JP4598106B2 - Zoom lens barrel - Google Patents

Description

  The present invention relates to a zoom lens barrel in which movement between a storage position where no photographing is performed and a maximum extension position where photographing is performed is performed by a small (thin) mechanism.

  In a zoom lens barrel of a compact camera, the storage length is made as thin as possible in the retracted (collapsed) state to make it compact. On the other hand, in order to achieve a high zoom ratio, the lens barrel member that holds the lens group in the shooting state It is required to increase the amount of feeding forward in the optical axis direction. However, shortening the storage length means that the length in the optical axis direction of each member constituting the zoom lens barrel is inevitably shortened, so the reduction in thickness during storage and the increase in the amount of extension during shooting are a trade-off. It was a serious request.

US 2002 / 044363A1 Publication

  SUMMARY OF THE INVENTION An object of the present invention is to provide a zoom lens barrel that has a short extension in the optical axis direction when retracted and a large amount of extension that can increase the length in the optical axis direction in a shooting state.

  In the present invention, the shortening of the storage length and the securing (maximization) of the feeding amount are both achieved by the three-stage feeding zoom lens barrel.

  The zoom lens barrel according to the present invention has a fixed ring: a moving end that moves in the optical axis direction while rotating between moving ends that are respectively defined in front and rear in the optical axis direction with respect to the fixed ring. A first rotating ring that rotates at a fixed position in the direction of movement in the optical axis direction while rotating between moving ends respectively defined before and after the optical axis direction with respect to the first rotating ring, and moving forward in the optical axis direction A second rotating ring that rotates at a fixed position at the end; and a first outer cylinder that advances and retreats in the optical axis direction with respect to the second rotating ring by rotation accompanied by movement of the second rotating ring in the optical axis direction; The movement between the storage position and the maximum extension position of the zooming region is performed by rotation accompanied by movement in the optical axis direction between the movement ends of the first rotation ring and the second rotation ring before and after the optical axis direction, Magnification by the fixed position rotation at the forward moving end of each of the first rotating ring and the second rotating ring It is characterized in that the run.

  The maximum extension position of the zooming area is preferably set to the wide end in a lens system generally employed in a digital compact camera.

  The second rotating ring can be rotated by the rotational force of the first rotating ring.

  The first outer ring is provided with a third outer cylinder that moves together in the optical axis direction, and the second outer ring is provided with a second outer cylinder that moves together in the optical axis direction. The outer cylinder, the second outer cylinder, and the third outer cylinder are preferably positioned in this order from the inner diameter side to the outer diameter side.

  Since the zoom lens barrel of the present invention is extended in three stages, it is possible to achieve both shortening of the storage length and securing (maximization) of the extension amount.

[Overall description of lens barrel]
The overall structure of the zoom lens barrel 71 of this 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 has a first lens group LG1, a shutter S and an aperture A, and a second lens in order from the object side. It 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 this photographing optical system is indicated by Z1. The photographic optical axis Z1 is parallel to the rotation center axis (hereinafter referred to as the lens barrel center axis Z0) of each annular member constituting the appearance of the zoom lens barrel 71, and is lower than the lens barrel center axis Z0. Eccentric. Zooming is performed by moving the first lens group LG1 and the second lens group LG2 back and forth along the photographing optical axis Z1 along a predetermined locus, and focusing is performed by moving the third lens group LG3 in the same direction. In the following description, “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 part of the fixed ring 22. A CCD 60 is supported on the CCD holder 21 via a CCD base plate 62, and a low pass filter LG 4 is supported at the 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. At the rear of the CCD holder 21, an LCD 20 for displaying images and shooting information is provided.

  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 linearly movable in the optical axis direction. That is, the front end portion and the rear end portion of a pair of AF guide shafts 52 and 53 parallel to the photographing optical axis Z 1 are fixed to the fixed ring 22 and the CCD holder 21, respectively. The guide holes 51a and 51b formed in the AF lens frame 51 are slidably fitted. In this 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 guide shaft (giving strict accuracy), and the AF guide shaft 53 is a sub (non-rotating) guide shaft. An AF nut 54 is screwed with 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 is slidable with respect to the guide groove 51m. It fits in. The AF lens frame 51 further includes a stopper protrusion 51n positioned behind the AF nut 54. The AF lens frame 51 is urged forward by an AF frame urging spring 55, and the forward moving end of the AF lens frame 51 is determined by the stopper projection 51 n coming into contact with 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 moved rearward. With the above structure, when the drive shaft of the AF motor 160 is rotated forward and backward, the AF lens frame 51 is advanced and retracted in the optical axis direction. It is also possible to press the AF lens frame 51 directly (without using the AF nut 54) and move it backward against the AF frame biasing spring 55.

  As shown in FIG. 5, a zoom motor 150 and a reduction gear box 74 are supported on the upper portion of the fixed ring 22. The reduction gear box 74 has a reduction gear train inside, 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, there are a female helicoid 22a, three rectilinear guide grooves 22b parallel to the photographing optical axis Z1, three skew grooves 22c parallel to the female helicoid 22a, and each skew groove 22c. A circumferential sliding groove 22d communicating with the front end is formed. The rotary sliding groove 22d is formed in the vicinity of the front end portion of the stationary 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 rotational sliding protrusion 18b positioned in the skew groove 22c and the rotational 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 to 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 in a state where the female helicoid 22a and the male helicoid 18a are in a screwed relationship, and to some extent forward. When moved, the male helicoid 18a is disengaged from the female helicoid 22a, and only the circumferential rotation about the lens barrel central axis Z0 is performed by the engagement relationship between the rotational sliding groove 22d and the rotational sliding protrusion 18b.

  The oblique groove 22c is a relief groove formed to avoid interference between the rotary sliding protrusion 18b and the fixed ring 22 when the female helicoid 22a and the male helicoid 18a are screwed together. 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 peaks sandwiching each skew groove 22c is wider than the circumferential interval between other helicoid peaks, and the male helicoid 18a is a helicoid mountain with a wide circumferential interval. In order to engage, the three helicoid peaks 18a-W located behind the rotary sliding protrusion 18b are wider in the circumferential direction than the other helicoid peaks.

  The stationary ring 22 is further formed with a stopper insertion / removal hole 22e penetrating the outer peripheral surface and the rotational sliding groove 22d, and the rotation of the helicoid ring 18 beyond the imaging region is restricted with respect to the stopper insertion / removal hole 22e. The disassembly stopper 26 for this is detachable.

  A rotation transmission projection 15a (FIG. 11) projecting rearward from the rear end of the third outer cylinder 15 is fitted into a rotation transmission recess 18d (FIGS. 4 and 10) formed on the inner peripheral surface of the front end portion of the helicoid ring 18. Has been. The rotation transmission recesses 18d and the rotation transmission projections 15a are provided at three positions with different positions in the circumferential direction, and the rotation transmission projections 15a and the rotation transmission recesses 18d corresponding to the circumferential positions correspond to the central axis of the lens barrel. Relative sliding in the direction along Z0 is possible and coupled in a circumferential direction around the lens barrel central axis Z0 so that relative rotation is impossible. 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 notching a partial area on the inner diameter side of the rotary sliding projection 18b, and the fitting projection 15b fitted into the fitting recess 18e is rotated. When the sliding protrusion 18b engages with the rotational sliding groove 22d, it simultaneously engages with the rotational 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 that bias each other in the separation direction in the optical axis direction. The separating-direction biasing spring 25 is a compression coil spring, and its rear end is housed in a spring insertion recess 18 f that opens at the front end of the helicoid ring 18, and its front end abuts against the spring contact recess 15 c of the third outer cylinder 15. It touches. The separation direction biasing spring 25 presses the fitting projection 15b toward the front side wall surface of the rotary sliding groove 22d and presses the rotary sliding projection 18b toward the rear side wall surface of the rotary sliding groove 22d. Thus, the backlash in the optical axis direction of the third outer cylinder 15 and the helicoid ring 18 with respect to the fixed ring 22 is removed.

  On the inner peripheral surface of the third outer cylinder 15, a relative rotation guide protrusion 15d projecting in the inner diameter direction, a circumferential groove 15e centering on the lens barrel central axis Z0, and 3 parallel to the photographing optical axis Z1 are provided. A 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 transmission protrusion 15a, and a rear end portion thereof is opened rearward through the rotation transmission protrusion 15a. Further, a circumferential groove 18g centering on the lens barrel central axis Z0 is formed on the inner peripheral surface of the helicoid ring 18 (FIGS. 4 and 10). A rectilinear 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 rectilinear guide ring 14, three rectilinear guide protrusions 14a projecting in the outer diameter direction in order from the rear in the optical axis direction, and a plurality of relative rotation guide protrusions 14b provided in different positions in the circumferential direction, respectively. 14c and a circumferential groove 14d centering on the lens barrel central axis Z0 are formed (FIGS. 4 and 12). The rectilinear guide ring 14 is guided linearly in the optical axis direction with respect to the fixed ring 22 by engaging the rectilinear guide protrusion 14a with the rectilinear guide groove 22b. In addition, the third outer cylinder 15 has a circumferential groove 15e engaged with the relative rotation guide protrusion 14c and a relative rotation guide protrusion 15d engaged with the circumferential groove 14d, so that the third outer cylinder 15 is relative to the rectilinear guide ring 14. It is coupled to be rotatable. The circumferential groove 15e and the relative rotation guide projection 14c, and the circumferential groove 14d and the relative rotation guide projection 15d are loosely fitted so as to be slightly movable in the optical axis direction. Further, the helicoid ring 18 is also coupled to the linear guide ring 14 so as to be relatively rotatable 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 relatively movable 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 roller guide through-groove 14e has circumferential front and rear circumferential groove portions 14e-1 and 14e-2 formed in the circumferential direction, and both circumferential groove portions 14e-1 and 14e-2. And a lead groove 14e-3 for connecting the two. 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 roller 32 is fixed to the cam ring 11 via a roller fixing screw 32a, and is provided with three different positions in the circumferential direction. The cam ring roller 32 further passes through the roller guide through groove 14e and is fitted into the roller fitting groove 15f on the inner peripheral surface of the third outer cylinder 15. Three roller pressing pieces 17a provided on the roller biasing spring 17 are fitted in the vicinity of the front end portion of each roller fitting groove 15f (FIG. 11). When the cam ring roller 32 engages with the circumferential groove portion 14e-1, the roller pressing piece 17a abuts against the cam ring roller 32 and presses backward, and the cam ring roller 32 and the roller guide through groove 14e (circumferential direction) Take backlash with the groove 14e-1).

  From the above structure, the mode of extension from the fixed ring 22 to the cam ring 11 is understood. In other words, when the zoom gear 28 is rotationally driven in the lens barrel feeding direction by the zoom motor 150, the helicoid ring 18 is fed 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 rotatable and rotatable relative to the linear guide ring 14 by the engagement relationship between the circumferential grooves 14d, 15e and 18g and the relative rotation guide protrusions 15d, 14c and 14b, respectively. Since they are coupled so as to move in the axial direction (the direction along the lens barrel central axis Z0), when the helicoid ring 18 is rotated out, the third outer cylinder 15 is also extended forward while rotating in the same direction. Accordingly, the rectilinear guide ring 14 moves straight forward together with the helicoid ring 18 and the third outer cylinder 15. Further, the rotational force of the third outer cylinder 15 is transmitted to the cam ring 11 via the roller fitting groove 15 f and the cam ring roller 32. Since the cam ring roller 32 is also fitted in the roller guide through groove 14e, the cam ring 11 is extended forward with respect to the linear guide ring 14 while rotating according to the shape of the lead groove 14e-3. As described above, the rectilinear guide ring 14 itself also moves straight forward together with the third outer cylinder 15 and the helicoid ring 18, and as a result, the cam ring 11 has a rotational advance according to the lead groove portion 14 e-3 and a rectilinear guide. An amount of movement in the optical axis direction is added to the amount of linear movement of the ring 14 forward.

  The above-described feeding operation is performed while the male helicoid 18a and the female helicoid 22a are screwed together. At this time, the rotary sliding protrusion 18b moves in the oblique groove 22c. When the helicoid ring 18 is fed out by a predetermined amount, the screw engagement between the male helicoid 18a and the female helicoid 22a is released, and the rotating sliding protrusion 18b eventually enters the rotating sliding groove 22d from the skew groove 22c. Then, since the rotational output by the helicoid does not act, the helicoid ring 18 and the third outer cylinder 15 only rotate at a fixed position in the optical axis direction due to the engagement relationship between the rotational sliding protrusion 18b and the rotational sliding groove 22d. To do. The cam ring roller 32 enters the circumferential groove 14e-1 of the penetrating guide groove 14e almost simultaneously with the rotation sliding protrusion 18b entering the rotation sliding groove 22d from the skew groove 22c. 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 rotationally driven in the lens barrel storage direction, the reverse operation is performed. When the helicoid ring 18 is rotated until the cam ring roller 32 enters the circumferential groove portion 14e-2 of the roller guide through groove 14e, each of the above-described lens barrel members retracts to the position shown in FIG.

  Subsequently, the structure ahead of 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 in different positions in the circumferential direction. . The first rectilinear guide groove 14f is composed of a pair of grooves located on both sides of the three second rectilinear guide grooves 14g out of the six, and the second group rectilinear guide ring 10 is in relation to the three first rectilinear guide grooves 14f. Three crotch-shaped projections 10a (FIGS. 3 and 15) provided in the slidably engage with each other. On the other hand, six rectilinear guide protrusions 13a (FIGS. 2 and 17) projecting from the outer peripheral surface of the rear end portion of the second outer cylinder 13 are slidably engaged with the second rectilinear guide groove 14g. Yes. Therefore, both the second outer cylinder 13 and the second group rectilinear guide ring 10 are guided in the straight direction in the optical axis direction via the rectilinear guide ring 14.

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

  First, the support structure of the second lens group LG2 will be described. The second group rectilinear guide ring 10 has three rectilinear guide keys 10c projecting forward from a ring portion 10b connecting the three crotch protrusions 10a (FIGS. 3 and 15). As shown in FIGS. 6 and 7, the outer edge portion of the ring portion 10b can rotate relative to the circumferential groove 11e formed on the inner peripheral surface of the rear end portion of the cam ring 11, and cannot move relative to the optical axis. The linear guide key 10 c is engaged and extends inside the cam ring 11. Each rectilinear guide key 10c has a pair of guide surfaces parallel to the photographic optical axis Z1 on its side surface, and these guide surfaces are rectilinear guide grooves of the second group lens moving frame 8 supported inside the cam ring 11. By engaging with 8a, the second group lens moving frame 8 is guided straight in the axial direction. 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 rectilinear guide ring 10 is provided with three rectilinear guide keys 10c at different positions in the circumferential direction. One of the rectilinear guide keys 10c-W is an exposure control FPC (flexible flexible) described later. Printed circuit) In order to serve also as a support member for the substrate 77, it is wider in the circumferential direction than the remaining two linear guide keys 10c. The wide straight guide key 10c-W is formed with a PWB through hole 10d that is partly cut out in the vicinity of the connection portion with the ring portion 10b and penetrates in the radial direction. As shown in FIG. The flexible PWB 77 extends from the rear of the ring portion 10b through the PWB through hole 10d to the outer peripheral surface side of the rectilinear guide key 10c-W, and is bent rearward at the tip of the rectilinear guide key 10c-W. Correspondingly, one of the three rectilinear guide grooves 8a is a wide rectilinear guide groove 8a-W with which a wide rectilinear guide key 10c-W can be engaged. The central portion of the rectilinear guide groove 8a-W is a penetrating portion through which the flexible PWB 77 for exposure control can pass, and a bottomed portion for supporting the rectilinear guide key 10c-W is provided on both sides of the penetrating portion. Is formed. On the other hand, the remaining two rectilinear guide grooves 8 a are 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 rectilinear guide ring 10 can be combined only at a specific rotational phase in which the rectilinear guide key 10c-W can be engaged with the rectilinear guide groove 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 is composed of 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. Both the front cam groove 11a-1 and the rear cam groove 11a-2 are cam grooves formed by tracing the basic trajectory α of the same shape, but each does not cover the entire area of the basic trajectory α. The front cam groove 11a-1 and the rear cam groove 11a-2 are different from each other in the area occupied on the basic locus α. The basic trajectory is a conceptual cam groove shape including all lens barrel use areas (use areas) including a zoom area and a storage area, and an assembly / disassembly area of the lens barrel. In other words, the lens barrel use area is an area in which the movement of the second group lens moving frame 8 can be controlled by the cam groove shape, and is used to distinguish from the assembly / disassembly area. The zoom area is an area for controlling the movement between the wide end and the tele end in the lens barrel use area, and is used to distinguish it from the storage area. When the cam ring 11 includes a pair of the front cam groove 11a-1 and the rear cam groove 11a-2, three groups of two-group guide cam grooves 11a are formed at equal intervals in the circumferential direction.

  A 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. Similar to the second group guide cam groove 11a, the second group cam follower 8b is also equally spaced in the circumferential direction with a pair of front cam follower 8b-1 and rear cam follower 8b-2 having different positions in the optical axis direction and circumferential direction as one group. The front cam followers 8b-1 are engaged with the front cam grooves 11a-1, and the rear cam followers 8b-2 are engaged 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 linearly guided 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 becomes light according to the second group guide cam groove 11a. Move in the axial direction with a predetermined trajectory.

  Inside the second group lens moving frame 8, a second group lens frame 6 holding the second lens group LG2 is supported. The second group lens frame 6 is pivotally supported via a second group rotation shaft 33 with respect to a pair of second group lens frame support plates 36 and 37, and the second group frame support plates 36 and 37 are supported by a support plate fixing screw 66. Is fixed to the second group lens moving frame 8. The second group rotation shaft 33 is parallel to the photographing optical axis Z1 and is eccentric with respect to the photographing optical axis Z1, and the second group lens frame 6 has the second group rotation shaft 33 as the rotation center, and the second lens group LG2. And a retracting position for storage (FIG. 6) for displacing the optical axis of the second lens group LG2 from the photographing optical axis Z1 to the retracting optical axis Z2. 7). The second group lens moving frame 8 is provided with a rotation restricting pin 35 that restricts 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 return spring 39. It is urged to rotate in the contact direction with the rotation regulating pin 35. The axial pressing spring 38 performs backlash removal in the optical axis direction of the second group lens frame 6.

  The second group lens frame 6 moves integrally with the second group lens moving frame 8 in the optical axis direction. The CCD holder 21 has a cam projection 21a (FIG. 4) projecting forward at a position engageable with the second group lens frame 6, and the second group lens moving frame 8 is arranged in the storing direction 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 group lens frame 6 and rotates to the above retracted position.

  Next, a support structure for the first lens group LG1 will be described. Three rectilinear guide grooves 13b are formed in the optical axis direction on the inner peripheral surface of the second outer cylinder 13 that is guided linearly in the optical axis direction via the rectilinear guide ring 14. In addition, three engagement protrusions 12a formed on the outer peripheral surface near the rear end portion of the first outer cylinder 12 are slidably fitted in each of the straight guide grooves 13b (FIGS. 2, 17, and 18). reference). That is, the first outer cylinder 12 is guided in a straight line 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 diameter flange 13 c directed in the circumferential direction on the inner peripheral surface near the rear end portion, and the inner diameter flange 13 c slides in a circumferential groove 11 c provided on the outer peripheral surface of the cam ring 11. By engaging with each other, the second outer cylinder 13 is coupled to the cam ring 11 so as to be rotatable relative to the cam ring 11 but not movable relative to the optical axis. On the other hand, the first outer cylinder 12 has three first group rollers (cam followers) 31 projecting in the inner diameter direction, and each of the first group rollers 31 is formed on the outer peripheral surface of the cam ring 11. The guide cam groove 11b is slidably fitted.

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

  The first group adjusting ring 2 has a pair of guide protrusions 2b (only one is shown in FIG. 2) protruding in the outer diameter direction, and the pair of guide protrusions 2b is on the inner peripheral surface side of the first outer cylinder 12. Are slidably engaged with a pair of first-group adjustment ring guide grooves 12b. The first group adjustment ring guide groove 12b is formed in parallel with the photographic optical axis Z1, and the first group adjustment ring 2 and the first group lens frame 1 are arranged according to 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. Further, the first group retaining ring 3 is fixed to the first outer cylinder 12 by a retaining ring fixing screw 64 so as to block the front of the guide protrusion 2b. Between the spring receiving portion 3a of the first group retaining ring 3 and the guide projection 2b, a first group biasing spring 24 made of a compression coil spring is provided, and the first group adjusting ring 2 causes the first group adjusting ring 2 to light. It is biased axially rearward. The first group adjusting ring 2 is engaged with the front surface of the first group retaining ring 3 (the surface on the side visible in FIG. 2) by engaging an engaging claw 2c projecting on the outer peripheral surface near the front end thereof. The maximum position of the rearward movement in the optical axis direction relative to the outer cylinder 12 is regulated (see the upper half section in FIG. 6). On the other hand, by compressing the first group biasing 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 on the inner side of the second group lens moving frame 8, and the air distance between the shutter S and the aperture stop A between the second lens group LG2 is fixed. Two actuators 131 and 132 (FIG. 19) for driving the shutter S and the diaphragm A are arranged one by one at the front and rear positions with the shutter unit 76 interposed therebetween. An exposure control FPC board 77 for connecting to the control circuit 140 is extended. Note that the exposure control flexible FPC 77 does not actually exist at the position of the lower half cross 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 to close the photographing aperture and protect the photographing optical system (first lens group LG1) when not photographing. The lens barrier mechanism includes a pair of barrier blades 104 and 105 that are rotatable about a rotation shaft provided at a position eccentric with respect to the lens barrel central axis Z0, and urges the barrier blades 104 and 105 in the closing direction. A pair of barrier urging springs 106, a barrier drive ring 103 that can be rotated about the central axis Z0 of the barrel, and engage with the barrier blades 104 and 105 by rotation in a predetermined direction, and the barrier drive ring 103 A barrier drive ring biasing spring 107 that biases 103 in the barrier opening direction and a barrier pressing plate 102 positioned between the barrier blades 104 and 105 and the barrier drive ring 103 are provided. The urging force of the barrier drive ring urging spring 107 is set to be 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 is attached. The biasing spring 107 holds the barrier driving ring 103 at the angular position for opening the barrier, and the barrier blades 104 and 105 are opened against the barrier biasing spring 106. During the movement of the zoom lens barrel 71 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 opposes the barrier drive ring 103 in the barrier opening direction. The barrier driving ring 103 is disengaged from the barrier blades 104 and 105, and the barrier blades 104 and 105 are closed by the biasing force of the barrier biasing spring 106. The front part of the lens barrier mechanism is covered with a barrier cover 101 (decorative plate).

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

  Since the cam ring 11 has already been described up to the stage where the cam ring 11 is extended from the storage position to the fixed position rotation state, a brief description will be given. 7, the zoom lens barrel 71 is completely stored in the camera body 72, and the front surface of the camera 70 is flat so that the zoom lens barrel 71 does not protrude. When the zoom gear 28 is driven to rotate in the extending direction by the zoom motor 150 from the lens barrel storage state, the combined body of the helicoid ring 18 and the third outer cylinder 15 is rotated and extended according to the helicoid (male helicoid 18a, 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 is a lead structure (cam ring roller) provided between the linear movement of the linear guide ring 14 and the linear guide ring 14. 32, the combined movement with the feeding portion by the lead groove 14e-3) is performed. When the helicoid ring 18 and the cam ring 11 are drawn out to a predetermined position in front, the functions of the respective rotary feeding structures (helicoid, lead) are canceled and only the circumferential rotation about the lens barrel central axis Z0 is performed. become.

  When the cam ring 11 rotates, on the inner side, the second group lens moving frame 8 guided linearly through the second group linear guide ring 10 is in the optical axis direction due to the relationship between the second group cam follower 8b and the second group guide cam groove 11a. Is moved along a predetermined trajectory. 7, the second group lens frame 6 in the second group lens moving frame 8 is stored in the retracted position for decentering upward from the photographing optical axis Z1 by the action of the cam projection 21a protruding from the CCD holder 21. The second lens group LG2 was at the retracted optical axis Z2 position. The second group lens frame 6 is separated from the cam projection 21a while the second group lens moving frame 8 is extended to the zoom region, and the optical axis of the second lens group LG2 is adjusted by the urging force of the second group lens frame return spring 39. It is rotated to a photographing position (FIG. 6) that coincides 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 again to the storage position.

  Further, when the cam ring 11 rotates, the first outer cylinder 12 guided linearly through the second outer cylinder 13 on the outside of the cam ring 11 is related to the first group roller 31 and the first group guide cam groove 11b. Is moved along a predetermined locus in the optical axis direction.

  That is, the first lens group LG1 and the second lens group LG2 are extended with respect to the imaging surface (CCD light receiving surface), respectively, with the former moving amount of the cam ring 11 with respect to the fixed ring 22 and the first moving position with respect to the cam ring 11. It is determined as a sum of the cam feed amount of the outer cylinder 12 and the latter is a sum of the amount of forward movement of the cam ring 11 relative to the fixed ring 22 and the cam feed amount of the second group lens moving frame 8 relative to the cam ring 11. Determined. 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 interval between them. When the lens barrel is extended from the storage position of FIG. 7, first, the wide end extended state shown in the lower half cross section of FIG. 6 is obtained, and when the zoom motor 150 is further driven in the lens barrel extending direction, the upper half cross section of FIG. As shown in FIG. As can be seen from FIG. 6, in the zoom lens barrel 71 of the present embodiment, the distance between the first lens group LG1 and the second lens group LG2 is large at the wide end, and the first lens group LG1 and the second lens at the tele end. The group LG2 moves in the direction of mutual approach, and the interval is reduced. 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-mentioned 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 opposite to that at the time of the above-described extension, so that the storage position is completely stored in the camera body 72 (FIG. 7). Moved to. In the middle of the movement to the storage position, the second group lens frame 6 is rotated to the storage retreat position by the cam projection 21 a 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 as the third lens group LG3 and the low-pass filter LG4 in the optical axis direction (overlapping in the radial direction of the lens barrel). . Due to the retracting structure of the second lens group LG2 during storage, the storage length of the zoom lens barrel 71 is shortened, and the thickness of the camera body 72 in the left-right direction in FIG. 7 can be reduced.

  The digital camera 70 includes a zoom finder that operates in conjunction with the zoom lens barrel 71. The zoom finder meshes the finder gear 30 with the spar gear portion 18c to obtain power from the helicoid ring 18. When the helicoid ring 18 rotates at the above-mentioned fixed position in the zoom region, the finder gear receives the rotational force. 30 rotates. The finder optical system includes an objective window 81a, a first movable variable lens 81b, a second movable variable lens 81c, a prism 81d, an eyepiece lens 81e, and an eyepiece window 81f, and first and second movable variable magnifications. 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 zoom lenses 81b and 81c are guided in a straight line so as to be movable in the direction of the optical axis Z3 by guide shafts 85 and 86 (which appear to be overlapped in FIGS. 6 and 7), and A moving force is applied by a cam gear 90 (FIG. 5) that can be rotated 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 variable magnification lenses 81b and 81c advance and retract. The above components of the zoom finder are sub-assembled as a finder unit 80 shown in FIG.

[Description of Features of the Present Invention]
As described above, in the zoom lens barrel 71, the helicoid ring 18 (first rotating ring) and the third outer cylinder 15 are in the middle from the lens barrel storage state of FIG. 7 to the use state (zoom region) of FIG. The (first rotating ring) and the cam ring 11 (second rotating ring) are rotated forward, and the helicoid ring 18, the third outer cylinder 15, and the cam ring 11 are moved in the optical axis direction in use. Rotate in place. As described above, this operation of the cam ring 11 involves the helicoid ring 18 and the stationary ring (annular member) 22, and the operation mode of the helicoid ring 18 with respect to the stationary ring 22 will be described with reference to FIGS. 20 to 29. explain.

  As shown in FIGS. 24 to 28, three skew grooves (non-helicoid regions) 22c formed on the inner circumferential surface of the fixed ring 22 are each paired with a pair of opposed skew surfaces 22c- facing each other in the circumferential direction. A, 22c-B, and the three rotating sliding protrusions (rotating guide protrusions) 18b of the helicoid ring 18 are respectively a pair of circumferential surfaces 18b-A facing the opposing oblique surfaces 22c-A, 22c-B. , 18b-B. Opposing oblique surfaces 22c-A and 22c-B of the oblique groove 22c are formed in a direction parallel to the helicoid mountain of the female helicoid (advance / retreat mechanism) 22a, and the circumferential surface 18b of the rotational sliding projection 18b. -A and 18b-B have shapes that do not interfere with the opposing oblique surfaces 22c-A and 22c-B. Specifically, as shown in FIG. 28, when the male helicoid 18a and the female helicoid (advance / retreat mechanism) 22a are screwed together, the opposing oblique surfaces 22c-A and 22c-B of the oblique groove 22c are rotationally sliding projections. The circumferential surfaces 18b-A and 18b-B of 18b are not clamped (engaged). In order to make only one rotation sliding protrusion 18b contact the lens barrel stopper 26, a part of the circumferential surface 18b-A is cut out to form a stopper contact surface 18b-E parallel to the optical axis. Has been.

  Each of the three rotational sliding grooves (circumferential grooves) 22d following the skew groove 22c has a pair of parallel rotation guide surfaces 22d-A and 22d-B that are spaced apart from each other in the optical axis direction, and have a helicoid ring. The three rotation sliding protrusions 18b on the 18 side respectively have a front sliding surface 18b-C and a rear sliding surface 18b-D that can be slidably contacted with the rotation guide surfaces 22d-A and 22d-B.

  20 and 24, the rotational sliding protrusion 18b of the helicoid ring 18 is located in the skew groove 22c of the stationary ring 22, and the circumferential surfaces 18b-A and 18b-B are respectively provided. Opposite oblique surfaces 22c-A and 22c-B are opposed to each other in a slightly spaced state. In the lens barrel storage state, the male helicoid 18a and the female helicoid 22a are in a screwed state. Accordingly, when the zoom gear (drive gear) 28 meshed with the spur gear portion (peripheral gear portion) 18c gives the helicoid ring 18 rotation in the lens barrel feeding direction (upper direction in FIG. 20), the helicoid ring 18 is separated from the male helicoid 18a. It moves forward in the optical axis direction (left side in the figure) due to the relationship of the female helicoid 22a. When the helicoid ring 18 is rotated, the rotary sliding protrusion 18b moves in the skew groove 22c, so that the rotary sliding protrusion 18b does not interfere with the female helicoid 22a of the stationary ring 22.

  As described above, when the helicoid ring 18 moves forward in the optical axis direction, the linear guide ring 14 is also moved forward together with the helicoid ring 18 in the optical axis direction due to the engagement relationship between the circumferential groove 18g and the relative rotation guide protrusion 14b. The cam ring 11 supported by the rectilinear guide ring 14 is also given forward movement. Further, the rotational force of the helicoid ring 18 is transmitted to the cam ring 11 via the third outer cylinder 15, and the cam ring 11 depends on the relationship between the lead groove portion 14e-3 of the roller guide through groove 14e and the cam ring roller 32. The linear guide ring 14 is fed forward in the optical axis direction. Further, when the cam ring 11 rotates, the first lens group (optical element, movable lens group) LG1 and the second lens group (optical) according to the first group guide cam groove 11b and the second group guide cam groove 11a formed in the cam ring 11. Element, movable lens group) LG2 moves relative to the optical axis along a predetermined locus.

  When the rotational sliding projection 18b moves to the forefront portion of the skew groove 22c, the rotational slide protrusion 18b is detached from the skew groove 22c and enters the rotational sliding groove 22d. The male helicoid 18a and the female helicoid 22a have a formation region in the optical axis direction so as to release the mutual screwing at this time. Specifically, on the inner peripheral surface of the fixed ring 22, the region where the rotational sliding groove 22d is formed 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 so as to be larger than the formation region 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 is engaged with the rotary sliding groove 22d, the rear male helicoid 18a is positioned (overlapped) 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 rotating / sliding protrusion 18b engages with the rotating / sliding groove 22d, the male helicoid 18a and the female helicoid 22a are unscrewed, and a repetitive output in the optical axis direction acts on the rotating helicoid ring 18. No longer. Thereafter, the helicoid ring 18 only rotates in the circumferential direction in accordance with the rotation of the zoom gear 28 in the lens barrel feeding direction. As shown in FIG. 21, the zoom gear 28 maintains meshing with the spar gear portion 18c even after the helicoid ring 18 is rotated to a fixed position, and continuously rotates the helicoid ring 18 when the rotation is extended. Can do.

  The state shown in FIGS. 21 and 25 in which the helicoid ring 18 rotates at a fixed position and the rotational sliding protrusion 18b slightly advances in the rotational sliding groove 22d is the wide end of the zoom lens barrel 71. As shown in FIG. 25, at the wide end, the parallel front sliding surface 18b-C and the rear sliding surface 18b-D forming the front and rear ends of the rotary sliding protrusion 18b are rotated in the front and rear directions of the rotary sliding groove 22d. Since the helicoid ring 18 is sandwiched between the guide surfaces 22d-A and 22d-B, the movement of the helicoid ring 18 in the optical axis direction is restricted.

  When the rotary slide protrusion 18b moves into the rotary slide groove 22d, the fitting protrusion 15b located at the same circumferential position as the rotary slide protrusion 18b is simultaneously accommodated in the rotary slide groove 22d, and the separation biasing spring 25 By the urging force, the fitting projection 15b is pressed against the front rotation guide surface 22d-A, and the rear sliding surface 18b-D of the rotation sliding projection 18b is pressed against the rear rotation guide surface 22d-B (see FIG. 29). ). When the combined body of the third outer cylinder 15 and the helicoid ring 18 is rotated in the feeding direction from the wide end, the fitting protrusion 15b and the rotational sliding protrusion 18b (rear sliding surface 18b-D) come into contact with each other. The guides of the rotation guide surfaces 22d-A and 22d-B are received and moved toward the terminal end of the rotary slide groove 22d, and eventually reach the tele end position shown in FIGS. Between the wide end and the tele end, the engagement of the fitting protrusion 15b, the rotation sliding protrusion 18b, and the rotation sliding groove 22d is maintained, so that the helicoid ring 18 and the third outer cylinder 15 are in contact with the fixed ring 22. Movement in the optical axis direction is restricted and only rotation is performed.

  When the helicoid ring 18 rotates at a fixed position, the cam ring roller 32 is positioned in the circumferential groove 14e-1 of the roller guide through groove 14e, so that the cam ring 11 is also in the optical axis direction with respect to the rectilinear guide ring 14. Rotate in place without moving. That is, the first lens group LG1 and the second lens group LG2 are relatively moved in the optical axis direction along a predetermined locus according to the zoom areas of the second group guide cam groove 11a and the first group guide cam groove 11b, and zooming is performed.

  When the third outer cylinder 15 and the helicoid ring 18 are further rotated in the feeding direction from the telephoto end, and the rotational sliding protrusion 18b reaches the terminal end of the rotational sliding groove 22d as shown in FIGS. The lens barrel is disassembled so that the outer cylinder 15, the second outer cylinder 13, the first outer cylinder 12, and the like can be extracted forward. However, when the lens barrel stopper 26 is attached to the stopper insertion / removal hole 22e, the stopper abutting surface 18b-E of one rotational sliding protrusion 18b abuts on the lens barrel stopper 26 and rotates to the disassembly position. Therefore, the lens barrel is not disassembled 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 storage direction (downward in FIG. 22), the rotational sliding projection 18b and the fitting projection 15b are inclined in the rotational sliding groove 22d. Move to 22c side. During this time, similarly to the movement from the wide end to the tele end, the fitting protrusion 15b and the rotation sliding protrusion 18b are pressed against the opposing rotation guide surfaces 22d-A and 22d-B by the separation biasing spring 25, respectively. The third outer cylinder 15 and the helicoid ring 18 rotate together without causing backlash 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 circumferential surface 18b-B of the rotational sliding projection 18b comes into contact with the opposing oblique surface 22c-B of the oblique groove 22c. As a result, a component force is generated that moves the helicoid ring 18 backward in the optical axis direction along the opposite oblique surface 22c-B, and the helicoid ring 18 moves backward in the optical axis direction while rotating, contrary to the time when the rotation is extended. 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 back into the female helicoid 22a, and thereafter the male helicoid 18a and the female helicoid 22a Due to the screwing relationship, the helicoid ring 18 is rotated and stored until the storage position shown in FIGS. 20 and 24 is reached.

  When the helicoid ring 18 and the third lens barrel 15 move rearward in the optical axis direction, the rectilinear guide ring 14 also moves rearward, and the cam ring 11 supported by the rectilinear guide ring 14 also moves rearward. Further, when the helicoid ring 18 is switched from the fixed position rotation to the rotation storing 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 changes to the straight guide ring 14. On the other hand, it relatively moves backward in the optical axis direction while rotating.

  As described above, the zoom lens barrel 71 of the present embodiment is composed of the helicoid ring 18 that is the first-stage rotating ring and the rotation accompanying the movement in the optical axis direction of the third outer cylinder 15 and the second-stage rotating ring. Due to the rotation of the cam ring 11 with movement in the optical axis direction, movement between the thinnest storage position (FIG. 7) and the thickest maximum feeding position (wide end, FIG. 6) is performed. That is, when the movement from the stored state to the maximum feeding position is seen, the helicoid ring 18 and the third outer cylinder 15 move forward with respect to the stationary ring 22, and the helicoid ring 18 and the third outer cylinder 15 move forward. The cam ring 11 advances while rotating, the second outer cylinder 13 advances together, and the rotation of the cam ring 11 further advances the first outer cylinder 12 positioned inside the second outer cylinder 13. It is a lens barrel. After the cam ring 11, the third outer cylinder 15, and the helicoid ring 18 reach the maximum extension position, only the fixed position rotation that does not change the position in the optical axis direction is performed, and zooming is performed in the fixed position rotation. .

  Thus, according to the zoom lens barrel that expands and contracts in three steps, the amount of feeding to the maximum feeding position can be increased while shortening the storage length, and a small (thin) zoom lens barrel is obtained. Can do.

  Further, according to the illustrated embodiment, the male helicoid 18a, the female helicoid 22a, the rotational sliding protrusion 18b, the skew groove 22c, and the rotational sliding groove 22d, which are formed of concave and convex portions provided on the opposing peripheral surfaces of the helicoid ring 18 and the stationary ring 22, are provided. Only by this, it is possible to give the helicoid ring 18 both the rotation feeding (and rotation storing) operation accompanied by the movement in the optical axis direction and the fixed position rotation not accompanied by the movement in the optical axis direction. The helicoid fitting has a simple structure and high driving accuracy. Further, the rotational sliding protrusion 18b and the rotational sliding groove 22d for giving a fixed position rotation which cannot be given by the helicoid fitting have a simple structure composed of uneven portions as in the helicoid fitting, and the formation of the helicoid Since it is formed on the same peripheral surface as the surface, no special arrangement space is required. Therefore, a rotation feeding (and storage) operation and a fixed position rotation operation at the feeding position can be provided by a simple, compact and inexpensive structure.

  Since the zoom gear 28 is formed to have a length in the optical axis direction that can always mesh with the spur gear portion 18c regardless of the movement position of the helicoid ring 18, either the rotation extension of the helicoid ring 18 or the fixed position rotation is performed. The rotation can be given by the single zoom gear 28 as well. That is, the rotation transmission mechanism for the helicoid ring 18 that performs complex movement is configured simply and compactly, and the helicoid ring 18 and its internal structure can be driven with high accuracy.

  In addition, the zoom lens barrel 71 of the present embodiment is also characterized by the positional relationship between the zoom gear 28 and the rotary sliding protrusion 18b. As shown in FIG. 28, the rotational sliding protrusion 18b has a larger protruding amount in the outer diameter direction than the male helicoid 18a, and accordingly, the oblique groove 22c and the rotational sliding groove 22d are formed deeper than the female helicoid 22a. Has been. On the other hand, as shown in FIG. 29, the zoom gear 28 engages with the spur gear portion 18c formed on the male helicoid 18a, so that the outer edge portion thereof is more than the inner peripheral surface of the stationary ring 22 (the bottom portion of the female helicoid 22a). Projects in the inner diameter direction. In other words, in the radial direction (radial direction) centering on the lens barrel central axis Z0, the zoom gear 28 and the rotational sliding projection 18b are in a partially overlapping position (the center of the lens barrel when the zoom lens barrel 71 is viewed from the front). It is within a range equidistant from the axis Z0). However, as shown in FIGS. 24 to 27, the zoom gear 28 according to the present embodiment is located at a position different from the rotational sliding groove 22d in the optical axis direction, and further between the plurality of skew grooves 22c in the circumferential direction. It is positioned and is pivotally supported so as not to overlap with the movement trajectory of the rotary sliding protrusion 18b. Therefore, regardless of whether the rotational sliding protrusion 18b is located in the skew groove 22c or the rotational sliding groove 22d, it does not interfere with the zoom gear 28.

  Unlike the present embodiment, it is possible to avoid interference between the rotary sliding projection 18b and the zoom gear 28 by making the projection amount of the rotary sliding projection 18b in the outer diameter direction relatively smaller than that of the male helicoid 18a. . However, for example, when the amount of protrusion of the rotational sliding protrusion 18b is reduced, the amount of engagement with the rotational sliding groove 22d is reduced, and there is a risk that the rotational stability during rotation of the helicoid ring 18 at a fixed position is impaired. . Further, if the protrusion amount on the male helicoid 18a side is increased without changing the protrusion amount of the rotary sliding protrusion 18b, the radial positions of the stationary ring 22 and the zoom gear 28 are shifted to the outer diameter side accordingly. The entire lens barrel is increased in diameter. That is, in the solution method in which the radial size of the rotary sliding protrusion 18b and the male helicoid 18a is changed, there is a risk that the driving stability of the helicoid ring 18 and the compactness of the lens barrel may be sacrificed. On the other hand, according to the arrangement relationship between the zoom gear 28 and the rotary sliding protrusion 18b of the present embodiment shown in FIGS. 24 to 27, mutual interference can be prevented without such problems.

  As mentioned above, although this invention was demonstrated based on illustration embodiment, this invention is not limited to this embodiment. For example, in the embodiment, the rotational sliding protrusion 18b is provided as a convex portion on the helicoid ring 18 side, and the rotational sliding groove 22d (and the oblique groove 22c) is formed as a concave portion on the fixed ring 22 side. Even if the relationship is reversed, the driving mechanism of the helicoid ring 18 is established.

  Further, in the embodiment, in the helicoid ring 18, the rotational sliding protrusion 18b is formed forward of the male helicoid 18a in the optical axis direction, and in the fixed ring 22, the rotational sliding groove 22d is formed forward of the female helicoid 22a in the optical axis direction. However, by reversing this positional relationship, the male helicoid and the female helicoid are positioned in front of the rotational sliding protrusion and the circumferential groove (rotating sliding groove) in the optical axis direction, respectively. Is also possible.

  In the embodiment, the third outer cylinder 15 and the helicoid ring 18 are coupled and rotated, but the present invention can also be applied as a support structure for a single rotating ring. Specifically, the third outer cylinder 15 and the helicoid ring 18 in the embodiment may be integrated.

  Further, as described above, the larger the protrusion amount of the rotary sliding protrusion 18b in the outer diameter direction, the easier it is to obtain the positional accuracy of the helicoid ring 18 during the fixed position rotation. It is larger than the protruding amount of the male helicoid 18a. However, it is also possible to make the amount of protrusion of the rotary sliding protrusion 18b smaller than that of the embodiment so as to be equal to or less than that of the male helicoid 18a as long as the required positional accuracy is not impaired. In this case, interference between the rotary sliding protrusion 18b and the fixed ring 22 can be avoided without forming a clearance groove such as the skew groove 22c. That is, when the protruding amount of the rotary sliding protrusion 18b does not exceed the protruding amount of the male helicoid 18a, a non-helicoid region having a width (and direction) corresponding to the skew groove 22c is formed on the forming region of the female helicoid 22a. Just do it. Specifically, if the interval between some of the helicoid peaks of the female helicoid 22a is increased, a non-helicoid region replacing the skew groove 22c can be obtained. In other words, it can be said that the oblique groove 22 c is also a kind of non-helicoid region on the stationary ring 22.

  On the contrary, the skew groove 22c can be positively used as a mechanism for assisting the helicoid rather than a simple escape groove. In other words, in the embodiment, the circumferential surfaces 18b-A and 18b-B of the rotational sliding projection 18b are arranged in the oblique groove 22c so as not to interfere with the guide function by the helicoids 18a and 22a when the helicoid ring 18 rotates and retreats. It is not engaged with the opposing oblique surfaces 22c-A and 22c-B. However, if sufficient molding accuracy that does not hinder the guide function by the helicoid is obtained, the circumferential direction surfaces 18b-A and 18b-B and the opposing oblique surfaces 22c-A and 22c-B are engaged to rotate. It may be used as a guide surface during advancement and retreat.

  Further, in the embodiment, the rotational sliding protrusion 18b, the oblique groove 22c, the rotational sliding groove 22d, etc. are provided at three positions with different positions in the circumferential direction, but the number is other than three. May be.

  Further, in the above embodiment, in addition to the relationship between the helicoid ring 18 and the fixed ring 22, a rotation feeding operation and a fixed position rotation operation are selected for the cam ring 11 between the linear guide ring 14 and the cam ring 11. Are provided (roller guide through groove 14e and cam ring roller 32). As a result, the cam ring 11 is also provided with the rotation extension amount of the cam ring 11 relative to the linear guide ring 14 in addition to the rotation extension amount by the helicoid ring 18, so that the cam ring 11 is extended from the storage position to the use state. The amount can be increased.

1 is an exploded perspective view of a zoom lens barrel according to an embodiment of the present invention. FIG. 2 is an exploded perspective view of elements relating to a support mechanism for a first lens group in the zoom lens barrel of FIG. 1. FIG. 3 is an exploded perspective view of elements relating to a support mechanism for a second lens group in the zoom lens barrel of FIG. 1. FIG. 5 is an exploded perspective view of elements relating to a feeding mechanism from a fixed ring to a third outer cylinder in the zoom lens barrel of 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. It is a longitudinal cross-sectional view which shows the use state of a wide end and a tele end of the camera carrying the zoom lens barrel to which this invention is applied. It is a longitudinal cross-sectional view of the camera barrel storage state of the camera. It is a development top view of a fixed ring. It is an expansion | deployment top view of a helicoid ring. It is an expanded top view which shows through the component by the side of the internal peripheral surface of a helicoid ring. It is an expansion | deployment top view of a 3rd outer cylinder. It is an expansion | deployment top view of a rectilinear guide ring. It is an expansion | deployment top view of a cam ring. It is a development top view seeing through and showing the 2nd group guide cam groove of the inner peripheral surface side of a cam ring. It is an expansion | deployment top view of a rectilinear guide ring. It is a development top view of the 2nd group lens movement frame. It is an expansion | deployment top view of a 2nd outer cylinder. It is an expansion | deployment top view of a 1st outer cylinder. It is a figure which shows notionally the operation | movement relationship of the main components of the zoom lens barrel of this embodiment. It is an expansion | deployment top view which shows the relationship between the helicoid ring in a lens-barrel accommodation state, a 3rd outer cylinder, and a fixed ring. It is an expansion | deployment top view which shows the relationship between the helicoid ring in a wide end, a 3rd outer cylinder, and a fixed ring. It is an expansion | deployment top view which shows the relationship between the helicoid ring in a tele end, a 3rd outer cylinder, and a fixed ring. It is an expansion | deployment top view which shows the relationship between the helicoid ring in a lens-barrel decomposition | disassembly state, a 3rd outer cylinder, and a fixed ring. It is an expansion | deployment top view of a stationary ring which shows the position of the rotation sliding protrusion of a helicoid ring in a lens-barrel accommodation state. It is an expansion | deployment top view of a stationary ring which shows the position of the rotation sliding protrusion of a helicoid ring in a wide end. It is an expansion | deployment top view of a stationary ring which shows the position of the rotation sliding protrusion of the helicoid ring in a tele end. It is an expansion | deployment top view of a stationary ring which shows the position of the rotation sliding protrusion of a helicoid ring in a lens-barrel decomposition | disassembly state. FIG. 25 is a cross-sectional view of a helicoid ring and a stationary ring along the line XXVIII-XXVIII in FIG. 24. It is sectional drawing of the helicoid ring vicinity which follows the XXIX-XXIX sectional line of FIG.

Explanation of symbols

LG1 first lens group (optical element, movable lens group)
LG2 Second lens group (optical element, movable lens group)
LG3 Third lens group LG4 Low pass filter S Shutter A Aperture Z0 Lens barrel central axis (rotation central axis)
Z1 Shooting optical axis Z2 Retraction optical axis Z3 Viewfinder objective optical axis 1 First lens group frame 1a Male adjusting screw 2 First group adjusting ring 2a Female adjusting screw 2b Guide protrusion 2c Engaging claw 3 First group retaining ring 3a Spring receiving part 6 Second group lens frame 8 Second group lens moving frame 8a Straight guide groove 8b Second group cam follower 8b-1 Front cam follower 8b-2 Rear cam follower 10 Second group straight guide ring 10a Crotch protrusion 10b Ring portion 10c Straight guide key 11 Cam ring ( Second rotating ring)
11a 2 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 engaging projection 12b first group adjusting ring guide Groove 13 Second outer cylinder 13a Linear guide protrusion 13b Linear guide groove 13c Inner diameter flange 14 Linear guide ring 14a Linear guide protrusion 14b 14c Relative rotation guide protrusion 14d Circumferential groove 14e Roller guide through groove 14e-1 14e-2 Circumferential groove 14e-3 lead groove portion 14f first rectilinear guide groove 14g second rectilinear guide groove 15 third outer cylinder (first rotating ring)
15a Rotation transmission protrusion 15b Fitting protrusion 15c Spring contact recess 15d Relative rotation guide protrusion 15e Circumferential groove 15f Roller engagement groove 17 Roller biasing spring 17a Roller pressing piece 18 Helicoid ring (first rotation ring)
18a Male helicoid (advance / retreat mechanism)
18b Rotating sliding protrusion (Rotating guide protrusion)
18b-A 18b-B Circumferential surface 18b-C Front sliding surface 18b-D Rear sliding surface 18b-E Stopper contact surface 18c Spur gear part (circumferential gear part)
18d Rotation transmission recess 18e Fitting recess 18f Spring insertion recess 18g Circumferential groove 21 CCD holder 21a Cam projection 22 Fixed ring (annular member)
22a Female helicoid (advance / retreat mechanism)
22b Straight guide groove 22c Skew groove (no helicoid area)
22c-A 22c-B Opposing skew surface 22d Rotating sliding groove (circumferential groove)
22d-A 22d-B Rotation guide surface 22e Stopper insertion / removal hole 22z Front annular region 24 Group 1 biasing spring 25 Separating direction biasing spring 26 Lens barrel stopper 28 Zoom gear (drive gear)
29 Zoom gear shaft 30 Finder gear 31 Group 1 roller (cam follower)
32 Cam ring roller (cam follower)
32a Roller fixing screw 33 2nd group rotation shaft 35 Rotation restriction pin 36 37 2nd group lens frame support plate 38 Axial pressure spring 39 2nd group lens frame return spring 51 AF lens frame (3rd group lens frame)
52 53 AF guide shaft 54 AF nut 55 AF frame biasing spring 60 CCD (solid-state imaging device)
61 packing 62 CCD base plate 64 retaining ring fixing screw 66 support plate fixing screw 70 digital camera 71 zoom lens barrel 72 camera body 73 filter holder 74 deceleration gear box 75 lens drive control FPC board 76 shutter unit 77 exposure control FPC board 80 viewfinder Unit 81a Objective window 81b 81c Movable zoom lens 81d Prism 81e Eyepiece lens 81f Eyepiece window 83 84 Holding frame 85 86 Guide shaft 90 Cam gear 101 Barrier cover 102 Barrier pressure plate 103 Barrier drive ring 104 105 Barrier blade 106 Barrier biasing spring 107 Barrier Driving ring biasing spring 140 Control circuit 150 Zoom motor 160 AF motor

Claims (4)

Fixed ring:
A first rotating ring that moves in the optical axis direction while rotating between moving ends that are respectively defined before and after the optical axis direction with respect to the fixed ring, and that rotates at a fixed position at the moving end in front of the optical axis direction;
A second rotating ring that moves in the optical axis direction while rotating between moving ends that are respectively defined before and after the optical axis direction with respect to the first rotating ring, and that rotates at a fixed position at the moving end in front of the optical axis direction. And a first outer cylinder that advances and retracts in the optical axis direction with respect to the second rotary ring by rotation accompanied by movement of the second rotary ring in the optical axis direction;
With
The rotation between the storage position and the maximum extension position of the zooming area is performed by rotation accompanied by movement in the optical axis direction between the moving ends of the first rotation ring and the second rotation ring before and after the optical axis direction, A zoom lens barrel characterized in that a zooming action is executed by the fixed position rotation at the forward moving end of each of the first rotating ring and the second rotating ring. The zoom lens barrel according to claim 1, wherein the maximum extension position of the zooming region is a wide end. 3. The zoom lens barrel according to claim 1, wherein the second rotating ring is rotated by the rotational force of the first rotating ring. 4. The zoom lens barrel according to claim 1, wherein the first rotating ring has a third outer cylinder that moves together in the optical axis direction, and the second rotating ring is in the optical axis direction. A zoom lens mirror having a second outer cylinder that moves together, wherein the first outer cylinder, the second outer cylinder, and the third outer cylinder are sequentially positioned from the inner diameter side to the outer diameter side in this order. Tube.

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