JP2011169954A5 - - Google Patents

Description

Lens barrel and optical equipment

  The present invention relates to an optical apparatus including an imaging device such as a digital camera or a video camera, and an interchangeable lens.

  The optical apparatus as described above is provided with a photographing lens barrel including a plurality of lenses such as a variable power lens and a focus lens that are movable in the optical axis direction. Some photographic lens barrels are provided with a mechanism for rotating a cam ring by an actuator such as a motor and moving the lens in the optical axis direction by a cam portion formed on the cam ring. In addition, when the user rotates the manual operation ring, the cam ring connected to the operation ring via a connecting member rotates in the photographic lens barrel, and the lens is illuminated by the cam portion of the cam ring. Some are also provided with a mechanism that is moved in the axial direction.

  In such an optical apparatus, the allowable backlash between the cam ring and the fixed cylinder that rotatably supports the cam ring is generally about 10 to 30 μm. However, with the increase in the number of pixels of the image sensor that photoelectrically converts the subject image in imaging, it is necessary to reduce the allowable backlash of the cam ring relative to the fixed cylinder and improve the positional accuracy of the lens in the direction perpendicular to the optical axis. ing. Further, the cam ring and the fixed cylinder are deformed due to a manufacturing error of the cam ring and the fixed cylinder, and the deformation of the cam ring and the fixed cylinder due to the temperature change, thereby affecting the positional accuracy of the lens and the rotational load of the cam ring.

  In the optical apparatus disclosed in Patent Document 1, the manual operation ring is perpendicular to the optical axis with respect to the fixed cylinder by a plurality of balls sandwiched between the inner peripheral surface of the manual operation ring and the outer peripheral surface of the fixed cylinder. It is positioned so that it can be rotated and supported so as to be rotatable around the optical axis. Such a positioning and rotating support structure using a ball can also be used between the cam ring and the fixed cylinder.

JP 2002-365513 A

  However, similarly to the structure disclosed in Patent Document 1, in the structure in which the ball is simply sandwiched between the peripheral surface of the cam ring and the peripheral surface of the fixed cylinder, the diameter of the photographing lens barrel is equal to the diameter of the ball. It becomes large and hinders downsizing of optical equipment.

  Moreover, when the length of the cam ring in the optical axis direction is long, such as a cam ring for a variable power lens, a ball is only arranged at one place in the optical axis direction as disclosed in Patent Document 1. Then, the cam ring is easily tilted with respect to the optical axis. In order to prevent such a fall, it is necessary to extremely increase the pinching force of the ball between the cam ring and the fixed cylinder, but this increases the rotational load of the cam ring and A large driving force and operating force are required for rotation.

 The present invention improves the positional accuracy of an optical element driven by a cam ring by removing backlash between the cam ring and a fixed cylinder while suppressing an increase in radial direction and an increase in rotational load of the cam ring. Provided is an optical apparatus which can be used.

 An optical apparatus according to one aspect of the present invention includes an optical element that moves in the optical axis direction, a fixed cylinder that accommodates the optical element and guides movement of the optical element in the optical axis direction, and an inner periphery of the fixed cylinder Alternatively, a cam ring that is disposed on the outer periphery and has a cam portion that drives the optical element in the optical axis direction and rotates around the optical axis with respect to the fixed cylinder, and a first position and a second that are separated from each other in the optical axis direction And a ball that rolls while being in contact with the cam ring and the fixed cylinder. The first ball receiving surface with which the cam ring and the ball in the fixed cylinder abut at the first position is inclined with respect to the optical axis direction, and the ball at one of the cam ring and the fixed cylinder abuts at the second position. The second ball receiving surface is inclined with respect to the optical axis direction. Then, by urging the ball in the optical axis direction by the first elastic member at the first position, the cam ring is moved in the optical axis direction with respect to the fixed cylinder via the ball and the first ball receiving surface. Positioning is performed in a direction orthogonal to the optical axis direction. Furthermore, the cam ring is positioned in the direction perpendicular to the optical axis direction with respect to the fixed cylinder via the ball and the second ball receiving surface by urging the ball with the second elastic member at the second position. It is characterized by doing.

 In the present invention, at two locations (first and second positions) in the optical axis direction, balls are disposed between the cam ring and the fixed cylinder, thereby preventing the cam ring from falling with respect to the optical axis. Moreover, by energizing the ball with the elastic member, the cam ring is positioned in the optical axis direction and the direction (radial direction) perpendicular to the optical axis direction with respect to the fixed cylinder, and the play between them is removed. . For this reason, according to the present invention, it is possible to improve the positional accuracy in the optical axis direction and the radial direction of the optical element driven by the cam ring even if there is a manufacturing error or a temperature change.

 Further, since it is not necessary to increase the pinching force of the ball between the cam ring and the fixed cylinder, an increase in the rolling load of the ball and the rotation load of the cam ring can be suppressed.

 Further, since the ball receiving surfaces provided on the cam ring and the fixed cylinder are inclined with respect to the optical axis direction, it is possible to suppress the radial enlargement due to the ball being arranged between the cam ring and the fixed cylinder. it can.

Sectional drawing which shows the structure of the lens barrel of the optical instrument which is an Example of this invention. The disassembled perspective view which shows the structure of the said lens-barrel. FIG. 3 is a development view of a cam ring included in the lens barrel. The disassembled perspective view when the cam ring holding mechanism in the lens barrel is viewed from the rear side. The exploded perspective view when the said cam ring holding mechanism is seen from the front side. Sectional drawing of the rear side ball holding part of the said cam ring holding mechanism. Sectional drawing of the front side ball holding part of the said cam ring holding mechanism.

   Embodiments of the present invention will be described below with reference to the drawings.

  1 and 2 show a configuration of a lens barrel of a video camera (an optical apparatus or an imaging apparatus) that is an embodiment of the present invention.

  In the lens barrel, a zoom lens is built in as an imaging optical system composed of five convex and concave lens units in order from the subject side (left side in the figure). In the following description, the subject side is also referred to as the front side, and the imaging element side is also referred to as the rear side.

  In these drawings, in order from the subject side, L1 is a fixed first lens unit, and L2 and L3 are second and third lens units that move in the optical axis direction and perform zooming, respectively.

  L4 is a fourth lens unit that moves in a direction perpendicular to the optical axis and performs image blur correction. L5 is a fifth lens unit that moves in the optical axis direction to perform focusing. The second, third, and fifth lens units L2, L3, and L5 and a diaphragm unit 6 described later correspond to an optical element that can move in the optical axis direction.

  Reference numeral 1 denotes a front lens barrel that holds the first lens unit L1. Cam followers 1a attached to the front lens barrel 1 at intervals of 120 degrees in the circumferential direction are engaged with through-hole portions 12a formed in the fixed barrel (fixed cylinder) 12 at intervals of 120 degrees in the circumferential direction. By engaging the cam follower 1a with the through hole 12a and fitting the outer diameter portion 1b of the front lens barrel 1 and the inner diameter portion 12b of the fixed lens barrel 1, the front lens barrel 1 (first lens unit L1). Is held by the fixed lens barrel 12 while being positioned with respect to the fixed lens barrel 12.

  2 is a second moving frame that holds the second lens unit L2, and 3 is a third moving frame that holds the third lens unit L3. Reference numeral 4 denotes a shift unit that holds the fourth lens unit L4 and is capable of shifting in a direction orthogonal to the optical axis. The shift unit 4 is positioned and fixed with respect to the fixed barrel 12. Reference numeral 5 denotes a fifth moving frame that holds the fifth lens unit L5.

  The fixed barrel 12 houses therein a first lens unit L1, a second lens unit L2, a third lens unit L3, a shift unit 4, a fifth lens unit L5 and a diaphragm unit 6 which will be described later.

  Reference numeral 8 denotes an image sensor that converts a subject image (optical image) formed by the photographing optical system into an electric signal, and is composed of a CCD sensor or a CMOS sensor.

  The aperture unit 6 adjusts the amount of light that reaches the image sensor 8. Reference numeral 7 denotes an ND unit that can selectively insert four density ND filters into the optical path, and is fixed to the rear barrel 13.

  Reference numeral 10 denotes an image sensor holding frame that holds the image sensor 8 and the infrared cut / low pass filter 9. The image pickup device 8 moves in the optical axis direction together with the second and third lens units L2 and L3 and performs zooming.

  Reference numeral 11 denotes an image sensor FPC that inputs and outputs electrical signals to the image sensor 8 held by the image sensor holding frame 10.

  Reference numeral 14 denotes a rear cover, which is positioned and fixed to the rear barrel 13. Two guide bars 15 and 16 are disposed between the rear barrel 13 and the rear cover 14. The sleeve portion 10a provided on the image sensor holding frame 10 is movably engaged with the guide bar 15 and guided in the optical axis direction. Further, the U groove portion 10b provided in the image sensor holding frame 10 engages with the guide bar 16 so as to be movable in the same direction, and prevents the image sensor holding frame 10 from rotating around the guide bar 15.

  A slider (contact member) 17 is configured by joining a magnet and a friction material and fixed to the rear barrel 13. The imaging element holding frame 10 is fixed with a vibrator 18 including an electro-mechanical energy conversion element and a plate-like elastic member whose vibration is excited by the electro-mechanical energy conversion element. The elastic member of the vibrator 18 is a ferromagnetic body. When the ferromagnetic body attracts the magnet of the slider 17, it is formed at two locations in the optical axis direction on the pressure contact surface of the friction material of the slider 17 and the elastic member of the vibrator 18. The pressed surface is pressed.

  In the vibration type linear actuator constituted by the slider 17 and the vibrator 18, two frequency signals (pulse signals or alternating signals) having different phases are input to the electro-mechanical energy conversion element via a flexible wiring board (not shown). Is done. Thereby, an elliptical motion is generated on the pressure contact surface of the vibrator 18, and a driving force in the optical axis direction is generated on the pressure contact surface of the slider 17.

  The ND base 7a is fixed to the rear barrel 13, and two guide bars 19 and 20 are disposed between the rear barrel 13 and the ND base 7a. The sleeve portion 5a provided in the fifth moving frame 5 is movably engaged with the guide bar 19 and guided in the optical axis direction. Further, the U groove portion 5b provided in the fifth moving frame 5 engages with the guide bar 20 so as to be movable, and prevents rotation of the fifth moving frame 5 around the guide bar 19.

  Reference numeral 21 denotes a slider (contact member) fixed to the rear barrel 13 constituted by joining a magnet and a friction material. A vibrator (not shown) composed of an electro-mechanical energy conversion element and a plate-like elastic member whose vibration is excited by the electro-mechanical energy conversion element is fixed to the fifth moving frame 5. The elastic member of the vibrator is a ferromagnetic body. When the ferromagnetic body attracts the magnet of the slider 21, the pressure contact surface of the friction material of the slider 21 and the pressure contact formed at two places in the optical axis direction on the elastic member of the vibrator. The surface is pressed.

  In the vibration type linear actuator composed of the slider 21 and the vibrator, two frequency signals (pulse signals or alternating signals) having different phases are input to the electro-mechanical energy conversion element via a flexible wiring board (not shown). The Thereby, an elliptical motion is generated on the pressure contact surface of the vibrator, and a driving force in the optical axis direction is generated on the pressure contact surface of the slider 21.

  Reference numeral 22 denotes a cam ring, which is disposed on the inner periphery of the fixed barrel 12 so as to be rotatable around the optical axis by a cam ring holding mechanism described later. As shown in FIG. 3, the cam ring 22 includes a first cam groove portion (cam portion) 22a for driving the second moving frame 2 (second lens unit L2) in the optical axis direction, and a third moving frame 3 (first moving frame 3). A second cam groove portion (cam portion) 22b for driving the three lens unit L3) in the optical axis direction is formed. The cam ring 22 is also formed with a third cam groove 22c that drives the aperture unit 6 in the optical axis direction.

  Cam followers 2a, 3a, 6a provided at intervals of 120 degrees in the circumferential direction on the second moving frame 2, the third moving frame 3, and the aperture unit 6 are engaged with these cam grooves 22a, 22b, 22c, respectively. . The fixed barrel 12 is formed with guide groove portions 12c and 12d extending in the optical axis direction at intervals of 120 degrees in the circumferential direction. The cam follower 2a is engaged with the guide groove 12c, and the cam followers 3a and 6a are engaged with the guide groove 12d. The second moving frame 2, the third moving frame 3, and the aperture unit 6 are arranged in the direction of the optical axis while the cam followers 2a, 3a, 6a are engaged with the guide groove portions 12c, 12d to prevent rotation around the optical axis. Guided.

  When the cam ring 22 rotates around the optical axis with respect to the fixed barrel 12 during zooming, the second moving frame 2, the third moving frame 3 and the cam followers 2a, 3a, 6a of the aperture unit 6 that are prevented from rotating are The driving force in the optical axis direction is received from the first to third cam groove portions 22a to 22c. Thereby, the 2nd moving frame 2, the 3rd moving frame 3, and the aperture unit 6 move to an optical axis direction.

  Reference numerals 23 and 24 respectively denote a zoom ring and a focus ring as operation members that are manually rotated by the user. The zoom ring 23 is disposed between the zoom ring holding cylinder 25 and the intermediate lens barrel 26 in the optical axis direction, and is held rotatably around the optical axis on the outer periphery of the zoom ring holding cylinder 25. The focus ring 24 is disposed between the focus ring holding cylinder 27 and the intermediate lens barrel 26 in the optical axis direction, and is held rotatably around the optical axis on the outer periphery of the focus ring holding cylinder 27.

  A rotation sensor (not shown) for detecting the amount of rotation of the rings 23 and 24 is provided on the inner periphery of the zoom ring 23 and the focus ring 24. By using output signals corresponding to the rotation amounts of the zoom ring 23 and the focus ring 24 from the rotation sensor, the rotation positions of the zoom ring 23 and the focus ring 24 can be detected.

  Next, a cam ring holding mechanism that holds the cam ring 22 will be described with reference to FIGS. 4 and 5 are exploded views of the cam ring holding mechanism as viewed from the rear side and the front side, respectively. FIGS. 6 and 7 show cross sections of the rear portion and the front portion of the cam ring holding mechanism, respectively.

  A slider (contact member) 28 is configured by joining a magnet and a friction material and fixed to the cam ring 22. On the cam ring retainer plate 29, vibrators 30 constituted by electro-mechanical energy conversion elements and plate-like elastic members excited by the electro-mechanical energy conversion elements are fixed at intervals of 120 ° in the circumferential direction. ing. The elastic member of the vibrator 30 is a ferromagnetic body. When the ferromagnetic body attracts the magnet of the slider 28, the cam ring 22 is rotated at two locations in the pressure contact surface of the friction material of the slider 28 and the elastic member of the vibrator 30. The pressure contact surface formed on the surface is pressed.

  In the vibration type linear actuator constituted by the slider 28 and the vibrator 30, two frequency signals (pulse signals or alternating signals) having different phases are input to the electro-mechanical energy conversion element via a flexible wiring board (not shown). The As a result, an elliptical motion is generated on the pressure contact surface of the vibrator 30, and a driving force is generated on the pressure contact surface of the slider 28 in the tangential direction of the rotation direction of the cam ring 22. Then, the cam ring 22 is smoothly rotated around the optical axis by synchronously controlling the three vibrators 30 arranged at intervals of 120 ° in the circumferential direction.

  As shown in FIG. 4, a rotation sensor 31 for detecting the amount of rotation of the cam ring 22 is provided on the inner periphery of the cam ring 22. By using an output signal corresponding to the amount of rotation of the cam ring 22 from the rotation sensor 31, the rotational position of the cam ring 22 can be detected.

  As shown in FIG. 6, rear ball receiving surfaces 22 d and 22 e extending in the circumferential direction of the cam ring 22 are formed on the front side and the rear side in the rear part (first position) of the cam ring 22. The rear ball receiving surfaces 22d and 22e are formed so as to be inclined by 45 degrees with respect to the optical axis direction and 90 degrees with respect to each other in the cross section (circumferential view cross section) of FIG. A rear ball receiving surface 12 e extending in the circumferential direction of the fixed barrel 12 is also formed on the front side of the rear portion of the fixed barrel 12. In the cross section of FIG. 6, the rear ball receiving surface 12e is inclined by 45 degrees with respect to the optical axis direction, forms 90 degrees with the rear ball receiving surface 22d, and is formed to face the rear ball receiving surface 22e. .

  The rear ball 32 is assembled so as to contact the rear ball receiving surfaces 22d, 22e, and 12e. Reference numeral 33 denotes a rear ball retainer, which holds a plurality of rear balls 32 arranged in the circumferential direction so as to be able to rotate and revolve, that is, to be able to roll while keeping their circumferential intervals constant.

  Reference numeral 34 denotes a rear ball pressing member, and a rear ball pressing surface 34 a extending in the circumferential direction is brought into contact with the rear ball 32. The rear ball pressing surface 34a is inclined 45 degrees with respect to the optical axis direction in the cross section of FIG. 6, forms 90 degrees with the rear ball receiving surfaces 22e and 12e, and faces the rear ball receiving surface 22d.

  Reference numeral 35 denotes a rear ball cover, which is positioned and held with respect to the fixed barrel 12 by engaging a screw portion 35a formed on the outer peripheral portion thereof with a screw portion 12f formed on the fixed barrel 12. Yes.

  Reference numeral 36 denotes a rear leaf spring (first elastic member), which is disposed between the rear ball cover 35 and the rear ball pressing member 34 and biases the rear ball pressing member 34 forward. The rear ball pressing member 34 presses the rear ball 32 against the rear ball receiving surfaces 22d, 22e, and 12e by the rear ball pressing surface 34a, and the position of the rear ball cover 35 and the rear ball 32 is variable in the radial direction. Are arranged in a space A surrounded by.

  With the above configuration, the rear ball 32 abuts the rear ball receiving surfaces 22d, 22e, 12e and the rear ball pressing surface 34a at four locations, and the rear ball receiving surfaces 22d, 22e, 12e are urged by the urging force from the rear leaf spring 36. And the rear ball pressing surface 34a.

  The rear ball receiving surfaces (first ball receiving surfaces) 22d and 12e are inclined 45 degrees with respect to the optical axis direction. Therefore, the urging force in the optical axis direction of the rear leaf spring 36 causes the cam ring 22 to move in the optical axis direction and the radial direction (direction orthogonal to the optical axis direction) with respect to the fixed barrel 12 via the rear ball 32. Acts as a positioning force. Therefore, the rear portion of the cam ring 22 can be held in a state of being positioned in the optical axis direction and the radial direction with respect to the fixed barrel 12.

  When the cam ring 22 is rotated, the rear ball 32 rolls while contacting the rear ball receiving surfaces 22d, 22e, 12e and the rear ball pressing surface 34a. Thereby, the cam ring 22 can be smoothly rotated with respect to the fixed barrel 12.

  The urging force of the rear leaf spring 36 includes the weight of the cam ring 22, the second and third moving frames 2 and 3 including the second and third lens units L2 and L3, and the aperture unit 6, and the front leaf spring described later. It is set to a strength equal to or greater than the sum of the urging force in the optical axis direction. However, the rolling load of the rear ball 32 is determined so as to be appropriate.

  As shown in FIG. 7, a front ball receiving surface 22 f extending in the circumferential direction of the cam ring 22 is formed at a front portion (second position) separated from the rear portion of the cam ring 22 in the optical axis direction. The front ball receiving surface 22f is inclined 45 degrees with respect to the optical axis direction in the cross section (circumferential cross section) of FIG. A front ball receiving surface 12 g extending in the circumferential direction of the fixed barrel 12 is also formed on the inner periphery of the front portion of the fixed barrel 12. The front ball receiving surface 12g is formed parallel to the optical axis direction in the cross section of FIG. 7, and forms 45 degrees with the front ball receiving surface 22f of the cam ring 22.

  The front ball 37 is incorporated so as to contact the front ball receiving surfaces 22f and 12g. Reference numeral 38 denotes a front ball retainer, which holds a plurality of front balls 37 arranged in the circumferential direction so as to be able to rotate and revolve, that is, to be able to roll, while maintaining their circumferential intervals constant.

  Reference numeral 39 denotes a front ball pressing member, and a front ball pressing surface 39 a extending in the circumferential direction is brought into contact with the front ball 37. The front ball pressing surface 39a is inclined by 45 degrees with respect to the optical axis direction and the front ball receiving surface 12g of the fixed barrel 12 in the cross section of FIG. 7, and the front ball receiving surfaces 22f and 90 of the cam ring 22 are inclined. Make a degree.

  A front ball cover 40 is positioned and held with respect to the fixed lens barrel 12 by engaging a screw portion 40a formed on the outer periphery of the front ball cover with a screw portion 12h formed on the fixed lens barrel 12. ing.

  A front leaf spring (second elastic member) 41 is disposed between the front ball cover 40 and the front ball pressing member 39 and biases the front ball pressing member 39 rearward. While the front ball pressing member 39 presses the front ball 37 against the front ball receiving surfaces 22f and 12g by the front ball pressing surface 39a, the front ball cover 40 and the front ball cover 40 in a state where the radial position is variable. It is arranged in a space B surrounded by the front ball 37.

  With the above configuration, the front ball 37 abuts against the front ball receiving surfaces 22f and 12g and the front ball pressing surface 39a at three locations, and the front ball receiving surface 22f, 12g and the front ball pressing surface 39a.

  A front ball receiving surface (second ball receiving surface) 22f of the cam ring 22 is inclined 45 degrees with respect to the optical axis direction. For this reason, the biasing force in the optical axis direction of the front leaf spring 41 acts as a force for positioning the cam ring 22 with respect to the fixed barrel 12 in the radial direction via the front ball 37. Therefore, the front portion of the cam ring 22 can be held in a state of being positioned in the radial direction with respect to the fixed barrel 12. The front ball receiving surface 12g of the fixed barrel 12 is formed in parallel to the optical axis direction so as not to hinder positioning in the optical axis direction at the rear part.

  When the cam ring 22 is rotated, the front ball 37 rolls while contacting the front ball receiving surfaces 22f and 12g and the front ball pressing surface 39a. Thereby, the cam ring 22 can be smoothly rotated with respect to the fixed barrel 12.

  The biasing force of the front leaf spring 41 is set to a strength greater than the weight of the cam ring 22. However, it is determined so that the rolling load of the front ball 37 is appropriate.

  According to this embodiment, the cam ring 22 is positioned in the radial direction with respect to the fixed barrel 12 at two locations in the optical axis direction, and the cam ring 22 is positioned with respect to the fixed barrel 12 at one location. Position in the direction. Moreover, the positioning is performed by pressing the balls 32 and 37 against the cam ring 22 and the fixed barrel 12 by the urging force of the leaf springs 36 and 41. Accordingly, the cam ring 22 can be accurately positioned with respect to the fixed barrel 12 in the optical axis direction and the radial direction regardless of manufacturing errors and temperature changes, while preventing the cam ring 22 from being tilted with respect to the optical axis. Therefore, the positional accuracy in the optical axis direction and radial direction of the second and third lens units L2 and L3 and the diaphragm unit 6 driven in the optical axis direction by the cam ring 22 can be improved.

  Further, since the radial positioning with respect to the fixed barrel 12 is performed at two locations in the optical axis direction of the cam ring 22, it is not necessary to increase the urging force of the leaf springs 36 and 41 so much. Therefore, an increase in the rolling load of the balls 32 and 37 and the rotational load of the cam ring 22 can be avoided.

  Further, since the ball receiving surfaces 22d, 22e, 22f, 12e provided on the cam ring 22 and the fixed barrel 12 are inclined with respect to the optical axis direction, the ball 32 is interposed between the cam ring 22 and the fixed barrel 12. , 37 can be prevented from increasing in size in the radial direction of the lens barrel.

  In the above embodiment, the front ball receiving surface 12g formed on the fixed lens barrel 12 is a surface parallel to the optical axis direction, and the front ball receiving surface 22f formed on the cam ring 22 is in the optical axis direction. The case where the surface is inclined by 45 degrees has been described. However, a front ball receiving surface inclined by 45 degrees with respect to the optical axis direction may be formed on the fixed barrel, and a front ball receiving surface parallel to the optical axis direction may be formed on the cam ring. In this case, the front leaf spring does not need to generate an urging force in the optical axis direction against the cam ring, and only needs to generate a urging force in the radial direction. Thereby, it is possible to avoid the biasing force of the front leaf spring from affecting the biasing by the rear leaf spring.

  Each embodiment described above is only a representative example, and various modifications and changes can be made to each embodiment in carrying out the present invention.

  For example, in the above embodiment, the front and rear ball receiving surfaces and the ball pressing surface are formed so as to be inclined 45 degrees with respect to the optical axis direction (90 degrees with the adjacent ball receiving surface). However, the inclination angle with respect to the optical axis direction is not necessarily 45 degrees.

  In the above-described embodiment, the case where the cam ring 22 is disposed on the inner periphery of the fixed barrel 12 has been described. However, the cam ring may be disposed on the outer periphery of the fixed barrel.

  In the above-described embodiments, the camera in which the image sensor and the photographing lens barrel are integrally provided has been described. However, the present invention is not limited to an interchangeable lens or a photographing lens barrel as a component unit integrally provided in the camera. It is also possible to use it for the optical apparatus.

  It is possible to provide an optical device such as a camera or an interchangeable lens having a high positional accuracy of a movable lens driven by a cam ring.

12 fixed barrel 22 cam ring 32, 37 ball 36, 41 leaf spring

Claims (4)

An optical element moving in the direction of the optical axis;
A fixed cylinder that houses the optical element and guides movement of the optical element in the optical axis direction;
A cam ring disposed on the inner periphery or outer periphery of the fixed cylinder, having a cam portion for driving the optical element in the optical axis direction, and rotating around the optical axis with respect to the fixed cylinder;
A ball that is disposed between the cam ring and the fixed cylinder at a first position and a second position that are separated from each other in the optical axis direction, and that rolls while contacting the cam ring and the fixed cylinder; Have
In the first position, the cam ring and the first ball receiving surface with which the ball contacts the fixed cylinder are inclined with respect to the optical axis direction, and in the second position, the cam ring and the fixed cylinder A second ball receiving surface on which one of the balls abuts is inclined with respect to the optical axis direction,
In the first position, the cam ring is biased to the fixed cylinder via the ball and the first ball receiving surface by urging the ball in the optical axis direction by a first elastic member. Positioning in the optical axis direction and the direction orthogonal to the optical axis direction,
In the second position, the cam ring is urged in the optical axis direction with respect to the fixed cylinder via the ball and the second ball receiving surface by urging the ball by a second elastic member. An optical apparatus characterized by positioning in a direction orthogonal to each other. The optical apparatus according to claim 1, wherein the first elastic member and the second elastic member are leaf springs. An optical element moving in the direction of the optical axis;
A fixed cylinder that houses the optical element and guides movement of the optical element in the optical axis direction;
A cam ring disposed on the inner periphery or outer periphery of the fixed cylinder, having a cam portion for driving the optical element in the optical axis direction, and rotating around the optical axis with respect to the fixed cylinder;
A ball that is disposed between the cam ring and the fixed cylinder at a first position and a second position that are separated from each other in the optical axis direction, and that rolls while contacting the cam ring and the fixed cylinder; Have
In the first position, the cam ring and the first ball receiving surface with which the ball contacts the fixed cylinder are inclined with respect to the optical axis direction, and in the second position, the cam ring and the fixed cylinder A second ball receiving surface on which one of the balls abuts is inclined with respect to the optical axis direction,
In the first position, the cam ring is biased to the fixed cylinder via the ball and the first ball receiving surface by urging the ball in the optical axis direction by a first elastic member. Positioning in the optical axis direction and the direction orthogonal to the optical axis direction,
In the second position, the cam ring is urged in the optical axis direction with respect to the fixed cylinder via the ball and the second ball receiving surface by urging the ball by a second elastic member. A lens barrel characterized by being positioned in a perpendicular direction. A lens barrel according to claim 3;
An optical device comprising a camera to which the lens barrel can be attached and detached.