JPH07159856A - Lens barrier device for camera - Google Patents

Abstract

PURPOSE:To provide a lens barrier for a camera capable of smoothly driving a barrier and shortening a retracting stroke, in the opening/closing actions of the lens barrier by making use of a retractive action, in a camera having a retractive lens barrel. CONSTITUTION:In the lens barrier device for the camera moving the lens barrel forward and backward with respect to a camera main body by the forward and backward rotations of a cam barrel 1 and simultaneously opening/closing the barrier covering the front surface of the lens group of a front part in the retractive system lens barrier for moving a lens to a fixed position, so as to be opened/closed, linked with the forward/backward rotations of a barrier ring 5, a connecting shaft 10 transmitting rotational force to the barrier ring 5 by using cam means 2 and 10a is rotated/driven by the forward/backward rotations in the retracting action region of the cam barrel 1, to open/close the barrier.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens barrier device for a camera provided on the front surface of a lens for protecting a taking lens.

[0002]

2. Description of the Related Art FIG. 8 shows a conventional lens barrier device, which includes a barrier ring 10 for rotating a barrier (not shown).
FIG. 5 is a cross-sectional view showing a transmission unit which is interlocked with 5, and this lens barrel is of a retractable type that advances and retracts with respect to the camera body.

In FIG. 8, 110 is a barrier ring 10.
5, which is a transmission member for transmitting a rotational force to the lens barrel 5, is provided with a hole 104a provided in the lens barrel cover 104, the lens barrel cover 104, and the rear base plate 11
4, the opening / closing lever 111 having a gear portion on the outer periphery is fixed to the press-fitting portion 110b, the gear portion of the opening / closing lever 111 meshes with the barrier gear 112, and the barrier gear 112
Mesh with the barrier ring 105. Lens barrel cover 10
Reference numeral 4 denotes a cover for covering the lens group 115, which is the lens group 115.
Does the same movement as. The cam barrel 10 is driven by a driving means (not shown).
When 1 rotates counterclockwise, the lens barrel cover 104 moves (collapses) toward the camera body along the optical axis along the cam provided on the cam barrel 101. Then the connecting shaft 110
The operating portion 110a provided at the rear end of the connecting shaft 1 slides along the tapered surface 103c provided on the rectilinear barrel 103,
10 rotates counterclockwise, and the opening / closing lever 1
The barrier ring 105 is rotated counterclockwise via the barrier gear 112 to close the barrier.

[0004]

However, in the above-mentioned conventional example, when the lens barrel cover 104 moves toward the camera body along the optical axis during the barrier closing operation, the rectilinear barrel 103 is used.
Since the operating portion 110a of the continuous shaft 110 slides on the tapered surface 103 provided on the connecting shaft 110 to rotate the connecting shaft 110, the barrier close failure due to the twisting of the connecting shaft 110, the operating load increases, and the barrel retracting stroke becomes longer. There was a drawback.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a lens barrier device for a camera that solves such a conventional problem.

[0006]

SUMMARY OF THE INVENTION A structure for achieving the object of the present invention is a retractable lens mirror for moving a lens to a predetermined position while advancing and retracting a lens barrel with respect to a camera body by forward and reverse rotations of a cam barrel. In a lens barrier device for a camera, which opens and closes a barrier that covers the front surface of a front lens group in a barrel so as to be openable and closable, in a lens barrier device of a camera, a forward and reverse rotation in a collapsing operation region of the cam barrel is cammed. It is characterized in that a transmission member for transmitting a rotational force to the barrier drive member is rotationally driven by means to open and close the barrier.

[0007]

1 to 7 show a first embodiment of the present invention. 1 is a front view showing a barrier open state, FIG.
Is a cross-sectional view showing a transmission part that works with the barrier ring of FIG.
3 is a front view showing a closed state of the barrier, FIG. 4 is a cross-sectional view showing a transmission portion interlocking with the barrier ring of FIG. 3, FIG.
FIG. 6 is a development view showing the relationship between the triangular ring and the transmission member (connecting shaft) when the barrier is open, and FIG. 7 is a triangle ring when the barrier is closed. It is a development view showing the relation of a transmission member (connection shaft).

In FIGS. 1 to 7, reference numeral 1 denotes a cam barrel, a gear portion 1a is formed on the outer peripheral portion in conjunction with driving means (not shown), and lens groups 15 and 16 are provided on the inner peripheral portion of the camera body. Cams 1b and 1c for advancing and retracting are formed, and a shaft hole 1d fixedly fitted to the shaft 2d of the triangular ring 2 is provided. Reference numeral 2 denotes a triangular ring, which is a vertical wall that drives the actuating portion 10a provided at the rear end of the connecting shaft 10 when closing the barrier with the cams 2a and 2b having the same curve as the cams 1b and 1c provided on the cam barrel 1. 2c is provided at a part of the cam 2b. Furthermore, during the barrier closing operation, the triangular ring 2 and the cam barrel 1
A shaft 2d for integrally rotating the shaft is fixedly fitted to the shaft hole 1d. By combining the cam barrel 1 and the triangular ring 2, a cam groove as shown in FIG. 5 is formed. Further, the cam barrel 1 is rotatably mounted on the outer periphery of the rectilinear barrel 3 with the triangular ring 2 assembled.

Reference numeral 3 denotes a straight-moving barrel, which is provided with six straight-moving cams 3a for moving the lens groups 15 and 16 straight in the optical axis direction. 3b is provided.

Reference numeral 4 denotes a lens barrel cover for covering the lens group 15, and a hole 4a, a barrier gear shaft 4b, a central opening 4c and a barrier shaft 4d, into which the press-fitting portion 10b of the connecting shaft 10 is rotatably fitted, are provided at the tip end portion. And a barrier ring spring 4e. Reference numeral 5 denotes a barrier ring arranged at the tip end portion, which is rotatably arranged around the central opening 4c, and is provided in the barriers 6 and 7. The engaging groove portion 5a engaged with the dowels 6a and 7a and the barrier spring 8 are provided. Gears 5d that rotate the barrier ring 5 in conjunction with the uprights 5b and 5c for hanging the barrier gear 12
And a vertical bending portion 5e for hanging the barrier ring spring 9 is provided. Barriers 6 and 7 cover the front surface of the lens and are rotatably fitted to the barrier shaft 4d. Dowels 6a and 7a rotate the barrier following the rotation of the barrier ring 5, and are brought into contact with one wall of the engaging groove 5a by the spring force of the barrier spring 8. Reference numeral 8 denotes a barrier spring, which is configured to bring the dowels 6a and 7a provided on the barriers 6 and 7 into contact with one wall of the engagement groove portion 5a, and to which the outer diameters of the barriers 6 and 7 which are fitted with the barrier shaft 4d. And the other ends are hooked on the upright portions 5b and 5c provided on the barrier ring 5, and the other ends are hooked on dowels 6a and 7a provided on the barriers 6 and 7, respectively.

Reference numeral 9 denotes a barrier ring spring, which urges the barrier ring 5 in the counterclockwise direction (barrier opening direction), one end of which is on the upright portion 5e provided on the barrier ring 5 and the other end of which is on the lens barrel cover 4. The barrier ring shafts 4e are respectively hung on the planted barrier ring shafts 4e.

Reference numeral 10 denotes a connecting shaft, which is formed in an L-shape and is rotatably fitted between the hole 4a provided in the lens barrel cover 4, the lens barrel cover 4 and the rear base plate 14, The actuating portion 10a at the end contacts the vertical wall 2c of the triangular ring 2, and the opening / closing lever 11 is press-fitted into the press-fitting portion 10b on the tip end side.

Reference numeral 11 denotes an opening / closing lever, which rotates in the same manner as the connecting shaft because it is pressed into the connecting shaft 10. Reference numeral 11a is a gear portion that meshes with the barrier gear 12. Reference numeral 12 denotes a barrier gear, which is rotatably fitted to a barrier gear shaft 4b embedded in the barrel cover 4. A lens barrel decorative plate 13 covers the front surfaces of the barriers 6 and 7 and is fixed to the lens barrel cover. Reference numeral 14 is a rear base plate, and 15 and 16 are lens groups.

Next, in the above structure, when closing the barrier, the main SW of the camera is turned off,
The cam cylinder 1 is rotated clockwise by a driving means (not shown),
The triangular ring 2 also rotates clockwise. Then, the vertical wall 2c provided on the triangular ring 2 causes the operating portion 1 of the connecting shaft 10 to move.
0a, and the cam barrel 11 rotates clockwise,
When the operating portion 10a is pushed by the vertical wall 2c, the connecting shaft 10 rotates in the clockwise direction, and at the same time, the opening / closing lever 11 press-fitted in the press-fitting portion 10b rotates in the clockwise direction, and the gear portion 11
The barrier gear 12 meshing with a rotates counterclockwise.

When the barrier gear 12 rotates counterclockwise, the barrier ring 5 pushes the dowels 6a, 7a against the spring force of the barrier ring spring 9 around the opening 4c by one wall of the engaging groove 5a. While rotating clockwise. Then, the barriers 6 and 7 rotate counterclockwise around the barrier axis 4d, and the barriers are closed as shown in FIGS.
During these operations, the lens groups 15 and 16 are retracted along the cams 1b and 1c provided on the cam barrel 1.

On the other hand, when the barrier is opened, by turning on the main SW of the camera, the cam cylinder 1 is rotated counterclockwise by the driving means (not shown), the triangular ring 2 is also rotated counterclockwise, and the vertical wall is rotated. Connecting shaft 10 charged with 2
Of the barrier ring 5, the barrier 6, and the barrier 6, due to the spring force of the barrier ring spring 9.
7, the connecting shaft 1 via the barrier gear 12 and the opening / closing lever 11
0 rotates counterclockwise, opening the barrier as shown in FIGS. During these operations, the lens groups 15, 1
6 is extended along the cams 1b and 1c provided on the cam barrel 1.

[0017]

As described above, according to the present invention, when the lens barrel is retracted, the transmission member rotates in association with the rotation of the cam barrel,
Since the barrier is closed, the barrier closing failure due to the twist of the transmission member and the operating load are reduced, and the barrel retracting (storage) stroke can be shortened, and a compact camera can be realized.

[Brief description of drawings]

FIG. 1 is a front view showing a barrier open state according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a transmission unit that works with the barrier ring of FIG. 1 in the first embodiment of the present invention.

FIG. 3 is a front view showing a closed state of the barrier according to the first embodiment of the present invention.

FIG. 4 is a cross-sectional view showing a transmission unit that works with the barrier ring of FIG. 3 in the first embodiment of the present invention.

FIG. 5 is a development view showing a cam shape in the first embodiment of the present invention.

FIG. 6 is a development view showing the relationship between the triangular ring and the transmission member in the barrier open state in the first embodiment of the present invention.

FIG. 7 is a development view showing the relationship between the triangular ring and the transmission member when the barrier is closed according to the first embodiment of the present invention.

FIG. 8 is a cross-sectional view showing a transmission unit that interlocks with a barrier ring in a conventional example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Cam tube 2 ... Triangular ring 2c ... Vertical wall 3 ... Straight tube 3b ... Groove 4 ... Lens tube cover 4a ... Hole 5 ... Barrier ring 6,7 ... Barrier 8 ... Barrier spring 9 ... Barrier spring 10 ... Connection shaft 10a ... Operating part 11 ... Opening / closing lever 12 ... Barrier gear 14 ... Rear base plate 15, 16 ... Lens group

Claims (1)

[Claims] 1. A front surface of a front lens group of a retractable lens barrel that moves a lens forward and backward with respect to a camera body by rotating the cam barrel forward and backward to open and close. In a lens barrier device for a camera that opens and closes a barrier in conjunction with normal and reverse rotations of a barrier drive member, forward and reverse rotations in a collapsing operation region of the cam barrel are transmitted to the barrier drive member by using cam means. A lens barrier device for a camera, wherein a transmission member is rotationally driven to open and close the barrier.