JP2006259595A - Zoom lens barrel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a zoom lens barrel capable of preventing the degradation of product performance and reducing manufacturing cost. <P>SOLUTION: The zoom lens barrel has: a zoom ring 15 which is operated at the time of a zooming operation; a plurality of transfer groups 7, 19 which are transferred in the optical axis direction in accordance with rotation of the zoom ring 15; a plurality of control rings 9, 17, 21, 23 which control an amount of transfer of the plurality of transfer groups 7, 19; at least one first interlocking member 27 for interlocking at least one control ring 17 among the plurality of control rings with the zoom ring 15; and at least one second interlocking member 33 for interlocking the plurality of control rings 17, 23. In the zoom lens barrel, positions of the first interlocking member 27 and the second interlocking member 33 are adjustable in the circumferential direction with an optical axis as center. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a zoom lens barrel.

Conventionally, a zoom lens barrel that moves a plurality of lens groups to a predetermined position by rotating the zoom ring during zooming transmits the rotation of the zoom ring to the cam ring by a first interlocking key fixed to the zoom ring, The second interlocking key fixed to the cam ring is transmitted to the rotating ring. A cam groove or rectilinear groove is formed in the cam ring and the rotary ring, and the cam groove or rectilinear groove and a cam groove or rectilinear groove formed in a plurality of sliding rings to which the lens group is fixed are interposed via a cam follower pin. Are connected. During zooming, the rotation of the zoom ring is converted into a straight movement of the sliding ring via the cam ring and the rotating ring, and each lens group fixed to the plurality of sliding rings is moved to a predetermined position. (For example, see Patent Document 1).
JP 2004-191558 A

  However, in the conventional zoom lens barrel, the key grooves that engage with the first and second interlocking keys and the screw holes that fix the first and second interlocking keys cannot be adjusted in the rotational direction. As a result, the assembly position of the cam ring, rotating ring, and slide ring due to manufacturing errors of the cam parts that make up the zoom lens barrel deviates from the initial position (design position), and the lens position during zooming deviates from the design position. Therefore, there is a problem that the imaging performance deteriorates. Further, there is a problem that a member having a large error is discarded, leading to an increase in manufacturing cost.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a zoom lens barrel capable of preventing a reduction in product performance and reducing a manufacturing cost.

  In order to achieve the above object, the present invention controls a zoom ring operated during zooming operation, a plurality of movement groups that move in the optical axis direction as the zoom ring rotates, and a movement amount of the plurality of movement groups. A plurality of control rings, at least one first interlocking member that interlocks at least one control ring and the zoom ring, and at least one second interlocking the plurality of control rings. There is provided a zoom lens barrel characterized in that it has an interlocking member, and the first interlocking member and the second interlocking member can be adjusted in the circumferential direction around the optical axis.

  In the zoom lens barrel according to the present invention, it is preferable that the first interlocking member and the second interlocking member are elongated holes in which a fixing screw hole is long in a circumferential direction centering on the optical axis.

  ADVANTAGE OF THE INVENTION According to this invention, the zoom lens barrel which can prevent the fall of product performance and can reduce manufacturing cost can be provided.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 to 3.

  FIG. 1 is a half cross-sectional view of a zoom lens barrel according to an embodiment of the present invention. FIG. 2 is a development view of the zoom lens barrel according to the embodiment of the present invention. FIG. 3 is a diagram for explaining a method of adjusting the zoom lens barrel according to the embodiment of the present invention.

  1 and 2, each zoom lens barrel member is disposed with a fixed cylinder 5 fixed to a lens mount 1 with screws 3 as a support. A first object that is slidably fitted to the outer periphery of the fixed cylinder 5 in order in the outer diameter direction of the fixed cylinder 5 on the object side of the fixed cylinder 5 and supports the first lens group 7 and reciprocates along the optical axis. A sliding ring 9, an outer cylinder 13 fixed to the fixed cylinder 5 with screws 11, and a zoom ring 15 that rotates during zooming are provided.

  The cam ring 17 slidably fitted on the inner circumference of the fixed cylinder 5 and the second lens group 19 are slidably fitted on the inner circumference of the cam ring 17 in order in the inner diameter direction of the fixed cylinder 5. A second sliding ring 21 that moves along the optical axis, and a slidably fitted inner periphery of the fixed cylinder 5 on the inner side of the fixed cylinder 5, and the zoom ring 15 rotates to rotate the first sliding ring 9. Rotating rings 23 for transmitting to each other are arranged.

  A first zoom interlocking key 27 fixed to the zoom ring 15 with a screw 25 and transmitting the rotation of the zoom ring 15 to the cam ring 17 is fitted into a first key groove 29 provided on the image side of the cam ring 17, and the cam ring A second zoom interlocking key 33 that is fitted in a second key groove 31 provided on the object side 17 and transmits the rotation of the cam ring 17 to the rotating ring 23 is fixed to the rotating ring 23 with screws 35.

  The first sliding ring 9 is formed with a cam groove 9a and a rectilinear groove 9b. The first cam follower pin 37 fixed to the outer peripheral portion 5a of the fixed cylinder 5 is slidably engaged with the rectilinear groove 9b, and the rotation of the first sliding ring 9 is suppressed so that the first cam follower pin 37 moves straight along the optical axis. is doing. A sliding resistance reducing member 37a (for example, Delrin (registered trademark)) is disposed at a portion of the first cam follower pin 37 that contacts the groove wall of the rectilinear groove 9b. The second cam follower pin 39 fixed to the rotating ring 23 is slidably engaged with the circumferential groove 5b formed in the fixed cylinder 5 and the cam groove 9a, and the rotational force of the rotating ring 23 is applied to the first sliding force. It is transmitted to ring 9. A sliding resistance reducing member 39a (for example, Delrin (registered trademark)) is disposed at a portion of the second cam follower pin 39 that is in contact with the cam groove 9a and the circumferential groove 23a.

  The cam groove 9a is formed so that the projection axis with respect to the optical axis is inclined with respect to the optical axis. During zooming, the rotation of the zoom ring 15 is transmitted to the second cam follower pin 39 via the first zoom interlocking key 27, the cam ring 17, the second zoom interlocking key 33, and the rotating ring 23, and the second cam follower pin 39 is camped. When moving along the groove 9a, the first sliding ring 9 moves linearly along the optical axis because of the straight movement restriction by the first cam follower pin 37. Then, the first lens group 7 fixed to the first sliding ring 9 is moved to a predetermined position along the optical axis.

  A third cam follower pin 41 is fixed to the second sliding ring 21, and is slidably engaged with a cam groove 17 a formed in the cam ring 17 and a rectilinear groove 5 c formed in the fixed cylinder 5. A sliding resistance reducing member 41a (for example, Delrin (registered trademark)) is disposed at a portion of the third cam follower pin 41 that is in contact with the cam groove 17a and the rectilinear groove 5c.

  A fourth cam follower pin 43 is fixed to the cam ring 17 and is slidably engaged with a circumferential groove 5d formed in the fixed cylinder 5 so that the cam ring 17 rotates only in the circumferential direction along the optical axis. It is regulated not to move. A portion of the fourth cam follower pin 43 that contacts the circumferential groove 5d is provided with a sliding resistance reducing member 43a (for example, Delrin (registered trademark)).

  The cam groove 17a is formed such that the projection axis with respect to the optical axis is inclined with respect to the optical axis. When the rotation of the zoom ring 15 is transmitted to the cam ring 17 via the first zoom interlocking key 27 and the third cam follower pin 41 moves along the cam groove 17a, the straight movement is restricted by the straight movement groove 5c of the fixed cylinder 5, The second sliding ring 21 moves linearly along the optical axis. Then, the second lens group 19 fixed to the second sliding ring 21 is moved to a predetermined position along the optical axis.

  In the present embodiment, the screw hole 27a of the first zoom interlocking key 27 and the screw hole 33a of the second zoom interlocking key 33 are formed larger than the diameters of the fixing screws 25 and 35, respectively. The fixed position of the second zoom interlocking key 33 is formed to be adjustable. The screw holes 27a and 33a may be long holes other than round holes that are long in the rotation direction. Thus, the zoom lens barrel according to the embodiment of the present invention is configured.

  A method of assembling and adjusting the zoom lens barrel according to the embodiment of the present invention will be described with reference to FIG. Each member of the zoom lens barrel includes a processing error at the time of manufacture, and a deviation in the optical axis direction due to the processing error occurs when each member is assembled. This deviation in the optical axis direction deviates the positional relationship between the first lens group and the second lens group on the optical axis during zooming, and becomes a factor that deteriorates the imaging performance of the zoom lens. As an example, a displacement amount b in the optical axis direction caused by a displacement amount a in the rotation direction of the first sliding ring 9 occurs, and a displacement amount d in the optical axis direction due to a displacement amount c in the rotation direction of the cam ring 17. A method of assembling and adjusting the zoom lens barrel when it occurs will be described.

  In FIG. 3, each member of the zoom lens barrel is assembled according to an assembling procedure, and each screw is temporarily fixed. With the first zoom interlocking key 27 fitted in the first key groove 29 of the cam ring 17, the screws 25, 25 fixed to the zoom ring 15 are loosened to make the first zoom interlocking key 27 free. . The cam ring 17 is rotated so that the second lens group 19 is in the wide-angle end state position. When the second lens group 19 is positioned in the wide-angle end state position, the screws 25 and 25 are tightened and the first zoom interlocking key 27 is tightened. Is fixed to the zoom ring 15. By such adjustment, the shift amount d can be corrected.

  Next, with the second zoom interlocking key 33 fitted in the second key groove 31 of the cam ring 17, the screws 35, 35 fixed to the rotating ring 23 are loosened to release the second zoom interlocking key 33 free. Put it in a state. With the second lens group 19 fixed at the wide-angle end state position, the rotary ring 9 is rotated to move the first lens group 7, and the distance between the first lens group 7 and the second lens group 19 is the distance between the wide-angle end state. At this point, the screws 35 and 35 are tightened to fix the second zoom interlocking key 33 to the rotary ring 9. By such adjustment, the shift amount b can be corrected.

  By the assembly adjustment method as described above, it is possible to correct both the shift amounts b and d in the optical axis direction caused by processing errors, and it is possible to prevent the image formation performance of the zoom lens from deteriorating.

  Thus, in the zoom lens barrel according to the present invention, the screw holes 27a, 27a of the first zoom interlocking key 27 and the screw holes 33a, 33a of the second zoom interlocking key 33 are the diameters of the fixing screws 25, 35. Since it is formed larger, the fixed positions of the first zoom interlocking key 27 and the second zoom interlocking key 33 can be adjusted, and this is caused by the amount of displacement c or a in the rotational direction of the cam ring 17 or the rotating ring 9. The amount of deviation d or b in the optical axis direction can be corrected. As a result, it is possible to prevent deterioration of the imaging performance of the zoom lens. In addition, it is possible to relieve a defect that has been caused by a processing error of each member of the conventional zoom lens barrel, and to reduce the manufacturing cost.

  In the above-described embodiment, the description has been given of the case where each of the first zoom interlocking key and the second zoom interlocking key that can be adjusted in the rotation direction is provided. A plurality of two zoom interlocking keys may be arranged.

  The above-described embodiment is merely an example, and is not limited to the above-described configuration and shape, and can be appropriately modified and changed within the scope of the present invention.

1 is a partial cross-sectional view of a zoom lens barrel according to an embodiment of the present invention. 1 is a development view of a zoom lens barrel according to an embodiment of the present invention. It is a figure explaining the adjustment method of the zoom lens barrel concerning an embodiment of the invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Lens mount 3, 11, 25, 35 Screw 5 Fixed cylinder 7 1st lens group 9 1st sliding ring 13 Outer cylinder 15 Zoom ring 17 Cam ring 19 2nd lens group 21 2nd sliding ring 23 Rotating ring 27 1st 1 zoom interlocking key 29 1st keyway 31 2nd keyway 33 2nd zoom interlocking key 37 1st cam follower pin 39 2nd cam follower pin 41 3rd cam follower pin 43 4th cam follower pin

Claims (2)

A zoom ring to operate during zooming operation,
A plurality of moving groups that move in the direction of the optical axis as the zoom ring rotates;
A plurality of control rings for controlling the movement amounts of the plurality of movement groups;
At least one first interlocking member that interlocks at least one control ring and the zoom ring among the plurality of control rings;
Having at least one second interlocking member for interlocking the plurality of control rings;
The zoom lens barrel characterized in that the first interlocking member and the second interlocking member can be adjusted in position in a circumferential direction centering on the optical axis.   2. The zoom lens barrel according to claim 1, wherein the first interlocking member and the second interlocking member are elongated holes in which a fixing screw hole is long in a circumferential direction centering on an optical axis.

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