JP2004170961A - Rotary ring support structure of lens barrel and rotary ring support structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To eliminate the backlash of a rotary ring in a lens barrel with simple, compact and inexpensive structure. <P>SOLUTION: The rotary ring support structure of the lens barrel is equipped with an annular member; 1st and 2nd rotary annular bodies supporting an optical element and supported to relatively move in an axial direction and integrally turn inside the annular member; a pair of peripheral direction surfaces formed on the annular member and turning front and rear in the axial direction and 1st and 2nd sliding surfaces formed on the 1st and the 2nd rotary annular bodies respectively and coming into contact with either surface of a pair of peripheral direction surfaces and the other; and an energizing means for energizing the 1st and the 2nd rotary annular bodies in opposite directions in the axial direction so as to make the 1st and the 2nd sliding surfaces abut on either surface of a pair of peripheral direction surfaces. <P>COPYRIGHT: (C)2004,JPO

Description

  The present invention relates to a rotating ring support structure such as a lens barrel, and more particularly to a rotating ring backlash removing structure.

Although play (backlash) is indispensable in the sliding portion of the movable member due to its structure, the backlash simultaneously affects the movement accuracy of the movable member. Therefore, various backlash removing structures have been proposed. For example, a lens barrel of a type in which a rotating ring such as a cam ring for moving a lens group in the optical axis direction is extended forward from a lens barrel storage position to a shooting area is known.

The mechanism for removing the backlash of the rotating ring as described above tends to have a complicated structure. Therefore, an object of the present invention is to eliminate backlash of a rotating ring, particularly in a state of use, in a device such as a lens barrel by a simple, compact and inexpensive structure.

  A rotating ring supporting structure for a lens barrel according to the present invention, comprising: an annular member; first and second rotating annular members supported inside the annular member so as to be relatively movable in an axial direction and to rotate integrally; An optical element supported via the first or second rotating annular body; a pair of circumferential surfaces formed on the annular member and facing the front and rear in the axial direction; and formed on the first and second rotating annular bodies, respectively. First and second sliding contact surfaces in contact with one and the other of the pair of circumferential surfaces; and the first and second rotating annular members are urged in opposite axial directions to form Biasing means for bringing the first and second sliding contact surfaces into contact with one and the other of the pair of circumferential surfaces;

  The pair of circumferential surfaces can be formed as opposing wall surfaces of a circumferential groove formed on the inner circumferential surface of the annular member. In this case, the first and second sliding contact surfaces are inserted into the circumferential groove, and are applied to one and the other of the opposing wall surfaces of the circumferential groove by the urging means.

  The biasing means may be at least one spring provided between the first and second rotating annular bodies. More specifically, it is preferable that at least one compression coil spring is provided between the opposed end faces of the first and second rotating annular bodies.

  It is preferable in terms of space efficiency that the second sliding contact surface of the second rotary annular body is formed in a region overlapping the first sliding contact surface in the circumferential direction.

  The first sliding contact surface is preferably formed on a plurality of radial projections formed at different positions in the circumferential direction on the first rotary annular body. It is preferable that three radial projections are provided at substantially equal intervals in the circumferential direction. Further, it is preferable that the radial protrusion has a concave portion in the axial direction, and the second sliding contact surface is formed on the second rotary annular body as a protrusion that can be stored in the concave portion.

  The rotating ring support structure of the present invention is configured such that the first and second rotating annular bodies rotate and retreat in an axial direction while rotating with respect to the annular member, and the rotational axis moves at least one of the front and rear moving ends due to the rotational advancing and retracting. It is particularly suitable for a lens barrel of a type that can be switched to a fixed position rotation state in which the lens barrel rotates without moving in the direction. In the fixed position rotation state, the first and second sliding contact surfaces are brought into contact with the pair of circumferential surfaces, so that the backlash between the first and second rotating annular bodies is removed and a favorable state is obtained. Optical performance can be exhibited.

  In a mode in which the first and second rotating annular bodies advance and retreat, a male helicoid and a female helicoid are formed on at least one outer peripheral surface of the first and second rotating annular bodies and the inner peripheral surface of the annular member, The male and female helicoids may be screwed together to drive the first and second rotating annular bodies, and the male and female helicoids may be unthreaded when switched to the home position.

  In the embodiment using the advance and retreat mechanism by helicoid, on the formation region of the female helicoid on the inner peripheral surface of the annular member, at least one helicoid-free region connected to the circumferential surface in parallel with the formation direction of the female helicoid, In a helicoid screwed state, it is preferable that the first and second sliding contact surfaces are positioned corresponding to the helicoid-free region. For example, by making the amount of protrusion of the first sliding contact surface from the outer peripheral surface of the first rotary annular body larger than that of the male helicoid, the amount of engagement between the first sliding contact surface and the circumferential surface (contact area) It is possible to increase the stability of the first and second rotating annular bodies at the time of fixed position rotation, but in this case, the interference between the first sliding contact surface and the female helicoid on the annular member side is taken into consideration. There is a need to. Here, a helicoid-free region is formed on the inner peripheral surface of the tubular member as a skew groove substantially parallel to the female helicoid, and the first sliding contact surface enters the skew groove when the helicoid is screwed. By doing so, interference between the first sliding contact surface and the female helicoid can be prevented.

  The lens barrel of the present invention further has a rectilinear ring supported inside the first and second rotary annular bodies so as to be capable of linearly moving in the axial direction. It is preferable to be coupled to the rectilinear ring so as to be relatively rotatable and move together in the axial direction via a rotation guide mechanism that fits loosely in the optical axis direction.

  The rotating ring support structure of the lens barrel according to the present invention also includes a first and second rotating annular members that can rotate integrally with each other about a rotation center axis parallel to the optical axis and relatively move in the optical axis direction; And an optical element that advances and retreats in the optical axis direction by rotation of the second rotating annular body; a non-rotating annular member that supports the first and second rotating annular bodies inside; the annular member and first and second rotations An inner / outer periphery of the annular member provided between the annular members to advance and retract between the front and rear moving ends in the optical axis direction with respect to the annular member when the first and second rotating annular bodies are rotated; A circumferential groove formed in the surface; provided on the outer peripheral surface of the first and second rotating annular bodies, the first and second rotating annular bodies are moved to at least one of the front and rear moving ends in the optical axis direction by the advance / retreat mechanism. The first and second rotating annular bodies are engaged with the circumferential grooves when they are rotated without moving in the optical axis direction. First and second rotating guide projections; biasing the first and second rotating annular bodies in directions away from each other and pressing the first and second rotating guide projections against opposing wall surfaces of the circumferential groove Means;

The present invention can also be applied to a rotating ring supporting structure other than a lens barrel by setting the movable element supported by the rotating ring to something other than an optical element such as a lens group.

According to the present invention described above, backlash of a rotating ring in a device such as a lens barrel can be removed by a simple, compact, and inexpensive structure.

[Overall description of zoom lens barrel]
First, the overall structure of the zoom lens barrel 71 of the present embodiment will be described with reference to FIGS. As shown in FIGS. 6 and 7, the zoom lens barrel 71 is mounted on the digital camera 70, and the photographing optical system includes, in order from the object side, a first lens group LG1, a shutter S and an aperture A, and a second lens. The optical system includes a group LG2, a third lens group LG3, a low-pass filter (filters) LG4, and a CCD (solid-state imaging device) 60. The optical axis of the photographing optical system is Z1. The photographing optical axis Z1 is parallel to a rotation center axis (hereinafter, referred to as a barrel center axis Z0) of each of the annular members forming the appearance of the zoom lens barrel 71, and is parallel to the barrel center axis Z0. It is eccentric downward. Zooming is performed by moving the first lens group LG1 and the second lens group LG2 back and forth along a predetermined trajectory in the direction of the photographing optical axis Z1, and focusing is performed by moving the third lens group LG3 in the same direction. In the following description, the term “optical axis direction” means a direction parallel to the photographing optical axis Z1 unless otherwise specified.

  As shown in FIGS. 6 and 7, the fixed ring 22 is fixed in the camera body 72, and the CCD holder 21 is fixed to the rear of the fixed ring 22. The CCD 60 is supported on the CCD holder 21 via a CCD base plate 62, and a low-pass filter LG 4 is supported in front of the CCD 60 via a filter holder 73 and a packing 61. The filter holder 73 is integrally formed as a part of the CCD holder 21. An LCD 20 for displaying images and photographing information is provided at the rear of the CCD holder 21.

  An AF lens frame (third group lens frame) 51 that holds the third lens group LG3 is supported in the fixed ring 22 so as to be able to move straight in the optical axis direction. That is, the front end and the rear end of a pair of AF guide shafts 52 and 53 parallel to the photographing optical axis Z1 are fixed to the fixed ring 22 and the CCD holder 21, respectively. Guide holes 51a and 51b formed in the AF lens frame 51 are slidably fitted respectively. In the present embodiment, the clearance between the AF guide shaft 53 and the guide hole 51b is larger than the clearance between the AF guide shaft 52 and the guide hole 51a. That is, the AF guide shaft 52 is a main (exactly accurate) guide shaft, and the AF guide shaft 53 is a sub (non-rotating) guide shaft. The AF nut 54 is screwed into a feed screw formed on the drive shaft of the AF motor 160. As shown in FIG. 1, the AF nut 54 has a rotation restricting protrusion 54a, the AF lens frame 51 has a guide groove 51m in the optical axis direction, and the rotation restricting protrusion 54a can slide with respect to the guide groove 51m. Is stuck in. The AF lens frame 51 further has a stopper projection 51n located behind the AF nut 54. The AF lens frame 51 is urged forward by an AF frame urging spring 55, and the forward movement end of the AF lens frame 51 is determined by the stopper projection 51 n abutting against the AF nut 54. When the AF nut 54 moves rearward in the optical axis direction, the AF lens frame 51 is pressed by the AF nut 54 and moves rearward. With the above structure, when the drive shaft of the AF motor 160 is rotated in the normal or reverse direction, the AF lens frame 51 is moved forward and backward in the optical axis direction. It is also possible to directly press the AF lens frame 51 (without using the AF nut 54) and move the AF lens frame 51 backward against the AF frame urging spring 55.

  As shown in FIG. 5, a zoom motor 150 and a reduction gear box 74 are supported on the upper part of the fixed ring 22. The reduction gear box 74 has a reduction gear train therein and transmits the driving force of the zoom motor 150 to the zoom gear 28. The zoom gear 28 is pivotally attached to the fixed ring 22 by a zoom gear shaft 29 parallel to the photographing optical axis Z1. The zoom motor 150 and the AF motor 160 are controlled by a camera control circuit 140 (FIG. 19) via a lens drive control FPC (flexible printed circuit) board 75 disposed on the outer peripheral surface of the fixed ring 22.

  On the inner peripheral surface of the fixed ring 22, a female helicoid 22a, three rectilinear guide grooves 22b parallel to the photographing optical axis Z1, three oblique grooves 22c parallel to the female helicoid 22a, and each oblique groove 22c are formed. A circumferential sliding groove 22d communicating with the front end is formed in the circumferential direction. The rotary sliding groove 22d is formed near the front end of the fixed ring 22, and the female helicoid 22a is not formed in the front annular region 22z immediately after the rotary sliding groove 22d (see FIG. 8).

  The helicoid ring 18 has a male helicoid 18a screwed into the female helicoid 22a and a rotary sliding projection 18b located in the oblique groove 22c and the rotary sliding groove 22d on the outer peripheral surface (FIG. 4, FIG. (FIG. 9). A spur gear portion 18c having gear teeth parallel to the photographing optical axis Z1 is formed on the male helicoid 18a, and the spur gear portion 18c is screwed with the zoom gear 28. Accordingly, when a rotational force is applied from the zoom gear 28 to the spur gear portion 18c, the helicoid ring 18 advances and retreats in the optical axis direction while rotating when the female helicoid 22a and the male helicoid 18a are in a screwing relationship with each other. When the male helicoid 18a moves, the male helicoid 18a is disengaged from the female helicoid 22a, and only the circumferential rotation about the lens barrel center axis Z0 is performed by the engagement relationship between the rotary sliding groove 22d and the rotary sliding protrusion 18b.

  The skew groove 22c is a relief groove formed to avoid interference between the rotary sliding protrusion 18b and the fixed ring 22 at the stage when the female helicoid 22a and the male helicoid 18a are screwed, and as shown in FIG. The row groove 22c is deeper than the bottom of the female helicoid 22a. In the female helicoid 22a, the circumferential interval between a pair of helicoid mountains sandwiching each of the oblique grooves 22c is wider than the circumferential interval between the other helicoid mountains, and the male helicoid 18a is mounted on the helicoid mountain having the wide circumferential interval. For engagement, the three helicoid peaks 18a-W located behind the rotary sliding protrusion 18b are circumferentially wider than the other helicoid peaks.

  The fixed ring 22 is further formed with a stopper insertion / removal hole 22e penetrating the outer peripheral surface and the rotary sliding groove 22d, and restricts the rotation of the helicoid ring 18 beyond the photographing area with respect to the stopper insertion / removal hole 22e. To be disassembled is removable.

  A rotation transmitting projection 15a (FIG. 11) projecting rearward from the rear end of the third outer cylinder 15 fits into a rotation transmitting recess 18d (FIGS. 4 and 10) formed on the inner peripheral surface of the front end of the helicoid ring 18. Have been. The rotation transmitting recesses 18d and the rotation transmitting projections 15a are provided at three positions at different positions in the circumferential direction, and the rotation transmitting projections 15a and the rotation transmitting recesses 18d corresponding to the circumferential positions correspond to the center axis of the lens barrel. Relative sliding in the direction along Z0 is connected so as to be possible, and relative rotation is not possible in the circumferential direction around the lens barrel center axis Z0. That is, the third outer cylinder 15 and the helicoid ring 18 rotate integrally. Further, the helicoid ring 18 is formed with a fitting recess 18e by cutting out a part of the rotation sliding protrusion 18b on the inner diameter side, and the fitting protrusion 15b fitted into the fitting recess 18e is rotated. When the sliding protrusion 18b engages with the rotating sliding groove 22d, it simultaneously engages with the rotating sliding groove 22d (see the upper half section of the lens barrel in FIG. 6).

  Between the third outer cylinder 15 and the helicoid ring 18, there are provided three separation-direction biasing springs 25 for biasing each other in the separation direction in the optical axis direction. The separation-direction urging spring 25 is formed of a compression coil spring, and its rear end is housed in a spring insertion recess 18 f that opens to the front end of the helicoid ring 18, and its front end contacts the spring-attached recess 15 c of the third outer cylinder 15. In contact. Pressing the fitting projection 15b toward the front wall surface of the rotary sliding groove 22d and pressing the rotary sliding protrusion 18b toward the rear wall surface of the rotary sliding groove 22d by the separating direction urging spring 25. Thus, the backlash of the third outer cylinder 15 and the helicoid ring 18 with respect to the fixed ring 22 in the optical axis direction is eliminated.

  On the inner peripheral surface of the third outer tube 15, a relative rotation guide protrusion 15d protruding in the inner diameter direction, a circumferential groove 15e centered on the lens barrel center axis Z0, and a third groove parallel to the photographing optical axis Z1. The roller fitting groove 15f is formed (FIGS. 4 and 11). A plurality of relative rotation guide protrusions 15d are provided at different positions in the circumferential direction. The roller fitting groove 15f is formed at a circumferential position corresponding to the rotation transmitting protrusion 15a, and a rear end portion thereof is opened rearward through the rotation transmitting protrusion 15a. A circumferential groove 18g centering on the lens barrel center axis Z0 is formed on the inner circumferential surface of the helicoid ring 18 (FIGS. 4 and 10). A straight guide ring 14 is supported inside the combined body of the third outer cylinder 15 and the helicoid ring 18. On the outer peripheral surface of the linear guide ring 14, three linear guide projections 14a protruding in the outer diameter direction in order from the rear in the optical axis direction, and a plurality of relative rotation guide projections 14b provided at different positions in the circumferential direction. 14c and a circumferential groove 14d centered on the lens barrel center axis Z0 are formed (FIGS. 4 and 12). The linear guide ring 14 is guided linearly in the optical axis direction with respect to the fixed ring 22 by engaging the linear guide protrusion 14a with the linear guide groove 22b. Further, the third outer cylinder 15 engages the circumferential groove 15e with the relative rotation guide protrusion 14c and engages the relative rotation guide protrusion 15d with the circumferential groove 14d, so that the third outer cylinder 15 is It is rotatably connected. The circumferential groove 15e and the relative rotation guide protrusion 14c, and the circumferential groove 14d and the relative rotation guide protrusion 15d are each loosely fitted so as to be relatively movable in the optical axis direction. Further, the helicoid ring 18 is also relatively rotatably coupled to the rectilinear guide ring 14 by engaging the circumferential groove 18g with the relative rotation guide protrusion 14b. The circumferential groove 18g and the relative rotation guide protrusion 14b are loosely fitted so as to be able to relatively move relatively in the optical axis direction.

  The linear guide ring 14 is formed with three roller guide through grooves 14e penetrating the inner peripheral surface and the outer peripheral surface. As shown in FIG. 12, each of the roller guide through grooves 14e includes parallel front and rear circumferential grooves 14e-1 and 14e-2 formed in the circumferential direction, and both circumferential grooves 14e-1 and 14e-2. And a lead groove 14e-3 for connecting the A cam ring roller 32 provided on the outer peripheral surface of the cam ring 11 is fitted into each roller guide through groove 14e. The cam ring rollers 32 are fixed to the cam ring 11 via roller fixing screws 32a, and three cam ring rollers are provided at different positions in the circumferential direction. The cam ring roller 32 further penetrates the roller guide through groove 14e and is fitted in the roller fitting groove 15f on the inner peripheral surface of the third outer cylinder 15. Near the front end of each roller fitting groove 15f, three roller pressing pieces 17a provided on the roller urging spring 17 are fitted (FIG. 11). The roller pressing piece 17a comes into contact with the cam ring roller 32 and presses backward when the cam ring roller 32 engages with the circumferential groove portion 14e-1, and the cam ring roller 32 and the roller guide through groove 14e (in the circumferential direction). Backlash between the groove 14e-1) is removed.

  From the structure described above, the manner in which the fixed ring 22 extends from the cam ring 11 is understood. That is, when the zoom gear 28 is rotationally driven by the zoom motor 150 in the lens barrel extending direction, the helicoid ring 18 is extended forward while rotating due to the relationship between the female helicoid 22a and the male helicoid 18a. The helicoid ring 18 and the third outer cylinder 15 are relatively rotatable and rotatable with respect to the rectilinear guide ring 14 due to the engagement relationship between the circumferential grooves 14d, 15e and 18g and the relative rotation guide projections 15d, 14c and 14b, respectively. The third outer cylinder 15 is also extended forward while rotating in the same direction when the helicoid ring 18 is rotationally extended since the coupling is performed so as to move together in the axial direction (the direction along the lens barrel center axis Z0). Then, the straight guide ring 14 moves straight forward together with the helicoid ring 18 and the third outer cylinder 15. The rotational force of the third outer cylinder 15 is transmitted to the cam ring 11 via the roller fitting groove 15f and the cam ring roller 32. Since the cam ring roller 32 is also fitted into the roller guide through groove 14e, the cam ring 11 is extended forward with respect to the straight guide ring 14 while rotating according to the shape of the lead groove 14e-3. As described above, since the rectilinear guide ring 14 itself is also rectilinearly moving forward together with the third outer cylinder 15 and the helicoid ring 18, as a result, the cam ring 11 is provided with the rotation extension according to the lead groove 14e-3 and the rectilinear guide. The moving amount in the optical axis direction is given by adding the amount of forward movement of the ring 14 to the front.

  The above-described feeding operation is performed while the male helicoid 18a and the female helicoid 22a are screwed together, and at this time, the rotary sliding projection 18b moves in the oblique groove 22c. When the helicoid ring 18 and the third outer cylinder 15 are extended by a predetermined amount, the screw engagement between the male helicoid 18a and the female helicoid 22a is released, and the rotary sliding projection 18b and the fitting projection 15b are eventually rotated from the oblique groove 22c. It enters the moving groove 22d. Then, since the rotation repetition output by the helicoid does not work, the helicoid ring 18 and the third outer cylinder 15 are moved in the optical axis direction by the engagement relationship between the rotation sliding protrusion 18b and the fitting protrusion 15b and the rotation sliding groove 22d. Only rotation is performed at a fixed position. At substantially the same time when the rotary sliding protrusion 18b enters the rotary sliding groove 22d from the oblique groove 22c, the cam ring roller 32 enters the circumferential groove 14e-1 of the through guide groove 14e. Then, no forward moving force is applied to the cam ring 11, and the cam ring 11 only rotates at a fixed position according to the rotation of the third outer cylinder 15.

  When the zoom gear 28 is driven to rotate in the lens barrel housing direction, the reverse operation is performed. When the helicoid ring 18 is rotated until the cam ring roller 32 enters the circumferential groove 14e-2 of the roller guide through groove 14e, each of the above-mentioned lens barrel members is retracted to the position shown in FIG.

  Subsequently, the structure before the cam ring 11 will be described. On the inner peripheral surface of the rectilinear guide ring 14, three first rectilinear guide grooves 14f and six second rectilinear guide grooves 14g parallel to the photographing optical axis Z1 are formed at different positions in the circumferential direction. . The first rectilinear guide grooves 14f include a pair of grooves located on both sides of three of the six second rectilinear guide grooves 14g. The three crotch-shaped protrusions 10a (FIGS. 3 and 15) provided on the front panel are slidably engaged. On the other hand, the six rectilinear guide projections 13a (FIGS. 2 and 17) protruding from the outer peripheral surface of the rear end of the second outer cylinder 13 are slidably engaged with the second rectilinear guide grooves 14g. I have. Therefore, both the second outer cylinder 13 and the second group straight guide ring 10 are guided straight through the straight guide ring 14 in the optical axis direction.

  The second group straight guide ring 10 is a member for guiding the second group lens moving frame 8 that supports the second lens group LG2 straight, and the second outer cylinder 13 is a first outer cylinder that supports the first lens group LG1. It is a member for guiding the cylinder 12 straight.

  First, the support structure of the second lens group LG2 will be described. The second group straight guide ring 10 has three straight guide keys 10c protruding forward from a ring portion 10b connecting the three crotch-shaped protrusions 10a (FIGS. 3 and 15). As shown in FIGS. 6 and 7, the outer edge of the ring portion 10b can rotate relative to the circumferential groove 11e formed on the inner peripheral surface of the rear end of the cam ring 11, but cannot move relative to the optical axis. The straight guide key 10c is extended inside the cam ring 11. Each of the rectilinear guide keys 10 c has a pair of guide surfaces parallel to the photographing optical axis Z <b> 1, and the guide surfaces are formed by the rectilinear guide grooves of the second lens group moving frame 8 supported inside the cam ring 11. The second group lens moving frame 8 is guided linearly in the axial direction by engaging with the lens 8a. The rectilinear guide groove 8 a is formed on the outer peripheral surface side of the second group lens moving frame 8.

  The second group straight guide ring 10 is provided with three straight guide keys 10c at different positions in the circumferential direction, and one of the straight guide keys 10c-W is provided with an exposure control FPC (flexible In order to also serve as a support member for the printed circuit board 77, the width is circumferentially wider than the remaining two straight guide keys 10c. The wide straight guide key 10c-W is formed with a PWB through hole 10d penetrating in the radial direction by partially cutting out the vicinity of the connection portion with the ring portion 10b, as shown in FIG. The flexible PWB 77 extends from the rear of the ring portion 10b to the outer peripheral surface side of the linear guide key 10c-W through the PWB through hole 10d, and is bent rearward at the distal end of the linear guide key 10c-W. Correspondingly, one of the three rectilinear guide grooves 8a is a wide rectilinear guide groove 8a-W to which the wide rectilinear guide key 10c-W can be engaged. The central portion of the straight guide groove 8a-W is a through portion through which the flexible PWB 77 for exposure control can pass, and a bottom portion for supporting the straight guide key 10c-W is provided on both sides of the through portion. Is formed. On the other hand, the remaining two rectilinear guide grooves 8 a are both bottomed grooves formed on the outer peripheral surface side of the second group lens moving frame 8. The second group lens moving frame 8 and the second group straight guide ring 10 can be combined only in a specific rotation phase in which the straight guide keys 10c-W can engage with the straight guide grooves 8a-W.

  A second group guide cam groove 11 a is formed on the inner peripheral surface of the cam ring 11. As shown in FIG. 14, the second group guide cam groove 11a includes a front cam groove 11a-1 and a rear cam groove 11a-2 whose positions are different in the optical axis direction and the circumferential direction. Each of the front cam groove 11a-1 and the rear cam groove 11a-2 is a cam groove formed by tracing the same base locus α, but does not cover the entire area of the base locus α. The front cam groove 11a-1 and the rear cam groove 11a-2 differ from each other in a part of the area occupied on the basic locus α. The basic trajectory is a conceptual cam groove shape including all the lens barrel use areas (use areas) including the zoom area and the storage area, and the lens barrel assembly / disassembly area. That is, the lens barrel use area is an area in which the movement of the second lens group moving frame 8 can be controlled by the cam groove shape, and is used to distinguish it from the assembly and disassembly area. Further, the zoom area is an area for controlling movement between the wide end and the tele end particularly in the lens barrel use area, and is used to distinguish it from the storage area. When a pair of the front cam groove 11a-1 and the rear cam groove 11a-2 are formed as one group, the cam ring 11 is formed with three groups of second group guide cam grooves 11a at equal intervals in the circumferential direction.

  The second group cam follower 8b provided on the outer peripheral surface of the second group lens moving frame 8 is engaged with the second group guide cam groove 11a. Similarly to the second group guide cam groove 11a, the second group cam followers 8b are also circumferentially equally spaced as a group of a pair of front cam followers 8b-1 and rear cam followers 8b-2 whose positions are different in the optical axis direction and the circumferential direction. The front cam followers 8b-1 engage with the front cam grooves 11a-1, and the rear cam followers 8b-2 engage with the rear cam grooves 11a-2 in the optical axis direction. A circumferential interval is defined.

  Since the second group lens moving frame 8 is guided linearly in the optical axis direction via the second group linear guide ring 10, when the cam ring 11 rotates, the second group lens moving frame 8 is driven in accordance with the second group guide cam groove 11a. It moves along a predetermined trajectory in the axial direction.

  Inside the second group lens moving frame 8, a second group lens frame 6 that holds the second lens group LG2 is supported. The second group lens frame 6 is supported by a pair of second group lens frame support plates 36 and 37 via a second group rotation shaft 33, and the second group frame support plates 36 and 37 are supported plate fixing screws 66. To the second group lens moving frame 8. The second-group rotation axis 33 is parallel to the imaging optical axis Z1 and is eccentric with respect to the imaging optical axis Z1, and the second-group lens frame 6 has the second lens group LG2 with the second-group rotation axis 33 as the rotation center. A photographing position (FIG. 6) where the optical axis of the second lens group LG2 coincides with the photographing optical axis Z1, and a retracting position (FIG. 6) for displacing the optical axis of the second lens group LG2 from the photographing optical axis Z1 to the retracted optical axis Z2. 7). The second group lens moving frame 8 is provided with a rotation restricting pin 35 for restricting the second group lens frame 6 from rotating at the photographing position. The second group lens frame 6 is moved by a second group lens frame returning spring 39. It is urged to rotate in the direction of contact with the rotation restricting pin 35. The axial pressing spring 38 performs backlash removal of the second lens group frame 6 in the optical axis direction.

  The second group lens frame 6 moves integrally with the second group lens moving frame 8 in the optical axis direction. A cam projection 21a (FIG. 4) projects forward from the CCD holder 21 at a position where it can be engaged with the second group lens frame 6. As shown in FIG. When it moves and approaches the CCD holder 21, the cam surface formed at the tip of the cam projection 21a engages with the second lens group frame 6 and rotates to the above-mentioned retracted position for storage.

  Subsequently, a support structure of the first lens group LG1 will be described. On the inner peripheral surface of the second outer cylinder 13 guided straight in the optical axis direction via the straight guide ring 14, three rectilinear guide grooves 13b are formed in the optical axis direction at positions different in the circumferential direction. The three engagement projections 12a formed on the outer peripheral surface near the rear end of the first outer cylinder 12 are slidably fitted into the respective linear guide grooves 13b (FIGS. 2, 17, and 18). reference). That is, the first outer cylinder 12 is guided linearly in the optical axis direction via the straight guide ring 14 and the second outer cylinder 13. The second outer cylinder 13 has an inner peripheral flange 13c on the inner peripheral surface in the vicinity of the rear end thereof, and the inner peripheral flange 13c slides in a circumferential groove 11c provided on the outer peripheral surface of the cam ring 11. By engaging as much as possible, the second outer cylinder 13 is coupled to the cam ring 11 so as to be rotatable relative to the cam ring 11 and not to move relative to the optical axis. On the other hand, the first outer cylinder 12 has three first group rollers (cam followers) 31 protruding in the inner diameter direction, and each first group roller 31 is formed on the outer peripheral surface of the cam ring 11 as one group. It is slidably fitted in the guide cam groove 11b.

  The first lens barrel 1 is supported in the first outer cylinder 12 via a first lens adjusting ring 2. The first lens group LG1 is fixed to the first group lens frame 1, and a male adjustment screw 1a formed on the outer peripheral surface thereof is screwed with a female adjustment screw 2a formed on the inner peripheral surface of the first group adjustment ring 2. . By adjusting the screw position of the adjusting screw, the position of the first lens group frame 1 with respect to the first lens group adjusting ring 2 can be adjusted in the optical axis direction.

  The first group adjusting ring 2 has a pair of (only one is shown in FIG. 2) guide protrusions 2 b protruding in the outer diameter direction, and the pair of guide protrusions 2 b are formed on the inner peripheral surface side of the first outer cylinder 12. Are slidably engaged with the pair of first group adjusting ring guide grooves 12b formed in the first group. The first group adjustment ring guide groove 12b is formed in parallel with the photographing optical axis Z1, and the first group adjustment ring 2 and the first group lens frame 1 are formed by the engagement relationship between the first group adjustment ring guide groove 12b and the guide projection 2b. The combined body can be moved back and forth in the optical axis direction with respect to the first outer cylinder 12. The first group retaining ring 3 is further fixed to the first outer cylinder 12 with a retaining ring fixing screw 64 so as to close the front of the guide protrusion 2b. A first-group urging spring 24 composed of a compression coil spring is provided between the spring receiving portion 3a of the first-group retaining ring 3 and the guide protrusion 2b. It is biased rearward in the axial direction. The first group adjusting ring 2 is formed by engaging an engaging claw 2c protruding from an outer peripheral surface near a front end portion thereof with a front surface (a surface visible in FIG. 2) of the first group retaining ring 3. The maximum movement position in the optical axis direction rearward relative to the one outer cylinder 12 is regulated (see the upper half section in FIG. 6). On the other hand, by compressing the first-group urging spring 24, the first-group adjusting ring 2 can move a little forward in the optical axis direction.

  A shutter unit 76 having a shutter S and an aperture A is supported between the first lens group LG1 and the second lens group LG2. The shutter unit 76 is supported inside the second-group lens moving frame 8, and the shutter S and the aperture A have a fixed air gap between the second lens group LG2. Two actuators 131 and 132 (FIG. 19) for driving the shutter S and the aperture A are respectively arranged at front and rear positions with the shutter unit 76 interposed therebetween. An exposure control FPC (flexible printed circuit) board 77 for connecting to the control circuit 140 extends. The exposure control flexible FPC 77 does not actually exist at the position of the lower half section (wide end) in FIG. 6, but is shown for easy understanding of the positional relationship with other members.

  In addition to the shutter S, a lens barrier mechanism is provided at the front end of the first outer cylinder 12 for closing the photographing aperture when not photographing to protect the photographing optical system (first lens group LG1). The lens barrier mechanism includes a pair of barrier blades 104 and 105 rotatable about a rotation axis provided at a position eccentric to the lens barrel center axis Z0, and biases the barrier blades 104 and 105 in a closing direction. A pair of barrier urging springs 106, a barrier drive ring 103 that is rotatable about a lens barrel center axis Z0 and engages and opens the barrier blades 104, 105 by rotation in a predetermined direction, and the barrier drive ring. A barrier drive ring biasing spring 107 for biasing the rotary shaft 103 in the barrier opening direction is provided, and a barrier pressing plate 102 located between the barrier blades 104 and 105 and the barrier drive ring 103. The urging force of the barrier driving ring urging spring 107 is set stronger than the urging force of the barrier urging spring 106, and when the zoom lens barrel 71 is extended to the zoom region (FIG. 6), the barrier driving ring urging spring 107 is turned on. The biasing spring 107 holds the barrier drive ring 103 at the barrier opening angular position, and the barrier blades 104 and 105 are opened against the barrier biasing spring 106. Then, while the zoom lens barrel 71 is moving from the zoom region to the storage position (FIG. 7), the barrier drive ring pressing surface 11d (FIGS. 3 and 13) of the cam ring 11 causes the barrier drive ring 103 to be opposed to the barrier opening direction. The barrier drive ring 103 is disengaged from the barrier blades 104 and 105 by being forcedly rotated in the direction, and the barrier blades 104 and 105 are closed by the urging force of the barrier urging spring 106. The front of the lens barrier mechanism is covered by a barrier cover 101 (decorative plate).

  The entire extension and storage operation of the zoom lens barrel 71 having the above structure will be described with reference to FIGS. 6, 7, and 19. FIG. FIG. 19 conceptually shows the relationship between the main members of the zoom lens barrel 71, where "S" in parentheses after the reference numeral of each member is a fixed member, and "L" is an optical axis direction. A member that performs only linear movement, “R” means a member that performs only rotation, and “RL” means a member that moves in the optical axis direction while rotating. A member in which two symbols are written in parentheses means that the operation mode is switched at the time of feeding and storage.

  The steps up to the stage in which the cam ring 11 is extended from the storage position to the home position rotation state have already been described, and thus will be briefly described. 7, the zoom lens barrel 71 is completely stored in the camera body 72, and the front surface of the camera 70 has a flat shape in which the zoom lens barrel 71 does not protrude. When the zoom gear 28 is rotationally driven in the extension direction by the zoom motor 150 from the lens barrel stored state, the combined body of the helicoid ring 18 and the third outer cylinder 15 is rotated and extended in accordance with the helicoid (the male helicoid 18a and the female helicoid 22a). The straight guide ring 14 moves straight forward together with the third outer cylinder 15 and the helicoid ring 18. At this time, the cam ring 11 to which the rotational force is applied by the third outer cylinder 15 has a lead structure (a cam ring roller) provided between the linear guide ring 14 and the linear movement forward. 32, the combined movement with the extended portion by the lead groove portion 14e-3) is performed. When the helicoid ring 18 and the cam ring 11 are extended to a predetermined position in front, the functions of the respective rotating and extending structures (helicoid, lead) are released, and only the circumferential rotation about the lens barrel center axis Z0 is performed. become.

  When the cam ring 11 rotates, the second-group lens moving frame 8 guided straight through the second-group straight guide ring 10 is rotated in the optical axis direction by the relationship between the second-group cam follower 8b and the second-group guide cam groove 11a. Is moved along a predetermined locus. In the lens barrel storage state of FIG. 7, the second group lens frame 6 in the second group lens moving frame 8 is a storage retracting position eccentric upward from the photographing optical axis Z1 by the action of the cam projection 21a protruding from the CCD holder 21. And the second lens group LG2 is located at the retracted optical axis Z2. The second group lens frame 6 separates from the cam projection 21a while the second group lens moving frame 8 is being extended to the zoom region, and moves the optical axis of the second lens group LG2 by the urging force of the second group lens frame return spring 39. It is rotated to a photographing position (FIG. 6) that is coincident with the photographing optical axis Z1. Thereafter, the second group lens frame 6 is held at the photographing position until the zoom lens barrel 71 is moved to the storage position again.

  When the cam ring 11 rotates, outside the cam ring 11, the first outer cylinder 12, which is guided straight through the second outer cylinder 13, has a relationship between the first group roller 31 and the first group guide cam groove 11 b. Is moved along a predetermined locus in the optical axis direction.

  That is, the extension positions of the first lens group LG1 and the second lens group LG2 with respect to the image pickup surface (CCD light receiving surface) are determined by the amount of forward movement of the cam ring 11 with respect to the fixed ring 22 and the first The latter is determined as the sum of the cam extension of the outer cylinder 12 and the latter is the sum of the forward movement of the cam ring 11 with respect to the fixed ring 22 and the cam extension of the second lens unit moving frame 8 with respect to the cam ring 11. Decided. Zooming is performed by moving the first lens group LG1 and the second lens group LG2 on the photographing optical axis Z1 while changing the air gap between them. When the lens barrel is extended from the storage position of FIG. 7, the wide end is first extended as shown in the lower half section of FIG. 6, and when the zoom motor 150 is further driven in the lens barrel extending direction, the upper half section of FIG. As shown in FIG. As can be seen from FIG. 6, the zoom lens barrel 71 of the present embodiment has a large distance between the first lens group LG1 and the second lens group LG2 at the wide end, and a large distance between the first lens group LG1 and the second lens at the telephoto end. The group LG2 moves in the approaching direction of each other, and the interval decreases. Such a change in the air gap between the first lens group LG1 and the second lens group LG2 is given by the locus of the second group guide cam groove 11a and the first group guide cam groove 11b. In the zoom region (zooming use region) between the tele end and the wide end, the cam ring 11, the third outer cylinder 15, and the helicoid ring 18 perform only the above-described fixed position rotation, and do not advance or retreat in the optical axis direction.

  In the zoom region, by driving the AF motor 160 according to the subject distance, the third lens group LG3 (AF lens frame 51) moves along the photographing optical axis Z1 to perform focusing.

  When the zoom motor 150 is driven in the lens barrel storage direction, the zoom lens barrel 71 performs a storage operation reverse to that at the time of the above-described extension, and is stored in the camera body 72 completely (FIG. 7). Moved to During the movement to the storage position, the second group lens frame 6 is rotated to the storage retracting position by the cam projection 21a, and retracts together with the second group lens movement frame 8. When the zoom lens barrel 71 is moved to the storage position, the second lens group LG2 is stored at the same position in the optical axis direction as the third lens group LG3 and the low-pass filter LG4 (overlaps in the radial direction of the barrel). . The retracted structure of the second lens group LG2 during storage makes it possible to shorten the storage length of the zoom lens barrel 71 and reduce the thickness of the camera body 72 in the left-right direction in FIG.

  The digital camera 70 includes a zoom finder linked to the zoom lens barrel 71. The zoom finder obtains power from the helicoid ring 18 by meshing the finder gear 30 with the spur gear portion 18c. When the helicoid ring 18 performs the above-described fixed position rotation in the zoom region, the finder gear receives the rotational force and receives the power. 30 rotates. The finder optical system has an objective window 81a, a first movable variable power lens 81b, a second movable variable power lens 81c, a prism 81d, an eyepiece 81e, and an eyepiece window 81f, and has first and second movable variable power. Zooming is performed by moving the lenses 81b and 81c along a predetermined locus along the optical axis Z3 of the finder objective system. The optical axis Z3 of the finder objective system is parallel to the photographing optical axis Z1. The holding frames 83 and 84 of the movable variable power lenses 81b and 81c are guided by guide shafts 85 and 86 (see FIGS. 6 and 7 so as to overlap and appear as one) so as to be movable in the direction of the optical axis Z3, and The moving force is given by a cam gear 90 (FIG. 5) rotatable about a rotation center axis parallel to the optical axis Z3. A reduction gear train is provided between the cam gear 90 and the finder gear 30. When the finder gear 30 rotates, the cam gear 90 is rotated, and as a result, the movable zoom lenses 81b and 81c move forward and backward. The above components of the zoom finder are sub-assembled as a finder unit 80 shown in FIG.

[Description of Characteristic Features of the Present Invention]
As described above, in the zoom lens barrel 71, the helicoid ring (first rotating annular body) 18 and the third outer cylinder are in the middle of the transition from the lens barrel storage state in FIG. 7 to the use state (zoom area) in FIG. The (second rotary annular body) 15 is rotated forward and rotated, and in use, the helicoid ring 18 and the third outer cylinder 15 are rotated at fixed positions without moving in the optical axis direction. A structure for supporting the helicoid ring 18 and the third outer cylinder 15, particularly a structure for removing a backlash from the fixed ring (annular member) 22 in the photographing state will be described with reference to FIG.

  As described above, the third outer cylinder 15 and the helicoid ring 18 are coupled to rotate integrally with each other in the rotation direction by engaging the rotation transmission projection 15a with the rotation transmission recess 18d, and rotate the rotation transmission projection 15a. At the same time, the fitting projection 15b fits into the fitting recess 18e formed on the inner diameter portion of the rotary sliding protrusion (radial projection) 18b in the rotation phase in which the engagement is made with the rotation transmitting recess 18d (FIG. 30, FIG. See FIG. 31). In the rotation phase of the third outer cylinder 15 and the helicoid ring 18 in which the rotation transmitting projection 15a and the fitting projection 15b are engaged with the rotation transmitting recess 18d and the fitting recess 18e, respectively, a spring insertion recess formed at the front end of the helicoid ring 18 is provided. The separation-direction urging spring (urging means) 25 housed in 18 f is positioned corresponding to the spring-abutting recess 15 c at the rear end of the third outer cylinder 15.

  The helicoid ring 18 and the third outer cylinder 15 also have respective fitting relations between the relative rotation guide projections (rotation guide mechanisms) 14b, 14c and 15d and the circumferential grooves (rotation guide mechanisms) 18g, 15e and 14d. It is connected to the straight guide ring (straight ring) 14 so as to be relatively rotatable. As shown in FIGS. 32 to 35, the relative rotation guide projections 14b, 14c and 15d and the circumferential grooves 18g, 15e and 14d are loosely fitted in the optical axis direction, and the helicoid ring 18 and the third Each of the outer cylinders 15 is slightly movable in the optical axis direction with respect to the straight guide ring 14. That is, although the helicoid ring 18 and the third outer cylinder 15 are restricted from being completely divided in the optical axis direction through the straight guide ring 14, a relative movement in the optical axis direction by a small amount is possible at the same time. Has become. The amount of play (clearance) in the optical axis direction with respect to the straight guide ring 14 is larger on the helicoid ring 18 side than on the third outer cylinder 15 side.

  When the third outer cylinder 15 and the helicoid ring 18 are relatively rotatably coupled to the linear guide ring 14, the distance between the spring contact recess 15c and the spring insertion recess 18f in the optical axis direction is free of the separation direction biasing spring 25. It becomes narrower than the length, and the separation-direction urging spring 25 is held between the opposing end surfaces of the third outer cylinder 15 and the helicoid ring 18 in a compressed state. Due to the restoring force, the compressed separating-direction urging spring 25 moves the third outer cylinder 15 and the helicoid ring 18 away from each other, that is, moves the third outer cylinder 15 forward in the optical axis direction and moves the helicoid ring 18 backward in the optical axis direction. Energize.

  As shown in FIGS. 24 to 28, three sloping grooves (helicoid-free region) 22 c formed on the inner peripheral surface of the fixed ring 22 are respectively opposed to a pair of opposing sloping surfaces 22 c − A, 22c-B, and the three rotary sliding protrusions 18b of the helicoid ring 18 respectively have a pair of end slopes 18b-A, 18b-B opposed to the opposed slopes 22c-A, 22c-B. Have. Opposing sloping surfaces 22c-A and 22c-B of the sloping groove 22c are formed in a direction parallel to the helicoid peak of the female helicoid 22a, and end slopes 18b-A and 18b of the rotary sliding protrusion 18b. -B has a shape that does not interfere with each of the opposing sloping surfaces 22c-A and 22c-B. Specifically, when the male helicoid (advancing / retracting mechanism) 18a and the female helicoid (advancing / retracting mechanism) 22a are screwed together as shown in FIG. The end slopes 18b-A and 18b-B of the rotary sliding projection 18b are not pinched (engaged). In order to make only one rotation sliding projection 18b abut on the lens barrel stopper 26, a part of the end slope 18b-A is cut away to form a stopper abutment surface 18b-E parallel to the optical axis. Have been.

  In the three rotational sliding grooves (circumferential grooves) 22d following the skew grooves 22c, a pair of parallel rotational guide surfaces (circumferential surfaces) 22d-A and 22d-B, which are spaced apart and opposed in the optical axis direction, respectively. The three rotating sliding protrusions 18b formed on the helicoid ring 18 side are formed as opposing wall surfaces, and the front sliding surface 18b-C and the rear sliding surface (the first sliding surface) that can slide on the rotating guide surfaces 22d-A and 22d-B, respectively. (One sliding contact surface) 18b-D. As shown in FIG. 31, the fitting recess 18e for housing the fitting projection 15b is formed by partially cutting out the front sliding surface 18b-C side of each rotary sliding projection 18b. The front surface of the fitting protrusion 15b is in contact with a sliding contact surface (second sliding contact surface) 15b-A facing the rotation guide surface 22d-A in a state where the fitting protrusion 15b is housed in the fitting recess 18e. Has become.

  20 and 24, the rotary sliding projection 18b of the helicoid ring 18 is located in the oblique groove 22c of the fixed ring 22, and the end slopes 18b-A and 18b-B are respectively located. It is opposed to the opposing sloping surfaces 22c-A and 22c-B in a slightly separated state. In this lens barrel storage state, the male helicoid 18a and the female helicoid 22a are in a screwed state. Accordingly, when rotation is given to the helicoid ring 18 in the lens barrel extending direction (upward in FIG. 20) by the zoom gear 28 meshing with the spur gear portion 18c, the helicoid ring 18 is moved forward in the optical axis direction due to the relationship between the male helicoid 18a and the female helicoid 22a. (Left side in the figure). During the rotation of the helicoid ring 18, the rotary sliding projection 18b moves in the oblique groove 22c, so that the rotary sliding projection 18b does not interfere with the female helicoid 22a of the fixed ring 22.

  When the rotary sliding projection 18b is located in the oblique groove 22c, the position of the fitting projection 15b in the optical axis direction is not restricted by the oblique groove 22c. In the rotary sliding projection 18b, the opposed sloping surfaces 22c-A and 22c-B face the opposed sloping surfaces 22c-A and 22c-B of the skew groove 22c, but the front sliding surface 18b-A. Positions C and the rear sliding surfaces 18b-D are not restricted by the oblique grooves 22c in the optical axis direction. Accordingly, as shown in FIGS. 34 and 35, the third outer cylinder 15 and the helicoid ring 18 urged in the separating direction by the urging force of the separating direction urging spring 25 are connected to the respective relative rotation guide protrusions. (14b, 14c and 15d) and the circumferential grooves (18g, 15e and 14d) are slightly separated in the optical axis direction according to the clearance. In this state, since the compression degree of the separating direction urging spring 25 is low, the action of the urging force is weak, and the distance between the third outer cylinder 15 and the helicoid ring 18 in the optical axis direction is relatively loose, but While the moving projection 18b is located in the skewed groove 22c, it is in the middle of reaching the shooting state (zoom area) from the storage position and shooting is not performed, so there is no practical problem. Rather, in the zoom lens barrel of the compact camera, the retracted state including the power-off state is longer (longer in time) than the photographing state. As in the case of the spring 25, it is preferable not to apply a strong load other than in the photographing state because the possibility of deterioration over time or the like is reduced. Further, the resistance at the time of extension from the storage position to the shooting state can be suppressed to be small.

  When the rotary sliding protrusion 18b moves to the forefront of the skew groove 22c, it comes off the skew groove 22c and enters the rotary slide groove 22d. The formation region in the optical axis direction of the male helicoid 18a and the female helicoid 22a is set so as to release the screwing at this time. Specifically, on the inner peripheral surface of the fixed ring 22, the formation region of the rotary sliding groove 22d and the front annular region 22z behind it do not have the female helicoid 22a, and the optical axis direction of the front annular region 22z Is set to be larger than the formation area of the male helicoid 18a in the optical axis direction. On the other hand, on the outer peripheral surface of the helicoid ring 18, when the rotary sliding protrusion 18b engages with the rotary sliding groove 22d, the rear male helicoid 18a is positioned (overlaps) in the front annular region 22z. The distance between the male helicoid 18a and the rotary sliding protrusion 18b in the optical axis direction is determined. Therefore, when the rotary sliding projection 18b engages with the rotary sliding groove 22d, the screwing of the male helicoid 18a and the female helicoid 22a is released, and a repetitive output in the optical axis direction acts on the rotating helicoid ring 18. No longer. Thereafter, the helicoid ring 18 rotates only in the circumferential direction in accordance with the rotation of the zoom gear 28 in the lens barrel extending direction. As shown in FIG. 21, the zoom gear 28 keeps meshing with the spur gear portion 18c even after the helicoid ring 18 has been rotated to the home position, and continuously rotates the helicoid ring 18 at the time of rotation. Can be.

  The state of FIGS. 21 and 25 in which the helicoid ring 18 rotates at a fixed position and the rotation slide protrusion 18b slightly advances in the rotation slide groove 22d is the wide end of the zoom lens barrel 71. As shown in FIG. 32, when the rotary sliding protrusion 18b moves into the rotary sliding groove 22d, the fitting protrusion 15b located at the same circumferential position as the rotary sliding protrusion 18b is simultaneously stored in the rotary sliding groove 22d. The sliding contact surface 15b-A of the fitting projection 15b is pressed against the front rotation guide surface 22d-A by the urging force of the separation direction urging spring 25, and the rear sliding surface 18b-D of the rotary sliding projection 18b is pressed. It is pressed against the rear rotation guide surface 22d-B. The distance between the rotation guide surfaces 22d-A and 22d-B in the optical axis direction before and after the rotation slide groove 22d is larger than that when the rotation slide protrusion 18b and the fitting protrusion 15b are located in the oblique groove 22c. The sliding protrusion 18b and the fitting protrusion 15b are set so as to be forcibly approached in the optical axis direction. Accordingly, the degree of compression of the separating direction urging spring 25 is increased, and the sliding protrusion 18b and the fitting protrusion 15b are rotationally slid. A stronger urging force acts on the projection 18b than when the lens barrel is stored. Thereafter, while both the rotary sliding projection 18b and the fitting projection 15b are engaged with the rotary sliding groove 22d, the fitting projection 15b and the rotary sliding projection 18b are urged by the biasing force of the separation direction biasing spring 25. As a result, the positions of the third lens barrel 15 and the helicoid ring 18 with respect to the fixed ring 22 in the optical axis direction are stabilized. That is, it is supported without play in the optical axis direction.

  When the combined body of the third outer cylinder 15 and the helicoid ring 18 is rotated in the extending direction from the wide end, the fitting protrusion 15b (sliding surface 15b-A) and the rotating sliding protrusion 18b (rear sliding surface 18b-D). Moves toward the end of the rotary sliding groove 22d under the guidance of the rotating guide surfaces 22d-A and 22d-B with which they come into contact, and eventually reaches the tele end position shown in FIGS. From the wide end to the telephoto end, the engagement between the fitting protrusion 15b and the rotating sliding protrusion 18b and the rotating sliding groove 22d is maintained, so that the helicoid ring 18 and the third outer cylinder emit light with respect to the fixed ring 22. Axial movement is restricted, and only rotation is performed.

  Further, when the helicoid ring 18 rotates at a fixed position, the cam ring roller 32 is located in the circumferential groove 14e-1 of the roller guide through groove 14e. It rotates at a fixed position without moving in the axial direction. That is, the first lens group LG1 and the second lens group LG2 relatively move in the optical axis direction along a predetermined locus according to the zoom region of the second group guide cam groove 11a and the first group guide cam groove 11b, thereby performing zooming.

  The third outer cylinder 15 and the helicoid ring 18 are further rotated in the extending direction than the tele end, and as shown in FIG. 23 and FIG. 27, when the rotary sliding projection 18b reaches the end of the rotary sliding groove 22d, the third The lens barrel is in a disassembled state in which the outer cylinder 15, the second outer cylinder 13, the first outer cylinder 12, and the like can be pulled forward from the fixed ring 22. However, when the lens barrel stopper 26 is attached to the stopper insertion / removal hole 22e, as shown in FIG. 29, the stopper contact surface 18b-E of one rotation sliding protrusion 18b comes into contact with the lens barrel stopper 26. Since the rotation to the disassembly position is restricted, the lens barrel does not enter the disassembled state unless the lens barrel stopper 26 is removed.

  When the third outer cylinder 15 and the helicoid ring 18 are rotated from the telephoto end in the lens barrel housing direction (downward in FIG. 22), the rotation sliding projection 18b and the fitting projection 15b are skewed in the rotation sliding groove 22d. Move to 22c side. During this time, similarly to the movement from the wide end to the tele end, the fitting projection 15b and the rotary sliding projection 18b are respectively pressed against the opposing rotary guide surfaces 22d-A and 22d-B by the separating direction urging spring 25. The third outer cylinder 15 and the helicoid ring 18 rotate integrally without rattling in the optical axis direction.

  When the rotation in the storage direction is further continued past the wide end position in FIGS. 21 and 25, the end slopes 18b-B of the rotary sliding projections 18b abut the opposing oblique surfaces 22c-B of the oblique grooves 22c. Then, a component force is generated to move the helicoid ring 18 rearward in the optical axis direction along the opposing inclined surface 22c-B. Contrary to the rotation, the helicoid ring 18 moves backward in the optical axis direction while rotating. start. When the helicoid ring 18 moves a little backward in the optical axis direction due to the relationship between the rotary sliding protrusion 18b and the oblique groove 22c, the male helicoid 18a is screwed into the female helicoid 22a again, and thereafter the male helicoid 18a and the female helicoid 22a Due to the screwing relationship, the rotation and storage operation of the helicoid ring 18 is performed until the storage position shown in FIGS. 20 and 24 is reached. The third lens barrel 15 performs the same rotation and storage operation as the helicoid ring 18 by the action of the helicoid ring 18 and the rectilinear guide ring 14, and the fitting projection 15b moves in the oblique groove 22c together with the rotating slide projection 18b. .

  When the rotary slide protrusion 18b moves from the rotary slide groove 22d into the oblique groove 22c, the fitting protrusion 15b and the rotary slide protrusion 18b are in a state in which the position in the optical axis direction is not restricted by the rotary slide groove 22d. Therefore, the position of the third outer cylinder 15 and the helicoid ring 18 in the optical axis direction is loosely fitted to the rectilinear guide ring 14 from the relationship in the photographing state in which the optical axis direction position is strictly determined (FIGS. 32 and 33). Returning to the defined relationship (FIGS. 34 and 35). At this point, since the zoom lens barrel 71 is no longer in the photographing state, the positioning of the third outer cylinder 15 and the helicoid ring 18 in the optical axis direction may not be strict.

  When the helicoid ring 18 and the third lens barrel 15 move rearward in the optical axis direction, the linear guide ring 14 also moves rearward, and the cam ring 11 supported by the linear guide ring 14 also moves rearward. Also, when the helicoid ring 18 switches from the home position rotation to the rotary storage operation, the cam ring roller 32 moves from the circumferential groove portion 14e-1 into the lead groove portion 14e-3, and the cam ring 11 moves to the straight guide ring 14. While rotating with respect to the optical axis, it relatively moves backward in the optical axis direction.

  As described above, in the zoom lens barrel 71 according to the present embodiment, the third outer cylinder 15 that can relatively move the rotating member that performs both the rotation extension (storage) operation and the fixed position rotation operation in the optical axis direction by a small amount. After being divided into the helicoid ring 18, the third outer cylinder 15 and the helicoid ring 18 are urged in the separating direction by the separating direction urging spring 25, and in the photographing state, the rotation sliding protrusion 18 b of the helicoid ring 18 and the third By pressing the fitting projection 15b of the outer cylinder 15 against the opposite end face opposite to the common rotary sliding groove 22d, backlash removal in the optical axis direction with respect to the fixed ring 22 is performed. The rotation slide groove 22d and the rotation slide protrusion 18b constitute a drive mechanism (support mechanism) for selectively giving the helicoid ring 18 a rotation feeding operation and a fixed position rotation operation. By using the part for backlash removal, the number of parts can be reduced.

  Further, since the separation-direction urging spring 25 is held between the third outer cylinder 15 and the helicoid ring 18 that always rotate integrally, an urging member for backlash removal is disposed near the fixed ring 22. No special space is needed to do so. In addition, since the fitting projection 15b is housed in the fitting recess 18e, the space efficiency of the connecting portion between the third outer cylinder 15 and the helicoid ring 18 is excellent.

  The load by the separation-direction urging spring 25 becomes large only at the time of photographing in which both the rotation sliding projection 18b and the fitting projection 15b are engaged with the rotation sliding groove 22d. At the time of non-photographing, the compression degree of the separating direction urging spring 25 is low, so that the sliding resistance in the initial stage of the lens barrel extension is suppressed small, and the durability is excellent.

  As described above, the present invention has been described based on the illustrated embodiment, but the present invention is not limited to this embodiment. For example, in the illustrated embodiment, after extending from the stored state of FIG. 20 to the wide end of FIG. 21, it is possible to zoom further to the tele end of FIG. 22. It can also be applied as a single-focus lens barrel without any modification. Alternatively, even when the helicoid ring 18 and the third outer cylinder 15 are rotated at a fixed position, focusing and the like are performed instead of zooming, the lens barrel can be configured as a single focus lens barrel.

  In the embodiment, the rotational sliding projections 18b, the fitting projections 15b, and the rotational sliding grooves 22d, which are the engagement portions related to the removal of the backlash between the helicoid ring 18 and the third outer cylinder 15, have different positions in the circumferential direction. Although three are provided, the number may be other than three. Further, the urging means for removing backlash is not limited to the form of the three separation-direction urging springs 25 in the embodiment.

  In the embodiment, the rotary sliding projection 18b and the fitting projection 15b provided as protrusions on the helicoid ring 18 and the third outer cylinder 15 are used as sliding contact surfaces, and the rotary sliding projection is formed as a recess on the fixed ring 22 side. The pair of opposed wall surfaces of the groove 22d is a circumferential surface that receives the sliding contact surface. As described above, this structure is preferable because the structure is simplified because the backlash removal structure and the driving mechanism are used in combination. However, the aspect of the sliding contact surface and the circumferential surface in the present invention is not limited to this. For example, a circumferential surface that does not take the form of the opposing wall surface of the groove can be used.

  In the lens barrel of the present invention, the mode of driving the lens group can be different from that of the embodiment. For example, in the embodiment, in addition to the relationship between the helicoid ring 18 and the fixed ring 22, further, between the rectilinear guide ring 14 and the cam ring 11, a rotation feeding operation and a fixed position rotation operation are selected for the cam ring 11. A mechanism (the roller guide through groove 14e and the cam ring roller 32) is provided. As a result, the cam ring 11 is provided with the amount of rotation of the cam ring 11 with respect to the rectilinear guide ring 14 in addition to the amount of rotation of the helicoid ring 18. The amount can be increased. However, the present invention is also applicable to a mode in which the rotary feeding mechanism between the straight guide ring 14 and the cam ring 11 is omitted, and only the feeding amount by the helicoid ring 18 is given to the cam ring 11.

In addition, the present invention can be applied to a rotary feeding device other than a lens barrel by setting the object supported by the rotating ring to something other than an optical element such as a lens frame (lens group).

FIG. 2 is an exploded perspective view of the zoom lens barrel according to the embodiment of the present invention. FIG. 2 is an exploded perspective view of elements related to a support mechanism of a first lens group in the zoom lens barrel in FIG. 1. FIG. 2 is an exploded perspective view of elements related to a support mechanism of a second lens group in the zoom lens barrel in FIG. 1. FIG. 2 is an exploded perspective view of components related to a feeding mechanism from a fixed ring to a cam ring in the zoom lens barrel in FIG. 1. FIG. 2 is a perspective view of a completed state in which a zoom motor and a finder unit are added to the zoom lens barrel of FIG. 1. FIG. 2 is a longitudinal sectional view showing a use state of a camera equipped with a zoom lens barrel to which the present invention is applied, at a wide end and a telephoto end. FIG. 3 is a longitudinal sectional view of the camera in a lens barrel stored state. FIG. 4 is a developed plan view of a fixed ring. FIG. 3 is a developed plan view of a helicoid ring. FIG. 3 is an exploded plan view showing components on the inner peripheral surface side of the helicoid ring in a see-through manner. It is a development top view of the 3rd outer cylinder. FIG. 4 is a developed plan view of a straight guide ring. FIG. 4 is a developed plan view of a cam ring. FIG. 4 is an exploded plan view showing the second group guide cam groove on the inner peripheral surface side of the helicoid ring in a see-through manner. FIG. 4 is a developed plan view of a straight guide ring. FIG. 5 is a developed plan view of a second group lens moving frame. It is a development top view of a 2nd outer cylinder. FIG. 4 is a developed plan view of a first outer cylinder. FIG. 3 is a diagram conceptually illustrating an operation relationship of main components of the zoom lens barrel according to the embodiment. FIG. 10 is a developed plan view showing a relationship between a helicoid ring, a third outer cylinder, and a fixed ring in a lens barrel stored state. FIG. 9 is a developed plan view showing a relationship between a helicoid ring, a third outer cylinder, and a fixed ring at a wide end. FIG. 10 is a developed plan view showing a relationship between a helicoid ring, a third outer cylinder, and a fixed ring at a telephoto end. FIG. 7 is a developed plan view showing a relationship between a helicoid ring, a third outer cylinder, and a fixed ring in a lens barrel disassembled state. FIG. 4 is an exploded plan view of a fixed ring, showing a position of a rotary sliding protrusion of a helicoid ring in a lens barrel stored state. FIG. 4 is an exploded plan view of a fixed ring, showing a position of a rotary sliding protrusion of a helicoid ring at a wide end. FIG. 4 is a developed plan view of a fixed ring, showing a position of a rotary sliding protrusion of a helicoid ring at a tele end. FIG. 4 is an exploded plan view of a fixed ring, showing a position of a rotary sliding protrusion of a helicoid ring in a lens barrel disassembled state. FIG. 26 is a cross-sectional view of the helicoid ring and the fixed ring, taken along the line XXVIII-XXVIII in FIG. 24. It is a perspective view which expands and shows a part of coupling part of a 3rd outer cylinder and a helicoid ring. FIG. 30 is a perspective view of a state where a lens barrel stopper is removed from FIG. 29. FIG. 31 is a perspective view showing a state where the third outer cylinder and the helicoid ring are divided in the optical axis direction from the state of FIG. 30. FIG. 7 is a cross-sectional view illustrating a part of an upper half cross section (wide end) of the photographing state in FIG. 6 in an enlarged manner. FIG. 7 is a cross-sectional view illustrating a part of a lower half cross section (tele end) of the photographing state in FIG. 6 in an enlarged manner. FIG. 8 is an enlarged cross-sectional view showing a part of an upper half cross section of the lens barrel shown in FIG. 7. FIG. 8 is a cross-sectional view showing, on an enlarged scale, a part of a lower half cross section of the lens barrel shown in FIG. 7.

Explanation of reference numerals

LG2 second lens group (optical element, movable lens group)
LG3 Third lens group LG4 Low-pass filter S Shutter A Aperture Z0 Lens barrel center axis (axis, rotation center axis)
Z1 Shooting optical axis Z2 Evacuation optical axis Z3 Optical axis 1 of viewfinder objective system 1 Group lens frame 1a Male adjustment screw 2 Group adjustment ring 2a Female adjustment screw 2b Guide protrusion 2c Engagement claw 1 Group 1 retaining ring 3a Spring receiving section 6 2nd lens frame 8 2nd lens moving frame 8a Straight guide groove 8b Cam follower for second group 8b-1 Front cam follower 8b-2 Back cam follower 10 Second group straight guide ring 10a Crotch protrusion 10b Ring portion 10c Straight guide key 11 Cam ring 11a Second group guide cam groove 11a-1 Front cam groove 11a-2 Rear cam groove 11b First group guide cam groove 11c 11e Circumferential groove 11d Barrier drive ring pressing surface 12 First outer cylinder 12a Engagement protrusion 12b First group adjustment ring guide groove 13 Second outer cylinder 13a Straight guide projection 13b Straight guide groove 13c Inner diameter flange 14 Straight guide ring (straight ring)
14a Linear guide protrusion 14b 14c Relative rotation guide protrusion (rotation guide mechanism)
14d circumferential groove (rotation guide mechanism)
14e Roller guide through groove 14e-1 14e-2 Circumferential groove 14e-3 Lead groove 14f First straight guide groove 14g Second straight guide groove 15 Third outer cylinder (second rotating annular body)
15a Rotation transmitting protrusion 15b Fitting protrusion (second rotation guide protrusion)
15b-A sliding surface (second sliding surface)
15c Spring contact recess 15d Relative rotation guide protrusion (rotation guide mechanism)
15e Circumferential groove (Rotation guide mechanism)
15f Roller fitting groove 17 Roller biasing spring 17a Roller pressing piece 18 Helicoid ring (first rotating ring)
18a Male helicoid (advance / retract mechanism)
18b Rotary slide projection (first rotation guide projection)
18b-A 18b-B End slope 18b-C Front sliding surface 18b-D Rear sliding surface (first sliding contact surface)
18b-E Stopper contact surface 18c Spur gear 18d Rotation transmitting recess 18e Fitting recess 18f Spring insertion recess 18g Circumferential groove (rotation guide mechanism)
21 CCD holder 21a Cam protrusion 22 Fixed ring (annular member)
22a Female helicoid (advance / retract mechanism)
22b Straight guide groove 22c Slant groove 22c-A 22c-B Opposite slant surface 22d Rotating sliding groove (circumferential groove)
22d-A 22d-B Rotary guide surface (circumferential surface)
22e Stopper insertion / removal hole 22z Front annular region 24 1st group urging spring 25 Separating direction urging spring (urging means)
26 lens barrel stopper 28 zoom gear 29 zoom gear shaft 30 finder gear 31 1 group roller (cam follower)
32 Cam Ring Roller (Cam Follower)
32a Roller fixing screw 33 Second group rotation shaft 35 Rotation restricting pin 36 37 Second group lens frame support plate 38 Axial pressing spring 39 Second group lens frame return spring 51 AF lens frame (third group lens frame)
52 53 AF guide shaft 54 AF nut 55 AF frame biasing spring 60 CCD (solid-state image sensor)
61 packing 62 CCD base plate 64 retaining ring fixing screw 66 support plate fixing screw 71 zoom lens barrel 72 camera body 73 filter holder 74 reduction gear box 75 lens drive control FPC board 76 shutter unit 77 exposure control FPC board 80 finder unit 81a objective Window 81b 81c Movable variable lens 81d Prism 81e Eyepiece 81f Eyepiece window 83 84 Holding frame 85 86 Guide shaft 90 Cam gear 101 Barrier cover 102 Barrier pressing plate 103 Barrier drive ring 104 105 Barrier blade 106 Barrier biasing spring 107 With barrier drive ring Spring 140 Control circuit 150 Zoom motor 160 AF motor

Claims (16)

Annular member;
First and second rotating annular bodies supported inside the annular member so as to be relatively movable in the axial direction and to rotate together;
An optical element supported via the first or second rotating annulus;
A pair of circumferential surfaces facing the front and rear in the axial direction formed on the annular member, and a first and a second formed on the first and second rotating annular bodies, respectively, and contacting one and the other of the pair of circumferential surfaces. The first rotating annular body and the second rotating annular body are urged in opposite directions in the axial direction to bring the first and second sliding annular surfaces into contact with the pair of circumferential surfaces. Biasing means for abutting one and the other;
A rotating ring support structure for a lens barrel, comprising: 2. A rotating ring support structure for a lens barrel according to claim 1, wherein said pair of circumferential surfaces are formed as opposed wall surfaces of a circumferential groove formed on an inner circumferential surface of said annular member, and said first and second circumferential surfaces are formed. A sliding ring support structure for a lens barrel, wherein the sliding surface is in contact with one and the other of the opposing wall surfaces of the circumferential groove by the urging means. 3. The rotating ring supporting structure for a lens barrel according to claim 1, wherein said urging means includes at least one spring provided between said first and second rotating annular bodies. Support structure. 4. The lens barrel rotating ring support structure according to claim 3, wherein said biasing means comprises at least one compression coil spring provided between opposed end faces of said first and second rotating annular bodies. Rotating ring support structure. 5. The rotating ring support structure for a lens barrel according to claim 1, wherein the second sliding contact surface is formed in an area overlapping with the first sliding contact surface in a circumferential direction. 6. Rotating ring support structure for the lens barrel. 6. The rotating ring support structure for a lens barrel according to claim 1, wherein the first sliding contact surface is formed by changing a position of the first rotating annular body in a circumferential direction. 7. A rotating ring support structure for a lens barrel formed on a plurality of radial projections. 7. The rotating ring support structure for a lens barrel according to claim 6, wherein three radial projections are provided at substantially equal intervals in the circumferential direction. 8. The rotating ring supporting structure for a lens barrel according to claim 6, wherein the radial projection of the first rotating annular body has a concave portion in the axial direction, and the second sliding contact surface is the concave portion. A rotating ring support structure for the lens barrel formed on the second rotating ring as a projection that can be stored in the lens barrel. 9. The rotating ring support structure for a lens barrel according to claim 1, wherein the first and second rotating annular members move in the axial direction while rotating with respect to the annular member. 10. The first and second sliding contact surfaces can be switched between an advancing / retreating state and a fixed position rotating state in which the rotation does not move in the axial direction at at least one of the front and rear moving ends due to the rotational movement. Is a rotating ring support structure of the lens barrel in contact with a pair of circumferential surfaces. 10. The rotating ring support structure for a lens barrel according to claim 9, wherein a male helicoid and a female helicoid formed on at least one outer peripheral surface of the first and second rotating annular bodies and the inner peripheral surface of the annular member are formed. The male helicoid and the female helicoid are screwed together to provide the rotation advance / retreat operation of the first and second rotating annular bodies, and the male helicoid and the female helicoid are released from the screw engagement in the fixed position rotation state. Rotating ring support structure for lens barrel. 11. The rotating ring support structure for a lens barrel according to claim 10, wherein at least one female helicoid is formed on an inner peripheral surface of the annular member and connected to the peripheral surface in a direction parallel to the female helicoid forming direction. A rotary ring support structure for a lens barrel, wherein a helicoid-free region is formed, and the first and second sliding contact surfaces are positioned corresponding to the helicoid-free region when the helicoid is screwed. 12. The rotating ring support structure for a lens barrel according to claim 11, wherein the first sliding contact surface projects from the outer peripheral surface of the first rotating annular body larger than the male helicoid, and the non-helicoid region is A rotary ring support structure for the lens barrel, wherein the oblique groove is substantially parallel to the female helicoid, and the first sliding contact surface enters the oblique groove when the helicoid is screwed. 13. The rotating ring support structure for a lens barrel according to claim 1, further comprising: a linear ring supported inside the first and second rotary annular members so as to be able to linearly move in the axial direction. A lens having a first and a second rotating annular body respectively rotatably coupled with the rectilinear ring and moving in the axial direction via a rotation guide mechanism which is loosely fitted in the optical axis direction. Rotating ring support structure for the lens barrel. 14. The rotating ring support structure for a lens barrel according to claim 1, wherein the optical element is relatively moved in an optical axis direction by rotation of the first and second rotating annular bodies. 15. Two movable lens groups, wherein when the first and second rotating annular bodies rotate in a state where the first and second sliding contact surfaces are in contact with the pair of circumferential surfaces, the at least two movable lens groups are movable. A rotating ring support structure of a lens barrel in which a magnification operation is performed by relative movement of a lens group in an optical axis direction. First and second rotating annular bodies that are integrally rotatable about a rotation center axis parallel to the optical axis and relatively movable in the optical axis direction;
An optical element that advances and retreats in the optical axis direction by rotation of the first and second rotating annular bodies;
A non-rotating annular member that supports the first and second rotating annular members inside;
Between the annular member and the first and second rotating annular bodies, between the moving ends of the first and second rotating annular bodies when the first and second rotating annular bodies are rotated in the optical axis direction. Advance / retreat mechanism to advance / retreat with;
A circumferential groove formed on the inner peripheral surface of the annular member;
It is provided on the outer peripheral surface of the first and second rotating annular bodies, and when the first and second rotating annular bodies are moved to at least one of the front and rear moving ends in the optical axis direction by the advance / retreat mechanism, the circumferential grooves are formed. First and second rotation guide projections that engage to rotate the first and second rotating annular bodies at a fixed position without moving in the optical axis direction;
Biasing means for biasing the first and second rotating annular bodies in a direction away from each other, and pressing the first and second rotating guide projections against opposed wall surfaces of the circumferential groove;
A rotating ring support structure for a lens barrel, comprising: First and second rotating annular bodies that are integrally rotatable about an axis and relatively movable in a direction along the axis;
A non-rotating annular member that supports the first and second rotating annular members inside;
The annular member is provided between the first and second rotating annular bodies, and when the first and second rotating annular bodies are rotated, between the front and rear moving ends in the axial direction with respect to the annular member. Advance / retreat mechanism to advance / retreat with;
A circumferential groove formed on the inner peripheral surface of the annular member;
It is provided on the outer peripheral surface of the first and second rotating annular bodies, and when the first and second rotating annular bodies are moved to at least one of the front and rear moving ends in the axial direction by the advance / retreat mechanism, the circumferential grooves are formed. First and second rotation guide projections for engaging and rotating the first and second rotating annular bodies in a fixed position without moving in the axial direction;
Biasing means for biasing the first and second rotating annular bodies in a direction away from each other, and pressing the first and second rotating guide projections against opposed wall surfaces of the circumferential groove;
A rotating ring support structure comprising:

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