Lens unit and imaging device

Abstract

To provide a lens unit that is easy to assemble while suppressing an increase in radial size.SOLUTION: A lens unit includes a holding member 5 that holds a lens 6d on an inner circumferential side, and a pressing member 15 that is disposed on an inner circumference of the holding member, contacts a contact surface 5e of the holding member from an optical axis direction, is fixed to the holding member by a fixing member AD, and thereby presses the lens against the holding member from the optical axis direction. The holding member has a first concave portion 5d that is concave toward an outside in a radial direction at at least one location in a circumferential direction. The pressing member has a second concave portion 15c that is concave toward an inside in the radial direction at at least one location in the circumferential direction. The fixing member is disposed in an area facing the first concave portion, the second concave portion, and the contact surface.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an imaging device such as an in-vehicle camera or a surveillance camera. [Background technology]

[0002] As described above, image capture devices that are often used in outdoor environments are required to have impact resistance against external forces.

[0003] Patent Document 1 discloses a lens module including a first lens provided on the object side and a fixing member that holds the first lens by pressing it against the front end of the lens barrel from the object side. The lens barrel is adhesively fixed to the fixing member. Patent Document 2 discloses a lens module including a lens provided on the object side and a fixing member that fixes the lens by pressing it against the front end of the lens barrel from the object side. An adhesive is filled between the lens and an abutment portion of the fixing member that abuts against the lens. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2020-27284 A [Patent Document 2] JP 2020-27278 A Summary of the Invention [Problem to be solved by the invention]

[0005] Adhesive treatment of the lens to the fixed member is effective for improving impact resistance. However, the configuration of Patent Document 1 is premised on the configuration in which the fixed member is fixed to the outer periphery of the lens barrel, and the lens module becomes larger in diameter by the radial size of the fixed member. In addition, in the configuration of Patent Document 2, adhesive is applied between the fixed member and the lens, so assembly is required to prevent the adhesive from spreading into the optically effective area of ​​the lens, which is not easy to assemble.

[0006] The present invention provides a lens unit that is easy to assemble while suppressing an increase in radial size, and an imaging device including the same. [Means for solving the problem]

[0007] The lens unit according to one aspect of the present invention includes a holding member that holds the lens on its inner periphery, and a pressing member that is disposed on the inner periphery of the holding member and abuts against an abutment surface of the holding member in the optical axis direction and is fixed to the holding member by a fixing member, thereby pressing the lens against the holding member in the optical axis direction. The holding member has a first recess that is recessed radially outward at at least one location in the circumferential direction. The pressing member has a second recess that is recessed radially inward at at least one location in the circumferential direction. The fixing member is disposed in an area facing the abutment surface of the first recess and the second recess. Note that an imaging device having the lens unit and an imaging element that images a subject through the lens also constitutes another aspect of the present invention. Effect of the Invention

[0008] According to the present invention, it is possible to provide a lens unit that is easy to assemble while suppressing an increase in radial size, and an imaging device including the same. [Brief description of the drawings]

[0009] [Figure 1] 3A and 3B are a rear view and a cross-sectional view of the lens unit of the first embodiment. [Diagram 2] FIG. 2 is a cross-sectional view of the imaging unit according to the first embodiment. [Diagram 3] FIG. 2 is an exploded perspective view of the imaging unit according to the first embodiment, as viewed from the object side. [Figure 4] FIG. 2 is an exploded perspective view of the imaging unit according to the first embodiment as viewed from the image side. [Diagram 5] FIG. 1 is a perspective view of a camera according to a first embodiment. [Figure 6] 11A and 11B are a rear view and a cross-sectional view of a lens unit according to a second embodiment. [Figure 7] FIG. 11 is a cross-sectional view of an imaging unit according to a second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, embodiments of the present invention will be described with reference to the drawings. EXAMPLES

[0011] The imaging device of the first embodiment is particularly suitable for use in outdoor environments such as vehicle-mounted cameras and surveillance cameras, etc. However, imaging devices according to the embodiments of the present invention also include those for use indoors.

[0012] 5 shows the appearance of a camera 100 of this embodiment. The camera 100 has an imaging unit 1 as an imaging device and an exterior member 2 that holds the imaging unit 1. The imaging surface side of the imaging unit 1 is housed in the exterior member 2 and fixed to the exterior member 2 with screws (not shown), and the object side of the imaging unit 1 is exposed from an opening provided in the front surface of the exterior member 2. The gap between the opening of the exterior member 2 and the outer periphery of the imaging unit 1 is sealed with a seal member (not shown) to prevent water and dust from entering through the gap.

[0013] A cover 3 is fixed to the rear surface of the exterior member 2 with screws (not shown). A sealing member (not shown) is sandwiched between the exterior member 2 and the cover 3, which prevents water and dust from entering through a gap between the exterior member 2 and the cover 3. An external interface (not shown) is also provided on the cover 3. By connecting a cable to this external interface, a video signal generated by imaging by the imaging unit 1 can be output to the outside. The external interface may have a wireless communication function for the video signal.

[0014] Fig. 2 shows the internal structure of the imaging unit 1. Fig. 3 shows an exploded view of the imaging unit 1 as viewed from the object side (subject side). Fig. 4 shows an exploded view of the imaging unit 1 as viewed from the image plane side (hereinafter referred to as the sensor side). The dashed dotted line shown in Fig. 2 indicates the optical axis, and in the following description, the direction in which the optical axis extends is referred to as the optical axis direction, the direction perpendicular to the optical axis is referred to as the radial direction, and the direction around the optical axis is referred to as the circumferential direction.

[0015] The housing 4 has an opening 4a on the object side, an opening 4b on the sensor side, and an inner peripheral thread portion 4c provided on the inner circumference, and holds the lens unit 30 on its inner circumference side. The lens unit 30 is composed of a lens frame 5 and lenses 6a, 6b, 6c, and 6d. The lens unit 30 is inserted into the opening 4a, and is held by the housing 4 by screwing the outer peripheral thread portion 5a provided on the outer periphery of the lens frame 5 into the inner peripheral thread portion 4c provided on the inner circumference of the housing 4.

[0016] From the viewpoint of weather resistance in outdoor use, it is desirable that the housing 4 and the lens frame 5 are made of metal. A circumferential groove 5b is formed in the portion of the outer periphery of the lens frame 5 closer to the object side than the outer periphery thread portion 5a, and an elastic body (second seal member) 7 such as an O-ring is fitted into the circumferential groove 5b. The elastic body 7 seals the gap between the outer periphery of the lens frame 5 and the inner periphery of the housing 4, preventing the intrusion of water and dust from the gap between them.

[0017] The sensor unit 8 has an imaging element 8a such as a CMOS sensor. The sensor unit 8 is placed inside the opening 4b of the housing 4, and is fixed to a receiving portion provided in the opening 4b with a screw 9. In this way, the sensor unit 8 is held by the housing 4 together with the lens unit 30. Since the outer peripheral thread portion 5a of the lens unit 30 is screwed into the inner peripheral thread portion 4c of the housing 4 as described above, the position of the lens unit 30 in the optical axis direction relative to the sensor unit 8 can be adjusted by rotating the lens unit 30 about the optical axis relative to the housing 4.

[0018] In the lens unit 30, the lens frame 5 as a holding member holds the lenses 6a to 6d on its inner circumference side. An opening is formed at each of the object side end and the sensor side end of the lens frame 5. The lens 6b, the spacer 11, the elastic body 10 such as an O-ring, and the lens 6a are inserted into the inner circumference of the lens frame 5 in this order from the object side opening. The front pressing ring 12 is fixed to the lens frame 5 while abutting against the lens 6a closest to the object side by screwing an outer peripheral threaded portion (not shown) provided on the outer periphery of the front pressing ring 12 into an inner peripheral threaded portion (not shown) provided on the inner periphery of the lens frame 5. As a result, the elastic body 10 is sandwiched between the lens 6a and the lens frame 5, the gap between the lens 6a and the lens frame 5 is sealed, and the intrusion of water and dust from the gap is prevented.

[0019] Furthermore, the lens 6c is inserted into the inner circumference of the lens frame 5 from the opening on the sensor side, and is fixed to the lens frame 5 by an adhesive as a fixing member. Furthermore, the lens 6d, a fixing plate 13, and an elastic body (elastic member) 14 such as an O-ring are inserted in this order into the inner circumference of the lens frame 5 from the opening on the sensor side. The rear pressing ring 15 as a pressing member is fixed to the lens frame 5 while abutting against the elastic body 14 by having an outer peripheral screw 15a provided on the outer circumference screw portion 15a screwed into an inner peripheral screw portion 5c provided on the inner circumference of the lens frame 5.

[0020] The rear retaining ring 15 is screwed into the lens frame 5 until its contact surface 15b contacts the contact surface 5e of the lens frame 5. As a result, the elastic body 14 is sandwiched between the rear retaining ring 15 and the fixed plate 13, and the rear retaining ring 15 is held by the lens frame 5 in a state in which the lens 6d closest to the sensor is biased toward the object side by the elastic force of the elastic body 14. In this configuration, the lens 6d is pressed against the lens frame 5 with a force lower than when the rear retaining ring 15 directly presses the lens 6d toward the object side against the lens frame 5. This suppresses deformation of the lens surface of the lens 6d, and prevents deterioration of optical performance. However, if deformation of the lens surface of the lens 6d can be suppressed, the rear retaining ring 15 may be directly pressed against the lens 6d to hold the lens 6d by the lens frame 5.

[0021] Fig. 1(A) shows the lens unit 30 as seen from the sensor side, and Fig. 1(B) shows a cross section taken along line AA in Fig. 1(A). Also, Fig. 1(C) shows an enlarged view of region B in Fig. 1(B).

[0022] A notch 5d is formed as a first recess recessed toward the outside in the radial direction at one location in the circumferential direction of the inner peripheral threaded portion 5c of the lens frame 5. The peripheral surface within the notch 5d is an arc surface (part of a cylindrical surface) extending in the optical axis direction. Meanwhile, a notch 15c is formed as a second recess recessed toward the inside in the radial direction at one location in the circumferential direction of the outer peripheral threaded portion 15a of the rear presser ring 15. The object side portion of the peripheral surface within the notch 15c is an arc surface extending in the optical axis direction, and the sensor side portion is an inclined surface (frustum surface) inclined toward the optical axis toward the sensor side with respect to the optical axis direction so as to approach the optical axis.

[0023] When the rear pressing ring 15 is screwed into the lens frame 5, the notch 15c and the notch 5d face each other in the radial direction, i.e., are positioned so as to be in the same phase in the circumferential direction. In addition, the abutment surface 5e is exposed toward the sensor side between the notch 15c and the notch 5d. As a result, a space (area) V1 is formed that faces the notch 15c, the notch 5d, and the abutment surface 5e and opens toward the sensor side. An adhesive AD is placed in this space V1. As a result, the rear pressing ring 15 (the notch 15c) is adhesively fixed to the lens frame 5 (the notch 5d and the abutment surface 5e).

[0024] Furthermore, by providing a slope in the cutout 15c, the radial width of the opening on the sensor side of the space V1 is increased, improving the workability when filling the area V1 with adhesive. Note that at least one of the cutout 15c and the cutout 5d may be formed so that the radial width of the space V1 is increased toward the sensor side (the side opposite to the contact surface 5e in the optical axis direction).

[0025] In this embodiment, the fixing is performed by using an adhesive. However, the fixing may be performed by filling an elastic material such as a sealant without using an adhesive.

[0026] In addition, the length of the cutout in the circumferential direction may be such that either the cutout 5d or the cutout 15c is longer than the other. This ensures that the cutout 15c and the cutout 5d face each other in the circumferential direction to form the space V1 even if the phase of the cutout 5d and the cutout 15c is slightly shifted due to manufacturing variations in parts, and good adhesive strength is obtained. Also, the cutouts 15c and 5d may be provided at multiple locations in the circumferential direction of the rear press ring 15 and the lens frame 5, respectively.

[0027] In this manner, in this embodiment, the diameter of the lens unit 30 can be reduced by screwing the rear press ring 15 into the lens frame 5, while an adhesive reservoir (space V1) for adhesively fixing the rear press ring 15 to the lens frame 5 can be formed. This allows the rear press ring 15 to be adhered to the lens frame 5 without the adhesive AD for adhering the rear press ring 15 flowing around onto the lens surface of the lens 6d. In other words, it is possible to provide a lens unit that has good assembly properties (adhering workability) while suppressing an increase in the radial size of the lens unit 30.

[0028] In this embodiment, the holding structure of the rear pressing ring 15 that holds the lens 6d closest to the sensor has been described, but a similar holding structure may be applied to the front pressing ring 12 that holds the lens 6a closest to the object. EXAMPLES

[0029] Next, a second embodiment will be described. Fig. 7 shows the internal structure of an imaging unit 1000 in the second embodiment. In this embodiment, components common to the first embodiment are given the same reference numerals as in the first embodiment, and a description thereof will be omitted. In this embodiment, a lens unit 300 having a different configuration from the lens unit 30 in the first embodiment will be mainly described.

[0030] The lens unit 300 is composed of a lens frame 50 serving as a first holding member to which the lenses 6a to 6d are directly fixed and held, and an outer frame 16 serving as a second holding member that holds the inner periphery of the lens frame 50. Openings are provided at the object side end and the sensor side end of each of the lens frame 50 and the outer frame 16.

[0031] It is desirable that the lens frame 50 is made of resin, and the outer frame 16 is made of metal. By making the lens frame 50 a resin part, it is possible to press-fit and hold the lenses 6a to 6d into the inner circumference of the lens frame 50. This makes it possible to hold the lenses with higher positional accuracy than in Example 1, in which the lens frame 5 is a metal part. Furthermore, by holding the lens frame 50 with the metal outer frame 16, it is possible to prevent the lens frame 50 from being directly exposed to the outdoor environment, such as sunlight, and improve the weather resistance of the lens unit 300.

[0032] The lens unit 300 is inserted into the opening 4a of the housing 4, and is held by the housing 4 as the outer peripheral threaded portion 16e provided on the outer periphery of the outer frame 16 screws into the inner peripheral threaded portion 4c of the housing 4.

[0033] The lens frame 50 holds the lenses 6a to 6d on its inner periphery. The lenses 6b, 6a are inserted into the inner periphery of the lens frame 50 in this order from the opening on the object side. The lenses 6a, 6b are fixed and held in the lens frame 50 by thermal caulking. An elastic body (first seal member) 70 such as an O-ring is disposed within a stepped portion provided on the object side of the outer periphery of the lens 6a.

[0034] Furthermore, the lens 6c is inserted into the inner circumference of the lens frame 50 from the opening on the sensor side. The lens 6c is fixed and held in the lens frame 50 by thermal caulking. An outer peripheral threaded portion 50a is formed on the outer circumference of the lens frame 50. The lens frame 50 is held by the outer frame 16 by screwing the outer peripheral threaded portion 50a into an inner peripheral threaded portion 16a received in the inner circumference of the outer frame 16.

[0035] At this time, the elastic body 70 is sandwiched between the flange portion 16b as a protrusion formed so as to protrude radially inward at the front end of the outer frame 16 (toward the object side of the lens 6a closest to the object) and the lens 6a held by the lens frame 50. This seals the gap between the flange portion 16b and the lens 6a, preventing the intrusion of water and dust from the gap.

[0036] Furthermore, the lens 6d, the fixed plate 13, the elastic body 14, and the rear pressing ring 15 as a pressing member are inserted in this order from the opening on the sensor side into the inner circumference of the outer frame 16 holding the lens frame 50. The rear pressing ring 15 is held by the outer frame 16 while abutting against the elastic body 14 by having an outer peripheral screw 15a provided on the outer circumference screwed into an inner peripheral screw portion 16c provided on the inner circumference of the outer frame 16.

[0037] The rear retaining ring 15 is screwed into the outer frame 16 until its contact surface 15b contacts the contact surface 50e of the lens frame 50. As a result, similar to the first embodiment, the elastic body 14 is sandwiched between the rear retaining ring 15 and the fixed plate 13, and the rear retaining ring 15 is held by the outer frame 16 in a state in which the lens 6d closest to the sensor is biased toward the object side by the elastic force of the elastic body 14. In this configuration, the lens 6d is pressed against the lens frame 50 with a force lower than that when the rear retaining ring 15 directly presses the lens 6d against the lens frame 50 toward the object side. This suppresses deformation of the lens surface of the lens 6d, and prevents deterioration of optical performance. However, if deformation of the lens surface of the lens 6d is suppressed, the rear retaining ring 15 may be directly pressed against the lens 6d to hold the lens 6d by the lens frame 50.

[0038] Fig. 6(A) shows the lens unit 300 as seen from the sensor side, and Fig. 6(B) shows a cross section taken along line CC in Fig. 6(A). Also, Fig. 6(C) shows an enlarged view of region D in Fig. 6(B).

[0039] A notch 16d is formed as a first recess recessed toward the radially outward direction at one circumferential location of the inner peripheral threaded portion 16c of the outer frame 16. The peripheral surface within the notch 16d is an arc surface (part of a cylindrical surface) extending in the optical axis direction. As in the first embodiment, a notch 15c is formed as a second recess recessed toward the radially inward direction at one circumferential location of the outer peripheral threaded portion 15a of the rear press ring 15. The object side portion of the peripheral surface within the notch 15c is an arc surface extending in the optical axis direction, and the sensor side portion is an inclined surface.

[0040] When the rear press ring 15 is screwed into the outer frame 16, the notch 15c and the notch 16d are positioned so as to face each other in the radial direction (in the same phase in the circumferential direction). In addition, the contact surface 50e of the lens frame 50 is exposed toward the sensor side between the notch 15c and the notch 16d. As a result, a space (area) V2 is formed that faces the notch 15c, the notch 16d, and the contact surface 50e and opens toward the sensor side. An adhesive AD is placed in this space V2. As a result, the rear press ring 15 (notch 15c) is adhesively fixed to the outer frame 16 (notch 16d) and the lens frame 50 (contact surface 50e).

[0041] In this embodiment, too, by providing a slope in the cutout 15c, the radial width of the opening on the sensor side of the space V2 is increased, and the workability when filling the adhesive in the region V2 can be improved. Note that it is sufficient that at least one of the cutout 15c and the cutout 16d is formed so that the radial width of the space V2 is increased toward the sensor side (the side opposite to the contact surface 50e in the optical axis direction).

[0042] In addition, the length of the notch in the circumferential direction may be longer for either the notch 16d or the notch 15c than the other. As a result, even if the phase of the notch 16d and the notch 15c is slightly shifted due to manufacturing variations in parts, the circumferential length of the notch 16d and the notch 15c facing each other for forming the space V2 can be sufficiently secured, and good adhesive strength can be obtained. Also, the notches 15c and 16d may be provided at multiple locations in the circumferential direction of the rear press ring 15 and the outer frame 16, respectively. In this embodiment, the rear press ring 15 is screwed into the outer frame 16 to reduce the diameter of the lens unit 300, while forming an adhesive reservoir (space V2) for bonding the rear press ring 15 to the outer frame 16 and the lens frame 50. As a result, the rear press ring 15 can be bonded to the outer frame 16 and the lens frame 50 without the adhesive for bonding the rear press ring 15 getting around the lens surface of the lens 6d. That is, it is possible to provide a lens unit that has good assembly properties (bonding workability) while suppressing an increase in the radial size of the lens unit 300.

[0043] In the first and second embodiments, the holding structure in which the rear presser ring 15 is screwed to the lens frame 5 or the outer frame 16 has been described, but other holding structures such as a bayonet connection may also be used.

[0044] The above embodiment includes the following configurations. (Configuration 1) a holding member that holds the lens on an inner circumferential side; a pressing member that is disposed on an inner periphery of the holding member, abuts against a contact surface of the holding member in the optical axis direction and is fixed to the holding member by a fixing member, thereby pressing the lens against the holding member in the optical axis direction; The retaining member has a first recess recessed radially outward at at least one location in a circumferential direction, The pressing member has a second recess recessed radially inward at at least one location in the circumferential direction, The lens unit is characterized in that the fixing member is disposed in an area facing the first recess, the second recess, and the contact surface. (Configuration 2) 2. The lens unit according to configuration 1, wherein the fixing member is an adhesive. (Configuration 3) The retaining member has an internally threaded portion, The pressing member has an outer peripheral threaded portion, The lens unit described in configuration 2, wherein the pressing member is assembled to the holding member by screwing the outer peripheral threaded portion into the inner peripheral threaded portion until it abuts against the abutment surface, and is fixed to the first holding member by the adhesive. (Configuration 4) the holding member is composed of a first holding member to which the lens is fixed and a second holding member that holds the first holding member on an inner peripheral side, the pressing member is fixed to the first and second holding members by the adhesive while being in contact with the contact surface of the first holding member; 3. The lens unit according to configuration 2, wherein the first recess is provided in the second holding member. (Configuration 5) the second retaining member has an internally threaded portion, The pressing member has an outer peripheral threaded portion, The lens unit described in configuration 4, wherein the pressing member is assembled to the second holding member by screwing the outer peripheral threaded portion into the inner peripheral threaded portion until it abuts against the abutment surface, and is fixed to the first and second holding members by the adhesive. (Configuration 6) the second holding member has a protruding portion that protrudes radially inward on the object side relative to a lens closest to the object side that is the lens held by the first holding member, The lens unit according to configuration 4 or 5, wherein a first seal member is disposed between the protruding portion and the lens closest to the object side. (Configuration 7) The first recess is provided at least at one location in the circumferential direction of the internally threaded portion, The lens unit according to configuration 3 or 5, wherein the second recess is provided at least at one location in the circumferential direction of the outer peripheral threaded portion. (Configuration 8) The lens unit described in any one of configurations 1 to 7, characterized in that at least one of the first and second recesses is formed so that the radial width of the region becomes wider toward the opposite side to the abutment surface in the optical axis direction. (Configuration 9) The lens unit according to any one of configurations 1 to 8, wherein the circumferential length of at least one of the first and second recesses is longer than the circumferential length of the other of the first and second recesses. (Configuration 10) an elastic member is disposed between the pressing member and the lens; 10. The lens unit according to any one of configurations 1 to 9, wherein the pressing member presses the lens against the holding member via the elastic member. (Configuration 11) A lens unit according to any one of configurations 1 to 10; and an image sensor for capturing an image of a subject through the lens. (Configuration 12) a housing that holds the lens unit and the image sensor on an inner periphery side, 12. The imaging device according to configuration 11, wherein the lens unit is held by the housing so as to be positionally adjustable in the optical axis direction relative to the imaging element. (Configuration 13) 13. The imaging device according to configuration 12, wherein a second seal member is disposed between an inner periphery of the housing and an outer periphery of the holding member.

[0045] The embodiments described above are merely representative examples, and various modifications and alterations are possible for each embodiment when implementing the present invention. [Explanation of symbols]

[0046] 30,300 Lens unit 5,50 Lens frame 5d Cutout 6a~6d Lenses 8 Sensor Unit 14. Chassis 15 Rear presser ring 15c Cutout 16 Outer Frame 16d Cutout

Claims

1. a holding member that holds the lens on an inner circumferential side; a pressing member that is disposed on an inner periphery of the holding member, abuts against a contact surface of the holding member in the optical axis direction and is fixed to the holding member by a fixing member, thereby pressing the lens against the holding member in the optical axis direction; The retaining member has a first recess that is recessed radially outward at at least one location in a circumferential direction, The pressing member has a second recessed portion recessed radially inward at at least one location in a circumferential direction, A lens unit, characterized in that the fixing member is disposed in an area facing the first recess, the second recess, and the contact surface.

2. 2. The lens unit according to claim 1, wherein the fixing member is an adhesive.

3. The retaining member has an internally threaded portion, The pressing member has an outer peripheral threaded portion, The lens unit according to claim 2, characterized in that the pressing member is assembled to the holding member by screwing the outer peripheral threaded portion into the inner peripheral threaded portion until it abuts against the abutment surface, and is fixed to the first holding member by the adhesive.

4. the holding member is composed of a first holding member to which the lens is fixed and a second holding member that holds the first holding member on an inner peripheral side thereof, the pressing member is fixed to the first and second holding members by the adhesive while being in contact with the contact surface of the first holding member; The lens unit according to claim 2 , wherein the first recess is provided in the second holding member.

5. the second retaining member has an internally threaded portion, The pressing member has an outer peripheral threaded portion, The lens unit according to claim 4, characterized in that the pressing member is assembled to the second holding member by screwing the outer peripheral threaded portion into the inner peripheral threaded portion until it abuts against the abutment surface, and is fixed to the first and second holding members by the adhesive.

6. the second holding member has a protruding portion that protrudes radially inward on the object side relative to a lens closest to the object side that is the lens held by the first holding member, 5. The lens unit according to claim 4, further comprising a first seal member disposed between the protruding portion and the lens closest to the object side.

7. The first recess is provided at least at one location in a circumferential direction of the internally threaded portion, 6. The lens unit according to claim 3, wherein the second recess is provided at least at one location in the circumferential direction of the outer peripheral threaded portion.

8. The lens unit according to claim 1 , characterized in that at least one of the first and second recesses is formed such that the radial width of the region becomes wider toward the opposite side to the abutment surface in the optical axis direction.

9. 2. The lens unit according to claim 1, wherein the length in the circumferential direction of at least one of the first and second recesses is longer than the length in the circumferential direction of the other of the first and second recesses.

10. an elastic member is disposed between the pressing member and the lens; 2. The lens unit according to claim 1, wherein the pressing member presses the lens against the holding member via the elastic member.

11. The lens unit according to claim 1 ; and an image sensor for capturing an image of a subject through the lens.

12. a housing that holds the lens unit and the image sensor on an inner periphery side, 12. The imaging apparatus according to claim 11, wherein the lens unit is held by the housing so as to be positionally adjustable in the optical axis direction relative to the imaging element.

13. 13. The image pickup apparatus according to claim 12, further comprising a second seal member disposed between an inner periphery of the housing and an outer periphery of the holding member.

Images