JP2017161814A - Lens barrel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lens barrel capable of not imparting a discomfort feeling to a user by enhancing the operation sound.SOLUTION: A boundary BD 1 between an imaging area and a transition area is shifted per each cum groove. Consequently, when three cum pins 23 b move from imaging areas 13 dAa, 13 dBa, and 13 dCa to transition areas 13 dAC, 13 dBc, and 13 dCc or move to the opposite direction by being rotated relative to the first cum cylinder 13 and a third mirror frame 23, the three cum pins 23 b pass through the boundary BD, while shifting timing. For this reason, even if a frictional force received by the cum pin 23 b from each cum groove is different at the imaging area and the transition area during relative sliding, the timing of passing through the boundary BD 1 by the cum pin 23 b is shifted so as to gradually change a load, and the operation sound of the actuator can be gradually changed, and little fear is generated to impart a discomfort feeling to a user.SELECTED DRAWING: Figure 7

Description

  The present invention relates to a lens barrel that enables displacement of a lens in the optical axis direction.

  In a lens barrel mounted on a camera capable of zoom photography, etc., a cam follower provided on a moving frame holding a zoom lens is engaged with a cam groove formed in the cam ring, and the moving frame and the cam ring are rotated relative to each other. By moving the zoom lens, the displacement of the zoom lens in the optical axis direction is accurately performed.

  By the way, the cam ring used for the lens barrel can be formed of resin including the cam groove by using injection molding using a mold or the like. However, in the machining of such a mold, if the entire cam groove is accurately formed, there is a problem that the machining cost increases. On the other hand, since the cam groove requires accuracy only in a range used for zoom photography or the like (referred to as a high accuracy range), there is a situation that it is not necessary to form the entire cam groove with high accuracy. Therefore, in the metal mold used for molding, the cost is reduced by accurately processing only the portion corresponding to the required high accuracy range of the cam groove transfer portion. On the other hand, parts corresponding to a range other than the required high accuracy range in the cam groove transfer portion do not require high-precision processing. However, even if manufacturing errors are taken into consideration, cam grooves outside the required high accuracy range are required. It is desirable to process the mold so that a certain amount of backlash or clearance is provided so that there is no interference between the cam follower and the cam follower.

  For example, in Patent Document 1, in a lens barrel that drives a zoom lens using a cam groove and a cam follower, a cam slope is divided into a shooting area for guiding the zoom lens with high accuracy and a non-shooting area other than that. Proposed lens barrels with different tilt and groove width, that is, the backlash between the cam groove and cam follower is minimized in the shooting area and the backlash between the cam groove and cam follower is increased in the non-shooting area. Has been.

JP 2000-275498 A

  However, if the cam groove has both a shooting area with a small play between the cam follower and a non-shooting area with a large play between the cam follower, the moving frame and the cam ring are rotated relative to each other using an actuator. At this time, when the cam follower slides and moves from the imaging region to the non-imaging region, the load suddenly decreases, while when the cam follower slides and moves from the non-imaging region to the imaging region, the load suddenly increases. If the load suddenly changes in this way, the driving sound of the actuator may change and the user may feel uncomfortable. Even in the non-photographing area, it is necessary to further reduce the backlash between the cam groove and the cam follower in the range in which the initial position of the zoom lens is detected, and the same problem may occur.

  An object of the present invention is to provide a lens barrel that can prevent the user from feeling uncomfortable by improving the operation sound.

The lens barrel of the present invention is a lens barrel that holds a lens movably in the optical axis direction.
A cylindrical member having a first engagement groove and a second engagement groove on the peripheral surface;
A moving frame that includes a first engagement piece that engages with the first engagement groove and a second engagement piece that engages with the second engagement groove, and holds the lens. Have
When the cylindrical member and the moving frame are relatively rotated, the first engaging piece moves along the first engaging groove, and the second engaging groove moves along the second engaging groove. When the second engagement piece moves, the lens is positioned in the optical axis direction,
The first engagement groove includes an eleventh groove portion that slides with a first frictional force with respect to the first engagement piece, and a first frictional force with respect to the first engagement piece. A twelfth groove that slides with a small second frictional force,
The second engagement groove includes a twenty-first groove portion that slides with a third frictional force with respect to the second engagement piece, and a third frictional force with respect to the second engagement piece. A 22nd groove that slides with a small fourth frictional force,
The timing at which the first engagement piece passes between the eleventh groove portion and the twelfth groove portion when the cylindrical member and the moving frame are relatively rotated is the second engagement piece. Is different from the timing of passing between the 21st groove portion and the 22nd groove portion.

  ADVANTAGE OF THE INVENTION According to this invention, the lens barrel which can make a user feel uncomfortable by improving an operating sound can be provided.

It is sectional drawing of the lens barrel of a retracted state. It is sectional drawing of the lens barrel extended | drawn out to the wide angle end. It is sectional drawing of the lens barrel extended to the telephoto end. It is a disassembled perspective view of the lens barrel rear part. It is a disassembled perspective view of a lens barrel front part. FIG. 3 is a development view of the inner peripheral surface of the first cam cylinder 13. FIG. 6A shows an enlarged view of the part indicated by arrow VIIA in FIG. 6, FIG. 6B shows an enlarged view of the part indicated by arrow VIIB in FIG. 6, and shows an enlarged view of the part indicated by arrow VIIC in FIG. (C). FIG. 6A shows an enlarged view of the part indicated by arrow VIIIA in FIG. 6, FIG. 6B shows an enlarged view of the part indicated by arrow VIIIB in FIG. 6, and shows an enlarged view of the part indicated by arrow VIIIC in FIG. (C). It is the figure which cut | disconnected the structure of Fig.7 (a) by the VIII-VIII line and looked at the arrow direction. It is an expanded view of the internal peripheral surface of 1st cam cylinder 13 'concerning a comparative example. FIG. 10A shows an enlarged view of the part indicated by arrow XIA in FIG. 10, FIG. 10B shows an enlarged view of the part indicated by arrow XIB in FIG. 10, and shows an enlarged view of the part indicated by arrow XIC in FIG. (C). FIG. 10A shows an enlarged view of the part indicated by arrow XIIA in FIG. 10, FIG. 10B shows an enlarged view of the part indicated by arrow XIIB in FIG. 10, and shows an enlarged view of the part indicated by arrow XIIC in FIG. (C). FIG. 7 is a developed view similar to FIG. 6 of a first cam cylinder 113 according to a modification according to the present embodiment. FIG. 9 is an enlarged view similar to FIG. 7A showing one cam groove 213dA according to a modification. It is the figure which cut | disconnected the structure of FIG. 14 by the XV-XV line | wire and looked at the arrow direction. FIG. 7 is a development view similar to FIG. 6 of a helicoid cylinder 313 according to another embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The actual lens barrel is mounted on a camera or the like. 1 is a cross-sectional view of a retracted lens barrel, FIG. 2 is a cross-sectional view of a lens barrel extended to the wide-angle end, FIG. 3 is a cross-sectional view of the lens barrel extended to the telephoto end, and FIG. FIG. 5 is an exploded perspective view of the front part of the lens barrel.

  The imaging lens mounted on the lens barrel is a zoom lens, and includes a first lens group L1, a second lens group L2, a third lens group L3, and a fourth lens group L4. In zooming, each lens group moves in the optical axis direction while changing the inter-group distance, and in focusing, the fourth lens group L4 moves in the optical axis direction.

  Next, a configuration for moving the first lens unit L1, the second lens unit L2, and the third lens unit L3 according to the present invention will be described. In the following description, the front or front means the subject side, and the rear or rear means the imaging surface side.

  A holding plate 11 and a fixed cylinder 12 that are not moved at the time of zooming or focusing are integrally coupled to the rear part of the lens barrel. The holding plate 11 holds an image sensor (not shown), and the fixed cylinder 12 holds various lens barrels, lens frames, and the like described later. When the lens barrel is attached to the camera body, the holding plate 11 is fixed to the camera body.

  A first cam cylinder 13 (cylinder member) that moves in the optical axis direction while rotating with respect to the fixed cylinder 12 is provided inside the fixed cylinder 12. A gear 13 a is formed at the rear of the outer peripheral surface of the first cam cylinder 13 as shown in FIGS. 3 and 4, and the gear 13 a meshes with a long gear 14 arranged in the fixed cylinder 12 in the axial direction. In addition, although only one is shown in FIG. 4 on the outer peripheral surface of the first cam cylinder 13, three are equally arranged at intervals of 120 degrees in the circumferential direction (hereinafter referred to as “three equal distribution”). A cam pin 13b protrudes, and the cam pin 13b engages with a cam groove 12a provided on the inner peripheral surface of the fixed cylinder 12 in three equal portions. Accordingly, when the long gear 14 is rotated by being driven by a zoom motor (not shown), the first cam cylinder 13 is rotated via the gear 13a and moved in the optical axis direction based on the cam groove 12a via the cam pin 13b.

  A first rectilinear cylinder 15 that moves with the first cam cylinder 13 while being prevented from rotating by the fixed cylinder 12 is provided inside the first cam cylinder 13. The first rectilinear cylinder 15 is assembled integrally with the first cam cylinder 13, and both are rotatable with respect to each other, but are not separated in the optical axis direction. At the rear of the outer peripheral surface of the first rectilinear cylinder 15, the rotation preventing portion 15 a protrudes in three equal parts, and the rotation preventing part 15 a is a rectilinear groove 12 b provided in parallel with the optical axis O on the inner peripheral surface of the fixed cylinder 12. Is engaged. Therefore, when the first cam cylinder 13 rotates and moves in the optical axis direction, the first rectilinear cylinder 15 is prevented from rotating by the rectilinear groove 12b via the rotation preventing portion 15a, and the first cam cylinder 13 is moved accordingly. And only go straight ahead.

  As shown in FIG. 3, an L-shaped blade member 15e is attached so as to protrude from the rear end of the first rectilinear cylinder 15, and the holding plate 11 faces the blade member 15e. An optical sensor PI is arranged. Although details will be described later, when the blade member 15e is displaced in the optical axis direction together with the first rectilinear cylinder 15, the optical sensor PI is blocked as indicated by a dotted line. An initial position can be detected. The blade member 15e and the optical sensor PI are not shown except for FIG.

  A second cam cylinder 16 that moves in the optical axis direction while rotating is provided inside the first rectilinear cylinder 15. Further, a third cam cylinder 17 assembled integrally with the second cam cylinder 16 is provided inside the second cam cylinder 16. Cam pins 18 planted in the third cam cylinder 17 are erected at the rear part of the outer peripheral surface of the second cam cylinder 16 so that the cam pins 18 pass through the through holes 16 a provided in the second cam cylinder 16. In addition, the cam groove 15 b provided in the first rectilinear cylinder 15 is passed through and engaged with the drive groove 13 c provided in the first cam cylinder 13. Therefore, when the first cam cylinder 13 rotates, the drive groove 13c rotates the cam pin 18, and the cam pin 18 moves in the optical axis direction based on the cam groove 15b. Therefore, the second cam cylinder 16 and the third cam cylinder 17 are rotationally moved in the optical axis direction by the rotational movement of the cam pin 18.

  A second rectilinear cylinder 19 is provided inside the third cam cylinder 17 so as to move together with the second cam cylinder 16 and the third cam cylinder 17 while being prevented from rotating by the first rectilinear cylinder 15. The second rectilinear cylinder 19 is assembled integrally with the third cam cylinder 17 and is rotatable with respect to each other, but is not separated in the optical axis direction. At the rear of the outer peripheral surface of the second rectilinear cylinder 19, the rotation preventing portion 19 a protrudes in a three-way manner, and the rotation preventing portion 19 a is arranged in a three-way manner in parallel with the optical axis O on the inner peripheral surface of the first rectilinear tube 15. It is engaged with the provided rectilinear groove 15c. Accordingly, when the second rectilinear cylinder 19 moves in the optical axis direction while the second cam cylinder 16 and the third cam cylinder 17 rotate, the second rectilinear cylinder 19 is rotated by the rectilinear groove 15c via the rotation blocking portion 19a. Thus, only the straight movement is performed as the second cam cylinder 16 and the third cam cylinder 17 move.

  A first lens frame 21 that holds the first lens unit L1 is provided inside the second rectilinear barrel 19. The first lens frame 21 has arm portions 21a arranged in a three-way manner so as to extend rearward, and a cam pin 21c is erected on a rear portion 21b of the arm portion 21a. The rear portion 21 b is engaged with the long groove 19 b provided in the second rectilinear cylinder 19, and the cam pin 21 c is engaged with the cam groove 17 a provided in the third cam cylinder 17. Accordingly, the first lens frame 21 is prevented from rotating by the long groove 19b via the rear portion 21b, and moves linearly based on the cam groove 17a via the cam pin 21c due to the rotation of the third cam cylinder 17. ing.

  A second lens frame 22 that holds the second lens unit L2 is provided inside the second rectilinear barrel 19. In the second lens frame 22, square protrusions 22a stand upright on the outer peripheral surface, and cam pins 22b stand upright on the protrusions 22a. The protrusion 22 a is engaged with the long groove 19 c provided in the second rectilinear cylinder 19, and the cam pin 22 b is engaged with the cam groove 17 b provided in the third cam cylinder 17. Accordingly, the second lens frame 22 is prevented from rotating by the long groove 19c through the protrusion 22a, and moves linearly based on the cam groove 17b through the cam pin 22b by the rotation of the third cam cylinder 17. ing.

  A decorative frame 31 that covers the inside of the lens barrel from the front is provided between the second cam cylinder 16 and the third cam cylinder 17. The decorative frame 31 has an opening 31a that allows subject light to pass through the first lens unit L1. In addition, a rectilinear plate 32 is integrally assembled with the second rectilinear cylinder 19 and disposed in front of the third cam cylinder 17. Cam pins 31 a are erected on the rear part of the decorative frame 31 in a six-way arrangement, and the cam pins 31 a are engaged with cam grooves 16 b that are six-way on the inner peripheral surface of the second cam cylinder 16. Therefore, the decorative frame 31 moves based on the cam groove 16b via the cam pin 31a as the second cam cylinder 16 rotates. On the other hand, a protrusion 32 a protruding from the outer periphery of the rectilinear plate 32 is engaged with a long groove (not shown) provided in parallel with the optical axis O on the inner peripheral surface of the decorative frame 31. Therefore, the decorative frame 31 only moves straight without rotating. The cam groove 16b of the second cam cylinder 16 has the same cam curve as the cam groove 17a of the third cam cylinder 17, so that the decorative frame 31 is the first lens frame 21, that is, the first lens group. It moves so that the distance from L1 is always kept constant.

  On the other hand, the third lens unit L3 is held by a third lens frame (moving frame) 23. The third lens frame 23 has three arm portions 23a, and cam pins 23b are erected on the arm portions 23a. The arm portion 23a engages with a long groove 15d parallel to the optical axis O, which is arranged three-fold on the first rectilinear cylinder 15, and the cam pins 23b are formed on the inner peripheral surface of the first cam cylinder 13 in three-dimension. The cam groove 13d is engaged. Accordingly, the third lens frame 23 is moved based on the cam groove 13d via the cam pin 23b due to the rotation of the first cam barrel 13, and is prevented from rotating by the long groove 15d via the arm portion 23a. It is designed to move straight in the direction. Here, the three cam pins 23b form a first engagement piece, a second engagement piece, and a third engagement piece, respectively, and the three cam grooves 13d corresponding to the first engagement piece, the second engagement piece, and the third engagement piece respectively. The engaging groove, the second engaging groove, and the third engaging groove are formed. These details will be described later. The three cam pins 23b are disposed at the same position in the optical axis direction so as to protrude at substantially equal intervals in the circumferential direction. “Substantially equidistant” means that the axes of the cam pins 23b are arranged within a range of, for example, 120 ° ± 10 °, but are preferably arranged at equal intervals.

  A shutter unit 25 having a diaphragm and a sector is integrally fixed to the third lens frame 23.

  Although the fourth lens group L4 is held by the fourth lens frame 24, a drive mechanism for moving the fourth lens frame 24 in the optical axis direction is not shown, and any known mechanism may be used. Good. For example, a screw is provided in parallel with the optical axis O, a nut that is screwed into the screw and the fourth lens frame 24 are assembled integrally, and the nut is moved along the screw by rotating the nut with a dedicated focus motor. The fourth lens frame 24 may be moved in the direction of the optical axis by moving.

  The operation at the time of zooming in the above lens barrel will be described together. When the long gear 14 is rotated by a zoom motor (not shown), the first cam cylinder 13 moves in the optical axis direction based on the cam groove 12a while rotating. At this time, the first rectilinear cylinder 15 assembled integrally with the first cam cylinder 13 does not rotate, and only moves linearly as the first cam cylinder 13 moves. When the first cam cylinder 13 rotates, the cam pin 18 of the third cam cylinder 17 engaged with the drive groove 13c rotates, so that the integrally assembled second cam cylinder 16 and third cam cylinder 17 It moves based on the cam groove 15b while rotating. When the third cam cylinder 17 rotates, the first lens frame 21 holding the first lens group L1 and the second lens frame 22 holding the second lens group L2 are prevented from rotating by the second rectilinear cylinder 19, respectively. Based on the cam grooves 17a and 17b, it moves straight. At this time, the decorative frame 31 moves based on the cam groove 16b due to the rotation of the second cam cylinder 16, but the decorative frame 31 also moves straight because the rotation is blocked by the rectilinear plate 32.

  On the other hand, the third lens frame 23 that holds the third lens unit L3 by the rotation of the first cam barrel 13 moves linearly based on the cam groove 13d while being prevented from rotating by the first rectilinear barrel 15.

  In this way, the lens barrel is extended from the retracted state shown in FIG. 1 to the wide-angle end shown in FIG. 2, and finally extended to the telephoto state shown in FIG. Further, when the lens barrel is retracted to the wide-angle end or the retracted state, the zoom motor described above may be rotated in the reverse direction.

  FIG. 6 is a developed view of the inner peripheral surface of the first cam cylinder 13, but the drive groove 13c is omitted. 7 is an enlarged view of the portion indicated by arrow VIIA in FIG. 6A, FIG. 7B is an enlarged view of the portion indicated by arrow VIIB in FIG. 6, and the enlarged portion indicated by arrow VIIC in FIG. It is a figure (c) shown. 8 is an enlarged view of the portion indicated by arrow VIIIA in FIG. 6 (a), an enlarged view of the portion indicated by arrow VIIIB in FIG. 6 and an enlarged portion indicated by arrow VIIIC in FIG. It is a figure (c) shown. FIG. 9 is a view of the configuration of FIG. 7A cut along the line VIII-VIII and viewed in the direction of the arrow, but the same is true even if a cross-section is taken at the corresponding position in FIGS. 7B and 7C. . The enlarged view is drawn differently from the actual one for easy understanding.

  As shown in FIG. 9, both side surfaces of the cam groove 13d are inclined surfaces 13p that are separated from each other as the distance from the groove bottom 13t increases. The tapered surface 23c of the cam pin 23b having a taper angle substantially equal to the opening angle of the inclined surface 13p is slidable in contact with the inclined surface 13p.

  Hereinafter, when distinguishing the three cam grooves 13d, they are referred to as "cam groove 13dA", "cam groove 13dB", and "cam groove 13dC". The cam pins that engage and slide in the respective cam grooves 13d have the same shape and are therefore collectively referred to as “cam pins 23b”. In FIG. 6, the cam groove 13dA has a photographing region (11th groove) 13dAa in which the cam pin 23b slides during photographing, and a non-photographing region (12th groove) 13dAb in which the cam pin 23b slides during times other than photographing. . The non-imaging area 13dAb has a transition area (13th groove) 13dAc connected to the imaging area 13dAa.

  Here, as shown in FIG. 7, the groove width W1 of the imaging region 13dAa is, for example, about 0.1 mm smaller than the groove width W2 of the non-imaging region 13dAb in contact with the transition region 13dAc. The groove widths W1 and W2 here are measured at positions where the cam pins 23b come into contact. The groove width of the transition area 13dAc is gradually increased from the imaging area 13dAa toward the non-imaging area 13dAb.

  In FIG. 6, in the non-photographing area 13dAb, an initial position detection area 13dAd where the cam pin 23b is located when detecting the initial position using the blade member 15e is provided, and is connected to both ends of the initial position detection area 13dAd. In this manner, transition areas 13dAe and 13dAf that constitute a part of the non-imaging area 13dAb are provided. Here, the “non-imaging region 13dAb” does not include the initial position detection region 13dAd. The groove width of the initial position detection area 13dAd is smaller than the groove width of the non-photographing area 13dAb in contact with the transition areas 13dAe and 13dAf. Further, in order to set the initial position strictly, the groove width of the initial position detection area 13dAd is smaller than the groove width of the imaging area 13dAa, and the play with the cam pin 23b is further suppressed. In addition, the groove widths of the transition areas 13dAe and 13dAf are gradually increased from the initial position detection area 13dAd toward the non-imaging area 13dAb. The non-imaging area 13dAb closer to the image sensor than the transition area 13dAf is a retracted area used when the lens barrel is retracted (the same applies hereinafter).

  As is clear from the above, the imaging region 13dAa slides relative to the cam pin 23b with the first friction force F1, and the non-imaging region 13dAb relative to the cam pin 23b with the second friction force F2. The transition region 13dAc slides relative to the cam pin 23b with a fifth frictional force F5 (which varies depending on the position), and here, F1> F5> The relationship of F2 is established. In addition, when using a friction force in this specification, it shall include zero.

  In addition, the initial position detection region 13dAd slides relative to the cam pin 23b with the first friction force F1 ′, and the transition regions 13dAe and 13dAf include the fifth friction force F5 ′ ( However, in this case, the relationship of F1 ′> F5 ′> F2 is established.

  Further, in FIG. 6, the cam groove 13 dB has a photographing region (21st groove portion) 13 dBa where the cam pin 23 b slides during photographing and a non-photographing region (22nd groove portion) 13 dBb where the cam pin 23 b slides when not photographing. Have. The non-imaging area 13 dBb has a transition area (23rd groove) 13 dBc connected to the imaging area 13 dBa.

  Further, in the non-photographing area 13 dBb, an initial position detection area 13 dBd in which the cam pin 23 b slides when the initial position is detected using the blade member 15 e is provided, and is connected to both ends of the initial position detection area 13 dBd. Thus, transition regions 13 dBe and 13 dBf constituting a part of the non-photographing region 13 dBb are provided. Here, the “non-photographing region 13 dBb” does not include the initial position detection region 13 dBd. The groove width of the initial position detection area 13 dBd is smaller than the groove width of the non-imaging area 13 dBb in contact with the transition areas 13 dBe and 13 dBf. Further, in order to set the initial position strictly, the groove width of the initial position detection area 13 dBd is smaller than the groove width of the imaging area 13 dBa, and the play with the cam pin 23 b is further suppressed. The groove widths of the transition areas 13 dBe and 13 dBf gradually increase from the initial position detection area 13 dBd toward the non-imaging area 13 dBb.

  Similarly, the imaging region 13 dBa slides with the third frictional force F3 with respect to the cam pin 23b, the non-imaging region 13dBb slides with the fourth frictional force F4 with respect to the cam pin 23b, and the transition region 13dBc is The cam pin 23b slides with a sixth frictional force F6 (which varies depending on the position), and here, the relationship of F3> F6> F4 is established.

  In addition, the initial position detection region 13 dBd slides relative to the cam pin 23 b with the third friction force F 3 ′, and the transition regions 13 dBe and 13 dBf correspond to the sixth friction force F 6 ′ ( However, in this case, the relationship of F3 ′> F6 ′> F4 is established.

  Further, in FIG. 6, the cam groove 13dC has a photographing region (31st groove portion) 13dCa in which the cam pin 23b slides during photographing and a non-photographing region (32nd groove portion) 13dCb in which the cam pin 23b slides during times other than photographing. Have. The non-imaging area 13dCb has a transition area (33rd groove) 13dCc connected to the imaging area 13dCa.

  The non-photographing area 13dCb is provided with an initial position detection area 13dCd in which the cam pin 23b slides when detecting the initial position using the blade member 15e, and is connected to both ends of the initial position detection area 13dCd. Thus, transition regions 13dCe and 13dCf constituting a part of the non-photographing region 13dCb are provided. Here, the “non-imaging area 13dCb” does not include the initial position detection area 13dCd. The groove width of the initial position detection area 13dCd is smaller than the groove width of the non-photographing area 13dCb in contact with the transition areas 13dCe and 13dCf. In order to set the initial position strictly, the groove width of the initial position detection area 13dCd is smaller than the groove width of the imaging area 13dCa, and the play with the cam pin 23b is further suppressed. Further, the groove widths of the transition areas 13dCe and 13dCf are gradually increased from the initial position detection area 13dCd toward the non-imaging area 13dCb.

  Similarly, the imaging region 13dCa slides with respect to the cam pin 23b with the seventh friction force F7, the non-imaging region 13dCb slides with respect to the cam pin 23b with the eighth friction force F8, and the transition region 13dCc The cam pin 23b slides with a ninth frictional force F9 (which changes depending on the position), and here, the relationship of F7> F9> F8 is established.

  In addition, the initial position detection region 13dCd slides relative to the cam pin 23b with a seventh friction force F7 ′, and the transition regions 13dCe and 13dCf include a ninth friction force F9 ′ ( However, in this case, the relationship of F7 ′> F9 ′> F8 is established.

  FIG. 10 is a developed view of the inner peripheral surface of the first cam cylinder 13 ′ according to the comparative example, but the drive groove 13 c is omitted as in FIG. 6. 11 is an enlarged view of the portion indicated by arrow XIA in FIG. 10 (a), an enlarged view of the portion indicated by arrow XIB in FIG. 10 (b), and an enlarged portion indicated by arrow XIC in FIG. It is a figure (c) shown. FIG. 12 is an enlarged view of the part indicated by the arrow XIIA in FIG. 10 (a), an enlarged view of the part indicated by the arrow XIIB in FIG. 10 (b), and an enlarged part indicated by the arrow XIIC in FIG. It is a figure (c) shown.

  The first cam cylinder 13 'according to the comparative example has a cam groove 13d' extending along the same cam curve as that of the first cam cylinder 13 according to the present embodiment, but differs in detail. More specifically, referring to FIG. 11, in the case of the first cam cylinder 13 ′ according to the comparative example, the imaging regions 13dAa, 13dBa, 13dCa and the transition regions 13dAc, 13dBc, 13dCc (that is, non-imaging regions 13dAb, 13dBb). , 13dCb) is coincident with the optical axis direction (vertical direction in the figure). In addition, since the shape and width of the cam groove of the comparative example are the same as in this embodiment, the same frictional force relationship as that in this embodiment occurs.

  On the other hand, referring to FIG. 7, in the case of the first cam cylinder 13 according to the present embodiment, the imaging regions 13dAa, 13dBa, 13dCa and the transition regions 13dAc, 13dBc, 13dCc (that is, the non-imaging regions 13dAb, 13dBb, 13dCb) is deviated by a distance Δ in the optical axis direction (vertical direction in the figure). The boundaries between the transition areas 13dAc, 13dBc, 13dCc and the non-photographing areas 13dAb, 13dBb, 13dCb adjacent to the transition areas 13dAc, 13dBc, 13dCb are also shifted by the same distance Δ for each cam groove.

  The following effects arise from the difference in the above configuration. Since the cam pin 23b is provided at the same position in the optical axis direction, when the first cam cylinder 13 ′ of the comparative example is used, the first cam cylinder 13 ′ and the third lens frame 23 are rotated relative to each other by 3 When the cam pins 23b move from the imaging regions 13dAa, 13dBa, and 13dCa to the transition regions 13dAc, 13dBc, and 13dCc, respectively, or in the opposite direction, all the cam pins 23b pass through the boundary BD1 at the same time. become. As described above, the frictional force that the cam pin 23b receives from each cam groove at the time of relative sliding by the drive of the actuator differs between the imaging region and the transition region. Therefore, when the cam pin 23b passes the boundary BD1 simultaneously, the load changes simultaneously. As a result, the operating sound of the actuator changes greatly, and the user may feel uncomfortable.

  On the other hand, according to the first cam cylinder 13 according to the present embodiment, the boundary BD1 between the imaging region and the transition region is shifted for each cam groove. Therefore, when the three cam pins 23b move from the imaging regions 13dAa, 13dBa, and 13dCa to the transition regions 13dAc, 13dBc, and 13dCc, respectively, by the relative rotation of the first cam barrel 13 and the third lens frame 23, Alternatively, when moving in the opposite direction, the three cam pins 23b pass through the boundary BD1 while shifting the timing. Similarly, since the boundary between the transition region and the non-photographing region adjacent thereto is also shifted for each cam groove, the cam pin 23b passes through this boundary at different timings. For this reason, as in the comparative example, even if the frictional force received by the cam pin 23b from each cam groove during relative sliding by driving the actuator is different between the imaging region and the transition region, or between the transition region and the non-imaging region, the cam pin 23b Since the load changes stepwise by passing the boundary BD1, the operating sound of the actuator can be gradually changed, so that the user is less likely to feel uncomfortable.

  Similarly, referring to FIG. 12, in the case of the first cam cylinder 13 ′ according to the comparative example, the boundary BD2 between the initial position detection areas 13dAd, 13dBd, and 13dCd and one of the transition areas 13dAe, 13dBe, and 13dCe is the optical axis. The boundary BD3 between the initial position detection areas 13dAd, 13dBd, and 13dCd and the other transition areas 13dAf, 13dBf, and 13dCf coincides with the optical axis direction.

  On the other hand, referring to FIG. 8, in the case of the first cam cylinder 13 according to the present embodiment, the boundary BD2 between the initial position detection areas 13dAd, 13dBd, and 13dCd and one of the transition areas 13dAe, 13dBe, and 13dCe The optical axis direction (vertical direction in the figure) is shifted by a distance Δ, and the boundary BD3 between the initial position detection areas 13dAd, 13dBd, 13dCd and the other transition areas 13dAf, 13dBf, 13dCf is a distance in the optical axis direction. It is shifted by Δ. The boundaries between the transition areas 13dAe, 13dBe, 13dCe, 13dAf, 13dBf, and 13dCf and the non-photographing areas 13dAb, 13dBb, and 13dCb adjacent to the transition areas are also shifted by the same distance Δ for each cam groove.

  As is clear from the above, when the first cam cylinder 13 ′ of the comparative example is used, the three cam pins 23b are moved to the initial positions by the relative rotation of the first cam cylinder 13 ′ and the third lens frame 23, respectively. When the detection region 13dAd, 13dBd, 13dCd moves to one transition region 13dAe, 13dBe, 13dCe or the other transition region 13dAf, 13dBf, 13dCf, or when moving in the opposite direction, all the cam pins 23b are boundary BD2 Or it will pass BD3 simultaneously. Therefore, when the cam pin 23b passes through the boundary BD2 or BD3 at the same time, the load changes at the same time, the actuator operating sound changes greatly, and the user may feel uncomfortable.

  On the other hand, according to the first cam cylinder 13 according to the present embodiment, the boundaries BD2 and BD3 between the initial position detection region and the transition region are shifted for each cam groove. Therefore, the relative rotation between the first cam barrel 13 and the third lens frame 23 causes the three cam pins 23b to move from the initial position detection areas 13dAd, 13dBd, 13dCd to one transition area 13dAe, 13dBe, 13dCe, or the other. When moving to the transition regions 13dAf, 13dBf, and 13dCf (or moving in the opposite direction), the three cam pins 23b pass the boundaries BD2 and BD3 while shifting the timing. Similarly, since the boundary between the two transition areas and the non-photographing area adjacent thereto is also shifted for each cam groove, the cam pin 23b passes through the boundary at different timings. For this reason, as in the comparative example, even if the frictional force received by the cam pin 23b from each cam groove during relative sliding by driving the actuator is different between the initial position detection region and the transition region, or between the transition region and the non-photographing region, Since the timing at which the cam pin 23b passes the boundaries BD2 and BD3 is delayed, the load changes stepwise, and the operating sound of the actuator can be gradually changed, so that the user is less likely to feel discomfort.

  FIG. 13 is an unfolded view similar to FIG. 6 of the first cam cylinder 113 according to the modification according to the present embodiment. In this modification, three sub-grooves (impact mitigation engagement grooves) DM each having a similar cam curve are provided between the cam grooves 13dA, 13dB, and 13dC. Although not shown, the third lens frame 23 is provided with six equally spaced cam pins 23b, of which three cam pins (corresponding to impact reducing engagement pieces) 23b are located in the sub-groove DM. Is arranged. Since the secondary groove DM is intended to reduce the drop impact, the cam groove and the cam pin are designed not to be actively engaged, and the secondary groove DM has a uniform cross-sectional shape. Is larger than the width of the cam groove in the imaging region in the cam grooves 13dA, 13dB, and 13dC.

  In a normal operation, when the first cam barrel 113 and the third lens frame 23 are relatively rotated, the cam pin 23b is relatively slid along the cam grooves 13dA, 13dB, and 13dC as in the above-described embodiment. The lens is positioned. On the other hand, when the lens barrel is accidentally dropped, a large impact force may act between the first cam barrel 113 and the third lens frame 23. At this time, the cam grooves 13dA, 13dB, In addition to 13 dC, the cam pin 23b abuts on the three sub-grooves DM so as to disperse and support the impact force, thereby suppressing breakage of each part. Other configurations are the same as those of the above-described embodiment. Instead of providing the sub-grooves, six cam grooves having a deviated boundary may be provided as in the embodiment shown in FIGS.

  FIG. 14 is an enlarged view similar to FIG. 7A showing one cam groove 213dA according to a modification. FIG. 15 is a view of the configuration of FIG. 14 taken along line XV-XV and viewed in the direction of the arrow. In this modification, the cam pin 23b has a tapered surface 23c as in the above-described embodiment, but has a flat surface 23d at the tip thereof.

  On the other hand, the cam groove 213dA has an imaging region (11th groove portion) 213dAa and a non-imaging region (12th groove portion) 213dAb across the boundary BD1 as in the above-described embodiment. The non-imaging area 213dAb has a transition area (13th groove) 213dAc connected to the imaging area 213dAa.

  As shown in FIG. 14, the cam groove 213dA has the same groove width in the imaging region 213dAa and the non-imaging region 213dAb. However, as shown in FIG. 15, the depth D2 from the surface (inner circumferential surface) of the first cam cylinder 213 to the groove bottom 13tb of the non-photographing region 213dAb from the depth D1 from the groove bottom 13ta of the photographing region 213dAa. Is deeper. Further, the groove bottom 13tc of the transition region 13dAc is a slope connecting the groove bottom 13ta and the groove bottom 13tb.

  As is clear from the above, the imaging region 213dAa slides relative to the cam pin 23b with the first friction force F11, and the non-imaging region 213dAb relative to the cam pin 23b with the second friction force F12. The transition region 213dAc slides relative to the cam pin 23b with the fifth frictional force F15, and here, the relationship of F11> F15> F12 is established. Although not shown, this modification has two cam grooves, and has a common shape except that the position of the boundary BD1 is shifted.

  According to this modification, the boundary BD1 between the imaging region and the transition region (non-imaging region) is shifted for each cam groove. Therefore, when the three cam pins 23b move from the imaging area 213dAa to the transition area 213dAc, respectively, or in the opposite direction due to relative rotation between the first cam barrel 13 and the third lens frame 23. The three cam pins 23b pass through the boundary BD1 while shifting the timing. For this reason, even when the friction force received by the cam pin 23b from each cam groove at the time of relative sliding by driving of the actuator is different between the imaging region and the transition region, the timing at which the cam pin 23b passes the boundary BD1 is delayed. Since this changes in steps, the operating sound of the actuator can be gradually changed, so that the user is less likely to feel uncomfortable.

  Furthermore, also in this modification, an initial position detection area can be provided, and the user can be prevented from feeling uncomfortable by shifting the boundary as in the above-described embodiment.

  FIG. 16 is a developed view similar to FIG. 6 of a helicoid cylinder 313 according to another embodiment. The helicoid cylinder (engagement cylinder) 313 of this modification forms helicoid grooves (engagement grooves) HG1, HG2, HG3 instead of cam grooves. A helicoid (engagement piece) protruding from a lens frame (not shown) is slidably engaged with the helicoid grooves HG1, HG2, HG3. Although not shown, the helicoid that engages with the first helicoid groove HG1, the helicoid that engages with the second helicoid groove HG2, and the helicoid that engages with the third helicoid groove HG3 are substantially equal in the circumferential direction. It is provided at intervals.

  The first helicoid groove HG1 has a photographing region (11th groove) HG1a used at the time of photographing and a non-photographing region (twelfth groove) HG1b not used at the time of photographing with the boundary BD1 interposed therebetween. The non-photographing region HG1b has a transition region (a thirteenth groove) HG1c connected to the photographing region HG1a.

  In addition, an initial position detection region HG1d where a helicoid is located when detecting the initial position is provided in the non-photographing region HG1b, and both ends of the initial position detection region HG1d are connected to the non-photographing region HG1b. Transition regions HG1e and HG1f are provided. Here, the “non-photographing region HG1b” does not include the initial position detection region HG1d.

  Also in the present embodiment, since the shape of each region of the helicoid groove HG1 is different, the imaging region HG1a slides relative to the helicoid with the first frictional force F21, and the non-imaging region HG1b The transition region HG1c slides relative to the helicoid with the second frictional force F22, and slides relative to the helicoid with the fifth frictional force F25. Here, F21> The relationship F25> F22 is established.

  In addition, the initial position detection region HG1d slides relative to the helicoid with the first friction force F21 ′, and the transition regions HG1e and HG1f move relative to the helicoid with the fifth friction force F25 ′. Here, the relationship of F21 ′> F25 ′> F22 is established.

  Further, the second helicoid groove HG2 has a photographing region (21st groove portion) HG2a used at the time of photographing and a non-photographing region (22nd groove portion) HG2b not used at the time of photographing with the boundary BD1 interposed therebetween. The non-photographing area HG2b has a transition area (23rd groove) HG2c connected to the photographing area HG2a.

  Further, in the non-photographing area HG2b, an initial position detection area HG2d where a helicoid is located when detecting the initial position is provided, and both ends of the initial position detection area HG2d are connected to the non-photographing area HG2b. Transition regions HG2e and HG2f are provided. Here, the “non-imaging region HG2b” does not include the initial position detection region HG2d.

  Similarly, since the shape of each region of the helicoid groove HG2 is different, the imaging region HG2a slides relative to the helicoid with the third frictional force F23, and the non-imaging region HG2b corresponds to the helicoid. 4 and the transition region HG2c slides relative to the helicoid at a sixth friction force F26. Here, the relationship of F23> F26> F24 is established. Is established.

  In addition, the initial position detection region HG2d slides relative to the helicoid with the third friction force F23 ′, and the transition regions HG2e and HG2f relative to the helicoid with the sixth friction force F26 ′. Here, the relationship of F23 ′> F26 ′> F22 is established.

  Further, the third helicoid groove HG3 has a photographing area (31st groove) HG3a used at the time of photographing and a non-photographing area (32nd groove) HG3b not used at the time of photographing with the boundary BD1 interposed therebetween. The non-photographing area HG3b has a transition area (33rd groove) HG3c connected to the photographing area HG3a.

  Further, in the non-photographing area HG3b, an initial position detection area HG3d where a helicoid is located when detecting the initial position is provided, and both ends of the initial position detection area HG3d are connected to the non-photographing area HG3b. Transition regions HG3e and HG3f are provided. Here, the “non-photographing region HG3b” does not include the initial position detection region HG3d.

  Similarly, since the shape of each area of the helicoid groove HG3 is different, the imaging area HG3a slides relative to the helicoid with the seventh frictional force F37, and the non-imaging area HG3b corresponds to the helicoid. The transition region HG2c slides relative to the helicoid at a ninth friction force F39, and here, the relationship of F37> F39> F38 is established. Is established.

  In addition, the initial position detection region HG3d slides relative to the helicoid with the seventh friction force F33 ′, and the transition regions HG3e and HG3f move relative to the helicoid with the ninth friction force F39 ′. Here, the relationship of F37 ′> F39 ′> F38 is established.

  According to the helicoid cylinder 313 according to the present embodiment, the boundary BD1 between the imaging region and the transition region in the helicoid groove is shifted for each cam groove. Therefore, when the three helicoids move from the imaging regions HG1a, HG2a, and HG3a to the transition regions HG1c, HG2c, and HG3c by the relative rotation of the helicoid cylinder 313 and the lens frame (not shown), or When moving in the reverse direction, the three helicoids pass through the boundary BD1 while shifting the timing. For this reason, even if the frictional force that the helicoid receives from each helicoid groove during relative sliding by driving the actuator differs between the initial position detection region and the transition region, the timing at which the helicoid passes through the boundary BD1 is delayed, so that the load is reduced. Since it changes stepwise, the operating sound of the actuator can be gradually changed, so that the user is less likely to feel discomfort.

  Furthermore, according to the helicoid cylinder 313 according to the present embodiment, the boundaries BD2 and BD3 between the initial position detection region and the transition region are shifted for each cam groove. Therefore, by the relative rotation of the helicoid cylinder 313 and the lens frame (not shown), the three helicoids are respectively moved from the initial position detection areas HG1d, HG2d, HG3d to one transition area HG1e, HG2e, HG3e or the other transition. When moving to the regions HG1f, HG2f, and HG3f (or moving in the opposite direction), the three helicoids pass through the boundaries BD2 and BD3 while shifting the timing. For this reason, even if the friction force received by the helicoid from each helicoid groove during relative sliding by driving the actuator differs between the initial position detection region and the transition region, the timing at which the helicoid passes the boundaries BD2 and BD3 is Since the load changes stepwise, the operation sound of the actuator can be gradually changed, so that the user is less likely to feel uncomfortable.

  In the above embodiment, it is assumed that three cam pins or helicoids are arranged at the same position in the optical axis direction, and therefore the boundaries BD1, BD2, and BD3 are shifted in the optical axis direction. However, the present invention is not limited to this, and when the cam pins or helicoids are arranged shifted in the optical axis direction, the boundaries BD1, BD2, BD3 can be made to coincide with the optical axis direction. That is, it is sufficient that the cam pins or helicoids pass through the boundaries BD1, BD2, and BD3, respectively, at different timings. Any number of cam grooves or helicoid grooves may be provided as long as there are two or more. Further, the present invention may be applied not only to the first cam cylinder but also to other cam cylinders. In addition, in a lens barrel that does not detect the initial position in the optical axis direction, it is a matter of course that a portion in which the width of the cam groove is narrowed to detect the initial position is unnecessary.

L1 First lens group L2 Second lens group L3 Third lens group O Optical axis 12 Fixed cylinder 13 First cam cylinder 13c Driving grooves 13d, 13dA, 13dB, 13dC Cam grooves 13dAa, 13dBa, 13dCa Imaging regions 13dAb, 13dBb, 13dCb Non-imaging area 13dAc, 13dBc, 13dCc Transition area 13dAd, 13dBd, 13dCd Initial position detection area 13dAe, 13dBe, 13dCe Transition area 13dAf, 13dBf, 13dCf Transition area 13p Slope 13t, 13ta, 13tb, 13tc Cylinder bottom 15 first straight 15b Cam groove 16 Second cam cylinder 17 Third cam cylinders 18 and 23b Cam pin 19 Second rectilinear cylinder 21 First lens frame 22 Second lens frame 23 Third lens frame 31 Cosmetic frame 113 Cam cylinder 213dA Cam groove 213dAa Imaging region 213dAb Non Shooting area 213dAc Transition region 313 Helicoid cylinder BD1, BD2, BD3 Boundary DM Secondary groove HG1 Helicoid groove HG1, HG2, HG3 Helicoid groove HG1a, HG2a, HG3a Imaging region HG1b, HG2b, HG3b Non-imaging region HG1c, HG2cH , HG3d initial position detection region HG1e, HG2e, HG3e transition region HG1f, HG2f, HG3f transition region

Claims (7)

In the lens barrel that holds the lens movably in the optical axis direction,
A cylindrical member having a first engagement groove and a second engagement groove on the peripheral surface;
A moving frame that includes a first engagement piece that engages with the first engagement groove and a second engagement piece that engages with the second engagement groove, and holds the lens. Have
When the cylindrical member and the moving frame are relatively rotated, the first engaging piece moves along the first engaging groove, and the second engaging groove moves along the second engaging groove. When the second engagement piece moves, the lens is positioned in the optical axis direction,
The first engagement groove includes an eleventh groove portion that slides with a first frictional force with respect to the first engagement piece, and a first frictional force with respect to the first engagement piece. A twelfth groove that slides with a small second frictional force,
The second engagement groove includes a twenty-first groove portion that slides with a third frictional force with respect to the second engagement piece, and a third frictional force with respect to the second engagement piece. A 22nd groove that slides with a small fourth frictional force,
The timing at which the first engagement piece passes between the eleventh groove portion and the twelfth groove portion when the cylindrical member and the moving frame are relatively rotated is the second engagement piece. Is different from the timing of passing between the 21st groove portion and the 22nd groove portion.   2. The lens barrel according to claim 1, wherein when the photographing using the lens is performed, the engaging pieces move in the eleventh groove portion and the twenty-first groove portion, respectively. The twelfth groove portion is in contact with the eleventh groove portion, and slides with respect to the first engagement piece with a fifth friction force smaller than the first friction force and larger than the second friction force. Having a thirteenth groove,
The twenty-second groove portion is in contact with the twenty-first groove portion, and slides with respect to the second engagement piece with a sixth friction force smaller than the third friction force and larger than the fourth friction force. A 23rd groove,
When the cylindrical member and the moving frame are relatively rotated, the timing at which the first engagement piece passes between the thirteenth groove and the twelfth groove other than the thirteenth groove is 3. The lens barrel according to claim 1, wherein a timing at which the second engagement piece passes between the twenty-third groove portion and the twenty-second groove portion other than the twenty-third groove portion is different. The cylindrical member is provided with a third engagement groove on a peripheral surface thereof, and the moving frame is provided with a third engagement piece that slides in the third engagement groove,
The third engagement groove includes a thirty-first groove portion that slides with a seventh frictional force with respect to the third engagement piece, and a seventh frictional force with respect to the third engagement piece. A thirty-second groove portion that slides with a small eighth frictional force,
The timing at which the third engagement piece passes between the thirty-first groove portion and the thirty-second groove portion when the cylindrical member and the moving frame are relatively rotated is the first engagement piece. Is different from both the timing of passing between the eleventh groove portion and the twelfth groove portion and the timing of passing the second engagement piece between the twenty-first groove portion and the twenty-second groove portion,
The lens barrel according to claim 1, wherein the first engagement piece, the second engagement piece, and the third engagement piece are provided at substantially equal intervals in the circumferential direction.   5. The lens barrel according to claim 4, wherein when the photographing using the lens is performed, the engaging pieces move in the eleventh groove portion, the twenty-first groove portion, and the thirty-first groove portion, respectively. The twelfth groove portion is in contact with the eleventh groove portion, and slides with respect to the first engagement piece with a fifth friction force smaller than the first friction force and larger than the second friction force. Having a thirteenth groove,
The twenty-second groove portion is in contact with the twenty-first groove portion, and slides with respect to the second engagement piece with a sixth friction force smaller than the third friction force and larger than the fourth friction force. A 23rd groove,
The thirty-second groove portion is in contact with the thirty-first groove portion, and slides with respect to the third engagement piece with a ninth friction force that is smaller than the seventh friction force and larger than the eighth friction force. Having a 33rd groove,
A timing at which the first engagement piece passes between the thirteenth groove and the twelfth groove other than the thirteenth groove when the cylindrical member and the moving frame are relatively rotated; The timing at which the second engagement piece passes between the 23rd groove and the 22nd groove other than the 23rd groove, the third engagement piece other than the 33rd groove and the 33rd groove 6. The lens barrel according to claim 4, wherein the timing of passing through between the thirty-second thirty-second grooves is different.   The cylindrical member is provided with an impact reducing engagement groove on a peripheral surface thereof, and the moving frame is provided with an impact reducing engaging piece, and the cylindrical member and the moving frame are relatively rotated. Sometimes, the impact reducing engagement piece does not contact the impact reducing engagement groove, but when the lens barrel is given an impact, the impact reducing engagement groove is in the impact reducing engagement groove. The lens barrel according to claim 1, wherein the pieces come into contact with each other.

Images