JP5355120B2 - Optical equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a lens-holding member from changing its position and an angle at which it tilts, when it is fixed to a support cylinder using a fixing screw. <P>SOLUTION: Optical equipment has a lens-holding member 207 which holds a lens L1; a support cylinder 205, which supports the lens-holding member and has a peripheral wall in which a fixing groove part 205F is formed; a screw base member 228, which has a screw hole 228B and is mounted on the lens-holding member, rotatable about the axis of the screw hole; and a fixing screw 229 which is screwed into the screw hole through the fixing groove part and whose head part pinches the peripheral wall of the supporting cylinder, together with the screw base member to fix the lens-holding member to the supporting cylinder. The screw base member has a projection section 228D, which contacts the inner surface of the fixing groove part to prevent the screw base member from rotating and moving due to the screwing of the fixing screw. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to an optical apparatus such as a digital still camera, a video camera, and an interchangeable lens, and more particularly to an optical apparatus that fixes a lens holding member that holds a lens to a support tube using a screw.

  A lens system mounted on an optical device may include a lens that moves in the optical axis direction and performs zooming and focus adjustment, as well as a lens that does not move during zooming and focus adjustment (hereinafter referred to as a fixed lens). Many. For example, in a so-called inner focus (or rear focus) zoom lens system, the lens closest to the object side is a fixed lens, and the zoom lens or focus lens arranged closer to the image plane is moved in the optical axis direction. Adjust zoom and focus. In a general optical apparatus, the fixed lens is held by a lens holding member, and the lens holding member is supported by a support cylinder that forms a housing of the lens barrel.

  To improve the optical performance of the lens system, adjust the position of the lens holding member in the optical axis direction with respect to the support tube to adjust the focus at infinity or the nearest end, or change the tilt angle of the lens holding member with respect to the support tube. It is necessary to adjust and align the optical axis with other lenses.

In the optical apparatus disclosed in Patent Document 1, an eccentric roller that engages with a cam groove formed on a peripheral wall of a support cylinder is inserted into a roller seat formed on a lens holding member that holds a fixed lens, and a screw is used. Fix it. By moving the eccentric roller along the cam groove, the position of the lens holding member with respect to the support tube in the optical axis direction is adjusted, and by rotating the eccentric roller, the tilt angle of the lens holding member with respect to the support tube is adjusted. .
JP 2005-227400 A

  In the lens barrel disclosed in Patent Document 1, after the adjustment of the position and the tilt angle of the lens holding member is completed, the lens holding member is formed at three locations in the circumferential direction of the lens holding member through the fixing groove formed on the peripheral wall of the support cylinder. Tighten the fixing screw. The lens holding member is integrally fixed to the support cylinder by sandwiching the peripheral wall of the support cylinder between the head of the fixing screw and the outer peripheral surface of the lens holding member.

  However, in such a fixing method, the lens holding member and the support tube are distorted by tightening the fixing screw. Further, the lens holding member rotates with respect to the support tube as the fixing screw rotates. As a result, the position and tilt angle of the lens holding member (fixed lens) may change.

  The present invention provides an optical apparatus in which the position of the lens holding member and the tilt angle are not changed when the lens holding member is fixed to the support cylinder using a fixing screw.

An optical apparatus according to an aspect of the present invention includes a lens holding member that holds a lens, an adjustment groove that supports the lens holding member and engages a fixing groove and a follower provided on the lens holding member. a support tube having peripheral walls, a threaded bore, a threaded base member which is attach to the lens holding member, a screw tightened to the anchoring groove in the screw hole, its head screw base member And a fixing screw for fixing the lens holding member to the support cylinder by sandwiching the peripheral wall of the support cylinder between them. It is possible to adjust the position in the optical axis direction of the lens holding member relative to the support tube by moving the follower along the adjustment groove, and to adjust the tilt angle of the lens holding member relative to the support tube by eccentric rotation of the follower. The screw base member has a width smaller than the width of the fixing groove, protrudes into the fixing groove, and has a protrusion that prevents rotation of the screw base member by contacting the inner surface of the fixing groove. And is attached to the lens holding member so as to be rotatable about the axis of the screw hole as the fixing screw is tightened until the protrusion comes into contact with the inner surface of the fixing groove. To do.

In the present invention , by adjusting the width of the protrusion of the screw base member to be smaller than the width of the fixing groove, in addition to adjusting the position in the optical axis direction of the lens holding member with respect to the support tube by moving the follower along the adjusting groove. Thus, the tilt angle of the lens holding member with respect to the support tube can be adjusted by eccentric rotation of the follower. When the fixing screw is tightened into the screw base member , the protrusion of the screw base member comes into contact with the inner surface of the fixing groove, thereby preventing the screw base member from rotating relative to the lens holding member. For this reason, the lens holding member can be fixed to the support cylinder by sandwiching the peripheral wall of the support cylinder between the head of the fixing screw and the screw base member. In addition, the screw base member is attached to the lens holding member so as to be rotatable around the axis of the screw hole as the fixing screw is tightened until the protrusion comes into contact with the inner surface of the fixing groove . Therefore, the rotational force generated by tightening the fixing screw is not transmitted to the lens holding member. Accordingly, it is possible to avoid changes in the position and tilt angle of the lens holding member due to tightening of the fixing screw.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows a schematic configuration of an interchangeable lens as an optical apparatus according to an embodiment of the present invention and a single-lens reflex digital still camera (imaging device) to which the interchangeable lens is attached. Reference numeral 1 denotes a single-lens reflex digital still camera (hereinafter referred to as a camera), and reference numeral 2 denotes a zoom optical system provided in the interchangeable lens 200. The zoom optical system 2 has a plurality of lens units described later. An anti-vibration driving unit 3 drives the anti-vibration lens unit 12 included in the zoom optical system 2 in a direction perpendicular to the optical axis 4 of the zoom optical system 2. Reference numeral 5 denotes a lens barrel that accommodates the zoom optical system 2. The lens barrel 5 and the zoom optical system 2 constitute an interchangeable lens 200 as a zoom lens device. The interchangeable lens 200 can be attached to and detached from the camera 1.

  In the camera 1, reference numeral 6 denotes an image sensor such as a CCD sensor or a CMOS sensor that photoelectrically converts a subject image formed by the zoom optical system 2. Reference numeral 7 denotes a memory for storing image data generated based on the output from the image sensor 6. Reference numeral 8 denotes a shake sensor that detects camera shake such as camera shake, and reference numeral 9 denotes a focus drive unit that drives a focus lens unit included in the zoom optical system 2.

  Reference numeral 10 denotes a power source of the camera 1 (and the interchangeable lens 200), and 11 denotes a release button. Reference numeral 13 denotes a quick return mirror, and reference numeral 14 denotes a finder optical system.

  FIG. 2 shows an electrical configuration of the camera 1 and the interchangeable lens 200. The camera 1 has an imaging system, an image processing system, a recording / reproducing system, and a control system.

  The imaging system is composed of an imaging element 6. The image processing system includes an A / D converter 20 and an image processing circuit 21. The recording / reproducing system includes a recording processing circuit 23 and a memory 24. The control system includes a camera system control circuit 25, an AF sensor 26, an AE sensor 27, a shake sensor 8, and an operation detection circuit 29. The interchangeable lens includes a lens system control circuit 30.

  The image processing circuit 21 performs various processes such as white balance, gamma correction, and interpolation calculation on the output signal received from the image sensor 6 via the A / D converter 20 to generate image data. The recording processing circuit 23 performs recording processing of image data in the memory 24 and generates an image to be output to the display unit 22 configured by a liquid crystal monitor or the like.

  The operation detection circuit 29 detects an operation of an operation member such as the release button 11 and sends an operation detection signal to the camera system control circuit 25. The camera system control circuit 25 controls each part in the camera 1 and the interchangeable lens according to the operation detection signal.

  The AF sensor 26 detects the focus state of the interchangeable lens. The AE sensor 27 detects the luminance of the subject. The shake sensor 8 detects camera shake. The camera system control circuit 25 outputs to the lens system control circuit 30 signals for controlling the focusing, aperture, and image stabilization operations based on signals from the AF sensor 26, the AE sensor 27, and the shake sensor 8. The lens system control circuit 30 controls the focus drive unit 9, the aperture drive unit (not shown), and the image stabilization drive unit 3 in accordance with a signal from the camera system control circuit 25.

  Next, the configuration of the interchangeable lens 200 will be described with reference to FIGS. 3 and 4. FIG. 3 shows a cross-sectional structure when the interchangeable lens 200 is cut along a plane passing through the optical axis 4. FIG. 4 shows a part of the interchangeable lens 200 in an exploded manner.

  The interchangeable lens 200 has a mount 201 for detachably mounting on the camera 1. The mount 201 is provided with a connector for communication between the camera 1 and the interchangeable lens 200. The mount 201 is attached to the base cylinder 203 with screws. An intermediate cylinder 204 is fixed to the base cylinder 203 with screws.

  The intermediate cylinder 204 is attached to the guide cylinder 205 with screws. An outer ring 206 is attached to the intermediate cylinder 204 with screws. The guide cylinder 205 (and the intermediate cylinder 204) corresponds to a fixed cylinder that does not move during zooming and focus adjustment.

  A first lens holding cylinder (lens holding member) 207 holding a first lens unit (fixed lens) L1 is supported on the most object side (left side in the drawing) of the guide cylinder 205.

  The first lens unit L1 held by the first lens holding cylinder 207 is disposed on the object side (most object side among the plurality of lens units) with respect to a second lens unit (focus lens unit) L2 described later. It does not move during zooming and focusing.

  However, an eccentric cam follower 210 is attached to the first lens holding cylinder 207 with a screw. As shown in FIG. 3, the eccentric cam follower 210 includes a shaft portion 210A that is inserted into a hole formed in the outer peripheral surface of the first lens holding cylinder 207, and an eccentric follower portion 210B that is eccentric with respect to the shaft portion 210A. Have The eccentric follower portion 210B is engaged with a position adjusting cam groove (adjusting groove) 205B formed in the guide tube (supporting tube) 205.

  When the interchangeable lens 200 is assembled, when the first lens holding cylinder 207 is rotated around the optical axis, the eccentric cam follower 210 moves along the position adjusting cam groove 205B. Thereby, the position in the optical axis direction of the first lens holding cylinder 207 with respect to the guide cylinder 205 can be adjusted.

  When the eccentric cam follower 210 is rotated about the axis of the shaft portion 210A, the guide tube 205 (that is, another lens) of the first lens holding tube 207 is caused by the eccentric rotation of the eccentric follower portion 210B in the position adjusting cam groove portion 205B. The tilt angle with respect to the optical axis of the unit changes. Thereby, the tilt angle of the first lens holding cylinder 207 with respect to the guide cylinder 205 can be adjusted. A method of fixing the first lens holding cylinder 207 to the guide cylinder 205 will be described later.

  A main cam cylinder (rotating cylinder) 208 is arranged inside the guide cylinder 205. A cam follower (not shown) is attached to the main cam cylinder 208 with screws. The cam follower is engaged with a groove 205 </ b> A formed to extend in the circumferential direction on the inner periphery of the guide cylinder 205. Therefore, the main cam cylinder 208 does not move in the optical axis direction with respect to the guide cylinder 205 (that is, at a fixed position in the optical axis direction) and can rotate around the optical axis. The main cam cylinder 208 is formed with a fourth cam groove 208B.

  A sub cam cylinder (cam cylinder) 209 is disposed inside the main cam cylinder 208. A cam follower (second cam follower) C shown in FIG. 4 is attached to the sub cam cylinder 209 with screws. As shown in FIG. 4, the cam follower C includes a rectilinear groove portion (second rectilinear guide portion) 208A provided in the main cam cylinder 208 so as to extend in the optical axis direction, and a sub cam groove portion (second cam) provided in the guide cylinder 205. Part) 205D. Therefore, when the main cam cylinder 208 rotates, the sub cam cylinder 209 rotates around the optical axis together with the main cam cylinder 208 and moves in the optical axis direction with respect to the main cam cylinder 208. The sub cam cylinder 209 is provided with a focus cam groove portion (first cam portion) 209B.

  Inside the sub cam cylinder 209, a third lens rectilinear guide cylinder (second rectilinear guide cylinder) 214 is arranged. As shown in FIG. 4, the convex portion 211A of the second lens rectilinear guide tube 211 and the groove portion 209A of the sub cam tube 209 are bayonet-coupled. Therefore, the second lens rectilinear guide tube 211 can move in the optical axis direction together with the sub cam tube 209 and can rotate around the optical axis with respect to the sub cam tube 209.

  As shown in FIG. 4, the second lens rectilinear guide tube 211 is provided with a rectilinear groove portion (first rectilinear guide portion) 211B and a focus key groove portion 211C that extend in the optical axis direction. A focus key 2A2 of a focus drive unit (focus drive mechanism) 2A, which will be described later, engages with the focus key groove 211C in the direction around the optical axis.

  Inside the second lens rectilinear guide tube 211, a second lens holding tube (focus lens holding tube) 212 holding the second lens unit L2 that is a focus lens unit is disposed. A cam follower (first cam follower) 213 is attached to the outer periphery of the second lens holding cylinder 212 with screws. The cam follower 213 is engaged with a focus cam groove portion 209 </ b> B provided in the sub cam cylinder 209 and a rectilinear groove section 211 </ b> B provided in the second lens rectilinear guide cylinder 211.

  Inside the sub cam cylinder 209, a third lens rectilinear guide cylinder (second rectilinear guide cylinder) 214 is arranged. A groove 214A formed so as to extend in the circumferential direction on the outer periphery of the third lens rectilinear guide tube 214 and a convex portion 209B formed on the inner periphery of the sub cam tube 209 are bayonet-coupled. Thus, the third lens rectilinear guide tube 214 can move in the optical axis direction together with the sub cam tube 209 and can rotate around the optical axis with respect to the sub cam tube 209.

  The third lens rectilinear guide tube 214 has a rectilinear groove portion (third rectilinear guide portion) 214B and a rectilinear guide key groove portion 214C extending in the optical axis direction. A rectilinear guide key (rotation prevention member) 216 engages with the rectilinear guide key groove 214C in the direction around the optical axis.

  Inside the third lens rectilinear guide tube 214, a third lens holding tube 215 that holds the third lens unit L3 adjacent to the second lens unit L2 in the optical axis direction (image side) is disposed. .

  A cam follower (third cam follower) E is attached to the outer periphery of the third lens holding cylinder (magnifying lens holding cylinder) 215 with screws. The cam follower E is engaged with a zoom cam groove part (third cam part) 209D provided in the sub cam cylinder 209 and a rectilinear groove part 214B provided in the third lens rectilinear guide cylinder 214.

  Here, the sub cam cylinder 209 has a first cylinder part 209E on the object side, and a second cylinder part 209F having a smaller inner and outer diameter than the first cylinder part 209E on the image side. The second lens unit L2 and the second lens holding cylinder 212 that holds the second lens unit L2 are disposed inside the first cylinder portion 209E. The third lens unit L3 and the third lens holding cylinder 215 that holds the third lens unit L3 are disposed inside the second cylinder portion 209F.

  A straight guide key 216 is fixed to the guide tube 205. As described above, the rectilinear guide key 216 is engaged with the rectilinear guide key groove 214C of the third lens rectilinear guide tube 214.

  A cam follower 218 is attached to the outer periphery of the fourth lens holding cylinder 217 holding the fourth lens unit L4 with screws. As shown in FIG. 4, the cam follower 218 is engaged with a fourth cam groove 208 </ b> B provided on the main cam cylinder 208 and a rectilinear groove 205 </ b> E provided on the inner periphery of the guide cylinder 205.

  A zoom operation ring (zoom operation member) 219, a gear ring 220 attached to the zoom operation ring 219 with a screw, and a zoom lever, which will be described later, are attached to the outside of the intermediate cylinder 204, and rotate on the outer periphery of the intermediate cylinder 204. Possible gear rings 221 are arranged. The zoom operation ring 219, the gear ring 220, and the gear ring 221 are rotatable around the optical axis at a fixed position in the optical axis direction with respect to the intermediate cylinder 204. Further, a rolling gear unit 222 is disposed between the gear ring 220 and the gear ring 221, and the gear unit 222 is coupled to the intermediate cylinder 204 with a screw.

  One end of the zoom lever 223 is attached to the gear ring 221 with a screw. The other end of the zoom lever 223 is engaged with the main cam cylinder 208 in the direction around the optical axis.

  A focus operation ring (focus operation member) 224 is disposed outside the guide tube 205. A cam follower 205G attached to the outer periphery of the guide tube 205 with a screw is engaged with a groove 224A provided on the inner periphery of the focus operation ring 224. For this reason, the focus operation ring 224 can rotate around the optical axis at a fixed position in the optical axis direction outside the guide tube 205.

  The focus operation ring 224 is coupled to the fixed position rotation ring 2A1 in the focus drive unit 2A. For this reason, the rotational force of the focus operation ring 224 can be transmitted to the focus drive unit 2A.

  The focus drive unit 2A incorporates a differential operation mechanism. The rotational force output from the differential operation mechanism is transmitted to the second lens rectilinear guide tube 211 via the focus key 2A2 engaged with the focus key groove 211C of the second lens rectilinear guide tube 211, and rotates it.

  On the image side of the fourth lens holding cylinder 217, an electric aperture unit 2C is disposed. A fifth lens holding cylinder 225 that holds the fifth lens unit L5 is disposed on the image side of the electric aperture unit 2C. The fifth lens holding cylinder 225 is disposed inside the intermediate cylinder 204. A follower (not shown) is attached to the outer periphery of the fifth lens holding cylinder 225, and the follower is engaged with a hole (not shown) formed in the inner periphery of the intermediate cylinder 204. For this reason, the fifth lens holding cylinder 225 is held at a fixed position in the optical axis direction with respect to the intermediate cylinder 204.

  The sixth lens unit L6 corresponds to the anti-vibration lens unit 12 shown in FIGS. The anti-vibration unit 2B includes a sixth lens holding cylinder 226 that holds the sixth lens unit L6, and two sets for moving the sixth lens holding cylinder 226 in two directions orthogonal to the optical axis and orthogonal to each other. And an anti-vibration actuator (magnet and coil). Further, the image stabilization unit 2B includes a position detection element that detects the position of the sixth lens holding cylinder 226, and a drive control board that controls the image stabilization actuator using a signal from the position detection element. The anti-vibration driving unit 3 in FIGS. 1 and 2 is configured by the anti-vibration actuator, the position detection element, and the drive control board.

  A cam follower (not shown) that engages with a hole (not shown) formed on the inner periphery of the intermediate cylinder 204 is attached to the outer periphery of the vibration isolation unit 2B. Accordingly, the image stabilization unit 2B is held at a fixed position in the optical axis direction with respect to the intermediate tube 204.

  A seventh lens holding cylinder 227 holding a seventh lens unit L7, which is the most image side lens unit, is fixed to the image side end of the intermediate cylinder 204 with a screw. An angular velocity sensor (gyro sensor) corresponding to the shake sensor 8 shown in FIGS. 1 and 2 is attached to the seventh lens holding cylinder 227. The seventh lens holding cylinder 227 is attached with two control boards on which the lens system control circuit 30 shown in FIG. 2 is configured.

  Next, an operation when the zoom operation ring 219 is operated at the time of zooming in the interchangeable lens 200 configured as described above will be described. In the following description, rotating around the optical axis is simply referred to as “rotating”, and moving in the optical axis direction is referred to as “going straight”.

  When the zoom operation ring 219 is rotated, the gear ring 220 is rotated and the gear ring 221 is rotated via the gear unit 222. The rotational force of the gear ring 221 is transmitted to the main cam cylinder 208 via the zoom lever 223 and rotates it. The rotation direction of the main cam cylinder 208 is opposite to the rotation direction of the zoom operation ring 219. As described above, the main cam cylinder 208 rotates with respect to the guide cylinder 205 at a fixed position in the optical axis direction.

  When the main cam cylinder 208 rotates, the sub cam cylinder 209 having the cam follower C engaged with the rectilinear groove portion 208 </ b> A of the main cam cylinder 208 rotates the same amount as the main cam cylinder 208. Since the cam follower C is also engaged with the sub cam groove 205 </ b> D of the guide cylinder 205, the sub cam cylinder 209 advances straight with respect to the main cam cylinder 208. That is, the sub cam cylinder 209 advances straight with respect to the main cam cylinder 208 while rotating.

  A rotational force acts on the second lens rectilinear guide cylinder 211 that is bayonet-coupled to the sub cam cylinder 209 due to friction of the bayonet-coupled portion. However, the focus key 2A2 of the focus drive unit 2A is engaged with the focus key groove 211C of the second lens rectilinear guide tube 211. The focus key 2A2 is held so as not to rotate by a friction holding force (a friction holding force larger than the friction of the bayonet coupling portion) in the differential operation mechanism of the focus drive unit 2A. For this reason, the rotation of the second lens rectilinear guide tube 211 is prevented.

  As described above, the second lens holding cylinder 212 has the cam follower 213 engaged with the focus cam groove 209B of the sub cam cylinder 209 and the rectilinear groove 211B of the second lens rectilinear guide cylinder 211. Therefore, when the sub cam cylinder 209 rotates while moving straight, the second lens holding cylinder 212 moves straight with respect to the sub cam cylinder 209 and the second lens linear guide cylinder 211 without rotating.

  Further, a rotational force acts on the third lens rectilinear guide cylinder 214 that is bayonet-coupled to the sub cam cylinder 209 due to friction of the bayonet-coupled portion. Further, while the sub cam cylinder 209 rotates straight with respect to the main cam cylinder 208, a rotational force acts on the third lens rectilinear guide cylinder 214 from the sub cam cylinder 209 due to friction at the fitting portion with the main cam cylinder 208. To do. However, the rectilinear guide key groove 216 of the third lens rectilinear guide tube 214 is engaged with the rectilinear guide key 216 fixed to the guide tube 205. For this reason, the third lens rectilinear guide cylinder 214 moves straight along with the sub cam cylinder 209 in a state where rotation is blocked.

  As described above, the third lens holding cylinder 215 has the cam follower E engaged with the zoom cam groove 209D of the sub cam cylinder 209 and the rectilinear groove 214B of the third lens rectilinear guide cylinder 214. Therefore, when the sub cam cylinder 209 rotates while going straight, the third lens holding cylinder 215 goes straight with respect to the sub cam cylinder 209 and the third lens rectilinear guide cylinder 214 without rotating. For this reason, the movement amount of the third lens holding cylinder 215 in the optical axis direction is larger than the movement amount of the sub cam cylinder 209 in the optical axis direction.

  On the other hand, when the main cam cylinder 208 rotates, the fourth lens holding cylinder 217 having the cam follower 218 engaged with the fourth cam groove 208B of the main cam cylinder 208 and the rectilinear groove (not shown) on the inner periphery of the guide cylinder 205 rotates. Without going straight, it goes straight to the main cam cylinder 208.

  As described above, when the zoom operation ring 219 is rotated, the second, third, and fourth lens holding cylinders 212, 215, and 217 move straight, and the magnification (focal length) of the interchangeable lens 200 (zoom optical system 2) is increased. Change).

  Next, an operation when the focus operation ring 224 is operated during focus adjustment will be described.

  When the focus operation ring 224 is rotated, the rotational force rotates the second lens rectilinear guide tube 211 via the differential operation mechanism of the focus drive unit 2A and the focus key 2A2. At this time, the main cam cylinder 208 and the sub cam cylinder 209 do not rotate.

  When the second lens rectilinear guide tube 211 rotates, the second lens holding tube 212 having the cam follower 213 engaged with the focus cam groove portion 209B of the sub cam tube 209 and the rectilinear groove portion 211B of the second lens rectilinear guide tube 211 moves straight while rotating. To do.

  As described above, when the focus operation ring 224 is rotated, the second lens holding cylinder 212 moves straight, and the focus adjustment of the interchangeable lens 200 (zoom optical system 2) becomes possible.

  Next, an autofocus operation when the focus drive unit 2A operates according to an autofocus signal from the camera 1 will be described.

  The focus drive unit 2A includes a vibration type motor including a vibrating body whose vibration is excited by a piezoelectric element, and a rotating body that is in pressure contact with the vibrating body. When receiving an autofocus signal from the camera 1, the control board 230 drives the vibration type motor.

  The rotational force of the vibration type motor rotates the focus key 2A2 via the differential operation mechanism, and rotates the second lens linear guide tube 211 via the focus key 2A2. At this time, the main cam cylinder 208 and the sub cam cylinder 209 do not rotate.

  When the second lens rectilinear guide tube 211 rotates, the second lens holding tube 212 having the cam follower 213 engaged with the focus cam groove portion 209B of the sub cam tube 209 and the rectilinear groove portion 211B of the second lens rectilinear guide tube 211 moves straight while rotating. To do.

  Thus, by operating the focus drive unit 2A, the second lens holding tube 212 moves straight, and the interchangeable lens 200 (zoom optical system 2) can be autofocused.

  Next, a method for fixing the first lens holding cylinder 207 to the guide cylinder 205 will be described with reference to FIGS. 5, 6, and 7. FIG. 5 is an enlarged view of a part on the object side (first lens holding cylinder 207 and guide cylinder 205) in the exploded view shown in FIG. 6 shows an enlarged part of the object side in the cross-sectional structure shown in FIG. Further, FIG. 7 shows a state in which the fixing groove formed on the peripheral wall of the guide tube 205 is viewed from the outer periphery side of the guide tube 205.

  For fixing the first lens holding cylinder 207 to the guide cylinder 205, three fixing screws 229 and three screw base members 228 are used.

  The screw base member 228 has a shaft portion 228A and a base portion 228C having a larger outer diameter than the shaft portion 228A. The surface of the base portion 228C (the upper surface in FIG. 6) is formed in a spherical shape.

  At the center of the base portion 228C, a screw hole 228B is formed that opens at the surface of the base portion 228C and extends into the shaft portion 228A. The shaft portion 228A is inserted into a groove (concave portion) 207A formed on the outer peripheral surface of the first lens holding cylinder 207. As a result, the screw base member 228 is attached to the first lens holding cylinder 207 so as to be rotatable about the axis of the shaft portion 228A and the screw hole 228B. As shown in FIGS. 5 and 7, two protrusions 228D are formed on both sides of the screw hole 228B in the base portion 228C.

  Fixing grooves 205F are formed at three locations in the circumferential direction of the peripheral wall of the guide tube 205. Similarly, the three fixing groove portions 205F are formed in a phase region between the position adjusting cam groove portions 205B formed at three locations in the circumferential direction on the peripheral wall of the guide tube 205. That is, on the peripheral wall of the guide tube 205, three position adjusting cam grooves 205B and three fixing grooves 205F are alternately formed in the circumferential direction.

  In the first lens holding cylinder 207, as shown in FIG. 7, the screw hole 228B of the screw base member 228 opens inside the fixing groove 205F of the guide cylinder 205, and the protrusion 228D is inside the fixing groove 205F. It arrange | positions with respect to the guide cylinder 205 so that it may protrude.

  Here, the width of each protrusion 228C is smaller than the width of the fixing groove 205F. For this reason, the screw base member 228 can rotate with respect to the first lens holding cylinder 207 until each protrusion 228C comes into contact with the inner surface in the width direction of the fixing groove 205F of the guide cylinder 205. In other words, the screw base member 228 is prevented from further rotation by the protrusions 228C coming into contact with the inner surface in the width direction of the fixing groove 205F.

  When assembling the lens barrel, first, the screw shaft portion 229A of the fixing screw 229 is inserted into the screw hole 228B of the screw base member 228, and the fixing screw 229 is rotated in the tightening direction by a predetermined amount. In this state, the first lens holding cylinder 207 can rotate around the optical axis with respect to the guide cylinder 205, and as described above, the position of the first lens holding cylinder 207 relative to the guide cylinder 205 and the tilt angle thereof. (Hereinafter, these are collectively referred to as optical adjustment).

  The fixing groove 205F is formed to have the same lead amount (lead angle) as the position adjusting cam groove 205B. For this reason, when the first lens holding cylinder 207 is rotated around the optical axis with respect to the guide cylinder 205 for optical adjustment, the fixing screw 229 also moves in the fixing groove 205F.

  After the optical adjustment is completed, the fixing screw 229 is further rotated in the tightening direction and tightened with respect to the screw base member 228.

  When the predetermined amount of tightening and the tightening after optical adjustment are performed, the screw base member 228 is also fixed until the protrusion 228D provided on the screw base member 228 contacts the inner surface of the fixing groove 205F as described above. It can be rotated by the rotational force received from the screw 229. However, since the protrusion 228D contacts the inner surface of the fixing groove 205F, further rotation of the screw base member 228 is prevented, so that the fixing screw 229 can be fastened to the screw base member 228.

  When tightening of the fixing screw 229 after optical adjustment proceeds in this way, the peripheral wall of the guide cylinder 205 is sandwiched between the head portion 229B of the fixing screw 229 and the base portion 228C of the screw base member 228. The first lens holding cylinder 207 is fixed to the guide cylinder 205 by sandwiching three portions of the peripheral wall of the guide cylinder 205 between the three fixing screws 229 and the three screw base members 228.

  As described above, the screw base member 228 is attached to the first lens holding cylinder 207 so as to be rotatable about the shafts 228A and the screw holes 228B. For this reason, even if a rotational force acts on the screw base member 228 by tightening the fixing screw 229, the rotational force is not transmitted to the first lens holding cylinder 207. Therefore, when the fixing screw 229 is tightened, the first lens holding cylinder 207 and the guide cylinder 205 are deformed, and the optical axis position and the tilt angle of the first lens holding cylinder 207 with respect to the guide cylinder 205 are changed. Can be avoided.

  A seating surface 205FA having an outer diameter smaller than that of other portions of the outer peripheral surface is formed around the fixing groove 205F on the outer peripheral surface of the peripheral wall of the guide tube 205. The bottom surface of the head portion 229B of the fixing screw 229 that sandwiches the peripheral wall of the guide cylinder 205 between the screw base member 228 and the seat surface 205FA makes the head portion 229B of the fixing screw 229 the outer periphery of the peripheral wall of the guide cylinder 205. Large protrusion from the surface is avoided.

  In a state where the peripheral wall of the guide tube 205 is sandwiched between the head 229B of the fixing screw 229 and the base portion 228C of the screw base member 228, the spherical surface of the base portion 228C contacts the inner surface of the peripheral wall of the guide tube 205. .

  As shown in FIGS. 9 and 10, in the AA cross section along the circumferential direction of the peripheral wall of the guide tube 205, the radius of curvature of the spherical surface is larger than the radius of curvature of the inner surface of the peripheral wall of the guide tube 205. However, in the BB cross section along the direction in which the fixing groove 205F extends, the curvature radius of the spherical surface is smaller than the curvature radius of the inner surface of the peripheral wall of the guide tube 205. Thereby, the screw base member 228 can stably sandwich the peripheral wall of the guide tube 205 with the head 229B of the fixing screw 229.

  A method for setting the radius of curvature of the spherical surface of the base portion 228C will be described. The curvature radius of the spherical surface may be calculated by the following calculation formula based on the diameter of the inner surface of the peripheral wall of the guide tube 205 and the lead amount (lead angle) of the fixing groove 205F.

A radius R1 of the inner surface of the peripheral wall of the guide tube 205 is set, and a lead angle of the fixing groove 205F is set to θ1. At this time, the radius of curvature of the spherical surface SR1 is
SR1 = R1 × (1 / cos θ1)
(However, θ1 is smaller than 90 °)
It can be calculated by the following formula.

  7 shows a case where the screw base member 228 is provided with two protrusions 228D on both sides of the screw hole 228B. As shown in FIG. 8, the screw base 228 has a screw hole 228B at the center. Two protrusions 228D ′ may be provided. In this case, the rotation of the screw base member 228 is prevented by the two portions of the one protrusion 228D ′ coming into contact with the inner surface of the fixing groove 205F.

  The embodiments described above are merely representative examples, and various modifications and changes can be made to the above-described embodiments when implementing the present invention.

  For example, although the interchangeable lens has been described in the above embodiment, the present invention can also be applied to an optical apparatus such as a digital still camera or a video camera that has a zoom optical system integrally.

1 is a diagram showing a schematic configuration of an interchangeable lens that is an embodiment of the present invention and a camera equipped with the same. FIG. 2 is a block diagram showing an electrical configuration of the interchangeable lens and camera shown in FIG. 1. Sectional drawing of the interchangeable lens of an Example. FIG. 3 is an exploded perspective view of a part of the interchangeable lens of the example. The disassembled perspective view which expanded a part of disassembled perspective view shown in FIG. Sectional drawing which expanded a part of sectional drawing shown in FIG. The top view which shows the groove part for fixation and the screw base member in the interchangeable lens of an Example. The top view which shows the modification of the said screw base member. The figure which shows the cutting line of the guide cylinder and screw base member in the interchangeable lens of an Example. Sectional drawing which shows a guide cylinder and a screw base member when it cut | disconnects by the cutting line of FIG.

DESCRIPTION OF SYMBOLS 1 Camera 2 Zoom optical system 5 Lens barrel 6 Image pick-up element 8 Shake sensor 12 Correction lens unit L1-L7 1st-7th lens unit 2A Focus drive unit 2B Anti-vibration unit 2C Electric aperture unit 203 Base cylinder 204 Intermediate cylinder 205 Guide Tube 205B Cam groove portion 205D, 209B, 209D Cam groove portion 205F Fixing groove portion 207 First lens holding tube 208 Main cam tube 208A, 214B Rectilinear guide groove portion 209 Sub cam tube 211 Second lens rectilinear guide tube 212 Second lens holding tube 213 , C, E Cam follower 214 Third lens linear guide cylinder 215 Third lens holding cylinder 216 Linear guide key 217 Fourth lens holding cylinder 219 Zoom operation ring 220, 221 Gear ring 222 Gear unit 223 Zoom lever 224 Four Scan operation ring 225 fifth lens holding barrel 226 sixth lens holding cylinder 227 seventh lens holding cylinder 228 threaded base member 228B threaded hole 228D protrusion 229 fixing screw

Claims (3)

A lens holding member for holding the lens;
A support cylinder having a peripheral wall that supports the lens holding member and has a fixing groove and an adjustment groove engaged with a follower provided in the lens holding member ;
A threaded hole, and a screw base member which is attach to the lens holding member,
A screw that is tightened into the screw hole through the fixing groove, and the head is fixed to the support cylinder by sandwiching the peripheral wall of the support cylinder with the screw base member. A screw and
It is possible to adjust the position of the lens holding member relative to the support tube by moving the follower along the adjustment groove, and to adjust the tilt angle of the lens holding member relative to the support tube by eccentric rotation of the follower. And
The screw base member is
The protrusion has a width smaller than the width of the fixing groove and protrudes into the fixing groove, and has a protrusion that prevents rotation of the screw base member by contacting the inner surface of the fixing groove .
It is attached to the lens holding member so as to be rotatable around the axis of the screw hole as the fixing screw is tightened until the protrusion comes into contact with the inner surface of the fixing groove. Optical equipment. The surface that sandwiches the peripheral wall of the support cylinder between the head of the fixing screw in the screw base member is a spherical surface,
Wherein in a cross section along a direction fixing groove extends, optical apparatus of claim 1, the radius of curvature of the spherical surface, and wherein the smaller than the radius of curvature of the peripheral wall.   3. The optical apparatus according to claim 2, wherein a radius of curvature of the spherical surface is larger than a radius of curvature of the circumferential wall in a cross section along the circumferential direction of the circumferential wall.