JP2020046462A - Zoom lens barrel - Google Patents

Abstract

To provide a zoom lens barrel that can maintain a smooth zooming action without increase in the number of components even when impacts occur due to falling and the like.SOLUTION: In a zoom lens barrel in which a sliding barrel 12 has a cam follower 12A protruding on one side in a radial direction, and a rectilinear-shuttle stud 12B protruding on other side in the radial direction, a cam groove 8A into which a cam follower 12A is caught is formed in a second rotary barrel 8, a vertical groove 14B into which the rectilinear-shuttle bud 12A is caught is formed in an outer barrel 14, and the sliding barrel 12 is extended in an optical axis direction by the second rotary barrel 8 being rotated with respect to the outer barrel 14, the rectilinear-shuttle stud 12B has a nut 74 that protrudes on the other side in the radial direction of the sliding barrel 12, and in addition to the cam groove 8A, an auxiliary cam groove 8C is formed in the second rotary barrel 8, and the nut 74 of the rectilinear-shuttle stud 12B is caught into the auxiliary cam groove 8C.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a zoom lens barrel.

  Conventionally, as a zooming mechanism in a zoom lens barrel, a first barrel in which a cam follower is provided upright, and a second barrel in which a cam groove is formed, the cam follower is engaged with the cam groove, There is known a configuration in which a first lens barrel is rotated with respect to a second lens barrel to advance and retract the first lens barrel.

  If such a zoom lens barrel is accidentally dropped, the cam follower may fall out of the cam groove, or the cam follower may collide with the edge of the cam groove and cause damage to the peripheral edge of the cam groove. I do. If the cam groove is deformed, a smooth zooming operation cannot be performed.

  On the other hand, Patent Document 1 discloses that a cam pin and a drop-out prevention pin having the same shape provided on a drive frame are engaged with a cam groove and a drop-out prevention groove provided on a cam frame, respectively. There is disclosed a configuration for preventing the falling off from the cam groove.

JP 2005-128188 A

  However, in the configuration described in Patent Literature 1, it is necessary to newly add a drop-out prevention pin, and the number of components increases.

  The present invention has been made in view of the above problems, and provides a zoom lens barrel that can maintain a smooth zooming operation without an increase in the number of parts and even when an impact occurs due to a drop or the like. The purpose is to:

  The zoom lens barrel of the present invention includes a sliding barrel, a rotating barrel provided on one side in the radial direction of the sliding barrel, and a tubular member provided on the other side in the radial direction of the sliding barrel. The sliding cylinder has a first top member protruding to one side in the radial direction and a second top member protruding to the other side in the radial direction, and a cam into which the first top member enters the rotary cylinder. A groove is formed, and a groove into which the second frame member is inserted is formed in the cylindrical member, and when the rotating cylinder is rotated with respect to the cylindrical member, the sliding cylinder is extended in the optical axis direction. A lens barrel, wherein the sliding barrel has a protrusion protruding on the other side in the radial direction of the second top member, and the rotating barrel has an auxiliary cam groove in addition to the cam groove; The protrusion of the second top member is inserted into the auxiliary cam groove.

  According to the present invention having the above configuration, even when an impact is applied to the sliding cylinder, the projecting portion of the second top member collides with the edge of the auxiliary cam groove, and the first top member collides with the cam groove. It is possible to reduce or eliminate the impact when performing. Thereby, the first frame member or the cam groove can be prevented from being damaged, and a smooth zooming operation can be maintained. Further, since the projecting portion of the second frame member is used, it is not necessary to provide a new member, and an increase in the number of members can be prevented.

In the present invention, preferably, the auxiliary cam groove has a shape having the same locus as the cam groove.
According to the present invention having the above-described configuration, smooth zooming can be maintained, and a space for forming the auxiliary cam groove can be easily secured.

  Preferably, in the present invention, the first top member has a roller made of an elastic material, and the roller enters the cam groove, and the diameter of the roller is substantially equal to the width of the cam groove.

  According to the present invention having the above configuration, the roller of the first top member elastically deforms even when an impact is applied to the sliding cylinder. This can more reliably prevent the first top member or the cam groove from being damaged.

  Preferably, in the present invention, the protruding portion of the second top member enters the auxiliary cam groove with a gap formed between the protrusion and the side surface of the auxiliary cam groove.

  According to the present invention having the above configuration, at the time of zooming, the sliding cylinder is guided by the first frame member and the cam groove, so that a smooth zooming operation can be maintained. Then, when an impact is applied to the sliding cylinder and the roller of the first frame member is elastically deformed, the roller comes into contact with the side of the auxiliary cam groove of the second frame member, and the first frame member or the cam groove is damaged. Can be prevented.

In the present invention, preferably, the material of the protruding portion is harder than the material of the roller.
According to the present invention having the above-described structure, when the second top member abuts against the side of the auxiliary cam groove when an impact is applied, the impact acting on the roller is extremely small, thereby preventing the roller from being damaged. be able to.

  According to the present invention, it is possible to provide a zoom lens barrel that can maintain a smooth zooming operation without an increase in the number of components and even when an impact occurs due to a drop or the like.

FIG. 2 is a longitudinal sectional view along the optical axis showing the zoom lens barrel according to the first embodiment, showing a wide angle state. FIG. 2 is a longitudinal sectional view along the optical axis showing the zoom lens barrel according to the first embodiment, and FIG. 2 shows a telephoto state. FIG. 2 is a perspective view showing an inner fixed barrel and a first rotary barrel of the zoom lens barrel shown in FIG. 1. FIG. 2 is a perspective view showing a sliding barrel, an outer barrel, a second rotating barrel, and a fixed barrel in the zoom lens barrel shown in FIG. 1. FIG. 2 is an enlarged sectional view showing a cam follower of a sliding barrel of the zoom lens barrel shown in FIG. 1. FIG. 2 is an enlarged cross-sectional view illustrating a rectilinear top of a sliding barrel of the zoom lens barrel illustrated in FIG. 1.

Hereinafter, an embodiment of a zoom lens barrel according to the present invention will be described in detail with reference to the drawings.
1 and 2 are longitudinal sectional views along the optical axis showing the zoom lens barrel according to the first embodiment. FIG. 1 shows a wide-angle state, and FIG. 2 shows a telephoto state.
As shown in FIGS. 1 and 2, the lens barrel 1 of the present embodiment includes a first lens group A, a second lens group B, a third lens group C, a fourth lens group D, and a fifth lens group E. Prepare. The fourth lens group D includes a shift lens group that is shifted in a direction orthogonal to the optical axis to prevent camera shake.

  The zoom lens barrel 1 includes a mount 2 attached to a camera body, an outer fixed barrel 4 and an inner fixed barrel 6 integrated with the mount 2, and a first rotary barrel 10 disposed inside the inner fixed barrel 6. Having. The outer fixed barrel 4 is configured by connecting a rear outer fixed barrel 4A on the imaging side and a front outer fixed barrel 4B on the subject side. A zoom operation ring 22 is rotatably arranged on the outer periphery of the front outer fixed cylinder 4B. A focus operation ring 20 is rotatably arranged on the outer periphery of the rear outer fixed cylinder 4A.

  FIG. 3 is a perspective view showing an inner fixed barrel and a first rotary barrel of the zoom lens barrel shown in FIG. As shown in the figure, the inner fixed cylinder 6 is formed by connecting a front cylindrical portion 6A on the subject side and a rear cylindrical portion 6B on the image forming side. The front cylindrical portion 6A has a larger diameter than the rear cylindrical portion 6B, and the front cylindrical portion 6A and the rear cylindrical portion 6B are connected in a stepped manner. The first rotary cylinder 10 is formed by connecting a front cylindrical portion 10A on the subject side, a rear cylindrical portion 10C on the imaging side, and an intermediate cylindrical portion 10B between the front cylindrical portion 10A and the rear cylindrical portion 10C. . The front cylindrical portion 10A has a larger diameter than the intermediate cylindrical portion 10B, the front cylindrical portion 10A and the intermediate cylindrical portion 10B are connected in a stepped manner, and the intermediate cylindrical portion 10B has a larger diameter than the rear cylindrical portion 10C. The portion 10B and the rear cylindrical portion 10C are connected in a stepped manner.

  As shown in FIGS. 1 and 2, a second rotating cylinder 8 is arranged outside the inner fixed cylinder 6, and a sliding cylinder 12 is arranged outside the second rotating cylinder 8. An outer tube (cylinder member) 14 is arranged outside the sliding tube 12 and inside the front outer fixed tube 4B. The first rotating cylinder 10 and the second rotating cylinder 8 are connected at the distal end, and the first rotating cylinder 10 and the second rotating cylinder 8 move forward and backward while rotating in conjunction with each other.

FIG. 4 is a perspective view showing a sliding barrel, an outer barrel, a second rotating barrel, and a fixed barrel in the zoom lens barrel shown in FIG.
A cam follower 8D is provided upright on the inner surface of the second rotary cylinder 8 at the image-forming end. Further, a cam groove 6a is formed in the front cylindrical portion 6A of the inner fixed cylinder 6 so as to be inclined in a predetermined direction in the circumferential direction toward the subject side. The cam follower 8D of the second rotary cylinder 8 is fitted (engaged) in the cam groove 6a of the inner fixed cylinder 6. Thus, when the zoom operation ring 22 is rotated, the first rotary cylinder 10 and the second rotary cylinder 8 rotate relative to the inner fixed cylinder 6 in conjunction with the zoom operation ring 22, and advance and retreat in the optical axis direction. .

  The outer cylinder 14 has a rectilinear top 14A formed on the outer surface at the rear end. The rectilinear top 14A is fitted in a vertical groove formed in the inner surface of the front outer fixed cylinder 4B of the outer fixed cylinder 4 and extending in the optical axis direction. It is crowded. Thus, the rotation of the outer cylinder 14 is restrained, and the outer cylinder 14 can move forward and backward.

  The sliding barrel 12 has a rectilinear top (second top member) 12A formed on the outer surface at the rear end. The rectilinear top 12A is formed in a vertical groove 14B formed on the inner surface of the outer cylinder 14 and extending in the optical axis direction. I'm stuck. Accordingly, the rotation of the sliding cylinder 12 is restricted, and the sliding cylinder 12 can move forward and backward with respect to the outer cylinder 14.

  A cam groove 8A is formed on the outer surface of the second rotary cylinder 8 so as to extend obliquely in a predetermined circumferential direction toward the subject side. A cam follower (first top member) 12B provided upright on the inner surface of the rear end of the sliding cylinder 12 is fitted into the cam groove 8A. A lateral groove 8B extending in the circumferential direction is formed at the rear end of the second rotary cylinder 8. A top 14C standing upright on the inner surface of the rear end of the outer cylinder 14 is fitted into the lateral groove 8B. Further, an auxiliary cam groove 8C having the same shape as the cam groove 8A, that is, a shape having the same locus is formed between the circumferentially adjacent cam grooves 8A. The cam grooves 8A and the auxiliary cam grooves 8C are provided at equal intervals in the circumferential direction.

  FIG. 5 is an enlarged sectional view showing a cam follower of the sliding barrel of the zoom lens barrel shown in FIG. FIG. 6 is an enlarged cross-sectional view showing a straight-moving coma of the sliding barrel of the zoom lens barrel shown in FIG. As shown in FIG. 5, the cam follower 12B of the sliding cylinder 12 includes a screw 60, a cam follower shaft 62, and a roller 64. The cam follower shaft 62 is disk-shaped, and has a through hole 62A formed at the center. In the cam follower 12B, the cam follower shaft 62 is disposed at a position corresponding to the through hole 12C on the inner surface of the sliding cylinder 12, the screw 60 is inserted through the through hole 12C from outside the sliding cylinder 12, and the tip of the screw 60 is connected to the cam follower shaft 62. Is attached to the sliding cylinder 12 by being screwed into the through hole 62A. The tip portion 62B of the cam follower shaft 62 has a smaller diameter than other portions, and a roller 64 is rotatably attached to the tip portion 62B. The roller 64 is formed of an elastically deformable material such as rubber, for example. In the mounted state of the cam follower 12B, the head of the screw 60 does not protrude from the outer surface of the sliding cylinder 12, and the cam follower shaft 62 and the roller 64 protrude from the inner surface. The outer diameter of the roller 64 of the cam follower 12B is substantially equal to the width of the cam groove 8A of the second rotary cylinder 8. The cam follower 12B is engaged with the cam groove 8A with the roller 64 in contact with the inner surface of the cam groove 8A.

  As shown in FIG. 6, the rectilinear top 12A of the sliding cylinder 12 includes a screw 70, a top member 72, and a nut member 74. The top member 72 is disk-shaped, and has a through hole 72A formed at the center. The straight top 12A has the top member 72 disposed at a position corresponding to the through hole 12D on the outer surface of the sliding cylinder 12, and allows the screw 70 to pass through the through hole 72A of the top member 72 and the through hole 12D of the sliding cylinder 12. The screw 70 is attached to the sliding cylinder 12 by tightening a nut 74 to the distal end. In a state in which the rectilinear top 12A is attached to the sliding cylinder 12, the top member 72 projects from the outer surface of the sliding cylinder 12, and the nut 74 projects from the inner surface of the sliding cylinder. The top member 72 enters the vertical groove 14B of the outer cylinder 14, and the nut 74 enters the auxiliary cam groove 8C of the second rotary cylinder 8. The nut 74 is circular, the diameter of the nut 74 is slightly smaller than the width of the auxiliary cam groove 8C, and a gap is provided between the nut 74 and the side surface of the auxiliary cam groove 8C. The nut 74 of the rectilinear piece 12A is preferably formed of a material harder than the roller 64 of the cam follower 12B, such as metal such as brass or stainless steel. The gap between the nut 74 and the auxiliary cam 8C is smaller than the thickness of the roller 64 in the radial direction.

  The rectilinear top 12A and the cam follower 12B are provided on the sliding cylinder 12 at equal intervals in the circumferential direction. When the cam follower 12B moves along the cam groove 8A of the sliding cylinder 12, the nut 74 moves in the auxiliary cam groove 8C. In the present embodiment, the cam groove 8A and the auxiliary cam groove 8C have the same shape. However, the present invention is not limited to this. For example, if the outer diameter of the nut 74 that enters the auxiliary cam groove 8C is large, The auxiliary cam groove 8C corresponds to the cam groove 8A so that the nut 74 can move in the auxiliary cam groove 8C when the cam follower 12B moves along the cam groove 8A. Any shape is acceptable.

  With such a configuration, when the second rotary cylinder 8 rotates in conjunction with the first rotary cylinder 10, the second rotary cylinder 8 moves in the optical axis direction together with the outer cylinder 14, and further, the sliding cylinder 12 It advances and retracts in the optical axis direction with respect to the rotating cylinder 8.

  As shown in FIGS. 1 and 2, the first lens group A is held by being surrounded by a first lens frame 30. The first lens frame 30 is attached inside the distal end of the sliding cylinder 12. As described above, when the first rotary cylinder 10 is rotated with respect to the inner fixed cylinder 6, the second rotary cylinder 8 advances and retreats in the optical axis direction, and the sliding cylinder 12 advances and retreats with respect to the second rotary cylinder 8. I do.

  The second lens group B is held by being surrounded by the second lens frame 32. A top 32A is provided upright on the outer peripheral surface of the second lens frame 32. The top 32 </ b> A enters the vertical groove 10 a formed in the first rotary cylinder 10 and the cam groove 6 c of the inner fixed cylinder 6. Accordingly, when the first rotary barrel 10 advances and retreats while rotating with respect to the inner fixed barrel 6, the second lens frame 32 rotates in conjunction with the first rotary barrel 10 and rotates with respect to the first rotary barrel 10. Retreat.

  The third lens group C is held by being surrounded by the third lens frame 34. A top 34A is provided upright on the outer peripheral surface of the third lens frame 34. The top 34A enters a cam groove 10b formed in the first rotary cylinder 10. The rotation of the third lens group C is restricted by a guide member (not shown) extending from the fourth lens group D. Accordingly, the third lens frame 34 is configured to advance and retreat with respect to the first rotary cylinder 10 without rotating when the first rotary cylinder 10 advances and retracts while rotating with respect to the inner fixed cylinder 6. .

  The fourth lens group D is held by being surrounded by the fourth lens frame 36. A top 36A is provided upright on the outer peripheral surface of the fourth lens frame 36. The top 36 </ b> A enters a lateral groove 10 c formed in the first rotating cylinder 10 and a vertical groove (not shown) formed on the inner surface of the inner fixed cylinder 6. Thus, when the first rotary cylinder 10 advances and retreats while rotating with respect to the inner fixed cylinder 6, the fourth lens frame 36 advances and retreats together with the first rotary cylinder 10 without rotating.

  The fifth lens group is surrounded and held by a fifth lens frame 38. A top 38A is provided upright on the outer peripheral surface of the fifth lens frame 38. The top 38A enters a cam groove 10d formed in the first rotary cylinder 10 and a vertical groove (not shown) formed in the fourth lens frame 36. Thus, the fifth lens frame 38 is configured to advance and retreat with respect to the first rotary cylinder 10 without rotating when the first rotary cylinder 10 is rotated with respect to the inner fixed cylinder 6.

  Further, the zoom lens barrel 1 includes a diaphragm mechanism 40 disposed between the second lens group B and the third lens group C.

Hereinafter, a zooming operation in the zoom lens barrel according to the present embodiment will be described.
The zoom lens barrel 1 is used with a mount 2 attached to a camera body. By attaching the mount 2 to the camera body, the outer fixed barrel 4 and the inner fixed barrel 6 are fixed to the camera body. The zoom operation can be performed by rotating the zoom operation ring 22. When the zoom operation ring 22 is rotated, the first rotary cylinder 10 and the second rotary cylinder 8 rotate in conjunction with the rotation.

  When the first rotary cylinder 10 is rotated with respect to the inner fixed cylinder 6, the first rotary cylinder 10 moves in the optical axis direction. When the first rotary cylinder 10 is rotated with respect to the inner fixed cylinder 6, the second, third, fourth, and fifth lens frames 32, 34, 36, and 38 move in the optical axis direction, respectively.

Further, when the second rotary cylinder 8 rotates, the second rotary cylinder 8 moves in the optical axis direction together with the outer cylinder 14, and further, the sliding cylinder 12 advances and retreats with respect to the second rotary cylinder 8 in the optical axis direction. Thereby, the first lens frame 30 moves in the optical axis direction.
Thereby, each lens group moves in the optical axis direction, and zooming is performed.

  Here, when the zoom lens barrel 1 falls with the zoom lens barrel 1 attached to the camera and the sliding cylinder 12 collides with the ground, an impact is applied to the sliding cylinder 12. When an impact is applied to the sliding cylinder 12, first, since the roller 64 of the cam follower 12B is in contact with the cam groove 8A of the second rotating cylinder 8, the roller 64 is sandwiched between the side surface of the cam groove 8A and the cam follower shaft 62. The part is compressed. When a part of the roller 64 is compressed in this manner, the side portion of the nut 74 of the straight advance piece 12A comes into contact with the side surface of the auxiliary cam groove 8C. For this reason, it is possible to prevent an excessive force from acting on the cam follower 12B and the cam groove 8A without further compressing and deforming the roller 64. Thereby, breakage of the cam follower 12B and the cam groove 8A can be prevented.

As described above, according to the present embodiment, the following effects can be obtained.
According to this embodiment, even when an impact is applied to the sliding cylinder 12, the nut 74 of the rectilinear top 12A hits the edge of the auxiliary cam groove 8C, and the impact when the cam follower 12B collides with the cam groove 8A. Can be eliminated. Thereby, it is possible to prevent the cam follower 12B or the cam groove 8A from being damaged, and to maintain a smooth zooming operation. Further, since the nut 74 of the straight advance piece 12A is used, it is not necessary to provide a new member, and it is possible to prevent an increase in the number of members.

  In the present embodiment, the auxiliary cam groove 8C has a shape having the same trajectory as the cam groove 8A. Thereby, smooth zooming can be maintained, and a space for forming the auxiliary cam groove 8C can be easily secured.

  In the present embodiment, the cam follower 12B has a roller 64 made of an elastic material, and the roller 64 enters the cam groove 8A, and the diameter of the roller 64 is substantially equal to the width of the cam groove 8A. According to this embodiment, even when an impact is applied to the sliding cylinder 12, the roller 64 of the cam follower 12B is elastically deformed. This can more reliably prevent the cam follower 12B or the cam groove 8A from being damaged.

  In the present embodiment, the nut 74 of the straight advance piece 12A enters the auxiliary cam groove 8C with a gap formed between the nut 74 and the side surface of the auxiliary cam groove 8C. According to the present embodiment, during zooming, the sliding cylinder 12 is guided by the cam follower 12B and the cam groove 8A, so that a smooth zooming operation can be maintained. Then, when an impact is applied to the sliding cylinder 12 and the roller 64 of the cam follower 12B is elastically deformed, it comes into contact with the side of the auxiliary cam groove 8C of the rectilinear piece 12A, thereby preventing the cam follower 12B or the cam groove 8A from being damaged.

  Further, in the present embodiment, the material of the nut 74 of the straight advance piece 12 </ b> A is harder than the material of the roller 64. Accordingly, when the straight advancing piece 12A comes into contact with the side portion of the auxiliary cam groove 8C when an impact is applied, the impact acting on the roller 64 becomes very small, so that the roller 64 can be prevented from being damaged.

  In the present embodiment, the outer cylinder 14 having the vertical groove 14B formed radially outside the sliding cylinder 12 is arranged, and the cam groove 8A and the auxiliary cam groove 8C are formed radially inside the sliding cylinder 12. Although the case where the second rotary cylinder 8 is arranged has been described, the present invention is not limited to this, and the rotary cylinder in which the cam groove and the auxiliary cam groove are formed is arranged outside the sliding cylinder in the radial direction, and the vertical groove is formed. The present invention can be applied to a case where the vertical grooved cylinder is disposed radially inside the sliding cylinder.

  Further, in the present embodiment, the case where the top member 72 of the rectilinear top (second top member) 12A is inserted into the vertical groove 14B of the outer cylinder 14 has been described. However, the present invention is not limited to this. May be fitted into the cam groove.

  Further, in the present embodiment, the case where the cylindrical member is the outer cylinder 14 which does not rotate has been described, but the cylindrical member may be a rotating member. In this case, the present invention can be applied as long as the rotating cylinder (the second rotating cylinder 8) and the cylindrical member rotate at different rotation angles, thereby rotating the cylindrical member and the rotating cylinder relatively.

  Further, in the present embodiment, the case where the shape of the auxiliary cam groove 8C has the same locus as the cam groove 8A has been described, but the present invention is not limited to this. For example, the inclination of the auxiliary cam groove 8C on the object side may be smaller than that of the cam groove 8A. According to such a configuration, it is possible to more efficiently absorb the impact at the time of falling.

Reference Signs List 1 zoom lens barrel 2 mount 4 outer fixed barrel 4A rear outer fixed barrel 4B front outer fixed barrel 6 inner fixed barrel 6A front cylindrical portion 6B rear cylindrical portion 6a cam groove 6c cam groove 8 second rotary cylinder 8A cam groove 8B lateral groove 8C Auxiliary cam groove 8D Cam follower 10 First rotating cylinder 10A Front cylindrical part 10B Intermediate cylindrical part 10C Rear cylindrical part 10a Vertical groove 10b Cam groove 10c Horizontal groove 10d Cam groove 12 Sliding cylinder 12A Straight advancing piece 12B Cam follower 12C Through hole 12D Through hole 14 Outside Cylinder 14A rectilinear frame 14B vertical groove 14C frame 20 focus operation ring 22 zoom operation ring 30 first lens frame 32 second lens frame 32A frame 34 third lens frame 34A frame 36 fourth lens frame 36A frame 38 fifth lens frame 38A frame 40 throttle mechanism 60 screw 62 cam follower shaft 62A through hole 62B tip 64 roller 70 bis 72 piece member 72A through hole 74 nut A first lens group B second lens group C third lens group D fourth lens group E fifth lens group

Claims (5)

A sliding cylinder,
A rotating cylinder provided on one radial side of the sliding cylinder,
A cylindrical member provided on the other side in the radial direction of the sliding cylinder,
The sliding cylinder has a first top member protruding to one side in the radial direction, and a second top member protruding to the other side in the radial direction,
A cam groove into which the first top member enters is formed in the rotary cylinder,
A groove into which the second frame member enters is formed in the cylindrical member,
A zoom lens barrel in which the sliding barrel is extended in the optical axis direction by rotating the rotating barrel with respect to the barrel member,
The sliding cylinder has a protruding portion that protrudes to the other side in the radial direction of the second top member,
An auxiliary cam groove is formed on the rotary cylinder in addition to the cam groove,
The zoom lens barrel, wherein the protruding portion of the second frame member enters the auxiliary cam groove.   The zoom lens barrel according to claim 1, wherein the auxiliary cam groove has a shape having the same locus as the cam groove. The first top member has a roller made of an elastic material, and the roller enters the cam groove.
The zoom lens barrel according to claim 1, wherein a diameter of the roller is substantially equal to a width of the cam groove.   4. The zoom lens barrel according to claim 3, wherein the protrusion of the second top member enters the auxiliary cam groove with a gap formed between the protrusion and the side surface of the auxiliary cam groove. 5.   The zoom lens barrel according to claim 3, wherein a material of the protrusion is harder than a material of the roller.

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