JP3062957B2 - Camera mount lock device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lock device for a mount which is a detachable portion of a single-lens reflex camera, and more particularly to a lock device in which a lock play of a mount is eliminated.

[0002]

2. Description of the Related Art As an attachment / detachment device for a camera body and an interchangeable lens, when a positioning engagement portion comes to a predetermined position, a spring-biased positioning member protrudes into a positioning recess and engages therewith. Japanese Utility Model Publication No. Sho 53-50420 proposes a lens lock device in which the engagement between the positioning member and the positioning concave portion is released in accordance with the disengagement operation. In addition, between the positioning member and the positioning recess, or between the front end of either side surface and the engaging portion, a non-contact portion having a small gradient on the front end side and a large gradient on the engaging portion side is formed. Japanese Patent Application Laid-Open No. 61-320 discloses a camera which ensures the engagement between the camera body and the interchangeable lens.
42.

[0003]

In a single-lens reflex camera mount, there is some backlash in the mount portion. The play in the mount is due to the clearance required for mounting the mount, but it is desirable that the play be small in precision equipment such as a single-lens reflex camera. The types of play of the mount portion include radial play, front-back play, and rotational play. The play in the radial direction is due to the gap between the spigot portions of the mount, the play in the front-rear direction is due to the gap between the pawl of the bayonet and the groove of the bayonet, and the play in the rotational direction is due to the gap between the lock groove and the lock pin. When a heavy lens such as a large-aperture lens or a super-telephoto lens is attached, the user feels backlash in the vertical direction of the mount, and when performing operations in the rotation direction such as focusing and zooming, the user feels backlash in the radial direction.

A lock groove is provided in one of a camera mount and a lens mount which can be rotated relative to each other by a fixed angle, and a lock member is provided in the other mount so as to be detachable from the lock groove. As shown in FIG. 5, a lock groove 43 provided on a mount surface 42 of a lens mount 41,
Since the clearance 設 け is provided between the camera mount 51 and the lock pin 53 protruding from the mount surface 52, there is a problem that play in the rotation direction occurs.

[0005]

SUMMARY OF THE INVENTION According to the present invention, a lock groove is provided on one of a camera mount and a lens mount which can be rotated relative to each other by a fixed angle, and a lock member is provided on the other mount which can be disengaged from the lock groove. In the mount to fix the mount by this lock groove and the lock member,
By providing the inner diameter of the lock groove with an inclination, the problem that the play in the rotation direction occurs is solved.

[0006]

When the inner diameter of the lock groove is inclined, the tip of the lock member is fixed by the inclination of the inner diameter of the lock groove, and there is a function of eliminating play in the rotation direction of the camera mount and the lens mount.

[0007]

EXAMPLES Examples of the present invention will be described below.

FIGS. 2 and 3 are front views showing a lens mount and a camera mount of the lock device of the present invention.

In FIG. 2, reference numeral 11 denotes a lens mount.
On the inner peripheral side of the mounting surface 12, three bayot claws 14a, 1
4b and 14c are formed. A lock groove 13 is formed in a left peripheral area of the mount surface 12.

In FIG. 3, reference numeral 21 denotes a camera mount,
Bayonet claws 14a, 14b, 1 of lens mount 11
4c respectively engaging with three bayonet claws 24a,
24 b and 24 c are formed on the inner peripheral surface of the mount surface 22. A lock pin 23 is arranged on the right peripheral area of the mounting surface 22. As shown in FIG. 4, the lock pin 23 is urged in the optical axis direction from the mount surface 12 of the lens mount 11 by a spring 32 to protrude therefrom.
It is engaged with one lock groove 13.

FIG. 4 is a sectional view showing a locked state of the lens mount and the camera mount. When the release button 31 is pressed, the lock pin 23 is retracted from the lock groove 13 to the inside of the mount surface 22 to release the locked state.

FIG. 1 is a sectional view showing the relationship between a lock groove and a lock pin of a mount lock device for a camera according to the present invention.

Reference numeral 11 denotes a lens mount, and 21 denotes a camera mount. The lens mount 11 is provided with a circular lock groove 13, and the lock groove 13 has an inclined portion 15 so that the diameter decreases as the depth increases from the diameter 13 a of the mount surface 12. A columnar lock pin 23 is engaged with the camera mount 21 by projecting into the lock groove 13 of the lens mount 11 by a spring (not shown). The lock groove 13 of the lens mount 11 is provided with an inclined portion 15, and the deepest diameter 13 b of the lock groove 13 is smaller than the diameter 23 a of the lock pin 23 of the camera mount 21. The clearance of the lock pin 23 is lost.

[0014]

According to the present invention, by providing the inner diameter of the lock groove with an inclination, the tip of the lock member is fixed by the inclination of the inner diameter of the lock groove. Even a heavy lens with such a weight can suppress mount play.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an engagement state of a mount lock device for a camera according to the present invention.

FIG. 2 is a front view showing a lens mount.

FIG. 3 is a front view showing a camera mount.

FIG. 4 is a cross-sectional view showing a locked state of a lens mount and a camera mount.

FIG. 5 is a cross-sectional view showing an engagement state of a mount lock device of a conventional camera.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Lens mount 13 Lock groove 15 Inclined part 21 Camera mount 23 Lock pin

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G03B 17/12-17/14 G03B 17/56 G03B 17/02 G02B 7/02-7/16 F16B 7 / 00-7/22 F16B 21/12-21/14

Claims (1)

(57) [Claims] 1. A circular lock groove is mounted on one of a camera mount and a lens mount that can be relatively rotated at a fixed angle, and the other mount is detachable from the lock groove.
In a camera mount in which a columnar lock member is provided and the mount is fixed by the lock groove and the lock member, the diameter of the deepest part of the lock groove is made smaller than the diameter of the lock member by providing an inclination in the circular lock groove. A lock device for a camera mount, characterized in that it is made smaller.