ELECTROSTATIC ACTUATOR

• US 20090079296A1
• Filed: 11/18/2008
• Published: 03/26/2009
• Est. Priority Date: 05/18/2006
• Status: Active Grant

• Current Assignee: Alps Alpine Co., Ltd.
• Original Assignee: ALPS Electric Company Limited (Alps Alpine Co., Ltd.)
• Inventors: Takahashi, Isao
• Granted Patent: US 7,868,516 B2
• Time in Patent Office: Days
• US Class Current: 310/300
• CPC Class Codes: H02N 1/004 in which a body is moved along a path due to interaction with an electric field travelling along the path

Abstract

When a mover during moving is displaced in a direction (X2 direction) perpendicular to a moving direction, between a deformation pattern portion formed in stator-side electrodes of a stator and a deformation pattern portion formed in mover-side electrodes of the mover, a restoring force trying to return the mover toward a direction (X1 direction) opposite to the X2 direction acts on the mover. This makes it possible to prevent the mover from displacement, and consequently to provide an electrostatic actuator improved in the linear movability toward the moving direction.

Claims

1. An electrostatic actuator comprising:

a stator having a plurality of stator-side electrodes;

a mover having a plurality of mover-side electrodes; and

a drive signal generating portion supplying predetermined drive signals between the stator-side electrodes and the mover-side electrodes,

wherein the mover is moved toward a predetermined moving direction in a state of being opposed to the stator;

wherein, when a direction perpendicular to the moving direction is defined to be a widthwise direction, the stator-side electrodes and the mover-side electrodes are formed into a linear pattern or a band shaped pattern along the widthwise direction; and

both the stator-side electrodes and the mover-side electrodes have deformation patterns of a wavy shape or a mountain-and-valley shape at least in their portions;

wherein in the stator-side electrodes and the mover-side electrodes, the deformation patterns are provided at a plurality of places along the widthwise direction; and

a pitch dimension between deformation patterns mutually adjacent in the widthwise direction is formed larger at places away from a center line on the stator side and a center line on the mover side than at places nearer the center lines; and

wherein the stator-side electrodes and the mover-side electrodes are formed into the same pattern shape.

2. The electrostatic actuator according to claim 1, wherein, when an imaginary straight line extending toward the moving direction through a widthwise center of the stator is assumed to be a center line on the stator side, and an imaginary straight line extending toward the moving direction through a widthwise center of the mover is assumed to be a center line on the mover side, the stator-side electrodes are formed into shapes that are line-symmetric with respect to the center line on the stator side, and the mover-side electrodes are formed into shapes that are line-symmetric with respect to the center line on the mover side.

3. The electrostatic actuator according to claim 1, wherein the stator-side electrodes and the mover-side electrodes are both configured so that electrodes adjacent to each other along the moving direction are formed into the same pattern shape.

4. The electrostatic actuator according to claim 1, wherein at least the mover is formed into a thin sheet shape.

5. The electrostatic actuator according to claim 1, wherein drive signals having a three-phase alternating current shape are supplied between the stator-side electrodes and the mover-side electrodes, from the drive signal generating portion.