JP2000275496A - Replacement lens - Google Patents

Abstract

PROBLEM TO BE SOLVED: To permit smooth zooming actuation by preventing twisting resulting from a backlash in the fit between the zoom ring of a replacement lens and a fixed cylinder. SOLUTION: This replacement lens has a stepped anti-backlash piece 18 incorporated into a round hole 16b in a zoom ring 16 and into a circumferential groove 21b provided on the outer peripheral surface of a fixed cylinder 21 and corresponding to a zooming rotary angle. Thus, a zoom roller 15 integrated with a zoom key 14 secured to a cam cylinder 2 for bringing the required group of lenses into zooming movement is fitted into the round hole 16a in the zoom ring 16 to regulate the thrust of the zoom ring 16 and to prevent twisting that may be caused by a backlash in fitting between the fixed cylinder 21 and the zoom ring 16.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an interchangeable lens which can prevent a zoom or focus operation member (operation ring) from being twisted and can perform a smooth zoom operation and a manual operation.

[0002]

2. Description of the Related Art Conventionally, a zoom operation of a zoom lens is performed by rotating a cam ring by a cam follower of a lens moving frame fitted in a straight guide groove of a guide cylinder and a cam groove of a cam ring. When the (lens group) moves to a predetermined position on the optical axis, zooming is performed. Normally, the link between the cam ring and the zoom ring (zoom operating member) is such that a member called a zoom key or a zoom lever made of metal is attached to the cam ring with a screw or the like, and the other key is attached to the zoom ring via a screw or roller and linked. Things are common. Further, the zoom ring is fitted into a fixed barrel (fixed barrel), and thrust is regulated by another barrel or the like. Further, a zoom key and a zoom lever are provided with cutouts (holes) in a fixed frame for mounting on the zoom ring. Activate the zoom through that part.

[0003] However, in the above-mentioned structure, there is no problem in that the thrust restriction of the zoom ring is restricted by being sandwiched by another lens barrel or the like, or the thrust is restricted by bayonet coupling. In the case where thrust is restricted by the mounting roller, the zoom ring is tilted with respect to the fixed frame due to the looseness of the fixed frame and the zoom ring, causing a twist, and a smooth zoom operation cannot be obtained. Therefore, in order to solve this problem, a circumferential groove is provided in a fixed cylinder which is rotatable by fitting a zoom operation ring as a zoom operation member, and a cam ring and a zoom ring are formed by a zoom key as a transmission key. When one zoom key is used, two play frames are removed at approximately 120 ° intervals.
In the case of two zoom keys that act as a couple, one or two play-removing pieces are provided at approximately 90 ° in the direction opposite to the zoom key, and the play-removing pieces are fitted through the round holes of the zoom ring, and the circumference of the fixed cylinder is rotated. An interchangeable lens that regulates the thrust of a groove and a zoom ring together with a zoom key connecting roller is known.

[0004]

However, in the above-mentioned conventional example, a play-removing roller (play-removing piece) is fitted into the round hole of the zoom ring, and the play-removing roller is brought into contact with the circumferential groove of the fixed frame to thereby thrust. Although it is a restriction, the floating of the backlash removing roller is only covered with the zoom rubber, so the roller dances in the round hole of the zoom ring and securely contacts the circumferential groove. However, there was a problem that the effect of the play was reduced by half. In addition, there is a method of measuring a loosening roller, but it is a method of measuring two parts of a circumferential groove of a fixed frame of a round hole of a zoom ring, and the feasibility is low. Further, there is a method of bonding the backlash removing roller and the round hole of the zoom ring in a state where the backlash removing roller and the circumferential groove are securely brought into contact with each other. There was a disadvantage that it was not preferable.

The present invention eliminates the above-mentioned disadvantages of the prior art,
It is an object of the present invention to provide an interchangeable lens that can prevent a zoom ring from being fitted to a fixed cylinder due to fitting play and can perform a smooth zoom operation.

[0006]

To achieve the above object, the present invention provides an interchangeable lens for transmitting rotation of an operation member to a rotation member for moving a lens group via a transmission key. A stepped play is interposed between the member and a fixing member inside the member.

[0007]

According to a first aspect of the present invention, there is provided an interchangeable lens having a structure in which the rotational force of an operating member is transmitted to a rotating member by a transmission key, wherein the interchangeable lens is provided with a play removing piece inside the operating member. The play removing piece has a stepped shape in which a portion inserted into a round hole provided in the operation member and a portion abutting on a circumferential groove provided in a fixed frame into which the operation member is fitted are provided. In addition, it is possible to prevent the operation member from being twisted by the fitting play with the fixed frame, and to smoothly operate the lens barrel. According to the second aspect of the present invention, since the two or one play-removing pieces are provided, the play with the fixed frame can be removed, and the thrust of the operation member can be regulated stably. The present invention described in claim 3 is:
The stepped play is disposed from the inside of the operating member, and the operating member is incorporated in the fixed frame to prevent the operating member from coming off. Regulations can be performed stably.

According to a fourth aspect of the present invention, the operating member is a zoom ring, and the rotating member is a cam ring.
Thrust control of the zoom ring can be performed, and zoom operation via the cam ring can be performed smoothly. According to a fifth aspect of the present invention, a fixed groove in which a zoom ring as an operation member is fitted is provided with a circumferential groove corresponding to a zoom rotation angle, and the zoom ring is provided with a circular hole, and the circumferential groove and the circular groove are provided. Since the play ring is fitted into the round hole and the zoom ring is thrust-restricted, it can be prevented from being twisted by the fitting play with the fixed frame,
Smooth zoom operation can be obtained. According to a sixth aspect of the present invention, in the play removing piece, a fitting length abutting on a circumferential groove provided on the fixed frame is longer than a diameter of a round hole provided on the zoom ring. As a result, only one play-removing frame, which has been conventionally required, can be reduced to one.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a longitudinal sectional view of a zoom lens which is an interchangeable lens according to the present embodiment, FIG. 2 is a front view of a zoom-related component as viewed from a mount side, and FIG. In FIG. 1, 1 is a guide cylinder, 2 is a cam cylinder,
A first movable frame 3 for the first lens group, a second movable frame 4 for the second lens group, and a third movable frame 3 are rotatably fitted to the inner diameter of the guide cylinder 1. A third moving frame 5 for the lens group is slidably fitted in the optical axis direction. A cam follower 3a planted with screws or the like in the first moving frame 3 and a cam follower 4a planted with screws or the like in the second moving frame 4 (the cam follower of the third moving frame 5 is not shown) are provided. Linear guide grooves 1a and 1b provided in guide tube 1.
, Respectively, and further into the cam grooves 2a and 2b provided in the cam cylinder 2, respectively.

[0010] A cam follower 6a, which is implanted with a screw or the like in a holding frame 6 for holding a part of the lens L2 of the first lens group, is provided in an inner diameter portion of the first moving frame 3 in a cam groove of the first moving frame 3. 3b
A focus key 8 for directly transmitting the rotating power of a known ultrasonic motor 7 is fitted to a focus adjustment block 9 attached to the holding frame 6 with screws or the like. A holding ring 10 for holding a part of the lens L1 of the first lens group is screw-connected to the tip of the first moving frame 3. Further, a hood mounting ring 11 screwed to the guide cylinder 1 (not shown) is fixed to an outer peripheral portion of the holding ring 10,
A manual ring 12 is rotatably fitted around the outer periphery of the guide cylinder 1, and a manual rubber 13 is wound around the outer periphery of the manual ring 12.

Further, the cam cylinder 2 and the zoom ring 16 are connected by a zoom key 14 and a zoom roller 15 fixed to the cam cylinder 2 with screws. A zoom rubber 17 is wound around the outer periphery of the zoom ring 16,
A zoom brush 19 for a zoom encoder is fixed to the zoom key 14. On the other hand, a fixing cylinder 21 serving as a fixing frame to be connected to the mount 20 is screw-connected to a rear portion of the guide cylinder 1, and a mounting board 22 is disposed between the fixing cylinder 21 and the mount 20. Further, the zoom ring 16 is attached to the fixed cylinder 2.
The manual ring 12 is rotatably fitted to the outer periphery of the guide tube 1 by the zoom roller 15, and the manual ring 12 is rotatably fitted to the guide cylinder 1 by the zoom roller 15. The thrust is restricted by the end 7b of the communication ring 7a and the end 21a of the fixed cylinder 21. Further, a circumferential groove 21 provided on an outer peripheral portion of the fixed cylinder 21 is provided.
A step-shaped play removing piece 18 is fitted into the b and the round hole 16b provided in the inner peripheral portion of the zoom ring 16.

In this embodiment having the above structure, the holding frame 6 is also rotated by the rotation of the ultrasonic motor 7 or the manual ring 12, and is moved back and forth in the optical axis direction along the cam groove 3 b of the first moving frame 3. When the zoom ring 16 is rotated and the zoom ring 16 is rotated, the first moving frame 3 and the holding frame 6 are similarly guided by the cam groove 2a of the cam cylinder 2 and the straight guide groove 1a of the guide cylinder 1. Guided by the groove 2b and the straight guide groove 1b, the second moving frame 4 moves along the optical axis direction, and zooming is performed.

Next, the relationship between the stepped play frame 18 and the zoom-related parts will be described in detail. End face 7b of connecting ring 7a of ultrasonic motor 7 like manual ring 12
If the manual ring 12 is pinched between the guide tube 1 and the end surface 21a of the fixed tube 21, there is no problem that the manual ring 12 is twisted due to the looseness of the fitting with the guide tube 1. However, as in the present embodiment, the zoom ring 16 is mounted on the lens barrel. When the zoom ring 16 is located near 20, the thrust positioning behind the zoom ring 16 cannot be performed.
The thrust of the zoom ring 16 is restricted by the round hole 16a of the zoom ring 16 and the zoom roller 15, and the zoom ring 16 is rotated at a fixed position. In this case, the fitting play between the fixed cylinder 21 and the zoom ring 16 causes twisting.

FIG. 2 shows the relationship between the step-removing playpiece 18 and the zoom-related parts as viewed from the mount 20 direction.
As described above, the twisting of the zoom ring 16 occurs at a position in the direction of the arrow A shown in FIG. For this reason, a circumferential groove 21b having a zoom rotation angle + α is provided in the fixed cylinder 21, and the twist in the direction of the arrow A due to the fitting play is suppressed by the step-shaped play removing piece 18 and the circumferential groove 21b. Further, since the play removing piece 18 is formed in a stepped shape and is incorporated from the inner diameter side of the zoom ring 16, even if the play is performed, the play removing piece 18 does not float and stably fits in the circumferential groove 21b of the fixed cylinder 21. The thrust control of the zoom ring 16 is performed.

FIG. 3 is an enlarged perspective view of the stepped play backing piece 18, which has a circumferential groove 21b of the fixed cylinder 21 with respect to the diameter d of the pin portion 18b inserted into the round hole 16b of the zoom ring 16. By increasing the fitting length c of the base portion 18a abutting on the base member, stable play can be achieved,
One backlash removal frame, which was conventionally required at two positions approximately 90 ° opposite to the zoom key 14, may be replaced by one.

[0016]

As described above, according to the first aspect of the present invention, in the interchangeable lens having a structure in which the rotational force of the operating member is transmitted to the rotating member by the transmission key, the backlash is removed inside the operating member. The play removing piece has a stepped shape in which a portion inserted into a round hole provided in the operation member and a portion abutting on a circumferential groove provided in a fixed frame into which the operation member is fitted. By doing so, it is possible to prevent the operation member from being twisted due to looseness of the fitting with the fixed frame, and to smoothly operate the lens barrel. According to the second aspect of the present invention, since the play-removing pieces are provided with two or one, the play with the fixed frame can be removed, and the thrust of the operation member can be regulated stably. According to a third aspect of the present invention, the stepped play is disposed from the inside of the operation member, and the operation member is incorporated into the fixed frame to prevent the operation member from coming off, thereby controlling thrust of the operation member. Can be performed stably.

According to a fourth aspect of the present invention, the operating member is a zoom ring and the rotating member is a cam ring.
Thrust control of the zoom ring can be performed, and zoom operation can be performed smoothly. According to a fifth aspect of the present invention, a circumferential groove corresponding to a zoom rotation angle is provided in a fixed frame in which a zoom ring as a zoom operation member is fitted, and a round hole is provided in the zoom ring. When the play ring is inserted into the round hole and the zoom ring is thrust-restricted, the zoom ring can be prevented from being loose due to the loose fit of the zoom ring with the fixed frame, and the zoom operation can be performed smoothly. According to a sixth aspect of the present invention, in the play removing piece, a fitting length abutting on a circumferential groove provided on the fixed frame is longer than a diameter of a round hole provided on the zoom ring. As a result, a stable play can be obtained, and the play-removing frame, which is conventionally required two, can be reduced to one.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a zoom lens which is an interchangeable lens according to an embodiment of the present invention.

FIG. 2 is a front view of a zoom-related component as viewed from its mount side.

FIG. 3 is an enlarged perspective view of the play removing frame.

[Explanation of symbols]

1 ··· Guide tube, 2 ·· Cam tube, 3 ··· First moving frame, 4 ·
・ Second moving frame, 5 ・ 3rd moving frame, 6 ・ ・ Holding frame, 7 ・
-Ultrasonic motor, 8-Focus key, 9-Focus adjustment block, 12-Manual ring, 14-Zoom key, 15-Zoom roller, 16-Zoom ring, 16a, 16b-Round hole, 18-・ Stepped play, 19 ・ ・ Zoom brush, 20 ・ Mount,
21: fixed cylinder, 21b: circumferential groove, 22: mounting board.

Claims (6)

[Claims] 1. An interchangeable lens having a structure in which the rotational force of an operating member is transmitted to a rotating member by a transmission key, wherein a play removing frame is provided inside the operating member, and the play removing frame is provided on the operating member. An interchangeable lens, wherein a portion inserted into a round hole and a portion abutting on a circumferential groove provided in a fixed frame into which the operation member is fitted have a stepped shape. 2. The interchangeable lens according to claim 1, wherein said play removing frame includes two or one. 3. The step-shaped play removing piece is provided from the inside of the operation member, and the operation member is incorporated into the fixed frame to prevent the operation member from falling off. interchangeable lens. 4. The apparatus according to claim 1, wherein said operating member is a zoom ring, and said rotating member is a cam ring.
The interchangeable lens described. 5. A fixed frame in which a zoom ring as an operation member fits is provided with a circumferential groove corresponding to a zoom rotation angle,
5. The zoom ring according to claim 1, wherein the zoom ring is provided with a round hole, and a play removing piece is fitted into the circumferential groove and the round hole to regulate the thrust of the zoom ring. interchangeable lens. 6. The backlash piece has a longer fitting length in contact with a circumferential groove provided in the fixed frame than a diameter of a round hole provided in the zoom ring. Claim 1
6. The interchangeable lens according to 5.