JP2009169285A - Lens barrel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lens barrel capable of shielding surely an unnecessary light ray from a clearance between fellow frame members, by simple constitution, in the contractible lens barrel. <P>SOLUTION: This lens barrel is provided with a two-group frame 11 (the first frame member) movable along an optical axis O direction, a three-group rectilinear frame 7 (the second frame member) movable along the optical axis direction relatively with respect to the two-group frame, and having an opening 50 through which one part of a light beam passing the two-group frame passes under a photographing preparatory state, a shutter frame 9 (the third frame member) movable along the optical axis direction relatively with respect to the three-group rectilinear frame, having an opening 50 communicated with an opening of the three-group rectilinear frame under the photographing preparatory state, and arranged in a position separated along the optical axis direction with respect to the three-group rectilinear frame under a contracted state, the first flexible member 51 arranged in a position closing the two openings 50 under the photographing preparatory state, and deformed by deflection due to the two-group frame to be fixed partially to the three-group rectilinear frame, under the contracted state, and the second flexible member 52 overlapped with the first flexible member to close at least part of the two openings 50 under the photographing preparatory state, and fixed to the shutter frame. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention is configured so that the lens barrel can be expanded and contracted to shorten the overall length between a use state of a form extending in a direction along the optical axis and a non-use state of a form shortened in a direction along the optical axis. The present invention relates to a lens barrel.

  Conventionally, in a lens barrel applied to a camera or the like for taking a picture, the lens barrel is extended in a direction along the optical axis and used to protrude toward the front surface of the camera casing to which the lens barrel is applied. In general, a lens barrel that can be stretched and contracted between its state and a non-use state that is shortened in the direction along the optical axis and stored in the camera housing is widely used. It is popular.

  A shortenable lens barrel having such a configuration contributes to improving the portability of a camera to which the lens barrel is applied by reducing the overall length of the lens barrel in a non-use state. There are advantages.

  On the other hand, in the lens barrel configured as described above, each of the plurality of frame members holding the plurality of optical lenses constituting the photographing optical system is moved in the direction along the optical axis. At this time, a drive motor or the like for focus driving is disposed on a predetermined frame member among the plurality of frame members, and these components also move as the frame member moves in the optical axis direction. It will be. Therefore, it is necessary to secure the movement route.

  On the other hand, in a lens barrel applied to a normal camera, unnecessary light other than the light that passes through the photographing optical system and reaches the imaging surface adversely affects the photographing result when it enters the photographing optical path. It is necessary to block such intrusion of unnecessary rays into the optical path.

  However, as described above, when a movement path of various components disposed on the frame member that moves in the optical axis direction is secured, there is a possibility that unnecessary rays may enter the imaging optical path from such a space.

  Therefore, in the conventional lens barrel, various proposals have been made on structures for blocking unnecessary light rays other than the light rays that pass through the photographing optical system and reach the imaging plane.

For example, the means disclosed in Japanese Patent Application Laid-Open No. 2004-252200 or the like prevents light from entering from a notch for allowing the motor to move in the direction along the optical axis, and prevents light leakage. In order to prevent this, a flexible light shielding sheet is provided at a predetermined portion in the lens barrel.
JP 2004-252200 A

  However, according to the means disclosed in Japanese Patent Application Laid-Open No. 2004-252200, the flexible light-shielding sheet is configured to bend every time the zoom operation is performed. There is a possibility that plastic deformation remains. In this case, there is a problem that light leakage from a portion to be shielded by the light shielding sheet is likely to occur when the light shielding sheet remains bent.

  The present invention has been made in view of the above-described points, and an object of the present invention is to reduce unnecessary light rays generated from gaps between frame members in a lens barrel, in a shortenable lens barrel. The object is to provide a lens barrel that realizes a configuration capable of reliably shielding light by the configuration.

  In order to achieve the above object, a lens barrel according to the present invention is a telescopic lens barrel, and is disposed behind the first frame member, which is movable in the optical axis direction, and behind the first frame member. A second frame member formed so as to be relatively movable in the optical axis direction with respect to the first frame member, and disposed between the first frame member and the second frame member, An imaging preparation having an opening through which unnecessary light from the front passes in the direction of the second frame member, is movable relative to the second frame member in the optical axis direction, and the lens barrel extends. In a retracted state that is spaced apart from the second frame member in the optical axis direction and shortened from the shooting preparation state, a third frame member that is closer to the second frame member than the shooting preparation state; The first frame member is abutted in the shortened state so as to close the opening in the shooting preparation state. A first flexible member disposed in front of the third frame member so as to be bent and fixed to the second frame member, and the first possible member in the direction of the optical axis in a photographing preparation state. The first flexible member is disposed immediately after the flexible member, and is fixed to the third frame member so as to overlap at least a part of the opening so as to overlap the first flexible member, and in the shortened state, the first flexible member. And a second flexible member that overlaps and contacts the bending tip of the elastic member.

  According to the present invention, in a lens barrel that can be expanded and contracted, a lens barrel that realizes a configuration capable of reliably shielding unnecessary light generated from a gap between frame members in the lens barrel with a simple configuration is provided. Can do.

  The present invention will be described below with reference to illustrated embodiments.

  1-7 is a figure which shows one Embodiment of this invention. Among these, FIG. 1 is an exploded perspective view showing the configuration of the lens barrel of the present embodiment. FIG. 2 is an exploded perspective view of a main part of the plurality of frame members constituting the lens barrel of the present embodiment, with the shutter, the third group unit, and the second group frame taken out and partially disassembled. FIG. 3 is an enlarged perspective view of the main part showing the front side of the shutter and the third group unit taken out of the plurality of frame members constituting the lens barrel of the present embodiment. FIG. 4 is an enlarged perspective view of a main part of the shutter and the third group unit shown in FIG. 5 and 6 are enlarged perspective views of main parts when the shutter and the third unit in the lens barrel of the present embodiment are taken out and viewed from the rear side. FIG. 5 is a use state, and FIG. 6 is a non-use state. Indicates the state. 7 and 8 are cross-sectional views along the plane including the optical axis of the lens barrel of the present embodiment. FIG. 7 shows a use state (wide position), and FIG. 8 shows a non-use state. FIG. 9 is an enlarged cross-sectional view of a main part showing a part of FIG. 8 in an enlarged manner. Specifically, it is an enlarged cross-sectional view when the shutter, the third group unit, and the second group frame in the lens barrel are in a non-use state.

  In the following description, the optical axis of the photographing optical system in the lens barrel of this embodiment is represented by the symbol O. In this direction along the optical axis O, the subject side is defined as the front, and the direction in which each frame member in the lens barrel is directed forward is referred to as the feeding direction. On the other hand, in the direction along the same optical axis O, the imaging side is the rear, and the direction when each frame member is moving backward is referred to as the retraction direction. The rotation direction of each component in the lens barrel is represented by the rotation direction viewed from the front side.

  The lens barrel of the present embodiment is applied to a camera, and is a telescopic photographing lens, that is, a lens barrel, which extends in a direction along the optical axis O and is applied to the lens barrel. An imaging standby state (imaging preparation state) which is a state in which the camera can perform a shooting operation by extending and projecting toward the front of the camera housing, that is, a state in which the camera is waiting for the shooting operation, and along the optical axis O The total length of the lens barrel can be extended and contracted between the shortened state in which the lens barrel is stored in the camera's casing and is not used for shooting operations. When the camera is in the shooting standby state, the zooming operation (zooming) is enabled by extending or retracting a plurality of frame members between the short focus position (wide position) and the long focus position (tele position). Zoo with a mechanism A lens barrel.

  The configuration of the lens barrel of one embodiment of the present invention will be described below with reference to FIGS.

  As shown in FIG. 1, the lens barrel 1 of the present embodiment is a fixed frame 2 fixed to a camera body (not shown), and is supported by the fixed frame 2 and serves as a drive source during zooming and collapsing operations. The rotary frame 3 that is rotated and advanced / retracted by the driving force of the drive motor 17a, and can rotate with the forward / backward movement in the direction along the optical axis O relative to the rotary frame 3 being restricted relative to the rotary frame 3 A movable frame 4, a cam frame 5 that rotates integrally with the rotary frame 3 and moves forward and backward in the direction along the optical axis O with respect to the rotary frame 3, and the optical axis O together with the cam frame 5 in a state where rotation is restricted. A rectilinear guide frame 6 that advances and retreats in the direction along, and a third group frame 10 (not shown in FIG. 1) that is driven forward and backward in the direction along the optical axis O by the rotation frame 3 in a state where rotation is restricted. (See Fig. 2, Fig. 3, etc.) The knit 32, the second group frame 11 and the first group frame 12 driven forward and backward in the direction along the optical axis O by the cam frame 5 in a state where the rotation is restricted, and the direction along the optical axis O during focusing and collapsing operations A fourth group frame 13 which is a focusing lens frame that is driven forward and backward, a first group lens 21 (not shown in FIG. 1; see FIGS. 7 and 8 to be described later), and a second group frame 11 held by the first group frame 12. A photographic optical system including a second group lens 22, a third group lens 23 held by the third group frame, and a fourth group lens 24 which is a focusing lens held by the fourth group frame 13; The holding plate 15 or the like.

  An imaging unit (not shown) is mounted on the rear side of the lens barrel 1. This imaging unit is made up of structural members including an imaging device and the like, and is fixed with screws to the rear end surface of the fixed frame 2 to which the holding plate 15 is attached. As a result, the imaging unit is fixedly held on the rear side of the lens barrel 1.

  The fixed frame 2 is formed in a cylindrical shape, and an inclined cam groove portion formed in a direction inclined with respect to the optical axis O and a circumferential groove portion formed in a direction along the circumference are connected to the inner peripheral portion thereof. Cam groove 2a, and rectilinear grooves 2b and 2c formed in the direction along the optical axis O.

  Further, on the outer peripheral portion of the fixed frame 2, a zoom motor that is a unit for performing a zooming operation of the photographing optical system and is a zoom drive source, a gear train that transmits the drive power of the zoom motor, a long gear, and the like A zooming unit 17 and a focusing unit 18 which is a unit for performing a focusing operation of the photographing optical system, and includes a focus motor as a focus driving source, a gear train for transmitting a driving force of the focus motor, a feed screw, a guide shaft, and the like. Are arranged.

  The zooming unit 17 causes the zoom optical system (the first lens group 21, the second lens group 22, and the third lens group 23) that contributes to the zooming operation of the photographic optical system of the lens barrel 1 by the zoom motor in the direction along the optical axis O. It is a zoom drive mechanism for driving, and further performs a collapsing operation for driving the lens barrel 1 from the photographing standby state to the shortened state.

  The focusing unit 18 serves as a focus driving mechanism that drives a focusing optical system (fourth group lens 24) that contributes to a focusing operation in the photographing optical system of the lens barrel 1 in a direction along the optical axis O by a focus motor. is doing.

  Although the long gear of the zooming unit 17 is not particularly illustrated, the gear rotation axis is arranged in parallel to the optical axis O and is rotatably supported in a state where it is exposed to the inner peripheral portion of the fixed frame 2. .

  The rotating frame 3 is formed in a cylindrical shape, and is fitted in the inner peripheral portion of the fixed frame 2 in a state where the rotating frame 3 can rotate and advance and retract. A cam follower 3 a that is slidably fitted into the cam groove 2 a of the fixed frame 2 and a gear portion 3 b that meshes with the long gear are formed on the outer peripheral rear portion of the rotating frame 3.

  Further, on the inner peripheral portion of the rotating frame 3, a three-group cam groove 3d formed in a direction inclined with respect to the optical axis O, and a cam frame straight-groove 3c formed in a direction along the optical axis O are provided. have. The cam frame rectilinear groove 3c is engaged with a cam follower 41 of the cam frame 5 which will be described later, so that the cam frame 5 and the rotating frame 3 rotate together, and the cam frame 5 is in the optical axis with respect to the rotating frame 3. It is possible to move in the direction along O.

  Furthermore, a plurality of bayonet protrusions 3e formed so as to protrude inward are disposed on the rear end portion of the inner periphery of the rotating frame 3 so as to sandwich the cam frame straight groove 3c. The bayonet protrusion 3e is provided to bayonet-couple the rotating frame 3 and the moving frame 4 by being fitted into a circumferential groove 4e of the moving frame 4 as will be described later. Therefore, in a state in which the rotating frame 3 and the moving frame 4 are bayonet-coupled, the moving frame 4 is rotatable at the inner peripheral portion of the rotating frame 3, and the moving frame 4 has an optical axis O with respect to the rotating frame 3. The forward / backward movement in the direction along the line is regulated.

  As described above, the cam follower 3a of the rotating frame 3 is slidably fitted into the cam groove 2a of the fixed frame 2, and the gear portion 3b is engaged with the long gear. Therefore, when the zoom motor of the zooming unit 17 is driven and the long gear is rotationally driven, the driving force is transmitted to the rotary frame 3 via the gear portion 3b, and the rotary frame 3 is rotated. . When the rotating frame 3 rotates in this manner, the cam follower 3a of the rotating frame 3 moves along the inclined cam groove portion of the cam groove 2a of the fixed frame 2, so that the rotating frame 3 is shortened while being rotated (collapsed state). From the position at the position to the short focus position in the shooting standby state. When the lens barrel 1 is in the shooting standby state, during the zooming operation from the short focal position to the long focal position, the rotating frame 3 is formed by the cam follower 3a and the circumferential groove portion of the cam groove 2a. It is driven only in the rotation direction without moving back and forth in the direction along the optical axis O.

  The moving frame 4 is formed in a cylindrical shape, and is fitted in the inner peripheral portion of the rotating frame 3 so as to be relatively rotatable. A guide projection 4 a that fits into the rectilinear groove 2 b of the fixed frame 2 projects outward from the outer periphery of the rear end of the moving frame 4. As a result, the moving frame 4 can be moved back and forth in the direction along the optical axis O while being restricted by the fixed frame 2.

  Further, the moving frame 4 includes a three-group rectilinear groove 4b formed in a direction along the optical axis O, a cam frame cam groove 4c formed in a direction inclined with respect to the optical axis O, and an outer peripheral rear portion. The bottomed circumferential groove 4e is formed. Note that each of the third group rectilinear groove 4b and the cam frame cam groove 4c is a groove portion penetrating the inner and outer peripheries.

  The moving frame 4 is disposed so as to be fitted into the inner peripheral portion of the rotating frame 3 in a state where the bayonet protrusion 3e of the rotating frame 3 is fitted into the circumferential groove 4e. Thereby, the moving frame 4 is bayonet-coupled so that it can rotate relative to the rotating frame 3 and does not move forward and backward relative to the rotating frame 3 in the direction along the optical axis O. .

  Further, a rectilinear groove that is formed in a direction along the optical axis O in the inner peripheral portion of the moving frame 4 and that restricts the rotation of the rectilinear guide frame 6 by fitting a guide protrusion 6a of the rectilinear guide frame 6 described later. 4d is formed.

  The cam frame 5 is formed in a cylindrical shape and is disposed so as to be fitted into the inner peripheral portion of the moving frame 4. The cam frame 5 has a cam follower 41 projecting outward at the outer peripheral rear part. The cam frame 5 is provided with a second group cam groove 5 a and a first group cam groove 5 b formed in a direction inclined with respect to the optical axis O.

  The cam follower 41 of the cam frame 5 is slidably engaged with the cam frame cam groove 4 c of the moving frame 4, and penetrates in the engaged state. Further, the tip of the cam follower 41 is the cam frame of the rotating frame 3. It is inserted and supported in the straight groove 3c. As a result, the cam frame 5 is supported so as to rotate integrally with the rotary frame 3 and to be movable back and forth in the direction along the optical axis O relative to the rotary frame 3.

  The rectilinear guide frame 6 is formed in a cylindrical shape, and has a guide projection 6 a that fits in the rectilinear groove 4 d of the moving frame 4 on the outer periphery of the rear end. Further, the rectilinear guide frame 6 includes a double-group rectilinear groove 6b formed so as to penetrate the inner and outer peripheries in the direction along the optical axis O, and a bottomed bottom formed on the outer peripheral surface in the direction along the optical axis O. It has a straight groove 6c for one group and a notch-like cam portion 6e that is formed on the front end side and drives a barrier drive lever (not shown).

  The rectilinear guide frame 6 is disposed in a state of being fitted into the inner peripheral portion of the first group frame 12 disposed inside the cam frame 5. At this time, the guide protrusion 6 a of the rectilinear guide frame 6 is fitted in the rectilinear groove 4 d of the moving frame 4. As a result, the linear guide frame 6 is supported by the moving frame 4 so as to advance and retreat, and the rotation is restricted. Further, a guide protrusion (not shown) of the first group frame 12 is fitted into the first group straight movement groove 6 c of the straight guide frame 6. Thereby, the linear guide frame 6 supports the group frame 12 so as to be able to advance and retreat and restricts the rotation.

  The rectilinear guide frame 6 is rotatable with respect to the cam frame 5 and moves integrally with the cam frame 5 in the direction along the optical axis O.

  The second group frame 11 is formed in a cylindrical shape and is arranged in a state of being fitted into the inner peripheral portion of the rectilinear guide frame 6. A second group lens 22 is held at a substantially central portion of the second group frame 11, a guide projection 11a projecting outward on the outer periphery, and projecting outward on the guide projection 11a. The cam follower 43 is provided.

  The guide protrusion 11a is adapted to fit into the second group straight movement groove 6b of the straight movement guide frame 6, and the cam follower 43 is inserted through the second group straight movement groove 6b and provided on the outer side thereof. The second group cam groove 5a is slidably fitted. Therefore, the second group frame 11 is driven to advance and retract by the cam frame 5 in a state in which the rotation is restricted by the rectilinear guide frame 6.

  The first group frame 12 has a frame member 20 formed in a cylindrical shape and a first group lens holding frame 12a (not shown in FIG. 1) for holding a first group lens 21 (see FIGS. 7 and 8) inside the frame member 20. 7, etc.) and is arranged in a state of being fitted on the outer peripheral side of the rectilinear guide frame 6 and on the inner peripheral side of the cam frame 5.

  A lens barrier 27 is disposed inside the front surface of the first group frame 12 so that the front surface of the first group lens 21 can be opened and closed. In addition, a plurality of guide protrusions (not shown) that are formed in the direction along the optical axis O and project inwardly on the inner peripheral portion of the first group frame 12 are equally spaced in the inner peripheral direction ( For example, three). A cam follower 44 that fits in the cam groove 5b for the first group of cam frames 5 is disposed outward at the rear end on the outer peripheral side of the first group frame 12 corresponding to the portion where the guide protrusions are disposed. Yes.

  As described above, the guide protrusions of the first group frame 12 are fitted into the first group straight grooves 6 c of the straight guide frame 6. Thus, the first group frame 12 is driven to advance and retreat in the direction along the optical axis O by the cam coupling of the cam follower 44 and the first group cam groove 5b in a state in which the rotation is restricted by the rectilinear guide frame 6.

  The lens barrier 27 is rotatably supported at the front end portion of the first group frame 12 so as to be opened and closed by a barrier drive lever (not shown) that is rotatably supported in a spring-biased state. It has become. The barrier drive lever is configured to drive the lens barrier 27 in the closing direction in conjunction with being rotationally driven by the notched cam portion 6e of the rectilinear guide frame 6 during the retracting operation of the lens barrel 1. Yes.

  As shown in FIG. 2 and the like, the shutter and third group unit 32 includes a third group rectilinear frame 7 disposed on the rear end side, a shutter frame 9 that holds a shutter mechanism, and a third group that holds a third group lens 23. The frame 10 (not shown in FIG. 1; see FIGS. 2 and 3), the plate member 8, the first light-shielding sheet 51 as the first flexible member, and the second flexible member. It is constituted by a certain second light shielding sheet 52 or the like.

  The third group rectilinear frame 7 is formed of a substantially circular plate member as shown in FIG. 2, FIG. 3, FIG. 5 and FIG. It is installed. Further, the third group rectilinear frame 7 is formed with an arm portion so as to extend in three outward directions, and a guide projection 7a is provided at each of the tips of the arm portions. A cam follower 42 protrudes further outward from each guide protrusion 7a.

  The third group rectilinear frame 7 is arranged in a state of being fitted inside the moving frame 4, the guide protrusion 7 a is fitted into the third group rectilinear groove 4 b of the moving frame 4, and the cam follower 42 passes through this to move the cam follower 42. 3 is inserted into the third group cam groove 3d. Thus, the third group rectilinear frame 7 is driven to advance and retract by the rotating frame 3 while being restricted by the moving frame 4.

  A shutter frame 9 is disposed on the front side of the third group rectilinear frame 7 so as to sandwich the third group frame 10. The third group frame 10 is arranged in a space between the third group rectilinear frame 7 and the shutter frame 9 in a state in which movement in the direction along the optical axis O is restricted with respect to the third group rectilinear frame 7. Yes.

  Specifically, the third group frame 10 is rotatable (swingable) in a direction orthogonal to the optical axis O by a support shaft 10a planted forward in the direction along the optical axis O on the third group rectilinear frame 7. It is pivotally supported with respect to the three-group rectilinear frame 7 so as to be movable. In this case, the third group frame 10 is moved from the optical axis O to the position where the third group lens 23 is disposed on the optical axis O by the support shaft 10a (the state shown in FIG. 5). It is pivotally supported so as to be rotatable with respect to the retreat position (state shown in FIG. 6).

  Therefore, the rectilinear frame 7 for the third group is retracted enough to retract the third group frame 10 out of the optical path of the photographing light beam when the third group frame 10 is rotated from the optical axis to the outside of the optical path. It is formed with a space inside.

  The shutter frame 9 is a frame member that holds a shutter mechanism that includes a shutter blade that opens and closes a central opening and a shutter actuator that rotationally drives the shutter blade. The shutter frame 9 has an approximately central opening as shown in FIG. It is comprised with the form which attached the said various structural member to the substantially circular shaped board member which has this.

  The shutter frame 9 is moved in the direction along the optical axis O with respect to the third group rectilinear frame 7 by a support shaft 47 which is planted forward in the direction along the optical axis O on the third group rectilinear frame 7. As is possible, it is pivotally supported with respect to the third group rectilinear frame 7. A coil spring 48 is wound around the support shaft 47. The coil spring 48 is disposed between the shutter frame 9 and the third group rectilinear frame 7 in a compressed state. Accordingly, the shutter frame 9 is urged in a direction that is always separated forward from the third group rectilinear frame 7 by the extensible urging force of the coil spring 48.

  As shown in FIG. 4, a second light shielding sheet 52 (second flexible member) is attached to a predetermined part on the front side of the shutter frame 9.

  In front of the shutter frame 9, the plate member 8 is fixed to the third group rectilinear frame 7 by, for example, a plurality of screws 49 (see FIG. 2) so as to sandwich the shutter frame 9 in the optical axis direction. The position is regulated in the forward direction of the optical axis. The third group rectilinear frame 7 together with the leather plate member 8 constitutes a second frame member. As shown in FIG. 3, a first light shielding sheet 51 (first flexible member) is attached to the front surface side of the leather plate member 8 in the optical axis direction.

  The first and second light shielding sheets 51 and 52 are formed by forming a flexible material such as polyethylene terephthalate (abbreviated as PET) into a sheet shape.

  By the way, when the shutter frame 9 is attached to the third group rectilinear frame 7, an optical path through which the photographing light flux passes is formed by communicating the central opening of both. When the lens barrel 1 is in the shooting standby state, the third group frame 10 is disposed on this optical path.

  In this case, in the third-group rectilinear frame 7, the three-group rectilinear frame 7 and the shutter frame 9 are indicated by reference numeral 50 in FIG. An opening (notch) is formed. For this reason, light rays that are unnecessary light other than light rays that pass through the third group lens 23 of the third group frame 10 disposed on the optical path pass through the aperture 50 from the front to the rear of the photographing lens and enter the optical path. there is a possibility.

  Therefore, in the present embodiment, the lens barrel 1 is placed in a shooting standby state by sticking the first light shielding sheet 51 and the second light shielding sheet 52 to predetermined portions of the plate plate member 8 and the shutter frame 9, respectively. Sometimes, the first light-shielding sheet 51 and the second light-shielding sheet 52 are arranged at positions where the opening 50 is closed.

  In other words, the first light-shielding sheet 51 attached to the leather plate member 8 is disposed so as to close the substantially lower half of the opening 50 as shown in FIG. Moreover, the 2nd light shielding sheet 52 stuck to the shutter frame 9 is arrange | positioned so that the substantially upper half part of the opening 50 may be plugged up, as shown in the figure. At this time, the arrangement of both the first light-shielding sheet 51 and the second light-shielding sheet 52 is set so that a part of each of them is superimposed.

  For this purpose, the first light shielding sheet 51 has a part of the opening 53 so that a part of the first light shielding sheet 51 protrudes from the inner edge of the press plate member 8 toward the shutter frame 9 and the central opening 53 of the third group rectilinear frame 7. It is arranged to close up. Further, the second light shielding sheet 52 blocks a part of the opening 53 so that a part of the second light shielding sheet 52 protrudes from the outer edge portion of the shutter frame 9 toward the central opening 53 of the shutter frame 9 and the third group rectilinear frame 7. Are arranged as follows.

  On the other hand, the first light shielding sheet 51 and the second light shielding sheet 52 are formed of a flexible material as described above. Therefore, when the lens barrel 1 shifts from the photographing standby state to the shortened state (collapsed state), the first light-shielding sheet 51 has a predetermined portion (see FIG. 7 to be described later) at the rear edge of the second group frame 11. It is deformed into a predetermined shape bent by the contact of the part indicated by the symbol A). At the same time, the second light shielding sheet 52 moves from the optical axis O to the outside of the optical axis as the lens barrel 1 shifts from the photographing preparation state to the shortened state (collapsed state). It is bent by the contact of the third group frame 10 retracted from the road and overlaps with the bent tip of the first light shielding sheet 51 so as to be deformed into a predetermined form.

  Further, the second light-shielding sheet 52 causes the first light-shielding sheet 51 to be in a state before deformation when the lens barrel 1 is shifted from the shortened state (collapsed state) to the photographing preparation state. To restore.

  The first light-shielding sheet 51 and the second light-shielding sheet 52 are each a member to which the first light-shielding sheet 51 and the second light-shielding sheet 52 are attached when they are bent by the predetermined frame members, that is, the inner peripheral edge of the leather plate member 8 A plurality of slits 51a and 52a, which are line-shaped notches, are formed so that the edges of the respective light shielding sheets 51 and 52 bend along the outer peripheral edge of the shutter frame 9. As described above, the shutter and the third group unit 32 are configured.

  The fourth group frame 13 is a frame member that holds the fourth group lens 24. A long arm portion 13e and a short arm portion 13f extending outward are provided on the outer periphery of the fourth group frame 13. A shaft hole 13a through which a guide shaft (not shown) of the focusing unit 18 is inserted is formed in the vicinity of the distal end portion of the long arm portion 13e. Further, a guide projection 13b that is slidably engaged with the rectilinear groove 2c of the fixed frame 2 is formed in the vicinity of the distal end portion of the short arm portion 13f.

  The fourth group frame 13 is inserted and arranged behind the fixed frame 2, and is movable forward and backward in the direction along the optical axis O with respect to the fixed frame 2.

  That is, when the guide shaft is rotated via the gear train and the feed screw by the driving force of the focus drive source (focus motor) of the focusing unit 18, the fourth group frame 13 is moved along the direction of the guide shaft, that is, the optical axis. Driven back and forth in a direction along O, the lens is arranged at an appropriate focusing position when in a photographing standby state and at a predetermined retracted position during a collapsing operation.

  In addition, an opening is formed in a substantially central portion of the fourth group frame 13, and the fourth group lens 24 is fixedly held in an inner portion of the opening.

  The holding plate 15 is made of a metal plate-like member, and is fixed to the rear end surface of the fixed frame 2 in the assembled lens barrel 1 with, for example, screws. The holding plate 15 is provided with an opening 15a at a substantially central portion. As described above, an imaging unit (not shown) is arranged at the site of the opening 15a.

  The operation of the lens barrel 1 having the above-described configuration according to the embodiment will be described below with reference to FIGS. 7, 8, and 9.

  First, when the lens barrel 1 of the present embodiment is in a shooting standby state, as shown in FIG. 7, each frame member moves forward in the direction along the optical axis O, and the lens barrel 1 Is in an extended state as a whole.

  As shown in FIG. 7, in this photographing standby state, the second group frame 11 and the shutter and third group unit 32 are arranged at positions separated from each other. Therefore, the first light-shielding sheet 51 and the second light-shielding sheet 52 attached to the predetermined portions of the shutter and the third group unit 32, that is, the press plate member 8 and the predetermined portions of the shutter frame 9, are superimposed on each other. It arrange | positions so that the opening 50 may be plugged up in a form.

  When the lens barrel 1 shifts from the photographing standby state to the retracted state, first, the second group frame 11 moves rearward in the direction along the optical axis O. Along with this movement, the predetermined portion A of the rear edge of the second group frame 11 comes into contact with the first light shielding sheet 51, and as shown in FIGS. 8 and 9, the optical axis side edge of the first light shielding sheet 51. A part of is bent backward and deformed.

  The second group frame 11 contacts the shutter frame 9 and moves the shutter frame 9 backward in the direction along the optical axis O against the urging force of the coil spring 48 while maintaining the contact state. At the same time, the third group frame 10 moves from the position on the optical axis O to the outside of the optical axis and retracts from the optical path.

  As a result, a predetermined portion of the outer peripheral edge of the third group frame 10 comes into contact with the second light shielding sheet 52, and a part of the lower side edge of the second light shielding sheet 52 is moved forward as shown in FIGS. Bend towards and deform. In this way, the lens barrel 1 is in the retracted state.

  When the lens barrel 1 shifts from the retracted state to the photographing standby state again, the second group frame 11 moves in the direction along the optical axis O toward the front. With this movement, the contact state between the predetermined portion A of the rear edge of the second group frame 11 and the first light shielding sheet 51 is released. Thereby, the 1st light shielding sheet 51 returns to the flat form of the original form with its own restoring force.

  At this time, the shutter frame 9 also moves in the direction along the optical axis O toward the front. As a result, the second light shielding sheet 52 comes into contact with the vicinity of the front end portion of the first light shielding sheet 51 in the deformed state, and also acts to push it forward. Thereby, the 2nd light shielding sheet 52 acts so that the 1st light shielding sheet 51 may be restored to the state before a deformation | transformation.

  At the same time, the third group frame 10 moves from the position of the optical axis town to the position on the optical axis O and is arranged on the optical path. Thereby, the contact state between the predetermined portion of the outer peripheral edge of the third group frame 10 and the second light shielding sheet 52 is released. Then, the 2nd light shielding sheet 52 returns to an original form of a flat plate shape by its own restoring force. Thus, the present lens barrel 1 is in a shooting standby state shown in FIG.

  As described above, according to the above-described embodiment, the extendable lens barrel 1 includes the second group frame 11 that is the first frame member that is movable in the direction along the optical axis O, and the second group frame 11. Further, the third group rectilinear frame 7, which is a second frame member that is disposed further rearward of the optical axis and is relatively movable in the direction along the optical axis O with respect to the second group frame 11, and the second group frames 11 and 3 A direction which is disposed between the group straight traveling frame 7 and has an opening through which unnecessary light from the front passes in the direction of the third group straight traveling frame 7, and is along the optical axis O with respect to the third group straight traveling frame 7. In the retracted state, the lens barrel 1 is separated from the third-group rectilinear frame 7 in the direction along the optical axis O in the shooting preparation state in which the lens barrel 1 is extended. The shutter frame 9 is a third frame member that is closer to the frame 7 than the shooting preparation state, and is shortened so as to close the opening in the shooting preparation state. In the state, a first light-shielding sheet 51 that is a first flexible member that is disposed in front of the shutter frame 9 and fixed to the third-group rectilinear frame 7 so as to be bent by the contact of the second-group frame 11; In the shooting preparation state, it is disposed immediately after the first light shielding sheet 51 in the optical axis direction, and is fixed to the shutter frame 9 so as to overlap with the first light shielding sheet 51 and close at least a part of the opening. A second light-shielding sheet 52 that is a second flexible member that overlaps and contacts the bending tip of the light-shielding sheet 51 is configured.

  The opening is an opening for avoiding interference with a member outside the optical axis in the lens barrel 1.

  The lens barrel 1 further includes a third group frame 10 that is a fourth frame member provided on the third group rectilinear frame 7 so as to be swingable between the optical axis and the outside of the optical axis. As the lens barrel 1 shifts from the photographing preparation state to the retracted state, the third group frame 10 shifts from the optical axis O to the outside of the optical axis to bend the second light shielding sheet 52. Yes.

  The second light shielding sheet 52 acts so as to restore the first light shielding sheet 51 to the state before the deformation as the lens barrel 1 shifts from the retracted state to the photographing preparation state. It is composed.

  That is, the lens barrel 1 of the present embodiment is a lens barrel 1 that is configured to be displaceable and shortened between a use state (shooting standby state) and a non-use state (shortening state; retracted state). A pair of light shielding sheets (a first light shielding sheet 51 and a second light shielding sheet 52) for shielding unnecessary light incident from an opening generated structurally between the frame members moving in the direction along the optical axis O is provided. When the lens barrel 1 is in a shooting standby state, the pair of light shielding sheets are arranged so as to close the opening in a form that partially overlaps, and when the lens barrel 1 is in the retracted state, the pair of light shielding sheets Are housed in a deformed form by being bent by a first frame member (second group frame 11) moving in a direction along the optical axis O and a third group frame 10 retracting in a direction orthogonal to the optical axis. I am doing so.

  As a result, when the lens barrel 1 is in the shooting standby state, the opening can be closed by the pair of light shielding sheets of the first light shielding sheet 51 and the second light shielding sheet 52, thereby reliably blocking the incidence of unwanted light rays. Can do.

  Further, when the lens barrel 1 is in a shortened state (collapsed state), the first light shielding sheet 51 and the second light shielding sheet 52 can be housed in a deformed form, so that useless occupied space is not required. The lens barrel 1 can be shortened.

  Moreover, although the opening 50 is provided in order to avoid interference with the third group frame 10, even if it is not a frame member called the third group frame 10, it is for avoiding interference with members in the lens barrel. It may be a thing. For example, the member may be an actuator such as a motor provided with the member fixed in the lens barrel.

  Note that the present invention is not limited to the above-described embodiment, and various modifications and applications can of course be implemented without departing from the spirit of the invention. Further, the above embodiments include inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements. For example, even if some constituent elements are deleted from all the constituent elements shown in the embodiment, the problem described in the column of the problem to be solved by the invention can be solved, and the effect described in the effect of the invention Can be obtained as an invention.

1 is an exploded perspective view illustrating a configuration of a lens barrel according to an embodiment of the present invention. The principal part disassembled perspective view which takes out a shutter, the 3 group unit, and the 2nd group frame out of the some frame members which comprise the lens barrel of this embodiment, and disassembles and shows one part. The principal part expansion perspective view which takes out a shutter and a 3 group unit from the some frame members which comprise the lens barrel of this embodiment, and shows the front side. FIG. 4 is an enlarged perspective view of a main part of the shutter and the third group unit shown in FIG. The principal part expansion perspective view at the time of taking out the shutter and 3 group unit in the use condition of the lens-barrel of this embodiment, and seeing from the rear surface side. The principal part expansion perspective view at the time of taking out the shutter and 3 group unit in the non-use state of the lens barrel of this embodiment, and seeing from the rear surface side. Sectional drawing which follows the surface containing the optical axis in the use condition of the lens-barrel of this embodiment. Sectional drawing which follows the surface containing the optical axis in the non-use state of the lens barrel of this embodiment. The principal part expanded sectional view which expands and shows a part of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Lens barrel 2 ... Fixed frame 3 ... Rotating frame 4 ... Moving frame 5 ... Cam frame 6 ... Straight guide frame 7 ... 3 group rectilinear frame 8 ... Press plate member 9 ... Shutter Frame 10 ... Third group frame 11 ... Second group frame 12 ... First group frame 13 ... Fourth group frame 15 ... Holding plate 27 ... Lens barrier 32 ... Shutter and third group unit 47 ... Support shaft 48 ... Coil spring 49 ... screw 50 ... opening 51 ... first light shielding sheet 52 ... second light shielding sheets 51a, 52a ... slit

Claims (4)

In a telescopic lens barrel,
A first frame member movable in the optical axis direction;
A second frame member disposed behind the first frame member in the optical axis direction and movable relative to the first frame member in the optical axis direction;
The second frame member is disposed between the first frame member and the second frame member, and has an opening through which unnecessary light from the front passes in the direction of the second frame member. In the retracted state, which is relatively movable in the optical axis direction, is spaced apart from the second frame member in the optical axis direction in the shooting preparation state in which the lens barrel is extended, and is shorter than the shooting preparation state, A third frame member that is closer to the second frame member than the above-mentioned shooting preparation state;
It is arranged in front of the third frame member and fixed to the second frame member so as to be bent by the contact of the first frame member in the shortened state so as to close the opening in the photographing preparation state. A first flexible member,
In the photographing preparation state, the third frame member is disposed immediately after the first flexible member in the optical axis direction, and overlaps with the first flexible member to block at least a part of the opening. A second flexible member that is fixedly attached to the first flexible member and is in contact with the first flexible member in a shortened state;
An expandable / contractible lens barrel.   2. The shortenable lens barrel according to claim 1, wherein the opening is an opening for avoiding interference with a member outside the optical axis in the barrel.   The lens barrel further includes a fourth frame member provided on the second frame member so as to be able to swing between the optical axis and the outside of the optical axis, from the photographing preparation state to the retracted state. The fourth frame member moves from on the optical axis to the outside of the optical axis as a result of the transition, and the second flexible member is bent by coming into contact with the second flexible member. The shortenable lens barrel according to claim 1.   The second flexible member restores the first flexible member to a state before the deformation of the first flexible member as the lens barrel shifts to a photographing preparation state. A telescopic lens barrel characterized by.

Images