JP2014048450A - Lens barrel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lens barrel which is capable of highly accurately moving lens holding frames, is resistant to shock, and is less likely to have cam followers engaged in cam grooves too tightly.SOLUTION: A lens barrel includes: first and second lens holding frames 31, 32; holding frame cam followers 4 attached on outer peripheries of the first and second lens holding frames 31, 32; and a cam barrel 2 having a plurality of holding frame cam grooves 21, 22 engaged with tip portions of the holding frame cam followers 4. Each of the first and second lens holding frames 31, 32 has one main cam follower retaining section 7a, 8a, and two sub cam follower retaining sections 7b, 8b. The main cam follower retaining sections 7a, 8a accommodate base portions of the holding frame cam followers 4 and coil springs 71b, 81, and the sub cam follower retaining sections 7b, 8b accommodate only the base portions of the holding frame cam followers 4.

Description

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

  Conventionally, lens barrels used for still cameras, video cameras, and the like are widely known. For example, in Patent Document 1, a lens holding frame that is supported on a guide shaft so as to be movable in the axial direction and holds a lens group, a single cam follower held on the outer periphery of the lens holding frame, and a compression that biases the lens holding frame A coil spring, and by urging the lens holding frame in one axial direction of the guide shaft by the compression coil spring, the tip of the cam follower is pressed against the inner surface of the cam groove of the cam cylinder, and there is a backlash between the two. There has been disclosed a lens barrel in which a lens holding frame can be moved with high accuracy without causing it.

  However, since the lens barrel disclosed in Patent Document 1 has a single cam follower, for example, when an impact force is applied to the lens holding frame from the outside, the guide shaft is bent and the tip of the cam follower is engaged. It may come off from the cam groove of the cam cylinder.

  On the other hand, for example, Patent Document 2 relates to three cam followers having the same configuration provided along the circumferential direction on the outer periphery of a lens holding frame supported so as to be axially movable on a guide shaft, and each of the three cam followers. And a cam barrel having three cam grooves of the same configuration, for example, even when an impact force is applied to the lens holding frame, a lens barrel is disclosed in which the tip of the cam follower is not easily detached from the cam groove of the cam barrel. ing.

Japanese Patent Laid-Open No. 05-241059 JP 2012-73307 A

  However, like the lens barrel disclosed in Patent Document 2, when each of the three cam followers having the same configuration is engaged with each of the three cam grooves having the same configuration, the cam follower and the cam groove are caused by a manufacturing error or the like. May become over-restrained. If the cam follower and the cam groove are over-restrained in this way, all the cam followers will not easily enter the cam groove and become difficult to engage, and even if the cam followers can be engaged, the cam grooves in which the respective distal end portions of the cam follower are engaged. There is a problem that it becomes difficult to move relative smoothly.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a lens barrel that can move a lens holding frame with high accuracy, is strong against impact force, and is less likely to be over-constrained between a cam follower and a cam groove.

  In order to solve the above problems, a lens barrel of the present invention includes a lens holding frame that is movably supported by a guide shaft and holds a lens group, a holding frame cam follower that is held on the outer periphery of the lens holding frame, and the holding A rotatable lens barrel engaged with a frame cam follower, wherein the lens holding frame moves in the optical axis direction along the guide shaft as the cam barrel rotates, the cam barrel Includes a plurality of holding frame cam grooves that are movably engaged with the tip of the holding frame cam follower, and the lens holding frame has one main cam follower holding portion and one or more sub cam follower holdings. The main cam follower holding portion includes a cam frame for the holding frame, wherein the cam follower for the holding frame is moved in the cam groove for the holding frame by the urging member. The holding frame cam follower is held such that the holding frame cam follower can be moved relative to the inner side surface of the groove at all times, and the sub cam follower holding portion is a holding frame cam other than any one of the holding frame cam followers. The holding frame cam follower is held in such a manner that the holding frame cam follower can be moved relative to the inner surface of the other holding frame cam groove in a non-contact state. The sub cam follower holding portion has an angular phase different from that of the main cam follower holding portion. It has the 1st sub cam follower holding | maintenance part arrange | positioned in the position, It is characterized by the above-mentioned.

  According to this configuration, the main cam follower holding portion holds the holding frame cam follower so that the tip end portion of the holding frame cam follower can be relatively moved in a constantly contacted state. The lens holding frame can be moved along the guide axis in the optical axis direction with high accuracy without any play between the cam frame groove and the holding frame cam groove.

  Further, for example, when an impact force is applied to the lens holding frame from the outside and the guide shaft tries to bend, the tip of the holding frame cam follower held by the sub cam follower holding portion comes into contact with the inner surface of the holding frame cam groove and the lens The force applied to the holding frame can be received, and the guide shaft can be prevented from being bent. Thereby, even when an impact force is applied to the lens holding frame, it is possible to prevent the tip end portion of the holding frame cam follower from being detached from the holding frame cam groove, and to be strong against the impact force.

  On the other hand, the holding frame cam follower held by the sub cam follower holding portion is disposed in the holding frame cam groove so as to be relatively movable in a non-contact state with its tip and the inner surface of the holding frame cam groove. Further, it is possible to prevent the holding frame cam follower held by the sub cam follower holding portion from being over-constrained. As a result, the holding frame cam followers held by the main cam follower holding portion and the sub cam follower holding portion can be easily incorporated into the holding frame cam groove, and can be smoothly moved relative to each other.

  In another aspect, in the lens barrel, each of the main cam follower holding portion and the sub cam follower holding portion includes a main supported portion and a sub supported portion supported by the guide shaft, respectively. The support portion is configured such that the axial length is longer than that of the sub supported portion, and the main cam follower holding portion has a circumferential distance between the main supported portion and the sub supported portion. It arrange | positions in the position shorter than the distance of the circumferential direction, It is characterized by the above-mentioned.

  According to this configuration, since the main cam follower holding portion is arranged so that the distance in the circumferential direction from the main supported portion is shorter than that distance from the sub supported portion, the main cam follower holding portion is held by the main cam follower holding portion. The holding frame cam follower can suppress a positional shift due to a manufacturing error or the like with respect to the main supported portion, and the lens holding frame can be moved in the optical axis direction along the guide shaft with higher accuracy.

  In another aspect, in any one of the lens barrels described above, the sub cam follower holding portion is a second sub cam follower holding portion arranged so as to be aligned in the axial direction of the main cam follower holding portion and the lens holding frame. It has the part.

  According to this configuration, for example, when an impact force is applied to the lens holding frame from the outside and the guide shaft tries to bend, the tip of the second sub holding frame cam follower is pressed against the inner surface of the sub holding frame cam groove. Thus, the force applied to the lens holding frame can be shared and received in the axial direction, and the bending of the guide shaft can be further reliably suppressed. As a result, even when an impact force is applied to the lens holding frame, it is possible to more reliably prevent the cam follower from being detached from the cam groove.

  In another aspect, in any one of the lens barrels described above, the holding frame cam groove is formed such that the groove width gradually narrows radially outward, and the tip of the holding frame cam follower is The main cam follower holding portion is formed so as to gradually decrease in diameter as it goes to the tip, and the main cam follower holding portion stores the holding frame cam follower movably in the radial direction and the holding frame stored in the cam follower storage portion. And a biasing member that biases the cam follower radially outward.

  According to this configuration, the front end portion of the holding frame cam follower held by the main cam follower holding portion can be easily pressed against the inner side surface of the holding frame cam groove, thereby facilitating manufacture.

  In another aspect, in any one of the lens barrels described above, the lens holding frame includes a first lens holding frame and a second lens holding frame arranged along the optical axis direction, and the guide shaft Includes a first guide shaft and a second guide shaft, and the first guide shaft supports a main supported portion of the first lens holding frame and a sub supported portion of the second lens holding frame. The second guide shaft supports a sub supported portion of the first lens holding frame and supports a main supported portion of the second lens holding frame.

  According to this configuration, the first guide shaft functions as a main guide shaft that supports the main supported portion of the first lens holding frame, and as a sub guide shaft that supports the sub supported portion of the second lens holding frame. Can function. The second guide shaft functions as a sub guide shaft that supports the sub supported portion of the first lens holding frame, and also functions as a main guide shaft that supports the main supported portion of the second lens holding frame. it can.

  Therefore, the first guide shaft and the second guide shaft can be shared by the first lens holding frame and the second lens holding frame, respectively, and the structure can be simplified and can be manufactured at low cost.

  The lens barrel of the present invention can move the lens holding frame with high accuracy, is strong against impact force, and is less likely to be over-constrained between the cam follower and the cam groove.

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 an enlarged view of the principal part of other embodiment of the cam groove for holding frames. It is the expanded perspective view of other embodiment of the 1st lens holding frame.

  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 portion is composed of one main cam follower holding portion 7a and two sub cam follower holdings disposed at a different angular phase position from the main cam follower holding portion 7a, that is, at a position spaced apart from the main cam follower holding portion 7a in the circumferential direction. Part (first sub cam follower holding part) 7b. In this embodiment, the cam follower holding part is
One main cam follower holding portion 7 a and two sub cam follower holding portions 7 b are 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.

  The cam follower holding portion of the second lens holding frame 32 includes one main cam follower holding portion 8a (appearing on the upper side in FIG. 4) and an angular phase position different from the main cam follower holding portion 8a, that is, the main cam follower holding portion 8a. And two sub cam follower holding portions (first sub cam follower holding portions) 8b disposed at positions spaced apart from each other in the circumferential direction. In this embodiment, as shown in FIGS. 4 and 8, one main cam follower holding portion 8 a and two sub cam follower holding portions 8 b are arranged at substantially equal intervals along the circumferential direction of the second lens holding frame 32. Has been.

  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-described embodiment, the holding frame cam groove into which the holding frame cam follower held by the main cam follower holding portion enters, and the holding frame cam groove into which the holding frame cam follower held at the sub cam follower holding portion enter, Although it is configured from the same groove width, it is not limited to this form and can be changed as appropriate. For example, as shown in FIG. 18, the holding frame cam groove 121, 121a in which the holding frame cam follower 4 held in the sub cam follower holding portion enters, the holding frame cam follower in which the holding frame cam follower held in the main cam follower holding portion enters. The groove width may be wider than the grooves 22 and 22a, or the groove width may be increased and the groove depth may be formed deeper (in FIG. 18, the groove width is increased and the groove depth is increased). doing).

  In the above-described embodiment, the holding frame cam follower held by the main cam follower holding portion is urged radially outward by the coil spring. For example, the holding frame cam follower held by the main cam follower holding portion is urged to one side in the axial direction by a coil spring, and the cam groove engaging portion of the holding frame cam follower is moved to the one side in the axial direction of the holding frame cam groove. You may make it press on an inner surface.

  In the above-described embodiment, the sub cam follower holding portion includes only the first sub cam follower holding portion disposed at an angular phase position different from that of the main cam follower holding portion. However, it can be changed as appropriate. For example, as shown in FIG. 19, in addition to the first sub cam follower holding portion, one or a plurality of angular phase positions that are the same as the main cam follower holding portion, that is, arranged in the axial direction of the lens holding frame 31 A second sub cam follower holding portion 172 may be provided (in FIG. 19, an example in which one second sub cam follower holding portion 172 is disposed is illustrated).

DESCRIPTION OF SYMBOLS 1 Lens barrel body 2 Cam cylinder 4 Cam follower for holding frame 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 First guide shaft 12b Second guide shaft 21 First Holding groove 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 Light shielding member Cam groove 24 Assembling groove 31 First lens holding frame 32 Second lens holding frame

Claims (5)

A lens holding frame that is movably supported by a guide shaft and holds a lens group, a holding frame cam follower held on the outer periphery of the lens holding frame, and a rotatable cam cylinder engaged with the holding frame cam follower. A lens barrel in which the lens holding frame moves in the optical axis direction along the guide shaft as the cam barrel rotates,
The cam cylinder includes a plurality of holding frame cam grooves engaged with a distal end portion of the holding frame cam follower so as to be relatively movable,
The lens holding frame includes one main cam follower holding portion and one or more sub cam follower holding portions,
In the main cam follower holding portion, the tip end portion of the holding frame cam follower is moved by the urging member in any one of the plurality of holding frame cam grooves and the inner side surface of the one holding frame cam groove. Hold the holding frame cam follower so that it can move relative to the normal contact state,
The sub cam follower holding portion is configured such that the tip end portion of the holding frame cam follower is in a non-contact state with the inner side surface of the other holding frame cam groove in any other holding frame cam groove other than the one. Hold the holding frame cam follower so that it can move,
The sub-cam follower holding portion includes a first sub-cam follower holding portion disposed at an angular phase position different from that of the main cam follower holding portion. The main cam follower holding portion and the sub cam follower holding portion each include a main supported portion and a sub supported portion supported by the guide shaft,
The main supported portion is configured such that the axial length is longer than the sub supported portion,
The said main cam follower holding | maintenance part is arrange | positioned in the position where the distance of the circumferential direction with the said main supported part becomes shorter than the circumferential distance with the said sub supported part. Lens barrel.   The said sub cam follower holding part is provided with the 2nd sub cam follower holding part arrange | positioned so that it might arrange in the axial direction of the said main cam follower holding part and the said lens holding frame. The lens barrel described. The holding frame cam groove is formed such that the groove width gradually narrows radially outward,
The tip of the holding frame cam follower is formed so as to gradually become smaller in diameter toward the tip,
The main cam follower holding portion holds the holding frame cam follower movably in a radial direction,
The lens barrel according to any one of claims 1 to 3, wherein the urging member urges a holding frame cam follower held in the cam follower storage portion radially outward. The lens holding frame includes a first lens holding frame and a second lens holding frame arranged along the optical axis direction,
The guide shaft includes a first guide shaft and a second guide shaft,
The first guide shaft supports a main supported portion of the first lens holding frame and supports a sub supported portion of the second lens holding frame,
5. The second guide shaft according to claim 2, wherein the second guide shaft supports a sub supported portion of the first lens holding frame and supports a main supported portion of the second lens holding frame. The lens barrel according to any one of the above.