Lens barrel

Abstract

To provide a lens barrel that can improve impact resistance while improving assembly efficiency and yield.SOLUTION: The lens barrel comprises: a first guide bar that movably supports a first holding member for holding a first lens and a second holding member for holding a second lens; and a second guide bar that restricts rotation of each holding member around the first guide bar. The first holding member includes: a first fitting part that fits to the first guide bar and a first groove part that engages with the second guide bar. The second holding member includes: a second fitting part that fits to the first guide bar and a second groove part that engages with the second guide bar. One of the first fitting parts is located between the second fitting parts, and one of the second fitting parts is located between the first fitting parts. The engaging parts of the first and second holding members engage with each other with a gap formed therebetween in a direction orthogonal to an optical axis direction, and the contact parts of the first and second holding members come into contact with each other in the optical axis direction so that the first and second lenses do not touch while the engaging parts are engaged.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to a lens barrel in which fitting portions of sleeves of two lens movement frames are alternately arranged with respect to one guide bar. [Background technology]

[0002] In a typical lens barrel mounted on a surveillance camera or the like, the inclination of a lens movement frame, which is supported by a guide bar so as to be movable in the optical axis direction, with respect to the optical axis direction affects optical performance. Patent Document 1 discloses a configuration in which, in order to reduce the inclination of the lens movement frame, two fitting parts provided on the sleeves of two lens movement frames are fitted to the same guide bar so as to sandwich one of the fitting parts of the other sleeve.

[0003] Furthermore, in a lens barrel, when an impact causes a lens movement frame to bend or move in the optical axis direction, it is necessary to prevent adjacent lenses from coming into contact and being damaged. Patent Document 2 discloses a configuration for improving the impact resistance of the lens barrel, in which when an impact brings two optical members into close proximity with each other, an abutting member that moves integrally with one optical member abuts against the other optical member, thereby preventing the two optical members from coming into contact with each other. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 2776160 [Patent Document 2] Patent No. 6305051 Summary of the Invention [Problem to be solved by the invention]

[0005] In the configuration of Patent Document 1, when assembling, it is necessary to insert the same guide bar into the fitting portion provided on each sleeve with the two lens movement frames overlapped. In the configuration of Patent Document 1, when the lenses held by the two lens movement frames are close to each other, if the two lens movement frames are overlapped with a large deviation in their relative positions, the adjacent lenses may come into contact and be damaged.

[0006] Furthermore, in the configuration of Patent Document 2, since the optical member and the abutting member come into contact with each other, there is a risk that the optical member may be damaged depending on the material of the abutting member.

[0007] An object of the present invention is to provide a lens barrel that can improve the ease of assembly and yield while also improving impact resistance. [Means for solving the problem]

[0008] A lens barrel according to one aspect of the present invention has a first holding member that holds a first lens, a second holding member that holds a second lens arranged adjacent to the first lens in the optical axis direction, a first guide bar that supports the first and second holding members movably in the optical axis direction, and a second guide bar that restricts rotation of the first and second holding members around the first guide bar, the first holding member having two first engagement portions that engage with the first guide bar at positions spaced apart in the optical axis direction and a first groove portion that engages with the second guide bar, and the second holding member has two first engagement portions that engage with the first guide bar at positions spaced apart in the optical axis direction and a first groove portion that engages with the second guide bar. and a second groove portion that engages with the second guide bar, one of the first mating portions is located between the second mating portions in the optical axis direction, one of the second mating portions is located between the first mating portions in the optical axis direction, the first holding member has a first engagement portion and a first abutment portion, the second holding member has a second engagement portion and a second abutment portion, the first and second engagement portions engage with each other with a gap formed therebetween in a direction perpendicular to the optical axis direction, and the first and second abutment portions abut in the optical axis direction such that the first lens and the second lens do not come into contact when the first and second engagement portions are engaged. Effect of the Invention

[0009] According to the present invention, it is possible to provide a lens barrel that can improve the ease of assembly and yield while also improving impact resistance. [Brief description of the drawings]

[0010] [Figure 1] FIG. 2 is an exploded perspective view of the lens barrel of the first embodiment. [Diagram 2] FIG. 2 is an exploded perspective view of the second group unit of the first embodiment. [Diagram 3] 4 is a perspective view showing the relationship between a third lens group moving frame and a fourth lens group moving frame in the first embodiment. FIG. [Figure 4] 1 is a cross-sectional view of a common guide bar for a sleeve of a third lens group moving frame and a sleeve of a fourth lens group moving frame in the first embodiment. FIG. [Diagram 5] 1 is a perspective view of a state in which a third lens group moving frame and a fourth lens group moving frame of the first embodiment are overlapped. FIG. [Figure 6] 4 is a cross-sectional view taken along the optical axis of the first embodiment in a state where the third lens group movement frame and the fourth lens group movement frame are overlapped. FIG. [Figure 7] 4 is an explanatory diagram of a detailed shape of a third lens group moving frame in the first embodiment. FIG. [Figure 8] 4 is an explanatory diagram of a detailed shape of a fourth lens group moving frame in the first embodiment. FIG. [Figure 9] 11 is a diagram showing a state in which the first third group abutting portion and the first fourth group abutting portion of Example 1 come into contact with each other. FIG. [Figure 10] FIG. 11 is a perspective view of a state in which a third lens group moving frame and a fourth lens group moving frame of the second embodiment are overlapped. [Figure 11] 11 is a cross-sectional view taken along the optical axis of a state in which a third lens group movement frame and a fourth lens group movement frame of the second embodiment are overlapped. FIG. [Figure 12] 10 is an explanatory diagram of a detailed shape of a third lens group moving frame in the second embodiment. FIG. [Figure 13] 10 is an explanatory diagram of a detailed shape of a fourth lens group moving frame in the second embodiment. FIG. [Figure 14]13 is a diagram showing a state in which the first third group abutting portion and the fourth group abutting portion of Example 2 come into contact with each other. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals are used to refer to the same components, and duplicated descriptions will be omitted.

[0012] In each embodiment, the subject side (object side) in the optical axis direction is defined as the front side, and the imaging surface side (image side) is defined as the rear side. EXAMPLES

[0013] 1(A) and 1(B) are exploded perspective views of the lens barrel 1. The lens barrel 1 has a first lens group L1, a second lens group L2, a third lens group L3, a fourth lens group L4, and a fifth lens group L5. The first lens group L1 and the fifth lens group L5 are fixed lenses, and the second lens group L2, the third lens group L3, and the fourth lens group L4 are movable lenses. 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. Each 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 includes at least one lens.

[0014] The first lens group L1 is held by a first lens group fixing frame 10. The first lens group fixing frame 10 is fixed to a front fixing frame 80 with screws (not shown).

[0015] The second lens group L2 is held by a second lens group moving frame 20. The second lens group moving frame 20 is supported by a guide bar 82 so as to be movable in the optical axis direction, and its rotation around the guide bar 82 is restricted by a guide bar 83.

[0016] The third lens group L3 is held by a third lens group movement frame 30. The third lens group movement frame 30 is supported by a common guide bar (first guide bar) 84 so as to be movable in the optical axis direction, and its rotation around the common guide bar 84 is restricted by a common guide bar (second guide bar) 85.

[0017] The fourth lens group L4 is held by a fourth lens group movement frame 40. The fourth lens group movement frame 40 is supported by a common guide bar 84 so as to be movable in the optical axis direction, and its rotation around the common guide bar 84 is restricted by a common guide bar 85.

[0018] The fifth lens group L5 is held by a fifth lens group fixing frame 50. The fifth lens group fixing frame 50 is fixed to a rear fixing frame 81 with screws (not shown).

[0019] In this embodiment, one of the third lens group movement frame 30 and the fourth lens group movement frame 40 functions as a first holding member that holds a first lens, and the other functions as a second holding member that holds a second lens disposed adjacent to the first lens in the optical axis direction. In this embodiment, a case will be described in which the third lens group movement frame 30 functions as the first holding member, and the fourth lens group movement frame 40 functions as the second holding member, but the present invention is not limited to this.

[0020] The front fixed frame 80 is joined to the rear fixed frame 81 by screws (not shown). The guide bars 82, 83 and the common guide bars 84, 85 are sandwiched between the front fixed frame 80 and the rear fixed frame 81 and fixed thereto.

[0021] The infrared cut filter 61 and the dummy glass 62 are held by the optical filter holding frame 60. The optical filter holding frame 60 is supported by a guide bar 86 so as to be movable in a direction perpendicular to the optical axis, and the rotation around the guide bar 86 is restricted by a guide bar 87. This allows the infrared cut filter 61 and the dummy glass 62 to be switched as optical filters on the optical path. When the infrared cut filter 61 is inserted into the optical path and the dummy glass 62 is removed from the optical path, it is possible to collect visible light while cutting infrared light. This state is a shooting mode called a day mode, which allows shooting of a subject during the day. When the infrared cut filter 61 is removed from the optical path and the dummy glass 62 is inserted into the optical path, it is possible to collect infrared light in addition to visible light. This state is a shooting mode called a night mode, which allows shooting of a subject at night.

[0022] The imaging element unit 71 includes an imaging element 71a, and is fixed to the imaging element unit holding frame 70 with screws (not shown). The imaging element unit holding frame 70 is joined to a rear fixed frame 81 with screws (not shown). The guide bars 86 and 87 are clamped and fixed between the imaging element unit holding frame 70 and the rear fixed frame 81.

[0023] The lens FPC 88, the stepping motor 29, the stepping motor 39, the stepping motor 49, and the stepping motor 69 are fixed to the rear fixed frame 81. The lens FPC 88 is connected to the stepping motors 29, 39, 49, and 69, and activates each of them when electricity is applied. The lens FPC 88 is also connected to the aperture FPC 24b of the aperture unit 24, and activates the aperture unit 24 when electricity is applied. Furthermore, a photointerrupter (not shown) is mounted on the lens FPC 88. The stepping motors 29, 39, 49, and 69 control the positions of the second lens group moving frame 20, the third lens group moving frame 30, the fourth lens group moving frame 40, and the optical filter holding frame 60, respectively, based on the output of the photointerrupter (not shown).

[0024] 2 is an exploded perspective view of the second unit 2. The second unit 2 has a second lens L2, a second lens movement frame 20, a sheet member 23, an aperture unit 24, and a rack 27. The second lens L2 has a second adjustment lens L2a and a second reference lens L2b. The second lens movement frame 20 has a second adjustment lens holding frame 21 and a second reference lens holding frame 22.

[0025] The second-group adjustment lens L2a is held by a second-group adjustment lens holding frame 21, and needs to undergo spacing adjustment and decentering adjustment with respect to the second-group reference lens L2b. The second-group reference lens L2b is held by a second-group reference lens holding frame 22, and serves as a reference for the spacing adjustment and decentering adjustment of the second-group adjustment lens L2a.

[0026] The interval adjustment is performed by sandwiching a sheet member 23 between the second group adjustment lens holding frame 21 and the second group reference lens holding frame 22. The sheet member 23 is selected from a plurality of sheet members each having a different thickness according to the interval between the second group adjustment lens L2a and the second group reference lens L2b. The sheet member 23 is formed, for example, by punching a polyester film or etching a stainless steel. If it is difficult to directly measure the interval between the second group adjustment lens L2a and the second group reference lens L2b, the sheet member 23 may be selected by another method. For example, the second group reference lens holding frame 22 may be attached to an adjustment tool, the second group adjustment lens holding frame 21 may be temporarily fixed to the second group reference lens holding frame 22 by a temporary positioning mechanism, and the optical performance such as aberration and contrast may be measured to select the sheet member 23.

[0027] The eccentricity adjustment is performed by adjusting the position of the second adjustment lens holding frame 21 relative to the second reference lens holding frame 22 in a plane perpendicular to the optical axis with an adjustment pin provided in the adjustment tool while the sheet member 23 is sandwiched between the second adjustment lens holding frame 21 and the second reference lens holding frame 22. For example, the adjustment tool has three adjustment pins, which are arranged at approximately equal intervals along the circumferential direction centered on the optical axis and abut against the outer circumferential surface of the second adjustment lens holding frame 21. A predetermined adjustment clearance is provided in the radial direction between the outer circumferential surface of the second adjustment lens holding frame 21 and the inner circumferential surface of the second reference lens holding frame 22. The position of the second adjustment lens holding frame 21 can be changed by the amount of this adjustment clearance within the second reference lens holding frame 22. By changing the radial position of the adjustment pin, the position of the second adjustment lens holding frame 21 can be adjusted in a plane perpendicular to the optical axis. The decentering adjustment is performed by a method of finding the best position for the second group adjustment lens holding frame 21 while measuring optical performance such as aberration and contrast. The second group adjustment lens holding frame 21 is fixed to the second group reference lens holding frame 22 at the best position with an adhesive. The adhesive is, for example, an ultraviolet-curing adhesive, which is injected into three adhesion grooves 22a of the second group reference lens holding frame 22 and adheres to the outer circumferential surface of the second group adjustment lens holding frame 21, and is cured by being irradiated with ultraviolet rays. In this embodiment, the second group adjustment lens holding frame 21 is fixed to the second group reference lens holding frame 22 with the adhesive, and then fixed with three screws 25.

[0028] The second group reference lens holding frame 22 includes a sleeve 220 and a groove 223. The sleeve 220 includes a first second group fitting portion 221 and a second second group fitting portion 222. The first second group fitting portion 221 is located at the front end (front end portion) of the sleeve 220, and the second second group fitting portion 222 is located at the rear end (rear end portion) of the sleeve 220. The guide bar 82 is inserted through the first second group fitting portion 221 and the second second group fitting portion 222. That is, the first second group fitting portion 221 and the second second group fitting portion 222 have circular holes that fit with the guide bar 82. As a result, the second group reference lens holding frame 22 is supported so as to be movable in the optical axis direction. In this embodiment, the diameter of the hole formed in the first second group fitting portion 221 is smaller than the diameter of the hole formed in the second second group fitting portion 222. The guide bar 83 is inserted into the groove portion 223. As a result, the rotation of the second group reference lens holding frame 22 around the guide bar 82 is restricted.

[0029] The rack 27 is fixed to the second reference lens holding frame 22 in a state where it is biased in the optical axis direction and a direction perpendicular to the optical axis by a biasing spring (not shown). A torsion spring can be used as the biasing spring (not shown). The rack 27 is engaged with a screw portion 29a of a stepping motor 29. Therefore, the driving force of the stepping motor 29 is transmitted to the rack 27 via the screw portion 29a, and the second reference lens holding frame 22 moves in the optical axis direction. As a result, the second lens moving frame 20 including the second reference lens holding frame 22 can move in the optical axis direction between a first position closest to the image sensor 71a and a second position farthest from the image sensor 71a.

[0030] The aperture unit 24 is electrically connected to an aperture FPC 24b for inputting a current from the outside. The aperture FPC 24b is drawn from inside the lens barrel 1 to the outside of the rear fixed frame 81 and is connected to a lens FPC 88 connected to an external power source. The aperture unit 24 can freely change the size of the aperture diameter of the aperture 24a 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 24 is fixed to the second group reference lens holding frame 22 by two screws 26. The aperture FPC 24b is gradually refracted as the second group lens moving frame 20 including the second group reference lens holding frame 22 moves from a second position farthest from the image sensor 71a to a first position closest to the image sensor 71a.

[0031] 3(A) and 3(B) are perspective views showing the relationship between the third lens group moving frame 30 and the fourth lens group moving frame 40. Fig. 4 is a cross-sectional view of the sleeve 300 of the third lens group moving frame 30 and the sleeve 400 of the fourth lens group moving frame 40 at a common guide bar 84.

[0032] The third lens group moving frame 30 includes a sleeve 300 and a groove portion 303. The sleeve 300 is substantially C-shaped when viewed from a direction perpendicular to the optical axis, and includes two third group fitting portions (first fitting portions) that fit with the common guide bar 84 at positions spaced apart in the optical axis direction. The two third group fitting portions include a first third group fitting portion 301 and a second third group fitting portion 302. The first third group fitting portion 301 is located at the front end (front end portion) of the sleeve 300, and the second third group fitting portion 302 is located at the rear end (rear end portion) of the sleeve 300. The common guide bar 84 is inserted through the first third group fitting portion 301 and the second third group fitting portion 302. That is, the first third group fitting portion 301 and the second third group fitting portion 302 have circular holes that fit with the common guide bar 84. As a result, the third lens group moving frame 30 is supported so as to be movable in the optical axis direction. In this embodiment, the diameter of the hole formed in the first third group fitting portion 301 is larger than the diameter of the hole formed in the second third group fitting portion 302. The common guide bar 85 is inserted into the groove portion 303. As a result, the rotation of the third lens group moving frame 30 around the common guide bar 84 is restricted.

[0033] The rack 37 is fixed to the third lens group moving frame 30 in a state where it is biased in the optical axis direction and a direction perpendicular to the optical axis by a biasing spring (not shown). A torsion spring can be used as the biasing spring (not shown). The rack 37 is engaged with a screw portion 39a of a stepping motor 39. Therefore, the driving force of the stepping motor 39 is transmitted to the rack 37 via the screw portion 39a, and the third lens group moving frame 30 moves in the optical axis direction. This allows the third lens group moving frame 30 to move in the optical axis direction between a first position closest to the image sensor 71a and a second position farthest from the image sensor 71a.

[0034] The fourth lens group moving frame 40 includes a sleeve 400 and a groove 403. The sleeve 400 is substantially L-shaped when viewed from a direction perpendicular to the optical axis, and includes two fourth group fitting parts (second fitting parts) that fit into the common guide bar 84 at positions spaced apart in the optical axis direction. The two fourth group fitting parts are a first fourth group fitting part 401 and a second fourth group fitting part 402. The first fourth group fitting part 401 and the second fourth group fitting part 402 are included. The first fourth group fitting part 401 is located at the front end (front end) of the sleeve 400, and the second fourth group fitting part 402 is located at the rear end (rear end) of the sleeve 400. The common guide bar 84 is inserted through the first fourth group fitting part 401 and the second fourth group fitting part 402. That is, the first fourth group fitting portion 401 and the second fourth group fitting portion 402 have circular holes formed therein into which the common guide bar 84 fits. This allows the fourth group lens moving frame 40 to be supported so as to be movable in the optical axis direction. In this embodiment, the diameter of the hole formed in the first fourth group fitting portion 401 is larger than the diameter of the hole formed in the second fourth group fitting portion 402. The common guide bar 85 is inserted into the groove portion 403. This restricts the rotation of the fourth group lens moving frame 40 around the common guide bar 84.

[0035] The rack 47 is fixed to the fourth lens group moving frame 40 in a state where it is biased in the optical axis direction and a direction perpendicular to the optical axis by a biasing spring (not shown). A torsion spring can be used as the biasing spring (not shown). The rack 47 is engaged with a screw portion 49a of a stepping motor 49. Therefore, the driving force of the stepping motor 49 is transmitted to the rack 47 via the screw portion 49a, and the fourth lens group moving frame 40 moves in the optical axis direction. This allows the fourth lens group moving frame 40 to move in the optical axis direction between a first position closest to the image sensor 71a and a second position farthest from the image sensor 71a.

[0036] The sleeves 300 and 400 are arranged so that the approximately C-shaped and approximately L-shaped openings face each other. By arranging them in this way, the first fourth group fitting portion 401 is located between the first third group fitting portion 301 and the second third group fitting portion 302 in the optical axis direction. That is, the first fourth group fitting portion 401 is sandwiched between the first third group fitting portion 301 and the second third group fitting portion 302. Also, the second third group fitting portion 302 is located between the first fourth group fitting portion 401 and the second fourth group fitting portion 402 in the optical axis direction. That is, the second third group fitting portion 302 is sandwiched between the first fourth group fitting portion 401 and the second fourth group fitting portion 402.

[0037] With this configuration, the sleeves 300, 400 can be arranged to overlap in the optical axis direction. Therefore, the length of each of the sleeves 300, 400 in the optical axis direction can be increased without increasing the overall length of the lens barrel 1 in the optical axis direction, and the inclination of the third lens group moving frame 30 and the fourth lens group moving frame 40 relative to the optical axis can be reduced. In addition, by inserting the common guide bar 84 through the sleeves 300, 400, the relative inclination of the third lens group moving frame 30 and the fourth lens group moving frame 40 relative to the optical axis can be reduced compared to when each sleeve is supported by a different guide bar.

[0038] 1, the optical filter holding frame 60 holds an infrared cut filter 61 and a dummy glass 62, and is supported by a guide bar 86 so as to be movable in a direction perpendicular to the optical axis. The guide bar 87 engages with a groove in the optical filter holding frame 60, and restricts the rotation of the optical filter holding frame 60 around the guide bar 86.

[0039] The rack 67 is fixed to the optical filter holding frame 60 in a state where it is biased by a biasing spring (not shown) in a direction perpendicular to the optical axis and in a direction perpendicular to the perpendicular direction. A torsion spring can be used as the biasing spring (not shown). The rack 67 is engaged with a screw portion 69a of a stepping motor 69. Therefore, the driving force of the stepping motor 69 is transmitted to the rack 67 via the screw portion 69a, and the optical filter holding frame 60 moves in a direction perpendicular to the optical axis. This makes it possible to switch between the infrared cut filter 61 and the dummy glass 62 as optical filters on the optical path.

[0040] The following describes the state of the third lens group moving frame 30 and the fourth lens group moving frame 40 when assembled. FIG. 5 is a perspective view of the third lens group moving frame 30 and the fourth lens group moving frame 40 overlapping each other. FIG. 6 is a cross-sectional view of the third lens group moving frame 30 and the fourth lens group moving frame 40 overlapping each other in the optical axis. FIG. 7 is an explanatory diagram of the detailed shape of the third lens group moving frame 30. FIG. 7(A) is a view of the third lens group moving frame 30 seen from the fourth lens group moving frame 40 side, and FIG. 7(B) is a perspective view of the third lens group moving frame 30. FIG. 8 is an explanatory diagram of the detailed shape of the fourth lens group moving frame 40. FIG. 8(A) is a view of the fourth lens group moving frame 40 seen from the third lens group moving frame 30 side, and FIG. 8(B) is a perspective view of the fourth lens group moving frame 40. FIG. 9 is a view showing the state in which the first third group abutting portion 305a of the third lens group moving frame 30 and the first fourth group abutting portion 405a of the fourth lens group moving frame 40 come into contact with each other.

[0041] When assembling the lens barrel 1, the common guide bar 84 is inserted into the sleeves 300, 400 with the third lens group movement frame 30 and the fourth lens group movement frame 40 overlapped as shown in Fig. 5. At this time, the convex surface L3a, which is the rearmost lens surface of the third lens group L3, and the concave surface L4a, which is the frontmost lens surface of the fourth lens group L4, face each other and are close to each other as shown in Fig. 6. Therefore, if the relative positions of the third lens group movement frame 30 and the fourth lens group movement frame 40 are significantly misaligned, the convex surface L3a and the concave surface L4a may come into contact with each other and be damaged.

[0042] In this embodiment, the rearmost lens surface of the third lens group L3 is a convex surface, and the frontmost lens surface of the fourth lens group L4 is a concave surface, but the present invention is not limited to this. The rearmost lens surface of the third lens group L3 may be a concave surface, and the frontmost lens surface of the fourth lens group L4 may be a convex surface.

[0043] In this embodiment, in order to prevent contact between the convex surface L3a and the concave surface L4a, the third lens group moving frame 30 is provided with a third group guide portion (first engagement portion) 304 and a third group abutment portion (first contact portion) 305. Moreover, the fourth lens group moving frame 40 is provided with a fourth group guide portion (second engagement portion) 404 and a fourth group abutment portion (second contact portion) 405. Furthermore, the third lens group moving frame 30 is provided with a third group rotation stopper portion 306.

[0044] The third group guide section 304 is formed in an annular shape centered on the optical axis so as to cover the outer periphery of the convex surface L3a. Specifically, the shape of the third group guide section 304 is a wall shape formed so as to cover the outer periphery of the convex surface L3a. The annular shape includes not only a strictly annular shape but also a substantially annular shape (approximately annular shape). The fourth group guide section 404 includes a first fourth group guide section 404a, a second fourth group guide section 404b, a third fourth group guide section 404c, and a fourth fourth group guide section 404d, which are arranged on the outer periphery of the concave surface L4a along a circumferential direction centered on the optical axis. Specifically, the shape of each of the fourth group guide sections is a convex shape. The circumferential direction includes not only a strictly circumferential direction but also a substantially circumferential direction (approximately circumferential direction). In this embodiment, the third group guide section 304 is formed in an annular shape, but may be arranged along a circumferential direction centered on the optical axis.

[0045] The third group abutting portion 305 includes a first third group abutting portion 305a, a second third group abutting portion 305b, a third third group abutting portion 305c, and a fourth third group abutting portion 305d, each having a substantially oval shape extending in the circumferential direction. The first third group abutting portion 305a and the third third group abutting portion 305c are located on a line segment that passes near the optical axis and is substantially parallel to a line segment that connects the centers of the common guide bars 84 and 85, and on both sides of the convex surface L3a symmetrically about the optical axis. The second third group abutting portion 305b and the fourth third group abutting portion 305d are located on a line segment that passes near the optical axis and is substantially perpendicular to a line segment that connects the centers of the common guide bars 84 and 85, and on both sides of the convex surface L3a symmetrically about the optical axis.

[0046] The fourth group abutting portion 405 includes a first fourth group abutting portion 405a, a second fourth group abutting portion 405b, a third fourth group abutting portion 405c, and a fourth fourth group abutting portion 405d, each having a substantially oval shape extending in the radial direction. The first fourth group abutting portion 405a and the third fourth group abutting portion 405c are located on a line segment passing near the optical axis and substantially parallel to a line segment connecting the centers of the common guide bars 84 and 85, and on both sides of the concave surface L4a symmetrically about the optical axis. The second fourth group abutting portion 405b and the fourth fourth group abutting portion 405d are located on a line segment passing near the optical axis and substantially perpendicular to a line segment connecting the centers of the common guide bars 84 and 85, and on both sides of the concave surface L4a symmetrically about the optical axis.

[0047] When the third lens group movement frame 30 and the fourth lens group movement frame 40 are overlapped, the third lens group guide portion 304 and the fourth lens group movement frame 404 engage with each other with a play in the direction perpendicular to the optical axis direction (with a predetermined gap formed between them) as shown in Fig. 6. This makes it possible to regulate the relative positions of the third lens group movement frame 30 and the fourth lens group movement frame 40 in a plane perpendicular to the optical axis. Furthermore, when the lens barrel 1 is assembled, the third lens group movement frame 30 and the fourth lens group movement frame 40 can move in the optical axis direction along the common guide bars 84, 85 without interference between the third lens group guide portion 304 and the fourth lens group movement frame 40.

[0048] The third group rotation stopper 306 and the first fourth group guide portion 404a engage with some play when the third group lens movement frame 30 and the fourth group lens movement frame 40 are overlapped. This makes it possible to restrict relative rotation around the optical axis between the third group lens movement frame 30 and the fourth group lens movement frame 40. Furthermore, when the lens barrel 1 is in an assembled state, the third group lens movement frame 30 and the fourth group lens movement frame 40 can move in the optical axis direction along the common guide bars 84, 85 without interference between the third group rotation stopper 306 and the first fourth group guide portion 404a.

[0049] Furthermore, in a state where the third lens group moving frame 30 and the fourth lens group moving frame 40 are overlapped, the first to fourth third group abutting portions 305a-305d come into contact with the first to fourth fourth group abutting portions 405a-405d, respectively, within the range of the play described above. For example, as shown in FIG. 9, the first third group abutting portion 305a has a width larger than the play described above in the circumferential direction, and the first fourth group abutting portion 405a has a width larger than the play described above in the radial direction. Therefore, the first third group abutting portion 305a and the first fourth group abutting portion 405a can always abut against each other within the range of the play described above. With this configuration, the relative positions of the third lens group moving frame 30 and the fourth lens group moving frame 40 in the optical axis direction can be regulated.

[0050] The configuration described above makes it possible to regulate the relative positions of the third lens group movement frame 30 and the fourth lens group movement frame 40 in a state in which the third lens group movement frame 30 and the fourth lens group movement frame 40 are overlapped during assembly of the lens barrel 1. As a result, it is possible to prevent contact between the convex surface L3a and the concave surface L4a.

[0051] As described above, sleeves 300, 400 are supported by common guide bar 84, and grooves 303, 403 are supported by common guide bar 85. For this reason, when an impact is applied to lens barrel 1, third lens group movement frame 30 and fourth lens group movement frame 40 tend to bend in the direction of arrow A in a plane including the central axes of common guide bars 84, 85, as shown in Figures 7(B) and 8(B).

[0052] In this embodiment, as described above, the first third group abutting portion 305a and the third third group abutting portion 305c are located on a line segment that passes near the optical axis and is approximately parallel to a line segment that connects the centers of the common guide bars 84 and 85, and are located on both sides of the convex surface L3a symmetrically around the optical axis. Also, the first fourth group abutting portion 405a and the third fourth group abutting portion 405c are located on a line segment that passes near the optical axis and is approximately parallel to a line segment that connects the centers of the common guide bars 84 and 85, and are located on both sides of the concave surface L4a symmetrically around the optical axis. Therefore, when the third group lens moving frame 30 and the fourth group lens moving frame 40 are deflected in the direction of the arrow A, the first third group abutting portion 305a and the first fourth group abutting portion 405a, or the third third group abutting portion 305c and the third fourth group abutting portion 405c come into contact with each other. As a result, contact between the convex surface L3a and the concave surface L4a can be suppressed.

[0053] The first third group abutting portion 305a and the third third group abutting portion 305c have a shape extending in the circumferential direction, and the first fourth group abutting portion 405a and the third fourth group abutting portion 405c have a shape extending in the radial direction. Therefore, even if the third lens group movement frame 30 and the fourth lens group movement frame 40 are largely bent and the abutment positions of the corresponding abutting portions are shifted from their original positions by the amount of the bending, the above-mentioned abutting portions can abut reliably.

[0054] In addition, in this embodiment, as described above, the second third group abutting portion 305b and the fourth third group abutting portion 305d are located on a line segment that passes near the optical axis and is substantially perpendicular to a line segment that connects the centers of the common guide bars 84 and 85, and are located on both sides of the convex surface L3a symmetrically about the optical axis. Furthermore, the second fourth group abutting portion 405b and the fourth fourth group abutting portion 405d are located on a line segment that passes near the optical axis and is substantially perpendicular to a line segment that connects the centers of the common guide bars 84 and 85, and are located on both sides of the concave surface L4a symmetrically about the optical axis. Therefore, when a relative inclination occurs in the direction of the arrow B perpendicular to the direction of the arrow A between the third group lens movement frame 30 and the fourth group lens movement frame 40, the second third group and fourth group abutting portions 305b, 405b or the fourth third group and fourth group abutting portions 305d, 405d come into contact with each other. As a result, the relative inclination in the direction of the arrow B between the third lens group moving frame 30 and the fourth lens group moving frame 40 is restricted, making it possible to prevent contact between the convex surface L3a and the concave surface L4a.

[0055] The second third group abutting portion 305b and the fourth third group abutting portion 305d have a shape extending in the circumferential direction, and the second fourth group abutting portion 405b and the fourth fourth group abutting portion 405d have a shape extending in the radial direction. Therefore, even if the third group lens movement frame 30 and the fourth group lens movement frame 40 are largely bent and the abutment positions of the corresponding abutting portions are shifted from their original positions by the amount of the bending, the above-mentioned abutting portions can abut reliably.

[0056] The arrangement and shape of the abutment portion explained above makes it possible to prevent contact between adjacent lens surfaces even when the lens barrel 1 receives an impact or when the lens barrel 1 is assembled. EXAMPLES

[0057] Lens barrel 11 of this embodiment has a basically similar configuration to lens barrel 1 of embodiment 1, but the shapes of the third lens group, the third lens group movement frame, the fourth lens group, and the fourth lens group movement frame are different from those of lens barrel 1 of embodiment 1. In this embodiment, only the configuration that differs from embodiment 1 will be described.

[0058] The sleeves and grooves of the third lens group moving frame 130 and the fourth lens group moving frame 140 in this embodiment have the same shapes as the sleeve 300 and groove 303 of the third lens group moving frame 30 in Example 1, and the sleeve 400 and groove 403 of the fourth lens group moving frame 40 in Example 1, and are denoted by the same reference numerals.

[0059] The following describes the state of the third lens group movement frame 30 and the fourth lens group movement frame 40 when assembled. FIG. 10 is a perspective view of the third lens group movement frame 130 and the fourth lens group movement frame 140 overlapping each other. FIG. 11 is a cross-sectional view of the third lens group movement frame 130 and the fourth lens group movement frame 140 overlapping each other along the optical axis. FIG. 12 is an explanatory diagram of the detailed shape of the third lens group movement frame 130. FIG. 12(A) is a view of the third lens group movement frame 130 as seen from the fourth lens group movement frame 140 side, and FIG. 12(B) is a perspective view of the third lens group movement frame 130. FIG. 13 is an explanatory diagram of the detailed shape of the fourth lens group movement frame 140. FIG. 13(A) is a view of the fourth lens group movement frame 140 as seen from the third lens group movement frame 130 side, and FIG. 13(B) is a perspective view of the fourth lens group movement frame 140. FIG. 14 is a diagram showing a state in which the first third group abutting portion 1305a of the third lens group moving frame 130 and the fourth group abutting portion 1405 of the fourth lens group moving frame 140 come into contact with each other.

[0060] When assembling the lens barrel 11, the common guide bar 84 is inserted into the sleeves 300, 400 with the third lens group movement frame 130 and the fourth lens group movement frame 140 overlapping as shown in Fig. 10. At this time, the convex surface L30a, which is the rearmost lens surface of the third lens group L30, and the concave surface L40a, which is the frontmost lens surface of the fourth lens group L40, face each other and are close to each other as shown in Fig. 11. Therefore, if the relative positions of the third lens group movement frame 130 and the fourth lens group movement frame 140 are significantly misaligned, the convex surface L30a and the concave surface L40a may come into contact with each other and be damaged.

[0061] In this embodiment, the rearmost lens surface of the third lens group L30 is a convex surface, and the frontmost lens surface of the fourth lens group L40 is a concave surface, but the present invention is not limited to this. The rearmost lens surface of the third lens group L30 may be a concave surface, and the frontmost lens surface of the fourth lens group L40 may be a convex surface.

[0062] In this embodiment, in order to suppress contact between the convex surface L3a and the concave surface L4a, the third lens group moving frame 230 is provided with a third group guide portion (first engagement portion) 1304 and a third group abutment portion (first abutment portion) 1305. Moreover, the fourth lens group moving frame 140 is provided with a fourth group guide portion (second engagement portion) 1404 and a fourth group abutment portion (second abutment portion) 1405. In this embodiment, the top surface of the fourth group guide portion 1404 functions as the fourth group abutment portion 1405.

[0063] The third group guide section 1304 is formed in a circular ring shape centered on the optical axis so as to cover the outer periphery of the convex surface L30a. Specifically, the shape of the third group guide section 1304 is a wall shape formed so as to cover the outer periphery of the convex surface L30a. The fourth group guide section 1404 is formed in a circular ring shape centered on the optical axis so as to cover the outer periphery of the concave surface L40a. Specifically, the shape of the fourth group guide section 1404 is a wall shape formed so as to cover the outer periphery of the concave surface L40a. Note that the circular ring shape includes not only the case where it is strictly circular, but also the case where it is substantially circular (approximately circular).

[0064] The third group abutting portion 1305 includes a first third group abutting portion 1305a, a second third group abutting portion 1305b, a third third group abutting portion 1305c, and a fourth third group abutting portion 1305d, each having a rib shape extending in the radial direction. The first third group abutting portion 1305a and the third third group abutting portion 1305c pass near the optical axis, are located on a line segment that is approximately parallel to a line segment that connects the centers of the common guide bars 84 and 85, and are located on both sides of the convex surface L30a symmetrically about the optical axis. The second third group abutting portion 1305b and the fourth third group abutting portion 1305d pass near the optical axis, are located on a line segment that is approximately perpendicular to a line segment that connects the centers of the common guide bars 84 and 85, and are located on both sides of the convex surface L30a symmetrically about the optical axis.

[0065] The fourth group abutment portion 1405 is the top surface of the fourth group guide portion 1404, and is formed in a substantially circular ring shape centered on the optical axis.

[0066] The third group guide portion 1304 and the fourth group guide portion 1404 engage with each other with a play (with a predetermined gap formed between them) when the third group lens movement frame 130 and the fourth group lens movement frame 140 are overlapped, as shown in FIG. 11. This allows the relative positions of the third group lens movement frame 130 and the fourth group lens movement frame 140 to be regulated in a plane perpendicular to the optical axis. In addition, when the lens barrel 1 is assembled, the third group lens movement frame 130 and the fourth group lens movement frame 140 can move in the optical axis direction along the common guide bars 84 and 85 without interference between the third group guide portion 1304 and the fourth group guide portion 1404. As shown in FIG. 11, chamfered portions 1304a and 1404a are formed on the portions of the third group guide portion 1304 and the fourth group guide portion 1404 that face each other when they are engaged with each other. This makes it easier to engage the third group guide portion 1304 and the fourth group guide portion 1404 when the third group lens moving frame 130 and the fourth group lens moving frame 140 are overlapped.

[0067] Furthermore, in a state where the third lens group moving frame 130 and the fourth lens group moving frame 140 are overlapped, the first to fourth third group abutting portions 1305a-1305d abut against the fourth group abutting portion 1405 within the range of the play described above. For example, as shown in FIG. 14, the first third group abutting portion 1305a has a width in the radial direction larger than the play described above, and the fourth group abutting portion 1405a is formed in a substantially annular shape centered on the optical axis. Therefore, the first third group abutting portion 1305a and the fourth group abutting portion 1405a can always abut against each other within the range of the play described above. This allows the relative positions of the third lens group moving frame 130 and the fourth lens group moving frame 140 in the optical axis direction to be regulated.

[0068] The configuration described above makes it possible to regulate the relative positions of the third lens group movement frame 130 and the fourth lens group movement frame 140 in a state in which the third lens group movement frame 130 and the fourth lens group movement frame 140 are overlapped during assembly of the lens barrel 1. As a result, contact between the convex surface L30a and the concave surface L40a can be suppressed.

[0069] As described above, sleeves 300, 400 are supported by common guide bar 84, and grooves 303, 403 are supported by common guide bar 85. For this reason, when an impact is applied to lens barrel 1, third lens group movement frame 130 and fourth lens group movement frame 140 tend to bend in the direction of arrow A in a plane including the central axes of common guide bars 84, 85, as shown in Figures 12(B) and 13(B).

[0070] In this embodiment, as described above, the first third group abutting portion 1305 and the third third group abutting portion 1305c are located on a line segment that passes near the optical axis and is approximately parallel to a line segment that connects the centers of the common guide bars 84 and 85, and are located on both sides of the convex surface L30a symmetrically about the optical axis. In addition, the fourth group abutting portion 1405 is formed in an approximately annular shape centered on the optical axis. Therefore, when the third group lens moving frame 130 and the fourth group lens moving frame 140 are deflected in the direction of the arrow A, the first third group abutting portion 1305a and the fourth group abutting portion 1405, or the third third group abutting portion 1305c and the fourth group abutting portion 1405 come into contact with each other. As a result, contact between the convex surface L30a and the concave surface L40a can be suppressed.

[0071] The first third group abutting portion 1305a and the third third group abutting portion 1305c have a shape extending in the radial direction, and the fourth group abutting portion 1405 is formed in a substantially circular ring shape centered on the optical axis. Therefore, even if the third group lens movement frame 130 and the fourth group lens movement frame 140 are largely bent and the abutment positions of the corresponding abutting portions are shifted from their original positions by the amount of the bending, the above-mentioned abutting portions can abut reliably.

[0072] In addition, in this embodiment, as described above, the second third group abutting portion 1305b and the fourth third group abutting portion 1305d are located on a line segment that passes near the optical axis and is substantially perpendicular to a line segment that connects the centers of the common guide bars 84 and 85, and are located on both sides of the convex surface L30a symmetrically about the optical axis. Furthermore, the fourth group abutting portion 1405 is formed in a substantially annular shape centered on the optical axis. Therefore, when a relative tilt occurs in the direction of the arrow B perpendicular to the direction of the arrow A between the third group lens movement frame 130 and the fourth group lens movement frame 140, the second third group abutting portion 1305b and the fourth group abutting portion 1405 come into contact with each other. Or the fourth third group abutting portion 1305d and the fourth group abutting portion 1405 come into contact with each other. As a result, the relative inclination in the direction of the arrow B between the third lens group moving frame 130 and the fourth lens group moving frame 140 is restricted, and contact between the convex surface L30a and the concave surface L40a can be suppressed. The second third group abutting portion 1305b and the fourth third group abutting portion 1305d have a shape extending in the radial direction, and the fourth group abutting portion 1405 is formed in a substantially annular shape centered on the optical axis. Therefore, even if the third group lens movement frame 130 and the fourth group lens movement frame 140 are largely bent and the abutment positions of the corresponding abutting portions are shifted from their original positions by the amount of the bending, the above-mentioned abutting portions can abut reliably.

[0073] The arrangement and shape of the abutment portions described above make it possible to prevent contact between adjacent lens surfaces when lens barrel 11 is subjected to an impact or when lens barrel 11 is assembled.

[0074] In this embodiment, the curvature of the convex surface L30a is greater than the curvature of the concave surface L40a. Compared to a case in which the curvature of the convex surface L30a is smaller than the curvature of the concave surface L40a, the lens spacing between the third lens group L30 and the fourth lens group L40 can be made closer, and the overall length of the lens barrel 11 in the optical axis direction can be shortened.

[0075] With the configuration described above, in a lens barrel in which the fitting portions of the sleeves of two lens frames are alternately arranged on one guide bar, it is possible to improve the ease of assembly and yield without increasing the size, while also increasing impact resistance.

[0076] The disclosure of this embodiment includes the following configuration. (Configuration 1) a first holding member that holds the first lens; a second holding member that holds a second lens disposed adjacent to the first lens in the optical axis direction; a first guide bar that supports the first and second holding members movably in the optical axis direction; a second guide bar that restricts rotation of the first and second holding members around the first guide bar, the first holding member includes two first engagement portions that engage with the first guide bar at positions spaced apart in the optical axis direction and a first groove portion that engages with the second guide bar, the second holding member includes two second engagement portions that engage with the first guide bar at positions spaced apart in the optical axis direction, and a second groove portion that engages with the second guide bar; One of the first mating portions is located between the second mating portions in the optical axis direction, one of the second mating portions is located between the first mating portions in the optical axis direction, the first holding member includes a first engagement portion and a first abutment portion; the second holding member includes a second engagement portion and a second abutment portion; the first and second engagement portions are engaged with each other in a direction perpendicular to the optical axis direction with a gap therebetween, a first engagement portion that engages with a second engagement portion of the first lens and a second engagement portion that engages with the first lens; (Configuration 2) The lens barrel described in configuration 1, characterized in that the first engagement portion and the second engagement portion are each arranged along a circumferential direction centered on the optical axis, or formed in a ring shape centered on the optical axis. (Configuration 3) the first engagement portion has a wall shape formed to cover an outer periphery of the first lens, The lens barrel according to configuration 1 or 2, wherein the second engagement portion includes at least one convex shape, or has a wall shape formed so as to cover the outer periphery of the second lens. (Configuration 4) The lens barrel according to any one of configurations 1 to 3, wherein a chamfer is formed on each of the first and second engagement portions at portions that face each other when engaged with each other. (Configuration 5) The first contact portion has a shape extending in a radial direction, The lens barrel according to any one of configurations 1 to 4, wherein the second contact portion has a shape extending in a circumferential direction. (Configuration 6) The lens barrel described in any one of configurations 1 to 5, characterized in that the first and second abutment portions are respectively provided on both sides of the first and second holding members, on a line segment that passes through the optical axis and is parallel to a line segment connecting the centers of the first and second guide bars, and symmetrically about the optical axis. (Configuration 7) The lens barrel described in configuration 6, characterized in that the first and second abutment portions are respectively provided on both sides of the first and second holding members, on a line segment that passes through the optical axis and is perpendicular to a line segment connecting the centers of the first and second guide bars, and symmetrically about the optical axis. (Configuration 8) one of the opposing lens surfaces of the first and second lenses is a convex surface; The lens barrel according to any one of configurations 1 to 7, wherein the other of the opposing lens surfaces of the first and second lenses is a concave surface. (Configuration 9) The lens barrel of configuration 8, wherein the curvature of the convex surface is greater than the curvature of the concave surface.

[0077] 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]

[0078] 1, 11 Lens barrel 30, 130 3rd lens group moving frame (first holding member or second holding member) 301 First third group fitting portion (first fitting portion or second fitting portion) 302 second 3-group fitting portion (first fitting portion or second fitting portion) 303 Groove (first groove or second groove) 304, 1304 3rd group guide portion (first engagement portion or second engagement portion) 305, 1305 3rd group abutment part (first abutment part or second abutment part) 40, 140 4th lens group moving frame (second holding member or first holding member) 401 First 4th group fitting portion (second fitting portion or first fitting portion) 402 Second 4th group fitting portion (second fitting portion or first fitting portion) 403 Groove (second groove or first groove) 404, 1404 4th group guide portion (second engagement portion or first engagement portion) 405, 1405 4th group abutment part (second abutment part or first abutment part) 84 Common guide bar (first guide bar) 85 Common guide bar (second guide bar)

Claims

1. a first holding member that holds a first lens; a second holding member that holds a second lens disposed adjacent to the first lens in the optical axis direction; a first guide bar that supports the first and second holding members movably in the optical axis direction; a second guide bar that restricts rotation of the first and second holding members around the first guide bar, the first holding member includes two first engagement portions that engage with the first guide bar at positions spaced apart in the optical axis direction and a first groove portion that engages with the second guide bar, the second holding member includes two second engagement portions that engage with the first guide bar at positions spaced apart in the optical axis direction, and a second groove portion that engages with the second guide bar; one of the first mating portions is located between the second mating portions in the optical axis direction, One of the second mating portions is located between the first mating portions in the optical axis direction, the first holding member includes a first engagement portion and a first abutment portion; the second holding member includes a second engaging portion and a second abutting portion; the first and second engagement portions are engaged with each other in a direction perpendicular to the optical axis direction with a gap therebetween, a first engagement portion that engages with a second engagement portion of the first lens and a second engagement portion that engages with the first lens;

2. 2. The lens barrel according to claim 1, wherein the first engagement portion and the second engagement portion are each arranged along a circumferential direction centered on the optical axis, or formed in an annular shape centered on the optical axis.

3. the first engagement portion has a wall shape formed to cover an outer periphery of the first lens, 3. The lens barrel according to claim 1, wherein the second engagement portion includes at least one convex shape, or has a wall shape formed so as to cover an outer periphery of the second lens.

4. 3. The lens barrel according to claim 1, wherein chamfers are formed on the portions of the first and second engagement portions that face each other when they are engaged with each other.

5. The first contact portion has a shape extending in a radial direction, 3. The lens barrel according to claim 1, wherein the second contact portion has a shape extending in a circumferential direction.

6. The lens barrel according to claim 1 or 2, characterized in that the first and second abutment portions are provided on both sides of the first and second holding members, respectively, on a line segment that passes through the optical axis and is parallel to a line segment connecting the centers of the first and second guide bars, and symmetrically about the optical axis.

7. The lens barrel according to claim 6, characterized in that the first and second abutment portions are provided on both sides of the first and second holding members, respectively, on a line segment that passes through the optical axis and is perpendicular to a line segment connecting the centers of the first and second guide bars, and symmetrically about the optical axis.

8. one of the opposing lens surfaces of the first and second lenses is a convex surface; 3. The lens barrel according to claim 1, wherein the other of the opposing lens surfaces of the first and second lenses is a concave surface.

9. 9. The lens barrel according to claim 8, wherein the curvature of the convex surface is greater than the curvature of the concave surface.

Images