Lens barrel

Abstract

To provide a lens barrel that can accurately adjust the position of a lens or a lens holding frame with a simple configuration.SOLUTION: A lens barrel comprises: a reference lens holding frame that holds a reference lens; an adjustment lens holding frame that holds an adjustment lens; and a sheet member that has a substantially ring shape and is clamped by the reference lens holding frame and the adjustment lens holding frame. The reference lens holding frame has at least two first clamping parts that clamp the sheet member with the adjustment lens holding frame. The adjustment lens holding frame has at least two second clamping parts that clamp the sheet member with the reference lens holding frame. The sheet member has a first sheet part that is clamped by the first clamping parts and the second clamping parts, and a second sheet part that is located between the first clamping parts and the second clamping parts. The width in a radial direction of the second sheet part is smaller than the width in a radial direction of the first sheet part.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a lens barrel, and more particularly to a lens barrel that performs a plurality of optical adjustments on a lens or a lens holding frame. [Background technology]

[0002] In some cases, a lens barrel is provided with an adjustment mechanism for adjusting the position of the lens or the lens holding frame in order to reduce the effects of manufacturing errors and assembly variations and to improve optical performance.

[0003] For example, Patent Document 1 discloses a lens barrel equipped with an adjustment mechanism that sandwiches a spacer having a predetermined thickness between lenses to enable adjustment of the distance between the lenses in the optical axis direction. Patent Document 2 discloses a lens barrel equipped with an adjustment mechanism that translates the lens to be adjusted along a plane intersecting the optical axis, enabling eccentric adjustment to align the optical axis of a reference lens with the optical axis of the lens to be adjusted. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2012-123220 A [Patent Document 2] JP 2018-021967 A Summary of the Invention [Problem to be solved by the invention]

[0005] In a lens barrel with high resolution performance, the required accuracy of the lens position is high, and there are cases where multiple position adjustments are required for the lens or the lens holding frame.

[0006] For example, first, a sheet member is sandwiched between an adjustment lens holding frame that holds a lens to be adjusted and a reference lens holding frame that holds a reference lens to adjust the gap, as in Patent Document 1. Then, as in Patent Document 2, it is possible to perform eccentricity adjustment by translating the adjustment lens holding frame along a plane that intersects with the optical axis relative to the reference lens holding frame.

[0007] However, if the sheet member is thin, it may be deformed and twisted due to the external force applied during the eccentricity adjustment. If the sheet member located between the receiving surfaces of the reference lens holding frame and the adjustment lens holding frame is twisted, the lens to be adjusted may be tilted relative to the reference lens. This may adversely affect the optical performance of the lens barrel.

[0008] SUMMARY OF THE PRESENT DISCLOSURE An object of the present invention is to provide a lens barrel that is simple in configuration and capable of adjusting the position of a lens or a lens holding frame with high accuracy. [Means for solving the problem]

[0009] In order to achieve the above-mentioned object, the lens barrel of the present invention is a lens barrel that adjusts the position of an adjustment lens by moving an adjustment lens holding frame that holds an adjustment lens in a direction intersecting an optical axis, and is equipped with a reference lens holding frame that holds a reference lens, the adjustment lens holding frame that holds the adjustment lens, and a sheet member that is approximately annular and is sandwiched between the reference lens holding frame and the adjustment lens holding frame, wherein the reference lens holding frame has at least two first clamping portions that clamp the sheet member between it and the adjustment lens holding frame, the adjustment lens holding frame has at least two second clamping portions that clamp the sheet member between it and the reference lens holding frame, the sheet member has a first sheet portion that is clamped by the first clamping portion and the second clamping portion, and a second sheet portion located between the first clamping portion and the second clamping portion, and the radial width of the second sheet portion is narrower than the radial width of the first sheet portion. Effect of the Invention

[0010] According to the present invention, it is possible to provide a lens barrel that is capable of adjusting the position of a lens or a lens holding frame with high accuracy using a simple configuration. [Brief description of the drawings]

[0011] [Figure 1] 1 is an exploded perspective view of an imaging device 1 according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is an exploded perspective view of the second lens group unit 50 according to the first embodiment of the present invention. [Diagram 3] 1 is a front view of a sheet member 51 according to a first embodiment of the present invention. [Figure 4] FIG. 2 is a diagram showing a reference lens holding frame 12b according to the first embodiment of the present invention. [Diagram 5] 1 is a diagram showing an adjustment lens holding frame 12a according to the first embodiment of the present invention. [Figure 6] 4A to 4C are diagrams showing the state of decentering adjustment of the second lens group unit 50 according to the first embodiment of the present invention. [Figure 7] 4 is a diagram showing an engagement state between the reference lens holding frame 12b and a sheet member 51 according to the first embodiment of the present invention. FIG. [Figure 8] FIG. 11 is a front view of a sheet member 151 according to a second embodiment of the present invention. [Figure 9] FIG. 11 is a front view of a sheet member 251 according to a third embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the dimensions, materials, and relative positions of components described in the following embodiments are arbitrary and can be changed according to the configuration of the device to which the present invention is applied or various conditions. Note that descriptions of parts that are not directly related to the present invention will be omitted and are not shown. Furthermore, for convenience of explanation, the shapes of parts may be described in a simplified manner.

[0013] <First embodiment> In this embodiment, an example of an embodiment of an imaging device to which the present invention is applied will be described. First, the configuration of the imaging device 1 will be described. Figs. 1(A) and (B) are exploded perspective views of the imaging device 1. Figs. 2(A) and (B) are exploded perspective views of the second lens group unit 50. Fig. 3 is a front view of the sheet member 51. Figs. 4(A) and (B) are views showing the reference lens holding frame 12b. Fig. 5 is a view showing the adjustment lens holding frame 12a.

[0014] The imaging device 1 includes a lens barrel 100, an imaging element unit 20, and an optical filter holding frame .

[0015] The lens barrel 100 has two fixed lens groups and three movable lens groups. The first lens group L1 and the fifth lens group L5 are fixed in the optical axis direction. The second lens group L2, the third lens group L3, and the fourth lens group L4 are movable in the optical axis direction. When zooming, the second lens group L2, the third lens group L3, and the fourth lens group L4 are moved in the optical axis direction, and when focusing, the fourth lens group L4 is moved in the optical axis direction.

[0016] The first lens retaining frame 11 holds the first lens group L1. The first lens retaining frame 11 is fixed to a front fixed frame 16 with screws (not shown). The fifth lens retaining frame 15 holds the fifth lens group L5. The fifth lens retaining frame 15 is fixed to a rear fixed frame 17 with screws (not shown). In addition, the front fixed frame 16 is coupled to the rear fixed frame 17 with screws (not shown).

[0017] 2, the second lens group unit 50 includes a second lens group L2, a second lens holding frame 12, an aperture unit 35, a sheet member 51, and a rack 31. The second lens group L2 is composed of an adjustment lens group L2a and a reference lens group L2b. The second lens holding frame 12 is composed of an adjustment lens holding frame 12a and a reference lens holding frame 12b.

[0018] The adjustment lens group L2a is held by an adjustment lens holding frame 12a. The adjustment lens group L2a needs to undergo interval adjustment in the optical axis direction and decentering adjustment with respect to the reference lens group L2b.

[0019] The reference lens group L2b is held by the reference lens holding frame 12b. The reference lens group L2b serves as a reference for the interval adjustment and decentering adjustment of the adjustment lens group L2a. As will be described in detail later, the interval adjustment and decentering adjustment are performed by adjusting the position of the adjustment lens holding frame 12a relative to the reference lens holding frame 12b. After the interval adjustment and decentering adjustment, the adjustment lens holding frame 12a is fixed to the reference lens holding frame 12b by an adhesive (not shown) and screws 36 as fastening members.

[0020] The adjustment lens holding frame 12a holds the adjustment lens group L2a. As shown in Figs. 2(A)(B) and 5, the adjustment lens holding frame 12a has surfaces S1, S2, S3, S4, S5, and S6 that are receiving surfaces for the reference lens holding frame 12b and are provided approximately evenly in a circumferential shape. The surfaces S1, S2, S3, S4, S5, and S6 are convex parts that protrude in the optical axis direction. In addition, the surfaces S1, S3, and S5 have through holes for the screws 36. As shown in Fig. 2(B), the adjustment lens holding frame 12a has cutouts N at positions facing the regions U12, U23, U34, U45, U56, and U61 of the sheet member 51 described later. The cutouts N are portions into which the sheet member 51 bends when the sheet member 51 described later is twisted. The cutout portion N is provided between the surface S1, the surface S2, the surface S3, the surface S4, the surface S5, and the surface S6. The surface S1, the surface S2, the surface S3, the surface S4, the surface S5, and the surface S6 are the second clamping portion. That is, the cutout portion N is provided between the second clamping portions. That is, the adjustment lens holding frame 12a has the surfaces S1, S2, S3, S4, S5, and S6 protruding from the reference surface A in the optical axis direction, and the cutout portion N recessed from the reference surface A in the optical axis direction. In addition, in the circumferential direction of the adjustment lens holding frame 12a, the surface S1, the reference surface A, the cutout portion N, the reference surface A, the surface S2, the reference surface A, the cutout portion N, the reference surface A, and the surface S3 are arranged in this order. That is, the reference surface A is arranged between the cutout portion N and the surfaces S1-S6. However, the reference surface A may not be provided, and the cutout portions N and the surfaces S1-S6 may be arranged alternately.

[0021] The reference lens holding frame 12b holds the reference lens group L2b. The reference lens holding frame 12b is supported by a guide bar 21 so as to be movable in the optical axis direction. The guide bar 22 engages with the U-shaped groove of the reference lens holding frame 12b and restricts the rotation of the reference lens holding frame 12b around the guide bar 22. The reference lens holding frame 12b is provided with surfaces T1, T2, T3, T4, T5, and T6, which are receiving surfaces for the adjustment lens holding frame 12a, at substantially equal intervals in a circumferential shape. The surfaces T1, T2, T3, T4, T5, and T6 are convex portions that protrude in the optical axis direction of the reference lens. The surfaces S1 and T1, S2 and T2, S3 and T3, S4 and T4, S5 and T5, and S6 and T6 are each formed to have substantially the same area. Furthermore, faces T1, T3, and T5 are provided with pilot holes for screws 36. Faces T1, T2, T3, T4, T5, and T6 form a first clamping portion.

[0022] 4, the reference lens holding frame 12b has engagement portions E1 and E2 that engage with a sheet member 51, which will be described later. The engagement portions E1 and E2 are inner walls of the reference lens holding frame 12b, and position the sheet member 51 relative to the reference lens holding frame 12b. A plurality of engagement portions E1 are provided along the circumferential direction. Furthermore, the engagement portions E1 protrude radially inward.

[0023] The rack 31 is fixed to the reference lens holding frame 12b in a state where it is biased in the optical axis direction and the rotational direction by a rack spring (not shown), and engages with a screw portion 27a of the stepping motor 27. The reference lens holding frame 12b moves in the optical axis direction via the rack 31 by the rotation of the screw portion 27a of the stepping motor 27.

[0024] Thereby, the second lens retaining frame 12 including the reference lens retaining frame 12b is movable in the optical axis direction between a first position closest to the imaging element 20a and a second position farthest from the imaging element 20a.

[0025] The aperture unit 35 adjusts the amount of light incident on the lens. The aperture unit 35 freely changes the size of the aperture diameter of the aperture 35a formed by aperture blades (not shown) by changing the input current input from the outside, thereby adjusting the amount of incident light. The aperture unit 35 is electrically connected to an aperture FPC 35b for inputting a current from the outside, and is drawn from inside the lens barrel 1 to the outside of the rear fixed frame 17 and connected to an external power source. The aperture FPC 35b gradually bends as the second lens group 12 moves from the second position farthest from the image sensor 20a to the first position closest to the image sensor 20a. The aperture unit 35 is fixed to the reference lens holding frame 12b with screws 37.

[0026] The sheet member 51 is a member that adjusts the distance between the adjustment lens holding frame 12a and the reference lens holding frame 12b. The sheet member 51 is made of, for example, a polyester film. The sheet member 51 is formed, for example, by punching a polyester film or etching stainless steel. The sheet member 51 is sandwiched between the adjustment lens holding frame 12a and the reference lens holding frame 12b.

[0027] As shown in FIG. 3, the sheet member 51 is substantially annular with a through hole in the center, and includes regions U1, U2, U3, U4, U5, and U6. The sheet member 51 further includes a region U12 between the regions U1 and U2, and a region U23 between the regions U2 and U3. The sheet member 51 further includes a region U34 between the regions U3 and U4, and a region U45 between the regions U4 and U5. The sheet member 51 further includes a region U56 between the regions U5 and U6, and a region U61 between the regions U6 and U1. Through holes for the screws 36 are formed in the regions U1, U3, and U5. The regions U12, U23, U34, U45, U56, and U61 are formed to have a smaller radial width than the regions U1, U2, U3, U4, U5, and U6. That is, the regions U12, U23, U34, U45, U56, and U61 have lower rigidity than the regions U1, U2, U3, U4, U5, and U6, and are easily deformed and twisted by external forces. The regions U1, U3, and U5 satisfy the above-mentioned relationship even if the size of the through hole for the screw 36 is subtracted as the radial width. The regions U12, U23, U34, U45, U56, and U61 of the sheet member 51 are not in contact with the adjustment lens holding frame 12a due to the cutout portion N of the adjustment lens holding frame 12a. The regions U1, U2, U3, U4, U5, and U6 are the first sheet portion. Region U12, region U23, region U34, region U45, region U56, and region U61 are the second sheet portion.

[0028] The third lens retaining frame 13 retains the third lens group L3. The third lens retaining frame 13 is supported by a guide bar 23 so as to be movable in the optical axis direction. The guide bar 24 engages with a U-shaped groove of the third lens retaining frame 13 and restricts the rotation of the third lens retaining frame 13 around the guide bar 24.

[0029] The rack 32 is fixed to the third lens retaining frame 13 in a state where it is biased in the optical axis direction and the rotational direction by a rack spring (not shown), and engages with a screw portion 28a of the stepping motor 28. The third lens retaining frame 13 moves in the optical axis direction via the rack 32 by rotation of the screw portion 28a of the stepping motor 28. This allows the third lens retaining frame 13 to move in the optical axis direction between a first position closest to the imaging element 20a and a second position farthest from the imaging element 20a.

[0030] The fourth lens retaining frame 14 retains the fourth lens group L4. The fourth lens retaining frame 14 is supported by a guide bar 23 so as to be movable in the optical axis direction. The guide bar 24 engages with a U-shaped groove of the fourth lens retaining frame 14 and restricts the rotation of the fourth lens retaining frame 14 around the guide bar 23.

[0031] The rack 33 is fixed to the fourth lens retaining frame 14 in a state where it is biased in the optical axis direction and the rotational direction by a rack spring (not shown), and engages with a screw portion 29a of the stepping motor 29. The fourth lens retaining frame 14 moves in the optical axis direction via the rack 33 by rotation of the screw portion 29a of the stepping motor 29. This allows the fourth lens retaining frame 14 to move in the optical axis direction between a first position closest to the imaging element 20a and a second position farthest from the imaging element 20a.

[0032] Guide bar 21, guide bar 22, guide bar 23, and guide bar 24 guide the movement of second lens group L2, third lens group L3, and fourth lens group L4 in the optical axis direction. Guide bar 21, guide bar 22, guide bar 23, and guide bar 24 are clamped and fixed between front fixed frame 16 and rear fixed frame 17.

[0033] The lens FPC 40 is connected to the stepping motor 27, the stepping motor 28, the stepping motor 29, and the stepping motor 30, and activates each of them when energized. The lens FPC 40 is also connected to the aperture FPC 35b of the aperture unit 35, and activates the aperture unit 35 when energized.

[0034] A photointerrupter (not shown) is mounted on the lens FPC 40. Stepping motors 27 and 28 control the positions of the second lens retaining frame 12 and the third lens retaining frame 13 based on the output of the photointerrupter (not shown). Stepping motors 29 and 30 control the positions of the fourth lens retaining frame 14 and the optical filter retaining frame 18 based on the output of the photointerrupter (not shown).

[0035] The imaging element unit 20 has an imaging element 20a, and is fixed to the imaging element unit holding frame 19 with screws (not shown). The imaging element unit 19 is coupled to the rear fixing frame 17 with screws (not shown).

[0036] Optical filter holding frame 18 holds infrared cut filter 38 and dummy glass 39, and is supported by guide bar 25 so as to be movable in a direction perpendicular to the optical axis. Guide bar 26 engages with a U-shaped groove in optical filter holding frame 18 to restrict rotation of optical filter holding frame 18 around guide bar 26. Guide bar 25 and guide bar 26 are clamped and fixed between rear fixed frame 17 and imaging element unit holding frame 19.

[0037] The rack 34 is fixed to the optical filter holding frame 18 in a state where it is biased in a direction perpendicular to the optical axis and in a rotational direction by a rack spring (not shown), and engages with the screw portion 30a of the stepping motor 30. The optical filter holding frame 18 moves in a direction perpendicular to the optical axis via the rack 34 by rotation of the screw portion 30a of the stepping motor 30. This makes it possible to switch between an infrared cut filter 38 and a dummy glass 39 as an optical filter on the optical path.

[0038] When the infrared cut filter 38 is inserted into the optical path and the dummy glass 39 is removed from the optical path, it is possible to collect visible light while cutting out infrared light. This state is an imaging mode called a day mode, which allows the subject to be photographed during the day. When the infrared cut filter 38 is removed from the optical path and the dummy glass 39 is inserted into the optical path, it is possible to collect infrared light in addition to visible light. This state is an imaging mode called a night mode, which allows the subject to be photographed at night.

[0039] Next, optical adjustment, which is the adjustment of the position of the second lens group unit 50, will be described.

[0040] The optical adjustment of the second lens group unit 50 is performed in the order of spacing adjustment and decentering adjustment. The spacing adjustment is a position adjustment between the adjustment lens holding frame 12a and the reference lens holding frame 12b in the optical axis direction of the second lens group unit 50. The decentering adjustment is a position adjustment of the adjustment lens holding frame 12a relative to the reference lens holding frame 12b in a direction perpendicular to the optical axis of the second lens group unit 50.

[0041] The gap adjustment is performed by sandwiching a sheet member 51 between the adjustment lens holding frame 12a and the reference lens holding frame 12b. A plurality of types of sheet members 51 are prepared with different thicknesses, and the sheet member 51 is selectively used according to the gap between the adjustment lens group L2a and the reference lens group L2b. The thickness of the sheet member 51 is determined by directly measuring the gap between the adjustment lens group L2a and the reference lens group L2b.

[0042] If it is difficult to directly measure the distance between the adjustment lens group L2a and the reference lens group L2b, the reference lens holding frame 12b may be attached to an adjustment tool (not shown). Then, the adjustment lens holding frame 12a may be temporarily fixed to the reference lens holding frame 12b by a temporary positioning mechanism (not shown), and the thickness of the sheet member 51 may be determined by measuring optical performance such as aberration and contrast.

[0043] Fig. 6 is a diagram showing the decentering adjustment of the second lens group unit 50. The decentering adjustment is performed by sandwiching a sheet member 51 having a thickness determined by the interval adjustment between the adjustment lens holding frame 12a and the reference lens holding frame 12b. In this state, as shown in Fig. 6, the position of the adjustment lens holding frame 12a is adjusted along a plane intersecting with the optical axis by three adjustment pins 60 provided on an adjustment tool (not shown).

[0044] The three adjustment pins 60 are arranged at approximately equal intervals in the circumferential direction centered on the optical axis, and abut against the outer peripheral surface of the adjustment lens holding frame 12a. A predetermined adjustment clearance is provided in the radial direction between the outer peripheral surface of the adjustment lens holding frame 12a and the inner peripheral surface of the reference lens holding frame 12b. Therefore, the position of the adjustment lens holding frame 12a can be changed by the amount of the adjustment clearance with respect to the reference lens holding frame 12b. Therefore, by changing the radial positions of the three adjustment pins 60, the position of the adjustment lens holding frame 12a can be adjusted along a plane intersecting the optical axis.

[0045] This decentering adjustment is performed by searching for the best position of the adjustment lens holding frame 12a while measuring optical performance such as aberration and contrast. After the decentering adjustment, the adjustment lens holding frame 12a is fixed to the reference lens holding frame 12b at the best position with an adhesive. The adhesive is, for example, an ultraviolet-curing adhesive, which is injected into three adhesive grooves G of the reference lens holding frame 12b, adheres to the outer circumferential surface of the adjustment lens holding frame 12a, and is cured by irradiation with ultraviolet light. In this embodiment, the adjustment lens holding frame 12a is fixed to the reference lens holding frame 12b with the adhesive, and then is further firmly fixed with three screws 36.

[0046] Next, the relationship between the reference lens holding frame 12b and the sheet member 51 will be described. Fig. 7 is a diagram showing an engagement state between the reference lens holding frame 12b and the sheet member 51. For the sake of explanation, the sheet member 51 is shown by a dotted line, and the surfaces T1, T2, T3, T4, T5, and T6 of the reference lens holding frame 12b are hatched. The adjustment lens holding frame 12a is not shown.

[0047] 7, the sheet member 51 engages with the inner walls of the reference lens holding frame 12b at engagement portions E1 and E2, and its position relative to the reference lens holding frame 12b is determined. The engagement portions E1 are provided near the surfaces T1, T2, T3, T4, T5, and T6 of the reference lens holding frame 12b, and regulate the radial position of the sheet member 51. The engagement portion E2 is provided near the surface T1, and regulates the rotation of the sheet member 51 in the circumferential direction.

[0048] When the adjustment lens retaining frame 12a is sandwiched and fixed between the reference lens retaining frame 12b, the region U1 of the sheet member 51 is sandwiched between the surfaces S1 and T1, and the region U2 is sandwiched between the surfaces S2 and T2. When the adjustment lens retaining frame 12a is sandwiched and fixed between the reference lens retaining frame 12b, the region U3 of the sheet member 51 is sandwiched between the surfaces S3 and T3, the region U4 is sandwiched between the surfaces S4 and T4, the region U5 is sandwiched between the surfaces S5 and T5, and the region U6 is sandwiched between the surfaces S6 and T6.

[0049] Next, the twisting of the sheet member 51 during eccentricity adjustment will be described. When the adjustment lens holding frame 12a is moved on the sheet member 51 during eccentricity adjustment, a frictional force is generated between the sheet member 51 and the adjustment lens holding frame 12a. For example, as shown in FIG. 7, when the adjustment lens holding frame 12a (not shown) is moved in the direction of the arrow, a frictional force is applied to the sheet member 51 between the adjustment lens holding frame 12a in the direction of the arrow. As a result, the movement of the area in the direction of the arrow (upper half in the figure) is restricted and the position is unlikely to shift because the frictional force applied is toward the engagement part E1. However, the movement of the area in the opposite direction to the arrow (lower half in the figure) is not restricted and the position may shift because the frictional force applied is away from the engagement part E1. In this case, a compressive force is applied near the boundary between the two areas, and the areas U23 and U56 with low rigidity are deformed and twisted.

[0050] In this way, when an external force is applied to the sheet member 51, the low rigidity region is twisted, but the high rigidity region is not twisted. Therefore, no twisting occurs in the high rigidity region of the sheet member 51 sandwiched between the receiving surfaces of the adjustment lens holding frame 12a and the reference lens holding frame 12b, and there is no effect on the optical performance.

[0051] Furthermore, if the twist in that region is large, the region of low rigidity of the sheet member 51 is twisted so as to be positioned within the cutout portion N shown in Fig. 2(B). This can reduce interference with the adjustment lens holding frame 12a.

[0052] According to the present invention, by controlling the location where twisting occurs in the spacing-adjusting sheet member to a location that does not affect optical performance, it is possible to provide a lens barrel that enables spacing adjustment and eccentricity adjustment to be performed with high precision on the lens or lens holding frame with a simple configuration.

[0053] Second Embodiment In this embodiment, an example of an embodiment of a lens barrel to which the present invention is applied, which is different from the first embodiment, will be described. This embodiment differs from the first embodiment only in the shape of the portion of the sheet member with low rigidity. FIG. 8 is a front view of sheet member 151.

[0054] The sheet member 151 of this embodiment has regions V1, V2, V3, V4, V5, and V6. The sheet member 151 also has a region V12 between regions V1 and V2, and a region V23 between regions V2 and V3. The sheet member 151 also has a region V34 between regions V3 and V4, a region V45 between regions V4 and V5, a region V56 between regions V5 and V6, and a region V61 between regions V6 and V1. Regions V12, V23, V34, V45, V56, and V61 are substantially U-shaped.

[0055] When the adjustment lens holding frame 12a is sandwiched and fixed to the reference lens holding frame 12b, the sheet member 151 has the region V1 sandwiched between the surface S1 and the surface T1, and the region V2 sandwiched between the surface S2 and the surface T2. When the adjustment lens holding frame 12a is sandwiched and fixed to the reference lens holding frame 12b, the sheet member 151 has the region V3 sandwiched between the surface S3 and the surface T3, the region V4 sandwiched between the surface S4 and the surface T4, the region V5 sandwiched between the surface S5 and the surface T5, and the region V6 sandwiched between the surface S6 and the surface T6. Through holes for the screws 36 are formed in the regions V1, V3, and V5. As shown in FIG. 8, the region V12 is formed to bend in the radial direction so as to have a region having a smaller radial width than the regions V1 and V2, and to have the regions V121 and V122 extending in the radial direction.

[0056] As shown in FIG. 8, the region V23 is formed by bending in the radial direction so as to have a region whose radial width is smaller than the regions V2 and V3 and to have regions V231 and V232 extending in the radial direction. As shown in FIG. 8, the region V34 is formed by bending in the radial direction so as to have a region whose radial width is smaller than the regions V3 and V4 and to have regions V341 and V342 extending in the radial direction. As shown in FIG. 8, the region V45 is formed by bending in the radial direction so as to have regions V451 and V452 whose radial width is smaller than the regions V4 and V5 and to have a region extending in the radial direction. As shown in FIG. 8, the region V56 is formed by bending in the radial direction so as to have a region whose radial width is smaller than the regions V5 and V6 and to have regions V561 and V562 extending in the radial direction. As shown in FIG. 8, region V61 is formed to curve radially so as to have a region whose radial width is smaller than regions V1 and V6 and so as to have regions V611 and V612 extending in the radial direction.

[0057] Furthermore, the regions V12, V23, V34, V45, V56, and V61 are formed so that their widths in the extension direction are substantially constant. The regions V12, V23, V34, V45, V56, and V61 have lower rigidity than the regions V1, V2, V3, V4, V5, and V6, and are easily deformed and twisted by external forces. The regions V1, V3, and V5 satisfy the above-mentioned relationship even if the size of the through hole for the screw 36 is subtracted as the radial width.

[0058] As described above, the sheet member of this embodiment has a radially curved area of ​​low rigidity, and therefore has a shape that is more prone to deformation and twisting when frictional forces are applied during eccentricity adjustment, compared to the sheet member of the first embodiment.

[0059] According to the present invention, by controlling the location where twisting occurs in the spacing-adjusting sheet member to a location that does not affect optical performance, it is possible to provide a lens barrel that enables spacing adjustment and eccentricity adjustment to be performed with high precision on the lens or lens holding frame with a simple configuration.

[0060] <Third embodiment> In this embodiment, an example of an embodiment of a lens barrel to which the present invention is applied, which is different from the first and second embodiments, will be described. This embodiment differs from the first and second embodiments only in the shape of the portion of the sheet member with low rigidity. Figure 9 is a front view of sheet member 251.

[0061] The sheet member 251 of this embodiment has regions W1, W2, W3, W4, W5, and W6. The sheet member 251 of this embodiment has a region W12 between the regions W1 and W2, a region W23 between the regions W2 and W3, and a region W34 between the regions W3 and W4. The sheet member 251 of this embodiment has a region W45 between the regions W4 and W5, a region W56 between the regions W5 and W6, and a region W61 between the regions W6 and W1. The regions W12, W23, W34, W45, W56, and W61 are bent in two places and have two bent portions.

[0062] In the sheet member 251 of this embodiment, when the adjustment lens holding frame 12a is fixed to the reference lens holding frame 12b, the region W1 is sandwiched between the surface S1 and the surface T1. When the adjustment lens holding frame 12a is fixed to the reference lens holding frame 12b, the region W2 is sandwiched between the surface S2 and the surface T2. When the adjustment lens holding frame 12a is fixed to the reference lens holding frame 12b, the region W3 is sandwiched between the surface S3 and the surface T3. When the adjustment lens holding frame 12a is fixed to the reference lens holding frame 12b, the region W4 is sandwiched between the surface S4 and the surface T4. When the adjustment lens holding frame 12a is fixed to the reference lens holding frame 12b, the region W5 is sandwiched between the surface S5 and the surface T5, and the region W6 is sandwiched between the surface S6 and the surface T6. Through holes for the screws 36 are formed in the regions W1, W3, and W5. As shown in FIG. 9, the region W12 is formed in a detour in the circumferential direction so as to have a region whose radial width is smaller than the regions W1 and W2 and to have a region W121 extending in the radial direction. As shown in FIG. 9, the region W23 is formed in a detour in the circumferential direction so as to have a region whose radial width is smaller than the regions W2 and W3 and to have a region W231 extending in the radial direction. The region W34 is formed in a detour in the circumferential direction so as to have a region whose radial width is smaller than the regions W3 and W4 and to have a region W341 extending in the radial direction. As shown in FIG. 9, the region W45 is formed in a detour in the circumferential direction so as to have a region whose radial width is smaller than the regions W4 and W5 and to have a region W451 extending in the radial direction. 9, region W56 is formed to bend in the circumferential direction so as to have a region whose radial width is smaller than regions W5 and W6 and to have region W561 extending in the radial direction. Also, as shown in FIG 9, region W61 is formed to bend in the circumferential direction so as to have a region whose radial width is smaller than regions W1 and W6 and to have region W611 extending in the radial direction.

[0063] Furthermore, the regions W12, W23, W34, W45, W56, and W61 are formed so that their widths in the extension direction are substantially constant. That is, the regions W12, W23, W34, W45, W56, and W61 have lower rigidity than the regions W1, W2, W3, W4, W5, and W6, and are easily deformed and twisted by external forces. The regions W1, W3, and W5 satisfy the above-mentioned relationship as their radial widths, even if the size of the through holes for the screws 36 is subtracted.

[0064] As described above, the sheet member of this embodiment has a circumferentially curved area of ​​low rigidity, and therefore has a shape that is more prone to deformation and twisting when frictional forces are applied during eccentricity adjustment, compared to the sheet member of the first embodiment.

[0065] According to the present invention, by controlling the location where twisting occurs in the spacing-adjusting sheet member to a location that does not affect optical performance, it is possible to provide a lens barrel that enables spacing adjustment and eccentricity adjustment to be performed with high precision on the lens or lens holding frame with a simple configuration.

[0066] <Embodiment 4> In this embodiment, an example of an embodiment of a lens barrel to which the present invention is applied, which is different from the first, second and third embodiments, will be described. Unlike the first, second and third embodiments, this embodiment does not have an adjustment lens holding frame. Therefore, during decentering adjustment, the position of the adjustment lens is adjusted. That is, during decentering adjustment, the position of the adjustment lens is adjusted along a plane intersecting the optical axis by three adjustment pins 60. After decentering adjustment of the position of the adjustment lens, the adjustment lens is fixed to the reference lens holding frame by a pressing member. Specifically, a pressing member is arranged so as to cover the adjustment lens from the optical axis direction, and the adjustment lens is sandwiched between the pressing member and the reference lens holding frame.

[0067] According to the present invention, by controlling the location where twisting occurs in the spacing-adjusting sheet member to a location that does not affect optical performance, it is possible to provide a lens barrel that enables spacing adjustment and eccentricity adjustment to be performed with high precision on the lens or lens holding frame with a simple configuration.

[0068] In the above embodiment, the timing when the sheet member twists is described as the time of eccentricity adjustment as an example, but other possible timings include the timing when the adjustment lens holding frame 12a is placed on the reference lens holding frame 12b via the sheet member, and the timing when the adjustment lens holding frame 12a is fixed to the reference lens holding frame 12b with the screws 36.

[0069] In the above embodiment, the interval adjustment and decentering adjustment are performed on the adjustment lens group L2a and the reference lens group L2b, but this is not limited to the above. For example, in order to perform decentering adjustment on the entire system of the first lens group L1, the second lens group L2, the third lens group L3, the fourth lens group L4, and the fifth lens group L5, the adjustment may be performed in the assembled state of the lens barrel. If it is difficult to perform the adjustment in the assembled state, an adjustment tool that can reproduce a state corresponding to the assembled state may be used.

[0070] In the above embodiment, one sheet member is used for the gap adjustment, but multiple sheets may be used. For example, two sheet members each having a thickness of 10 μm may be used to adjust the gap by 20 μm.

[0071] Furthermore, although the adjustment lens holding frame 12a has the cutout portion N, the reference lens holding frame 12b may have the cutout portion N. Furthermore, the cutout portion may be provided in both the adjustment lens holding frame 12a and the reference lens holding frame 12b.

[0072] 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. [Explanation of symbols]

[0073] 1. Imaging device L2a Adjustment Lens Group L2b Reference Lens Group 12a Adjustment lens holder 12b Reference lens holder 50 2nd lens group unit 51 Sheet material 60 Adjustment pin 100 Lens barrel 151 Sheet material 251 Sheet material

Claims

1. A lens barrel in which an adjustment lens holding frame that holds an adjustment lens is moved in a direction intersecting with an optical axis to adjust the position, a reference lens holding frame for holding a reference lens; an adjustment lens holding frame for holding the adjustment lens; a sheet member having a substantially annular shape and sandwiched between the reference lens holding frame and the adjustment lens holding frame; the reference lens holding frame has at least two first clamping portions that clamp the sheet member between the reference lens holding frame and the adjustment lens holding frame, the adjustment lens holding frame has at least two second clamping portions that clamp the sheet member between the adjustment lens holding frame and the reference lens holding frame, the sheet member has a first sheet portion that is sandwiched by the first sandwiching portion and the second sandwiching portion, and a second sheet portion that is located between the first sandwiching portion and the second sandwiching portion, A lens barrel, wherein a width in a radial direction of the second seat portion is narrower than a width in a radial direction of the first seat portion.

2. 2. The lens barrel according to claim 1, wherein a distance between the reference lens holding frame and the adjustment lens holding frame in the optical axis direction is adjusted by a thickness of the sheet member.

3. The first sheet portion of the sheet member is provided in a circumferential manner in a plurality of positions, The lens barrel according to claim 1 , wherein a plurality of the first clamping portions are provided circumferentially so as to correspond to the plurality of first seat portions, respectively.

4. The first sheet portion of the sheet member is provided in a circumferential manner in a plurality of positions, The lens barrel according to claim 1 , wherein a plurality of the second clamping portions are provided circumferentially so as to correspond to the plurality of first seat portions, respectively.

5. 2. The lens barrel according to claim 1, wherein the sheet member engages with the reference lens holding frame in the vicinity of the first clamping portion of the reference lens holding frame.

6. The lens barrel according to claim 1 , wherein the adjustment lens holding frame has a notch between the second clamping portions.

7. 2. The lens barrel according to claim 1, wherein the first clamping portion of the reference lens holding frame is a convex portion that protrudes in the optical axis direction of the reference lens.

8. 2. The lens barrel according to claim 1, wherein the second clamping portion of the adjustment lens holding frame is a convex portion that protrudes in the optical axis direction of the reference lens.

9. 2. The lens barrel according to claim 1, wherein the first clamping portion is disposed opposite the second clamping portion, and the first clamping portion and the opposing second clamping portion each have approximately the same area.

10. 2. The lens barrel according to claim 1, wherein the reference lens holding frame and the adjustment lens holding frame are fixed to each other by an adhesive.

11. 2. The lens barrel according to claim 1, wherein the reference lens holding frame and the adjustment lens holding frame are fixed together by a fastening member.

12. The lens barrel according to claim 1 , wherein the second seat portion has a region extending in a radial direction.

13. The lens barrel according to claim 1 , wherein the second seat portion is curved.

14. A lens barrel in which an adjustment lens is moved in a direction intersecting an optical axis to adjust the position, a reference lens holding frame for holding a reference lens; a sheet member having a substantially annular shape and sandwiched between the reference lens holding frame and the adjustment lens; Equipped with the reference lens holding frame has at least two first clamping portions that clamp the sheet member between the reference lens holding frame and the adjustment lens, the adjustment lens has a second clamping portion that clamps the sheet member between the adjustment lens and the reference lens holding frame, the sheet member has a first sheet portion that is sandwiched by the first sandwiching portion and the second sandwiching portion, and a second sheet portion that is located between the first sandwiching portion and the second sandwiching portion, A lens barrel, wherein a width in a radial direction of the second seat portion is narrower than a width in a radial direction of the first seat portion.

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