Lens barrel and image pickup apparatus

Abstract

To eliminate backlash in a circumferential direction between barrel members in a lens barrel.SOLUTION: A lens barrel (1) includes a first barrel (15) including a focusing lens on an inner diameter side, a second barrel (14) disposed on an outer side in a radial direction of the first barrel (15) and having a linear guide portion along an optical axis, and a first protrusion (104,105) provided on the first barrel (15) and disposed so as to protrude from the first barrel (15), wherein the first protrusion moves while abutting on the linear guide portion (141) when the first barrel (15) moves in an optical axis direction with respect to the second barrel (14).SELECTED DRAWING: Figure 2

Description

[Technical Field]

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

[0002] The lens barrel needs to be prevented from rattling. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 7-120651 Summary of the Invention

[0004] The lens barrel of the first aspect comprises a first tube including a focusing lens on its inner diameter side, a second tube arranged radially outside the first tube and having a linear guide section along the optical axis, and a first protrusion provided on the first tube and arranged to protrude from the first tube, and the first protrusion moves while abutting against the linear guide section when the first tube moves in the optical axis direction relative to the second tube. [Brief explanation of the drawings]

[0005] [Figure 1] 1 is a cross-sectional view showing the lens barrel 1 of the first embodiment, illustrating a state in which the focal length is different between the upper and lower portions. [Figure 2] 1 is a partial perspective view of the linearly moving barrel 15 as seen from the outer periphery side, and the fixed barrel 14 positioned on the outer periphery of the linearly moving barrel 15 is indicated by a dotted line. [Figure 3] FIG. 3 is an exploded perspective view of the backlash-removing structure 100 in FIG. 2. [Figure 4] FIG. 10 is a side view showing a part of the internal barrel configuration of a lens barrel 201 according to a second embodiment. [Figure 5] FIG. 2 is an exploded view showing a state in which a rotary barrel 213 is arranged on the outer periphery of a fixed barrel 214. [Figure 6] FIG. 5 is a partial perspective view of a state in which a fixed barrel 214 is removed from FIG. 4. [Figure 7] 7 is an exploded perspective view of a backlash-removing structure 250, which will be described later, in the state of FIG. 6. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0006] (First embodiment) The lens barrel 1 of the first embodiment will be described below with reference to the drawings etc. Fig. 1 is a cross-sectional view showing the lens barrel 1 of the first embodiment, with the upper and lower parts in Fig. 1 showing different focal lengths. The lens barrel 1 has a lens mount section 11 on the right side of the figure, and is an interchangeable lens barrel 1 that can be attached to and detached from a body mount section (not shown) provided on the camera body 2. However, the present invention is not limited to this, and the lens barrel may be integrated with the camera body 2. Hereinafter, the left side of the drawing along the optical axis OA will be referred to as the subject side, and the right side of the drawing will be referred to as the image side.

[0007] The lens barrel 1 comprises, from the outer periphery, a focus ring 12, a rotating cylinder 13 that is arranged on the inner periphery of the focus ring 12 on the subject side and rotates integrally with the focus ring 12, a fixed cylinder 14 that is arranged on the inner periphery of the rotating cylinder 13 and extends further toward the image side than the rotating cylinder 13, and a linear-movement cylinder 15 that is arranged on the inner periphery of the rotating cylinder 13 and the fixed cylinder 14 and moves in a straight line as the rotating cylinder 13 rotates.

[0008] In this embodiment, the lens barrel 1 is a two-group fixed focal length lens, comprising a first lens group L1 and a second lens group L2. However, the lens barrel 1 is not limited to a two-group fixed focal length lens. For example, it may be a zoom lens, or may be composed of more groups. The first lens group L1 includes a first-first lens group L11, a second-first lens group L12, a third-first lens group L13, a fourth-first lens group L14, a fifth-first lens group L15, a sixth-first lens group L16, and a seventh-first lens group L17. The outer periphery of the 1-1st group lens L11 is held by a 1-1st group lens holding frame 21, the outer periphery of the 2-1st group lens L12 is held by a 2-1st group lens holding frame 22, the outer periphery of the 3-1st group lens L13 is held by a 3-1st group lens holding frame 23, the outer periphery of the 4-1st group lens L14 is held by a 4-1st group lens holding frame 24, the outer periphery of the 5-1st group lens L15 is held by a 5-1st group lens holding frame 25, the outer periphery of the 6-1st group lens L16 is held by a 6-1st group lens holding frame 26, and the outer periphery of the 7-1st group lens L17 is held by a 7-1st group lens holding frame 27.

[0009] The 3-1st group lens holding frame 23, the 4-1st group lens holding frame 24, and the 5-1st group lens holding frame 25 are fixed to a second rectilinearly movable barrel 32 disposed on their outer peripheries. The second rectilinearly movable barrel 32 is screwed to the rectilinearly movable barrel 15. Therefore, when the linear cylinder 15 moves straight, the second linearly movable cylinder 32 moves straight, which causes the 3-1st group lens holding frame 23, the 4-1st group lens holding frame 24, and the 5-1st group lens holding frame 25 to move straight, and therefore the 3-1st group lens L13, the 4-1st group lens L14, and the 5-1st group lens L15 to move straight.

[0010] The 1-1st group lens holding frame 21 and the 2-1st group lens holding frame 22 are fixed to a first rectilinearly movable barrel 31 disposed on their outer peripheries. The first rectilinearly movable barrel 31 is screwed to the tip of the second rectilinearly movable barrel 32 on the subject side. Therefore, when the rectilinear cylinder 15 moves straight, the first rectilinearly movable cylinder 31 moves straight together with the second rectilinearly movable cylinder 32, which causes the 1-1st group lens holding frame 21 and the 2-1st group lens holding frame 22 to move straight, and therefore the 1-1st group lens L11 and the 2-1st group lens L12 to move straight.

[0011] The 6-1st group lens holding frame 26 and the 7-1st group lens holding frame 27 are fixed to the linear motion barrel 15. Therefore, when the linear motion barrel 15 moves linearly, the 6-1st group lens holding frame 26 and the 7-1st group lens holding frame 27 move linearly, and therefore the 6-1st group lens L16 and the 7-1st group lens L17 move linearly. In other words, when the linear motion barrel 15 moves linearly, all of the first group lens L1 moves linearly.

[0012] The second lens group L2 is held by a second lens group holding frame 28, which is fixed to the image side of the fixed barrel 14.

[0013] (Fixed cylinder 14) As shown in Fig. 1, the fixed barrel 14 is a cylindrical member with a larger diameter on the subject side and a smaller diameter on the image side. However, the shape of the fixed barrel 14 is not limited to this, and the subject side and image side may have approximately the same diameter. Fig. 2 is a partial perspective view of the linear motion barrel 15 as seen from the outer periphery, with the fixed barrel 14 positioned on the outer periphery of the linear motion barrel 15 indicated by a dotted line. Fig. 3 is an exploded perspective view of the backlash-removing structure 100, which will be described later, in Fig. 2. "Backlash" refers to the relative movement between cylindrical parts that occurs due to manufacturing errors, clearances intentionally provided during mechanical design for assembly, etc. "Backlash elimination" refers to the elimination of this relative movement.

[0014] (Straight tube 15) 1, linear motion barrel 15 has a large diameter on the subject side and a small diameter on the image side, similar to fixed barrel 14, and is provided with threaded portion 15C at the subject side end which is even larger in diameter than the large diameter portion and has a helicoid thread on its outer periphery. Note that the shape of linear motion barrel 15 is not limited to this, and it may have a shape in which the subject side and image side have approximately the same diameter. The helicoid screw is threaded into a helicoid groove provided on the inner surface of the rotating barrel 13 on the subject side, and the helicoid screw moves along the helicoid groove when the rotating barrel 13 rotates. This causes the linear movement barrel 15 to move linearly (advance and retreat) in the direction of the optical axis OA relative to the fixed barrel 14 and the rotating barrel 13, which rotates relative to the fixed barrel 14 but does not move in the direction of the optical axis OA.

[0015] The upper part of FIG. 1 shows the state in which the amount of protrusion of the linear barrel 15 relative to the fixed barrel is smallest, with only the threaded portion 15C of the linear barrel 15 protruding from the first annular member 16 and the fixed barrel . 1 shows the state in which the amount of protrusion of linear-advancement barrel 15 relative to fixed barrel 14 is greatest, with threaded portion 15C of linear-advancement barrel 15 being farther away from first annular member 16 and fixed barrel 14 in the optical axis direction than in the state shown in the upper part of Fig. 1, and approximately half of the large-diameter portion of linear-advancement barrel 15 protruding toward the subject beyond first annular member 16 and fixed barrel 14. However, the tip of linear-advancement barrel 15 does not protrude beyond the tip of rotating barrel 13, and engagement between the helicoid groove of rotating barrel 13 and the helicoid thread of linear-advancement barrel 15 is maintained.

[0016] 2 and 3, recesses 152 extending in the direction of the optical axis OA are provided at three equally spaced locations in the circumferential direction on the outer surface of the linear barrel 15. Also, although only one location is shown by a dotted line in Fig. 2, linear grooves 141 are provided at three equally spaced locations in the circumferential direction on the inner diameter side of the fixed barrel 14.

[0017] A straight hole 151 is provided through the bottom surface of the recess 152 of the linear motion cylinder 15. The straight hole 151 is located approximately in the center of the longitudinal direction of the recess 152. Circular openings 153 are provided on both sides of the straight hole 151 on the bottom surface of the recess 152. Note that the straight hole 151 does not necessarily have to be a straight hole.

[0018] A backlash elimination structure 100 is disposed in the recess 152 of the linear motion barrel 15. The backlash elimination structure 100 includes a fixed member 101 extending in the optical axis direction within the recess 152, a moving member 102 extending in the optical axis OA direction within the recess 152 similarly to the fixed member 101 but being shorter than the fixed member 101, a spring 103 disposed between the fixed member 101 and the moving member 102, two inner bearings 104 protruding toward the outer diameter side, and two outer bearings 105 disposed outside the inner bearing 104 and protruding toward the outer diameter side similarly to the inner bearing 104.

[0019] (Fixing member 101) The fixed member 101 is a long, thin member extending in the optical axis OA direction within the recess 152. The fixed member 101 includes a fixed-side opposing portion 101a located approximately in the center in the longitudinal direction, and fixed-side bearing mounting portions 101b extending in the longitudinal direction from both ends of the fixed-side opposing portion 101a. An inner bearing movement elongated hole 101c and an outer bearing fixing hole 101d are provided to penetrate each of the two fixed-side bearing mounting portions 101b from the fixed-side opposing portion 101a side. The two inner bearing movement elongated holes 101c are each elongated holes that are long in the short direction of the fixed member 101 (the circumferential direction centered on the optical axis).

[0020] (moving member 102) The movable member 102 is a long and narrow member extending in the optical axis OA direction within the recess 152, and is shorter than the fixed member 101. The movable member 102 has a movable-side opposing part 102a at the center in the longitudinal direction. The movable-side opposing part 102a has approximately the same length as the fixed-side opposing part 101a, and is arranged to face the fixed-side opposing part 101a in the circumferential direction. The moving member 102 has moving-side bearing attachment portions 102b extending in the longitudinal direction from both ends of the moving-side opposing portion 102a. An inner bearing fixing hole 102c is provided through each of the two moving-side bearing attachment portions 102b. The movable-side bearing attachment portion 102b is provided so as to be closer to the linear cylinder 15 (inner diameter side) in the radial direction than the fixed-side bearing attachment portion 101b. In other words, the movable-side bearing attachment portion 102b is disposed between the fixed-side bearing attachment portion 101b and the linear cylinder 15.

[0021] The movable member 102 is arranged in the recess 152 of the linear cylinder 15, and the fixed member 101 is arranged so that the fixed side bearing mounting portion 101b is arranged on top of the movable side bearing mounting portion 102b and so that the movable side opposing portion 102a and the fixed side opposing portion 101a face each other. At this time, two springs 103 are arranged between the fixed-side opposing part 101a and the moving-side opposing part 102a. The springs 103 are compression springs and are arranged so as to extend in the circumferential direction (along the circumferential direction). In other words, the springs 103 bias the fixed member 101 (fixed-side opposing part 101a) and the moving member 102 (moving-side opposing part 102a) in the circumferential direction.

[0022] (inner bearing 104) The distance between the two inner bearing movement elongated holes 101c in the optical axis OA direction is approximately equal to the distance between the two inner bearing fixing holes 102c in the optical axis direction. The central shaft of the inner bearing 104 is fixed to the inner bearing fixing hole 102c through the inner bearing moving elongated hole 101c. At this time, the outer periphery of the inner bearing 104 protrudes from the moving-side opposing portion 102 a of the moving member 102 in the circumferential direction.

[0023] Here, the inner bearing movement elongated hole 101c is an elongated hole extending in the short-side direction of the fixed member 101, and therefore the inner bearing 104 fixed to the inner bearing fixing hole 102c of the movable member 102 is movable in the long-axis direction of the inner bearing movement elongated hole 101c (the circumferential direction of the lens barrel). In other words, the inner bearing movement elongated hole 101c is formed in the shape of an elongated hole that is long in the circumferential direction of the lens barrel (the direction in which the inner bearing 104 and the movable member 102 can move) so that the inner bearing 104 can move in the circumferential direction. Note that the inner bearing movement elongated hole 101c is not limited to being an elongated hole, and may be formed in any way so that the inner bearing 104 can move in the circumferential direction. For example, it may be a notch cut out in the short-side direction of the fixed member 101 (the circumferential direction centered on the optical axis).

[0024] (Outer bearing 105) The distance between the two outer bearing fixing holes 101d in the optical axis OA direction is equal to the distance between the two openings 153 provided in the recess 152 of the linearly moving barrel 15 in the optical axis OA direction. The central shaft of the outer bearing 105 is attached to the linear cylinder 15 (opening 153) through the outer bearing fixing hole 101d. As a result, the fixed member 101 is fixed to the linear movement barrel 15 by the outer bearing 105 .

[0025] In this way, the fixed member 101 is fixed to the linear movement barrel 15. On the other hand, the movable member 102 is movable relative to the fixed member 101. Therefore, the movable member 102 is pressed against the fixed side opposing part 101a in the circumferential direction of the lens barrel 1 by the biasing force of the spring 103, and is movable in the circumferential direction. Furthermore, the outer periphery of the inner bearing 104 protrudes in the circumferential direction beyond the moving-side opposing part 102a of the moving member 102, so the inner bearing 104 abuts against one of the side surfaces of the linear groove 141 of the fixed barrel 14. The backlash-removing mechanism 100 attached to the linear barrel 15 moves in the linear groove 141 when the linear barrel 15 moves in the optical axis direction. At this time, because the inner bearing 104 abuts against the linear groove 141, the linear barrel 15 can move smoothly without any backlash.

[0026] The outer periphery of the outer bearing 105 protrudes in the circumferential direction from the fixed-side opposing part 101a of the fixed member 101. Therefore, the outer bearing 105 abuts against the other side surface of the rectilinear groove 141 of the fixed barrel 14. Therefore, when the backlash eliminating mechanism 100 moves within the rectilinear groove 141, the outer bearing 105 abuts against the rectilinear groove 141, thereby suppressing backlash and enabling smooth movement. However, the present invention is not limited to this, and the outer bearing 105 may be configured not to abut against the rectilinear groove 141. Furthermore, since the movable-side bearing attachment portion 102b is sandwiched between the fixed-side bearing attachment portion 101b and the linearly moving cylinder 15, the movable member 102 can be prevented from floating.

[0027] As described above, according to this embodiment, the outer periphery of the inner bearing 104 abuts against one of the side surfaces of the linear groove 141 of the fixed barrel 14, and the fixed barrel 14 is biased in the circumferential direction by the spring force against the linear barrel 15. Therefore, it is possible to eliminate circumferential backlash between the fixed barrel 14 and the linear barrel 15 that moves linearly relative to the fixed barrel 14. Furthermore, by eliminating backlash using the linear groove 141, it is possible to appropriately eliminate backlash between barrels that do not rotate relative to each other. Eliminating backlash between barrels that do not rotate relative to each other improves optical performance. The linear barrel 15 holds multiple lens groups inside via the second linearly movable barrel 32, etc. By eliminating backlash in the circumferential direction of the linear barrel 15, it is possible to suppress tilting and backlash of the lens groups held inside the linear barrel 15, and the optical performance of the lens barrel 1 can be improved. In this embodiment, an example has been described in which the backlash-reducing structures 100 are provided in the recesses 152 provided at three evenly spaced locations in the circumferential direction, but this is not limiting. The recesses 152 may be provided at two or fewer locations, or at four or more locations. Furthermore, a plurality of recesses 152 and backlash-reducing structures 100 may be provided unevenly rather than evenly. In the embodiment, an example has been described in which the linear movement barrel 15 is disposed on the inner diameter side of the fixed barrel 14, but the linear movement barrel 15 may also be disposed on the outer diameter side of the fixed barrel 14. In that case, the inner bearing 104 and the outer bearing 104 may protrude on the inner diameter side and engage with the linear movement groove 141. In this case, the linear movement groove 141 is provided on the outer peripheral side of the fixed barrel 14. In the embodiment, an example has been described in which the fixed member 101 is fixed to the linear barrel 15 by the outer bearing 105, but the part corresponding to the fixed member 101 may be integrally formed with the linear barrel 15.

[0028] (Second embodiment) Next, a lens barrel 201 according to a second embodiment will be described with reference to the drawings. Fig. 4 is a side view showing part of the internal barrel configuration of the lens barrel 201 according to the second embodiment. Like the lens barrel 1 according to the first embodiment, the lens barrel 201 according to the second embodiment also has a lens-side mount portion (not shown) and is an interchangeable lens barrel 201 that is detachable from a camera body (not shown). However, the present invention is not limited to this, and the lens barrel may be an interchangeable lens barrel that is integrated with the camera body.

[0029] The lens barrel 201 includes at least a fixed barrel 214 shown in FIG. 4, a linear barrel 215 that is disposed on the inner diameter side of the fixed barrel 214, holds the lens group M (shown in FIG. 6), and moves linearly relative to the fixed barrel 214, and a rotating / moving barrel 213 shown by dotted lines in FIG. 4 that is disposed on the outer diameter side of the fixed barrel 214, rotates relative to the fixed barrel 214, and moves in the direction of the optical axis OA.

[0030] Fig. 5 is an exploded view showing a state in which the rotating / moving barrel 213 is arranged on the outer periphery of the fixed barrel 214. Fig. 6 is a partial perspective view in which the rotating / moving barrel 213 and the fixed barrel 214 are indicated by dotted lines in a state in which the fixed barrel 214 has been removed from Fig. 4. Fig. 7 is an exploded perspective view showing a backlash-removing structure 250, which will be described later, in the state shown in Fig. 6.

[0031] (Rotating cylinder 213) Rotating barrel 213 is a barrel that moves in the direction of optical axis OA while rotating about optical axis OA by rotating a rotation operation unit (not shown) provided on lens barrel 201. Rotating barrel 213 has a circumferential groove 213a on its inner peripheral surface that extends in the circumferential direction around optical axis OA.

[0032] (Fixed tube 214) Although only one location is shown in the figure, the fixed barrel 214 has pairs of straight grooves, each consisting of a straight guide groove 214b extending along the optical axis OA and a straight groove 214a for removing backlash, provided at three equally spaced locations around the circumference.

[0033] (Straight tube 215) The linear barrel 215 holds the lens group M, and although only one location is shown in the drawing, it is provided with linear guide portions 230 and backlash-removing structures 250 at three locations evenly spaced in the circumferential direction.

[0034] (Straight guide part 230) The rectilinear guide part 230 includes a substantially rectangular rectilinear part 231 attached to the outer peripheral surface of the rectilinear barrel 215 so as to extend in the direction of the optical axis OA, and a rectilinear drive first bearing 232 fixed to the outer surface of the rectilinear part 231 so as to protrude radially outward. The rectilinear drive first bearing 232 engages with a circumferential groove 213a of the rotating barrel 213.

[0035] (250mm rattle structure) The backlash-removing structure 250 includes a two-stage bearing 251 fixed to the outer peripheral surface of the linear barrel 215 so as to protrude outward, a movable plate 252 attached to a side surface 215a of the linear barrel 215 that is perpendicular to the optical axis OA, a first fixed pin 253 and a second fixed pin 254 that pass through the movable plate 252 and are fixed to the side surface 215a of the linear barrel 215, a spring 255 that biases the second fixed pin 254 and the movable plate 252, and a pressure bearing 256 fixed to the movable plate 252.

[0036] (2-stage bearing 251) The two-stage bearing 251 has a two-stage structure including a fixed bearing 251a on the inner diameter side and a linear drive second bearing 251b on the outer diameter side, and is fixed to the outer peripheral surface of the linear cylinder 215 so as to protrude outward. The linear drive second bearing 251b is approximately the same radial distance from the optical axis OA as the linear drive first bearing 232 of the linear guide part 230, and is also located on the same circumference in the direction of the optical axis OA, and together with the linear drive first bearing 232, engages with the circumferential groove 213a of the rotating moving barrel 213. In this embodiment, the outer periphery of the fixed bearing 251a does not abut against the side surface of the linear groove 214a for removing backlash. However, this is not limitative and the fixed bearing 251a may abut against the other side surface of the linear groove 214a than the side surface that a pressure bearing 256 (described later) abuts against.

[0037] (Moving board 252) As shown in Figure 7, the moving plate 252 has a flat portion 252A on both sides in the longitudinal direction, with elongated holes 252a and 252b extending in the longitudinal direction, a bearing holding portion 252c that bends from one side of the flat portion 252A between the two elongated holes 252a and 252b and extends toward the image side at approximately a right angle to the flat portion 252A, and a spring hook portion 252d that bends from one end in the longitudinal direction of the flat portion 252A at approximately a right angle to the flat portion 252A and extends toward the back side like the bearing holding portion 252c.

[0038] (First fixing pin 253, second fixing pin 254) A first fixed pin 253 is inserted into the elongated hole 252b on the side where the spring hook portion 252d is provided, and the first fixed pin 253 passes through the elongated hole 252b and is fixed to the side surface 215a of the linear movement barrel 215. A second fixed pin 254 is inserted into the other elongated hole 252a, and the second fixed pin 254 passes through the elongated hole 242a and is fixed to the side surface 215a of the linear movement barrel 215. As a result, the moving plate 252 is arranged so that its longitudinal direction follows the circumferential direction of the linear movement barrel 215 and is movable in the circumferential direction.

[0039] (Spring 255) The second fixing pin 254 extends further toward the optical axis OA image side than the first fixing pin 253, and a tension spring 255 is attached between the second fixing pin 254 and a spring 255 hook portion.

[0040] (Pressure bearing 256) The pressure bearing 256 is fixed to the bearing holding portion 252 c of the moving plate 252 and protrudes outward from the linearly moving cylinder 215 .

[0041] A spring 255, one end of which is fixed to a second fixed pin 254 fixed to the linear cylinder 215 and the other end of which is fixed to a spring hook portion 252d of the moving plate 252, pulls the spring hook portion 252d, i.e., the moving plate 252, toward the second fixed pin 254 in the circumferential direction. At this time, the moving plate 252 is held by the first fixing pin 253 and the second fixing pin 254 so as to be movable in the circumferential direction relative to the linearly moving cylinder 215 within the range of the length of the major axes of the elongated holes 252a and 252b. Therefore, the movable plate 252 moves in the circumferential direction when pulled in the circumferential direction by the spring 255. As a result, the pressure bearing 256 also moves in the circumferential direction and abuts against the side surface of the linear groove 214a for removing backlash of the fixed cylinder 214.

[0042] When a rotation operation unit (not shown) provided on lens barrel 201 is rotated, rotational movement barrel 213 moves linearly in the direction of optical axis OA while rotating around optical axis OA. At this time, rectilinear drive first bearing 232 and rectilinear drive second bearing 251b are engaged with circumferential groove 213a provided on the inner peripheral surface of rotational movement barrel 213. rectilinear drive first bearing 232 and rectilinear drive second bearing 251b are fixed to rectilinear movement barrel 215, which is only capable of rectilinear movement without rotating. Therefore, rectilinear drive first bearing 232 and rectilinear drive second bearing 251b do not rotate around optical axis OA even when circumferential groove 213a rotates. However, the outer surfaces of the linear drive first bearing 232 and the linear drive second bearing 251b that are in contact with the circumferential groove 213a are rotatable about their respective central axes. Therefore, the linear barrel 215 provided with the linear drive first bearing 232 and the linear drive second bearing 251b can obtain a driving force in the direction of the optical axis OA without interfering with the circumferential groove 213a, i.e., the circumferential rotation of the rotating barrel 213.

[0043] At this time, the linear movement of the linear movement barrel 215 is guided by a linear movement guide groove 214 b provided in the fixed barrel 214 . At this time, the pressure bearing 256 attached to the linear barrel 215 abuts against the side surface of the linear groove 214a for removing backlash in the fixed barrel 214, eliminating any circumferential backlash between the fixed barrel 214 and the linear barrel 215. This makes it possible to prevent the lens group M of the linear barrel 215 from tilting, improving the optical performance of the lens barrel 1. Furthermore, by removing backlash using the linear groove 214a for removing backlash, it is possible to appropriately remove backlash between barrels that do not rotate relative to each other. Eliminating backlash between barrels that do not rotate relative to each other improves optical performance. In the embodiment, the configuration in which the linear guide portions 230 and the backlash-removing structures 250 are provided at three equally spaced locations in the circumferential direction has been described, but this is not limitative. The linear guide portions 230 and the backlash-removing structures 250 may be provided at two or less locations, or at four or more locations. They may also be provided unevenly. In the embodiment, an example has been described in which the linear barrel 215 is disposed on the inner diameter side of the fixed barrel 214, but the linear barrel 215 may also be disposed on the outer diameter side of the fixed barrel 214. In that case, the two-stage bearing 251 and the pressure bearing 256 may protrude on the inner diameter side and engage with the backlash-removing linear grooves 214a. Alternatively, the rotating barrel 213 may be disposed on the inner diameter side of the fixed barrel 214, and the two-stage bearing 251 and the pressure bearing 256 may engage with the backlash-removing linear grooves 214a and the circumferential groove 213a. In the embodiment, an example has been described in which the second fixing pin 254 is fixed to the linear movement barrel 215, but a configuration in which a portion corresponding to the second fixing pin 254 is integrally formed with the linear movement barrel 215 may also be used.

[0044] The present invention is not limited to the above-described embodiments, and any combination may be used. [Explanation of symbols]

[0045] L1: first group lens, L2: second group lens, M: lens group, OA: optical axis, 1: lens barrel, 13: rotating barrel, 14: fixed barrel, 15: linear barrel, 15C: threaded portion, 16: first annular member, 100: backlash removal structure, 101: fixed member, 101a: fixed side opposing portion, 101b: fixed side bearing mounting portion, 101c: inner bearing moving slot, 101d: outer bearing fixing hole, 102: moving member, 102a: moving side opposing portion, 102b: moving side bearing mounting portion, 102c: inner bearing fixing hole, 103: spring, 104: inner bearing, 105: outer bearing, 141: linear groove, 151: straight hole, 152: recess, 1 53: opening, 201: lens barrel, 213: rotating and moving barrel, 213a: circumferential groove, 214: fixed barrel, 214a: straight groove for use, 214b: straight guide groove, 215: straight barrel, 215a: side surface, 230: straight guide portion, 231: straight portion, 232: straight drive first bearing, 242a: oblong hole, 250: structure, 251: stepped bearing, 251a: fixed bearing, 251b: straight drive second bearing, 252: moving plate, 252A: flat portion, 252a: oblong hole, 252b: oblong hole, 252c: bearing holding portion, 252d: spring hook portion, 253: first fixed pin, 254: second fixed pin, 255: spring, 256: pressure bearing

Claims

[Claim 1] a first barrel including a focusing lens on its inner diameter side; a second barrel disposed radially outward of the first barrel and having a linear guide portion along the optical axis; a first protrusion provided on the first cylinder and arranged to protrude from the first cylinder; Equipped with The first protrusion moves while coming into contact with the linear guide portion when the first cylinder moves in the optical axis direction relative to the second cylinder. Lens barrel.

Images