Image stabilizing actuator and camera furnished therewith

• US 20080231955A1
• Filed: 03/12/2008
• Published: 09/25/2008
• Est. Priority Date: 03/20/2007
• Status: Abandoned Application

• Current Assignee: Tamron Company Limited
• Original Assignee: Tamron Company Limited
• Inventors: Otsuka, Hiroshi
• Application Number:
  US12/073,937
• Publication Number:
  US 20080231955A1
• Time in Patent Office: Days
• US Class Current: 359/557
• CPC Class Codes: G02B 27/646 compensating for small deviations, e.g. due to vibration or shake movement of one or more optical elements for control of motion blur in cameras, projectors or printers G03B2205/0007; image stabilisation in cameras peculiar to the presence or use of an electronic image sensor H04N23/68

Abstract

Problem: To provide an actuator capable of preventing damage to spherical bodies and their receiving surfaces when subjected to a shock force.

Solution Means: The present invention is an actuator (10) for stabilizing images by moving an imaging lens, comprising a fixed portion (12), a movable portion (14) to which an imaging lens is attached, a plurality of spherical bodies (18) for supporting the movable portion, a fixed portion spherical body receiving surface (28b) disposed on the fixed portion and contacting the spherical bodies, a movable portion spherical body receiving surface (30b) disposed on the movable portion and contacting the spherical bodies, a biasing means (26) for sandwiching the spherical bodies between the fixed portion spherical body receiving surface and the movable portion spherical body receiving surface, and spherical body receiving surface protection means (29, 30) which, when image stabilization control is not in effect, reduce the contact pressure acting on the spherical bodies so as to sandwich the spherical bodies when the movable portion is moved to a predetermined protected position.

Claims

1. An actuator for moving an imaging lens within a plane perpendicular to its optical axis to prevent image blurring, the actuator comprising:

a fixed portion;

a movable portion to which the imaging lens is attached;

a plurality of spherical bodies supporting the movable portion in such a way that it can move on a plane parallel to the fixed portion;

a drive means for driving the movable portion with respect to the fixed portion;

a fixed portion spherical body receiving surface disposed on the fixed portion and contacting the spherical bodies;

a movable portion spherical body receiving surface disposed on the movable portion and contacting the spherical bodies;

a biasing means for generating a biasing force to cause the movable portion and the fixed portion to approach one another to sandwich the spherical bodies between the fixed portion spherical body receiving surface and the movable portion spherical body receiving surface; and

a spherical body receiving surface protection means to reduce contact pressure acting on the spherical bodies to sandwich the spherical bodies when the movable portion is moved to a predetermined protected position and not under image stabilization control.

2. The actuator according to claim 1, the spherical body receiving surface protection means comprising protuberances formed on the movable portion and the fixed portion, the protuberances contacting one another when the movable portion is moved to the protected position, thereby widening the gap between the fixed portion spherical body receiving surface and the movable portion spherical body receiving surface.

3. The actuator according to claim 2, wherein the protuberance is provided with a protuberance sloped surface, formed to connect to the top surface thereof, so that the movable portion is moved to the protected position as it slides on the protuberance sloped surface to widen the gap between the fixed portion spherical body receiving surface and the movable portion spherical body receiving surface.

4. The actuator according to claim 1, wherein the spherical body receiving surface protection means comprises a spherical body escape concavity formed in such a way that the spherical body escape concavity connects to at least either the fixed portion spherical body receiving surface or the movable portion spherical body receiving surface, and the spherical bodies are moved to the spherical body escape concavity when the movable portion is moved to the protected position, placing the fixed portion and the movable portion in direct mutual contact.

5. The actuator according to claim 1, wherein the spherical body receiving surface protection means comprises a protected position biasing means for biasing the movable portion toward the protected position, and load sharing surfaces respectively provided on the fixed portion and the movable portion, and wherein the load sharing surfaces are pushed against one another by means of a biasing force from the protected position biasing means.

6. The actuator according to claim 1, wherein the spherical body receiving surface protection means comprise a spherical body support surface portion formed to connect with at least one of the movable portion spherical body receiving surface and the fixed portion spherical body receiving surface, wherein the spherical body support surface portion contacts the spherical body when the movable portion is moved to the protected position, and wherein the contact surface area between the spherical body support surface portion and the spherical body is greater than the contact surface area between the fixed portion spherical body receiving surface or the movable portion spherical body receiving surface and the spherical body.

7. A camera, comprising:

a lens barrel;

a plurality of imaging lenses housed within the lens barrel;

the actuator according to claim 1 wherein at least one of these imaging lenses is attached to the movable portion; and

a camera main body.