JP2005208633A - Lens barrel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lens barrel in which, when a motor is driven, this driving force can be surely transmitted to a movable lens and in which, after the movable lens is moved by the driving force of the motor, the movable lens can be smoothly moved by a manual operation ring, with respect to a lens barrel in which the movable lens can be transferred in the optical axis direction both by the driving force of the motor and by the torque of the manual operation ring. <P>SOLUTION: The lens barrel is characterized in that, when a torque is inputted in a rotary input/output shaft 15 and a relative rotational torque, i.e., a differential in the torque of the rotary output shaft and the rotary input shaft, becomes greater than a predetermined torque, the associating devices 15g, 21a cause a clutch member to relatively transfer against a pressing force of a second pressing means 23 to release engagement in the circumferential direction between the clutch member and a torque transfer member. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a lens barrel.

  As a lens barrel that can be focused by either autofocus (AF) or manual focus (MF), a fixed ring and a concentric movement with this fixed ring, holding the focus lens, can move forward and backward in the optical axis direction. A ring, a distance adjusting ring that is concentric with the fixed ring and rotates around the axis thereof to move the moving ring back and forth in the optical axis direction, an AF motor that rotates the distance adjusting ring, and an axis around the axis And a manual focus ring that rotates the distance adjustment ring by rotating the distance adjustment ring.

Between the distance adjusting ring of the lens barrel and the AF motor, the driving force of the AF motor is transmitted to the distance adjusting ring, but the rotational force of the distance adjusting ring rotated by the manual focus ring is Some have a one-way input / output rotation transmission mechanism that does not transmit to the AF motor.
As a prior art of such a lens barrel, for example, there is Patent Document 1, and if the lens barrel has such a configuration, MF shooting is performed while the AF switch is turned on and AF shooting is possible. be able to.
JP-A-11-202181

  However, in the lens barrel of Patent Document 1, when the AF motor is rotated, the one-way input / output rotation transmission mechanism cannot reliably transmit the rotational torque from the AF motor to the distance adjustment ring. , AF may not be performed.

  An object of the present invention is to provide a lens barrel in which a moving lens can be moved in the optical axis direction by either a driving force by a motor or a manually rotating force of a manual operation ring. An object of the present invention is to provide a lens barrel that can be reliably transmitted to a moving lens and that can be smoothly moved by a manual operation ring after the moving lens is moved by a driving force of a motor.

  The lens barrel of the present invention includes a manual operation ring that moves the moving lens in the optical axis direction by manual rotation operation, a motor that drives the moving lens in the optical axis direction, and the driving force when the motor is driven. And a first one-way input / output rotation transmission mechanism that does not transmit the moving force of the moving lens to the motor when the manual operation ring is rotated. The first one-way input / output rotation transmission mechanism has a first axially orthogonal plane orthogonal to an axis parallel to the optical axis, and an input rotary shaft that is rotationally driven by the motor, and the input rotation An output rotary shaft that is rotatable relative to the shaft around the axis, and whose rotational movement and movement of the moving lens in the optical axis direction are interlocked with each other. , Output rotation above And a cylindrical clutch member having an inner peripheral surface thereof as an inner peripheral contact surface and a circumference centered on the axis of the input rotation shaft, The urging means is always brought into contact with the first axially orthogonal plane, and in the same direction while being delayed with respect to the input rotating shaft around the axis of the input rotating shaft in conjunction with the rotation of the input rotating shaft. A first circumferentially unequal width space having an unequal width in the circumferential direction is formed between the first differential rotating member that revolves and the inner peripheral surface of the clutch member formed on the outer peripheral surface of the input rotating shaft. A first circumferentially unequal width space forming portion to be formed, and a first differential that is movably inserted into the first circumferentially unequal width space and interlocked with the first differential rotation member; A first rotational force transmitting member having a circular contact surface in cross section that revolves in the same direction as the rotating member and is capable of contacting the inner peripheral contact surface of the clutch member. The clutch member is normally biased in a direction to increase the frictional force between the inner peripheral contact surface of the clutch member and the circular contact surface of the first rotational force transmitting member, and the clutch member Second urging means for preventing relative movement with respect to the output rotating shaft, and linking means for transmitting the rotational force generated in one of the clutch member or the output rotating shaft to the other. When the rotational force is input to the input rotation shaft, the circumferential direction unequal width space forming portion rotates in the circumferential direction in conjunction with the input rotation shaft and the first differential rotation member. The rotational force transmission member of 1 is bitten between the first circumferential direction unequal width space forming portion and the clutch member while the circular contact surface of the cross section is in contact with the inner peripheral contact surface, and the input rotation is performed. Shape integrated with the shaft and the clutch member in the circumferential direction When the rotational force is input to the input rotational shaft, the linkage means transmits the rotational force from the clutch member integrated with the input rotational shaft to the output rotational shaft. When a rotational force is input to the output rotation shaft and the relative rotation torque, which is the difference between the rotation torque of the output rotation shaft and the rotation torque of the input rotation shaft, is greater than a predetermined torque determined by the shape of the linkage means, The clutch member is moved relative to the output rotating shaft in a direction to reduce the frictional force against the urging force of the second urging means, and the circumferential direction of the clutch member and the rotating force transmitting member It is characterized by releasing the integrated state.

  The linking means regulates the relative movement of the clutch member with respect to the output rotation shaft when the rotational force is input to the input rotation shaft and the relative rotation torque is equal to or less than the predetermined torque, and the relative rotation is performed. When the torque becomes larger than the predetermined torque, the clutch member is temporarily allowed to move relative to the output rotation shaft, and then the clutch member is urged by the urging force of the second urging means. Is allowed to return to the initial position, and this state is maintained thereafter.

  In the link means, when the first rotational force transmission member does not bite between the first circumferentially unequal width space forming portion and the clutch member, rotational force is input to the output rotation shaft. It is practical not to move the clutch member relative to the output rotation shaft.

  An annular space having the first circumferential unequal width space is formed between the input rotation shaft and the clutch member, and the annular space receives the rotational force of the first differential rotation member, It is practical to insert an annular retainer that rotates in the same direction as the first differential rotation member, and hold the first rotational force transmission member on the retainer.

  A first pressing surface which is opposed to and parallel to the first axially orthogonal surface to the first pressing member which is always urged toward the first axially orthogonal surface by the first urging means. Preferably, the first differential rotation member is sandwiched between the first pressing surface and the first axially orthogonal surface.

It is practical that the linkage means comprises a power transmission pin formed on one of the clutch member and the output rotation shaft, and a power transmission hole in which the power transmission pin formed on the other is loosely fitted.
In this case, the predetermined torque is determined by the shape of the power transmission hole and the power transmission pin.

  If the inner peripheral contact surface is a first tapered surface, and the circular cross-sectional contact surface is a second tapered surface that is inclined in substantially the same direction as the first tapered surface, the first rotational force transmitting member And the integration of the clutch member in the circumferential direction and the cancellation of the integration can be performed smoothly.

  The first rotational force transmission member is preferably a conical member having a cut head, and in this way, the transmission efficiency of rotational force from the input rotation shaft to the clutch member is improved. .

  The first differential rotation member is preferably a differential roller having a substantially cylindrical shape whose rotation axis faces the radial direction of the input rotation axis. In this case, the first differential rotation member extends from the input rotation axis to the first differential rotation member. The transmission efficiency of the rotational force to the rotational force transmission member is improved.

  The first differential rotating member may be a spherical differential bearing ball.

  The first circumferential unequal width space forming portion forms a plurality of the first circumferential unequal width spaces with the inner circumferential contact surface of the clutch member. It is preferable that the first rotational force transmitting members are respectively inserted into the circumferentially unequal width spaces.

  The first circumferential unequal width space forming portion may be a first unequal width groove having a different radial depth depending on a circumferential position.

  A distance adjusting ring that rotates around the axis of the rotating shaft by receiving a rotating force from the manual operation ring or receiving a rotating force from the output rotating shaft and moves the moving lens in the optical axis direction. Between the adjustment ring and the manual operation ring, the rotational force of the manual operation ring is transmitted to the distance adjustment ring, but the rotational force of the distance adjustment ring is not transmitted to the manual operation ring. It is preferable to provide a rotation transmission mechanism.

When the second one-way input / output rotation transmission mechanism is provided as described above, the second one-way input / output rotation transmission mechanism is provided on the manual operation ring. The second one-way input / output rotation transmission mechanism is perpendicular to the optical axis. An axially orthogonal surface, a ring-shaped overlapping portion that overlaps with the distance adjusting ring in a radial direction, and a rotation transmission that faces the ring-shaped overlapping portion of the manually operated ring formed on the inner peripheral surface or the outer peripheral surface of the distance adjusting ring. A second circumferential direction that forms a second circumferentially unequal width space having an unequal width in the circumferential direction between the cylindrical surface and the rotation transmitting cylindrical surface formed in the annular overlapping portion of the manual operation ring. Inserted into the unequal width space forming portion and the second circumferential unequal width space, and always brought into contact with the second axially orthogonal surface by the third biasing means, the manual operation ring In conjunction with the rotation, the second circumferentially unequal width space forming portion is moved around the axis of the manual operation ring, A second differential rotating member that revolves in the same direction while being delayed from the operation ring, and is inserted into the second circumferentially unequal width space and pushed by the second differential rotating member, thereby The second rotational force transmitting member that revolves in the same direction as the differential rotational member of the second rotational force transmitting member, wherein the second circumferential unequal width space forming portion rotates in the circumferential direction. However, it is practical to form a shape that bites between the second circumferentially unequal width space forming portion and the rotation transmission cylindrical surface to transmit the rotational force of the manual operation ring to the distance adjustment ring.

  It is practical to insert the second rotational force transmitting members side by side in the circumferential direction so as to sandwich the second differential rotating member as a pair in the second circumferentially unequal width space. .

  It is practical that at least a part of the second circumferentially unequal width space forming portion is constituted by a second unequal width groove having a different radial depth depending on the circumferential position.

  A second pressing surface that is opposed to and parallel to the second axially orthogonal surface to the second pressing member that is constantly urged toward the second axially orthogonal surface by the third urging means. Preferably, the second differential rotating member is sandwiched between the second pressing surface and the second axially orthogonal surface.

  The second circumferential unequal width space forming portion forms a plurality of the second circumferential unequal width spaces between the rotation transmitting cylindrical surfaces of the distance adjusting ring, It is practical to insert the second differential rotating member and the second rotational force transmitting member into the circumferentially unequal width space.

  The second rotational force transmitting member is preferably a columnar member that faces in a direction parallel to the axis of the manual operation ring, and in this way, the rotational force is transmitted from the manual operation ring to the distance adjustment ring. Efficiency is improved.

  By using the moving lens as a focus lens, the motor as an AF motor, and the manual operation ring as a manual focus ring, the lens barrel can be made into a focus lens barrel.

  The lens barrel can be a zoom lens barrel by using the moving lens as a zoom lens, the motor as a zoom motor, and the manual operation ring as a zoom ring.

  According to the present invention, in a lens barrel that can move a moving lens in the optical axis direction by either a driving force by a motor or a manual rotating force of a manual operation ring, the driving force is moved when the motor is driven. It can be transmitted to the lens reliably.

FIGS. 1 to 7 show a first embodiment in which the present invention is applied to a lens barrel 100 that can switch the photographing state between auto focus (AF) and manual focus (MF).
First, the overall configuration of the lens barrel 100 will be described.

  A first fixed ring 102 formed with a bayonet portion 102a to be attached to a camera body (not shown) at the rear end (explained with the left side of FIG. 1 as “front” and the right side of FIG. 1 as “rear”); The rear ends of the second fixed ring 104 that are concentric with the first fixed ring 102 and located on the inner peripheral side thereof are fixed by a fixing screw 106, and the front end of the inner peripheral surface of the second fixed ring 104 The fixed lens L1 is held in the part. The longitudinal length of the second fixed ring 104 is longer than that of the first fixed ring 102, and the three fixed guide grooves 104a are provided in the second fixed ring 104 at equal angular intervals in the circumferential direction. Between the rear portions of the first fixed ring 102 and the second fixed ring 104, an annular arrangement space S is formed in a front view, and a manual concentric with the first fixed ring 102 is formed in the arrangement space S. A focus ring (manual operation ring) 108 is disposed so as to be rotatable around the optical axis O. The rotation operation portion 108 a that forms the front end portion of the manual focus ring 108 is located in an annular space formed between the front end portion of the first fixed ring 102 and the front end portion 104 b of the second fixed ring 104. A cam groove 108b that is inclined with respect to each straight guide groove 104a is formed at a position corresponding to the straight guide groove 104a of the manual focus ring 108, and an inner peripheral surface of a rear end portion of the manual focus ring 108 is further formed. An input gear 108c is formed as a whole.

  On the inner peripheral side of the second fixed ring 104, a moving ring 110 that is concentric with the first fixed ring 102 is disposed so as to be movable back and forth in the direction of the optical axis O and not rotatable around the optical axis O. The ring 110 holds a focus lens (moving lens) L2. Three radial protrusions 110a are provided on the outer peripheral surface of the moving ring 110 at equal angular intervals in the circumferential direction. A roller 114 is attached to the tip of the moving ring 110 via an attachment screw 112. Yes. The rollers 114 are fitted in the overlapping portions of the cam grooves 108b corresponding to the straight guide grooves 104a. When the manual focus ring 108 rotates, the moving ring 110 (focus lens L2) is moved in the straight guide grooves. Advancing and retreating in the direction of the optical axis O along 104a.

An AF motor (motor) M is embedded in the rear wall 102b of the first fixed ring 102, and the rotation shaft M1 and the pinion P fixed to the rotation shaft M1 are located in the arrangement space S. . In the arrangement space S, a one-way input / output rotation transmission mechanism (first one-way input / output rotation transmission mechanism) U1 for linking the pinion P and the input gear 108c of the manual focus ring 108 is arranged. ing.
Next, the structure of the one-way input / output rotation transmission mechanism U1 will be described in detail mainly with reference to FIGS.

  The cylindrical housing 3 whose front end is closed and whose rear end is open has an annular flange 3a at its rear end, and this annular flange 3a is fixed to the first fixed ring 102 by a screw (not shown). ing. A circular plate 3c is fixed to the center of the rear surface of the front wall 3b of the housing 3, and a front end surface of the rotary shaft 5 coaxial with the housing 3 is fixed to the rear surface of the circular plate 3c. The rotating shaft 5 includes a front small diameter portion 5 a and a rear large diameter portion 5 b, and the axial direction of the rotating shaft 5 is parallel to the optical axis O.

  A center hole 7a of a cylindrical input rotation shaft 7 is rotatably fitted to the large diameter portion 5b. The input rotary shaft 7 is formed with a storage recess 7b that is annular when viewed from the front (when viewed from the axial direction), and a cylindrical small-diameter portion 7c having a center hole 7a is formed on the inner peripheral side of the storage recess 7b. The front surface of the small-diameter portion 7c is formed in an annular shape when viewed from the front (when viewed from the axial direction) and is orthogonal to the linear axis of the rotating shaft 5 (first axial orthogonal surface) ) 7c1. A rear wall 7d having an annular shape in front view is connected to the rear end portion of the small diameter portion 7c, and an outer peripheral wall 7e having an annular shape in front view is connected to the outer peripheral portion of the rear wall 7d. As shown in FIG. 4, on the outer peripheral surface of the small-diameter portion 7c, unequal width grooves (first circumferential direction unequal width space forming portions) (first circumferential direction space forming portions) (first circumferential direction) differing in the depth (distance in the radial direction) depending on the circumferential direction. (Unequal width grooves) 7c2 are formed at equal angular intervals. An annular step 7f is formed on the inner peripheral side end of the front surface of the rear wall 7d, and an input gear 7g is formed on the outer peripheral surface of the outer peripheral wall 7e.

The input rotary shaft 7 is housed in the housing 3 at a portion located in front of the input gear 7g. An annular recess 7h is formed at the center of the rear end surface of the input rotary shaft 7, and a plurality of metal bearing balls (steel balls) 9 are arranged in the annular recess 7h in a circumferential direction. Has been. A circular retaining plate 11 having a diameter substantially the same as that of the annular recess 7 h is fixed to the rear end surface of the rotating shaft 5 by a fixing screw 13, and each bearing ball 9 abuts against the retaining plate 11, Further rearward movement of the input rotating shaft 7 is restricted.
Further, an AF motor M is attached to the annular flange 3a of the housing 3, and the pinion P fixed to the rotation shaft M1 of the AF motor M meshes with the input gear 7g of the input rotation shaft 7. Yes.

Inside the housing 3, a front output and a rear end are both opened, and a cylindrical output rotating shaft 15 having a small diameter cylindrical portion 15 a forming the front portion and a large diameter cylindrical portion 15 b forming the rear portion is disposed. The center hole 15 c is loosely fitted to the rotating shaft 5. The front end portion of the center hole 15c is fitted to the circular plate 3c so as to be rotatable, and an output gear 15d is provided on the entire outer peripheral surface of the small diameter cylindrical portion 15a. The output gear 15d is exposed to the outside of the housing 3 through a window hole 3d formed in the front end portion of the housing 3, and meshes with the input gear 108c of the manual focus ring 108 (see FIG. 1).
Further, an annular protrusion 15e that is annular in a front view is projected from the rear end surface of the large-diameter cylindrical portion 15b, and the outer peripheral surface of the large-diameter cylindrical portion 15b is orthogonal to the axis of the rotary shaft 5. An annular flange 15f is provided.

  An annular member (first pressing member) 17 located in front of the input rotation shaft 7 is fitted on the large diameter portion 5 b of the rotation shaft 5. A compression coil spring (first urging means) 19 is provided between the front surface of the annular member 17 and the rear surface of the circular plate 3c. The compression coil spring 19 causes the annular member 17 to be always rearward ( It is biased toward the axial direction orthogonal surface 7c1 side). The rear surface of the annular member 17 is a pressing surface (first pressing surface) 17a parallel to the axially orthogonal surface 7c1.

Between the axial direction orthogonal surface 7c1 of the input rotating shaft 7 and the pressing surface 17a of the annular member 17, an annular arrangement space CS having an annular shape in front view is formed.
A cylindrical clutch member 21 that is concentric with the output rotation shaft 15 and that is open at both front and rear ends is disposed on the outer peripheral side of the output rotation shaft 15. As shown in FIGS. 6 and 7, the clutch member 21 has two substantially triangular engagement holes (power transmission holes) that are shifted by 180 ° in the circumferential direction (only one is shown in FIGS. 6 and 7). Linking means) 21a is perforated, and each engagement hole 21a has two radial projections (power transmission pins) projecting from the outer peripheral surface of the output rotary shaft 15 (only one is shown in the figure). (Linking means) 15g is loosely fitted, and the clutch member 21 can move relative to the output rotating shaft 15 in the front-rear direction and the circumferential direction by the clearance of the engagement hole 21a and the radial protrusion 15g. The rear end portion of the clutch member 21 is provided with a radially outward annular flange 21b. Between the annular flange 21b and the annular flange 15f, the clutch member 21 has a predetermined strength that always urges the clutch member 21 backward. A compression coil spring (second urging means) 23 is contracted. The rear end portion of the inner peripheral surface of the clutch member 21 is a tapered inner peripheral surface (inner peripheral contact surface) whose center is the linear axis of the rotating shaft 5 and whose diameter increases toward the rear. (First taper surface) 21c.
A storage space (first circumferential unequal width) between the tapered inner circumferential surface 21c of the clutch member 21 and each unequal width groove 7c2 as shown in FIG. Space) S1 is formed.

  Between the taper-shaped inner peripheral surface 21c and the small diameter portion 7c, an annular space RS having a ring shape when viewed from the front is formed. As shown in FIG. 2, the annular space RS is separated from the annular arrangement space CS described above. Communicate. The rear end of the annular arrangement space CS and the annular space RS is opened, and an insertion hole 25b drilled in the center of the front wall 25a is rotatably fitted to the rotary shaft 5, and thereafter A cylindrical retainer 25 whose end is rotatably fitted to the annular step 7f is disposed. As shown in FIG. 3, the front wall 25a of the retainer 25 is formed with three fitting holes 25c arranged at equal angular intervals in the circumferential direction around the insertion hole 25b. A spherical differential bearing ball (first differential rotating member) 27 is rotatably fitted in the hole 25c. The front end of the differential bearing ball 27 protrudes forward of the front wall 25a, and the rear end portion protrudes rearward of the front wall 25a. The front end of the differential bearing ball 27 is a pressing surface 17a parallel to the axial orthogonal surface 7c1 that forms the rear surface of the annular member 17 that is urged toward the rear (axial orthogonal surface 7c1 side) by the compression coil spring 19. Therefore, the rear end of the differential bearing ball 27 is in contact with an axially orthogonal surface 7c1 formed on the input rotating shaft 7, and the differential bearing ball 27 is in contact with the pressing surface 17a of the annular member 17. It is always clamped by the axial orthogonal surface 7c1.

Six mounting holes 25e are formed in the cylindrical portion 25d of the retainer 25 so as to be arranged at equal angular intervals in the circumferential direction. Each mounting hole 25e has a conical shape with the head cut off, and a biting roller (first rotational force transmitting member) 29 whose central axis (rotating axis) C1 faces substantially in the front-rear direction is center axis C1. It is inserted so as to be rotatable around and slightly movable in the direction of the central axis C1, and the outer peripheral surface of each biting roller 29 is a tapered outer peripheral surface (cross-sectional contact surface) (second tapered surface) 29a. Yes. As shown in FIGS. 2 and 4, each biting roller 29 has a part of the tapered outer peripheral surface 29a always in contact with the corresponding unequal width groove 7c2, and the clutch member 21 of the tapered outer peripheral surface 29a. Is inclined in the same direction as the tapered inner peripheral surface 21c.
Further, although not shown, the lens barrel 100 is provided with an AF switch that enables or disables AF shooting.

Next, the operation of the lens barrel 100 having the above configuration will be described.
First, the operation of the lens barrel 100 when performing focusing by AF will be described.
First, the AF switch is turned on so that AF shooting is possible. When a control circuit (not shown) provided in the camera body sends a forward rotation signal to the AF motor M, and the AF motor M rotates forward, the rotational force is input via the pinion P and the input gear 7g to the input rotation shaft. 7 and the input rotation shaft 7 rotates counterclockwise in FIGS. At this time, if no slip occurs between each differential bearing ball 27 and the pressing surface 17a and the axially orthogonal surface 7c1, each differential bearing ball 27 has a rotational speed that is ½ of the input rotational shaft 7. Thus, it revolves (rotates) around the axis of the input rotation shaft 7 in the same direction as the input rotation shaft 7. As a result, each differential bearing ball 27 rotates relative to the input rotation shaft 7 in the clockwise direction. Since the retainer 25 and each biting roller 29 rotate together with the bearing ball 27, the biting roller 29 located at the center portion (the deeply recessed portion) of the unequal width groove 7c2 corresponds to each unequal width groove 7c2. Between the tapered inner peripheral surface 21c and the tapered outer peripheral surface 29a, and the bite between the tapered inner peripheral surface 21c and the tapered outer peripheral surface 29a. A strong wedge force (frictional force) is generated. As a result, the small diameter portion 7c (input rotation shaft 7) and the clutch member 21 are integrated in the circumferential direction via the biting roller 29, so that the rotational force of the small diameter portion 7c is transmitted to the clutch member 21, and the clutch member 21 is Rotates counterclockwise.

  At this time, the radial protrusion 15g of the output rotating shaft 15 and the engagement hole 21a of the clutch member 21 are moved by the biasing force of the compression coil spring 23 as shown in FIG. Since the relationship of engaging the front end with the narrowest direction width is maintained, when the clutch member 21 rotates, the output rotating shaft 15 immediately rotates counterclockwise. Then, the output gear 15d formed on the output rotation shaft 15 rotates, and this rotational force is transmitted to the input gear 108c of the manual focus ring 108 of the lens barrel 100, and the focus lens L2 moves forward along the optical axis. Moving.

On the other hand, when the control circuit sends a reverse rotation signal to the AF motor M to reverse the AF motor M, the rotational force is transmitted to the input rotary shaft 7 via the pinion P and the input gear 7g, and the input rotary shaft 7 is It rotates in the clockwise direction of FIGS. Then, each differential bearing ball 27 sandwiched between the pressing surface 17a of the annular member 17 and the axially orthogonal surface 7c1 rotates at the same speed as the input rotating shaft 7 at a rotational speed ½ that of the input rotating shaft 7 while rotating. As a result, each differential bearing ball 27 rotates relative to the input rotation shaft 7 in the counterclockwise direction. Since the retainer 25 and each biting roller 29 rotate together with the bearing ball 27, the biting roller 29 includes a clutch member and an end portion on the counterclockwise side where the radial width of each unequal width groove 7c2 is narrow. It bites in with a strong force between the tapered inner peripheral surface 21c of 21. As a result, the small diameter portion 7c (input rotation shaft 7) and the clutch member 21 are integrated in the circumferential direction via the biting roller 29, the retainer 25, and the differential bearing ball 27, so that the rotational force of the small diameter portion 7c is reduced. The clutch member 21 is transmitted to the clutch member 21 and rotates in the clockwise direction. Also in this case, since the radial protrusion 15g of the output rotating shaft 15 and the engagement hole 21a of the clutch member 21 have the relationship shown in FIG. 6, when the clutch member 21 rotates, the output rotating shaft 15 immediately rotates clockwise. Then, the output gear 15d formed on the output rotation shaft 15 rotates, and this rotational force is transmitted to the input gear 108c of the manual focus ring 108 of the lens barrel 100, and the focus lens L2 moves rearward along the optical axis. Moving.
Thus, AF is performed by the control circuit rotating the AF motor M in both forward and reverse directions and moving the focus lens L2 back and forth.

As described above, the biting roller 29 has a strong force between the counterclockwise end where the radial width of each unequal width groove 7 c 2 is narrow and the tapered inner peripheral surface 21 c of the clutch member 21. After the bite and the small diameter portion 7c (input rotation shaft 7) and the clutch member 21 are integrated in the circumferential direction via the biting roller 29, the retainer 25, and the differential bearing ball 27, the AF operation is performed as follows. To be done.
When a signal in the direction opposite to the rotation direction immediately before the biting roller 29 bites into the AF motor M from the control circuit, the input rotary shaft 7 rotates. At this time, the relative rotational torque, which is the difference between the rotational torque of the input rotational shaft 7 and the rotational torque of the output rotational shaft 15 (smaller when the rotational directions of the input rotational shaft 7 and the output rotational shaft 15 are the same, and the rotational direction is reversed. When the input rotary shaft 7 and the output rotary shaft 15 receive the same rotational torque in the same direction, it becomes 0), but the shape of the radial projections 15g and the engagement holes 21a (linking means) 6), the radial projection 15g of the output rotating shaft 15 and the engagement hole 21a of the clutch member 21 maintain the relationship shown in FIG. 6 (the clutch member 21 is a compression coil). The movement of the spring 23 against the urging force of the spring 23 is restricted), and the biting roller 29 rotates relative to the clutch member 21 together with the input rotary shaft 7 as the input rotary shaft 7 rotates. , Of the eating roller 29 Bites for diameter portion 7c and the tapered inner peripheral surface 21c is released. Then, the input rotating shaft 7 and the biting roller 29 continue to rotate, and the biting roller 29 has a taper shape of the end of the unequal width groove 7c2 in the clockwise direction and the clutch member 21. Since a strong force bites into the inner peripheral surface 21c, the output rotation shaft 15 rotates in the same direction together with the input rotation shaft 7, and the focus lens L2 moves along the optical axis.

On the other hand, when the control circuit sends a signal in the direction opposite to the rotation direction immediately before the biting roller 29 bites into the AF motor M, the manual focus ring 108 is prevented from rotating by the photographer's hand. When the relative rotational torque becomes larger than the predetermined torque as in the case of the case, the radial protrusion 15g temporarily moves rearward along the slope 21a1 in the engagement hole 21a. 7, the clutch member 21 moves forward against the urging force of the compression coil spring 23, so that the wedges of the tapered inner peripheral surface 21 c of the clutch member 21 and the tapered outer peripheral surface 29 a of the eating roller 29 are provided. Power is reduced. Accordingly, transmission of the rotational force from the input rotary shaft 7 to the clutch member 21 is temporarily interrupted, and the output rotary shaft 15 does not rotate and only the input rotary shaft 7 rotates.
When the AF motor M continues to rotate and a predetermined time elapses, the clutch member 21 is returned to the initial position of FIG. 6 by the urging force of the compression coil spring 23. The groove 7c2 bites in between the end portion where the radial width of the groove 7c2 is narrow and the tapered inner peripheral surface 21c of the clutch member 21 with a strong force. As a result, the small diameter portion 7c (input rotation shaft 7) and the clutch member 21 are These are integrated in the circumferential direction via the biting roller 29, the retainer 25, and the differential bearing ball 27.

  In addition, the biting roller 29 bites into the small diameter portion 7c (input) between the end portion where the radial width of each unequal width groove 7c2 is narrow and the tapered inner peripheral surface 21c of the clutch member 21 with a strong force. After the rotation shaft 7) and the clutch member 21 are integrated in the circumferential direction, when a signal in the same direction as the rotation direction immediately before the biting roller 29 bites into the AF motor M from the control circuit, the small diameter portion 7c ( The input rotary shaft 7) and the clutch member 21 maintain the integral state in the circumferential direction, and the output rotary shaft 15 rotates.

Next, the operation of the lens barrel 100 when performing focusing by MF will be described.
When the manual focus ring 108 is rotated clockwise or counterclockwise in front view without driving the AF motor M, the moving ring 110 and the focus lens L2 move forward and backward to perform MF.
When the manual focus ring 108 is thus rotated, this rotational force is transmitted from the input gear 108c to the output gear 15d of the output rotary shaft 15, and the output rotary shaft 15 rotates clockwise or counterclockwise around the rotary shaft 5. To do. And according to the biting state with respect to each unequal width groove 7c2 of the biting roller 29 and the tapered inner peripheral surface 21c of the clutch member 21 at this time, the input rotary shaft 7 moves differently as follows.
When the biting roller 29 does not bite between the end portion where the radial width of each unequal width groove 7c2 is narrow and the tapered inner peripheral surface 21c of the clutch member 21, the diameter of the output rotating shaft 15 is reduced. The directional protrusion 15g and the engagement hole 21a of the clutch member 21 maintain the relationship shown in FIG. 6, but the rotational force of the clutch member 21 is not transmitted to the input rotary shaft 7 via the biting roller 29. Does not rotate, and the rotation shaft M1 of the AF motor M does not rotate.
On the other hand, when the biting roller 29 bites between the end portion where the radial width of each unequal width groove 7c2 is narrow and the tapered inner peripheral surface 21c of the clutch member 21 (for example, immediately after the AF operation) ), When the output rotation shaft 15 rotates, the relative rotational torque of the lens barrel 100 becomes larger than the predetermined torque. Then, as shown in FIG. 7, the urging force of the compression coil spring 23 is overcome, the radial protrusion 15g moves rearward along the inclined surface 21a1 in the engagement hole 21a, and the clutch member 21 is compressed. Since the spring 23 moves forward against the biasing force of the spring 23, the wedge force of the tapered inner peripheral surface 21c of the clutch member 21 and the tapered outer peripheral surface 29a of the biting roller 29 is reduced. For this reason, even if the clutch member 21 that receives the rotational force from the output rotary shaft 15 rotates, the biting roller 29 (and the retainer 25 and the differential bearing ball 27) uses the rotational force of the clutch member 21 as the input rotary shaft 7. Even if the manual focus ring 108 is rotated without being transmitted to, the rotation axis M1 of the AF motor M does not rotate.

  As described above, according to the lens barrel 100 of the present embodiment, AF can be performed by turning on the AF switch, and even if the manual focus ring 108 is rotated while the AF switch is on, Since this rotational force is not transmitted to the rotating shaft M1 of the AF motor M, the rotating shaft M1 does not become a rotational resistance for the manual focus ring 108. For this reason, it is possible to smoothly perform the MF operation without switching the AF switch to the OFF side.

  Further, when a rotational force is input to the input rotary shaft 7 to rotate the output rotary shaft 15 to focus the lens, the biting roller 29 firmly bites between the input rotary shaft 7 and the clutch member 21. When the manual focus ring 108 is rotated, the wedge force between the tapered inner peripheral surface 21 c of the clutch member 21 and the tapered outer peripheral surface 29 a of the biting roller 29 decreases, and the rotational force from the clutch member 21 to the biting roller 29 is reduced. Therefore, even after AF, the manual focus ring 108 interlocked with the clutch member 21 can be smoothly rotated.

  Further, the one-way input / output rotation transmission mechanism U1 rotates the differential bearing ball 27 while being delayed from the input rotation shaft 7, and the differential bearing ball 27 moves the biting roller 29 between the input rotation shaft 7 and the clutch member 21. Since the biting roller 29 functions as a rotational force transmitting member, torque can be reliably transmitted from the input rotating shaft 7 to the clutch member 21 (output rotating shaft 15). As a result, the AF operation can be performed reliably.

  Moreover, the biting roller 29, which is a rotational force transmitting member, has a conical shape with a head cut in a cross section orthogonal to the central axis C1, and therefore the input rotational shaft 7 as compared with the case where the rotational force transmitting member is spherical. And the contact area with the clutch member 21 is large. For this reason, the one-way input / output rotation transmission mechanism U1 has a higher transmission efficiency of rotational torque from the input rotation shaft 7 to the clutch member 21 (output rotation shaft 15) than when the rotational force transmission member is spherical.

  Instead of the differential bearing ball 27, a cylindrical differential roller (not shown) whose rotating shaft faces the radial direction of the input rotating shaft 7 is used so that the differential roller can freely rotate into the fitting hole 25c. The differential roller may be brought into contact with the axially orthogonal surface 7c1 and the pressing surface 17a. If it does in this way, the transmission efficiency of the rotational force from the input rotating shaft 7 to the retainer 25 will improve.

Furthermore, since each eating roller 29 is arrange | positioned in the annular space RS using the retainer 25, many eating rollers 29 can be arrange | positioned in the annular space RS. If the number of biting rollers 29 is increased in this way, the transmission efficiency of the rotational torque from the input rotary shaft 7 to the output rotary shaft 15 is improved.
If the reduction in rotational torque transmission efficiency is ignored, it is possible to dispose the biting roller 29 only in one storage space S1 or to implement the differential bearing ball 27 as one.

Next, a second embodiment of the present invention will be described with reference to FIGS. The same members as those in the first embodiment are designated by the same reference numerals, and detailed description thereof is omitted.
The second fixed ring 202 of the lens barrel 200 of the present embodiment has a rectilinear guide groove 202a similar to the second fixed ring 104 of the first embodiment, and the longitudinal length thereof is longer than that of the second fixed ring 104. The rear end is short and is fixed to the first fixed ring 102 by a fixing screw 106. Between the first fixed ring 102 and the second fixed ring 202, an annular arrangement space S is formed in a front view.
A rear end portion of the lens holding ring 204 that holds the fixed lens L 1 is fixed to the inner peripheral surface of the front end portion of the second fixed ring 202 by a fixing screw 206.

A manual focus ring (manual operation ring) 208 concentric with the first fixed ring 102 rotates around the optical axis O in an annular space formed between the front end portion of the first fixed ring 102 and the lens holding ring 204. It is arranged so as to be freely movable in the direction of the optical axis O. Further, in the arrangement space S, a distance adjusting ring 210 is arranged so as to be rotatable around the optical axis O and not movable in the direction of the optical axis O.
An input gear 210a that meshes with the output gear 15d of the one-way input / output rotation transmission mechanism U1 is formed on the entire inner peripheral surface of the rear end portion of the distance adjusting ring 210. The distance adjusting ring 210 is formed with a cam groove 210b into which the roller 114 is fitted, and the inner peripheral surface (rotation transmitting cylindrical surface) 210c at the front end of the distance adjusting ring 210 has a circular shape when viewed from the front.
A radially inward annular wall 208a protrudes from the inner peripheral surface of the manual focus ring 208. An annular ridge (annular overlapping portion) facing rearward is formed from the entire inner peripheral end of the annular wall 208a. ) 208b is extended.

As shown in FIG. 9, four storage recesses 212 are formed on the outer peripheral surface of the annular ridge 208b at equal angular intervals in the circumferential direction. The storage recess 212 includes a pair of unequal width grooves (second circumferential direction unequal width space forming portions) (second unequal width grooves) 214 and 214 whose depths vary depending on the circumferential position. And a flat portion (second circumferentially unequal width space forming portion) 216 formed between the equal width grooves 214, and the front surface thereof is orthogonal to the optical axis O as shown in FIG. It is an axially orthogonal surface (second axially orthogonal surface) 212a. A storage space (second circumferential unequal width space) SS having a different shape depending on the circumferential position is formed between each unequal width groove 214 and the flat portion 216 and the inner circumferential surface 210c of the distance adjusting ring 210. Is formed.
As shown in FIGS. 9 to 12, between the flat portion 216 and the inner peripheral surface 210 c of the distance adjusting ring 210, the center axis (rotating axis) CA <b> 1 has a substantially cylindrical shape facing the radial direction of the manual focus ring 208. A differential roller (second differential rotating member) 218 is provided. As shown in FIG. 10, an annular member (second pressing member) 220 having an annular shape in front view is formed in an annular space formed between the front end surface of the second fixed ring 202 and the annular protrusion 208b. And an annular leaf spring (third biasing means) 222 provided between the annular member 220 and the front end surface of the second fixed ring 202 in a front view. Due to the urging force of the leaf spring 222, the pressing surface (second pressing surface) 220a parallel to the axially orthogonal surface 212a of the annular member 220 is always in contact with the rear surface of each differential roller 218. The front of each differential roller 218 is always in contact with the axially orthogonal surface 212a of the housing recess 212.

  Furthermore, each storage recess 212 (storage space SS) has a pair of eating rollers (substantially cylindrical shapes) whose center axis (rotation axis) CA2 faces the direction parallel to the optical axis O so that the differential rollers 218 are sandwiched between them. A second rotational force transmission member) 224 is disposed. The outer peripheral surface of each eating roller 224 is in contact with each unequal width groove 214 and the inner peripheral surface 210c of the distance adjusting ring 210 so as to be freely rotatable.

As shown in FIG. 8, an annular holding member 226 is rotatable around the optical axis O in a space formed between the lens holding ring 204 and the annular wall 208a of the manual focus ring 208 and having an annular shape when viewed from the front. It is arranged. The annular holding member 226 is provided with a plurality of holding holes 226a arranged in the circumferential direction, and bearing balls 228 are rotatably held in the holding holes 226a, and each bearing ball 228 is attached to the annular wall 208a. And the lens holding ring 204 are rotatably contacted.
Then, the annular protrusion 208b of the manual focus ring 208, the inner peripheral surface 210c of the distance adjusting ring 210, the housing recess 212 (the axial orthogonal surface 212a, the unequal width groove 214, the flat portion 216), the differential roller 218, the annular member The one-way input / output rotation transmission mechanism (second one-way input / output rotation transmission mechanism) U2 is configured by 220, the leaf spring 222, and the eating roller 224.
Further, although not shown, the lens barrel 200 is provided with an AF switch that enables or disables AF shooting.

Next, the operation of the lens barrel 200 configured as described above will be described.
First, the operation of the lens barrel 200 when performing focusing by AF will be described. The one-way input / output rotation transmission mechanism U1 operates in the same manner as in the first embodiment.

First, the AF switch is turned on so that AF shooting is possible. The state where the biting roller 29 does not bite with a strong force between the end portion where the radial width of each unequal width groove 7c2 is narrow and the tapered inner peripheral surface 21c of the clutch member 21 (the biting roller 29 Is located at the center (the deeply recessed portion) of the unequal width groove 7c2), a control circuit (not shown) provided in the camera body sends a forward rotation signal to the AF motor M, and AF When the motor M rotates forward, the rotational force of the AF motor M is transmitted to the input rotary shaft 7 via the pinion P and the input gear 7g. Then, the output rotating shaft 15 rotates counterclockwise, the rotational force of the output rotating shaft 15 is transmitted from the output gear 15d to the input gear 210a, and the distance adjusting ring 210 rotates counterclockwise when viewed from the front, and the focus lens L2 moves forward along the optical axis O.
Even if the distance adjusting ring 210 rotates in this way, the inner peripheral surface 210c of the front end portion of the distance adjusting ring 210 is circular in front view, so that the rotational force is applied from the distance adjusting ring 210 to the differential roller 218. As shown in FIG. 11, the biting roller 224 does not move in the circumferential direction. For this reason, the manual focus ring 208 does not rotate.

On the other hand, when a reverse signal is sent from the control circuit to the AF motor M to reverse the AF motor M, the rotational force is transmitted to the input rotary shaft 7 via the pinion P, and as in the first embodiment, The output rotation shaft 15 rotates clockwise. When the output rotating shaft 15 rotates, the rotational force of the output rotating shaft 15 is transmitted from the output gear 15d to the input gear 210a, the distance adjusting ring 210 rotates clockwise in front view, and the focus lens L2 follows the optical axis O. To move backwards.
Also in this case, even if the distance adjusting ring 210 rotates, no rotational force is transmitted from the distance adjusting ring 210 to the differential roller 218, and the biting roller 224 does not move in the circumferential direction, so the manual focus ring 208 rotates. do not do.
Thus, AF is performed by the control circuit rotating the AF motor M in both forward and reverse directions and moving the focus lens L2 back and forth.

As will be described later, the biting roller 224 of the one-way input / output rotation transmission mechanism U2 has an unequal width groove 214 and an inner portion of the distance adjustment ring 210 at the end where the radial width of each storage space SS is narrow. When the distance adjusting ring 210 rotates in the same direction as that immediately before it bites into the peripheral surface 210c with a strong force, the manual focus ring 208 rotates together with the distance adjusting ring 210.
Further, as will be described later, even if the eating roller 224 bites between the unequal width groove 214 and the inner peripheral surface 210 c of the distance adjusting ring 210, the eating roller 224 has a sectional diameter of the eating roller 29. Since it is larger than the diameter, when the hand is released from the manual focus ring 208, the manual focus ring 208 automatically rotates slightly in the direction to release the bite, and the bite is automatically released.

Next, the operation of the lens barrel 200 when focusing by MF will be described.
The biting roller 29 of the one-way input / output rotation transmission mechanism U1 has a strong force between the end of each unequal width groove 7c2 where the radial width is narrow and the tapered inner peripheral surface 21c of the clutch member 21. When the manual focus ring 208 is rotated counterclockwise in a front view without driving the AF motor M with the AF switch held in the ON state without being bitten, the pressing surface 220a of the annular member 220 is Each differential roller 218 sandwiched between the axial orthogonal surfaces 212a rotates around the central axis CA1 in the respective storage recesses 212 in the same direction (counterclockwise) as the manual focus ring 208 around the optical axis O. Revolve (rotate). At this time, if no slip occurs between each differential roller 218 and the pressing surface 220a and the axially orthogonal surface 212a, the rotational speed of each differential roller 218 is ½ of the manual focus ring 208. As a result, as shown in FIG. 12, each differential roller 218 rotates relative to the manual focus ring 208 in the clockwise direction in front view. For this reason, each differential roller 218 comes into contact with the biting roller 224 positioned in the clockwise direction when viewed from the front, and applies a clockwise rotational force to the biting roller 224. The eating roller 224 to which the rotational force is applied rotates clockwise in each storage space SS, and the unequal width groove 214 is formed at the end portion on the clockwise side where the radial width of each storage space SS is narrow. And the inner peripheral surface 210c of the distance adjusting ring 210 are bitten with a strong force. As a result, the manual focus ring 208 and the distance adjustment ring 210 are integrated in the circumferential direction via the eating roller 224, so that the rotational force of the manual focus ring 208 is transmitted to the distance adjustment ring 210, and the distance adjustment ring 210 is counterclockwise. Rotate in the direction. When the distance adjustment ring 210 rotates counterclockwise, the focus lens L2 moves forward along the optical axis O.

When the distance adjusting ring 210 rotates in this way, this rotational force is transmitted to the output gear 15d of the one-way input / output rotation transmission mechanism U1 via the input gear 210a. However, as in the first embodiment, the one-way Since the input / output rotation transmission mechanism U1 does not transmit this rotational force to the AF motor M, the rotation shaft M1 of the AF motor M does not rotate.
Furthermore, since the cross-sectional diameter of the bite roller 224 is larger than the cross-sectional diameter of the bite roller 29, the bite roller 224 is rotated by operating the manual focus ring 208 so that the bite roller 224 becomes the inner circumference of the unequal width groove 214 and the distance adjustment ring 210. Even if it bites into the surface 210c, when the hand is released from the manual focus ring 208, the manual focus ring 208 automatically rotates slightly clockwise in front view, and this bite state is automatically released.

On the other hand, when the manual focus ring 208 is rotated clockwise in a front view, each differential roller 218 held between the pressing surface 220a of the annular member 220 and the axially orthogonal surface 212a is centered in each storage recess 212. While rotating around the axis CA1, it revolves (rotates) around the optical axis O in the same direction (clockwise) as the manual focus ring 208. At this time, if no slip occurs between each differential roller 218 and the pressing surface 220a and the axially orthogonal surface 212a, the rotational speed of each differential roller 218 is ½ of the manual focus ring 208. As a result, each differential roller 218 rotates relative to the manual focus ring 208 counterclockwise in front view. For this reason, each differential roller 218 comes into contact with the biting roller 224 located on the counterclockwise side when viewed from the front, and applies a counterclockwise rotational force to the biting roller 224. The eating roller 224 given the rotational force rotates counterclockwise in each storage space SS, and has an unequal width at the counterclockwise end where the radial width of each storage space SS is narrow. It bites in with a strong force between the groove 214 and the inner peripheral surface 210c of the distance adjusting ring 210. As a result, the manual focus ring 208 and the distance adjustment ring 210 are integrated in the circumferential direction via the eating roller 224, and the distance adjustment ring 210 rotates in the clockwise direction. When the distance adjusting ring 210 rotates in the clockwise direction, the focus lens L2 moves rearward along the optical axis O.

When the distance adjusting ring 210 rotates in this way, this rotational force is transmitted to the output gear 15d of the one-way input / output rotation transmission mechanism U1 via the input gear 210a. In this case as well, the one-way input / output rotation transmission mechanism U1. Does not transmit this rotational force to the AF motor M, and the rotating shaft M1 does not rotate.
Further, as described above, even if the manual focus ring 208 is rotated and the biting roller 224 bites between the unequal width groove 214 and the inner peripheral surface 210c of the distance adjusting ring 210, the hand is moved from the manual focus ring 208. When released, the manual focus ring 208 automatically rotates slightly counterclockwise in front view, so that the state of biting into the unequal width groove 214 of the biting roller 224 and the inner peripheral surface 210c of the distance adjusting ring 210 is automatically Is released.

  According to the lens barrel 200 of the present embodiment described above, not only the same effects as in the first embodiment are obtained, but also the manual focus ring 208 does not rotate during the AF operation, so that the photographer's hand can be manually operated. An effect that the AF operation can be performed smoothly even when the focus ring 208 is touched is not obtained in the first embodiment.

It should be noted that the first and second embodiments can be modified as follows.
For example, the wedge angle of the wedge-shaped storage space S1 formed by the end of the unequal width groove 7c2 and the clutch member 21, the strength of the compression coil spring 19, the axial orthogonal surface 7c1 and the pressing surface 17a of the annular member 17 By changing the surface roughness, it is possible to change the transmission efficiency of the rotational torque from the input rotary shaft 7 to the output rotary shaft 15.
Furthermore, the clutch member 21 may be provided with a radial protrusion, and the output rotation shaft 15 may be provided with an engagement hole.

  Further, in the unidirectional input / output rotation transmission mechanism U2 of the second embodiment, the annular protrusion 208b of the manual focus ring 208 is positioned on the outer peripheral side of the front end portion of the distance adjusting ring 210, and the inner peripheral surface of the annular protrusion 208b. Is formed in the storage recess 212, and the outer peripheral surface of the front end portion of the distance adjusting ring 210 is a circular rotation transmission cylindrical surface that is circular in front view, and the rotation transmission is performed with the non-uniform width groove 214 and the flat portion 216 formed in the storage recess 212. A second circumferential unequal width space may be formed between the cylindrical surfaces, and the differential rollers 218 and the eating rollers 224 may be disposed between the storage recess and the rotation transmission cylindrical surface.

In the first and second embodiments, the one-way input / output rotation transmission mechanism U1 is applied to the focus lens barrel, but may be applied to a zoom lens barrel. That is, the power zoom is performed by the distance adjusting ring for moving the lens barrel 100, 200 in the optical axis direction of the moving ring holding the zoom lens, and the zoom ring (manual operation ring) when the power zoom switch is OFF. When the switch is ON, it is configured to be rotated by a zoom motor (motor) that is driven in conjunction with the rotation of the zoom ring, and one-way input / output rotation is transmitted between the zoom motor and the distance adjustment ring. A mechanism U1 is provided.
If the lens barrels 100 and 200 are configured as described above, if the zoom ring is rotated after turning on the power zoom switch, the distance adjusting ring is rotated by the driving force of the zoom motor to perform zooming. . On the other hand, manual zooming is performed by turning the zoom ring with the power zoom switch turned OFF. At this time, the one-way input / output rotation transmission mechanism U1 applies the rotational force of the distance adjustment ring rotated by the zoom ring. Since it is not transmitted to the zoom motor, the manual zoom operation can be smoothly performed without receiving resistance from the zoom motor.

It is a vertical side view of the upper half part of the lens barrel of the first embodiment of the present invention. It is a vertical side view of the 1st one way input / output rotation transmission mechanism. FIG. 3 is a longitudinal front view in which a housing, an output rotation shaft, an AF motor, an input gear of an input rotation shaft, and a compression coil spring are omitted along line III-III in FIG. 2. FIG. 4 is a longitudinal front view of the housing, the output rotation shaft, the AF motor, the input gear of the input rotation shaft, and the compression coil spring, taken along line IV-IV in FIG. 2. It is the elements on larger scale of the outer peripheral surface of a retainer. It is a side view which shows the positional relationship of an output rotating shaft and a clutch member when rotational force is input into the input rotating shaft. It is a side view which shows the positional relationship of an output rotating shaft and a clutch member when rotational force is input into the output rotating shaft. It is a vertical side view of the upper half part of the lens barrel of the second embodiment of the present invention. FIG. 9 is an enlarged longitudinal sectional front view taken along line IX-IX in FIG. 8 omitting a lens holding ring, a moving ring, and a focus lens. It is the enlarged view which looked at the 2nd one-way input / output rotation transmission mechanism from the outer peripheral side of the annular ridge. It is an enlarged vertical front view of a second one-way input / output rotation transmission mechanism. It is an enlarged vertical front view of the second one-way input / output rotation transmission mechanism when the manual focus ring is rotated.

Explanation of symbols

3 housing 3a annular flange 3b front wall 3c circular plate 3d window hole 5 rotation shaft 5a small diameter portion 5b large diameter portion 7 input rotation shaft 7a central hole 7b housing recess 7c small diameter portion 7c1 axial direction orthogonal surface (first axial direction orthogonal surface )
7c2 Circumferential unequal width groove (first circumferential unequal width space forming portion) (first unequal width groove)
7d Rear wall 7e Outer peripheral wall 7f Annular step 7g Input gear 7h Annular recess 9 Bearing ball 11 Retaining plate 13 Fixing screw 15 Output rotating shaft 15a Small diameter cylindrical part 15b Large diameter cylindrical part 15c Center hole 15d Output gear 15e Annular Ridge 15f annular flange 15g radial projection (power transmission pin) (linking means)
17 annular member (first pressing member)
17a Press surface 19 Compression coil spring (first biasing means)
21 clutch member 21a engagement hole (power transmission hole) (linkage means)
21a1 Inclined surface 21b Annular flange 21c Tapered inner peripheral surface (inner peripheral contact surface) (first tapered surface)
23 Compression coil spring (second biasing means)
25 Retainer 25a Front wall 25b Insertion hole 25c Fitting hole 25d Cylindrical portion 25e Mounting hole 27 Differential bearing ball (first differential rotating member)
29 Eating roller (first rotational force transmission member)
29a Tapered outer peripheral surface (contact surface with circular cross section) (second tapered surface)
100 Lens barrel 102 First fixed ring 102a Bayonet portion 104 Second fixed ring 104a Straight guide groove 104b Front end portion 106 Fixing screw 108 Manual focus ring (manual operation ring)
108a Rotating operation portion 108b Cam groove 108c Input gear 110 Moving ring 110a Radial protrusion 112 Mounting screw 114 Roller 200 Lens barrel 202 Second fixed ring 202a Straight guide groove 204 Lens holding ring 206 Fixed screw 208 Manual focus ring (manual operation) ring)
208a Annular wall 208b Annular ridge (annular overlapping portion) (second one-way input / output rotation transmission mechanism)
210 Distance adjusting ring 210a Input gear 210b Cam groove 210c Inner circumferential surface (rotation transmission cylindrical surface) (second one-way input / output rotation transmission mechanism)
212 Storage recess (second one-way input / output rotation transmission mechanism)
212a Axial orthogonal plane (second axial orthogonal plane) (second one-way input / output rotation transmission mechanism)
214 Non-uniform width groove (second circumferential direction non-uniform width space forming portion) (second non-uniform width groove) (second one-way input / output rotation transmission mechanism)
216 flat part (second circumferentially unequal width space forming part)
218 Differential roller (second differential rotation member) (second one-way input / output rotation transmission mechanism)
220 annular member (second pressing member) (second one-way input / output rotation transmission mechanism)
220a pressing surface (second pressing surface)
222 Leaf spring (third biasing means) (second one-way input / output rotation transmission mechanism)
224 Eating roller (second rotational force transmission member) (second one-way input / output rotation transmission mechanism)
226 annular holding member 228 bearing ball C1 CA1 CA2 central axis (rotating axis)
CS annular storage space L1 fixed lens L2 focus lens (moving lens)
M AF motor (motor)
M1 Rotating shaft P Pinion RS Annular space S Arrangement space S1 Storage space (first circumferentially unequal width space)
SS storage space (second circumferential non-uniform width space)
U1 one-way input / output rotation transmission mechanism (first one-way input / output rotation transmission mechanism)
U2 one-way input / output rotation transmission mechanism (second one-way input / output rotation transmission mechanism)

Claims (22)

A manual operation ring that moves the moving lens in the optical axis direction by manual rotation operation;
A motor for driving the moving lens in the optical axis direction;
A first one-way input / output rotation transmission mechanism that transmits the driving force to the moving lens when the motor is driven and does not transmit the moving force of the moving lens to the motor when the manual operation ring is rotated. When,
In a lens barrel comprising:
The first one-way input / output rotation transmission mechanism is
An input rotary shaft having a first axially orthogonal plane orthogonal to an axis parallel to the optical axis and driven to rotate by the motor;
An output rotation shaft that is rotatable relative to the input rotation shaft about the axis, and whose rotational movement and movement of the movable lens in the optical axis direction are linked;
A cylindrical clutch member that is concentric with the input rotation shaft and located on the outer peripheral side thereof, is relatively movable in the axial direction with respect to the output rotation shaft, and has an inner peripheral surface as an inner peripheral contact surface;
Located on a circumference centered on the axis of the input rotation shaft, is always brought into contact with the first axially orthogonal plane by the first biasing means, and interlocked with the rotation of the input rotation shaft A first differential rotating member that revolves in the same direction while being delayed from the input rotating shaft around the axis of the input rotating shaft;
A first circumferential unequal width space that is formed on the outer circumferential surface of the input rotation shaft and forms a first circumferential unequal width space that is circumferentially unequal in width with the inner circumferential surface of the clutch member. Forming part;
An inner circumference of the clutch member that is movably inserted into the first circumferentially unequal width space and revolves in the same direction as the first differential rotating member in conjunction with the first differential rotating member. A first rotational force transmission member having a circular contact surface in cross section capable of contacting the contact surface;
Normally, the clutch member is urged in a direction to increase the frictional force between the inner peripheral contact surface of the clutch member and the circular contact surface of the first rotational force transmitting member, and the clutch member outputs the output. Second urging means for preventing relative movement with respect to the rotation axis;
Linkage means for transmitting the rotational force generated in one of the clutch member or the output rotary shaft to the other, and
The first circumferential unequal width space forming portion rotates in the circumferential direction in conjunction with the input rotation shaft and the first differential rotation member when a rotational force is input to the input rotation shaft. The first rotational force transmitting member is caused to bite between the first circumferential unequal width space forming portion and the clutch member while the circular contact surface of the cross section is in contact with the inner peripheral contact surface. The input rotating shaft and the clutch member are integrated in the circumferential direction,
When the rotational force is input to the input rotation shaft, the linkage means transmits the rotational force from the clutch member integrated with the input rotation shaft to the output rotation shaft, and the output rotation shaft. When a relative rotational torque, which is the difference between the rotational torque of the output rotational shaft and the rotational torque of the input rotational shaft, is greater than a predetermined torque determined by the shape of the linkage means, The clutch member is moved relative to the output rotation shaft in a direction to reduce the frictional force against the urging force of the urging means, and the clutch member and the rotational force transmitting member are integrated in the circumferential direction. A lens barrel that releases the state. The lens barrel according to claim 1,
The linking means regulates the relative movement of the clutch member with respect to the output rotation shaft when the rotational force is input to the input rotation shaft and the relative rotation torque is equal to or less than the predetermined torque, and the relative rotation is performed. When the torque becomes larger than the predetermined torque, the clutch member is temporarily allowed to move relative to the output rotation shaft, and then the clutch member is urged by the urging force of the second urging means. Is a lens barrel that allows the lens to return to the initial position and keeps this state thereafter. The lens barrel according to claim 1 or 2,
In the link means, when the first rotational force transmission member does not bite between the first circumferentially unequal width space forming portion and the clutch member, rotational force is input to the output rotation shaft. And a lens barrel that does not move the clutch member relative to the output rotation shaft. In the lens barrel according to any one of claims 1 to 3,
An annular space having the first circumferential unequal width space is formed between the input rotation shaft and the clutch member,
An annular retainer that receives the rotational force of the first differential rotating member and rotates in the same direction as the first differential rotating member is inserted into the annular space,
A lens barrel in which the retainer holds the first rotational force transmission member. In the lens barrel according to any one of claims 1 to 4,
A first pressing surface facing and parallel to the first axially orthogonal surface, and always urged toward the first axially orthogonal surface by the first urging means; Comprising a pressing member;
A lens barrel in which the first differential rotation member is always held between the first pressing surface and the first axially orthogonal surface. In the lens barrel according to any one of claims 1 to 5,
A lens barrel in which the linkage means includes a power transmission pin formed on one of the clutch member and the output rotation shaft, and a power transmission hole in which the power transmission pin formed on the other is loosely fitted. The lens barrel according to claim 6, wherein
A lens barrel in which the predetermined torque is determined by the shape of the power transmission hole and the power transmission pin. In the lens barrel according to any one of claims 1 to 7,
A lens barrel in which the inner peripheral contact surface is a first tapered surface, and the circular cross-sectional contact surface is a second tapered surface inclined in substantially the same direction as the first tapered surface. The lens barrel according to claim 8, wherein
A lens barrel in which the first rotational force transmission member is a conical member having a cut head. The lens barrel according to any one of claims 1 to 9,
A lens barrel in which the first differential rotation member is a differential roller having a substantially cylindrical shape whose rotation axis faces the radial direction of the input rotation axis. The lens barrel according to any one of claims 1 to 10,
A lens barrel in which the first differential rotating member is a spherical differential bearing ball. The lens barrel according to any one of claims 1 to 11,
The first circumferential unequal width space forming portion forms a plurality of the first circumferential unequal width spaces between the inner circumferential contact surface of the clutch member,
A lens barrel in which the first rotational force transmitting member is inserted into each first circumferentially unequal width space. The lens barrel according to any one of claims 1 to 12,
A lens barrel in which the first circumferentially unequal width space forming portion is a first unequal width groove having a radial depth that varies depending on a circumferential position. The lens barrel according to any one of claims 1 to 13,
A distance adjusting ring that rotates around the axis of the rotating shaft by receiving a rotating force from the manual operation ring or receiving a rotating force from the output rotating shaft, and moves the moving lens in the optical axis direction;
Between the distance adjustment ring and the manual operation ring, the rotational force of the manual operation ring is transmitted to the distance adjustment ring, but the rotational force of the distance adjustment ring is not transmitted to the manual operation ring. Lens barrel with input / output rotation transmission mechanism. The lens barrel according to claim 14, wherein
The second one-way input / output rotation transmission mechanism is
A second axially orthogonal surface orthogonal to the optical axis, and a circular polymerization portion that is polymerized in the radial direction with the distance adjusting ring, provided in the manual operation ring;
A rotation transmitting cylindrical surface that is formed on an inner peripheral surface or an outer peripheral surface of the distance adjusting ring and that faces the annular overlapping portion of the manually operated ring;
A second circumferentially unequal width space that forms a second circumferentially unequal width space having an unequal width in the circumferential direction between the rotation transmitting cylindrical surface formed in the annular overlap portion of the manually operated ring. Forming part;
It is inserted into the second circumferential unequal width space, and is always brought into contact with the second axially orthogonal plane by the third biasing means, and in conjunction with the rotation of the manual operation ring, A second differential rotation member that revolves in the circumferential direction unequal width space forming portion around the axis of the manual operation ring in the same direction while being delayed from the manual operation ring;
A second rotational force transmitting member inserted into the second circumferentially unequal width space and revolved in the same direction as the second differential rotating member by being pushed by the second differential rotating member; With
The second circumferential direction unequal width space forming portion is configured such that the second rotational force transmitting member rotated in the circumferential direction is between the second circumferential direction unequal width space forming portion and the rotation transmitting cylindrical surface. A lens barrel having a shape that bites in and transmits the rotational force of the manual operation ring to the distance adjustment ring. The lens barrel according to claim 15,
A lens barrel in which a pair of the second rotational force transmitting members are inserted side by side in the circumferential direction so as to sandwich the second differential rotating member in the second circumferentially unequal width space. The lens barrel according to claim 15 or 16,
A lens barrel in which at least a part of the second circumferentially unequal width space forming portion is constituted by a second unequal width groove having a radial depth that varies depending on a circumferential position. The lens barrel according to any one of claims 15 to 17,
The second pressing surface is opposite to and parallel to the second axially orthogonal surface, and is always urged toward the second axially orthogonal surface by the third urging means, A lens barrel comprising a second pressing member that sandwiches the second differential rotating member between two axially orthogonal surfaces. The lens barrel according to any one of claims 15 to 18,
The second circumferential unequal width space forming part forms a plurality of the second circumferential unequal width spaces between the rotation transmitting cylindrical surface of the distance adjusting ring,
A lens barrel in which the second differential rotating member and the second rotational force transmitting member are inserted into each second circumferentially unequal width space. The lens barrel according to any one of claims 15 to 19,
A lens barrel in which the second rotational force transmitting member is a columnar member facing a direction parallel to the axis of the manual operation ring. The lens barrel according to any one of claims 1 to 20,
The moving lens is a focus lens,
The motor is an AF motor,
A lens barrel in which the manual operation ring is a manual focus ring. The lens barrel according to any one of claims 1 to 20,
The moving lens is a zoom lens,
The motor is a zoom motor,
A lens barrel in which the manual operation ring is a zoom ring.

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