fix the image pickup element holding member 250 to the fixing jig 91. The other operations in the attachment step S1 of this embodiment are the same as the other operations in the attachment step S1 of the first embodiment described above.

[0075] According to this embodiment, the holding portion 252 is provided with a recess 258 that is recessed from the left side of the outer surface of the holding portion 252, i.e., the surface facing one side (+D2 side) in the second direction D2, to the right side, i.e., the other side (-D2 side) in the second direction D2, and the pressing surface 259 is part of the inner surface of the recess 258. Therefore, compared to when the pressing surface 259 is provided on a portion that protrudes outward from the holding portion 252, for example, it is possible to prevent the image sensor holding member 250 from increasing in size in the direction perpendicular to the optical axis direction. Therefore, it is possible to prevent the image pickup unit 230 from increasing in size in the direction perpendicular to the optical axis direction.

[0076] Furthermore, in this embodiment, the pressing surface 259 is exposed to the outside of the drive unit 70. Therefore, similar to the first embodiment described above, even if the imaging unit 230 includes the drive unit 70, the imaging unit 240 can be fixed to the fixing jig 91 by the simple operation of applying pressure to the pressing surface 259 and applying the pressure force F in the fixing step S02. Therefore, even if the imaging unit 230 includes the drive unit 70, an increase in the number of steps in the fixing step S02 can be suppressed, and therefore an increase in the number of steps in assembling the imaging unit 230 can be suppressed.

[0077] Third Embodiment Fig. 10 is a perspective view showing an image sensor holding member 350 of this embodiment. Fig. 11 is a cross-sectional view showing a fixing step S02 of this embodiment. In the following description, components identical to those of the first embodiment described above are denoted by the same reference numerals, and description thereof will be omitted. The image sensor unit 330 of this embodiment includes a lens unit 31, an image sensor 340, and a drive unit 70. The image sensor 340 of this embodiment includes an image sensor 41, an image sensor board 42, a signal cable 44, and an image sensor holding member 350.

[0078] 10 , the image sensor holding member 350 is cylindrical and extends in the optical axis direction. The image sensor holding member 350 surrounds the optical axis J. The image sensor holding member 350 is open on both the object side (+Z side) and the base end side (−Z side). The image sensor holding member 350 has a cylindrical portion 51 and a holding portion 352.

[0079] The holding portion 352 has a rectangular cylindrical shape extending in the optical axis direction. The holding portion 352 surrounds the optical axis J from the radially outer side. Although not shown, the holding portion 352 has a substantially regular rectangular ring shape when viewed in the optical axis direction. The holding portion 352 has a protruding portion 357. The protruding portion 357 protrudes to the left from the fourth wall portion 56, i.e., to one side (+D2 side) in the second direction D2. The protruding portion 357 is provided on the lower side (+D1 side) and left side of the image sensor holding member 350. The protruding portion 357 has a protruding inclined surface 357a and a recessed portion 358.

[0080] The protruding inclined surface 357a is a part of the outer surface of the protruding portion 357. The protruding inclined surface 357a is a surface located on the upper side (-D1 side) of the outer surface of the protruding portion 357 facing radially outward. The protruding inclined surface 357a is an inclined surface that extends downward, i.e., toward one side (+D1 side) in the first direction D1, and then to the left, i.e., toward one side (+D2 side) in the second direction D2. The protruding inclined surface 357a faces in a direction tilted from the upper side to the left. The recess 358 is recessed from the protruding inclined surface 357a in a direction opposite to the direction in which the protruding inclined surface 357a faces. The recess 358 is a recess that is recessed in a direction tilted from the lower side to the right.

[0081] In this embodiment, the image sensor holding member 350 is provided with a plurality of pressing surfaces 359. Each pressing surface 359 is provided on the lower, left side of the image sensor holding member 350. Each pressing surface 359 is an inclined surface that extends to the left as it approaches the lower side. Each pressing surface 359 faces in a direction that is inclined from the upper side to the left side. Although not shown in the figure, each pressing surface 359 is exposed to the outside of the drive unit 70. The plurality of pressing surfaces 359 includes a first pressing surface 359a and a second pressing surface 359c.

[0082] As shown in FIG. 11 , the first and second pressing surfaces 359a and 359c are each the inner surface of the recess 358. The first pressing surface 359a is the surface of the inner surface of the recess 358 facing the object side (+Z side). The second pressing surface 359c is the surface of the inner surface of the recess 358 facing the base end side (-Z side). The first and second pressing surfaces 359a and 359c face each other in the optical axis direction. The first pressing surface 359a is an inclined surface that extends toward the object side as it moves toward the right (-D2 side). The second pressing surface 359c is an inclined surface that extends toward the base end as it moves toward the right. Therefore, the distance between the first and second pressing surfaces 359a and 359c in the optical axis direction becomes smaller as it moves toward the right. Other configurations of the imaging unit 340 of this embodiment are similar to other configurations of the imaging unit 40 of the first embodiment described above.

[0083] Next, the fixing step S02 of this embodiment will be described. As shown in FIG. 11 , similar to the first embodiment described above, an operator tightens screws (not shown) into the first holes and uses the screws to pressurize the pressure pins 94 against the pressing surfaces 359. As a result, a pressure force F is applied to each pressing surface 359 in a direction tilted from the right side (−D2 side) to the downward side (+D1 side). Although not shown, a first component F1 of the pressure force F, which is directed downward, and a second component F2 of the pressure force F, which is directed rightward, are applied to the image sensor holding member 350, similar to the first embodiment described above. As a result, the image sensor holding member 350 is fixed to the fixing jig 91. Furthermore, in this embodiment, as described above, the first pressing surface 359a is an inclined surface that extends toward the object side (+Z side) as it approaches the right, so that a third component F3, which is a component of the pressure force F that faces the base end side (-Z side), is applied to the first pressing surface 359a. The second pressing surface 359c is an inclined surface that extends toward the base end side as it approaches the right, so that a fourth component F4, which is a component of the pressure force F that faces toward the object side, is applied to the second pressing surface 359c. As a result, the third and fourth components F3 and F4, which face in opposite directions in the optical axis direction, are applied to the image sensor holding member 350. Therefore, in the fixing step S02 of this embodiment, the image sensor holding member 350 can be fixed at a position in the optical axis direction where the third and fourth components F3 and F4 are balanced. The fixing step S02 is completed when the worker applies pressure to the pressing surface 359 to fix the image pickup element holding member 350 to the fixing jig 91. The other operations in the attachment step S1 of this embodiment are the same as the other operations in the attachment step S1 of the first embodiment described above.

[0084] According to this embodiment, the image sensor holding member 350 is provided with a plurality of pressing surfaces 359, including a first pressing surface 359 a and a second pressing surface 359 c, each of which is an inner surface of the recess 358 and faces each other in the optical axis direction, and the distance in the optical axis direction between the first pressing surface 359 a and the second pressing surface 359 c decreases toward the right, i.e., toward the other side (−D2 side) in the second direction D2. Therefore, as described above, in the fixing step S02, the image sensor holding member 350 can be fixed to a position in the optical axis direction where the third component of force F3 and the fourth component of force F4 are balanced by the simple operation of applying pressure to the first pressing surface 359 a and the second pressing surface 359 c with the pressure pin 94. This makes it possible to preferably suppress fluctuations in the optical axis direction position of the image sensor 41 held by the image sensor holding member 350 in the adjustment step S03. Therefore, it is possible to preferably suppress fluctuations in the optical axis direction distances between the image sensor 41 and the third lens 37c and the fourth lens 37d in the adjustment step S03. This makes it easier to adjust the optical axis direction position of the fixed lens frame 36, thereby suppressing an increase in the number of steps required for the adjustment step S03. Therefore, it is possible to more preferably suppress an increase in the number of steps required for assembling the image sensor unit 330.

[0085] Fourth Embodiment Fig. 12 is a perspective view showing an imaging section 440 of this embodiment. Fig. 13 is a cross-sectional view showing a fixing step S02 of this embodiment. In the following description, components identical to those of the first embodiment described above are denoted by the same reference numerals, and description thereof will be omitted. The imaging unit 430 of this embodiment includes a lens unit 31, an imaging section 440, and a drive section 70. The imaging section 440 of this embodiment includes an imaging element 41, an imaging board 42, a signal cable 44, and an imaging element holding member 450.

[0086] 12 , the image sensor holding member 450 is cylindrical and extends in the optical axis direction. The image sensor holding member 450 surrounds the optical axis J. The image sensor holding member 450 is open on both the object side (+Z side) and the base end side (−Z side). The image sensor holding member 450 has a cylindrical portion 51, a holding portion 452, and a protruding portion 457.

[0087] The holding portion 452 is cylindrical and extends in the optical axis direction. The holding portion 452 surrounds the optical axis J from the radially outer side. The image pickup element 41 is held on the inner surface of the holding portion 452. The protruding portion 457 protrudes from a lower portion of the holding portion 452 toward the base end side (-Z side). In this embodiment, the protruding portion 457 is in the shape of a substantially square pillar that protrudes in the optical axis direction. The protruding portion 457 is provided on the lower portion of the image pickup element holding member 450. Although not shown in the drawings, the protruding portion 457 is exposed to the outside of the drive unit 70. The protruding portion 457 has a pressing surface 459.

[0088] The pressing surface 459 is a part of the outer surface of the protrusion 457. The pressing surface 459 is the surface of the outer surface of the protrusion 457 facing the left side (+D2 side). The pressing surface 459 is provided on the lower, left side of the image sensor holding member 450. The pressing surface 459 is an inclined surface that extends downward, i.e., toward one side (+D1 side) in the first direction D1, and then to the left side, i.e., toward one side (+D2 side) in the second direction D2. The pressing surface 459 faces in a direction inclined from the upper side to the left side. Although not shown, the pressing surface 459 is exposed to the outside of the drive unit 70. Other configurations of the image capturing unit 440 of this embodiment are similar to other configurations of the image capturing unit 40 of the first embodiment described above.

[0089] Next, the mounting step S1 of this embodiment will be described. In the supporting step S01, an operator or the like supports the downward (+D1 side) and right (-D2 side) surfaces of the protrusion 457 of the image sensor holding member 450 on a fixing jig 491. As shown in FIG. 13 , in this embodiment, the fixing jig 491 is substantially L-shaped when viewed from the optical axis direction. The fixing jig 491 has a first jig portion 491a and a second jig portion 491b. The first jig portion 491a is columnar and extends in the second direction D2. The first jig portion 491a is disposed below the protrusion 457 and supports the downward surface of the protrusion 457 from below. The second jig portion 491b is columnar and protrudes upward (-D1 side) from the right end of the first jig portion 491a. The second jig portion 491b is disposed on the right side of the protruding portion 457, and supports, from the right side, the surface of the protruding portion 457 that faces right. In this way, the imaging element holding member 450 is supported by the fixing jig 491. When the worker or the like causes the fixing jig 491 to support the imaging element holding member 450, the supporting step S01 is completed.

[0090] In the fixing step S02, the worker applies pressure to the pressing surface 459 to fix the image pickup element holding member 450 to the fixing jig 491. The pressing jig 492 is provided with a hole 492a. The hole 492a is a hole that penetrates the pressing jig 492 in the second direction D2. When viewed from the second direction D2, the hole 492a overlaps with the pressing surface 459. The hole 492a has a first hole 492b and a second hole 492c. The first hole 492b is located on the left side (+D2 side) of the hole 492a. A female thread is formed on the inner circumferential surface of the first hole 492b. The second hole 492c is located on the right side (-D2 side) of the hole 492a.

[0091] Next, the operator inserts the pressure pin 94 into the hole 492a from the left side (+D2 side) of the hole 492a and brings the tip of the pressure pin 94 into contact with the pressing surface 459. Next, the operator tightens the screw 93 into the first hole 492b and applies pressure to the pressing surface 459 with the pressure pin 94. This applies a pressure force F to the right side (-D2 side) of the pressing surface 459. At this time, a first component F1, which is a component of the pressure force F that faces downward, and a second component F2, which is a component of the pressure force F that faces right, are applied to the protrusion 457. This fixes the protrusion 457 to the fixing jig 491. In other words, the image sensor holding member 450 is fixed to the fixing jig 491. The worker or the like applies pressure to the pressing surface 459 to fix the image pickup element holding member 450 to the fixing jig 491, and the fixing step S02 is completed.

[0092] The operations of the adjusting step S03 and the second fixing step S04 of this embodiment are the same as those of the adjusting step S03 and the second fixing step S04 of the first embodiment. When the second fixing step S04 is completed, the mounting step S1 is completed. At this time, the focal position in the optical axis direction of the optical image formed by the lens unit 31 and the light receiving surface of the image sensor 41 are aligned with each other.

[0093] According to this embodiment, the image sensor holding member 450 has a cylindrical holding portion 452 extending in the optical axis direction and a protruding portion 457 protruding from the holding portion 452 toward the base end (-Z side), the image sensor 41 is held on the inner surface of the holding portion 452, and the pressing surface 459 is part of the outer surface of the protruding portion 457. Therefore, compared to a case where the pressing surface 459 is provided on a portion of the holding portion 452 that protrudes outward, for example, it is possible to prevent the image sensor holding member 450 from increasing in size in the direction perpendicular to the optical axis direction. Therefore, it is possible to prevent the image sensor unit 430 from increasing in size in the direction perpendicular to the optical axis direction.

[0094] Furthermore, in the present embodiment, in the fixing step S02, the protruding portion 457 is pressed by the pressure pin 94. Therefore, compared to when the holding portion 452 is pressed by the pressure pin 94, the stress applied to the holding portion 452 can be reduced. This reduces the stress applied to the image pickup element 41 held by the holding portion 452, and therefore, damage to the image pickup element 41 in the fixing step S02 can be suppressed. Therefore, the reliability of the operation of the endoscope 2 can be improved.

[0095] Furthermore, in this embodiment, as described above, the pressing surface 459 is exposed to the outside of the drive unit 70. Therefore, similar to the first embodiment described above, even when the imaging unit 430 includes the drive unit 70, the imaging unit 440 can be fixed to the fixing jig 491 by the simple operation of applying pressure to the pressing surface 459 to apply the pressure force F. Therefore, even when the imaging unit 430 includes the drive unit 70, an increase in the number of steps in the fixing step S02 can be suppressed, and therefore an increase in the number of steps in assembling the imaging unit 430 can be suppressed.

[0096] Fifth Embodiment Fig. 14 is a perspective view showing an image sensor holding member 550 of this embodiment. Fig. 15 is a perspective view showing a fixing step S02 of this embodiment. In the following description, the same components as those in the first embodiment described above are denoted by the same reference numerals, and their description will be omitted. The image sensor unit 530 of this embodiment includes a lens unit 31, an image sensor 540, and a drive unit 70. The image sensor 540 of this embodiment includes an image sensor 41, an image sensor board 42, a signal cable 44, and an image sensor holding member 550.

[0097] 14, the image sensor holding member 550 is cylindrical and extends in the optical axis direction. The image sensor holding member 550 surrounds the optical axis J. The image sensor holding member 550 is open on both the object side (+Z side) and the base end side (-Z side). The image sensor holding member 550 has a cylindrical portion 51, a holding portion 552, and a protruding portion 557.

[0098] The holding portion 552 is cylindrical and extends in the optical axis direction. The holding portion 552 surrounds the optical axis J from the radially outer side. Although not shown, the image pickup element 41 is held on the inner surface of the holding portion 552. The protrusion 557 protrudes from a lower portion of the holding portion 552 toward the base end side (-Z side). The protrusion 557 is provided on a lower portion of the image pickup element holding member 550. Although not shown, the protrusion 557 is exposed to the outside of the drive unit 70. The protrusion 557 has a pressing surface 559.

[0099] The pressing surface 559 is a part of the outer surface of the protrusion 557. The pressing surface 559 is provided on the lower, left side of the image sensor holding member 550. The pressing surface 559 is an inclined surface that extends to the left (+D2 side) as it approaches the lower side (+D1 side). Furthermore, the pressing surface 559 is an inclined surface that extends downward as it approaches the base end side (-Z side). In this embodiment, the pressing surface 559 faces in a direction that is inclined from the upper side toward the left side and the base end side. Although not shown in the figure, the pressing surface 559 is exposed to the outside of the drive unit 70. Other configurations of the image capturing unit 540 of this embodiment are similar to other configurations of the image capturing unit 40 of the first embodiment described above.

[0100] Next, the fixing step S02 of this embodiment will be described. As shown in FIG. 15 , in the fixing step S02, an operator or the like applies pressure to the pressing surface 559 using the pressure pin 94. Preferably, the operator or the like presses the pressure pin 94 against the pressing surface 559 in a direction perpendicular to the pressing surface 559. As a result, a pressure force F (not shown) is applied to the pressing surface 559 in a direction tilted from the bottom (+D1 side) toward the right side (-D2 side) and the object side (+Z side). At this time, a first component F1 of the pressure force F, which faces downward, and a second component F2 of the pressure force F, which faces right, are applied to the protrusion 557, thereby fixing the image sensor holding member 550 to the fixing jig 491. Furthermore, in this embodiment, a third component F3 of the pressure force F, which faces toward the object side, is applied to the protrusion 557. Although not shown, in the fixing step S02 of this embodiment, an operator or the like places a support jig (not shown) that supports the third support surface 552a, which is the surface of the holder 552 facing the object side, in the optical axis direction. Therefore, when the pressure pin 94 applies pressure to the pressing surface 559, the third support surface 552a is pressed against the support jig by the third component force F3. This makes it possible to accurately determine the position of the image sensor holding member 550 in the optical axis direction. The other operations, etc. in the attachment step S1 of this embodiment are the same as the other operations, etc. in the attachment step S1 of the first embodiment described above.

[0101] According to this embodiment, the pressing surface 559 extends downward, i.e., toward one side (+D1 side) in the first direction D1, as it approaches the base end (-Z side). Therefore, as described above, in the fixing step S02, the simple operation of applying pressure to the pressing surface 559 with the pressure pin 94 allows the image sensor holding member 550 to be fixed to the fixing jig 491, and the position of the image sensor holding member 550 in the optical axis direction to be accurately determined. This effectively prevents fluctuations in the position of the image sensor 41 held by the image sensor holding member 550 in the optical axis direction in the adjustment step S03. Therefore, this effectively prevents fluctuations in the distances in the optical axis direction between the image sensor 41 and the third and fourth lenses 37c and 37d in the adjustment step S03. This makes it easier to adjust the position of the fixed lens frame 36 in the optical axis direction, thereby preventing an increase in the number of steps required for the adjustment step S03. Therefore, this effectively prevents an increase in the number of steps required for assembling the image sensor unit 530.

[0102] Sixth Embodiment FIG. 16 is a perspective view showing an imaging unit 640 of this embodiment. FIG. 17 is a cross-sectional view showing a fixing step S02 of this embodiment. In the following description, components identical to those of the first embodiment described above are designated by the same reference numerals, and their description will be omitted. The imaging unit 630 of this embodiment includes a lens unit 31, an imaging unit 640, and a driving unit 70. As in the first embodiment described above, the lens unit 31 includes a cylindrical lens barrel 31a that surrounds the optical axis J and extends in the optical axis direction, and multiple lenses 37 held on the inner surface of the lens barrel 31a. Also, as in the first embodiment described above, the driving unit 70 moves the movable lens frame 35, i.e., at least one of the multiple lens frames included in the lens barrel 31a, in the optical axis direction. Although not shown, the driving unit 70 covers the upper side of the imaging element holding member 650, i.e., the other side (+D1 side) of the first direction D1. The imaging section 640 of this embodiment has the imaging element 41 , an imaging element fixing section 642 , a signal cable 44 , an optical element 643 , and an imaging element holding member 650 .

[0103] In this embodiment, the light receiving surface of the image sensor 41 faces upward (-D1 side). The optical element 643 is disposed above the image sensor 41. The optical element 643 reflects, downward (+D1 side), the optical image of the subject that passes through the inside of the cylindrical portion 51 and travels toward the base end side (-Z side). As a result, the optical image of the subject is incident on the light receiving surface of the image sensor 41. In other words, the optical element 643 causes light rays to be incident on the image sensor 41. In this embodiment, the optical element 643 is, for example, a prism.

[0104] The imaging element fixing portion 642 is plate-shaped and extends in a direction perpendicular to the first direction D1. When viewed from the first direction D1, the imaging element fixing portion 642 is substantially rectangular with its long sides extending in the optical axis direction. The object side (+Z side) portion of the imaging element fixing portion 642 is located lower (+D1 side) than the imaging element 41. The imaging element 41 is fixed to the surface of the imaging element fixing portion 642 facing upward (-D1 side). In this embodiment, the imaging element fixing portion 642 is an imaging board. Multiple cables 44a are connected to the base end side (-Z side) of the imaging element fixing portion 642. This electrically connects the imaging element 41 and the signal cable 44. The imaging element 41 is communicatively connected to the video processor 4 (see FIG. 1) via the signal cable 44. A pressing surface 659 is provided on the imaging element fixing portion 642.

[0105] In this embodiment, the pressing surface 659 is part of the outer surface of the image sensor fixing portion 642. The pressing surface 659 is provided on the left side (+D2 side) of the image sensor fixing portion 642. The pressing surface 659 is an inclined surface that extends leftward, i.e., to one side in the second direction D2, as it approaches downward, i.e., to one side in the first direction D1 (+D1 side). The pressing surface 659 faces in a direction that is inclined from the upper side to the left. Although not shown in the figure, the pressing surface 659 is exposed to the outside of the drive unit 70.

[0106] The image sensor holding member 650 has a cylindrical shape extending in the optical axis direction. The image sensor holding member 650 surrounds the optical axis J from the radially outer side. The image sensor holding member 650 has a cylindrical portion 51, a first portion 652, and a second portion 653. Although not shown, similar to the first embodiment described above, the cylindrical portion 51 is fixed to the fixed main body portion 36a of the fixed lens frame 36. This allows the image sensor holding member 650 to be attached to the lens barrel portion 31a. In other words, the image sensor 640 is attached to the lens barrel portion 31a.

[0107] The first portion 652 has a generally rectangular cylindrical shape that protrudes in the optical axis direction. The first portion 652 surrounds the optical axis J from the radially outer side. The first portion 652 is located closer to the base end (-Z side) than the cylindrical portion 51. The first portion 652 is connected to the cylindrical portion 51 in the optical axis direction. The imaging element fixing portion 642 is fixed to the lower side (+D1 side) of the surface of the first portion 652 that faces the base end. In this way, the imaging element holding member 650 holds the imaging element fixing portion 642.

[0108] The second portion 653 protrudes from the upper side (-D1 side) of the first portion 652 toward the base end. The second portion 653 has a generally rectangular cylindrical shape extending in the first direction D1. The second portion 653 is open on the upper and lower sides (+D1 side). The second portion 653 is located above the imaging element fixing portion 642. An optical element 643 is housed inside the second portion 653. The optical element 643 is fixed to the inner surface of the second portion 653. Other configurations of the imaging unit 640 of this embodiment are similar to other configurations of the imaging unit 40 of the first embodiment described above.

[0109] Next, the fixing step S02 of this embodiment will be described. As shown in FIG. 17 , in the fixing step S02, an operator applies pressure to the pressing surface 659 using a pressure pin 94. In this embodiment, the fixing jig 691 is generally L-shaped when viewed from the optical axis direction. The fixing jig 691 has a first jig portion 691a and a second jig portion 691b. The first jig portion 691a is columnar and extends in the second direction D2. The first jig portion 691a is disposed below the image sensor fixing portion 642 and supports the surface of the image sensor fixing portion 642 facing downward from below. The second jig portion 691b is columnar and protrudes upward (toward the −D1 direction) from the right end of the first jig portion 691a. The second jig part 691b is disposed on the right side (-D2 side) of the imaging element fixing part 642, and supports, from the right side, the surface of the imaging element fixing part 642 that faces right. In this way, the imaging element fixing part 642 is supported by the fixing jig 691.

[0110] When an operator or the like applies pressure to the pressing surface 659 using the pressure pin 94, a pressure force F is applied to the pressing surface 659 in a direction tilted from the downward side (+D1 side) to the right side (-D2 side). At this time, a first component force F1 of the components of the pressure force F that faces downward and a second component force F2 of the components of the pressure force F that faces right side are applied to the imaging element fixing portion 642, so that the imaging element fixing portion 642 is fixed to the fixing jig 691. As a result, the imaging unit 640 is fixed to the fixing jig 691. When the operator or the like applies pressure to the pressing surface 659 to fix the imaging element fixing portion 642 to the fixing jig 691, the fixing step S02 is completed. Other tasks in the mounting step S1 of this embodiment are similar to the other tasks in the mounting step S1 of the first embodiment described above.

[0111] According to this embodiment, the imaging unit 630 includes a lens unit 31 having a cylindrical lens barrel 31a extending in the optical axis direction and a lens 37 held on the inner surface of the lens barrel 31a, and an imaging section 640 having an imaging element 41 and an imaging element fixing section 642 to which the imaging element 41 is fixed. The imaging element fixing section 642 is provided with a pressing surface 659 extending downward, i.e., toward one side (+D1 side) in the first direction D1, and then toward the left side, i.e., toward one side (+D2 side) in the second direction D2. Therefore, as described above, in the fixing step S02, the imaging element fixing section 642 can be fixed to the fixing jig 691 by the simple operation of applying pressure to the pressing surface 659 of the imaging element fixing section 642 to apply the pressure force F. In other words, the imaging section 640 can be fixed to the fixing jig 691 by the simple operation of applying pressure to the pressing surface 659. Therefore, an increase in the number of steps in the fixing step S02 can be suppressed, and therefore an increase in the number of steps in assembling the imaging unit 630 can be suppressed.

[0112] According to this embodiment, the imaging section 640 has a cylindrical imaging element holding member 650 extending in the optical axis direction, the imaging element holding member 650 holds the imaging element fixing section 642, the driving section 70 covers the upper side of the imaging element holding member 650, i.e., the other side (-D1 side) in the first direction D1, and the pressing surface 659 is exposed to the outside of the driving section 70. Therefore, even when the imaging unit 630 includes the driving section 70, the imaging section 640 can be fixed to the fixing jig 691 as described above by the simple operation of applying pressure to the pressing surface 659 to apply the pressure force F. Therefore, even when the imaging unit 630 includes the driving section 70, an increase in the number of steps in the fixing step S02 can be suppressed, and therefore an increase in the number of steps in assembling the imaging unit 630 can be suppressed.

[0113] Seventh Embodiment Figure 18 is a cross-sectional view showing the fixing step S02 of this embodiment. In the following description, the same components as those in the sixth embodiment described above will be assigned the same reference numerals, and their description will be omitted. The imaging unit 730 of this embodiment includes a lens unit 31, an imaging section 740, and a drive section 70. The imaging section 740 of this embodiment includes an imaging element 41, an imaging element fixing section 742, a signal cable 44, an optical element 643, and an imaging element holding member 650.

[0114] The imaging element fixing portion 742 is plate-shaped and extends in a direction perpendicular to the first direction D1. In this embodiment, the imaging element fixing portion 742 has a protruding portion 757. The protruding portion 757 protrudes to the left, i.e., to one side (+D2 side) in the second direction D2. When viewed from the optical axis direction, the protruding portion 757 has a generally triangular shape that protrudes to the left. Although not shown in the figure, the protruding portion 757 is exposed to the outside of the drive unit 70. The protruding portion 757 has a pressing surface 759.

[0115] In this embodiment, the pressing surface 759 is a part of the outer surface of the protrusion 757. The pressing surface 759 is an inclined surface that extends to the left (+D2 side) as it approaches the bottom (+D1 side). The pressing surface 759 faces in a direction that is inclined from the top to the left. Although not shown in the figure, the pressing surface 759 is exposed to the outside of the drive unit 70. Other configurations of the imaging unit 740 of this embodiment are similar to other configurations of the imaging unit 640 of the sixth embodiment described above.

[0116] Next, the fixing step S02 of this embodiment will be described. In the fixing step S02, when an operator applies pressure to the pressing surface 759 using the pressure pin 94, a pressure force F is applied to the pressing surface 759 in a direction tilted from the downward side (+D1 side) to the right side (-D2 side). At this time, a first component force F1 of the pressure force F, which is directed downward, and a second component force F2 of the pressure force F, which is directed rightward, are applied to the imaging element fixing portion 742, thereby fixing the imaging element fixing portion 742 to the fixing jig 691. As a result, the imaging unit 740 is fixed to the fixing jig 691. When the operator applies pressure to the pressing surface 759 to fix the imaging element fixing portion 742 to the fixing jig 691, the fixing step S02 is completed. The other operations of the attachment step S1 of this embodiment are the same as the other operations of the attachment step S1 of the sixth embodiment described above.

[0117] According to this embodiment, the imaging element fixing portion 742 has a protruding portion 757 that protrudes to the left, i.e., to one side (+D2 side) in the second direction D2, and the pressing surface 759 is part of the outer surface of the protruding portion 757. Therefore, as described above, in the fixing step S02, the imaging unit 740 can be fixed to the fixing jig 691 by the simple operation of applying pressure to the pressing surface 759 of the imaging element fixing portion 742 to apply the pressure force F. Therefore, an increase in the number of steps in the fixing step S02 can be suppressed, and therefore an increase in the number of steps for assembling the imaging unit 730 can be suppressed.

[0118] Eighth Embodiment Figure 19 is a cross-sectional view showing the fixing step S02 of this embodiment. In the following description, the same components as those in the sixth embodiment described above will be assigned the same reference numerals, and their description will be omitted. The imaging unit 830 of this embodiment includes a lens unit 31, an imaging section 840, and a drive section 70. The imaging section 840 of this embodiment includes an imaging element 41, an imaging element fixing section 842, a signal cable 44, an optical element 643, and an imaging element holding member 650.

[0119] The imaging element fixing portion 842 is plate-shaped and extends in a direction perpendicular to the first direction D1. In this embodiment, a recess 858 is provided in the imaging element fixing portion 842. The recess 858 is a recess recessed from the left side of the outer surface of the imaging element fixing portion 842, i.e., the surface facing one side in the second direction D2 (the +D2 side), to the right side, i.e., the other side in the second direction D2 (the -D2 side). The recess 858 has a pressing surface 859.

[0120] In this embodiment, the pressing surface 859 is part of the inner surface of the recess 858. The pressing surface 859 is an inclined surface that extends to the left as it approaches the bottom. The pressing surface 859 faces in a direction that is inclined from the top to the left. Although not shown in the figure, the pressing surface 859 is exposed to the outside of the drive unit 70. Other configurations of the imaging unit 840 of this embodiment are similar to other configurations of the imaging unit 640 of the sixth embodiment described above.

[0121] Next, the fixing step S02 of this embodiment will be described. In the fixing step S02, when an operator applies pressure to the pressing surface 859 using the pressure pin 94, a pressure force F is applied to the pressing surface 859 in a direction tilted from the downward side (+D1 side) to the right side (-D2 side). At this time, a first component force F1 of the pressure force F, which is directed downward, and a second component force F2 of the pressure force F, which is directed rightward, are applied to the imaging element fixing portion 842, thereby fixing the imaging element fixing portion 842 to the fixing jig 691. As a result, the imaging unit 840 is fixed to the fixing jig 691. When the operator applies pressure to the pressing surface 859 to fix the imaging element fixing portion 842 to the fixing jig 691, the fixing step S02 is completed. Other operations of the attachment step S1 of this embodiment are similar to those of the attachment step S1 of the sixth embodiment described above.

[0122] According to this embodiment, the imaging element fixing portion 842 is provided with a recess 858 recessed from the left side of the outer surface of the imaging element fixing portion 842, i.e., the surface facing one side (+D2 side) in the second direction D2, to the right side, i.e., the other side (-D2 side) in the second direction D2, and the pressing surface 859 is part of the inner surface of the recess 858. Therefore, as described above, in the fixing step S02, the imaging unit 840 can be fixed to the fixing jig 691 by the simple operation of applying pressure to the pressing surface 859 of the imaging element fixing portion 842 to apply the pressure force F. Therefore, an increase in the number of steps in the fixing step S02 can be suppressed, and therefore an increase in the number of steps for assembling the imaging unit 830 can be suppressed.

[0123] Ninth Embodiment FIG. 20 is a cross-sectional view showing the fixing step S02 of this embodiment. FIG. 21 is a perspective view showing an image sensor holding member 950 of this embodiment. FIG. 22 is a plan view showing the fixing step S02 of this embodiment, viewed from the other side (-D1 side) of the first direction D1. In the following description, components identical to those of the first embodiment described above are designated by the same reference numerals, and their description will be omitted. The imaging unit 930 of this embodiment includes a lens unit 31, an imaging section 940, and a driving section 70. As in the first embodiment described above, the lens unit 31 includes a cylindrical lens barrel 31a that surrounds the optical axis J and extends in the optical axis direction, and multiple lenses 37 held on the inner surface of the lens barrel 31a. As in the first embodiment described above, the driving section 70 moves the movable lens frame 35, i.e., at least one of the multiple lens frames included in the lens barrel 31a, in the optical axis direction. Although not shown, the drive unit 70 covers the upper side of the image sensor holding member 950, i.e., the portion on the other side (+D1 side) in the first direction D1. That is, the drive unit 70 covers a portion of the image sensor holding member 950. As shown in FIG. 20 , the image sensor 940 has the image sensor 41, the image sensor board 42, a signal cable (not shown), and the image sensor holding member 950.

[0124] 21 , the image sensor holding member 950 of this embodiment has a cylindrical portion 51, a first portion 952, and a second portion 953. Although not shown, similarly to the first embodiment described above, the cylindrical portion 51 is fixed to the fixed main body portion 36a of the fixed lens frame 36. This allows the image sensor holding member 950 to be attached to the lens barrel portion 31a. In other words, the image sensor 940 is attached to the lens barrel portion 31a.

[0125] The first portion 952 has a plate shape that extends in a direction perpendicular to the optical axis direction. When viewed from the optical axis direction, the first portion 952 has a generally rectangular shape with its long sides extending in the first direction D1. The first portion 952 is located closer to the base end (-Z side) than the cylindrical portion 51. The first portion 952 is connected to the cylindrical portion 51 in the optical axis direction. As shown in FIG. 20 , the imaging element 41 is fixed to the surface of the first portion 952 facing the base end. This allows the imaging element 41 to be held by the imaging element holding member 950. As shown in FIG. 21 , a through-hole 952a is provided in the first portion 952. The through-hole 952a is a hole that penetrates the first portion 952 in the optical axis direction. When viewed from the optical axis direction, the through-hole 952a has a generally circular shape centered on the optical axis J. As shown in FIG. 20 , the interior of the through-hole 952a is connected to the interior of the cylindrical portion 51. As a result, the optical image of the subject formed by the lens unit 31 passes through the inside of the cylindrical portion 51 and the through-hole 952 a toward the base end side, and is incident on the light receiving surface of the image sensor 41 .

[0126] As shown in FIG. 21 , the second portion 953 is plate-shaped and protrudes from the lower (+D1 side) edge of the first portion 952 toward the base end (−Z side). The plate surface of the second portion 953 faces the first direction D1. As shown in FIG. 20 , the second portion 953 is located below the imaging element 41 and the imaging board 42. The second portion 953 has a first support surface 953b. As shown in FIG. 22 , the second portion 953 has a second support surface 953c and a third support surface 953d. As shown in FIG. 21 , the second portion 953 is provided with a female threaded hole 953a. As shown in FIG. 20 , the first support surface 953b is the surface of the outer surface of the second portion 953 facing downward. As shown in FIG. 22 , the second support surface 953c is the surface of the outer surface of the second portion 953 facing right (−D2 side). The third support surface 953d is a surface of the outer surface of the second portion 953 that faces the left side (+D2 side).

[0127] The female threaded hole 953a is a hole with a female thread formed on its inner circumferential surface. The female threaded hole 953a penetrates the second portion 953 in the first direction D1. When viewed from the first direction D1, the female threaded hole 953a has a substantially circular shape. Although not shown in the figures, the female threaded hole 953a is exposed to the outside of the drive unit 70. Other configurations of the imaging unit 940 of this embodiment are similar to other configurations of the imaging unit 40 of the first embodiment described above.

[0128] Next, the attachment step S1 of this embodiment will be described. In the support step S01, an operator or the like supports each of the first support surface 953b, the second support surface 953c, and the third support surface 953d of the image sensor holding member 950 on a fixing jig 991. Although not shown, in this embodiment, the fixing jig 991 is generally U-shaped when viewed from the optical axis direction. The fixing jig 991 has a first jig portion 991a, a second jig portion 991c, and a third jig portion 991d. As shown in FIG. 20 , the first jig portion 991a is plate-shaped and extends in a direction perpendicular to the first direction D1. Although not shown, when viewed from the first direction D1, the first jig portion 991a has a generally rectangular shape with its long sides extending in the optical axis direction. The first jig portion 991a is disposed below (on the +D1 side of) the second portion 953 and supports the first support surface 953b from below. A hole 991b is provided in the first jig portion 991a. The hole 991b is a hole that penetrates the first jig portion 991a in the first direction D1. When viewed from the first direction D1, the hole 991b overlaps with the female screw hole 953a provided in the second portion 953.

[0129] The second jig portion 991c shown in FIG. 22 is plate-shaped and protrudes upward (toward the -D1 side) from the right-side (-D2 side) end of the first jig portion 991a. The plate surface of the second jig portion 991c faces the second direction D2. The second jig portion 991c is disposed on the right side of the second portion 953 and supports the second support surface 953c from the right side. The third jig portion 991d is plate-shaped and protrudes upward from the left-side (+D2 side) end of the first jig portion 991a. The plate surface of the third jig portion 991d faces the second direction D2. The third jig portion 991d is disposed on the left side of the second portion 953 and supports the third support surface 953d from the left side. As a result, the imaging element holding member 950 is supported by the fixing jig 991. When the worker or the like causes the image pickup element holding member 950 to be supported by the fixing jig 991, the supporting step S01 is completed.

[0130] In the fixing step S02, the worker fixes the image sensor holding member 950 to the fixing jig 991 with a screw 995. As shown in FIG. 20 , the worker passes the screw 995 from the lower side (+D1 side) of the first jig portion 991a through the hole portion 991b and tightens it into the female threaded hole 953a. As a result, a downward fastening force F is applied to the second portion 953, so that the first support surface 953b is pressed against the first jig portion 991a and the image sensor holding member 950 is fixed to the fixing jig 991. At this time, due to the frictional force between the male thread portion of the screw 995 and the female threaded hole 953a, a rotational force F2 is applied to the second portion 953 in a counterclockwise direction about the screw 995 when viewed from the upper side (−D1 side), as shown in FIG. 22 . Therefore, the base end side (-Z side) portion of the second support surface 953c is pressed against the second jig portion 991c, and the object side (+Z side) portion of the third support surface 953d is pressed against the third jig portion 991d. This fixes the image pickup element holding member 950 to the fixing jig 991. In other words, the image pickup unit 940 can be fixed to the fixing jig 991 by the simple task of tightening the screw 995 into the female threaded hole 953a. Once the worker or the like fixes the image pickup element holding member 950 to the fixing jig 991, the fixing step S02 is completed.

[0131] The operations of the adjusting step S03 and the second fixing step S04 of this embodiment are the same as those of the adjusting step S03 and the second fixing step S04 of the first embodiment. When the second fixing step S04 is completed, the mounting step S1 is completed. At this time, the focal position in the optical axis direction of the optical image formed by the lens unit 31 and the light receiving surface of the image sensor 41 are aligned with each other.

[0132] According to this embodiment, the imaging unit 930 includes a lens unit 31 having a cylindrical lens barrel portion 31a extending in the optical axis direction and a lens 37 held on the inner surface of the lens barrel portion 31a, an imaging element holding member 950 attached to the lens barrel portion 31a, and an imaging unit 940 having an imaging element 41 held by the imaging element holding member 950, and the imaging element holding member 950 is provided with a female threaded hole 953a. Therefore, as described above, in the fixing step S02, the imaging element holding member 950 can be fixed to the fixing jig 991 by the simple task of fastening a screw 995 into the female threaded hole 953a. In other words, the imaging unit 940 can be fixed to the fixing jig 991 by the simple task of fastening a screw 995 into the female threaded hole 953a. Therefore, an increase in the number of steps in the fixing step S02 can be suppressed, and therefore an increase in the number of steps for assembling the imaging unit 930 can be suppressed.

[0133] According to this embodiment, the female screw hole 953a is exposed to the outside of the drive unit 70. Therefore, even if the imaging unit 930 includes the drive unit 70, the imaging unit 940 can be fixed to the fixing jig 991 by the simple task of tightening the screw 995 into the female screw hole 953a. Therefore, even if the imaging unit 930 includes the drive unit 70, an increase in the number of steps in the fixing step S02 can be suppressed, and therefore an increase in the number of steps in assembling the imaging unit 930 can be suppressed.

[0134] Although the embodiments of the present invention have been described above, the configurations and combinations thereof in the embodiments are merely examples, and additions, omissions, substitutions, and other modifications of the configurations are possible without departing from the spirit of the present invention. Furthermore, the present invention is not limited to the embodiments.

[0135] The configuration of the imaging unit is not limited to this embodiment, and for example, the second main body frame and the first lens frame may be integrally configured. That is, the second main body frame and the first lens frame may be part of the same single member. Furthermore, the imaging unit does not need to include a drive unit.

[0136] The configuration of the imaging element holding member is not limited to this embodiment, and for example, the holding portion may have other shapes such as a cylindrical shape, a triangular tubular shape, etc. Furthermore, the pressing surface may be a part of the outer surface of the tubular portion.

[0137] 2...endoscope 9...insertion section 30, 230, 330, 430, 530, 630, 730, 830, 930...imaging unit 31...lens unit 31a...lens barrel section 37...lens 40, 240, 340, 440, 540, 640, 740, 840, 940...imaging section 41...imaging element 50, 250, 350, 450, 550, 650, 950...imaging element holding member 52, 252, 352, 452, 552...holding section 53...first wall section 53a...first support surface 54...second wall section 55a...second support surface 57, 357, 457, 557, 757...protruding section 59, 259, 359, 459, 559, 659, 759, 859... Pressing surface 70... Driving unit 91, 491, 691, 991... Fixing jig 258, 358, 858... Recess 357a... Protruding inclined surface 359a... First pressing surface 359c... Second pressing surface 642, 742, 842... Image pickup element fixing portion 643... Optical element 953a... Female screw hole D1... First direction D2... Second direction J... Optical axis S1... Mounting step S01... Supporting step S02... Fixing step S03... Adjusting step

Claims

1. An imaging unit comprising: a lens unit having a cylindrical lens barrel portion extending in the optical axis direction and a lens held on the inner surface of the lens barrel portion; and an imaging unit having an imaging element holding member that is cylindrical and extends in the optical axis direction and attached to the lens barrel portion, and an imaging element held on the inner surface of the imaging element holding member, wherein a direction intersecting the optical axis direction is defined as a first direction and a direction intersecting both the optical axis direction and the first direction is defined as a second direction, a pressing surface is provided on one side of the imaging element holding member in the first direction and one side of the second direction, and the pressing surface extends to one side of the second direction as it approaches one side of the first direction.

2. The imaging unit according to claim 1, further comprising a drive unit that moves a movable lens frame that is included in the lens barrel and that holds the lens in the direction of the optical axis, the drive unit covering the other side of the imaging element holding member in the first direction, and the pressing surface being exposed to the outside of the drive unit.

3. The imaging unit according to claim 1, wherein the imaging element holding member has a cylindrical holding portion extending in the optical axis direction, the imaging element is held on the inner surface of the holding portion, and the pressing surface is provided on the holding portion.

4. The imaging unit according to claim 3, wherein the holding portion has a protruding portion that protrudes to one side in the second direction, and the pressing surface is a part of the outer surface of the protruding portion.

5. An imaging unit as described in claim 3, wherein the holding section is provided with a recess recessed from the surface of the outer surface of the holding section facing one side in the second direction to the other side in the second direction, and the pressing surface is part of the inner surface of the recess.

6. The imaging unit described in claim 3, wherein the holding portion has a protruding portion that protrudes to one side in the second direction, the protruding portion has a protruding inclined surface that extends to one side in the second direction as it approaches the one side in the first direction, and a recess that is recessed from the protruding inclined surface on the opposite side to the direction in which the protruding inclined surface faces, the imaging element holding member is provided with a plurality of pressing surfaces, the plurality of pressing surfaces including a first pressing surface and a second pressing surface, each of the first pressing surface and the second pressing surface being an inner surface of the recess and facing each other in the optical axis direction, and the distance in the optical axis direction between the first pressing surface and the second pressing surface becoming smaller as it approaches the other side in the second direction.

7. The imaging unit described in claim 3, wherein the holding portion has a first wall portion and a second wall portion extending in the second direction and formed along the horizontal pixel direction of the imaging element, the first wall portion being located on one side of the second wall portion in the first direction, and the thickness of the first wall portion being thicker than the thickness of the second wall portion.

8. The imaging unit according to claim 1, wherein the imaging element holding member has a cylindrical holding portion extending in the optical axis direction and a protruding portion protruding from the holding portion toward the base end, the imaging element is held on the inner surface of the holding portion, and the pressing surface is part of the outer surface of the protruding portion.

9. The imaging unit according to claim 8, wherein the pressing surface extends toward one side in the first direction as it approaches the base end side.

10. An imaging unit comprising: a lens unit having a cylindrical lens barrel portion extending in the optical axis direction and a lens held on the inner surface of the lens barrel portion; and an imaging portion having an imaging element and an imaging element fixing portion to which the imaging element is fixed, wherein a direction intersecting the optical axis direction is defined as a first direction, and a direction intersecting both the optical axis direction and the first direction is defined as a second direction, and the imaging element fixing portion is provided with a pressing surface that extends to one side of the second direction as it moves toward one side of the first direction.

11. An imaging unit as described in claim 10, comprising a drive unit that moves a movable lens frame that is included in the lens barrel and that holds the lens in the optical axis direction, the imaging unit having a cylindrical imaging element holding member that extends in the optical axis direction, the imaging element holding member holding the imaging element fixing portion, the drive unit covering the other side portion of the imaging element holding member in the first direction, and the pressing surface being exposed to the outside of the drive unit.

12. The imaging unit according to claim 10, wherein the imaging element fixing portion has a protruding portion that protrudes to one side in the second direction, and the pressing surface is a part of the outer surface of the protruding portion.

13. The imaging unit described in claim 10, wherein the imaging element fixing portion has a recess recessed from the surface of the outer surface of the imaging element fixing portion facing one side in the second direction to the other side in the second direction, and the pressing surface is part of the inner surface of the recess.

14. An endoscope having the imaging unit according to claim 1 at the tip of an insertion section.

15. A method for assembling an imaging unit comprising: a lens unit having a cylindrical lens barrel portion extending in the optical axis direction and a lens held on the inner surface of the lens barrel portion; an imaging unit having an imaging element holding member that is cylindrical and extends in the optical axis direction and attached to the lens barrel portion, and an imaging unit having an imaging element held on the inner surface of the imaging element holding member, the method for assembling the imaging unit comprising an attachment step of attaching the imaging unit to the lens unit, wherein a direction intersecting the optical axis direction is defined as a first direction, and a direction intersecting both the optical axis direction and the first direction is defined as a second direction, a pressing surface is provided on one side of the first direction and one side of the second direction of the imaging element holding member, the pressing surface extending towards one side of the second direction as it approaches one side of the first direction, and the attachment step comprises: a supporting step of supporting, on a fixing jig, a first supporting surface, which is an outer surface of the image sensor holding member facing one side in the first direction, and a second supporting surface, which is an outer surface of the image sensor holding member facing the other side in the second direction; a fixing step of applying pressure to the pressing surface to fix the image sensor holding member to the fixing jig; and an adjusting step of adjusting a position in the optical axis direction of at least one of a plurality of lens frames included in the barrel portion.

Images