Anti-shake apparatus

• US 20050168584A1
• Filed: 01/28/2005
• Published: 08/04/2005
• Est. Priority Date: 01/30/2004
• Status: Active Grant

• Current Assignee: PENTAX RICOH IMAGING COMPANY, LTD.
• Original Assignee: Pentax Corporation (Hoya Corporation)
• Inventors: Uenaka, Yukio
• Granted Patent: US 7,352,389 B2
• Time in Patent Office: Days
• US Class Current: 348/208.990
• CPC Class Codes: G03B 2205/0015 by displacing one or more optical elements normal to the optical axis
• CPC Class Codes: G03B 2205/0069 using electromagnetic actuators, e.g. voice coils
• CPC Class Codes: G03B 2217/005 Blur detection
• CPC Class Codes: G03B 5/00 Adjustment of optical system relative to image or object surface other than for focusing
• CPC Class Codes: H04N 23/60 Control of cameras or camera modules
• 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

Abstract

An anti-shake-apparatus of a photographing-apparatus comprises a movable-unit and a fixed-unit. The movable-unit has an imaging-device, a first coil-unit having a first driving-coil and a first position-detecting-coil, and a second coil-unit having a second driving-coil and a second position-detecting-coil. The movable-unit is movable in a first-direction and a second-direction. The fixed-unit has a first permanent-magnet and a second permanent-magnet. The first-direction is perpendicular to an optical-axis of the photographing-apparatus. The second-direction is perpendicular to the optical-axis and the first-direction. The first driving-coil and the first permanent-magnet are used for moving the movable-unit in the first-direction. The second driving-coil and the second permanent-magnet are used for moving the movable-unit in the second-direction. The first position-detecting-coil and the first permanent-magnet are used for detecting a first-location in the first-direction of the movable-unit. The second position-detecting-coil and the second permanent-magnet are used for detecting a second-location in the second-direction of the movable-unit.

Claims

1. An anti-shake apparatus of a photographing apparatus, comprising:

a movable unit that has one of an imaging device and a hand-shake correcting lens, and has a first coil unit having a first driving coil and a first position-detecting coil, and has a second coil unit having a second driving coil and a second position-detecting coil, and is movable in a first direction and a second direction; and

a fixed unit that has a first permanent magnet and a second permanent magnet;

said first direction being perpendicular to an optical axis of a camera lens of said photographing apparatus;

said second direction being perpendicular to said optical axis and said first direction;

said first driving coil and said first permanent magnet being used for moving said movable unit in said first direction;

said second driving coil and said second permanent magnet being used for moving said movable unit in said second direction;

said first position-detecting coil and said first permanent magnet being used for detecting a first location in said first direction of said movable unit; and

said second position-detecting coil and said second permanent magnet being used for detecting a second location in said second direction of said movable unit.

2. The anti-shake apparatus according to claim 1, wherein a first electromotive force, caused by electromagnetic induction, occurs on the basis of a first movement of said first position-detecting coil being included in said movable unit and of a first magnetic-field of said first permanent magnet;

detecting said first location is performed by using a first detected-velocity signal as a velocity of said first movement in said first direction corresponding to said first electromotive force, and a time length of said first movement;

a second electromotive force, caused by electro-magnetic induction, occurs on the basis of a second movement of said second position-detecting coil being included in said movable unit and of a second magnetic-field of said second permanent magnet; and

detecting said second location is performed by using a second detected-velocity signal as a velocity of said second movement in said second direction corresponding to said second electromotive force, and a time length of said second movement.

3. The anti-shake apparatus according to claim 2, wherein the size and the direction of said first electromotive force caused by the electro-magnetic induction, is determined by the size of the force and the direction of said first movement, and by the size and the direction of said first magnetic-field;

and

the size and the direction of said second electromotive force caused by the electro-magnetic induction, is determined by the size of the force and the direction of said second movement, and by the size and the direction of said second magnetic-field.

4. The anti-shake apparatus according to claim 1, wherein said first coil unit is wound, such that its circumference shape, viewed from a third direction which is parallel to said optical axis, is a rectangle and faces said first permanent magnet;

an external structure of said rectangle of said first coil unit, forms lines which are parallel to one of said first direction and said second direction;

said second coil unit is wound, such that its circumference shape, viewed from said third direction, is a rectangle and faces said second permanent magnet;

an external structure of said rectangle of said second coil unit, forms lines which are parallel to one of said first direction and said second direction;

said first permanent magnet is attached to said fixed unit under the condition where the N pole and S pole are arranged in said first direction; and

said second permanent magnet is attached to said fixed unit under the condition where the N pole and S pole are arranged in said second direction.

5. The anti-shake apparatus according to claim 4, wherein said first driving coil forms a seat and spiral shape coil pattern;

said second driving coil forms a seat and spiral shape coil pattern;

said first position-detecting coil forms a seat and spiral shape coil pattern; and

said second position-detecting coil forms a seat and spiral shape coil pattern.

6. The anti-shake apparatus according to claim 5, wherein said seat and spiral shape coil pattern of said first driving coil and said seat and spiral shape coil pattern of said first position-detecting coil are layered in said third direction;

and

said seat and spiral shape coil pattern of said second driving coil and said seat and spiral shape coil pattern of said position-detecting coil are layered in said third direction.

7. The anti-shake apparatus according to claim 1, wherein said movable unit is located at the center of its movable range, in both said first and second directions, when a center area of one of said imaging device and said hand-shake correcting lens which is included in said movable unit, is located on said optical axis.