JP2014048452A - Lens barrel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lens barrel which allows holding frame cam followers attached on lens holding frames to be engaged in holding frame cam grooves with a simple configuration, can be manufactured at low cost, and allows for using most suitable holding frame cam followers depending on the weight and the like of the lens holding frames.SOLUTION: A lens barrel includes first and second holding frame cam followers 4 attached on first and second lens holding frames, respectively, a first holding frame cam groove 21 having a first cam groove introducing groove 21b formed on a cam barrel 2, and a second holding frame cam groove 22 having a second cam groove introducing groove 22b formed on the cam barrel 2. The first cam groove introducing groove 21b and the second cam groove introducing groove 22b are configured such that a pitch distance therebetween equals to a pitch distance between the first holding frame cam follower 4 and the second holding frame cam follower 4 when the first lens holding frame and the second lens holding frame are positioned to abut each other along an optical axis.

Description

  The present invention relates to a lens barrel used for a still camera, a video camera, or the like.

  2. Description of the Related Art Conventionally, a lens barrel that is used in a still camera, a video camera, or the like and has a plurality of lens holding frames arranged on the inner peripheral side of a cam barrel so as to be arranged in the optical axis direction is known. In such a lens barrel provided with a plurality of lens holding frames, a plurality of holding frame cam grooves corresponding to the movable lens holding frames are formed on the inner surface of the cam barrel. A holding frame cam follower attached to each lens holding frame is engaged with the holding frame cam groove. However, the holding frame cam follower attached to each lens holding frame must be aligned and engaged with the holding frame cam groove, and the assembling operation is not easy.

  Therefore, for example, Patent Document 1 proposes a lens barrel in which the holding frame cam followers attached to the lens holding frames are easily aligned with the holding frame cam grooves. In the lens barrel proposed in Patent Document 1, the holding frame cam grooves have different groove widths, and the holding frame cam grooves are narrowed in order from the one end surface side in the axial direction of the cam cylinder. A holding frame cam follower having a diameter corresponding to the groove width of the holding frame cam groove is attached to each of the lens holding frames.

JP 2000-32476 A

  However, since the groove widths of the holding frame cam grooves in the lens barrel proposed in Patent Document 1 are different, the holding frame cam followers that engage with the holding frame cam grooves are used as the holding frame cam grooves. Accordingly, a plurality of types of holding frame cam followers having different diameters must be manufactured, which complicates the configuration and increases the manufacturing cost.

  In addition, since the diameter of the holding frame cam follower is determined according to the groove width of the holding frame cam groove, for example, even in the case of a lens holding frame in which a large lens group is held to increase the overall weight, the holding frame When the holding frame cam groove with which the cam follower is engaged is narrow, a holding frame cam follower having a small diameter must be used. For this reason, the lens holding frame having a large overall weight may be difficult to move smoothly. Furthermore, the cam follower with a larger diameter is more advantageous with respect to the cam follower falling off from the cam groove at the time of impact and the damage received by the cam groove. Therefore, the larger the weight of the holding frame, the larger the cam follower can be used. preferable.

  The present invention can easily assemble the holding frame cam follower attached to the lens holding frame with a simple configuration into the holding frame cam groove, and can be manufactured at low cost, and is optimal in accordance with the weight of the lens holding frame. An object of the present invention is to provide a lens barrel in which a cam follower for a holding frame having a large diameter can be used.

  In order to solve the above problems, a lens barrel of the present invention includes a lens holding frame that holds a lens group having one or a plurality of lenses, a holding frame cam follower disposed on an outer periphery of the lens holding frame, and the holding And a rotatable cam cylinder having a holding frame cam groove engaged with each of the leading ends of the frame cam follower, and the leading end of the holding frame cam follower is provided with the holding frame cam groove as the cam cylinder rotates. A lens barrel in which the lens holding frame moves in the optical axis direction by relatively moving the lens, and the lens holding frame is arranged in the optical axis direction in order on the inner peripheral side of the cam barrel. The holding frame cam follower includes a holding frame and a second lens holding frame, and the holding frame cam follower is arranged on the first lens holding frame and a second lens holding frame is arranged on the second lens holding frame. Cam follower for holding frame The holding frame cam groove includes a first holding frame cam groove that receives the tip of the first holding frame cam follower and a second holding frame that receives the tip of the second holding frame cam follower. Cam groove, and the first holding frame cam groove is provided with a first cam groove introducing groove on one end side thereof for introducing a leading end of the first holding frame cam follower, The holding frame cam groove is provided with a second cam groove introducing groove on one end side thereof for introducing the tip of the second holding frame cam follower, and the cam cylinder is formed of the first holding frame cam follower. A front end portion is incorporated into the first cam groove introduction groove, and a front end portion of the second holding frame cam follower is provided for incorporation into the second cam groove introduction groove. The first cam groove introduction groove and the one end face in the axial direction of the cam cylinder The first cam groove introducing groove and the second cam groove introducing groove are extended so as to communicate with the second cam groove introducing groove, and the pitch distance between the first cam groove introducing groove and the second cam groove introducing groove is the first lens holding frame and the second lens. The first holding frame cam follower and the second holding frame cam follower are configured to coincide with a pitch distance in a contact state in which the holding frame is in contact with the optical axis direction. Here, the term “matching” includes the case of perfect matching and the case of matching substantially within the range of dimensional tolerance.

  According to this configuration, for example, after the first holding frame cam follower disposed on the first lens holding frame is inserted into the assembling groove from the one end surface side of the cam cylinder and aligned with the first cam groove introducing groove, The second holding frame cam follower disposed on the second lens holding frame is inserted into the assembling groove from one end surface side of the cam cylinder, and the first lens holding frame and the second lens holding frame are brought into contact with each other.

  At that time, the pitch distance between the first cam groove introducing groove and the second cam groove introducing groove is such that the first holding frame cam follower and the second holding frame are in contact with each other. Since the second lens holding frame and the second lens holding frame are in contact with each other, the second holding frame cam follower is introduced into the second cam groove because the pitch distance between the second lens holding frame and the frame cam follower is the same. Naturally aligned with the groove.

  Accordingly, the first holding frame cam follower and the second holding frame cam follower can be easily introduced and incorporated into the first cam groove introduction groove and the second cam groove introduction groove, respectively.

  Thus, for example, the first cam groove introduction groove and the second cam groove introduction groove are formed to have the same groove width, and the first holding frame cam follower and the second holding frame cam follower have the same configuration and the same diameter. It can also be used, can be configured simply, and can be manufactured at low cost.

  In another aspect, in the lens barrel, the second holding frame cam groove communicates with the second cam groove introducing groove, and a distal end portion of the second holding frame cam follower relatively moves during photographing. The second cam groove introduction groove has a wider portion than the second cam groove photographing area groove, and the second cam groove introduction groove includes: It is arranged between the one end face and the cam groove introduction groove.

  According to this configuration, since the second cam groove introduction groove has a wider portion than the second cam groove photographing region groove, the second holding frame cam follower introduces the second cam groove. Even when the second holding frame cam follower and the second cam groove introducing groove are slightly misaligned due to a manufacturing error or the like during the alignment operation with the groove, the second holding frame cam follower can be easily attached to the second holding frame cam follower. Can be introduced into the cam groove introduction groove.

  In another aspect, in any one of the lens barrels described above, the second holding frame cam groove communicates with the second cam groove introduction groove, and a tip portion of the second holding frame cam follower is at the time of photographing. A second cam groove shooting area groove that moves relatively is provided, and the second cam groove introduction groove includes a tapered portion whose groove width gradually decreases toward the second cam groove shooting area groove. The groove introduction groove is disposed between the one end surface and the cam groove introduction groove.

  According to this configuration, the second cam groove introduction groove includes the tapered portion whose groove width gradually narrows toward the second cam groove photographing region groove side, so that the second holding frame cam follower is formed by the tapered portion. It can be guided and introduced into the shooting area groove for two cam grooves. Therefore, for example, when the second holding frame cam follower is aligned with the second cam groove introducing groove, the second holding frame cam follower and the second cam groove introducing groove are slightly displaced due to manufacturing errors or the like. Even in such a case, the second holding frame cam follower can be easily introduced into the second cam groove introduction groove.

  In another aspect, in any one of the lens barrels described above, the first holding frame cam groove communicates with the first cam groove introduction groove, and a tip portion of the first holding frame cam follower is at the time of photographing. A first cam groove shooting area groove that moves relatively is provided, and the second holding frame cam groove communicates with the second cam groove introduction groove, and the distal end portion of the second holding frame cam follower moves relatively during shooting. A second cam groove photographing region groove, and the second cam groove introducing groove is disposed between the one end face and the first cam groove introducing groove, and the incorporating groove and the second cam groove. The cam groove introduction groove and the first cam groove photographing area groove are formed so that the groove width is wider than that of the second cam groove photographing area groove.

  According to this configuration, the first holding frame cam follower that is inserted into the assembling groove before the second holding frame cam follower can be made larger in diameter than the second holding frame cam follower. As a result, the first lens holding frame on which the first holding frame cam follower is arranged can move smoothly with a larger weight than the second lens holding frame on which the second holding frame cam follower is arranged.

  Furthermore, the cam follower with a larger diameter is more advantageous with respect to the cam follower falling off from the cam groove at the time of impact and the damage received by the cam groove. Therefore, the larger the weight of the holding frame, the larger the cam follower can be used. .

  The lens barrel of the present invention can be easily assembled with the cam groove for the holding frame attached to the lens holding frame with a simple configuration and can be manufactured at a low cost, and the weight of the lens holding frame, etc. The cam follower for the holding frame with the optimum diameter can be used.

It is sectional drawing of one Embodiment of the lens-barrel of this invention. It is a disassembled perspective view of the principal part of FIG. It is the III-III line expanded sectional view of FIG. It is the IV-IV line expanded sectional view of FIG. It is an enlarged view of the principal part of FIG. It is the perspective view to which the cam cylinder used for the lens barrel shown in FIG. 1 was expanded. It is explanatory drawing represented by making the inner peripheral surface of a cam cylinder into a deployment state. It is an expansion perspective view of the 1st lens holding frame used for the lens barrel shown in FIG. (A) is the perspective view seen from the front side of the 1st lens holding frame of the state which assembled | attached the cam follower for holding frames used for the lens barrel shown in FIG. 1, (b) is the front view, (c ) Is a perspective view seen from the rear side. (A) is the perspective view seen from the front side of the 1st lens holding frame of the state supported by the guide shaft used for the lens barrel shown in FIG. 1, (b) is the front view, (c) These are the perspective views seen from the back side. It is an expansion perspective view of the 2nd lens holding frame used for the lens barrel shown in FIG. (A) is the perspective view seen from the front side of the non-contact state of the 1st lens holding frame and the 2nd lens holding frame, (b) is the perspective view seen from the back side of the non-contact state. is there. (A) is a side view of the contact state between the first lens holding frame and the second lens holding frame, (b) is a perspective view seen from the front side, and (c) is FIG. 13 (b). It is the perspective view seen from the front side of a different angle. It is a perspective view of the light-shielding member used for the lens barrel shown in FIG. It is sectional drawing of the state in which the light shielding member, the 1st lens holding frame, and the 2nd lens holding frame each entered the introduction groove | channel. FIG. 16 is a cross-sectional view showing a state where the light shielding member, the first lens holding frame, and the second lens holding frame are moved forward from the state of FIG. 15 by rotation of the cam cylinder. It is explanatory drawing showing each movement locus | trajectory of a light-shielding member, a 1st lens holding frame, and a 2nd lens holding frame. It is explanatory drawing which expressed the inner peripheral surface of the cam cylinder which has the cam groove for 2nd holding frames of other embodiment in the unfolded state.

  Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. 1 is a cross-sectional view of an embodiment of a lens barrel of the present invention, FIG. 2 is an exploded perspective view of the main part of FIG. 1, and FIG. 3 is an enlarged cross-sectional view taken along line III-III of FIG. 4 is an enlarged sectional view taken along the line IV-IV in FIG. 1, FIG. 5 is an enlarged view of the main part of FIG. 1, and FIG. 6 is an enlarged perspective view of the cam cylinder. 1, 2, and 5 to 20, the X direction is the front side, and the Y direction is the rear side.

  The lens barrel 10 of the present embodiment includes a lens barrel body 1, a cam barrel 2, a first lens holding frame 31 to a seventh lens holding frame 37, a first lens holding frame 31 and a second lens holding frame 32. A holding frame cam follower 4 held, a light shielding member 5, and a light shielding member cam follower 6 held by the light shielding member 5 are provided.

  The lens barrel body 1 includes a cylindrical fixed tube 11 and guide shafts 12 a and 12 b disposed on the inner peripheral side of the fixed tube 11. The axis of the fixed cylinder 11 is set to coincide with the optical axis O.

  In this embodiment, the guide shafts 12 a and 12 b include a first guide shaft 12 a and a first guide shaft 12 a and a second guide shaft 12 b disposed with a distance in the circumferential direction of the fixed cylinder 11. The first guide shaft 12a and the second guide shaft 12b have the same configuration, and each is fixedly held in the fixed cylinder 11 so that the axial direction extends along the direction of the optical axis O. Has been.

  Further, the lens barrel body 1 includes a cylindrical cam operation ring 15 disposed on the outer peripheral side of the fixed tube 11 so as to be rotatable with respect to the fixed tube 11. The lens barrel body 1 includes a mount 13 on the rear end side (image side), and is attached to a camera body (not shown) via the mount 13. In this embodiment, a cylindrical hood 14 is detachably attached to the front end side (object side) of the lens barrel body 1.

  As shown in FIG. 6, the cam cylinder 2 is formed of a cylindrical body. The cam cylinder 2 has long groove-like cam grooves 21 to 24 formed on its inner peripheral surface so as to be cut at a predetermined depth radially outward from the inner peripheral surface and recessed along a predetermined direction. It has.

  As shown in FIG. 7, the cam groove of this embodiment includes holding frame cam grooves 21, 22, a light shielding member cam groove 23, and a mounting groove 24. In this embodiment, the holding frame cam grooves 21, 22, the light shielding member cam grooves 23, and the assembling grooves 24 are arranged on the inner peripheral surface of the cam cylinder 2 in three circumferential directions (ZW direction). It is installed.

  Each holding frame cam groove is composed of a first holding frame cam groove 21 and a second holding frame cam groove 22. The first holding frame cam groove 21 includes a first cam groove shooting area groove 21a in which the distal end of the holding frame cam follower 4 relatively moves during shooting, and a start end side of the first cam groove shooting area groove 21a ( And a first cam groove introduction groove 21b disposed on one end side.

  The first cam groove photographing region groove 21a and the first cam groove introducing groove 21b are formed in a trapezoidal cross section that gradually decreases in width radially outward as shown in FIGS.

  As shown in FIG. 7, the second holding frame cam groove 22 is for the second cam groove in which the distal end portion of the holding frame cam follower 4 to be described later moves relative to the camera as in the case of the first holding frame cam groove 21. An imaging region groove 22a and a second cam groove introduction groove 22b disposed on the start end side of the second cam groove imaging region groove 22a are provided.

  The second cam groove introduction groove 22b includes a wide portion 22c, and a tapered portion 22d disposed between the wide portion 22c and the second cam groove photographing region groove 22a.

  The wide portion 22c is formed so that the groove width is wider than the groove width of the second cam groove imaging region groove 22a. The tapered portion 22d is formed such that the groove width gradually decreases from the wide portion 22c to the second cam groove imaging region groove 22a.

  Each light shielding member cam groove 23 is for a light shielding member disposed on the start end side of the light shielding member photographing region groove 23a in which the distal end portion of the light shielding member cam follower 6 relatively moves during photographing and the light shielding member photographing region groove 23a. And an introduction groove 23b.

  The light-shielding member photographing area groove 23a extends in the axial direction (front-rear direction, X in the drawing) of the first holding frame cam groove 21 and the second cam groove photographing area groove 22a from the start end to the end. (Y direction) distance is changed.

  Specifically, the axial distance L11 is maximized at the intermediate portion between the light-shielding member photographing region groove 23a and the second cam groove photographing region groove 22a, and the shafts between the end portions in the longitudinal direction are maximum. The direction distances L12 and L13 are smaller than the distance L11.

  Further, the light-shielding member photographing region groove 23a and the light-shielding member introduction groove 23b are also formed in a trapezoidal shape that gradually narrows radially outward as shown in FIGS. The light-shielding member photographing region groove 23 a and the light-shielding member introduction groove 23 b are formed narrower than the first holding frame cam groove 21.

  The mounting groove 24 includes a holding frame mounting groove 24a and a light shielding member mounting groove 24b.

  The holding frame mounting groove 24 a includes an opening 24 c in the rear end surface 2 a of the cam cylinder 2. The holding frame mounting groove 24 a extends from the opening 24 c in the axial direction of the cam cylinder 2, and the second cam groove introducing groove 22 b and the first holding frame cam groove 21 of the second holding frame cam groove 22. The first cam groove introduction groove 21b communicates with the first cam groove introduction groove 21b.

  Further, the groove width of the holding frame incorporating groove 24 a is set to be approximately the same as the groove width of the first cam groove introducing groove 21 b of the first holding frame cam groove 21.

  The light shielding member incorporation groove 24b extends in the axial direction from the holding frame incorporation groove 24a to the light shielding member introduction groove 23b, and communicates with the light shielding member introduction groove 23b of the light shielding member cam groove 23.

  The groove width of the light shielding member mounting groove 24b is narrower than the groove width of the holding frame mounting groove 24a, and is formed so that the holding frame cam follower 4 cannot enter.

  As shown in FIG. 1, the cam cylinder 2 configured in this manner is disposed on the inner peripheral side of the fixed cylinder 11 and on the radially outer side of the guide shafts 12a and 12b so as to be rotatable with respect to the fixed cylinder 11. Has been. The cam cylinder 2 is non-rotatably connected to the cam operation ring 15 by the interlocking pin 16, and the cam cylinder 2 is rotated together by the rotation operation of the cam operation ring 15.

  Next, the lens holding frames 31 to 37 will be described. The lens holding frame holds the lens group 100, and in this embodiment, the lens holding frame includes seven lenses from the first lens holding frame 31 to the seventh lens holding frame 37. The lens group 100 held by the first lens holding frame 31 to the seventh lens holding frame 37 includes one or a plurality of lenses.

  As shown in FIG. 8, the first lens holding frame 31 is formed of a substantially cylindrical shape, and includes a lens holding portion 31 f that holds the lens group 100 on the inner peripheral side.

  Further, as shown in FIG. 3, the first lens holding frame 31 includes cam follower holding portions 7 a and 7 b that hold the holding frame cam follower 4 on the outer peripheral side thereof.

  The cam follower holding part includes one main cam follower holding part 7 a and two sub cam follower holding parts 7 b arranged at substantially equal intervals along the circumferential direction of the first lens holding frame 31.

  In this embodiment, the main cam follower holding portion 7a is disposed on the lower left side in FIG. 3 and is formed of a cylindrical shape. The base end portion of the holding frame cam follower 4 is disposed inside the first lens holding frame 31. A main cam follower storage portion 71a movably stored in the radial direction of the cam cylinder 2; and a coil spring 71b as a biasing member that biases the holding frame cam follower 4 stored in the main cam follower storage portion 71a. Yes.

  The coil spring 71 b is housed in the main cam follower housing portion 71 a together with the base end portion of the holding frame cam follower 4, and biases the holding frame cam follower 4 outward in the radial direction of the first lens holding frame 31.

  Similar to the main cam follower holding portion 7a, the sub cam follower holding portion 7b is formed in a cylindrical shape, and includes a sub cam follower storage portion 72a in which the base end portion of the holding frame cam follower 4 is stored.

  However, the sub cam follower storage portion 72a stores only the base end portion of the holding frame cam follower 4, and the coil spring 71b is not stored like the main cam follower storage portion 71a. Accordingly, the holding frame cam follower 4 housed in the sub cam follower housing portion 72 a is not biased outward in the radial direction of the first lens holding frame 31.

  Here, the holding frame cam follower 4 held in each of the main cam follower holding portion 7a and the sub cam follower holding portion 7b will be described. The holding frame cam followers 4 are provided with a total of six pieces: three pieces engaged with the first lens holding frame 31 and three pieces engaged with the second lens holding frame 32.

  These all have the same configuration, and each of the holding frame cam followers 4 has a substantially columnar shape. As shown in FIGS. A cam groove engaging portion 41 is provided. The cam groove engaging portion 41 is formed in a truncated cone shape that gradually decreases in diameter toward the tip.

  Each holding frame cam follower 4 includes a fitting insertion portion 42 at the base end. Then, the insertion frame 42 is inserted into the insertion hole 73 provided in the sub cam follower holding portion 7b from the side of the sub cam follower storage portion 72a, whereby the holding frame cam follower 4 is held by the sub cam follower holding portion 7b. Has been.

  Similarly, the main cam follower holding portion 7a is inserted by inserting the fitting insertion portion 42 of the holding frame cam follower 4 into the fitting insertion hole 73 provided in the main cam follower holding portion 7a from the main cam follower storage portion 71a side. The holding frame cam follower 4 is held on the frame. In this state, the holding frame cam follower 4 is movable in the radial direction of the first lens holding frame 31 by the main cam follower holding portion 7a.

  The holding frame cam follower 4 held by the main cam follower holding portion 7a is urged radially outward of the first lens holding frame 31 by a coil spring 71b stored in the main cam follower storage portion 71a.

  Returning to FIG. 8, the description of the first lens holding frame 31 will be continued. The first lens holding frame 31 includes supported portions 31a and 31b supported by guide shafts 12a and 12b on the outer peripheral portion. The supported portion of this embodiment includes a main supported portion 31a (shown on the lower side in FIG. 8) supported by the second guide shaft 12a and a sub supported portion supported by the first guide shaft 12b. 31b (shown on the upper side in FIG. 8).

  In this embodiment, the main supported portion 31a has a predetermined length from the front surface to the rear side of the disc portion 31c provided on the first lens holding frame 31, and is cylindrical on the radially outer portion of the disc portion 31c. And a guide shaft fitting insertion hole 31d into which the second guide shaft 12b is fitted.

  Further, as shown in FIG. 3, the main supported portion 31a is disposed in the vicinity of the main cam follower holding portion 7a between the main cam follower holding portion 7a and the sub cam follower holding portion 7b. The pitch distance L21 in the circumferential direction with respect to 7a is a position that is shorter than the pitch distance L22 in the circumferential direction with respect to the adjacent sub cam follower holding portion 7b.

  As shown in FIGS. 8 and 9, the sub supported portion 31b includes a guide shaft fitting insertion hole 31e through which the first guide shaft 12a is inserted. The guide shaft insertion hole 31e is formed so as to penetrate from the front surface to the rear surface of the disc portion 31c. Therefore, the axial length L32 of the sub supported portion 31b (shown in FIG. 9A) is shorter than the axial length L31 of the main supported portion 31a (shown in FIG. 8).

  Further, the guide shaft fitting insertion hole 31e of this embodiment has a distance in the circumferential direction of the disc portion 31c substantially the same as the diameter of the first guide shaft 12a, and a length in the radial direction of the disc portion 31c. It is formed in a long hole shape longer than the diameter of the shaft 12a.

  Further, the first lens holding frame 31 includes a first lens holding frame contact portion 31h that contacts the second lens holding frame 32 on the rear side of the main cam follower holding portion 7a and the sub cam follower holding portion 7b.

  The first lens holding frame 31 has a connection groove 31i for connecting to the light shielding member 5 and a receiving portion 31j for receiving a connection portion support piece 54 which is a part of the light shielding member 5 described later on the outer periphery. I have.

  The connection grooves 31 i are provided with three arranged at equal intervals in the circumferential direction of the first lens holding frame 31. In this embodiment, the connecting groove 31i is disposed on the front side of each of the main cam follower holding portion 7a and the sub cam follower holding portion 7b, and has a predetermined width and a predetermined depth from the outer peripheral surface. It is formed so as to be recessed inward in the direction.

  The receiving portion 31j has the same width as the connection groove 31i and is formed to be recessed from the front surface of the disk portion 31c to the rear side at a predetermined depth so as to communicate with each of the connection grooves 31i.

  In the first lens holding frame 31 configured as described above, with the holding frame cam follower 4 being held, the first guide shaft 12a is inserted into the guide shaft fitting insertion hole 31d of the sub supported portion 31b as shown in FIG. While being inserted, the second guide shaft 12b is inserted into the guide shaft fitting insertion hole 31e of the main supported portion 31a and supported by the second guide shaft 12b and the first guide shaft 12a. As shown, the cam cylinder 2 is disposed on the inner peripheral side so as to be movable in the axial direction. In this state, the holding frame cam followers 4 enter the first holding frame cam grooves 21, respectively.

  In this state, as shown in FIG. 3, the cam follower 4 for the holding frame held by the main cam follower holding portion 7a has the cam groove engaging portion 41 formed by the urging force of the coil spring 71b. It is in the state pressed against the inner surface of 21. On the other hand, in the holding frame cam follower 4 held by the sub cam follower holding portion 7b, the cam groove engaging portion 41 is not in contact with the inner side surface of the first holding frame cam groove 21, so that the cam groove engaging portion There is a clearance between 41 and the inner surface of the first holding frame cam groove 21.

  Next, the second lens holding frame 32 will be described. As shown in FIG. 11, the second lens holding frame 32 includes a lens holding portion 32 f that holds the lens group on the inner peripheral side. Similarly to the first lens holding frame 31, the second lens holding frame 32 includes cam follower holding portions 8 a and 8 b that hold holding frame cam followers on the outer peripheral side thereof.

  As shown in FIGS. 4 and 8, the cam follower holding portion of the second lens holding frame 32 has one main cam follower holding portion 8a (see FIG. 8) disposed at substantially equal intervals along the circumferential direction of the second lens holding frame 32. 4) and two sub cam follower holding portions 8b.

  The main cam follower holding part 8a and the sub cam follower holding part 8b have substantially the same configuration as the main cam follower holding part 7a and the sub cam follower holding part 7b of the first lens holding frame 31, respectively.

  Specifically, the main cam follower holding portion 8a includes a main cam follower storage portion 81a in which the base end portion of the holding frame cam follower 4 is movably stored in the radial direction of the second lens holding frame 32, as shown in FIG. A coil spring 81b.

  The sub cam follower holding portion 8b includes a sub cam follower storage portion 82 in which only the base end portion of the holding frame cam follower 4 is stored.

  The holding frame cam follower 4 is held by the main cam follower holding portion 8a and the sub cam follower holding portion 8b in the same manner as the cam follower holding portions 7a and 7b of the first lens holding frame 31.

  The second lens holding frame 32 includes supported portions 32a and 32b supported by the guide shafts 12a and 12b between the main cam follower holding portion 8a and the sub cam follower holding portion 8b in the outer peripheral portion. The supported portion in the second lens holding frame 32 includes a main supported portion 32a supported by the first guide shaft 12a and a sub supported portion 32b supported by the second guide shaft 12b.

  As shown in FIG. 11, the main supported portion 32 a is a cylinder having a protruding portion that protrudes from the front surface of the second lens holding frame 32 to the front side with a predetermined length on the radially outer side of the second lens holding frame 32. It is formed in a shape and includes a guide shaft insertion hole 32d into which the first guide shaft 12a is inserted.

  Further, as shown in FIG. 4, the main supported portion 32a is located at a position where the circumferential pitch distance L41 with the main cam follower holding portion 8a is shorter than the circumferential pitch distance L42 with the adjacent sub cam follower holding portion 8b. And is disposed in the vicinity of the main cam follower holding portion 8a.

  As shown in FIG. 11, the sub supported portion 32b is formed of a cylindrical body having a guide shaft fitting insertion hole 32e through which the second guide shaft 12b is inserted. The sub-supported portion 32b has an axial length L34 that is shorter than the axial length L33 of the main supported portion 41a.

  In addition, although the guide shaft fitting insertion hole 32e of this embodiment is not illustrated, the circumferential distance of the second lens holding frame 32 is substantially the same as the diameter of the second guide shaft 12b, and the diameter of the second lens holding frame 32 is not shown. The length in the direction is formed in a long hole shape longer than the diameter of the second guide shaft 12b.

  Further, as shown in FIGS. 11 to 13, the second lens holding frame 32 is disposed on the front side of the main cam follower holding portion 8 a and the sub cam follower holding portion 8 b, and is applied to the first lens holding frame 31 of the first lens holding frame 31. A second lens holding frame contact portion 32h that contacts the contact portion 31h is provided.

  These second lens holding frame contact portions 32h are in contact with the first lens holding frame contact portions 31h, as shown in FIG. The pitch distance L51 between the holding frame cam followers held by the first and second holding frame cam grooves 21 in the cam cylinder 2 is equal to the first cam groove introducing groove 21b and the second holding frame cam groove 22 in the cam cylinder 2. The pitch distance L52 (shown in FIG. 7) with the two cam groove introduction groove 22b is set to be the same.

  Then, as shown in FIG. 4, like the first lens holding frame 31, the fitting insertion portion 42 of the holding frame cam follower 4 is fitted into the fitting insertion hole 83 provided in the main cam follower holding portion 8a. The holding frame cam follower 4 is held by the main cam follower holding portion 8a so as to be movable in the radial direction of the second lens holding frame 32, and is urged outward in the radial direction of the second lens holding frame 32 by the coil spring 81b. .

  Further, the holding frame cam follower 4 is held by the sub cam follower holding portion 7b by fitting the fitting insertion portion 42 of the holding frame cam follower 4 into the fitting hole 83 provided in the sub cam follower holding portion 8b.

  The second lens holding frame 32 holding the holding frame cam follower 4 has the first guide shaft 12a inserted through the guide shaft fitting insertion hole 32d of the main supported portion 32a as shown in FIGS. As shown in FIG. 1, the second guide shaft 12b is inserted into the guide shaft fitting insertion hole 32e of the sub supported portion 32b and supported by the first guide shaft 12a and the second guide shaft 12b. It is arranged on the inner peripheral side of the tube 2 and behind the first lens holding frame 31 so as to be movable in the axial direction.

  In this state, the holding frame cam followers 4 held by the second lens holding frame 32 respectively enter the second holding frame cam grooves 22.

  In this state, the cam follower 4 for holding frame held by the main cam follower holding portion 8a is pressed against the inner surface of the second holding frame cam groove 22 by the biasing force of the coil spring 81b. It is in the state that was. On the other hand, in the holding frame cam follower 4 held by the sub cam follower holding portion 8b, the cam groove engaging portion 41 is not in contact with the inner side surface of the second holding frame cam groove 22, so that the cam groove engaging portion A clearance is formed between 41 and the inner surface of the second holding frame cam groove 22.

  Further, as shown in FIG. 5, the main cam follower holding portion 8a of the second lens holding frame 32 is aligned with the sub cam follower holding portion 7b of the first lens holding frame 31 in the optical axis direction and is used for the holding frame held by them. Cam followers 4 are arranged in the optical axis direction. The main cam follower holding portion 7a of the first lens holding frame 31 is aligned with the sub cam follower holding portion 8b of the second lens holding frame 32 in the optical axis direction, and the holding frame cam follower 4 held by them is arranged in the optical axis direction. Are lined up.

  Next, the third lens holding frame 33 will be described. The third lens holding frame 33 is supported by two focus guide shafts 33a (shown in FIG. 2) fixedly provided on the second lens holding frame 32 so as to be movable in the axial direction. As shown in FIG. 3, the second lens holding frame 32 is disposed on the front side.

  The third lens holding frame 33 is moved in the front-rear direction with respect to the second lens holding frame 32 by a driving motor 33b (shown in FIG. 2) provided in the lens barrel body 1.

  Next, the fourth lens holding frame 34 to the seventh lens holding frame 37 will be described. As shown in FIG. 1, the fourth lens holding frame 34 is disposed on the front side of the first lens holding frame 31 in the barrel body 1 so as not to move.

  The fifth lens holding frame 35 to the seventh lens holding frame 37 are arranged so as to be immovable so as to be sequentially arranged on the rear side of the second lens holding frame 31 in the barrel body 1.

  Next, the light shielding member 5 will be described. The light shielding member 5 of this embodiment includes a light shielding member main body 51 and connecting portions 55a to 55c as shown in FIG.

  The light shielding member main body 51 includes a disc portion 52 disposed on the front end side, a cylindrical portion 53 disposed on the rear side of the disc portion 52, and a connecting portion support piece 54 that supports the connecting portions 55a to 55c. It has.

  The disc portion 52 has an outer diameter that is substantially the same as the outer diameter of the lens group 100 held by the first lens holding frame 31. The disc portion 52 is disposed on the front side of the lens group 100 held by the first lens holding frame 31 as shown in FIGS.

  The cylindrical portion 53 is formed on the inner peripheral side so that the front side of the lens group 100 held by the first lens holding frame 31 can enter.

  The connecting portion support pieces 54 are provided with three pieces arranged at equal intervals in the circumferential direction of the cylindrical portion 53. Each connecting portion support piece 54 has a width that can enter the receiving portion 31 j of the first lens holding frame 31 and is formed so as to protrude radially outward from the rear end of the cylindrical portion 53.

  The connecting portion includes three (a plurality) of first to third connecting portions 55 a to 55 c supported by the connecting portion support pieces 54. Each connection part 55a-55c is comprised from the thing of rectangular plate shape, and is protrudingly provided from the front-end | tip of the connection part support piece 54 to the back side.

  And these connection parts 55a-55c are inserted in each of the connection groove | channel 31i of the 1st lens holding frame 31 so that a movement is possible. Further, the clearance between both of the three connecting portions 55a and the connecting groove 31i is between the two connecting portions 55b and 55c and the connecting groove 31i. It is formed to be smaller than the clearance.

  In this embodiment, all three connecting grooves 31i are formed to have the same width L10 (shown in FIG. 8). On the other hand, the width L9 of the first connecting portion 55a on the upper side in FIG. 14 is slightly larger than the width L8 of the other two second connecting portions 55b and the third connecting portion 55c. The clearance between the insertion state of the connection groove 31i is the clearance between the second connection portion 55b and the connection groove 31i and the insertion state of the third connection portion 55c and the connection groove 31i. It is set to be smaller than the clearance between the two.

  With this configuration, the first connecting portion 55a and the connecting groove 31i can reliably move the light blocking member 5 in the axial direction without rotating with respect to the first lens holding frame 31, while the second The connection portions 55b and the third connection portions 55c and the connection grooves 31i can prevent the entire connection portions 55a to 55c and the connection grooves 31i from being over-constrained due to manufacturing errors or the like. As a result, the entire connecting portions 55a to 55c can be easily fitted into the connecting groove 31i and assembled, and the light shielding member 5 can move smoothly with respect to the first lens holding frame 31 after assembly.

  Further, in this embodiment, the light shielding member main body 51 and the connecting portions 55a to 55c are simultaneously formed of synthetic resin by integral molding.

  The light shielding member cam followers 6 are disposed on the outer surfaces of the connecting portions 55a to 55c, and the light shielding member cam followers 6 are formed so as to protrude radially outward from the outer surfaces of the connecting portions 55a to 55c. Yes.

  Each light shielding member cam follower 6 is formed in a substantially conical shape that gradually decreases in diameter toward the outside in the radial direction so that it can enter and engage with the light shielding member cam groove 23 of the cam cylinder 2. In this embodiment, the cam follower 6 for the light shielding member is formed simultaneously with the light shielding member 5 by integral molding. In this embodiment, each light shielding member cam follower 6 is formed in a shape in which a part of a cone is cut so as to be easily manufactured.

  Next, a case where the first lens holding frame 31, the second lens holding frame 32, and the light shielding member are engaged with the cam groove of the cam cylinder 2 configured as described above will be described.

  First, as shown in FIG. 7, the light shielding member cam follower 6 attached to the light shielding member 5 is inserted into the assembling groove 24 of the cam cylinder 2 from the opening 24 c. As a result, the light shielding member cam follower 6 enters the light shielding member incorporation groove 24b from the holding frame incorporation groove 24a and further enters the front end position of the light shielding member incorporation groove 24b (a position where the light shielding member cam follower 6 is indicated by hatching). .

  Next, the second guide shaft 12b is inserted into the main supported portion 31a of the first lens holding frame 31 and the first guide shaft 12a is inserted into the sub supported portion 31b, respectively, and is held by the first lens holding frame 31. The holding frame cam follower (first holding frame cam follower) 4 is inserted into the mounting groove 24 of the cam cylinder 2 from the opening 24 c.

  As a result, the holding frame cam follower 4 enters the holding frame mounting groove 24 a forward, and accordingly, the connecting portions 55 a to 55 c of the light shielding member 5 are inserted into the connecting groove 31 i of the first lens holding frame 31. Both enter and connect.

  Then, as shown in FIG. 7, when the holding frame cam follower 4 reaches the front end position of the holding frame mounting groove 24a (the position indicated by the hatching of the holding frame cam follower 4), the holding frame cam follower 4 becomes the light blocking member mounting groove. Since it is formed larger in diameter than the groove width of 24b, the holding frame cam follower 4 stops at the front end position of the holding frame mounting groove 24a.

  Next, the first guide shaft 12a is inserted into the main supported portion 32a of the second lens holding frame 32, and the second guide shaft 12b is inserted into the sub supported portion 32b, and the second lens holding frame 32 is held. The holding frame cam follower (second holding frame cam follower) 4 is inserted into the mounting groove 24 of the cam cylinder 2 from the opening 24c. In this state, as shown in FIG. 12, the second lens holding frame contact portion 32 h of the second lens holding frame 32 and the first lens holding frame contact portion 31 h of the first lens holding frame 31 face each other.

  When the holding frame cam follower 4 enters the holding frame mounting groove 24a, the second lens holding frame abutting portion 32h of the second lens holding frame 32 and the first lens holding frame 31 as shown in FIG. The first lens holding frame contact portion 31h contacts.

  In this abutting state, the holding frame cam follower 4 held by the second lens holding frame 32 has a front and rear position that is the same as the second cam groove introduction groove 22b of the second holding frame cam groove 22 as shown in FIG. It comes to the coincident position (position where the holding frame cam follower 4 is hatched).

  Accordingly, in this state, the cam follower 6 for the light shielding member, the cam follower 4 for the holding frame held by the first lens holding frame 31, and the cam follower 4 for the holding frame held by the second lens holding frame 32 are introduced for the light shielding member, respectively. The groove 23b, the first cam groove introduction groove 21b, and the second cam groove introduction groove 22b are opposed to each other in the circumferential direction.

  Then, the cam cylinder 2 is rotated from this state. Accordingly, the light shielding member cam follower 6, the holding frame cam follower 4 held by the first lens holding frame 31, and the holding frame cam follower 4 held by the second lens holding frame 32 are respectively provided with the light shielding member introduction groove 23b, Each of the first cam groove introduction groove 21b and the second cam groove introduction groove 22b can be inserted.

  At that time, the cam follower 4 for holding frame held by the main cam follower holding portions 7a and 8a has the cam groove engaging portion 41 by the urging force of the coil springs 71b and 81b so that the cam groove engaging portion 41 has the first holding frame cam groove 21 and the second holding frame. On the other hand, the holding frame cam follower 4 held by the sub cam follower holding portions 7b, 8b is in a state of contacting the inner surface of the cam groove 22, and the cam groove engaging portion 41 has the first holding frame cam groove 21. The second holding frame cam groove 22 is not in contact with the inner surface. Accordingly, the holding frame cam followers 4 held by the main cam follower holding portions 7a and 8a are easily introduced into the second cam groove introduction grooves 22b, respectively.

  In addition, since the second cam groove introduction groove 22b has a wide portion 22c, the holding frame cam follower 4 held by the second lens holding frame 32 is slightly different from the second cam groove introduction groove 22b. Even if it is shifted, it is reliably introduced into the second cam groove introduction groove 22b.

  Further, when the cam cylinder 2 rotates, the cam follower 6 for the light shielding member, the cam follower 4 for the holding frame held by the first lens holding frame 31, and the cam follower 4 for the holding frame held by the second lens holding frame 32 are introduced into the introduction groove 23b. , 21b, 22b can enter and engage with the light-shielding member photographing region groove 23a, the first cam groove photographing region groove 21a, and the second cam groove photographing region groove 22a (see FIG. 15).

  Also in this case, since the second cam groove introduction groove 22b includes the tapered portion 22d, the holding frame cam follower 4 held by the second lens holding frame 32 is moved from the wide portion 22c to the second cam groove. Can be smoothly inserted into the photographing region groove 22a.

  Next, the operation of the lens barrel 10 of the present invention will be described. For example, when the cam operating ring 15 is rotated from the state shown in FIG. 15, the cam cylinder 2 rotates. Along with the rotation, the light shielding member cam follower 6, the holding frame cam follower 4 held by the first lens holding frame 31, and the holding frame cam follower 4 held by the second lens holding frame 32 respectively. It moves relative to the front side along each of the groove 23a, the first cam groove shooting area groove 21a, and the second cam groove shooting area groove 22a.

  At that time, the cam groove engaging portion 41 of the holding frame cam follower 4 held by the main cam follower holding portions 7a and 8a presses against the inner surfaces of the first holding frame cam groove 21 and the second holding frame cam groove 22. On the other hand, the cam groove engaging portion 41 of the holding frame cam follower 4 held by the sub cam follower holding portions 7b and 8b is within the first holding frame cam groove 21 and the second holding frame cam groove 22. It is in a non-contact state with the side surface and smoothly moves relatively.

  In the relative movement, each of the light blocking member 5, the first lens holding frame 31, and the second lens holding frame 32 moves to the front side as shown in FIG. At this time, the light shielding member 5 is positioned at the intermediate position of the light shielding member photographing region groove 23a in accordance with the axial distance between the light shielding member photographing region groove 23a and the first cam groove photographing region groove 21a. The distance L11 in the axial direction with respect to the holding frame 31 is maximized, and the distances L12 and L13 in the axial direction of both are gradually decreased as the end position (tele position, wide position) is reached.

  More specifically, as shown in FIG. 17, the movement locus 5p of the light blocking member 5 is gradually increased from the tele position to the movement locus 31p of the first lens holding frame 31, and the distance L11 between each other at the intermediate position. Becomes larger than the mutual distance L13 at the tele position. Further, the mutual distance gradually decreases from the intermediate position to the wide position, and the mutual distance L12 at the wide position becomes smaller than the distance L11 at the intermediate position. Note that the second lens holding frame 32 of this embodiment moves while drawing a movement locus 32p different from the movement locus 31p of the first lens holding frame 31, as shown in FIG.

  Therefore, the light blocking member 5 blocks excess light entering the lens group 100 held by the first lens holding frame 31 at the intermediate portion of the light blocking member imaging region groove 23a. Thereby, a clear image can be obtained by removing the flare in accordance with the movement (position) of the lens group 100 held by the first lens holding frame 31.

  At that time, the first connecting portion 55a and the connecting groove 31i can surely move the light shielding member 5 smoothly in the axial direction without rotating with respect to the first lens holding frame 31, while the second connecting portion. 55b and the third connecting portion 55c and each of the connecting grooves 31i, the entire connecting portions 55a to 55c and the connecting grooves 31i are not over-constrained due to manufacturing errors or the like, so that the light shielding member 5 is attached to the first lens holding frame 31. Can move smoothly.

  Furthermore, when the cam operating ring 15 is rotated and the cam cylinder 2 rotates, the cam follower 6 for the light-shielding member, the cam follower 4 for the holding frame held by the first lens holding frame 31, and the second lens. Each of the holding frame cam followers 4 held by the holding frame 32 is located on the front side along each of the light shielding member shooting area groove 23a, the first cam groove shooting area groove 21a, and the second cam groove shooting area groove 22a. Move relative to.

  Then, during the relative movement, each of the light shielding member 5, the first lens holding frame 31, and the second lens holding frame 32 moves to the front side to be in the state shown in FIG.

  In the above embodiment, the first holding frame cam groove 21 and the second holding frame cam groove 22 have the second cam groove shooting area groove 22a and the mounting groove 24 having the same groove width. However, the present invention is not limited to this, and can be changed as appropriate.

  For example, as shown in FIG. 18, the first holding frame cam groove 121 and the incorporation groove 124 are formed wider than the second cam groove photographing region groove 22a, and the first holding frame cam groove 121 is formed. The diameter of the holding frame cam follower that engages with the second holding frame cam groove 22 may be larger than the diameter of the holding frame cam follower that engages with the second holding frame cam groove 22.

  Even in this case, the positions of the holding frame cam follower that engages with the first holding frame cam groove 121 and the holding frame cam follower that engages with the second holding frame cam groove 22 are determined by the positions of the first lens holding frame and the second lens. By bringing the holding frame into contact with each other, the positions of the first holding frame cam groove 121 and the second holding frame cam groove 22 can be adjusted. In FIG. 18, the light shielding member cam groove 23 is omitted.

  In the above embodiment, the two lens holding frames of the first lens holding frame and the second lens holding frame are engaged with the cam groove for the holding frame of the cam cylinder. It can be changed as appropriate. For example, three or more lens holding frames may be engaged with the holding frame cam groove of the cam barrel, and the present invention can be similarly applied to such a lens barrel.

DESCRIPTION OF SYMBOLS 1 Lens barrel body 2 Cam cylinder 4 Holding frame cam follower 5 Light shielding member 6 Cam follower for light shielding member 7a, 8a Main cam follower holding part 7b, 8b Sub cam follower holding part 11 Fixed cylinder 12a 1st guide shaft 12b 2nd guide shaft 21 1st holding Frame cam groove 21a First cam groove photographing area groove 21b First cam groove introducing groove 22 Second holding frame cam groove 22a Second cam groove photographing area groove 22b Second cam groove introducing groove 23 For light shielding member Cam groove 24 Assembling groove 31 First lens holding frame 32 Second lens holding frame

Claims (4)

A lens holding frame for holding a lens group having one or a plurality of lenses, a holding frame cam follower disposed on the outer periphery of the lens holding frame, and a holding frame engaged with the respective leading ends of the holding frame cam followers A rotatable cam cylinder having a cam groove, and the lens holding frame moves in the optical axis direction when the tip of the holding frame cam follower moves relative to the holding frame cam groove as the cam cylinder rotates. A lens barrel,
The lens holding frame includes a first lens holding frame and a second lens holding frame which are disposed in order on the inner peripheral side of the cam cylinder in the optical axis direction.
The holding frame cam follower includes a first holding frame cam follower disposed on the first lens holding frame, and a second holding frame cam follower disposed on the second lens holding frame,
The holding frame cam groove includes a first holding frame cam groove that receives the tip of the first holding frame cam follower and a second holding frame cam groove that receives the tip of the second holding frame cam follower. And
The first holding frame cam groove is provided with a first cam groove introducing groove on one end side thereof for introducing the tip of the first holding frame cam follower,
The second holding frame cam groove is provided with a second cam groove introducing groove on one end side thereof for introducing the tip of the second holding frame cam follower,
The cam cylinder incorporates the tip end portion of the first holding frame cam follower into the first cam groove introduction groove and incorporates the tip portion of the second holding frame cam follower into the second cam groove introduction groove. It has a groove for installation,
The incorporation groove is extended from one end surface of the cam cylinder in the axial direction so as to communicate with the first cam groove introduction groove and the second cam groove introduction groove,
The introduction groove for the first cam groove and the introduction groove for the second cam groove are in a contact state in which the pitch distance between the first and second lens holding frames contacts each other in the optical axis direction. A lens barrel configured to coincide with a pitch distance between the first holding frame cam follower and the second holding frame cam follower. The second holding frame cam groove includes a second cam groove photographing region groove that communicates with the second cam groove introducing groove and in which a distal end portion of the second holding frame cam follower relatively moves during photographing.
The introduction groove for the second cam groove includes a wide portion whose groove width is wider than the imaging region groove for the second cam groove,
2. The lens barrel according to claim 1, wherein the second cam groove introduction groove is disposed between the one end face and the cam groove introduction groove. The second holding frame cam groove includes a second cam groove photographing region groove that communicates with the second cam groove introducing groove and in which a distal end portion of the second holding frame cam follower relatively moves during photographing.
The introduction groove for the second cam groove includes a tapered portion whose groove width gradually becomes narrower toward the imaging region groove side for the second cam groove,
The lens barrel according to claim 1 or 2, wherein the second cam groove introduction groove is disposed between the one end face and the cam groove introduction groove. The first holding frame cam groove includes a first cam groove photographing region groove that communicates with the first cam groove introducing groove and in which a distal end portion of the first holding frame cam follower relatively moves during photographing.
The second holding frame cam groove includes a second cam groove photographing region groove that communicates with the second cam groove introducing groove and in which a distal end portion of the second holding frame cam follower relatively moves during photographing.
The second cam groove introduction groove is disposed between the one end surface and the first cam groove introduction groove,
2. The mounting groove, the second cam groove introducing groove, and the first cam groove photographing area groove are formed so that a groove width is wider than that of the second cam groove photographing area groove. The lens barrel according to any one of 1 to 3.