DRIVE DEVICE AND IMAGE STABILIZER

• US 20090002500A1
• Filed: 06/25/2008
• Published: 01/01/2009
• Est. Priority Date: 06/28/2007
• Status: Active Grant

• Current Assignee: Olympus Corporation
• Original Assignee: Olympus Imaging Corporation (Olympus Corporation)
• Inventors: Okamura, Takashi, Kawai, Sumio
• Granted Patent: US 7,973,822 B2
• Time in Patent Office: Days
• US Class Current: 348/208.110
• 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
• CPC Class Codes: G03B 2205/0038 by displacing the image plane with respect to the optical axis in case of an electronic image sensor H04N23/68
• CPC Class Codes: G03B 2205/0061 using piezoelectric actuators
• CPC Class Codes: G03B 5/00 Adjustment of optical system relative to image or object surface other than for focusing
• CPC Class Codes: H02N 2/0055 Supports for driving or driven bodies; Means for pressing driving body against driven body
• CPC Class Codes: H02N 2/026 by pressing one or more vibrators against the driven body
• CPC Class Codes: H02N 2/028 along multiple or arbitrary translation directions, e.g. XYZ stages
• CPC Class Codes: H04N 23/55 Optical parts specially adapted for electronic image sensors; Mounting thereof
• CPC Class Codes: H04N 23/68 for stable pick-up of the scene, e.g. compensating for camera body vibrations
• CPC Class Codes: H04N 23/687 by shifting the lens or sensor position
• CPC Class Codes: H10N 30/2023 having polygonal or rectangular shape

Abstract

A drive device includes an actuator, a fixed member, a movable member, rotating members, and a guide member. The actuator is arranged on the fixed member, and includes a piezoelectric element and at least two drivers on the piezoelectric element in parallel with the central axis of the piezoelectric element. The movable member moves by the drivers on the fixed member. The rotating members are located between the fixed member and the movable member to support the movable member. The guide member is arranged on at least one of the fixed member and the movable member, and guides movement of the rotating members in a direction parallel to the central axis of the piezoelectric element. The drivers are located between the rotating members in the direction parallel to the central axis of the piezoelectric element.

Claims

1. A drive device comprising:

an actuator that includes a piezoelectric element having as a whole an elongated shape and at least two drivers that are arranged on the piezoelectric element along an axis parallel to a central axis of the piezoelectric element;

a fixed member on which the actuator is arranged;

a movable member that moves by the drivers on the fixed member;

two rotating members that are located between the fixed member and the movable member to support the movable member that moves on the fixed member; and

a guide member that is arranged on at least one of the fixed member and the movable member, and guides movement of the rotating members in a direction parallel to the central axis of the piezoelectric element, wherein

a positional relation between the drivers and the rotating members is defined such that the drivers are located between the rotating members in the direction parallel to the central axis of the piezoelectric element even when the movable member moves to a maximum extent on the fixed member.

2. The drive device according to claim 1, wherein the rotating members are arranged near edges of the movable member, respectively, and separate from each other.

3. An image stabilizer for correcting a position on a surface of the imaging device where light rays reflected from an object are focused, the image stabilizer comprising:

a first actuator that includes a piezoelectric element having as a whole an elongated shape and at least two first drivers that are arranged on the piezoelectric element along an axis parallel to a central axis of the piezoelectric element, the first actuator being arranged in parallel with a direction of a first side of the imaging device;

a fixed member that includes the first actuator;

a second actuator that includes a piezoelectric element having as a whole an elongated shape and at least two second drivers that are arranged on the piezoelectric element along an axis parallel to a central axis of the piezoelectric element, the second actuator being arranged in parallel with a direction of a second side of the imaging device perpendicular to the first side;

a first movable member that includes the second actuator, and moves, when driven by the first actuator, in the direction of the first side on the fixed member;

a second movable member that is mounted with the imaging device, and moves, when driven by the second actuator, in the direction of the second side on the first movable member;

two first rotating members that are located between the fixed member and the first movable member to support the first movable member that moves on the fixed member; and

two second rotating members that are located between the first movable member and the second movable member to support the second movable member that moves on the first movable member, wherein

the first drivers are located between the first rotating members during operation to move the first movable member, and

the second drivers are located between the second rotating members during operation to move the second movable member.

4. A drive device comprising:

a vibrator that, when applied with a predetermined frequency voltage, causes elliptical vibration having a different phase in each of two driving members;

a fixed member that includes a holding member for holding the vibrator;

a pressing mechanism that presses the driving members of the vibrator arranged on the fixed member; and

a movable member that is driven by the elliptical vibration of the vibrator, moving direction of which is regulated by a guide member of the fixed member, the driving members being in pressure contact with the movable member, wherein

the guide member includes

two first rotating members that are arranged separate from each other;

a first groove that is provided on the fixed member; and

a second groove that is provided on the movable member such that the first rotating members are fitted in between the first groove and the second groove, and

a spacing between the first rotating members is larger than a spacing between the driving members.

5. The drive device according to claim 4 further comprising a second rotating member between the fixed member and the movable member in a position separate from the guide member in a direction other than the moving direction of the movable member.

6. The drive device according to claim 5 further comprising a biasing member that is engaged between the fixed member and the movable member, wherein

the second rotating member is held between the fixed member and the movable member by a biasing force of the biasing member, and

the biasing force of the biasing member is set to be smaller than a biasing force of the pressing mechanism.

7. A drive device comprising:

a vibrator that, when applied with a predetermined frequency voltage, causes a combination of longitudinal vibration and bending vibration as elliptical vibration having a different phase in each of two driving members;

a fixed member that includes a holding member for holding the vibrator;

a pressing mechanism that presses the driving members of the vibrator arranged on the fixed member; and

a movable member that is driven by the elliptical vibration of the vibrator, moving direction of which is regulated by a guide member of the fixed member, the driving members being in pressure contact with the movable member, wherein

the guide member includes

two first rotating members that are arranged separate from each other;

a first groove that is provided on the fixed member; and

a second groove that is provided on the movable member such that the first rotating members are fitted in between the first groove and the second groove, and

the first rotating members are spaced apart greater than a distance between loops of the bending vibration.

8. The drive device according to claim 7 further comprising a second rotating member between the fixed member and the movable member in a position separate from the guide member in a direction other than the moving direction of the movable member, wherein

the first rotating members and the second rotating member are balls.

9. The drive device according to claim 8 further comprising a biasing member that is engaged between the fixed member and the movable member, wherein

the second rotating member is held between the fixed member and the movable member by a biasing force of the biasing member, and

the biasing force of the biasing member is set to be smaller than a biasing force of the pressing mechanism.