Lens unit and imaging device

Abstract

To provide a lens unit in which the surface distortion of a lens can be reduced, the surface distortion occurring during fixing of the lens to a lens holding frame.SOLUTION: A lens unit (100) includes a lens (102) and a lens holding frame (101), the lens has a first outer diameter portion (109) and a second outer diameter portion (110), the lens holding frame has a first cylindrical portion (104), a second cylindrical portion (107), a flange portion (108) and an abutment portion (106), a press-in portion (105) is provided in the first cylindrical portion. The gravity center (x1) in an optical axis direction, of the lens is positioned within the range of a contact region (A) of the press-in portion with the first outer diameter portion, a difference y1 between the first outer diameter portion and the second outer diameter portion and a difference B between the radius of the first outer diameter portion and the radius of tip of the abutment portion (103) for pressing the lens from the side which is reverse to the abutment portion satisfy the conditional expression 0<y1<B.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a lens unit and an imaging device. [Background technology]

[0002] In recent years, in order to improve the optical performance of lens units used in imaging devices such as single-lens reflex cameras, it is desirable to suppress the decrease in surface accuracy (surface distortion) when a lens is fixed to a lens holding frame. Common methods for fixing a lens to a lens holding frame include a ring member (presser ring) that is screwed into the lens holding frame and comes into contact with the lens, caulking that fixes the lens by deforming the lens holding frame using heat or pressure, and fixing methods using adhesives.

[0003] However, in the case of fixing by crimping or bonding, the direction perpendicular to the optical axis of the lens is often restricted by the press-fitting of a resin lens holding frame, which causes distortion of the lens. In addition, the action of the screw when tightening the press ring and the pressure during crimping often cause distortion of the lens holding frame and the lens. Therefore, Patent Document 1 discloses a configuration for limiting the contact portion of the lens holding frame that contacts the outer periphery of the lens. Patent Document 2 discloses a configuration for suppressing the instability of accuracy due to the influence of distortion of the roundness of the lens holding frame by softening the lens holding frame. Patent Document 3 discloses a configuration for providing notches at the front and rear of the lens press-fitting portion in the optical axis direction, and making the strength of the lens holding frame uniform at the front and rear of the optical axis direction. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 3002529 [Patent Document 2] JP 2006-64857 A [Patent Document 3] JP 2019-179075 A Summary of the Invention

Problems to be Solved by the Invention

[0005] However, with the configurations disclosed in Patent Documents 1 to 3, it is not possible to sufficiently suppress the surface distortion of the lens.

[0006] Therefore, an object of the present invention is to provide a lens unit and an imaging device capable of reducing the surface distortion of a lens that occurs when the lens is fixed to a lens holding frame.

Means for Solving the Problems

[0007] A lens unit according to one aspect of the present invention includes a lens and a lens holding frame that holds the lens. The lens has a first outer diameter portion and a second outer diameter portion. The lens holding frame includes a first cylindrical portion that houses the lens, a second cylindrical portion located on the outer diameter side of the first cylindrical portion, a flange portion provided between the first cylindrical portion and the second cylindrical portion, and a contact portion that contacts the lens in the optical axis direction. a contact portion for pressing the lens from the side opposite to the contact portion; The first cylindrical portion is provided with a press-fitting portion into which the first outer diameter portion is press-fitted. The first outer diameter portion has a larger diameter than the second outer diameter portion. The second outer diameter portion is located closer to the contact portion than the first outer diameter portion. In the optical axis direction, the center of gravity of the lens is located within the range of the contact region between the press-fitting portion and the first outer diameter portion. The difference y1 between the radius of the first outer diameter portion and the radius of the second outer diameter portion, and the difference B between the radius of the first outer diameter portion and the radius of the tip of the contact portion of the lens with the notes satisfy the conditional expression 0 < y1 < B.

[0008] Other objects and features of the present invention will be described in the following embodiments.

Advantages of the Invention

[0009] According to the present invention, it is possible to provide a lens unit and an imaging device capable of reducing the surface distortion of a lens that occurs when the lens is fixed to a lens holding frame.

Brief Description of the Drawings

[0010] [Figure 1] FIG. 2 is an enlarged view of a main portion of the lens unit according to the first embodiment. [Diagram 2] FIG. 2 is a cross-sectional view of a lens unit according to the first embodiment. [Diagram 3] FIG. 2 is an exploded perspective view of the lens unit according to the first embodiment. [Figure 4] 11 is an explanatory diagram of surface distortion caused by press-fitting when the position of the contact area A is changed. FIG. [Diagram 5] 11A and 11B are explanatory diagrams of surface distortion caused by press-fitting when the wall thickness of the inner diameter side cylindrical portion of the lens holding frame is changed. [Figure 6] 13 is an explanatory diagram of surface distortion caused by press-fitting when the optical axis direction range C of the flange portion is shifted. FIG. [Figure 7] 1 is a diagram showing the relationship between the distance from the optical axis of a lens to a position that regulates the optical axis direction and surface distortion. [Figure 8] FIG. 11 is a cross-sectional view of a lens unit according to a second embodiment. [Figure 9] FIG. 11 is an enlarged view of a main portion of a lens unit according to a second embodiment. [Figure 10] FIG. 2 is a schematic diagram of an imaging device in each embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

[0012] <First embodiment> First, a lens unit 100 according to a first embodiment of the present invention will be described with reference to Figures 2 and 3. Lens unit 100 constitutes a part of a so-called lens device such as an interchangeable lens camera or a compact digital camera, and the lens device is attached to a camera body when used.

[0013] Fig. 2 is a cross-sectional view taken along a plane parallel to the optical axis O of the lens unit 100 in this embodiment. Fig. 3 is an exploded perspective view of the lens unit 100. The lens unit 100 has a lens 102 and a lens holding frame (lens holding portion) 101 that holds the lens 102.

[0014] The lens 102 is made of a resin material or a glass material. The lens holding frame 101 is made of a resin material and fixes the lens 102 by a configuration described later. The lens holding frame 101 has an inner diameter side cylindrical portion (first cylindrical portion) 104, a lens press-fit portion (press-fit portion) 105, a lens body attachment portion (abutment portion) 106, an outer diameter side cylindrical portion (second cylindrical portion) 107, and a flange portion 108 on the outer diameter portion of the lens 102. The inner diameter side cylindrical portion 104 houses the lens 102. The lens press-fit portion 105 is provided in a part of the inner diameter side cylindrical portion 104, and for example, three lens press-fit portions 105 are arranged apart from each other, and regulate the position of the lens 102 in a direction perpendicular to the optical axis O (position perpendicular to the optical axis, position in the radial direction). The lens 102 is fixed to the lens holding frame 101 in the radial direction by press-fitting due to elastic deformation.

[0015] The lens barrel portion 106 abuts against the lens 102 in a direction along the optical axis O of the lens 102 (optical axis direction) and regulates the position of the lens 102 in the optical axis direction. The outer diameter side cylindrical portion 107 is located on the outer diameter side of the inner diameter side cylindrical portion 104. The flange portion 108 is provided between the inner diameter side cylindrical portion 104 and the outer diameter side cylindrical portion 107 and connects the inner diameter side cylindrical portion 104 and the outer diameter side cylindrical portion 107. In this embodiment, the flange portion 108 is a substantially circumferential portion extending from the inner diameter side cylindrical portion 104 toward the outer diameter side cylindrical portion 107. In this embodiment, the lens holding frame 101 has a crimping portion 103. The crimping portion 103 is deformed by heat or pressure, or both, after the lens 102 is assembled to the lens holding frame 101, and functions to prevent the lens 102 from coming off in the optical axis direction.

[0016] The lens 102 has a first outer diameter portion 109, a second outer diameter portion 110, and an optical axis abutment portion 111. The first outer diameter portion 109 has a larger diameter than the second outer diameter portion 110. The second outer diameter portion 110 is located closer to the lens barrel mounting portion 106 than the first outer diameter portion 109 (on the side closer to the lens barrel mounting portion 106 in the optical axis direction than the first outer diameter portion 109). The first outer diameter portion 109 of the lens 102 is press-fitted into the lens press-fit portion 105 of the lens holding frame 101. The optical axis abutment portion 111 abuts against the lens barrel mounting portion 106.

[0017] Next, the structure and surface distortion of lens unit 100 will be described with reference to Fig. 1. Fig. 1 is an enlarged view of a main part of lens unit 100, and corresponds to the part enclosed by the dashed line in Fig. 2. Force F1 indicated by an arrow in Fig. 1 shows a schematic representation of a force that lens 102 receives from lens press-fitting portion 105 in a direction perpendicular to the optical axis (radial direction) when lens 102 is press-fitted into lens holding frame 101. Force F2 shows a force that lens 102 receives from crimping portion 103. Force F3 shows a force that lens 102 receives from lens holding frame 101, which is a reaction force to arrow F2.

[0018] The forces that the lens 102 receives from the lens holding frame 101 are forces F1, F2, and F3, and the forces F1, F2, and F3 are also the main factors related to the surface distortion of the lens 102. In addition, the influence of friction (not shown) at each contact portion, represented by friction μF1 due to the force F1, is considered, but since the amount of influence is minute, the explanation will focus on the main factors, forces F1, F2, and F3.

[0019] Here, if the lens 102 is considered to be a beam having a certain thickness, the dashed line in FIG. 1 indicates the neutral axis. The neutral axis in this embodiment is a line connecting points that do not expand or contract when a moment is applied, and when the lens 102 receives the force F1, distortion occurs in each area of ​​the lens 102 according to the distance from the neutral axis in the optical axis direction. The lens 102 in this embodiment is a biconcave lens in which the magnitude of curvature of the optically effective surface on the object side (surface R1) and the optically effective surface on the image plane side (R2) is the same. In this configuration, the dashed line (position x1 of the center of gravity of the lens in the optical axis direction) extending from the center of gravity of the lens 102 in the direction perpendicular to the optical axis approximately coincides with the neutral axis. However, this embodiment is not limited to this, and the curvature of the R1 surface and the R2 surface may be different from each other, and one of the R1 surface or the R2 surface may be a convex surface like a meniscus lens. In other words, the lens 102 only needs to have at least one surface that is concave. In this embodiment, the center of gravity of the lens 102 refers to a point at which the first moment of area at the center of an axis passing through that point is zero.

[0020] The inner diameter side cylindrical portion 104 constitutes a lens storage portion, and in order to incorporate the lens 102, it is generally necessary for the diameter to increase in the direction opposite to the optical axis direction of the lens barrel attachment portion 106 (however, a recess may be formed in a portion). This tendency is particularly prominent in resin lens barrels made by injection molding, in order to avoid undercuts. For this reason, in this embodiment, the lens press-fit portion 105 is provided adjacent to the lens barrel attachment portion 106 in the optical axis direction. Note that in this embodiment, the lens press-fit portion 105 is disposed in the same phase as the lens barrel attachment portion 106 in the rotational direction around the optical axis, but the phase may be shifted.

[0021] The first outer diameter portion 109 is press-fitted into the lens press-fit portion 105, and in this embodiment, the range of the contact area between the lens press-fit portion 105 and the first outer diameter portion 109 is the contact range A in the optical axis direction. In this embodiment, the center of gravity of the lens 102 (position x1 of the center of gravity of the lens in the optical axis direction) is located within the contact range A. At this time, the radius of the second outer diameter portion 110 is set to be approximately 0.05 mm smaller than the radius of the first outer diameter portion 109 so that the second outer diameter portion 110 does not contact the lens press-fit portion 105, and is set so that a gap of 0.02 mm or more is provided even including tolerances. Therefore, the contact range A can be controlled by the shape of the lens 102. In this embodiment, the contact range A is set to be within the range of 0.3 mm to 2.0 mm so that the pressure does not increase while maintaining stability due to the press-fitting.

[0022] 4(a) to (c) are explanatory diagrams of surface distortion caused by press-fitting when the position of contact area A between the lens holding frame 101 and lens 102 is changed. The lower rows in Fig. 4(a) to (c) show the position of contact area A, and the upper rows in Fig. 4(a) to (c) show the amount of surface distortion of the lens 102. In detail, the amount of displacement at each radius and angle when the apex of the R1 surface as viewed from the object side is set to displacement 0 is expressed on a gray scale (unit: mm). A positive value indicates deformation towards the lens body mounting part 106, and a negative value indicates deformation in the opposite direction to the lens body mounting part 106.

[0023] FIG. 4(a) shows a case where the contact area A is located in a range overlapping with the position x1 of the center of gravity of the lens in the optical axis direction as shown in FIG. 1. FIG. 4(b) shows a case where the contact area A is located closer to the lens barrel 106 than the position x1 of the center of gravity of the lens in the optical axis direction. FIG. 4(c) shows a case where the contact area A is located on the opposite side of the lens barrel 106 in the optical axis direction than the position x1 of the center of gravity of the lens in the optical axis direction. FIG. 4(a) shows the smallest amount of surface distortion, and FIGS. 4(b) and (c) show that the signs are reversed and the direction of the surface distortion is reversed, but the surface distortion is large. In other words, by including the position x1 of the center of gravity of the lens in the optical axis direction within the contact area A, it is possible to suppress the surface distortion.

[0024] 5(a) and (b) are explanatory diagrams of surface distortion when the thickness (wall thickness) of the inner diameter side cylindrical portion 104 of the lens holding frame 101 is changed. The thickness (average thickness) of the inner diameter side cylindrical portion 104 on the lens body attachment portion 106 side is t1, and the thickness (average thickness) of the inner diameter side cylindrical portion 104 on the opposite side to the lens body attachment portion 106 is t2, and surface distortion is expressed when the thicknesses t1 and t2 are changed. FIG. 5(a) shows the case where the thickness t2 is thicker than the thickness t1 as shown in FIG. 1. FIG. 5(b) shows the case where the thickness t1 is thicker than the thickness t2. In the configuration of FIG. 5(b), the strength of the side where the lens body attachment portion 106 exists is stronger than the configuration of FIG. 5(a), so a large amount of surface distortion occurs (the darker area of ​​the gray scale is large). For this reason, it is preferable that the inner diameter side cylindrical portion 104 satisfies the following conditional formula (1), where t1 is the average thickness on the lens barrel attachment portion 106 side and t2 is the average thickness on the opposite side of the flange portion 108.

[0025] t1 <t2 ···(1) With this configuration, it is possible to more effectively suppress surface distortion.

[0026] 6(a) to 6(c) are explanatory diagrams of surface distortion during press-fitting when the optical axis direction range C of the flange portion 108 (the range in the optical axis direction of the flange portion 108) is shifted. FIG. 6(a) shows a case where the optical axis direction range C of the flange portion 108 coincides with the optical axis direction position x1 of the lens center of gravity as shown in FIG. 1. FIG. 6(b) shows a case where the optical axis direction range C of the flange portion 108 is located on the lens barrel mounting portion 106 side with respect to the position x1 of the lens center of gravity. FIG. 6(c) shows a case where the optical axis direction range C of the flange portion is located on the opposite side to the lens barrel mounting portion 106 with respect to the position x1 of the lens center of gravity.

[0027] 6(a)-(c), it can be seen that surface distortion is most suppressible in FIG. 6(a). It can be seen that the direction of surface distortion in FIG. 6(g) is the opposite direction to that in FIG. 6(a) and (b). That is, by including the position x1 of the center of gravity of the lens in the optical axis direction range C of the flange portion 108, it is possible to suppress surface distortion more effectively. In other words, by including the position x1 of the center of gravity of the lens in the optical axis direction range C of the flange portion 108, it is possible to make the strength of both sides of the flange portion 108 close, and the balance of the optical axis direction of deformation during press-fitting is improved, and it is possible to suppress deformation in which the lens 102 becomes bow-shaped. In this configuration, the lens press-fit portion 105 is divided into multiple ranges rather than the entire inner diameter. For this reason, the surface distortion of the lens 102 is not uniform at the angle around the optical axis, and distorted surface distortion occurs. More specifically, it is divided into three parts every 120 degrees, and the surface distortion is also symmetrical every 120 degrees.

[0028] Next, the surface distortion caused by the forces F2 and F3 will be described in detail. For ease of explanation, the forces F2 and F3 when the lens unit 200 in the second embodiment is fixed by the pressing ring (ring member) 112 will be described first. When the lens 102 is fixed by the pressing ring 112, the lens holding frame 101, the lens 102, and the pressing ring 112 are each deformed by the axial force caused by the tightening force. At this time, the return force and the frictional force generated at each contact point including the threaded portion are balanced, so that an elastic force due to the deformation is always applied.

[0029] The same is true when fixing lens 102 with crimping portion 103 as in this embodiment; heat and pressure are applied by the tool used for crimping, causing the lens holding frame 101 and lens 102 to deform, and when the heat subsides, the lens is held in the deformed state, resulting in an elastic force being applied.

[0030] In this case, when the lens body attachment portion 106 is divided into a plurality of ranges as in this embodiment, the forces are balanced in the same cross section because the crimped portion 103 is on the opposite side of the lens 102 at the location where the lens body attachment portion 106 is present. However, in a phase where the lens body attachment portion 106 does not exist, the forces are not balanced in the same cross section, and the force from the lens body attachment portion 106, which is out of phase, must be used to balance the forces, which increases the distortion of the lens 102. For this reason, the surface distortion of the lens 102 is not uniform at angles around the optical axis, and distorted surface distortion occurs. More specifically, the lens body attachment portion 106 is divided into three parts every 120 degrees, and the surface distortion is also symmetrical every 120 degrees.

[0031] Figures 7(a) and (b) are diagrams showing the relationship between the distance (radial distance) from the optical axis O of the position that regulates the optical axis direction of lens 102 and surface distortion. Figure 7(a) shows the structure shown in Figure 1. Even if the abutting part of crimping part 103 and lens barrel attachment part 106 are present in the same cross section, if the distance between the two is far from the optical axis O as shown in Figure 7(b), lens 102 will be deformed into a bow shape.

[0032] Here, the difference (diameter difference) between the radius of the first outer diameter portion 109 and the radius of the second outer diameter portion 110 is y1 (mm). Also, the difference (diameter difference) between the radius of the first outer diameter portion 109 and the radius of the tip of the contact portion (crimping portion 103) for holding the lens 102 from the opposite side to the lens body mounting portion 106, that is, the difference in distance from the optical axis O to the lens press-fitting portion 105 and the inner diameter portion of the crimping portion 103, is B (mm). At this time, in order to reduce the surface distortion of the lens 102, it is necessary to make the difference y1 smaller than the difference B. However, if y1=0, the lens press-fitting portion 105 and the second outer diameter portion 110 will be fitted together, and the surface distortion due to the press-fitting will increase. For this reason, in this embodiment, the following conditional formula (2) is satisfied.

[0033] 0 <y1<B ···(2) By satisfying conditional expression (2), it is possible to suppress distortion due to press-fitting while suppressing bow-shaped deformation of the lens 102. In this manner, the difference (B) in the radial distance between the first outer diameter portion 109 and the tip of the contact portion is greater than the difference (y1) in the radial distance between the first outer diameter portion 109 and the second outer diameter portion 110. In this embodiment, as described above, y1 is set to be 0.02 mm or more including the tolerance. Figures 7(a) and (b) show distortion when force F2 is applied. It can be seen that surface distortion is further suppressed in Figure 7(a), which satisfies conditional expression (2). Preferably, the range of conditional expression (2) is set as shown in the following conditional expression (2a).

[0034] 0.02 <y1<0.5B ···(2a) As described above, as shown in Fig. 4, in order to suppress deformation due to force F1, it is necessary that the position x1 of the lens center of gravity in the optical axis direction is included within the contact range A. However, if the difference in radius between the first outer diameter portion 109 and the second outer diameter portion 110 is increased for this purpose, as shown in Fig. 7, there is a possibility that deformation due to force F2 during crimping or when tightening the presser ring, which will be described later, will become large, and therefore it is necessary to satisfy conditional formula (2). In other words, by satisfying both conditions, it is possible to provide a lens unit that can effectively suppress surface distortion of the lens.

[0035] Second Embodiment Next, a lens unit 200 according to a second embodiment of the present invention will be described with reference to Fig. 8 and Fig. 9. Fig. 8 is a cross-sectional view of lens unit 200 according to this embodiment, taken along a plane parallel to optical axis O. Fig. 9 is an enlarged view of a main part of lens unit 200, which corresponds to the part enclosed by the dashed line in Fig. 8.

[0036] Lens unit 200 of this embodiment differs from lens unit 100 of the first embodiment in that it has a pressing ring 112 for pressing lens 102 from the side opposite lens barrel attachment portion 106, instead of crimping portion 103. Other basic configurations of lens unit 200 are common to lens unit 100 of the first embodiment, and therefore description thereof will be omitted.

[0037] The pressing ring 112 has a lens pressing portion (contact portion) 115 that contacts the lens 102 on the opposite side in the optical axis direction to the lens barrel mounting portion 106 with the lens 102 sandwiched therebetween. The pressing ring 112 also has a threaded portion 114 that screws into the lens holding frame 101. In this embodiment, the difference B in conditional expressions (2) and (2a) is the difference between the radius of the first outer diameter portion 109 and the radius of the tip of the contact portion (lens pressing portion 115) for pressing the lens 102 from the opposite side to the lens barrel mounting portion 106. According to this embodiment, like the first embodiment, it is possible to provide a lens unit that can effectively suppress surface distortion of the lens.

[0038] Next, a digital still camera (imaging device) 10 using the lens unit of each embodiment will be described with reference to Fig. 10. Fig. 10 is a schematic diagram of the imaging device 10. In Fig. 10, 13 is a camera body, and 11 is a lens device equipped with the lens unit 100 of the first embodiment or the lens unit 200 of the second embodiment. 12 is an imaging element (photoelectric conversion element) such as a CCD sensor or a CMOS sensor that is built into the camera body 13 and receives an optical image formed by the lens device 11 and performs photoelectric conversion. The camera body 13 may be a so-called single-lens reflex camera having a quick-turn mirror, or may be a so-called mirrorless camera not having a quick-turn mirror.

[0039] According to each embodiment, it is possible to provide a lens unit and an imaging device capable of reducing the surface distortion of the lens that occurs when the lens is fixed to the lens holding frame.

[0040] Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications and changes are possible within the scope of the gist of the present invention.

[0041] For example, the second cylindrical portion and the flange portion may have the same thickness without any boundary therebetween. Also, a third cylindrical portion may be provided to reduce the thickness of the lens holding frame as shown in FIG. [Explanation of symbols]

[0042] 100, 200 Lens Unit 101 Lens holding frame 102 Lens 103 Crimping part (contact part) 104 Inner diameter cylindrical portion (first cylindrical portion) 105 Lens press-fit part (press-fit part) 106 Lens body attachment part (contact part) 107 Outer diameter cylindrical portion (second cylindrical portion) 108 Flange 109 First outer diameter 110 Second outer diameter 115 Lens holding part (contact part)

Claims

1. Lenses and a lens holding frame for holding the lens; the lens has a first outer diameter and a second outer diameter; The lens holding frame is a first cylindrical portion that houses the lens; A second cylindrical portion located on an outer diameter side of the first cylindrical portion; a flange portion provided between the first cylindrical portion and the second cylindrical portion; a contact portion that contacts the lens in the optical axis direction; a contact portion for pressing the lens from the opposite side to the abutment portion, the first cylindrical portion is provided with a press-fit portion into which the first outer diameter portion is press-fitted, The first outer diameter portion has a larger diameter than the second outer diameter portion, the second outer diameter portion is located closer to the abutment portion than the first outer diameter portion, In the optical axis direction, the center of gravity of the lens is located within a range of a contact area between the press-fit portion and the first outer diameter portion, When a difference between a radius of the first outer diameter portion and a radius of the second outer diameter portion is y1, and a difference between the radius of the first outer diameter portion and a radius of a tip end of the contact portion is B, 0<y1<B A lens unit characterized by satisfying the following conditional expressions:

2. 0.02<y1<0.5B 2. The lens unit according to claim 1, wherein the following condition is satisfied:

3. 3. The lens unit according to claim 1, wherein the lens is fixed in the radial direction to the lens holding frame by being press-fitted due to elastic deformation.

4. the lens holding frame has a crimping portion for holding the lens from the side opposite to the contact portion, 4. The lens unit according to claim 1, wherein the contact portion is the crimped portion.

5. 5. The lens unit according to claim 1, wherein the flange portion is a circumferential portion extending from the first cylindrical portion toward the second cylindrical portion.

6. 6. The lens unit according to claim 1, wherein the center of gravity of the lens is located within a range of the flange portion in the optical axis direction.

7. A lens; a lens holding frame for holding the lens; the lens has a first outer diameter and a second outer diameter; The lens holding frame is a first cylindrical portion that houses the lens; A second cylindrical portion located on an outer diameter side of the first cylindrical portion; a flange portion provided between the first cylindrical portion and the second cylindrical portion; a contact portion that contacts the lens in the optical axis direction, the first cylindrical portion is provided with a press-fit portion into which the first outer diameter portion is press-fitted, The first outer diameter portion has a larger diameter than the second outer diameter portion, the second outer diameter portion is located closer to the abutment portion than the first outer diameter portion, In the optical axis direction, the center of gravity of the lens is located within a range of a contact area between the press-fit portion and the first outer diameter portion, When a difference between a radius of the first outer diameter portion and a radius of the second outer diameter portion is y1, and a difference between the radius of the first outer diameter portion and a radius of a tip of a contact portion for pressing the lens from the side opposite to the abutment portion is B, 0<y1<B The conditional expression is satisfied. a pressing ring for pressing the lens from the side opposite to the contact portion; the contact portion is a lens pressing portion of the pressing ring, the flange portion is a circumferential portion extending from the first cylindrical portion toward the second cylindrical portion, the center of gravity of the lens is located within a range of the flange portion in the optical axis direction, The lens unit according to claim 1, wherein the first cylindrical portion is located at a position closer to the abutment portion with respect to the flange portion and at a position farther from the abutment portion with respect to the flange portion.

8. When a thickness of the first cylindrical portion at a position closer to the abutment portion with respect to the flange portion is t1, and a thickness of the first cylindrical portion at a position farther from the abutment portion with respect to the flange portion is t2, t1<t2 8. The lens unit according to claim 1, wherein the following condition is satisfied:

9. 9. The lens unit according to claim 1, wherein at least one surface of the lens is concave.

10. An imaging element; An imaging device comprising the lens unit according to claim 1 .

Images