Electromagnetically actuated shutter for a camera

• US 4,634,254 A
• Filed: 06/20/1985
• Issued: 01/06/1987
• Est. Priority Date: 06/25/1984
• Status: Expired due to Term

• Current Assignee: Seiko Precision Incorporated (Seiko Group)
• Original Assignee: Seiko Koki Kabushiki Kaisha
• Inventors: Sato, Koji, Ishida, Hiroaki, Nagaoka, Shinji, Ogihara, Masuo
• Primary Examiner(s): Perkey, William B.
• Application Number:
  US06/747,015
• Time in Patent Office: 565 Days
• Field of Search: 354/400, 354/402-405, 354/412, 354/439, 354/456, 354/195.1, 354/234.1, 354/436, 354/437
• US Class Current: 396/132
• CPC Class Codes: G03B 3/10 Power-operated focusing
• CPC Class Codes: G03B 7/085 for control of aperture

Abstract

An electromagnetically actuated shutter for a camera wherein automatic focusing and exposing operation are controlled by means of a single reversible stepping motor.

Claims

1. An electromagnetically actuated shutter, comprising:

a movable member mounted for movement in forward and reverse directions between a focusing region and an exposing operation region;

a single electromagnetic actuating means for forwardly and reversely actuating said movable member;

an interlocking member mounted to undergo movement with said movable member in said focusing region;

a focus operating member actuated by forward movement of said interlocking member to effect an automatic focusing operation;

a focusing control member engageable with said interlocking member to stop the forward movement thereof when said movable member moves through said focusing region and reaches a focusing point;

shutter blades driven by a sector lever when said movable member undergoes movement in said exposing operation region; and

controlling means operable in response to movement of said movable member into said exposing operation region for producing a reversing signal and applying the same to said electromagnetic actuating means after the lapse of a time corresponding to object brightness information to thereby cause said electromagnetic actuating means to move said movable member in the reverse direction.

2. In a camera shutter having a set of shutter blades sequentially movable in opening and closing directions to define an exposure interval:

an actuating member mounted to sequentially undergo forward movement in a forward direction through a focusing region and an exposure region followed by return movement in a return direction through the exposure and focusing regions;

means operative in response to forward movement of the actuating member in the focusing region to effect an automatic focusing operation;

means operative in response to forward movement of the actuating member in the exposure region to effect opening movement of the set of shutter blades and operative in response to return movement of the actuating member in the exposure region to effect closing movement of the set of shutter blades; and

electromagnetic driving means for sequentially driving the actuating member in the forward direction through the focusing and exposure regions and then in the return direction through the exposure and focusing regions.

3. A camera shutter according to claim 2;

including control means operative in response to forward movement of the actuating member in the exposure region for producing an output signal after the lapse of a time interval corresponding to the brightness of an object being photographed; and

wherein the electromagnetic driving means includes means responsive to the output signal for commencing driving of the actuating member in the return direction.

4. A camera shutter according to claim 3, wherein the electromagnetic driving means comprises a stepping motor rotatable in forward and reverse directions of rotation, and means responsive to the forward and reverse rotations of the stepping motor for accordingly driving the actuating member in the forward and return directions.

5. A camera shutter according to claim 2;

wherein the actuating member comprises a linearly displaceable member.

6. A camera shutter according to claim 2;

wherein the means to effect an automatic focusing operation comprises an interlocking member mounted to undergo forward and return movements together with the actuating member in the focusing region, and means releasably engageable with the interlocking member to arrest the forward movement thereof at the completion of the automatic focusing operation while permitting the actuating member to continue its forward movement.

7. A camera shutter according to claim 6;

including control means operative in response to forward movement of the actuating member in the exposure region for producing an output signal after the lapse of a time interval corresponding to the brightness of an object being photographed; and

wherein the electromagnetic driving means includes means response to the output signal for commencing driving of the actuating member in the return direction.

8. A camera shutter according to claim 2, wherein the actuating member comprises an angularly displaceable member.

9. In a camera shutter having automatic focusing means operative when actuated to effect an automatic focusing operation, and automatic exposure means including a set of shutter blades operative when sequentially actuated in opening and closing directions to effect an automatic exposure operation:

actuating means displaceable in a forward direction to sequentially actuate the automatic focusing means and thereafter actuate the shutter blades in the opening direction and then displaceable in a return direction to actuate the shutter blades in the closing direction; and

electromagnetic driving means for sequentially displacing the actuating means in the forward and return directions.

10. A camera shutter according to claim 9;

wherein the electromagnetic driving means comprises a stepping motor rotatable in forward and reverse directions of rotation, and means responsive to the forward and reverse rotations of the stepping motor for accordingly displacing the actuating means in the forward and return directions.

11. A camera shutter according to claim 10;

wherein the actuating means comprises linearly displaceable actuating means mounted to undergo linear displacement in the forward and return directions.

12. A camera shutter according to claim 11;

including an interlocking member mounted to undergo forward and return displacements together with the actuating means, and means releasably engageable with the interlocking member to arrest the forward displacement thereof at the completion of the automatic focusing operation while permitting the actuating means to continue its forward displacement.

13. A camera shutter according to claim 10;

wherein the actuating means comprises angularly displaceable actuating means mounted to undergo angular displacement in the forward and return directions.

14. A camera shutter according to claim 13;

including an interlocking member mounted to undergo forward and return displacements together with the actuating means, and means releasably engageable with the interlocking member to arrest the forward displacement thereof at the completion of the automatic focusing operation while permitting the actuating means to continue its forward displacement.

15. A camera shutter according to claim 9;

wherein the actuating means comprises linearly displaceable actuating means mounted to undergo linear displacement in the forward and return directions.

16. A camera shutter according to claim 15;

including an interlocking member mounted to undergo forward and return displacements together with the actuating means, and means releasably engageable with the interlocking member to arrest the forward displacement thereof at the completion of the automatic focusing operation while permitting the actuating means to continue its forward displacement.

17. A camera shutter according to claim 9;

wherein the actuating means comprises angularly displaceable actuating means mounted to undergo angular displacement in the forward and return directions.

18. A camera shutter according to claim 17;

including an interlocking member mounted to undergo forward and return displacements together with the actuating means, and means releasably engageable with the interlocking member to arrest the forward displacement thereof at the completion of the automatic focusing operation while permitting the actuating means to continue its forward displacement.