JP2014106277A - Lens barrel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lens barrel in a compact structure capable of having a converter lens inserted to or removed from an optical path.SOLUTION: A lens barrel includes a first mechanism for moving a converter lens between an insertion position and an intermediate position which is positioned in between the insertion position and an evasion position and not interfering with a photographic optical path of a zoom lens system and a second mechanism for moving the converter lens between the intermediate position and the evasion position. The converter lens is positioned in the evasion position by the second driving mechanism in a stored state of the lens barrel when not photographing and the converter lens is positioned in the intermediate position by the first driving mechanism in at least one portion of a focal distance range of the zoom lens system.

Description

  The present invention relates to a lens barrel, and more particularly to a lens barrel including a converter lens that can be inserted into and removed from an optical path.

  Lens barrels that switch focal lengths by inserting and removing a converter lens on the optical path are known (Patent Documents 1 and 2). A lens barrel that realizes a focal length outside the focal length range of the zoom lens system by inserting a converter lens on the optical path of the zoom lens system is also known (Patent Document 3).

JP-A-1-126613 JP 61-34562 A JP-A-8-234089

  In recent years, there has been a strong demand for downsizing of lens barrels, and further downsizing of lens barrels with built-in converter lenses is expected. In order to realize this, it is required to make the drive mechanism of the converter lens as compact as possible. In particular, in a retractable lens barrel, it is difficult to secure a space for storing the converter lens between the lens groups when the interval between the plurality of lens groups is reduced to reduce the thickness in the retracted (collapsed) state. Therefore, in order to avoid interference with other lens groups, it is necessary to increase the retraction movement amount of the converter lens to the outside of the optical path. There has been a demand for a compact driving mechanism for such a converter lens having a large retraction movement amount.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a lens barrel in which a converter lens can be inserted into and removed from the optical path with a compact structure.

  The present invention includes a zoom lens system including a plurality of lens groups moving in the optical axis direction and having a variable focal length, and a focal length outside the focal length range of the zoom lens system by being inserted on the optical axis of the zoom lens system. Lens with a converter lens that enables photographing with a zoom lens system and a converter lens drive mechanism that moves the converter lens between an insertion position on the optical axis of the zoom lens system and a retracted position that is detached from the optical axis It is about. The converter lens driving mechanism includes a first driving mechanism and a second driving mechanism. The first drive mechanism moves the converter lens between the insertion position and an intermediate position that is located between the insertion position and the retracted position and does not interfere with the photographing optical path of the zoom lens system. The second drive mechanism moves the converter lens between the intermediate position and the retracted position. When the lens barrel is not taken, the converter lens is positioned at the retracted position by the second drive mechanism, and at least part of the focal length range of the zoom lens system, the converter lens is moved by the first drive mechanism. Located in the middle position.

  More specifically, the lens barrel includes an insertion / removal frame that holds the converter lens, a support member that rotatably supports the insertion / removal frame about a rotation axis parallel to the optical axis of the zoom lens system, A relative movement member that performs relative movement with respect to the support member when the lens group is moved in the optical axis direction is provided. Based on this configuration, the first drive mechanism is supported by the support member and moves the insertion / removal frame between the insertion position and the intermediate position of the converter lens by rotation about an axis parallel to the rotation axis of the insertion / removal frame. A rotation drive member and a drive control unit that is formed on the relative movement member and changes the position in the rotation direction of the rotation drive member by contacting and releasing the rotation drive member by relative movement of the relative movement member with respect to the support member Have A biasing member that holds the rotation drive member at an initial position corresponding to the intermediate position of the converter lens is provided, and the drive control unit comes into contact with the rotation drive member by relative movement of the support member and the relative movement member, and the rotation drive member is inserted. It is pressed and rotated from the initial position against the urging force of the urging member.

  The relative movement member provided with the drive control unit constituting the first drive mechanism is supported so as to be linearly movable in the optical axis direction, and the plurality of lens groups are moved in the optical axis direction with respect to the support member in the optical axis direction. A type that relatively moves can be used. In this case, the linear motion guide ring that guides the support member so as to be movable in the optical axis direction is used as a relative movement member, and the drive control unit may be configured by a circumferential cam formed on the circumferential surface of the linear travel guide ring.

  A protrusion provided on the insertion / removal frame and a protrusion provided on the rotation drive member are inserted between the pair of spring arm portions, and a torsion spring that can rotate around the rotation axis of the insertion / removal frame is provided. It is preferable to hold the insertion / removal frame at an intermediate position of the converter lens and transmit the rotational force of the rotation drive member to the insertion / removal frame via the pair of spring arms.

  The lens barrel further includes a second relative movement member that moves relative to the support member when the plurality of lens groups are moved in the optical axis direction, and is inserted by relative movement of the second relative movement member relative to the support member. The second drive mechanism may be configured by a second drive control unit that makes contact with and release from the unframe and presses the insertion / removal frame to move the converter lens to the retracted position.

  As the second relative movement member, a type that is supported so as to be linearly movable in the optical axis direction and that moves relative to the support member in the optical axis direction when moving a plurality of lens groups in the optical axis direction can be used. . In this case, the second relative movement member is formed as a cylindrical member having a lens holding cylinder portion that holds at least one of the plurality of lens groups, and then protrudes in the outer diameter direction from the lens holding cylinder portion. The second drive control unit may be configured by the unit. Further, the support member holds a lens group different from the lens group held by the second relative movement member, and the lens group held by the second relative movement member is a subject more than the lens group held by the support member. It is preferable that a converter lens is inserted between these lens groups.

  In the lens barrel according to the present invention, the converter lens includes a first drive mechanism that moves the converter lens between the insertion position and the intermediate position, and a second drive mechanism that moves the converter lens between the intermediate position and the retracted position. The drive mechanism is configured. By sharing the operating range of the converter lens by the first drive mechanism and the second drive mechanism, each drive mechanism can be configured compactly and the degree of design freedom can be increased. Also, by using the intermediate position where the retracted amount of the converter lens is small and the retracted position where the retracted amount of the converter lens is large according to the extended state of the lens barrel, the storage efficiency and drive efficiency of the converter lens in the lens barrel are improved. Can be optimized.

It is a sectional side view of the storage (collapse) state of the zoom lens barrel to which the present invention is applied. FIG. 3 is a side sectional view showing a state where the zoom lens barrel is extended and located at a wide end and a tele end in a zoom range. It is a sectional side view which shows the state by which the wide converter lens was inserted on the imaging | photography optical axis with the zoom lens barrel. It is a sectional side view which shows the state by which the wide converter lens was inserted on the imaging | photography optical axis with the zoom lens barrel. It is a sectional side view which shows the state which has a wide converter lens in an intermediate position with the same zoom lens barrel. FIG. 3 is a front exploded perspective view showing a part of a shutter unit, a converter lens unit, a rectilinear guide ring, and an inner feeding cylinder constituting the zoom lens barrel. It is a front exploded perspective view showing a part of a shutter unit, a converter lens unit, a rectilinear guide ring, and an inner feeding cylinder in a state where an insertion / removal frame for holding a wide converter lens is in a retracted position. It is a front exploded perspective view showing a part of a shutter unit, a converter lens unit, a rectilinear guide ring, and an inner feeding cylinder in a state where an insertion / removal frame for holding a wide converter lens is at an intermediate position. FIG. 6 is a front exploded perspective view showing a part of a shutter unit, a converter lens unit, a rectilinear guide ring, and an inner feeding cylinder in a state where an insertion / removal frame for holding a wide converter lens is in an insertion position. It is a front view of the converter lens unit in a state where the insertion / removal frame for holding the wide converter lens is in the retracted position. It is a front view of the converter lens unit in a state where the insertion / removal frame for holding the wide converter lens is at an intermediate position. It is a front view of the converter lens unit in a state where the insertion / removal frame for holding the wide converter lens is in the insertion position.

  A collapsible zoom lens barrel 10 whose side sections are shown in FIGS. 1 to 5 includes a first lens group LG1, a shutter S, a second lens group LG2, a third lens group LG3, an optical filter 11, and an image pickup in order from the subject side. It has an imaging optical system in which the element 12 is arranged. This imaging optical system is a zoom lens system having a variable focal length, and performs zooming by moving the first lens group LG1 and the second lens group LG2 along a photographing optical axis O of the imaging optical system along a predetermined locus. The upper half section of FIG. 2 shows the wide end of the zoom range, and the lower half section of FIG. 2 shows the tele end of the zoom range. As shown in FIGS. 3 and 4, at a predetermined extension position of the zoom lens barrel 10, a wide converter lens WC is inserted between the first lens group LG1 and the second lens group LG2 (in front of the shutter S). Thus, it is possible to shoot at a focal length shorter than the wide end of the zoom lens system. In the photographing state of the zoom lens barrel 10 shown in FIGS. 2 to 5, focusing is performed by moving the third lens group LG3 along the photographing optical axis O. FIG. 1 shows a retracted (collapsed) state of the zoom lens barrel 10, and no photographing is performed in this state. In the following description, the optical axis direction means a direction parallel to the imaging optical axis O of the imaging optical system, the front means the front in the optical axis direction (subject side), and the rear means the rear in the optical axis direction (image). Surface side).

  The zoom lens barrel 10 includes a cylindrical housing 13 as a fixing member. An image sensor holder 14 is fixed to the rear part of the housing 13, and the optical filter 11 and the image sensor 12 are supported on the front surface of the image sensor holder 14.

  The third lens group LG3 is held by the third group frame 15. The third group frame 15 is supported so as to be linearly movable in the optical axis direction by a guide shaft (not shown) fixed in the housing 13 and extending in the optical axis direction, and is advanced and retracted in the optical axis direction by an AF motor (not shown). Driven.

  In addition to the support driving means for the third group lens frame 15, a zooming group block that is driven and controlled by a zoom motor (not shown) is supported inside the housing 13. The variable power group block includes an outer feeding cylinder 16, a second group lens block 17, an inner feeding cylinder (second relative movement member) 18, and a rectilinear guide ring (relative movement member) 19.

  The outer feeding cylinder 16 and the inner feeding cylinder 18 constitute an outer appearance cylinder of the zoom lens barrel 10. The outer feeding cylinder 16 has a guide protrusion 16 a that is slidably fitted into a guide groove 13 a formed on the inner peripheral surface of the housing 13. The outer feed cylinder 16 rotates by receiving a driving force of a zoom gear (not shown) rotated by a zoom motor by a peripheral gear 16b. When the outer motor cylinder 16 is rotated by driving the zoom motor, the guide protrusion 16a is guided in the guide groove 13a, and the outer cylinder 16 moves in the optical axis direction while rotating. Specifically, when the shooting state shown in FIGS. 2 to 5 is changed from the housed state of FIG. 1, the outer feeding cylinder 16 moves forward in the optical axis direction while rotating.

  The rectilinear guide ring 19 is guided through a rectilinear guide groove (not shown) formed on the inner surface of the housing 13 so as to be linearly movable in the optical axis direction. The rectilinear guide ring 19 is also configured such that the rotation guide projection 19a is slidably engaged with a circumferential groove 16c formed around the photographing optical axis O on the inner peripheral surface of the outer feed cylinder 16, so that the outer feed cylinder 19 is slidably engaged. It moves together with the second tube 16 in the optical axis direction while allowing the rotation of the 16.

  The second group lens block 17 has a configuration in which a shutter unit (support member) 21 and a converter lens unit 22 are attached to a front portion of a second group support ring (support member) 20 that supports the second lens group LG2. A rectilinear guide key 20a protruding in the outer diameter direction from the support ring 20 is slidable with respect to a rectilinear guide slot 19b (FIGS. 6 to 9) which is a long hole in the optical axis direction formed in the rectilinear guide ring 19. By being engaged, it is guided straight in the direction of the optical axis. The shutter unit 21 is provided with a shutter S that can be opened and closed, and a shutter actuator 21 a that opens and closes the shutter S. Details of the converter lens unit 22 supported on the front portion of the shutter unit 21 will be described later.

  The second group cam follower CF2 provided in the second group support ring 20 is slidably engaged with the second group control cam groove CG2 formed on the inner peripheral surface of the outer feed cylinder 16. The second group cam follower CF2 is provided at the outer diameter portion of the rectilinear guide key 20a, and protrudes to the engagement position with the second group cam follower CF2 through the rectilinear guide slot 19b penetrating the rectilinear guide ring 19 in the radial direction. The second group lens block 17 including the second group support ring 20 is linearly guided in the optical axis direction via the straight guide ring 19, so that when the outer feeding cylinder 16 rotates, the second group control block 20 according to the shape of the second group control cam groove CG2 The group lens block 17 moves along a predetermined locus in the optical axis direction.

  A cylindrical lens holding cylinder 18a surrounding the photographing optical axis O is provided inside the inner feeding cylinder 18, and the first lens group LG1 is held in the lens holding cylinder 18a. The inner feeding cylinder 18 is guided in a straight direction in the optical axis direction through a straight guide slot 19 b of the straight guide ring 19. A first group cam follower CF1 provided in the vicinity of the rear end of the inner feeding cylinder 18 is slidably engaged with the first group control cam groove CG1 formed on the inner peripheral surface of the outer feeding cylinder 16. Since the inner feeding cylinder 18 is linearly guided in the optical axis direction via the rectilinear guide ring 19, when the outer feeding cylinder 16 rotates, the inner feeding cylinder 18 is predetermined in the optical axis direction according to the shape of the first group control cam groove CG1. Move along the trajectory.

  Next, the converter lens unit 22 will be described. As shown in FIGS. 6 to 12, the converter lens unit 22 includes a support frame (support member) 30, an insertion / removal frame 31, a drive ring (first drive mechanism, rotation drive member) 32, and a drive ring holding frame 33. Have. The support frame 30 is fixedly supported on the front side of the shutter unit 21, and a wall portion that protrudes forward in the optical axis direction and faces in the circumferential direction centering on the photographing optical axis O is formed on the peripheral edge of the front surface of the support frame 30. As shown, a circumferential wall 30a and a pair of engaging projections 30b are formed. Each engagement convex part 30b has a through hole in the radial direction. Two rotation guide protrusions 30c and stoppers 30d (FIGS. 10 to 12) are formed on the front surface of the support frame 30 on the inner diameter side closer to the photographing optical axis O than the circumferential wall 30a with different circumferential positions. Has been. Each rotation guide protrusion 30c has a shape that is long in the circumferential direction about the photographing optical axis O. As shown in FIGS. 10 to 12, the stopper 30 d is formed as a convex portion protruding in the inner diameter direction of the support frame 30. A spring hooking protrusion 30e and a rotation limiting groove 30f are formed on the outer periphery of the support frame 30 (FIG. 6).

  The insertion / removal frame 31 holds the wide converter lens WC in a cylindrical lens holding portion 31a, and extends a pair of arms 31b and 31c from the lens holding portion 31a in different directions, and is near the tip of the arm 31b. A shaft support 31d is formed. On the arm 31b, a spring engaging projection (support member) 31e and a pressed projection 31f are provided so as to project forward in the optical axis direction. The shaft support 31d is pivotally supported by a rotation shaft 31x parallel to the photographic optical axis O, and the insertion / removal frame 31 is an insertion position for inserting the wide converter lens WC onto the photographic optical axis O with the rotation shaft 31x as a center. 3, 4, 9, and 12) and the retracted position (the lower half section of FIGS. 1 and 2, FIGS. 7 and 10) where the wide converter lens WC is detached from the imaging optical axis O. Is possible. The insertion position of the insertion / removal frame 31 is determined by the vicinity of the tip of the arm 31c coming into contact with the stopper 30d of the support frame 30. A notch 19c that penetrates in the radial direction is formed at the front end portion of the rectilinear guide ring 19, and the insertion / removal frame 31 is retracted with a large amount of overlap in the optical axis direction between the rectilinear guide ring 19 and the second group support ring 20. When rotated to the position, a part of the lens holding portion 31a enters the cutout portion 19c (FIG. 1).

  The shaft support portion 31d of the insertion / removal frame 31 is inserted through the coil portion of the intermediate position holding spring 34 formed of a torsion spring. The outer peripheral surface of the shaft support portion 31d has a cylindrical shape, and the intermediate position holding spring 34 is supported to be rotatable relative to the shaft support portion 31d. A pair of spring arm portions 34a, 34b of the intermediate position holding spring 34 extending from the coil portion of the intermediate position holding spring 34 sandwich a spring engaging protrusion 31e formed on the arm 31b of the insertion / removal frame 31, and The position holding spring 34 applies a force for holding the insertion / removal frame 31 at an intermediate position (FIGS. 5, 8, and 11) between the insertion position and the retracted position. The insertion / removal frame 31 and the intermediate position holding spring 34 are pressed from the front by a holding member 35 that is screwed to the support frame 30, and the drop-off from the support frame 30 is restricted.

  A rotation operation between the intermediate position of the insertion / removal frame 31 and the insertion position is performed by the drive ring 32. The drive ring 32 is an annular body that surrounds the photographing optical axis O, and is held inside the circumferential wall 30 a of the support frame 30. The drive ring 32 is formed with two rotation guide grooves 32a through which the rotation guide protrusions 30c of the support frame 30 are slidably inserted in the optical axis direction. The rotation guide groove 32 a is a long groove in the circumferential direction centering on the photographing optical axis O, and the driving ring 32 is guided with respect to the support frame 30 by the rotation guide groove 32 a being guided by the rotation guide protrusion 30 c. It is supported rotatably about O. As shown in FIG. 6, a drive ring biasing spring (first drive) composed of a tension spring is applied to a spring hooking protrusion 30e provided on the support frame 30 and a spring hooking protrusion 32b protruding from the outer peripheral surface of the driving ring 32. One end portion and the other end portion of a mechanism (biasing member) 36 are hung, and the drive ring 32 is urged to rotate counterclockwise in FIGS. The drive ring 32 is provided with a drive protrusion 32 c protruding in the outer diameter direction, and the drive protrusion 32 c is inserted into the rotation limiting groove 30 f of the support frame 30. As shown in FIG. 6, the drive projection 32 c abuts on one end of the rotation limiting groove 30 f, thereby restricting the rotation of the drive ring 32 in the biasing direction by the drive ring biasing spring 36. This rotation restriction position of the drive ring 32 is referred to as an initial position. The drive ring 32 is further provided with a spring operation protrusion (protrusion) 32d that is inserted between the spring arm 34a and the spring arm 34b of the intermediate position holding spring 34. When the drive ring 32 is located at the initial position, the drive projection 32c does not press the spring arm 34a, and the insertion / removal frame 31 is held at the intermediate position by the force of the intermediate position holding spring 34 (FIGS. 8 and 11). .

  As shown in FIGS. 4 and 6 to 9, a control cam (first drive mechanism, drive control unit, circumferential cam) 37 is formed in the vicinity of the front end portion of the linear guide ring 19. The control cam 37 is a circumferential cam formed on the inner circumferential surface of the linear guide ring 19, and includes a concave portion 37a and a mountain-shaped pressing portion 37b that partially fills the concave portion 37a. Thus, the drive protrusion 32c of the drive ring 32 can come into contact. More specifically, when the linear guide ring 19 and the second group support ring 20 have a predetermined positional relationship in the optical axis direction, the drive protrusion 32c comes into contact with the pressing portion 37b, and the linear guide ring 19 and the second group in the corresponding state. When the support ring 20 relatively moves in the optical axis direction, the drive protrusion 32c is pressed along the inclined shape of the pressing portion 37b, and the drive ring 32 is rotated in a direction against the urging force of the drive ring urging spring 36. . Then, as shown in FIG. 12, the spring operation protrusion 32d presses the spring arm portion 34a to rotate the intermediate position holding spring 34, and the intermediate position holding spring 34 presses the spring engagement protrusion 31e by the spring arm portion 34b. Thus, the insertion / removal frame 31 is rotated to the insertion position. The insertion / removal frame 31 is stopped at the insertion position by bringing the arm 31c into contact with the stopper 30d.

  FIG. 12 shows a maximum pressing state in which the driving protrusion 32c is in contact with the pressing portion 37b at the position “B” in FIG. The amount of rotation of the drive ring 32 given by the pressing of the pressing portion 37b is set larger than the amount of rotation required to rotate the insertion / removal frame 31 from the intermediate position to the insertion position. In the state of FIG. As a result of the rotation of the drive ring 32 after the frame 31 is restricted from rotation at the insertion position, the distance between the spring arm portion 34b that engages with the spring engagement projection 31e and the spring arm portion 34a that engages with the spring operation projection 32d. The intermediate position holding spring 34 is bent (charged) in such a manner as to increase. In other words, the rotation amount of the drive ring 32 is set large so that the insertion / removal frame 31 can be reliably rotated to the insertion position even if there is some mechanical accuracy error. A difference in rotation amount between the frame 31 and the drive ring 32 is absorbed by deformation of the intermediate position holding spring 34. When the optical axis direction position of the drive ring 32 with respect to the linear guide ring 19 changes back and forth from the state in which the insertion / removal frame 31 is held at the insertion position, the pressing of the driving projection 32c by the pressing portion 37b is released, and the driving ring 32 is driven. Returning to the initial position of FIG. 6 by the biasing force of the ring biasing spring 36. Further, the bending of the intermediate position holding spring 34 is released, and the insertion / removal frame 31 returns from the insertion position to the intermediate position along with the drive ring 32.

  The drive ring 32 is held by a drive ring holding frame 33. The drive ring holding frame 33 is a C-shaped partial annular body that surrounds the photographing optical axis O. A pair of engagement holes 33a are formed in the vicinity of both ends in the circumferential direction, and a rearward direction in the optical axis is formed in an intermediate portion in the circumferential direction. A protruding engaging protrusion 33b is formed. A pair of engaging convex portions 30b provided on the support frame 30 is inserted into the pair of engaging holes 33a. Each engagement hole 33a is formed with a protrusion that engages with a radial through hole formed in the engagement protrusion 30b, and each engagement protrusion 30b is detached from each engagement hole 33a. Stopped. An engagement piece 30g (FIG. 6) with which a hook provided at the rear end in the optical axis direction of the engagement protrusion 33b engages is formed on the outer peripheral surface of the support frame 30. The drive ring holding frame 33 is fixedly supported with respect to the support frame 30 by these engaging portions. The drive ring 32 is rotatably supported between the support frame 30 and the drive ring holding frame 33.

  The rotation operation between the intermediate position and the retracted position of the insertion / removal frame 31 is performed by the relationship between the inner feeding cylinder 18 and the insertion / removal frame 31. As shown in FIGS. 6 to 10, a retraction drive rib (second drive mechanism, second drive control unit 40) is formed on the outer peripheral surface of the lens holding cylinder 18 a constituting the inner feeding cylinder 18. The retracting drive rib 40 is positioned on the rear end side of the retracting / holding portion 40a having a constant protrusion amount in the outer diameter direction and the retracting / holding portion 40a, and gradually protrudes in the outer diameter direction as it advances rearward in the optical axis direction. An inclined portion 40b for reducing the amount is provided, and the pressed protrusion 31f of the insertion / removal frame 31 can come into contact with the outer edge portion of the retracting holding portion 40a and the inclination portion 40b. Due to the change in the positional relationship in the optical axis direction (operation in which the inner feeding cylinder 18 moves rearward in the optical axis direction and the retracting drive rib 40 approaches the insertion / removal frame 31), the pressed protrusion 31f is applied to the inclined portion 40b. When in contact, the pressed protrusion along the inclined shape of the inclined portion 40b 10, the insertion / removal frame 31 is rotated from the intermediate position to the retracted position while pressing the spring arm 34b with the spring engagement protrusion 31e, as shown in FIG. The protrusion 31f is held at the retracted position by contacting the retracting holding portion 40a, and the drive ring 32 is not rotated when the inserting / removing frame 31 is rotated to the retracted position, and the spring engagement of the inserting / removing frame 31 rotated to the retracted position. The intermediate position holding spring 34 is bent (charged) in such a manner that the spring arm 34b pressed by the mating protrusion 31e increases the distance from the spring arm 34a abutting against the spring operation protrusion 32d of the drive ring 32 in a stopped state. In other words, when the intermediate position holding spring 34 is deformed, the insertion / removal frame 31 can be independently rotated to the retracted position without interlocking with the drive ring 32. Evacuation position When the position of the insertion / removal frame 31 in the optical axis direction with respect to the inner feeding cylinder 18 changes from the state held in the state and the pressing of the pressed protrusion 31f by the retracting drive rib 40 is released, the insertion / removal frame 31 is moved to the intermediate position holding spring. The urging force 34 returns the retracted position to the intermediate position.

  The zoom lens barrel 10 having the above structure operates as follows. In the lens barrel retracted state shown in FIG. 1, when a feed signal of the zoom lens barrel 10 (such as turning on a main switch of a camera on which the zoom lens barrel 10 is mounted) is input, the zoom motor moves in the barrel feed direction. When driven, the zoom gear rotates, and the outer feed cylinder 16 is guided by the guide groove 13a of the housing 13 and rotated forward. The rectilinear guide ring 19 moves straight forward together with the outer feeding cylinder 16. When the outer feed cylinder 16 rotates, the second group support ring 20 (second group lens block 17) guided linearly by the straight guide ring 19 due to the relationship between the second group control cam groove CG2 and the second group cam follower CF2. It is moved along a predetermined locus in the optical axis direction. When the outer feeding cylinder 16 rotates, the inner feeding cylinder 18 guided linearly through the linear guide ring 19 has a predetermined locus in the optical axis direction due to the relationship between the first group control cam groove CG1 and the first group cam follower CF1. Moved.

  The amount of extension of the first lens group LG1 and the second lens group LG2 from the lens barrel storage state is the amount of forward movement of the outer extension cylinder 16 relative to the housing 13, and the inner extension cylinder 18 and the second group support relative to the outer extension cylinder 16, respectively. It is determined as a total value with the cam feed amount of the ring 20. As shown in FIG. 2, when the zoom lens barrel 10 is in the shooting state, the first lens group LG1 and the second lens group LG2 move on the shooting optical axis O while changing the air interval between them. The focal length changes from the telephoto end to the telephoto end.

  When a storage signal of the zoom lens barrel 10 (such as turning off the main switch of the camera) is input, the zoom motor is driven in the lens barrel storage direction, and the zoom lens barrel 10 is retracted opposite to the above-described feeding operation. And the storage state shown in FIG. 1 is obtained.

  In addition, when the zoom lens barrel 10 is in the shooting state, the third group frame 15 supporting the third lens group LG3 is driven by the AF light by driving the AF motor in accordance with the subject distance information obtained by the distance measuring means. Moving along the axis O performs focusing.

  In the retracted state of the zoom lens barrel 10, the retracting holding portion 40a of the retracting drive rib 40 provided on the inner feeding cylinder 18 presses the pressed protrusion 31f, and the insertion / removal frame 31 is held at the retracted position (FIG. 1). FIG. 7 and FIG. 10). At this time, the drive protrusion 32c of the drive ring 32 is in the “A” position of FIG. 6 with respect to the control cam 37 of the linear guide ring 19, and the drive ring 32 is not pressed by the pressing portion 37b and the drive ring biasing spring 36 is driven. It is held at the initial position by the urging force. In the zoom lens barrel 10, the distance between the first lens group LG1 and the second lens group LG2 in the optical axis direction is reduced in order to reduce the thickness of the zoom lens barrel 10 in the retracted state, and the first lens group LG1 and the second lens group are arranged. A space for accommodating the wide converter lens WC cannot be obtained between LG2. Therefore, as shown in FIG. 1, the first lens is not interfered with the wide converter lens WC by moving the insertion / removal frame 31 to the retracted position where the wide converter lens WC is accommodated in the outer space of the first lens group LG1. The storage length of the zoom lens barrel 10 can be shortened by bringing the group LG1 and the second lens group LG2 close to each other. At this time, the wide converter lens WC and a part of the lens holding portion 31a enter the cutout portion 19c, thereby preventing the rectilinear guide ring 19 and the insertion / removal frame 31 from interfering with each other and realizing a retreat state with excellent space efficiency. .

  When the zoom lens barrel 10 is extended from the retracted state, the inner extension cylinder 18 has a larger amount of movement forward in the optical axis direction than the second group support ring 20 (second group lens block 17). Releases the pressure on the pressed protrusion 31f, and the holding of the insertion / removal frame 31 in the retracted position is released. Then, the insertion / removal frame 31 is rotated from the retracted position to the intermediate position by the biasing force of the intermediate position holding spring 34. When the zoom lens barrel 10 is further extended, the second group support ring 20 (second group lens block 17) is extended forward in the optical axis direction with respect to the linear guide ring 19, and the position of the drive protrusion 32c with respect to the control cam 37 is illustrated. 6 changes from the “A” position to the “B” position. Then, the pressing portion 37b presses the drive protrusion 32c, the drive ring 32 is rotated from the initial position against the urging force of the drive ring urging spring 36, and the insertion / removal frame 31 is inserted via the intermediate position holding spring 34. Rotate to position (FIGS. 3, 4, 9, 12). As a result, the wide converter lens WC is inserted on the photographing optical axis O, and a super-wide state is obtained in which the focal length is shorter than the wide end of the zoom lens system.

  When the zoom lens barrel 10 is extended from the super wide state, the second group support ring 20 (second group lens block 17) is extended forward in the optical axis direction with respect to the linear guide ring 19, and the drive protrusion 32c with respect to the control cam 37 is extended. The position changes from the “B” position in FIG. 6 to the “C” position. Then, the pressing of the driving projection 32c by the pressing portion 37b is released, the driving ring 32 returns to the initial position by the biasing force of the driving ring biasing spring 36, and the insertion / removal frame 31 rotates from the insertion position to the intermediate position ( 5, FIG. 8, FIG. 11). At the middle position of the insertion / removal frame 31, the wide converter lens WC is positioned outside the photographing optical path, and the wide converter lens WC is not involved in photographing.

  The “C” position shown in FIG. 6 is the driving end at the wide end (upper half section of FIG. 2) of the zoom lens barrel 10, and the “D” position is the driving projection at the tele end (lower half section of FIG. 2) of the zoom lens barrel 10. It is the position of 32c. As can be seen from FIG. 6, in the zoom range from the wide end to the tele end, the drive protrusion 32c is detached forward from the control cam 37, and the drive ring 32 continues to be held at the initial position. That is, the insertion / removal frame 31 is not rotated to the insertion position in the normal zoom range. In most of the zoom range, the insertion / removal frame 31 is held at the intermediate position by the intermediate position holding spring 34, but in the vicinity of the telephoto end shown in the lower half of FIG. 2, the light of the first lens group LG1 and the second lens group LG2 As the axial interval becomes smaller, the retracting drive rib 40 approaches the inserting / removing frame 31 and presses the pressed protrusion 31f with the retracting drive rib 40, and the inserting / removing frame 31 is rotated to the retracted position. . As in the retracted state, the distance between the first lens group LG1 and the second lens group LG2 becomes smaller at the telephoto end, and the space in the optical axis direction becomes narrower. Therefore, the first insertion / removal frame 31 is rotated to the retracted position. Interference between the lens group LG1 and the wide converter lens WC can be prevented.

  As described above, in the zoom lens barrel 10 of the present embodiment, as the mechanism for driving the insertion / removal frame 31 that holds the wide converter lens WC, the first drive mechanism for driving between the insertion position and the intermediate position. And a second drive mechanism for driving between the intermediate position and the retracted position. By sharing the drive range of the converter lens WC with the first drive mechanism and the second drive mechanism, it is possible to make each drive mechanism a small structure with less space and arrangement restrictions.

  For example, when the insertion / removal frame 31 is in the range from the insertion position to the intermediate position, the intermediate position holding spring 34 transmits the rotation of the drive ring 32 to the insertion / removal frame 31 by rotation about the rotation shaft 31x. When the unframe 31 rotates from the intermediate position to the retracted position, it functions as an urging means for returning the insertion / removal frame 31 to the intermediate position. Thereby, the length of the spring arm portions 34a and 34b can be shortened, and the intermediate position holding spring 34 can be downsized. Even if the intermediate position of the insertion / removal frame 31 is not set, the insertion / removal frame 31 is moved in the direction of the retraction position by a torsion spring whose amount of bending gradually increases as the insertion / removal frame 31 rotates from the retraction position to the insertion position. When energized, spring arm portions that are longer than the spring arm portions 34a and 34b of the intermediate position holding spring 34 of the present embodiment are required, and the drive mechanism becomes large.

  Further, by selectively using an intermediate position where the retracting amount of the wide converter lens WC is small and a retracting position where the retracting amount of the converter lens is large according to the extended state of the zoom lens barrel 10, the wide converter lens WC within the zoom lens barrel 10. The first drive mechanism and the second drive mechanism for driving the wide converter lens WC can be reduced in size and simplified. Specifically, in the retracted state of the zoom lens barrel 10 shown in FIG. 1 and in the vicinity of the tele end of the zoom lens barrel 10 shown in the lower half of FIG. 2, the light of the first lens group LG1 and the second lens group LG2 Since the axial interval is small, the insertion / removal frame 31 is rotated to the retracted position where it does not interfere with the first lens group LG1. The rotational drive of the insertion / removal frame 31 to the retracted position is performed by pressing the retracting drive rib 40 provided on the inner feeding cylinder 18 that holds the first lens group LG1, so that the inner feeding cylinder 18 moves in the optical axis direction. The insertion / removal frame 31 can be rotated with a simple configuration using force. As shown in FIG. 5, in the zoom range excluding the vicinity of the telephoto end, the insertion / removal frame 31 is held at the intermediate position by the small intermediate position holding spring 34. Further, in the super wide state between the wide end and the retracted state, the converter lens unit 22 is formed on the straight guide ring 19 by utilizing the fact that the converter lens unit 22 is closer to the straight guide ring 19 than the zoom range from the tele end to the wide end. The drive ring 32 is pressed and rotated by the pressing portion 37b of the control cam 37, and the insertion / removal frame 31 is rotated to the insertion position. The rotation amount that the drive ring 32 gives to the insertion / removal frame 31 is from the intermediate position to the insertion position, and the rotation amount of the drive ring 32 can be reduced as compared with the configuration that rotates from the retracted position to the insertion position.

  As mentioned above, although demonstrated based on illustration embodiment, this invention is not limited to this. For example, in the zoom lens barrel 10 of the embodiment, the optical element inserted into and removed from the photographing optical axis O is the wide converter lens WC, but the present invention is a teleconverter lens driving mechanism that makes the focal length longer than the tele end. It is also possible to use. The zoom lens system of the zoom lens barrel 10 is a wide end when the extension operation is performed from the retracted state, and a tele end when the extension operation is further performed. In the case of this zoom lens system, the teleconverter lens can be driven by the same drive mechanism as in the illustrated embodiment.

  In the zoom lens barrel 10 of the embodiment, the insertion / removal frame 31 is moved to the insertion position in the middle of the zoom range from the housed state, but the converter lens is inserted on the optical axis at a position extended from the zoom range. It is also possible to apply the present invention to a lens barrel of the type.

  In the zoom lens barrel 10 of the embodiment, the insertion / removal frame 31 and the drive ring 32 are rotationally driven by the inner feeding cylinder 18 and the rectilinear guide ring 19 that move linearly in the optical axis direction. A configuration in which a driving force is applied to the drive mechanism of the converter lens by a rotating member such as the outer feeding cylinder 16 instead of the rectilinearly moving member may be employed.

  The present invention can also be applied to zoom lens systems other than the three-group configuration such as the zoom lens barrel 10 of the embodiment. The insertion position of the converter lens can be set other than between the first lens group LG1 and the second lens group LG2.

DESCRIPTION OF SYMBOLS 10 Zoom lens barrel 11 Optical filter 12 Image pick-up element 13 Housing 14 Image pick-up element holder 15 3 group frame 16 Outer delivery cylinder 17 2nd lens block 18 Inner delivery cylinder (2nd relative movement member)
18a Lens holding cylinder 19 Linear guide ring (relative movement member)
20 Group 2 support ring (support member)
21 Shutter unit (supporting member)
22 Converter lens unit 30 Support frame (support member)
30a Circumferential wall 30b Engaging protrusion 30c Rotating guide protrusion 30d Stopper 30e Spring hooking protrusion 30f Rotation limiting groove 30g Engaging piece 31 Inserting / removing frame 31a Lens holding part 31b 31c Arm 31d Shaft support 31e Spring engaging protrusion (protruding part) )
31f Pressed protrusion 31x Rotating shaft 32 Drive ring (first drive mechanism, rotation drive member)
32a Rotation guide groove 32b Spring hooking protrusion 32c Drive protrusion 32d Spring operation protrusion (protrusion)
33 Drive ring holding frame 33a Engaging hole 33b Engaging projection 34 Intermediate position holding spring (torsion spring)
34a 34b Spring arm portion 35 Holding member 36 Drive ring biasing spring (first driving mechanism, biasing member)
37 control cam (first drive mechanism, drive control unit, circumferential cam)
37a Concave part 37b Pressing part 40 Retraction driving rib (second driving mechanism, second driving control part)
40a Retraction holding portion 40b Inclination portion CF1 First group cam follower CF2 Second group cam follower CG1 First group control cam groove CG2 Second group control cam groove LG1 First lens group LG2 Second lens group LG3 Third lens group O Shooting optical axis S Shutter WC Wide converter lens

Claims (10)

A zoom lens system including a plurality of lens groups moving in the optical axis direction and having a variable focal length;
A converter lens that is inserted on the optical axis of the zoom lens system to enable photographing at a focal length outside the focal length range of the zoom lens system; and the converter lens onto the optical axis of the zoom lens system. A converter lens drive mechanism that moves between the insertion position of the lens and the retracted position separated from the optical axis;
In a lens barrel with
The converter lens drive mechanism is
A first drive mechanism that moves the converter lens between the insertion position and an intermediate position that is intermediate between the insertion position and the retracted position and does not interfere with the imaging optical path of the zoom lens system; and the converter lens A second drive mechanism for moving the motor between the intermediate position and the retracted position;
Have
In the retracted state of the lens barrel that is not photographed, the converter lens is positioned at the retracted position by the second driving mechanism, and the first driving mechanism is at least partly in the focal length range of the zoom lens system. The lens barrel is characterized in that the converter lens is positioned at the intermediate position. The lens barrel according to claim 1,
An insertion / removal frame for holding the converter lens;
A support member that rotatably supports the insertion / removal frame about a rotation axis parallel to the optical axis of the zoom lens system; and a relative movement with respect to the support member when the plurality of lens groups are moved in the optical axis direction. Relative movement member to perform;
Have
The first drive mechanism includes:
A rotation drive member supported by the support member and configured to move the insertion / removal frame to the insertion position and the intermediate position of the converter lens by rotation about an axis parallel to a rotation axis of the insertion / removal frame; A drive control unit that is formed on the relative movement member and changes the position of the rotation drive member in the rotation direction by contacting and releasing the rotation drive member by relative movement of the relative movement member with respect to the support member;
A lens barrel. 3. The lens barrel according to claim 2, wherein the first drive mechanism includes a biasing member that holds the rotation drive member at an initial position corresponding to the intermediate position of the converter lens,
The drive control unit abuts on the rotation drive member by relative movement of the support member and the relative movement member, and rotates the rotation drive member from the initial position against the biasing force of the insertion biasing member. The lens barrel to be made. 4. The lens barrel according to claim 2, wherein the relative movement member is supported so as to be linearly movable in the optical axis direction, and light is applied to the support member when the plurality of lens groups are moved in the optical axis direction. A lens barrel that moves in the axial direction. 5. The lens barrel according to claim 4, wherein the relative movement member is a rectilinear guide ring that guides the support member so as to be movable in an optical axis direction, and the drive control unit is formed on a peripheral surface of the rectilinear guide ring. A lens barrel made of a circumferential cam. 6. The lens barrel according to claim 2, wherein the protrusion provided on the insertion / removal frame and the protrusion provided on the rotation drive member are inserted between a pair of spring arm portions, and the insertion is performed. Having a torsion spring rotatable around the rotation axis of the unframed,
The lens barrel in which the insertion / removal frame is held at the intermediate position of the converter lens by the torsion spring, and the rotational force of the rotation driving member is transmitted to the insertion / removal frame via the pair of spring arms. . 7. The lens barrel according to claim 6, wherein the second drive mechanism is formed on a second relative movement member that moves relative to the support member when the plurality of lens groups are moved in the optical axis direction. A second movement of the second relative movement member with respect to the support member causes contact and release of the insertion / removal frame, and presses the insertion / removal frame to move the converter lens to the retracted position. A lens barrel having a drive control unit. 8. The lens barrel according to claim 7, wherein the second relative movement member is supported so as to be linearly movable in the optical axis direction, and moves relative to the support member when the plurality of lens groups are moved in the optical axis direction. A lens barrel that moves relative to the optical axis. 9. The lens barrel according to claim 8, wherein the second relative movement member is a cylindrical member having therein a lens holding cylinder portion that holds at least one of the plurality of lens groups, and the second driving unit. The control unit is a lens barrel including a protruding portion protruding in the outer diameter direction from the lens holding tube portion. The lens barrel according to claim 9, wherein the support member holds at least one of the plurality of lens groups,
The lens group held by the second relative movement member is located closer to the subject than the lens group held by the support member,
The converter lens is a lens barrel inserted between the lens group held by the second relative movement member and the lens group held by the support member.

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