JP4348143B2 - Lens adjustment device - Google Patents

Description

  The present invention relates to a lens position adjustment device, and more particularly to a tilt device that adjusts the tilt of a lens optical axis.

In a lens barrel, even if individual parts are manufactured within tolerances, errors in the respective parts may accumulate in the assembled state, resulting in a non-negligible effect on optical performance. In particular, in recent years, optical systems have been miniaturized, and there is a tendency to require stricter accuracy than before. For this reason, various lens adjustment devices have been proposed in order to ensure optical performance in the assembled state. For example, Japanese Patent No. 2794424 proposes a tilt device that uses an eccentric cam pin to adjust the tilt of the optical axis of the lens. In this tilt device, three eccentric cam pins that can rotate on an axis orthogonal to the optical axis are provided at predetermined intervals in the circumferential direction of the lens barrel, and the lens frame is supported at three points by the three eccentric cam pins. . When the three eccentric cam pins are rotated appropriately, the position in the optical axis direction changes, and the optical axis angle of the lens changes.
Japanese Patent No. 2794424

In the conventional adjustment method described above, the three eccentric cam pins must be individually operated, and it is difficult to intuitively understand how much of the eccentric cam pin should be operated with respect to the actual tilting of the optical axis. It took time to make adjustments. The present invention provides a lens adjustment device that eliminates such complexity and can easily adjust the tilt of the optical axis.

The lens adjusting device of the present invention forms a sliding contact outer spherical surface that forms at least a part of the outer surface of a sphere centered on a point on the optical axis on the outer periphery of the lens frame to which the lens is fixed, and holds the lens frame A sliding contact inner spherical surface that is in contact with the sliding contact outer spherical surface at the same center as the sliding contact outer spherical surface is formed on the inner peripheral portion of the holding frame, and is screwed into a screw hole formed in the outer peripheral portion of the lens frame. A tilt adjustment screw protruding in the outer diameter direction from the lens frame, and a screw guide parallel to the central axis of the holding frame formed on the holding frame so that the tilt adjustment screw is movably fitted while restricting relative rotation. A groove and a circumferential position adjusting means for changing a circumferential position of the screw guide groove and a tilt adjusting screw about the central axis of the holding frame are provided. When the tilt adjustment screw is moved back and forth along the screw guide groove in the unlocked state, the lens frame and the holding frame are fixed or released from each other according to the radial advance / retreat position of the tilt adjustment screw with respect to the screw hole. The lens frame tilts as the sliding outer spherical surface slides relative to the inner spherical surface.

  It is preferable that a pair of tilt adjustment screws and screw guide grooves are provided at different positions at equal intervals in the circumferential direction of the lens frame and the holding frame.

  The present invention can be applied as a support structure of a movable lens group that can move in the optical axis direction according to the rotation of the cam ring. In this case, the holding frame is composed of a first frame and a second frame, and the first frame has a follower that engages with the cam groove of the cam ring and a sliding outer spherical surface of the lens frame. A first sliding inner spherical surface that is in contact with the second frame, and a sandwiched ring that is located radially outside the first frame and sandwiches the first frame with the lens frame And a second sliding contact inner spherical surface that contacts the sliding outer spherical surface of the lens frame in addition to the first sliding contact inner spherical surface, and the screw guide groove is formed in the second frame body to tilt. The first frame, the second frame, and the lens frame may be fastened together with the adjustment screw.

When the holding frame is composed of the first and second frame bodies, a circumferential groove formed in the outer peripheral portion of the first frame body, and a sandwiched ring of the second frame body positioned outside the circumferential groove. A circumferential position having a through-screw hole in the radial direction formed in the portion and a guide projection that engages with the circumferential groove at the tip, and a threaded portion that is screwed into the through-screw hole at the base of the guide projection A circumferential position adjusting means can be constituted by the adjusting screw. That is, the first frame body and the second frame body are fixed or released from each other in accordance with the radial advancement / retraction position of the circumferential position adjustment screw with respect to the through screw hole, and the guide projections in the circumferential groove in the fixed release state. Can move along.

When the present invention is applied to a lens barrel having a cylindrical body covering the outside of the lens frame and the holding frame, the tilt adjustment screw is operated from the outside of the cylindrical body through the cylindrical body in the radial direction. Workability is good when a penetrating operation hole is provided. Similarly, the circumferential position adjusting screw may be provided with a through operation hole that can be operated from the outside of the cylindrical body.

According to the present invention described above, it is possible to obtain a lens adjustment device that can easily adjust the tilt of the optical axis.

  1 and 2 are schematic cross-sectional views of a zoom lens barrel 10 having a lens adjusting device to which the present invention is applied. FIG. 1 shows a state before adjusting the tilt of the optical axis, and FIG. 2 shows a state after adjustment. ing. The photographing optical system in the zoom lens barrel 10 includes a first lens unit L1, a second lens unit L2, a diaphragm A, and a third lens unit L3 in order from the front in the optical axis direction. Zooming is performed by moving them relative to each other. The zoom lens barrel 10 can be attached to and detached from a camera body (not shown) via a mount ring 11, and the camera body has a built-in shutter.

  A fixed ring (cylindrical body) 12 is fixed to the front portion of the mount ring 11. The fixed ring 12 has a concentric outer cylinder part 13 and an inner cylinder part 14 centered on the optical axis O, and the rear end part of the outer cylinder part 13 and the inner cylinder part 14 is coupled to the mount ring 11. It has a letter-shaped cross-sectional shape. In a state where the mount ring 11 is attached to the camera body, the fixed ring 12 is fixed to the camera body and neither rotates nor moves in the optical axis direction.

  A zoom ring (tubular body) 15 is supported on the outer peripheral surface of the outer cylindrical portion 13 so as to be rotatable about the optical axis O. The zoom ring 15 extends a zoom lever 16 in the inner diameter direction. The zoom lever 16 is fixed to the cam ring (tubular body) 20 through a radial through hole 13 a formed in the outer cylindrical portion 13. The cam ring 20 is supported on the outer peripheral surface of the inner cylindrical portion 14 and is rotatable about the optical axis O. Therefore, the zoom ring 15 and the cam ring 20 rotate together via the zoom lever 16. The through hole 13a is formed long in the circumferential direction so as not to interfere with the zoom lever 16 when the zoom ring 15 and the cam ring 20 rotate.

  Three types of cam grooves C1, C2, and C3 are formed in the cam ring 20 from the front in the optical axis direction. A cam follower 21a provided in a first group moving frame 21 that supports the first lens group L1 is engaged with the cam groove C1, and a second group movement that supports the second lens group L2 is engaged with the cam groove C2. The cam follower 22a provided in the frame (holding frame, first frame) 22 is engaged, and the cam follower 23a provided in the third group moving frame 23 supporting the third lens group L3 is engaged with the cam groove C3. Match. The second group moving frame 22 and the third group moving frame 23 are located inside the inner cylinder part 14, whereas the first group moving frame 21 is located between the cam ring 20 and the outer cylinder part 13 (the outer periphery of the inner cylinder part 14). Supported on the surface side). Accordingly, the cam follower 21a protrudes from the first group moving frame 21 toward the inner diameter direction, and the cam follower 22a and the cam follower 23a protrude from the second group moving frame 22 and the third group moving frame 23 toward the outer shape, respectively. . Each of the cam followers 21a, 22a, and 23a is further engaged with a rectilinear guide groove 24 parallel to the optical axis O formed in the inner cylindrical portion 14, and is linearly guided in the optical axis direction. That is, the first group moving frame 21, the second group moving frame 22, and the third group moving frame 23 are movable in the direction along the optical axis O and do not rotate around the optical axis O, so that the linear guide groove 24 is moved. Be guided by.

  From the above configuration, when the zoom ring 15 is rotated, the cam ring 20 rotates, and when the cam ring 20 rotates, the first group moving frame 21, the second group moving frame 22, and the third group moving frame 23 correspond to the corresponding cam groove C1. It moves forward and backward along a predetermined locus in the optical axis direction according to the shape of C3. Zooming is performed by relative movement of the three lens groups L1 to L3 in the optical axis direction. The stop A is supported by the third group moving frame 23 and moves together with the third lens group L3.

  In the zoom lens barrel 10, the support mechanism of the second lens unit L2 is provided with tilt adjustment means for tilting the optical axis. The member that directly holds the second lens group L2 is a second group lens frame (lens frame) 30, and the second group lens frame 30 uses the second group holding frame (holding frame, second frame) 31 to The second group moving frame 22 is fixed.

  As shown in FIG. 3, the outer peripheral portion of the second group lens frame 30 is formed as a sliding contact outer spherical surface P1, which is a part of the outer surface of a sphere having a radius r centered on an arbitrary center point K on the optical axis O. ing. The second group holding frame 31 has a radial flange 32 that does not overlap with the second group moving frame 22 in a partial region in the front of the optical axis direction, and is radially outside the second group moving frame 22 behind the radial flange 32. The slidable inner spherical surface (second slidable inner spherical surface) P <b> 2 is formed on the inner circumferential portion of the radial flange 32. The sliding contact inner spherical surface P2 is a part of the inner surface of the same sphere (center point K, radius r) as the sliding contact outer spherical surface P1, and slidably contacts the sliding contact outer spherical surface P1 of the second group lens frame 30. .

  As shown in FIG. 3, the distal end portion of the second group moving frame 22 is surrounded by the radial flange 32 and the clamping ring portion 33 of the second group holding frame 31 and the sliding contact outer spherical surface P <b> 1 of the second group lens frame 30. The space S is inserted from the rear in the optical axis direction. Similar to the sliding contact inner spherical surface P2, the inner peripheral surface near the tip of the second group moving frame 22 has a sliding inner spherical surface (first surface) that is the inner surface of a sphere having a radius r centered on the center point K on the optical axis. 1 slidable contact inner spherical surface) P3 is formed. When the distal end portion of the second group moving frame 22 is inserted into the space S, the sliding inner spherical surface P3 comes into slidable contact with the outer sliding spherical surface P1 of the second group lens frame 30. Further, the outer peripheral surface 22b of the second group moving frame 22 and the inner peripheral surface 33a of the sandwiching ring portion 33 are cylindrical surfaces centered on the optical axis O, and both peripheral surfaces are in contact with each other so as to be relatively rotatable in the circumferential direction.

  The second group holding frame 31 is formed with a first screw screw hole (through screw hole) 34 and a screw guide groove 35 that pass through the pinched ring portion 33 in the radial direction with different front and rear positions in the optical axis direction. ing. Among these, a screwing portion 40 a provided on the base side of the first screw (circumferential position adjusting screw) 40 can be screwed into the first screw screwing hole 34 positioned rearward in the optical axis direction. The first screw 40 has a small-diameter guide pin (guide protrusion) 40b on the distal end side of the threaded portion 40a. The guide pin 40b is a circumferential groove 36 formed on the outer peripheral surface 22b of the second group moving frame 22. (See FIGS. 6 to 9). When the screwing portion 40a of the first screw 40 is tightened into the first screw screwing hole 34, the tip end portion of the guide pin 40b is pressed against the bottom surface of the circumferential groove 36, and the second group moving frame 22 and the second group holding member are pressed. The frames 31 are fixed to each other. That is, the movement of the guide pin 40b in the circumferential groove 36 is restricted. On the other hand, when the screwing of the first screw screwing hole 34 and the screwing part 40a is loosened, the second group moving frame 22 and the second group pressing frame 31 are guided by the circumferential groove 36 and the guide pin 40b so as to be relatively rotatable. Become.

  The screw guide groove 35 is formed as a long groove in a direction along the optical axis O (a direction parallel to the central axis of the second group holding frame 31), and is movable in the longitudinal direction with respect to the screw guide groove 35. The second screw (tilt adjustment screw) 41 is inserted in a state where movement is restricted in the circumferential direction. The axis of the second screw 41 is oriented in the radial direction with the center point K as the center. The screw guide groove 35 opens to the outer peripheral surface side of the second group pressing frame 31 through the opening recess 37. As can be seen from FIG. 5, the opening recess 37 is wider than the screw guide groove 35, and a curved bottom surface 38 is formed at the bottom of the opening recess 37. The curved bottom surface 38 is formed as an arcuate surface concentric with the spherical surfaces P1, P2 and P3, and a screw head 41s of the second screw 41 is in contact with the curved bottom surface 38. A second screw screw hole (screw hole) 39 is formed on the sliding outer spherical surface P1 of the second group lens frame 30. The second screw screw hole 39 is located inside the screw guide groove 35. On the other hand, the tip of the second screw 41 inserted into the screw guide groove 35 can be screwed.

  The second group moving frame 22, the second group lens frame 30, and the second group pressing frame 31 are fastened together by fastening the second screw 41. That is, when the second screw 41 is tightened so that the second group moving frame 22 is inserted into the space S between the second group lens frame 30 and the second group holding frame 31 so as to proceed in the inner diameter direction of the barrel, The inner peripheral surface 33a of the clamping ring portion 33 of the frame 31 presses the outer peripheral surface 22b of the second group moving frame 22 against the second group lens frame 30 side, and the sliding contact outer spherical surface P1 and the sliding contact inner spherical surface P3 are brought into close contact by this pressing force. Is done. At the same time, the second group holding frame 31 closely contacts the sliding contact inner spherical surface P2 formed on the radial flange 32 with the sliding contact outer spherical surface P1. As a result, the second group moving frame 22 is sandwiched between the second group lens frame 30 and the second group holding frame 31, and the second group moving frame 22, the second group lens frame 30, and the second group holding frame 31 are integrated. The Conversely, when the second screw 41 is loosened so as to proceed in the outer diameter direction of the lens barrel, the sliding outer spherical surface P1 of the second group lens frame 30 is slid with respect to the sliding inner spherical surface P2 and the sliding inner spherical surface P3. Is possible. In addition, the outer peripheral surface 22b and the inner peripheral surface 33a can be slidably contacted with the second group moving frame 22, and the second group pressing frame 31 can be rotated about the optical axis. It is also possible to rotate the second lens group frame 30 by sliding the inner spherical surface P3. However, since the second screw 41 is restricted from moving in the circumferential direction with respect to the screw guide groove 35, the second group lens frame 30 and the second group holding frame are both in the tightened state and the loosened state. 31 is relatively unrotatable.

  As shown in FIG. 6, a pair of second screws 41 and screw guide grooves 35 are provided at intervals of 180 degrees in the circumferential direction so as to be arranged symmetrically with respect to the center point K of the spherical surfaces P1 to P3. . In FIG. 6, the first screw 40 and the first screw screw hole 34 are also provided with a pair at intervals of 180 degrees in the circumferential direction, although they are not visible because they are located behind the second screw 41. As shown in FIG. 1, the zoom lens barrel 10 has a pair of driver insertion holes (penetrating holes) in order to allow each pair of first and second screws 40 and 41 to be rotated from the outside in a completed state. An operation hole) 42 and a pair of driver insertion holes (penetration operation holes) 43 located behind the operation hole 42 are formed. The driver insertion holes 42 and 43 pass through the inner cylinder portion 14, the cam ring 20, the outer cylinder portion 13, and the zoom ring 15 in order from the inner diameter side of the lens barrel, and cover rings attached to the outer peripheral surface of the zoom ring 15 17 covers the opening. The cover ring 17 is made of an elastic material such as rubber, and normally covers all the driver insertion holes 42 and 43 so as to block harmful light from entering the lens barrel. 42 and 43 can be exposed. The cover ring 17 also functions as a finger hook when the zoom ring 15 is rotated.

  When the pair of second screws 41 are moved back and forth in the optical axis direction along the screw guide groove 35, the sliding contact outer spherical surface P1 is slid with respect to the sliding contact inner spherical surface P2 and the sliding contact inner spherical surface P3, and the second group The lens frame 30 tilts in the front-rear direction about the center point K on the optical axis. At this time, the screw head 41s moves along the curved bottom surface 38 concentric with the spherical surfaces P1 to P3, so that the tilting of the second group lens frame 30 is not hindered. When the second group lens frame 30 is tilted, as shown in FIG. 4, the optical axis of the second lens group L2 (center axis of the second group lens frame 30) is the optical axis of the other lens groups L1 and L3 (two group moving frame). 22 and the center axis of the second group holding frame 31). The tilt angle of the second lens unit L2 at this time corresponds to the amount of movement of the second screw 41 in the front-rear direction (the tilt angle of the axis of the second screw 41). For example, as shown in FIG. When the second screw 41 is tilted forward by the angle α, the optical axis of the second lens unit L2 is tilted downward by the angle α. A pair of second screws 41 are provided at axially symmetric positions, and the movement of each second screw 41 in the circumferential direction with respect to the screw guide groove 35 is restricted, so that the light of the second lens unit L2 The axis always tilts in a plane Q (FIG. 6) including the axis of the pair of second screws 41 and the center point K.

  The procedure for adjusting the tilt of the optical axis with the above configuration will be described with reference mainly to FIGS. 7 to 9 show a part in which the second group moving frame 22, the second group lens frame 30 and the second group pressing frame 31 are viewed from the front, and a part in plan view of the vicinity of the upper first screw 40 and the second screw 41. In the part viewed from the front, the vertical direction in the drawing corresponds to the vertical direction of the zoom lens barrel 10, and in the part viewed from the top, the vertical direction in the drawing corresponds to the longitudinal direction of the optical axis.

  When the zoom lens barrel 10 is assembled, the second screw 41 is temporarily tightened with a strength that allows sliding of the sliding contact outer spherical surface P1 and the sliding contact inner spherical surfaces P2 and P3. The second group lens frame 30 and the second group pressing frame 31 are integrated. Then, when the zoom lens barrel 10 is assembled, the tilt of the optical axis is checked by a projection chart.

  FIG. 7 shows a state before the tilt adjustment. At this time, each of the pair of second screws 41 is located at a substantially central portion in the longitudinal direction of the inserted screw guide groove 35. That is, when the periphery of the second screw 41 is viewed in a longitudinal section, the state is as shown in FIG. As described above, the inside of the plane Q including the axis of the pair of second screws 41 (thick arrow direction in FIG. 7) is a tiltable direction. As a result of the optical performance check, the arrow T not included in the plane Q Suppose that the tilt of the optical axis in the direction becomes necessary.

  First, as shown in FIG. 8, the second group lens frame 30 and the second group pressing frame 31 are rotated so that the arrow T, which is the direction to be tilted, is included in the tiltable plane Q. This rotation operation is performed after the first screw 40 is loosened. As described above, when the first screw 40 is loosened, the second group lens frame 30 and the second group pressing frame 31 can be rotated relative to the second group moving frame 22. Since the rotation of the second group moving frame 22 is restricted by the engagement of the cam follower 22a and the rectilinear guide groove 24, when the first screw 40 is moved in the circumferential direction with the first screw 40 loosened, the guide pin 40 b is guided by the circumferential groove 36, and the combined body of the second group lens frame 30 and the second group pressing frame 31 rotates with respect to the second group moving frame 22. Since both the screw guide groove 35 and the second screw 41 are provided on the rotating second group lens frame 30 and the second group holding frame 31, the angle of the tiltable plane Q changes as shown in FIG. .

  When the state shown in FIG. 8 is reached, the pair of first screws 40 are tightened, and the second group moving frame 22 and the second group holding frame 31 are fixed. Thereby, even if the second screw 41 is loosened, the relative position between the sliding contact inner spherical surface P2 on the second group holding frame 31 side and the sliding contact inner spherical surface P3 on the second group moving frame 22 side does not shift. At this time, the pair of second screws 41 are in a temporarily tightened state that allows the sliding outer spherical surface P1 to slide with respect to the sliding inner spherical surfaces P2 and P3. Only the second group lens frame 30 is movable with respect to the group moving frame 22 and the second group holding frame 31. If the second screw 41 is tightened too much, the second group lens frame 30 is moved by loosening it.

  At this time, since the required tilt direction T coincides with the tiltable plane Q, the pair of second screws 41 are moved in the front-rear direction so that the optical axis of the second lens unit L2 is inclined in the T direction. . Specifically, as shown in FIG. 9, when the upper second screw 41 (41A) is moved in the direction of the front end of the screw guide groove 35 (strictly, tilting about the center point K. The same applies hereinafter) The sliding outer spherical surface P1 slides on the sliding inner spherical surfaces P2 and P3, the optical axis of the second lens unit L2 is inclined in the T direction, and the upper second screw 41 (41A) is moved behind the screw guide groove 35. When moved in the end direction, the optical axis of the second lens unit L2 is tilted in the T ′ direction opposite to the T direction. At this time, the lower second screw 41 (41B) moves to a position symmetrical to the upper second screw 41 (41A) with respect to the tilt center point K of the second lens unit L2. That is, when tilting in the T direction, it moves toward the rear end of the screw guide groove 35, and when tilting in the T 'direction, it moves in the direction of the front end. Since the pair of second screws 41 function in conjunction with each other, either the upper or lower second screws 41 may be operated during adjustment.

  The vertical section of the tilt mechanism corresponding to FIG. 9 is FIG. 4. As shown in FIG. 4, the tilt of the optical axis of the entire photographing optical system is corrected by tilting the second lens unit L2 by a predetermined angle (α) in the T direction. Then, the pair of second screws 41 are tightened to fix the second group lens frame 30 to the second group moving frame 22 and the second group holding frame 31 again. As a result, the second lens unit L2 is maintained at the angle after tilt adjustment as shown in FIG.

  As described above, in the tilt adjustment operation of the optical axis, the first screw 40 is rotated in the circumferential direction for aligning the tiltable plane Q and the tilt direction T with the rotation operation of the screw itself at the time of fixing and unlocking. And move. In addition, for the second screw 41, a rotation operation of the screw itself at the time of fixing and releasing the fixing, and a back-and-forth movement operation (tilting about the center point K) for adjusting the tilt angle of the second group lens frame 30 are performed. Do. When performing any of the operations, the driver insertion hole 42 or 43 is exposed by turning the cover ring 17 made of an elastic material, and if the operation target is the first screw 40, the screw insertion hole 43 may be connected to the second screw 41. For example, a driver may be inserted into the driver insertion hole 42. The driver insertion hole 42 is formed with a sufficient opening width in the front-rear direction so as not to interfere with the driver when the second screw 41 is moved in the front-rear direction. Further, although the circumferential shape of the driver insertion hole 43 is not shown in FIGS. 1 and 2, it is sufficiently long in the circumferential direction so as not to interfere with the driver when the first screw 40 is moved in the circumferential direction. Have Therefore, the work relating to the tilt adjustment of the optical axis can be performed while looking at the projection chart without disassembling the zoom lens barrel 10. In this embodiment, the cover ring 17 is an elastic member. However, the cover ring 17 may be a detachable type with respect to the zoom ring 15 and may be structured such that the cover ring 17 is removed during adjustment.

  As can be seen from the above description, according to the configuration of the present embodiment, the second group lens frame 30 is supported by the spherical surface and the tiltable plane Q coincides with the tilt direction T, and the second screw 41 is moved back and forth. The tilt of the optical axis can be adjusted simply by moving it in the direction. Of course, when the tilt direction T and the tiltable plane Q coincide from the beginning, it is only necessary to move the second screw 41 back and forth. This tilt method is easier to understand and easier to perform than the conventional tilt operation based on the correlation of the eccentric pins supported at three points, and is excellent in workability.

  In the present embodiment, the screw insertion holes 42 and 43 are provided so that the tilt adjusting screws 40 and 41 can be operated from the outside. Therefore, unlike the first lens group L1, the second lens group L2 that is not exposed to the outside. Can be adjusted without disassembling the lens barrel, and the workability is further improved.

  However, the present invention is not limited to the illustrated embodiment. For example, in the embodiment, a pair of screws 40 and 41 are provided at intervals of 180 degrees in the circumferential direction. However, the tilt adjustment of the optical axis can be performed if there is at least one screw.

  In the embodiment, the tilt adjustment of the optical axis is performed by the movable lens group (second lens group L2) that is advanced and retracted in the optical axis direction by the rotation of the cam ring 20, but the fixed lens that does not move in the optical axis direction is tilted. Adjustments may be made. For example, if the second group moving frame 22 in the embodiment is a fixing member to the fixed ring 12, the second lens group L2 becomes a fixed lens group.

Needless to say, the application target of the present invention is not limited to the three-group zoom type optical system as in the illustrated embodiment.

It is a longitudinal cross-sectional view of a zoom lens barrel having a lens adjustment device to which the present invention is applied. FIG. 3 is a longitudinal sectional view of the zoom lens barrel of FIG. 1 with a second lens group tilted. FIG. 3 is an enlarged longitudinal sectional view of the vicinity of a support mechanism for a second lens group in the zoom lens barrel of FIG. 1. FIG. 3 is an enlarged longitudinal sectional view of the vicinity of a support mechanism of a second lens group in the tilt state of FIG. 2. FIG. 4 is a plan view of a second group pressing frame as viewed from the direction of arrow V in FIG. 3. It is the figure which looked at the 2nd group lens frame, the 2nd group press frame, and the 2nd group moving frame from the front. It is a figure which shows the state before adjustment in an example of the tilt adjustment operation | work of an optical axis. It is a figure which shows the state in the middle of the adjustment operation | work. It is a figure showing the state where the adjustment work was completed.

Explanation of symbols

C1 C2 C3 Cam groove K Center of sliding inner spherical surface and sliding outer spherical surface L1 First lens group L2 Second lens group L3 Third lens group P1 Sliding outer spherical surface P2 Sliding inner spherical surface (second sliding inner spherical surface )
P3 Sliding contact inner spherical surface (first sliding contact inner spherical surface)
Q Tiltable plane 10 Zoom lens barrel 12 Fixed ring (cylindrical body)
13 Outer cylinder part 14 Inner cylinder part 15 Zoom ring (cylindrical body)
17 Cover ring 20 Cam ring (tubular body)
21 First group moving frame 22 Second group moving frame (holding frame, first frame)
23 3rd group moving frame 21a 22a 23a Cam follower 24 Straight guide groove 30 2nd group lens frame (lens frame)
31 2 group holding frame (holding frame, second frame)
32 radial flange 33 clamping ring 34 first screw screw hole (through screw hole)
35 Screw guide groove 36 Circumferential groove 37 Opening recess 38 Curved bottom surface 39 Second screw screw hole (screw hole)
40 First screw (Circumferential position adjustment screw)
40a Threaded portion 40b Guide pin (guide protrusion)
41 (41A 41B) Second screw (tilt adjustment screw)
41s screw head 42 43 driver insertion hole (penetration operation hole)

Claims (6)

A sliding outer spherical surface formed on the outer peripheral portion of the lens frame to which the lens is fixed and forming at least a part of the outer surface of a sphere centered on a point on the optical axis;
It formed in the inner peripheral portion of the holding frame for holding the lens frame, sliding the ball surface which is in contact with the sliding Seggai spherical above sliding Seggai spherical and the same center;
A tilt adjusting screw that is screwed into a screw hole formed on the outer periphery of the lens frame and protrudes from the lens frame in the outer diameter direction;
A screw guide groove formed in the holding frame in parallel with the central axis thereof, the relative rotation about the central axis being restricted, and the tilt adjusting screw being movably fitted; and
A circumferential position adjusting means for changing a circumferential position of the tilt adjusting screw and the screw guide groove around the central axis of the holding frame;
Have
The lens frame and the holding frame are fixed or released from each other according to the radial advancement / retraction position of the tilt adjustment screw with respect to the screw hole, and the tilt adjustment screw is moved back and forth along the screw guide groove in the unlocked state. The lens adjusting device according to claim 1, wherein when the lens is moved, the sliding contact outer spherical surface slides with respect to the sliding contact inner spherical surface, and the lens frame tilts with respect to a central axis of the holding frame. In the lens adjustment apparatus of claim 1, it has a cylindrical body covering the outside of the lens frame and the holding frame, outside of the cylindrical body the tilting adjustment screw through the tubular body in the radial direction Lens adjustment device having a through operation hole that enables operation from the outside. In the lens adjustment apparatus of claim 1 or 2, wherein the tilt adjusting screw and the screw guide grooves, respectively, lens adjustment is provided a pair at different positions at equal intervals in the circumferential direction of the lens frame and the holding frame apparatus. In the lens adjustment apparatus according to any one of claims 1 to 3, the lens is a movable lens group movable in the optical axis direction in accordance with rotation of the cam ring, the holding frame,
Radial and the first frame; and follower that engages the cam groove of the cam ring, the first frame member having a first sliding the spherical surface contact with the sliding contact outer spherical surface of the lens frame a clamping ring portion sandwiching the first frame between the lens frame located outside, the second in contact with the sliding contact outer spherical separately from the lens frame and the first sliding the spherical A second frame having a sliding contact inner spherical surface;
With
The bis guide groove is formed in the second frame, a lens adjusting apparatus of the first frame member by said tilt adjustment screw, the second frame and the lens frame are fastened together. 5. The lens adjusting device according to claim 4, wherein the circumferential position adjusting means is
A circumferential groove formed in the outer periphery of the first frame;
Yes to and tip the guide projection that engages in the circumferential groove; in the clamping ring portion of the second frame, through screw holes in the radial direction which is formed by the position on the outside of the circumferential groove And a circumferential position adjustment screw having a screwing portion screwed into the through screw hole at the base portion of the guide projection;
Have
Depending on the forward and backward position in the radial direction of the circumferential position adjusting screw relative to the through screw hole, the first frame and the second frame is fixed or unlocking each other, the guide protrusion in the unlocking state Is a lens adjustment device that can move along the circumferential groove. In the lens adjustment apparatus according to claim 5, has a cylindrical body covering the outside of the lens frame and the holding frame, the circumferential position adjusting screw to the cylindrical body through the tubular body in the radial direction Lens adjustment device having a through operation hole that enables operation from the outside of the lens.

Images