JP2013210481A - Photographing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To optimally set whether priority is given to the prevention of the occurrence of vignetting or priority is given to the speed of separation drive, according to a use state and the taste of a user, when a rotary optical element such as a polarizing filter is driven to be separated from an insertion position to a separation position.SOLUTION: An imaging apparatus includes the rotary optical element rotated around the optical axis of a photographic optical system on the optical path of the photographic optical system, an insertion/removal drive mechanism performing the insertion and removal drive of the rotary optical element between the insertion position onto the optical path of the photographic optical system and the separation position from the optical path of the photographic optical path, an input part inputting a separation drive instruction signal for performing the separation drive of the rotary optical element from the insertion position to the separation position, a separation drive mode setting part setting a vignetting prevention priority separation drive mode or a speed priority separation drive mode, and a control part controlling the separation drive of the rotary optical element by the insertion/removal drive mechanism, in a different aspect, according to the separation drive mode set by the separation drive mode setting part, when the input part inputs the separation drive instruction signal.

Description

  The present invention relates to a photographing apparatus provided with a rotating optical element (for example, a polarizing filter) so as to be freely inserted into and removed from an optical path of a photographing optical system.

  Conventionally, as a photographing device such as a digital camera, a device equipped with a polarizing filter (rotating optical element) that is detachably provided in the optical path of the photographing optical system and changes the polarization state by rotating around the optical axis in the inserted state. Is known (Patent Documents 1 and 2). In this type of photographing apparatus, when the polarizing filter is driven to be detached from the insertion position to the separation position, the filter frame (holding member) that holds the polarizing filter is defined by the effective light beam of the photographing optical system (the variable aperture of the variable aperture stop). Vignetting may occur and the user's feeling of use may be impaired. On the other hand, depending on the use situation and user preference, there is a case where it is desired to drive the polarizing filter as soon as possible without considering the occurrence of vignetting as a problem.

JP 2006-337695 A JP-A-3-192231

  The present invention has been completed on the basis of the above-mentioned problem awareness, and when a rotary optical element such as a polarizing filter is driven to be detached from the insertion position to the separation position, vignetting occurs depending on the use situation and the user's preference. An object of the present invention is to obtain an imaging apparatus capable of optimally setting whether to give priority to prevention of image pickup or to give priority to the speed of disengagement drive.

  The photographing apparatus of the present invention includes a rotating optical element that rotates about the optical axis of the photographing optical system on the optical path of the photographing optical system; the rotating optical element is on the same optical path as the insertion position of the photographing optical system on the optical path. An insertion / removal drive mechanism for driving to / from the separation position; an input unit for inputting a separation drive instruction signal for driving the rotation optical element to the separation position from the insertion position; And a separation drive mode setting unit that sets one of the speed priority separation drive modes; and when the input unit inputs a separation drive instruction signal, the insertion drive mode setting unit sets the insertion according to the separation drive mode set by the separation drive mode setting unit. A controller that controls the detachment drive of the rotating optical element by a detachment mechanism in a different manner.

  The insertion / removal drive mechanism includes: a support member; a drive rotation member that is rotatably supported by the support member in a direction around the optical axis of the photographing optical system and is driven to rotate in the rotation direction by a drive source; A driven rotating member supported by the member so as to be rotatable in a direction around the optical axis and capable of rotating relative to the driving rotating member in the rotating direction; resistance applying means for applying rotational resistance to the driven rotating member; A rotation transmitting portion that holds the rotating optical element and transmits a force in the rotational direction from the driving rotating member; and a shaft supporting portion with respect to the driven rotating member; A holding member for rotating and inserting the rotating optical element on the optical path; an insertion control means for restricting the rotation of the holding member at an insertion position on the optical path; and the optical axis with respect to the holding member. Times Detachment control that allows movement to a fully detached position from the optical path at a specific position in the direction and restricts rotation at a restricted leaving position that is smaller than the specific position in the rotational direction and has a smaller movement amount in the separating direction than the completely detached position. And the insertion / removal drive mechanism is rotated by the resistance applying unit by rotating the driving rotation member in a direction in which the holding member is not subjected to rotation restriction by the insertion control unit and the separation control unit. A differential rotation operation in which a differential in the rotation direction is generated between the driven rotation member that receives resistance and the driving rotation member, and the holding member rotates in an insertion / removal direction around the shaft support portion; When the holding member is in the insertion position, the rotation member by the resistance applying unit rotates the driving rotation member in a direction in which the holding member receives the rotation restriction by the insertion control unit. The driven rotation member and the holding member rotate together with the driving rotation member around the optical axis; and the holding member is in the limit release position when the holding member is in the limit release position. By rotating the driving rotation member in a direction to receive the rotation restriction by the separation control unit, the driven rotation member and the holding member rotate together with the driving rotation member against the rotation resistance by the resistance applying unit, A follow-up reverse rotation operation in which the holding member is rotated to the complete disengagement position at a specific position in the rotation direction can be performed.

The limited disengagement position includes a position immediately before disengagement in which the retaining member shifts from the restrictive disengagement position to the complete disengagement position when the retaining member is rotated by a predetermined amount by the follow-up reverse rotation operation. When the input unit inputs a separation drive instruction signal and the separation drive mode setting unit is setting the vignetting prevention priority separation drive mode, the unit inserts the following insertion / removal drive mechanism into the following (1) to The operation step (3) can be executed.
(1) An operation step of performing the revolving positive rotation operation while the holding member is kept in the insertion position until the holding member reaches a rotation angle position corresponding to the position immediately before the separation.
(2) An operation step of causing the holding member to shift from the insertion position to the position immediately before the separation by performing the differential rotation operation after the holding member has reached a rotation angle position corresponding to the position immediately before the separation.
(3) An operation step in which the holding member is moved from the position immediately before the separation to the complete separation position by performing the reverse rotation operation after the holding member is moved to the position immediately before the separation.

The insertion / removal drive mechanism further includes a detection unit that detects a rotation angle position of the rotating optical element at a time point when the input unit inputs a separation drive instruction signal, and the limit separation position is the counter-rotating reverse rotation. When the holding member is rotated by a predetermined amount by the operation, the holding member includes a position immediately before separation where the holding member shifts from the limited separation position to the complete separation position. When the separation drive mode setting unit sets the speed priority separation drive mode, the insertion / removal drive mechanism can execute the following operation steps (1) and (2). .
(1) Based on the detection result of the detection unit, after the holding member is shifted from the insertion position to the restricted release position by the differential rotation operation, the holding member is immediately before the release by the follow reverse rotation operation. The holding member is positioned at the position immediately before the separation by the differential rotation operation after the holding member has reached the rotation angle position corresponding to the position immediately before the separation by the forward rotating rotation operation. An operation step of performing the operation of which the time required is shorter, and positioning the holding member at the position immediately before the separation.
(2) An operation step of moving the holding member from the position immediately before separation to the complete separation position by performing the reverse rotation operation after the holding member is positioned at the position immediately before separation.

  The position immediately before the separation is shifted from the restricted separation position to the complete separation position when the holding member is rotated by α ° (however, 0 ° <α ° <180 °) by the reverse rotation operation. It can be a position to do.

  The input unit includes a rotary optical element separation switch for driving the rotation optical element to be detached, and a power switch for switching the power of the photographing apparatus from on to off, and the separation drive mode setting unit includes the The vignetting prevention priority separation drive mode can be set when the rotary optical element separation switch inputs the separation drive instruction signal, and the speed priority separation drive mode can be set when the power switch inputs the separation drive instruction signal.

  Alternatively, the separation drive mode setting unit may use a separation drive mode changeover switch that switches between a vignetting prevention priority separation drive mode and a speed priority separation drive mode as the separation drive mode setting unit.

  The rotating optical element may be a polarizing filter.

  According to the imaging apparatus of the present invention, when driving a rotating optical element such as a polarizing filter from the insertion position to the separation position, priority is given to prevention of vignetting or separation depending on the use situation and user preference. An imaging apparatus capable of optimally setting whether to prioritize the driving speed is obtained.

It is sectional drawing in the imaging | photography state (zoom area) which shows one Embodiment of the zoom lens barrel which mounts the imaging device by this invention. It is sectional drawing in the accommodation (collapse) state of the zoom lens barrel. It is a perspective view of the 2 group lens block which comprises the zoom lens barrel. It is a disassembled perspective view of a 2 group lens block. It is a disassembled perspective view of the polarizing filter unit contained in a 2 group lens block. FIG. 6 is a front view of the polarization filter unit in a state in which the polarization filter is detached, viewed from the front in the optical axis direction with the motor support member omitted. FIG. 6 is a rear view of the polarizing filter unit in a state in which the polarizing filter is detached, as viewed from the rear in the optical axis direction with the base member omitted. It is sectional drawing which follows the VIII-VIII line of FIG. FIG. 5 is a front view of the polarizing filter unit in a state in which the polarizing filter is inserted as viewed from the front in the optical axis direction with the motor support member omitted. It is the rear view which looked at the polarizing filter unit in the state of inserting a polarizing filter from the back in the optical axis direction with the base member omitted. It is sectional drawing which follows the XI-XI line of FIG. It is sectional drawing which follows the XII-XII line | wire of FIG. It is sectional drawing which follows the XIII-XIII line | wire of FIG. It is sectional drawing which follows the XIV-XIV line | wire of FIG. It is the front view which showed the operation | movement which makes a polarizing filter change from an detachment | leave state to an insertion state, and also rotates the polarization filter of an insertion state to an optical axis center in order of (A). It is the rear view which showed the operation | movement which makes a polarizing filter change from an detaching state to an insertion state, and also rotates the polarizing filter of an insertion state to an optical axis center in order of (A). It is the front view which showed the operation | movement which changes a polarizing filter from an insertion state to a removal state in order of (A) to (F). FIG. 3 is a block diagram conceptually showing a part of electric parts of a camera on which the zoom lens barrel of FIGS. 1 and 2 is mounted. It is a figure for demonstrating the position immediately before detachment | leave of a filter frame. It is the front view which showed the separation drive operation | movement of the polarizing filter in the vignetting prevention priority separation drive mode in order of (A) to (E). It is a conceptual diagram which shows the separation drive operation | movement of the polarizing filter in speed priority separation drive mode. It is a flowchart which shows the control content by the control circuit at the time of the separation drive of a polarizing filter.

  1 and 2 show an embodiment of a retractable zoom lens barrel ZL to which the present invention is applied. The imaging optical system of the zoom lens barrel ZL includes a first lens group LG1, a shutter S, a second lens group LG2, a third lens group LG3, a low-pass filter 25, and an imaging element 26 in order from the object (subject) side. Yes. In addition, a polarizing filter (rotating optical element) 43 that can be inserted and removed is provided on the optical path in front of the second lens group LG2. In the following description, the optical axis direction means a direction parallel to the optical axis O of the photographing optical system, the front means front in the optical axis direction (subject side), and the rear means rear in the optical axis direction (image). Surface side). In the radial direction centered on the optical axis O, the side closer to the optical axis O is the inner diameter side, and the side farther from the optical axis O is the outer diameter side.

  The zoom lens barrel ZL has a cylindrical housing 22 as a fixing member, and the image sensor holder 21 is fixed to the rear portion of the housing 22. The low-pass filter 25 and the image sensor 26 are unitized and fixed to the front surface of the image sensor holder 21.

  The third lens group LG3 is a focus lens group in the zoom lens barrel ZL and is held by the third group lens frame 51. The third group lens frame 51 is supported so as to be linearly movable in the optical axis direction via a guide shaft (not shown), and can be moved back and forth by the driving force of the AF motor 160 (FIG. 18).

  A zooming group (cam ring) block that is driven and controlled by a lens barrel driving motor 150 (FIG. 18) is supported inside the housing 22 separately from the support driving means for the third group lens frame 51. The variable power group (cam ring) block includes a cam ring 11, a feeding cylinder 12, a straight guide ring 13, and a second group lens block 80.

  The cam ring 11 constitutes an external appearance cylinder of the zoom lens barrel ZL together with the feeding cylinder 12, and a guide protrusion (not shown) that is slidably fitted into a cam ring guide groove 22a formed on the inner peripheral surface of the housing 22. ). The cam ring 11 is rotated by receiving a driving force of a zoom gear (not shown) that is rotationally driven by the lens barrel driving motor 150, and moves in the optical axis direction while rotating by the guide of the cam ring guide groove 22a. A straight guide ring 13 is supported in the housing 22. The rectilinear guide ring 13 is guided through a rectilinear guide groove formed on the inner surface of the housing 22 so as to be able to move linearly in the optical axis direction. The rectilinear guide ring 13 can rotate relative to the cam ring 11 and moves together in the optical axis direction. Is bound to.

  As shown in FIGS. 3 and 4, the second group lens block 80 has a configuration in which the polarizing filter unit 40 is fixed to the front portion of the second group lens moving ring 8, and a cylinder constituting the main body portion of the second group lens moving ring 8. The linear guide key 8b protruding in the outer diameter direction from the vicinity of the rear end of the shaped portion 8a is slidable with respect to a linear guide slot (not shown) which is a long hole in the optical axis direction formed in the linear guide ring 13. By being engaged, it is guided straight in the direction of the optical axis. Three rectilinear guide keys 8b are provided at different positions in the circumferential direction, and two of them are shown in FIGS.

  The second lens group LG2 is held by a holding frame portion 8c formed in the cylindrical portion 8a of the second group lens moving ring 8. A polarizing filter unit 40 and a shutter unit 81 are attached to the front part of the second group lens moving ring 8. The shutter unit 81 has a shutter S (FIGS. 1 and 2) that can be opened and closed inside, and drives the shutter S to open and close by an actuator. The polarizing filter unit 40 can insert and remove the polarizing filter 43 on the optical path passing through the optical axis O, and rotate the inserted polarizing filter 43 around the optical axis O, details of which will be described later.

  On the three linear guide keys 8b of the second group lens moving ring 8, a second group cam follower 8d is fixed. The second group cam follower 8d is slidably engaged with a second group control cam groove CG2 formed on the inner peripheral surface of the cam ring 11. Since the second group lens moving frame 8 (second group lens block 80) is guided linearly in the optical axis direction via the linear guide ring 13, when the cam ring 11 rotates, the second group cam follower 8d becomes the second group control cam groove. Under the guidance of CG2, the second group lens moving frame 8 (second group lens block 80) moves along a predetermined locus in the optical axis direction.

  A first lens group LG1 is held in the feeding cylinder 12. The feed cylinder 12 is guided in a straight direction in the optical axis direction by slidably engaging a straight guide key (not shown) provided on the inner surface side with a straight guide groove (not shown) formed in the straight guide ring 13. ing. A first group cam follower 12a is provided on the outer peripheral surface near the rear end of the feeding cylinder 12, and the first group cam follower 12a slides on a first group control cam groove CG1 formed on the inner peripheral surface of the cam ring 11. Engagement possible. Since the feeding cylinder 12 is linearly guided in the optical axis direction via the linear guide ring 13, when the cam ring 11 rotates, the first group cam follower 12a receives the guidance of the first group control cam groove CG1, and the feeding cylinder 12 Moves along a predetermined locus in the optical axis direction.

  FIG. 18 conceptually shows a part of electric parts of a camera on which the zoom lens barrel ZL is mounted. The lens barrel drive motor 150, the AF motor 160, and the shutter unit 81 are controlled by a control circuit (control unit, separation drive mode setting unit) 70. Further, the control circuit 70 performs control described later with respect to the polarizing filter unit 40.

  The zoom lens barrel ZL having the above structure operates as follows. In the photographing state (zoom range) shown in FIG. 1, the cam ring 11 is extended forward in the optical axis direction with respect to the housing 22, and the extension amount of the cam ring 11 is controlled by the locus of the cam ring guide groove 22a. The feeding cylinder 12 that supports the first lens group LG1 and the second group lens block 80 that supports the second lens group LG2 are guided by the cam grooves CG1 and CG2 in accordance with the rotation of the cam ring 11, respectively. Move relative to.

  When the lens barrel drive motor 150 is driven in the lens barrel storage direction from the photographing state shown in FIG. 1, the cam ring 11 that receives the guidance of the cam ring guide groove 22a is moved rearward in the optical axis direction while rotating. The feeding cylinder 12 and the second group lens block 80 (second group lens moving frame 8) move rearward in the optical axis direction together with the cam ring 11 with predetermined relative movement along the locus of the cam grooves CG1 and CG2 on the cam ring 11. To do. When the lens barrel storage state of FIG. 2 is reached, the driving of the lens barrel drive motor 150 in the lens barrel storage direction is stopped. Further, the position of the third lens group frame 51 holding the third lens group LG3 is also controlled by the AF motor 160 so as to be in the retracted position shown in FIG.

  The polarizing filter 43 held by the polarizing filter unit 40 can be arbitrarily inserted and removed in front of the second lens group LG2 and rotated around the optical axis O. The detailed structure of the polarizing filter unit 40 that holds and drives the polarizing filter 43 will be described. As shown in FIG. 5, the polarizing filter unit 40 includes a filter frame (holding member) 42, a polarizing filter 43, an annular friction plate (driven) between a base member (supporting member) 100 and a motor supporting member (supporting member) 41. Rotating member) 44, rotating ring (driven rotating member) 45, driving ring (driven rotating member) 46, friction sheet 47, protective sheet (driven rotating member) 48, resistance applying spring (resistance applying means, biasing member) 49, etc. It is the structure which hold | maintained the member. Each component other than the polarizing filter (rotating optical element) 43 includes a polarizing filter 43, an insertion position where the polarizing filter 43 is located on the optical path of the photographing optical system, and a separation where the polarizing filter 43 is detached from the optical path of the photographing optical system. An insertion / removal drive mechanism configured to be inserted / removed between positions is configured.

  The base member 100 has an annular shape surrounding a circular central opening 100a centered on the optical axis O, and a support surface 100b substantially orthogonal to the optical axis O is formed forwardly around the central opening 100a. The outer peripheral wall portion (detachment control means, cylindrical wall portion) 100c is provided outside the support surface 100b. The outer wall portion 100c is a cylindrical wall portion that protrudes forward from the support surface 100b and has an inner wall surface (inner circumferential surface) with a constant diameter centered on the optical axis O. A filter storage wall (detachment control means, storage wall) 100d is formed continuously with the outer wall 100c. The filter housing wall portion 100d is a wall portion that protrudes in the outer diameter direction from the outer surrounding wall portion 100c and has a partially cylindrical inner wall surface (inner peripheral surface) having a larger curvature than the outer surrounding wall portion 100c. As shown in FIGS. 6 and 9, a sensor hole 100e penetrating in the radial direction is formed in the vicinity of the boundary between the filter housing wall 100d and the outer wall 100c. A regulation wall 100i is formed as a part of the outer wall 100c at the edge of the outer wall 100c facing the sensor hole 100e. A thin plate-like sensor support piece 100j is formed on the outside of the restriction wall portion 100i. In addition, three locking pieces 100f and three locking projections 100h are provided on the outer peripheral side of the outer wall portion 100c at different circumferential positions. Each locking piece 100f protrudes forward and has a hole penetrating in the radial direction.

  A shutter unit 81 is fixed to the rear portion of the base member 100. The shutter unit 81 has an annular portion having an outer diameter substantially the same diameter as the outer wall portion 100c of the base member 100, and the shutter S is stored in the annular portion when opened, and from the annular portion to the inner diameter direction when closed. Protruding. A shutter actuator 82 for driving the shutter S protrudes from the rear portion of the annular portion of the shutter unit 81 (FIGS. 1 and 2). In FIGS. 1 and 2, the base member 100 and the shutter unit 81 are depicted integrally, but the base member 100 and the shutter unit 81 are formed as separate members and then fixed. In the present invention, the shutter unit 81 can be omitted, and the polarizing filter unit 40 may be configured independently without being integrated with the shutter unit 81.

  The motor support member 41 is an annular member having an outer diameter corresponding to the base member 100, a front opening 41 a having a larger diameter than the central opening 100 a is formed on the inner peripheral side, and the base member 100 has an outer periphery on the outer periphery. A sensor support portion 41b is formed at a position corresponding to the sensor hole 100e, and three locking projections 41c are formed at positions corresponding to the three locking pieces 100f. The motor support member 41 and the base member 100 are combined by engaging the three locking protrusions 41c with the corresponding holes of the locking pieces 100f. A separation detection sensor (filter detection sensor) 65 is held on the sensor support portion 41 b of the motor support member 41. The separation detection sensor 65 is also supported by the restriction wall portion 100i of the base member 100 and the sensor support piece 100j in a combined state of a motor support member 41 and a base member 100 described later. The separation detection sensor 65 is a photointerrupter having a light emitting unit and a light receiving unit that are separated in the optical axis direction, detects whether light is incident on the light receiving unit from the light emitting unit, and outputs the detected light to the control circuit 70.

  As shown in FIGS. 11 to 14, an insertion restricting surface 41 d is formed on the inner peripheral portion of the motor support member 41 so as to be located behind the front opening 41 a, and the insertion restricting surface 41 d is arranged in the radial direction behind the insert restricting surface 41 d. A rotation guide surface 41e and a rotation guide surface 41f are formed at different positions in the optical axis direction. The rotation guide surface 41e and the rotation guide surface 41f are both cylindrical inner surfaces with the optical axis O as the center, and the rotation guide surface positioned rearward in the optical axis direction than the rotation guide surface 41e positioned forward in the optical axis direction. 41f has a larger diameter. On the outer peripheral side of the rotation guide surface 41f, an outer peripheral fitting portion 41g that fits the front end of the outer wall portion 100c of the base member 100 is formed. Further, an abutting convex portion 41h protrudes rearward at a position in the optical axis direction between the rotation guide surface 41e and the rotation guide surface 41f. The contact protrusion 41 h is a rearward protrusion formed in an annular region centered on the optical axis O.

  Gear support shafts 60a and 61a parallel to the optical axis O are provided between the motor support portion 41i of the motor support member 41 and the gear support portion 100g of the base member 100, and the first gear 60 and the gear support are provided on the gear support shaft 60a. The second gear 61 is pivotally supported on the shaft 61a (FIG. 14). A filter drive motor (insertion / removal drive mechanism, drive source of the rotating optical element) 180 that is driven and controlled by the control circuit 70 is supported on the front side of the motor support portion 41i. The filter driving motor 180 is a stepping motor having a rotating shaft protruding in a direction parallel to the optical axis O. A pinion 180a is provided on the rotating shaft, and is supported on the end of the motor body on the side where the rotating shaft protrudes. A plate 180b is provided. The filter drive motor 180 is fixed to the motor support member 41 by bringing the support plate 180b into contact with the motor support 41i, and the pinion 180a meshes with the first gear 60 in this fixed state as shown in FIG. The first gear 60 is a two-stage gear including a large diameter gear and a small diameter gear. The pinion 180 a meshes with the large diameter gear of the first gear 60, and the small diameter gear of the first gear 60 meshes with the second gear 61. The second gear 61 meshes with a peripheral gear 46 a formed on the outer periphery of the driving ring 46.

  The driving ring 46 has an annular rotation guide portion 46b centered on the optical axis O on the inner side of the peripheral gear 46a, and an outer peripheral portion near the front end of the rotation guide portion 46b with respect to the rotation guide surface 41e of the motor support member 41. And is slidably supported. By receiving the guidance of the rotation guide surface 41e, the driving ring 46 is supported so as to be rotatable about the optical axis O. When the front end portion of the rotation guide portion 46 b comes into contact with the insertion restriction surface 41 d in the motor support member 41, the movement of the prime ring 46 relative to the motor support member 41 is restricted. The driving ring 46 is further formed with an annular flange 46c extending in the direction orthogonal to the optical axis O on the inner diameter side of the rotation guide portion 46b, and a rotation transmission hole (long hole) 46d penetrating in the optical axis direction on the annular flange 46c. (FIGS. 6, 9, and 11) are formed. The inner edge portion of the annular flange 46 c is a central opening 46 f having a larger diameter than the central opening 100 a of the base member 100. Further, three rear protrusions 46e (FIGS. 7, 10, and 12) are formed on the rear surface side of the annular flange 46c at different positions in the circumferential direction, and the rear protrusions 46e are formed on the base member 100. By abutting against the support surface 100b, the backward movement of the driving ring 46 is restricted (FIG. 12). That is, the driving ring 46 is sandwiched between the insertion restricting surface 41d and the support surface 100b to restrict movement in the optical axis direction with respect to the motor support member 41 and the base member 100, and can rotate around the optical axis O. Yes.

  As shown in FIG. 11 to FIG. 14, the rotating ring 45 is an annular member disposed at a position surrounding the outer side of the rotating guide portion 46 b of the driving ring 46, and the outer peripheral portion thereof is on the rotation guide surface 41 f of the motor support member 41. On the other hand, it is slidably supported. By receiving the guidance of the rotation guide surface 41f, the rotary ring 45 is supported so as to be rotatable about the optical axis O. An annular friction plate 44 is located in front of the rotating ring 45, and a friction sheet 47 is located in front of the annular friction plate 44. Each of the annular friction plate 44 and the friction sheet 47 is a thin annular member centered on the optical axis O and has a diameter size corresponding to the rotating ring 45. The annular friction plate 44 and the rotating ring 45 are coupled by engaging the engaging protrusion 45a provided on the outer peripheral portion of the rotating ring 45 with the engaging piece portion 44a provided on the annular friction plate 44 (FIG. 12). More specifically, a slit for inserting the engagement protrusion 45a is formed in the engagement piece portion 44a, and this slit has a length that allows a slight relative movement of the engagement protrusion 45a in the optical axis direction. On the other hand, in the circumferential direction with the optical axis O as the center, the engagement protrusion 45a is engaged with the slit of the engagement piece 44a with its movement restricted. That is, the rotating ring 45 and the annular friction plate 44 are integrated in the rotating direction and are coupled in a state where a slight relative movement is allowed in the optical axis direction. The friction sheet 47 is inserted between the annular friction plate 44 and the abutting projection 41h of the motor support member 41, and the friction sheet 47 abuts against the abutting projection 41h. The forward movement of the friction plate 44 and the rotating ring 45 is restricted.

  On the other hand, the rotary ring 45 is restricted from moving backward by bringing a plurality of rear protrusions 45b provided on the rear surface side into contact with the support surface 100b of the base member 100 (FIG. 12). That is, the rotating ring 45 is located at the position in the optical axis direction sandwiched between the abutting convex portion 41 h of the motor support member 41 and the support surface 100 b of the base member 100, and the annular friction is caused between the abutting convex portion 41 h and the rotating ring 45. The plate 44 and the friction sheet 47 are inserted. The rotary ring 45 is formed with three spring support holes 45c that open to the front with different circumferential positions, and resistance imparting springs 49 are inserted into the respective spring support holes 45c (FIG. 12). . The resistance applying spring 49 is a compression spring having a front end abutted against the annular friction plate 44 and a rear end abutted against the bottom surface of the spring support hole 45c, and the annular friction plate 44 and the rotating ring 45 are moved in the optical axis direction. Is energized in the separating direction. That is, the annular friction plate 44 is urged forward and the rotary ring 45 is urged rearward. By the urging force of the resistance applying spring 49, the friction sheet 47 is pressed against the abutting convex portion 41h, the rear protrusion 45b of the rotating ring 45 is pressed against the support surface 100b, and the annular friction plate 44 and the rotating ring are pressed. A predetermined amount of frictional resistance is applied to the 45 combined bodies in the rotation direction about the optical axis O. The friction sheet 47 adjusts the amount of friction with respect to the annular friction plate 44, and the friction sheet 47 is omitted when a sufficient frictional force is obtained between the annular friction plate 44 and the abutting projection 41h. It is also possible to do.

  The filter frame 42 is a thin plate member having a generally half-moon shape, and a first support shaft (shaft support portion) 42a and a second support shaft (rotation transmission portion, projection portion) 42b projecting forward are formed near one end portion. A hook-like stopper projection (insertion control means, abutting portion) 42c that is bent in the inner diameter direction is provided at the other end portion. A circular filter opening 42d is formed in the central portion of the filter frame 42, and an outer diameter side edge portion (detachment control means) that forms an arc shape protruding in the outer diameter direction on the outer diameter side and the inner diameter side across the filter opening 42d. , A separation restricting portion) 42e and an inner diameter side edge portion 42f that is substantially linear. A sensor passage piece 42g is formed at a position adjacent to the outer diameter side edge portion 42e. The sensor passage piece 42g is a protrusion that is formed integrally with the main body portion of the filter frame 42 and extends along a plane orthogonal to the optical axis O. A polarizing filter 43 is fixed to the front side of the filter frame 42. The polarizing filter 43 covers the entire filter opening 42d and has a shape that does not overlap the first support shaft 42a, the second support shaft 42b, the stopper projection 42c, and the sensor passage piece 42g.

  As shown in FIG. 11, the first support shaft 42 a of the filter frame 42 is inserted into a shaft hole 45 e formed in the rotary ring 45. The first support shaft 42a has a cylindrical outer peripheral surface shape, and the shaft hole 45e has a corresponding cylindrical inner peripheral surface shape. Accordingly, the filter frame 42 is supported so as to be capable of rotating (swinging) about the first support shaft 42 a with respect to the rotating ring 45. The second support shaft 42 b of the filter frame 42 is fitted into a rotation transmission hole 46 d formed in the driving ring 46. As shown in FIGS. 6 and 9, the second support shaft 42b has a cylindrical outer peripheral shape, while the rotation transmission hole 46d is formed as a long hole in the radial direction centered on the optical axis O. By sandwiching the second support shaft 42b between a pair of opposed inner surfaces of the rotation transmission hole 46d, the rotational force of the driving ring 46 is transmitted to the second support shaft 42b. That is, the filter frame 42 rotates around the optical axis O together with the driving ring 46 due to the fitting relationship between the second support shaft 42 b and the rotation transmission hole 46 d. Since the rotation transmission hole 46d is a long hole in the radial direction, a slight amount of relative movement in the radial direction of the filter frame 42 with respect to the driving ring 46 is allowed.

  The filter frame 42 is inserted at an insertion position (FIGS. 9, 10, 15B to 15F, FIG. 9) where the center of the filter opening 42d coincides with the optical axis O by the operation of a rotary ring 45 and a driving ring 46 described later. 16 (C) to (E), FIG. 17 (A)), and a completely detached position (FIGS. 6, 7, 15A, and 16) where the filter opening 42d is detached from the optical path passing through the optical axis O. (A) and FIG. 17 (F)). At the complete disengagement position of the filter frame 42, the outer diameter side edge portion 42e is close to the inner peripheral surface of the filter storage wall portion 100d, and the rotation of the filter frame 42 in the further disengagement direction (outer diameter direction) It is regulated by the contact between the radial side edge portion 42e and the filter storage wall portion 100d. When the outer diameter side edge portion 42e is at a rotational position that does not correspond to the filter storage wall portion 100d, the outer diameter side edge portion 42e is formed on the inner periphery of the outer wall portion 100c as shown in FIGS. By contacting the surface, the rotation of the filter frame 42 in the detaching direction (outer diametrical direction) from the optical axis O is restricted at the restricting detaching position before (inner diameter side) the complete detaching position. As shown in FIG. 12, with the filter ring 42 supported by the rotating ring 45 and the driving ring 46, the rear protruding portion 45b of the filter frame 42 and the rotating ring 45 are at the same position in the optical axis direction (common light When the filter frame 42 is rotated to the insertion position, the stopper projection 42c comes into contact with one of the plurality of rear protrusions 45b as shown in FIG. Further rotation of 42 in the insertion direction is restricted. The rearward projecting portion 45b that is a contact object of the stopper projection 42c at the insertion position of the filter frame 42 is referred to as a stopper portion (insertion control means, contact portion) 45b-1. The stopper portion 45b-1 may be a portion that only restricts the rotation of the filter frame 42 without contacting the support surface 100b of the base member 100 like the other rear protruding portion 45b.

  A thin protective sheet 48 is supported between the rotary ring 45 and the driving ring 46 and the filter frame 42. The protective sheet 48 has a function of preventing the filter frame 42 from being caught by the rotating ring 45 and the driving ring 46 and performing a smooth operation, and penetrates from the vicinity of the center through which the optical axis O passes toward the outer diameter side. It has a C-shape with an open opening 48a. A pair of positioning holes 48b are formed across the opening 48a, and the positioning protrusions 45d (FIGS. 7 and 10) projecting from the rotary ring 45 are engaged with the positioning holes 48b. Is fixedly supported with respect to the rotating ring 45. In the protective sheet 48, three circumferential elongated holes 48c are formed at different positions in the circumferential direction around the opening 48a. Each of the circumferential elongated holes 48c is an arc-shaped elongated hole centered on the optical axis O, and a rear protrusion 46e of the driving ring 46 is inserted into each circumferential elongated hole 48c. The circumferential elongated hole 48c is longer in the circumferential direction than the rear protrusion 46e, and allows a predetermined amount of relative rotation of the driving ring 46 with respect to the protective sheet 48 and the rotating ring 45. A relief hole 48d is formed which communicates with one of the three circumferential elongated holes 48c and prevents interference with the first support shaft 42a and the second support shaft 42b (FIGS. 5, 10, and 11). ). Further, the protective sheet 48 has a plurality of notches 48e at positions overlapping the rearward protrusion 45b of the rotating ring 45, and does not interfere with the rearward protrusion 45b when supported on the rear part of the rotating ring 45.

  When the polarizing filter unit 40 is assembled, the members are assembled from the rear side with respect to the motor support member 41, and finally the base member 100 is attached to the rear portion of the motor support member 41. Specifically, first, the front end portion of the rotation guide portion 46 b of the driving ring 46 is brought into contact with the insertion restriction surface 41 d of the motor support member 41. As a result, the driving ring 46 is supported so as to be able to rotate about the optical axis along the rotation guide surface 41 e while being restricted from moving forward with respect to the motor support member 41. Subsequently, the combined body of the annular friction plate 44 and the rotating ring 45 is assembled to the motor support member 41 while the friction sheet 47 is sandwiched between the annular friction plate 44 and the contact protrusion 41 h of the motor support member 41. As a result, the annular friction plate 44 and the rotating ring 45 are supported so as to be able to rotate about the optical axis along the rotation guide surface 41 f while being restricted from moving forward with respect to the motor support member 41. The annular friction plate 44 and the rotary ring 45 are preferably assembled in advance as an assembly in which a resistance applying spring 49 is inserted between them. Further, a protective sheet 48 is attached to the rear part of the rotating ring 45, and the rear protrusion 46 e of the driving ring 46 is inserted into the circumferential elongated hole 48 c formed in the protective sheet 48. At this stage, the shaft hole 45e of the rotary ring 45 and the rotation transmission hole 46d of the driving ring 46 are exposed rearward, and the first support shaft 42a corresponding to the shaft hole 45e and the rotation transmission hole 46d, respectively. The filter frame 42 is assembled by inserting the second support shaft 42b. A polarizing filter 43 is attached to the filter frame 42 in advance.

  Finally, the front end of the outer wall portion 100c is fitted to the outer periphery fitting portion 41g, and the three locking protrusions 41c and the locking pieces 100f are engaged, so that the base member 100 is disposed at the rear portion of the motor support member 41. To fix. Each locking projection 41c has a tapered surface that increases the amount of protrusion in the outer diameter direction as it advances from the rear to the front, and when the base member 100 is moved forward relative to the motor support member 41, When the stopper piece 100f is elastically deformed and passes over the tapered surface of the locking protrusion 41c, and the hole of the locking piece 100f reaches a position corresponding to the locking protrusion 41c, the elastic deformation of the locking piece 100f is released and locked. The engaged state with the protrusion 41c is maintained. Thus, in a state where the motor support member 41 and the base member 100 are combined, each member assembled in the motor support member 41 is prevented from falling backward by the support surface 100 b of the base member 100. That is, each member is held between the motor support member 41 and the base member 100. Further, the resistance applying spring 49 is compressed between the annular friction plate 44 and the rotating ring 45, and the frictional resistance described above acts on the annular friction plate 44 and the rotating ring 45.

  The polarizing filter unit 40 (including the shutter unit 81) assembled as described above has the shutter unit 81 in relation to the insertion restricting portion 8e (FIGS. 1, 2, and 4) formed at the front end of the cylindrical portion 8a. The rear part is brought into contact, and is fixed to the front part of the second group lens moving ring 8. The second group lens moving ring 8 has three locking pieces 8f protruding forward from the cylindrical portion 8a, and each of the locking pieces 8f is engaged with a locking protrusion 100h of the base member 100, whereby a polarizing filter is obtained. The unit 40 is fixed. Each locking piece 8f has a hole penetrating in the radial direction. Each locking protrusion 100h has a tapered surface that increases the amount of protrusion in the outer diameter direction as it advances from the rear to the front, and moves the second group lens moving ring 8 relatively forward with respect to the polarizing filter unit 40. Then, when the locking piece 8f is elastically deformed, the locking piece 8f gets over the tapered surface of the locking projection 100h, and when the hole of the locking piece 8f reaches a position corresponding to the locking projection 100h, the elastic deformation of the locking piece 8f is released. Thus, the engaged state with the locking protrusion 100h is maintained.

  As shown in FIG. 18, a camera in which the zoom lens barrel ZL is mounted has a filter insertion switch 71, a filter separation switch (input unit, rotating optical element separation switch) 72, a filter as operation means related to the polarization filter unit 40. A rotation switch 73 and a power switch (input unit) 74 are provided. When the filter insertion switch 71 is operated when the polarizing filter 43 is in the complete removal position, an insertion drive instruction signal is input from the filter insertion switch 71 to the control circuit 70. When the filter separation switch 72 is operated while the polarizing filter 43 is in the insertion position, a separation drive instruction signal is input from the filter separation switch 72 to the control circuit 70. When the filter rotation switch 73 is operated, a filter rotation instruction signal is input from the filter rotation switch 73 to the control circuit 70. The power switch 74 switches the on / off state of the power supply of the camera. When the power switch 74 is switched from on to off when the polarizing filter 43 is in the insertion position, the power switch 74 sends a separation drive instruction signal to the control circuit 70. Enter.

  When the separation drive instruction signal is input from the filter separation switch 72, the control circuit (detachment drive mode setting unit) 70 sets a “vignetting prevention priority separation drive mode” to be described later as the separation drive mode of the polarizing filter 43. On the other hand, when a separation drive instruction signal is input from the power switch 74, the control circuit (separation drive mode setting unit) 70 sets a “speed priority separation drive mode” to be described later as the separation drive mode of the polarizing filter 43.

  As shown in FIG. 18, the camera on which the zoom lens barrel ZL is mounted is provided with a detachment drive mode changeover switch (detachment drive mode setting unit) 75 as operation means related to the polarization filter unit 40. By operating the separation drive mode changeover switch 75, the separation drive mode of the polarizing filter 43 is changed to “vignetting” by manual operation based on the user's preference, instead of the automatic setting by the control circuit (detachment drive mode setting unit) 70 described above. It is switched between “prevention priority separation drive mode” and “speed priority separation drive mode”. When none of the separation drive modes is set by the separation drive mode changeover switch 75, the separation drive mode can be automatically set by the control circuit (detachment drive mode setting unit) 70 described above. .

  As shown in FIG. 18, in a camera in which the zoom lens barrel ZL is mounted, a rotation angle position detection sensor (insertion / removal drive mechanism, which detects the rotation angle position of the polarization filter 43 as sensors relating to the polarization filter unit 40). Detection unit) 66 is provided. The rotation angle position detection sensor 66 is composed of, for example, a Hall IC provided in the filter drive motor 180. By reading the output of the Hall IC, the rotation angle position of the polarizing filter 43 according to the rotation angle of the rotor of the filter drive motor 180 is obtained. Is detected.

  The operation of the polarizing filter unit 40 having the above configuration will be described. As described above, the polarizing filter unit 40 holds annular members such as the annular friction plate 44, the rotating ring 45, the driving ring 46, the friction sheet 47, and the protective sheet 48 between the motor support member 41 and the base member 100. The central opening 100a of the base member 100 has a smaller diameter than the opening that each of these members has on the optical path (optical axis O) (see FIGS. 11 to 14). That is, the minimum opening on the optical path in the polarizing filter unit 40 excluding the filter frame 42 and the polarizing filter 43 is defined by the central opening 100a of the base member 100 (in other words, the filter frame 42 and the polarizing filter 43 have a central opening). 100a). The polarizing filter 43 can be in an insertion state that advances to the front of the central opening 100a and a separation state that separates to the outer diameter side of the central opening 100a, and further rotates around the optical axis O in the insertion state. (Spinning) can be performed. The polarization filter 43 is inserted into and removed from the optical path by rotating the insertion position and the complete removal position of the filter frame 42 described above. The rotation of the polarization filter 43 in the insertion state is the rotation of the rotary ring 45 and the driving ring 46. Is done by.

  More specifically, the operation of the polarizing filter unit 40 for inserting / removing the polarizing filter 43 includes “differential rotation operation from the complete removal position of the filter frame 42 to the insertion position” and “at the insertion position of the filter frame 42. There are roughly four types: “forward rotation operation with rotation”, “differential rotation operation from the insertion position of the filter frame 42 to the limit release position”, and “reverse rotation operation with the filter frame 42 at the limit release position”. Is done. Below, each of these operation | movement is demonstrated in detail.

“Differential rotation of filter frame 42 from fully detached position to inserted position”
6, FIG. 7, FIG. 15 (A), FIG. 16 (A), and FIG. 17 (F) show the detached state of the polarizing filter 43. FIG. The filter frame 42 is in a completely disengaged position that has entered the filter storage wall portion 100d of the base member 100, and an outer diameter side edge portion 42e is positioned along the inner wall surface of the filter storage wall portion 100d. The above rotation in the direction of the disengagement position (outer diameter direction) is restricted. The inner diameter side edge portion 42f of the filter frame 42 is located on the outer diameter side of the central opening 100a of the base member 100, and the filter frame 42 does not block the light beam passing through the central opening 100a. The sensor passage piece 42g of the filter frame 42 enters between the light emitting portion and the light receiving portion of the photo interrupter constituting the separation detection sensor 65 through the sensor hole 100e. The sensor passage piece 42g blocks light from entering the light-receiving portion of the photo interrupter, so that it is detected that the filter frame 42 is at the complete separation position.

  The operation of inserting the polarizing filter 43 is executed by operating the filter insertion switch 71. When the polarizing filter 43 is inserted, the driving ring 46 is rotated in the N1 direction of FIGS. N1 is the rotation in the direction in which the polarizing filter 43 is inserted. When the driving ring 46 rotates in the N1 direction, a force in the rotational direction about the optical axis is transmitted from the side surface of the rotation transmission hole 46d to the second support shaft 42b of the filter frame 42. Here, a frictional resistance in the rotational direction acts on the rotating ring 45 that supports the first support shaft 42a of the filter frame 42 by the shaft hole 45e, and the urging force of the resistance applying spring 49 acts, and the first support shaft 42a. The filter frame 42, in which the second support shaft 42b in the eccentric position is pressed in the N1 direction by the driving ring 46, is moved from the complete disengagement position to the insertion position centering on the axes of the first support shaft 42a and the shaft hole 45e. Try to rotate. However, the regulating wall portion 100i of the base member 100 is located on the radially inner side near the optical axis O so as to face the sensor passage piece 42g of the filter frame 42 inserted into the sensor hole 100e, and the sensor passage piece 42g. The rotation of the filter frame 42 in the direction of the insertion position is restricted by the contact of the restriction wall portion 100i. Then, the rotational driving force in the N1 direction transmitted from the filter frame 42 to the rotating ring 45 by fitting the first support shaft 42a and the shaft hole 45e exceeds the frictional resistance due to the biasing force of the resistance applying spring 49, and the rotating ring 45 (A combined body of the annular friction plate 44, the rotating ring 45, and the protective sheet 48) rotates in the N1 direction together with the driving ring 46. The filter frame 42 also rotates in the N1 direction along with the rotary ring 45, and the sensor passage piece 42g comes out of the sensor hole 100e.

  Thereby, the restriction | limiting by the restriction | limiting wall part 100i is cancelled | released, and the filter frame 42 becomes rotatable to an insertion position. The urging force of the resistance applying spring 49 is a magnitude that gives a frictional resistance that does not rotate the rotating ring 45 by rotating only the filter frame 42 in the insertion / removal direction when the rotation of the filter frame 42 in the insertion / removal direction is not restricted. Is set to Therefore, when the sensor passage piece 42g is removed from the sensor hole 100e, the rotating ring 45 is stopped without being rotated with the driving ring 46, and the second support shaft 42b is pressed in the N1 direction by the driving ring 46. The filter frame 42 starts to rotate from the complete disengagement position toward the insertion position around the axis of the first support shaft 42a and the shaft hole 45e (FIG. 16B). At the time of relative rotation of the driving ring 46 with respect to the rotating ring 45, the rear protrusion 46e moves in the circumferential direction in the circumferential elongated hole 48c, and the protective sheet 48 does not hinder the rotation of the driving ring 46.

  When the filter frame 42 reaches the insertion position shown in FIGS. 9, 10, 15 (B), and 16 (C), a stopper portion 45 b-1 (one of the plurality of rearward protruding portions 45 b provided on the rotating ring 45 is provided. The stopper projection 42c comes into contact with the At this time, the center of the filter opening 42d of the filter frame 42 coincides with the optical axis O, and the polarizing filter 43 is inserted on the optical path in front of the central opening 100a of the base member 100. When the stopper projection 42c comes into contact with the stopper portion 45b-1, the rotation of the filter frame 42 relative to the rotating ring 45 in the insertion position direction is restricted.

“Rotating forward rotation at the insertion position of the filter frame 42”
With the filter frame 42 in the insertion position, the polarizing filter 43 can be rotated about the optical axis according to the operation of the filter rotation switch 73. When rotating the optical axis center of the polarizing filter 43, the driving ring 46 is rotated in the N1 direction by the filter drive motor 180. Then, the rotational force in the N1 direction is transmitted to the filter frame 42 by the fitting relationship between the rotation transmission hole 46d and the second support shaft 42b. Here, since the rotation of the filter frame 42 in the insertion position direction with respect to the rotating ring 45 is restricted by the contact between the stopper projection 42c and the stopper portion 45b-1, the first support shaft 42a and the shaft hole 45e are fitted. Thus, the rotational driving force in the N1 direction transmitted from the filter frame 42 to the rotary ring 45 exceeds the frictional resistance by the biasing force of the resistance applying spring 49, and the rotary ring 45 (the annular friction plate 44, the rotary ring 45, and the protective sheet 48). The combined body) rotates in the N1 direction together with the driving ring 46 (FIGS. 15C to 15F and FIGS. 16D to 16E). In the state where the rotating ring 45 and the driving ring 46 are rotated, the relative position of the shaft hole 45e into which the first support shaft 42a and the second support shaft 42b of the filter frame 42 are inserted and the rotation transmission hole 46d does not change. 42 rotates around the optical axis O together with the rotating ring 45 and the driving ring 46 while maintaining the insertion position where the polarizing filter 43 is inserted on the optical path. That is, the polarizing filter 43 is rotated about the optical axis O. When the filter drive motor 180 is stopped, the rotation of the polarizing filter 43 is stopped.

"Differential rotation operation from insertion position of filter frame 42 to restriction release position"
The operation of removing the polarizing filter 43 is executed by operating the filter leaving switch 72. When the polarizing filter 43 is detached, the driving ring 46 is rotated in the N2 direction in FIG. N2 is a rotation in a direction in which the polarizing filter 43 is detached. When the rotational force in the N2 direction of the driving ring 46 is transmitted to the filter frame 42 via the rotation transmission hole 46d and the second support shaft 42b, the filter frame 42 is connected to the first support shaft 42a with respect to the rotation ring 45. Around the axis of the shaft hole 45e, the stopper protrusion 42c is rotated away from the stopper portion 45b-1, that is, from the insertion position to the separation position. At this time, the frictional resistance due to the urging force of the resistance applying spring 49 acts on the rotating ring 45, and the rotating ring 45 keeps the stopped state without being rotated with the driving ring 46. When the filter frame 42 rotates toward the separation position, the outer diameter side edge portion 42e of the filter frame 42 contacts the inner wall surface of the outer wall portion 100c of the base member 100 as shown in FIG. The frame 42 is stopped at the limit detachment position where the detachment amount is smaller than the complete detachment position. In this limit detachment position, there is a possibility that the inner diameter side edge portion 42f of the filter frame 42 is located on the inner diameter side of the central opening 100a of the base member 100, and the inner diameter side edge portion 42f may block the light beam passing through the central opening 100a. is there.

“Reverse rotation of the filter frame 42 at the limit release position”
When the driving ring 46 is further rotated in the N2 direction while the filter frame 42 is in the limit separation position, the N2 direction transmitted to the rotating ring 45 by the fitting of the first support shaft 42a and the shaft hole 45e of the filter frame 42 is transmitted. The rotational driving force exceeds the frictional resistance due to the urging force of the resistance applying spring 49, and the rotating ring 45 (the combined body of the annular friction plate 44, the rotating ring 45 and the protective sheet 48) rotates together with the driving ring 46. When the rotating ring 45 and the driving ring 46 are rotated in the N2 direction, the filter frame 42 is moved while the outer diameter side edge portion 42e is slidably contacted with the outer wall portion 100c as shown in FIGS. A rotation operation in the N2 direction around the optical axis O is performed.

  Here, when the filter frame 42 rotates in the N2 direction at the limit detachment position, the inner diameter side edge portion 42f of the filter frame 42 rotates around the optical axis O so as to draw a virtual circle on the inner diameter side of the central opening 100a. Move. For this reason, when the diameter of the effective light beam of the imaging optical system (defined by the variable aperture diameter of the variable aperture stop) is larger than the diameter of the virtual circle, the inner edge 42f of the filter frame 42 is accompanied by the detachment drive. Vignetting occurs by blocking the effective light flux of the photographic optical system.

  When the filter frame 42 is rotated in the N2 direction to a position exceeding the boundary between the outer wall portion 100c and the filter storage wall portion 100d of the base member 100, the filter frame 42 is held in the restricted release position by the outer wall portion 100c. As shown in FIG. 17E, the outer diameter side edge portion 42e is rotated in the direction of the disengagement position until the outer diameter side edge portion 42e is brought into contact with the inner wall surface of the filter storage wall portion 100d. It is continuously rotated in the N2 direction while being in sliding contact with the inner wall surface of the portion 100d. Since the inner wall surface of the outer wall portion 100c is a cylindrical surface centered on the optical axis O, the filter frame 42 is in sliding contact with the outer diameter side edge portion 42e with respect to the outer wall portion 100c. In the state (D), the rotating ring 45 and the driving ring 46 are rotated together. On the other hand, since the inner wall surface of the filter storage wall portion 100d is a curved surface having a larger curvature than the inner wall surface of the outer surrounding wall portion 100c, the outer edge portion 42e is moved along the inner wall surface of the filter storage wall portion 100d. The filter frame 42 is rotated (rotated) about the axes of the first support shaft 42a and the shaft hole 45e in addition to the rotation operation in the N2 direction about the optical axis O (rotation associated with the driving ring 46). Relative rotation with respect to the ring 45) is also performed. At the time of relative rotation of the filter frame 42 with respect to the rotating ring 45, per unit time between the driving ring 46 that continues to rotate in the N <b> 2 direction and the rotating ring 45 that tries to stop rotating due to frictional resistance by the resistance applying spring 49. The rotational amount of the driving ring 46 is larger than that of the rotating ring 45. As a result, the filter frame 42 is rotated to the complete removal position. In other words, the inner wall surface of the filter storage wall portion 100d functions as a guide surface that guides the filter frame 42 from the limit release position to the complete release position. At the final stage of the separation operation of the filter frame 42, the sensor passage piece 42g enters between the light emitting portion and the light receiving portion of the separation detection sensor 65 through the sensor hole 100e, and the filter frame 42 reaches the complete separation position. Detected. In response to this sensor detection, the filter drive motor 180 is stopped, and the separation operation of the polarizing filter 43 is completed (FIG. 17F). In other words, the filter frame 42 is reliably obtained by the combined operation of the rotation of the optical axis center (N2 direction) and the rotation about the first support shaft 42a when guided by the inner wall surface of the filter storage wall 100d. In addition, the sensor passing piece 42g is made to enter the detection position by the separation detection sensor 65 as well as reaching the complete separation position.

  Note that when the separation operation of the filter frame 42 is started from a specific rotational direction position, FIG. 17 (E) from the beginning without passing through the stage of the limited separation position where the outer diameter side edge portion 42e contacts the outer wall portion 100c. ) To contact the inner wall surface of the filter storage wall 100d. Also in this case, the final stage of the detachment operation is the same as described above, and the filter frame 42 rotates in the N2 direction while rotating around the first support shaft 42a, and the sensor passage piece 42g is moved to the sensor hole 100e. Enter to reach the complete exit position.

  In this embodiment, when the filter frame 42 is in the insertion position, when a separation drive instruction signal is input from the filter separation switch 72 or the power switch 74 to the control circuit (control unit) 70, the separation drive mode of the polarizing filter 43 is set. Depending on whether the vignetting prevention priority separation drive mode or the speed priority separation drive mode is set, the control for separating the polarization filter 43 by the control circuit (control unit) 70 is used differently. ing. Hereinafter, the separation drive control of the polarizing filter 43 in the “vignetting prevention priority separation drive mode” and the “speed priority separation drive mode” will be described in detail.

  In describing the separation drive control of the polarization filter 43 in the “vignetting prevention priority separation drive mode” and the “speed priority separation drive mode”, the concept of “position immediately before separation” of the filter frame 42 is important. As shown in FIG. 19, the “position immediately before separation” of the filter frame 42 is included as a part of the limit separation position of the filter frame 42, and the filter frame 42 is only α ° by the “rotating reverse rotation operation”. This means the position at which the filter frame 42 moves from the restricted release position to the complete release position when it rotates. The rotational movement amount α ° of the filter frame 42 at the time of transition from the limited release position to the complete release position is 0 ° <α ° <180 °, preferably 0 ° <α ° <90 °, more preferably 0 ° <. It can be set within a range satisfying α ° <30 °. In “Episode prevention priority separation drive mode” and “Speed priority separation drive mode”, control passes through this “position immediately before separation” immediately before the transition to the complete separation position, but is controlled until this position immediately before separation is reached. Are very different.

"Episode prevention priority separation drive mode"
This mode prevents the vignetting from occurring due to the filter frame 42 (inner diameter side edge portion 42f) blocking the effective light beam of the photographing optical system even at some sacrifice of the driving speed for removing the polarizing filter 43. It is aimed.

  As shown in FIGS. 20A to 20B, when receiving the separation drive instruction signal, the control circuit 70 rotates the driving ring 46 in the N1 direction by the filter drive motor 180, whereby the filter frame 42 is moved. Until the rotation angle position corresponding to the position immediately before the separation is reached, the “rotating forward rotation operation” is performed while the filter frame 42 remains in the insertion position. During this “rotating forward rotation operation”, the filter frame 42 does not block the effective light beam of the photographing optical system, and vignetting does not occur.

  As shown in FIG. 20C, the control circuit 70 rotates the driving ring 46 in the N2 direction by the filter drive motor 180 after the filter frame 42 has reached the rotation angle position corresponding to the position immediately before the separation. The differential rotation operation "is performed to move the filter frame 42 from the insertion position to the position immediately before the removal. For the first time at the position immediately before the separation, the filter frame 42 may block the effective light beam of the photographing optical system and may cause vignetting. In FIG. 20C, portions of the filter frame 42 that may cause vignetting are shaded.

  As shown in FIGS. 20C to 20E, the control circuit 70 moves the filter frame 42 from the insertion position to the position immediately before the removal, and further rotates the driving ring 46 in the N2 direction by the filter drive motor 180. As a result, the “rotating reverse rotation operation” is performed to move the filter frame 42 from the position immediately before the separation to the complete separation position.

  In this way, in the “vignetting prevention priority separation drive mode”, the “differential rotation operation” is performed after the filter frame 42 is rotated to the rotation angle position corresponding to the position immediately before the separation with the “following forward rotation operation” in the inserted state. As a result, the filter frame 42 is shifted from the insertion position to the position immediately before removal. That is, by shortening the time during which the filter frame 42 is at the limit separation position to the limit, it is possible to effectively prevent the vignetting from occurring due to the filter frame 42 blocking the effective light beam of the photographing optical system.

"Speed priority release drive mode"
The purpose of this mode is to drive the polarizing filter 43 as soon as possible without considering the occurrence of vignetting accompanying the driving of the polarizing filter 43 as a problem.

  When receiving the separation drive instruction signal, the control circuit 70 acquires the rotation angle position of the polarizing filter 42 from the rotation angle position detection sensor 66 when the separation drive instruction signal is input.

  Based on the obtained rotation angle position of the polarizing filter 42, the control circuit 70 shifts the filter frame 42 from the insertion position to the restriction release position by “differential rotation operation” and then performs “rotation reverse rotation operation” to filter the filter frame 42. 42 when the filter frame 42 is positioned at a position immediately before separation, and after the filter frame 42 has reached a rotation angle position corresponding to the position immediately before separation by “accompanying forward rotation operation”, immediately before the filter frame 42 is removed by “differential rotation operation”. Of the cases where it is positioned at the position, the operation having the shorter time is selected and executed.

  More specifically, as shown in FIG. 21, the control circuit 70 sets β as the rotation angle position of the polarizing filter 42 at the position immediately before separation, and γ as the rotation angle position of the polarization filter 42 when the separation drive instruction signal is input. At this time, it is determined whether or not β + 180 <γ (however, a clockwise rotation (N1 direction) in FIG. 21 is set to a positive value) is established.

  When it is determined that β + 180 <γ is satisfied (for example, γ1 in FIG. 21), the control circuit 70 causes the filter frame 42 to reach the rotation angle position corresponding to the position immediately before the separation by the “following forward rotation operation”. Thereafter, an operation of positioning the filter frame 42 at a position immediately before the separation is performed by “differential rotation operation”.

  When the control circuit 70 determines that β + 180 <γ does not hold (for example, γ2 in FIG. 21), the control circuit 70 shifts the filter frame 42 from the insertion position to the limit release position by “differential rotation operation”, By the “reverse rotation operation”, the filter frame 42 is moved to the position immediately before separation.

  The control circuit 70 causes the filter frame 42 to move from the position immediately before the removal to the complete removal position by causing the filter frame 42 to move to the position immediately before the removal, and to perform a “reverse rotation operation”.

  As described above, in the “speed priority separation drive mode”, an operation that can quickly move the filter frame 42 to the position immediately before separation is selected based on the rotation angle position of the polarizing filter 42 at the time when the separation drive instruction signal is input. Running. As a result, it is possible to shorten the separation drive time required from when the separation drive instruction signal is input to when the polarizing filter 42 is shifted to the complete separation position.

  Next, the control contents by the control circuit 70 when the polarizing filter 43 is driven to be detached will be described with reference to the flowchart of FIG.

  When the filter separation switch 72 or the power switch 74 is operated in the power-on state where the filter frame 42 (polarization filter 43) is in the insertion position (step S1: YES), the control circuit 70 is operated from the filter separation switch 72 or the power switch 74. The separation drive instruction signal is input to (step S2).

  The control circuit 70 determines whether one of the “vignetting prevention priority separation drive mode” and the “speed priority separation drive mode” is set as the polarization filter separation drive mode (steps S3 and S4).

  When the “vignetting prevention priority separation drive mode” is set (step S3: YES), the control circuit 70 reaches the rotation angle position corresponding to the position immediately before the separation by the “following forward rotation operation”. After that, the filter frame 42 is positioned at the position immediately before separation by “differential rotation operation” (step S5).

  When the “speed priority separation drive mode” is set (step S3: NO, step S4: YES), the control circuit 70 rotates the rotation angle position γ of the polarizing filter 42 at the time when the separation drive instruction signal is input. Obtained from the angular position detection sensor 66 (step S6).

  Further, the control circuit 70 determines whether or not β + 180 <γ is satisfied when the rotation angle position of the polarizing filter 42 at the position immediately before separation is β (step S7).

  When the control circuit 70 determines that β + 180 <γ is satisfied (step S7: YES), the control circuit 70 causes the filter frame 42 to reach the rotation angle position corresponding to the position immediately before the separation by “accompanying forward rotation operation”, and then “difference”. By the “dynamic rotation operation”, the filter frame 42 is positioned at a position immediately before separation (step S5).

  When the control circuit 70 determines that β + 180 <γ is not satisfied (step S7: NO), the control circuit 70 shifts the filter frame 42 from the insertion position to the restricted release position by “differential rotation operation”, and then “rotates reverse rotation”. By the “operation”, the filter frame 42 is positioned at a position immediately before separation (step S8).

  Note that the control circuit 70 sets “differential rotation operation” when neither the “vignetting prevention priority separation drive mode” nor the “speed priority separation drive mode” is set (step S3: NO, step S4: NO). After the filter frame 42 is shifted from the insertion position to the limit separation position by the above, the filter frame 42 is positioned at the position immediately before the separation by the “rotating reverse rotation operation” (step S8).

  Finally, the control circuit 70 shifts the filter frame 42 from the position immediately before the separation to the complete separation position by the “accompanying reverse rotation operation” (step S9).

  As described above, according to the imaging apparatus of the present embodiment, when the control unit (70) receives the separation drive instruction signal from the input unit (72, 74), the separation drive mode setting unit (70, 75) Depending on whether the vignetting prevention priority separation drive mode or the speed priority separation drive mode is set, the separation drive of the rotating optical element 43 by the insertion / removal drive mechanism is controlled in a different manner. As a result, when the rotary optical element 43 is driven to be detached from the insertion position to the separation position, it is optimal whether to give priority to prevention of vignetting or priority to the speed of separation driving depending on the use situation and user preference. Can be set.

  In the polarizing filter unit of the above embodiment, the insertion / removal operation of the polarizing filter 43 on the optical path and the rotating operation of the polarizing filter 43 on the optical path are performed by switching between relative rotation of the rotating ring 45 and the driving ring 46 and integral rotation. The filter frame 42 that is held and is moved in the insertion / removal direction while holding the polarizing filter 43 is a small and light thin plate member that does not have a complicated movable part. For this reason, it is possible to reduce the thickness of the drive mechanism of the polarizing filter 43 in the optical axis direction. In addition, the driving load when operating the polarizing filter 43 can be reduced, and the power saving performance and the response of the operation are excellent.

  Further, when the polarizing filter 43 is moved away from the optical path, it can be moved only at a specific rotational position at a position where the polarizing filter 43 is completely removed from the optical path. The filter frame 42 is allowed to rotate around the optical axis while restricting the rotation of the filter frame 42 at a small limit release position. Thereby, it is not necessary to make the diameter size of the polarizing filter unit corresponding to the complete disengagement position over the entire circumference, and the enlargement of the polarizing filter unit in the radial direction can be prevented. In addition, since the complete disengagement position of the filter frame 42 is set at a specific position in the rotation direction, the disengagement state can be reliably detected with a simple configuration by the disengagement detection sensor 65. The part for controlling the separation operation with respect to the filter frame 42 is formed in the form of a wall surface or a cam surface on the base member 100 or the motor support member 41 which is a support member for the movable member constituting the polarization filter unit. Therefore, it is structurally space-saving and simple, and can be manufactured at low cost.

  Although the present invention has been described based on the illustrated embodiment, the present invention is not limited to the illustrated embodiment, and the details of the driving device for the polarizing filter 43 are different from the illustrated embodiment without departing from the gist of the invention. It is also possible to adopt.

  For example, in the polarizing filter unit of the illustrated embodiment, when the filter frame 42 is in the completely detached position, the filter frame 42 moves toward the insertion position by the engagement of the sensor passage piece 42g and the restriction wall portion 100i of the base member 100. Although the rotation is restricted, the present invention is effective even if the separation holding structure by the restriction wall portion 100i is omitted. In this case, when the driving ring 46 is rotationally driven in the N1 direction in FIG. 6 in the filter detached state of FIG. 6, the rotation ring 45 is not rotated and the filter frame 42 is inserted into the insertion position of the first support shaft 42a. The rotation can be started immediately.

  In the illustrated embodiment, the operation of the filter insertion switch 71, the filter removal switch 72, and the filter rotation switch 73 causes the insertion / removal operation of the polarizing filter 43 and the rotation operation on the optical path. The polarizing filter 43 may be operated by. Alternatively, the present invention can also be applied to an optical apparatus that operates the polarizing filter 43 by automatic control without being manually operated.

  In the illustrated embodiment, the polarizing filter 43 is applied as the rotating optical element. However, in addition to the polarizing filter, a cross filter, a multi-face effect filter, or the like produces an optical effect by rotating in a state inserted in the optical path. The present invention is applicable to any optical element driving device.

LG1 1st lens group LG2 2nd lens group LG3 3rd lens group O Optical axis S Shutter ZL Zoom lens barrel 8 2nd lens moving ring 8e Insertion restricting part 8f Locking piece 11 Cam ring 12 Feeding cylinder 13 Straight guide ring 21 Image sensor holder 22 Housing 26 Image sensor 40 Polarizing filter unit 41 Motor support member (insertion / removal drive mechanism, support member)
41a Front opening 41b Sensor support part 41c Locking protrusion 41d Insertion restricting surface 41e 41f Rotation guide surface 41g Outer periphery fitting part 41h Contacting convex part 41i Motor support part 42 Filter frame (insertion / removal drive mechanism, holding member)
42a First support shaft (shaft support)
42b 2nd support shaft (rotation transmission part, projection part)
42c Stopper projection (insertion control means, contact part)
42d Filter opening 42e Outside diameter side edge (separation control means, detachment regulating part)
42f Inner diameter side edge part 42g Sensor passage piece 43 Polarizing filter (rotating optical element)
44 Annular friction plate (insertion / removal drive mechanism, driven rotating member)
44a Engagement piece 45 Rotating ring (insertion / removal drive mechanism, driven rotation member)
45a Engaging projection 45b Backward projecting part 45b-1 Stopper part (insertion control means, contact part)
45c Spring support hole 45d Positioning protrusion 45e Shaft hole 46 Driving ring (insertion / removal drive mechanism, driving rotation member)
46a peripheral gear 46b rotation guide part 46c annular flange 46d rotation transmission hole (long hole)
46e Rear protrusion 46f Center opening 47 Friction sheet (insertion / removal drive mechanism)
48 Protection sheet (insertion / removal drive mechanism, driven rotating member)
48a Opening opening 48b Positioning hole 48c Circumferential elongate hole 48d Escape hole 48e Notch 49 Resistance application spring (insertion / removal drive mechanism, resistance application means, biasing member)
51 Third lens group frame 60 First gear 60a Gear support shaft 61 Second gear 61a Gear support shaft 65 Detachment detection sensor (filter detection sensor)
66 Rotation angle position detection sensor (insertion / removal drive mechanism, detection unit)
70 Control circuit (control unit, separation drive mode setting unit)
71 Filter insertion switch 72 Filter separation switch (input unit, rotating optical element separation switch)
73 Filter rotation switch 74 Power switch (input unit)
75 Detachment drive mode switch (separation drive mode setting part)
80 Second lens block 81 Shutter unit 82 Shutter actuator 100 Base member (insertion / removal drive mechanism, support member)
100a Center opening 100b Support surface 100c Outer wall part (detachment control means, cylindrical wall part)
100d Filter storage wall (detachment control means, storage wall)
100e Sensor hole 100f Locking piece 100g Gear support part 100h Locking protrusion 100i Restriction wall part 100j Sensor support piece 150 Lens barrel drive motor 160 AF motor 180 Filter drive motor (insertion / removal drive mechanism, drive source of rotating optical element)
180a pinion 180b support plate

Claims (8)

A rotating optical element that rotates about the optical axis of the imaging optical system on the optical path of the imaging optical system;
An insertion / removal drive mechanism that drives the rotation optical element to be inserted / removed between an insertion position on the optical path of the photographing optical system and a separation position from the optical path;
An input unit for inputting a separation drive instruction signal for driving the rotation optical element from the insertion position to the separation position;
A detachment drive mode setting unit that sets either a vignetting prevention priority separation drive mode or a speed priority separation drive mode; and a separation drive mode set by the separation drive mode setting unit when the input unit inputs a separation drive instruction signal And a control unit that controls, in a different manner, the detachment driving of the rotating optical element by the insertion / removal driving mechanism;
An imaging apparatus comprising: The imaging device according to claim 1,
The insertion / removal drive mechanism is
A support member;
A driving rotating member supported by the supporting member so as to be rotatable in a direction around the optical axis of the photographing optical system, and driven to rotate in the rotating direction by a driving source;
A driven rotary member supported by the support member so as to be rotatable in a direction around the optical axis and capable of relative rotation in the rotational direction with respect to the driving rotary member;
Resistance applying means for applying rotational resistance to the driven rotating member;
A rotation transmitting portion that holds the rotating optical element and transmits a force in the rotational direction from the driving rotating member; and a shaft supporting portion with respect to the driven rotating member; A holding member for rotating and inserting the rotating optical element on the optical path;
An insertion control means for restricting rotation of the holding member at an insertion position on the optical path; and movement relative to the holding member at a specific position in a rotational direction around the optical axis to a complete detachment position from the optical path. Detachment control means for restricting rotation at a limited detachment position where the amount of movement in the detachment direction is smaller than the complete detachment position other than the specific position in the rotational direction,
The insertion / removal drive mechanism is
The driven rotation member and the driving rotation member that receive the rotation resistance by the resistance applying unit by rotating the driving rotation member in a direction in which the holding member is not subjected to the rotation restriction by the insertion control unit and the separation control unit. Differential rotation operation in which a differential in the rotation direction is generated between the holding member and the holding member rotates in the insertion / removal direction around the shaft support portion;
When the holding member is in the insertion position, the holding member rotates the driving rotation member in a direction to receive the rotation restriction by the insertion control unit, thereby resisting the rotation resistance by the resistance applying unit. A follow-up rotation operation in which the driven rotation member and the holding member rotate together with the driving rotation member around the optical axis; and when the holding member is in the restricted release position, the holding member is driven by the release control means. By rotating the driving rotation member in a direction subject to the rotation restriction, the driven rotation member and the holding member rotate together with the driving rotation member against the rotation resistance by the resistance applying unit, and the rotation direction is specified. An imaging apparatus that performs a reverse rotation operation in which the holding member is rotated to the complete disengagement position at a position. The imaging device according to claim 2,
The limited disengagement position includes a position immediately before disengagement where the retaining member shifts from the restrictive disengagement position to the complete disengagement position when the retaining member is rotated by a predetermined amount by the accompanying reverse rotation operation.
The control unit, when the input unit inputs a separation drive instruction signal, when the separation drive mode setting unit is setting the vignetting prevention priority separation drive mode, to the insertion / removal drive mechanism,
(1) An operation step of performing the revolving positive rotation operation while keeping the holding member in the insertion position until the holding member reaches a rotation angle position corresponding to the position immediately before the separation;
(2) an operation step of causing the differential rotation operation to be performed after the holding member has reached a rotational angle position corresponding to the position immediately before separation, and causing the holding member to shift from the insertion position to the position immediately before separation; (3) Photographing that performs an operation step of causing the holding member to shift from the position immediately before separation to the complete separation position by performing the reverse rotation operation after the holding member is moved to the position immediately before separation. apparatus. The imaging device according to claim 2,
The insertion / removal drive mechanism further includes a detection unit that detects a rotation angle position of the rotary optical element at a time when the input unit inputs a separation drive instruction signal.
The limited disengagement position includes a position immediately before disengagement where the retaining member shifts from the restrictive disengagement position to the complete disengagement position when the retaining member is rotated by a predetermined amount by the accompanying reverse rotation operation.
The control unit, when the input unit inputs a separation drive instruction signal, when the separation drive mode setting unit is setting a speed priority separation drive mode, to the insertion / removal drive mechanism,
(1) Based on the detection result of the detection unit, after the holding member is shifted from the insertion position to the restricted release position by the differential rotation operation, the holding member is immediately before the release by the follow reverse rotation operation. The holding member is positioned at the position immediately before the separation by the differential rotation operation after the holding member has reached the rotation angle position corresponding to the position immediately before the separation by the forward rotating rotation operation. And (2) an operation step of positioning the holding member at the position immediately before the disengagement by performing an operation with a shorter time required; and (2) after the positioning of the holding member at the position immediately before the disengagement. An imaging device that performs an operation step of moving the holding member from the position immediately before the separation to the complete separation position by performing a reverse rotation operation. In the imaging device according to claim 3 or 4,
The position immediately before the separation is shifted from the restricted separation position to the complete separation position when the holding member is rotated by α ° (however, 0 ° <α ° <180 °) by the reverse rotation operation. An imaging device that is a position to perform. The photographing apparatus according to any one of claims 1 to 5,
The input unit includes a rotary optical element detachment switch for driving the rotary optical element to detach, and a power switch for switching the power of the photographing apparatus from on to off,
The separation drive mode setting unit sets a vignetting prevention priority separation drive mode when the rotary optical element separation switch inputs a separation drive instruction signal, and speed priority separation when the power switch inputs a separation drive instruction signal. An imaging device that sets the drive mode. The photographing apparatus according to any one of claims 1 to 5,
The detachment drive mode setting unit is an imaging device including a detachment drive mode changeover switch that switches between an vignetting prevention priority detachment drive mode and a speed priority detachment drive mode. The photographing apparatus according to any one of claims 1 to 7,
The rotating optical element is a polarizing optical filter driving device.

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