Electrostatically oscillated device

• US 7,276,834 B2
• Filed: 07/20/2006
• Issued: 10/02/2007
• Est. Priority Date: 03/12/2004
• Status: Expired due to Fees

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Higuchi, Hirofumi
• Primary Examiner(s): Williams, Hezron
• Assistant Examiner(s): BELLAMY, TAMIKO D
• Application Number:
  US11/489,682
• Publication Number:
  US 20060255694A1
• Time in Patent Office: 439 Days
• Field of Search: 734/88, 735/042, 735/044, 735/041.2, 735/141.6, 735/142.9, 310/308, 310/309, 361/127
• US Class Current: 310/309
• CPC Class Codes: G01C 19/5762 the sensing mass being connected to a driving mass, e.g. driving frames

Abstract

An oscillator is oscillatable in a predetermined direction. First and second driving electrodes are secured to the base and apply an electrostatic force to the oscillator to make drive oscillation of the oscillator in the predetermined direction. At the time of the drive oscillation of the oscillator, a predetermined electric charge is accumulated in the oscillator, and electric charges of opposite polarities are alternately and periodically accumulated in the first and second driving electrodes, respectively, to exert an attractive force between the oscillator and a corresponding one of the first and second driving electrodes and also to exert a repulsive force between the oscillator and the other one of the first and second driving electrodes, and vice versa.

Claims

1. An electrostatically oscillated device comprising:

a base;

an oscillator that is movable relative to the base, wherein the oscillator is oscillatable in a predetermined direction and includes first and second frames, which are arranged one after another in the predetermined direction;

first and second driving electrodes that are secured to the base and apply an electrostatic force to the oscillator to make drive oscillation of the oscillator in the predetermined direction, wherein;

the first and second driving electrodes are arranged on first and second sides, respectively, of the oscillator, which are opposed to each other in the predetermined direction;

the first driving electrode includes;

a primary driving electrode portion that is opposed to a first side outer peripheral portion of the oscillator in the predetermined direction;

a frame interior side securing portion that is secured to the base and extends from the primary driving electrode portion of the first driving electrode into the first frame; and

a secondary driving electrode portion that is provided to the frame interior side securing portion of the first driving electrode to oppose an inner peripheral portion of the first frame in the predetermined direction;

the second driving electrode includes;

a primary driving electrode portion that is opposed to a second side outer peripheral portion of the oscillator in the predetermined direction;

a frame interior side securing portion that is secured to the base and extends from the primary driving electrode portion of the second driving electrode into the second frame; and

a secondary driving electrode portion that is provided to the frame interior side securing portion of the second driving electrode to oppose an inner peripheral portion of the second frame in the predetermined direction;

at least one first driving electrode side dummy portion that is positional inside the first frame between the first side outer peripheral portion of the oscillator and the secondary driving electrode portion of the first driving electrode in the predetermined direction and has an electric potential that is in a floating state or is the same as that of the first frame; and

at least one second driving electrode side dummy portion that is positional inside the second frame between the second side outer peripheral portion of the oscillator and the secondary driving electrode portion of the second driving electrode in the predetermined direction and has an electric potential that is in a floating state or is the same as that of the second frame.

2. The electrostatically oscillated device according to claim 1, wherein:

the electric potential of the at least one first driving electrode side dummy portion is the same as that of the first frame;

the electric potential of the at least one second driving electrode side dummy portion is the same as that of the second frame; and

the electric potential of the first frame is the same as the electric potential of the second frame.

3. The electrostatically oscillated device according to claim 1, wherein:

the first frame has an opening, through which the frame interior side securing portion of the first driving electrode extends into an interior of the first frame; and

the second frame has an opening, through which the frame interior side securing portion of the second driving electrode extends into an interior of the second frame.