Camera with switching mechanism for selective operation of a retractable lens barrel and closeable lens barrier and method of operation

• US 5,461,441 A
• Filed: 06/10/1994
• Issued: 10/24/1995
• Est. Priority Date: 06/25/1993
• Status: Expired due to Term

• Current Assignee: Nikon Corporation
• Original Assignee: Nikon Corporation
• Inventors: Kotani, Noriyasu
• Primary Examiner(s): Adams, Russell E.
• Assistant Examiner(s): HAN, JANG K
• Application Number:
  US08/258,231
• Time in Patent Office: 501 Days
• Field of Search: 354/187, 354/195.1, 354/195.12, 354/202, 354/253, 354/288
• US Class Current: 396/349
• CPC Class Codes: G03B 17/04 collapsible, foldable or extensible, e.g. book type

Abstract

A camera uses a drive mechanism to scroll a lens barrel in and out of a camera body and to open and close a lens barrier that covers the front of the lens barrel. A spring is attached to the lens barrier, providing a spring force in the closing direction of the barrier and thereby preventing motion of the barrier in the opening direction of the barrier under an external force. A single electric motor is provided for driving a switching device, which includes a series of gears. The switching device switches power transmission of the motor between the lens barrel and the lens barrier, depending on the direction of rotation of the motor. Switching between scrolling in and out of the lens barrel and opening and closing of the lens barrier is possible only when the lens barrier can move in front of the lens barrel.

Claims

1. A camera, comprising:

a camera body having an opening;

a lens barrel movable between an extended position, in which the lens barrel protrudes through the opening in the camera body, and a withdrawn position, in which the lens barrel is withdrawn into the body;

a lens barrier movable between a closed position, in which the lens barrier covers the opening, and an open position, in which the lens barrier does not cover the opening;

a lens barrel drive coupled to the lens barrel to move the lens barrel between the extended position and the withdrawn position;

a lens barrier drive coupled to the lens barrier to move the lens barrier between the open position and the closed position;

a drive source for powering the lens barrel drive and the lens barrier drive;

a switching mechanism engaged with the drive source and selectively engageable with the lens barrel drive and with the lens barrier drive to cause the drive source to alternately power either the lens barrel drive or the lens barrier drive, the switching mechanism engaging the lens barrier drive to move the lens barrier from the open position toward the closed position only when the lens barrel drive has withdrawn the lens barrel through the opening into the body to an extent sufficient to prevent interference between the lens barrel and the lens barrier; and

a holding member coupled to the switching mechanism and holding the switching mechanism in engagement with the lens barrel drive when the lens barrel is in the extended position such that the drive source powers the lens barrel drive.

2. A camera according to claim 1, wherein:

the switching mechanism comprises at least one gear, the at least one gear being shiftable between a lens barrel driving position, in which the at least one gear engages the lens barrel drive, and a lens barrier driving position, in which the at least one gear engages the lens barrier drive;

the drive source powers the lens barrel drive through the at least one gear when the at least one gear is in the lens barrel driving position; and

the drive source powers the lens barrier drive through the at least one gear when the at least one gear is in the lens barrier driving position.

3. A camera according to claim 2, wherein:

the drive source alternately rotates the at least one gear in either of two opposed rotational directions; and

reversing the rotational direction of the drive source causes the at least one gear to shift between the lens barrel driving position and the lens barrier driving position.

4. A camera according to claim 2, wherein:

the at least one gear comprises a planetary gear;

the switching mechanism further comprises a solar gear engaged with the planetary gear; and

the planetary gear rotates about the solar gear as the planetary gear shifts between the lens barrel driving position and the lens barrier driving position.

5. A camera according to claim 2, wherein the holding member includes a locking mechanism engageable with the at least one gear to lock the at least one gear in the lens barrel driving position.

6. A camera according to claim 5, wherein the

holding member that selectively engages a shaft of the at least one gear to hold the at least one gear in the lens barrel driving position.

7. A camera according to claim 6, further comprising a release member connected to the lens barrel to cause the holding member to release the shaft as the lens barrel moves toward the withdrawn position, thereby allowing the at least one gear to shift toward the lens barrier driving position, wherein the release member causes the holding member to release the shaft only when the lens barrel is withdrawn through the opening into the body to an extent sufficient to prevent interference between the lens barrel and the lens barrier.

8. A camera according to claim 7, wherein the holding member includes a lever and the release member includes a cam, the cam engaging the lever to cause the lever to release the shaft.

9. A camera according to claim 7, wherein the release member rotates into engagement with the holding member as the lens barrel is withdrawn into the body.

10. A camera according to claim 1, wherein the drive source includes an electric motor.

11. A camera according to claim 1, wherein:

the drive source is drivable in two drive directions;

the drive source powers the lens barrel drive when the drive source is driven in one of the two drive directions;

the drive source powers the lens barrier drive when the drive source is driven in the other of the two drive directions; and

when the drive direction of the drive source is changed from said other drive direction to said one drive direction, the switching mechanism causes the drive source to change from powering the lens barrier drive to powering the lens barrel drive.

12. A camera according to claim 1, further comprising a spring coupled to the lens barrier and urging the lens barrier toward the closed position, wherein the spring absorbs forces external to the camera that tend to cause the lens barrier to move from the closed position toward the open position.

13. A camera according to claim 1, further comprising a release member for causing the holding member to release the engagement between the switching mechanism and the lens barrel drive.

14. A camera according, to claim 1, wherein the lens barrier drive comprises:

a rotatable lever having a curved surface, the rotatable lever linked to the lens barrier so that rotation of the rotatable lever causes the lens barrier to move between the open position and the closed position; and

a drive member engaged with and movable along the curved surface, the switching mechanism engageable with the drive member so that as the drive source powers the lens barrier drive, the drive member moves along the curved surface to rotate the rotatable lever and thereby move the lens barrier between the open position and the closed position.

15. A camera according to claim 1, wherein the lens barrier is rotatably mounted to rotate between the open position and the closed position.

16. A camera, comprising:

a camera body having an opening;

a lens barrel movable between an extended position, in which the lens barrel protrudes through the opening and extends out of the camera body, and a withdrawn position, in which the lens barrel is withdrawn into the camera body;

a lens barrier movable between a closed position, in which the lens barrier covers the opening, and an open position, in which the lens barrier does not cover the opening;

lens barrel drive means for moving the lens barrel between the extended position and the withdrawn position;

lens barrier drive means for moving the lens barrier between the open position and the closed position;

drive means for powering the lens barrel drive and the lens barrier drive;

switching means for selectively engaging the drive means with the lens barrel drive means and with the lens barrier drive means to cause the drive means to alternately power either the lens barrel drive means or the lens barrier drive means to move the lens barrier from the open position toward the closed position only when the lens barrel drive means has withdrawn the lens barrel through the opening into the body to an extent sufficient to prevent interference between the lens barrel and the lens barrier; and

locking means for locking the drive means in operative connection with the lens barrel drive means when the lens barrel is in the extended position, such that the drive means powers the lens barrel drive means.

17. A camera according to claim 16, wherein the switching means includes:

releasing means for causing the locking means to release the operative connection between the drive means and the lens barrel drive means when the lens barrel reaches a position in which the lens barrel will not interfere with movement of the lens barrier to the closed position.

18. A camera according to claim 16, further comprising biasing means for biasing the lens barrier in the closed position when the lens barrier is located in the closed position.

19. A method of operating a camera having a lens barrel movable between an extended position and a withdrawn position, and having a lens barrier movable between a closed position and an open position, comprising the steps of:

powering a lens barrel drive for the lens barrel from a drive source by engaging the lens barrel drive with a drive gear driven by the drive source;

locking the drive gear to the lens barrel drive;

driving the lens barrel from the extended position toward the withdrawn position with the lens barrel drive;

powering a drive for the lens barrier from the drive source by unlocking the lens barrel drive from the drive gear and engaging the lens barrier drive with the drive gear, the lens barrier drive powering step occurring only when the lens barrel has moved into the body to an extent sufficient to prevent interference between the lens barrel and the lens barrier; and

driving the lens barrier from the open position toward the closed position.

20. A method according to claim 19, wherein the drive gear is a planetary gear, and the lens barrier drive powering step includes the step of rotating the planetary gear about a solar gear.

21. A method according to claim 19, wherein the step of unlocking the lens barrel drive includes releasing a locking member that locks the drive gear to the lens barrel drive by rotating a release member coupled to the lens barrel into engagement with the locking member to disengage the locking member as the lens barrel moves into the withdrawn position.

22. A method according to claim 19, wherein the lens barrier drive powering step includes the step of reversing a drive direction of the drive gear.

23. A method of claim 19, further comprising biasing the lens barrier in the closed position when the lens barrier is located in the closed position.