Electromagnetic actuator, manufacturing method, and optical scanner using the electromagnetic actuator

• US 6,943,928 B1
• Filed: 09/01/2000
• Issued: 09/13/2005
• Est. Priority Date: 09/03/1999
• Status: Expired due to Fees

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Hirose, Futoshi, Yasuda, Susumu
• Primary Examiner(s): Cherry, Euncha P.
• Application Number:
  US09/654,394
• Time in Patent Office: 1,838 Days
• Field of Search: 359/224, 359/225, 359/198, 359/199, 359/877, 310/12, 310/14
• US Class Current: 359/224.1
• CPC Class Codes: H01F 7/081 Magnetic constructions
• CPC Class Codes: H01F 7/1607 Armatures entering the winding
• CPC Class Codes: H02K 26/00 Machines adapted to function as torque motors, i.e. to exert a torque when stalled
• CPC Class Codes: H02K 33/04 wherein the frequency of operation is determined by the frequency of uninterrupted AC energisation
• CPC Class Codes: H02K 41/035 DC motors; Unipolar motors
• CPC Class Codes: H02K 99/20 Motors
• CPC Class Codes: Y10T 29/49002 Electrical device making
• CPC Class Codes: Y10T 29/49009 Dynamoelectric machine
• CPC Class Codes: Y10T 29/4902 Electromagnet, transformer or inductor
• CPC Class Codes: Y10T 29/49071 by winding or coiling
• CPC Class Codes: Y10T 29/49073 by assembling coil and core

Abstract

An electromagnetic actuator comprises a core with a coil wound around a stator magnetically coupled to each end of the cored a movable element that can be displaced relative to the stator, and a supporting means for supporting the movable element. The stator and the movable element each have a projection and a depression parallel to the displacement direction of the movable element and are placed in such a way that the projection and depression of the stator engage with the projection and depression of the movable element.

Claims

1. An electromagnetic actuator comprising:

a core with a coil wound around said core;

two stators magnetically coupled to each end of said core;

a movable element opposed to said stators with two air gaps; and

supporting means for supporting said movable element to be displacable relative to said two stators,

wherein said stators and said movable element are made of the same material, and

wherein said two stators and said movable element have a projection and a depression in said two air gaps in such a way that the projection and depression of said stators engage with the projection and depression of said movable element, side surfaces of the projection and depression being parallel to the displacement direction of the movable element and partially overlapping even if there is no electromagnetic force.

2. The electromagnetic actuator according to claim 1, wherein said supporting means said stators are fixed onto a substrate.

3. An optical scanner, comprising:

a movable mirror; and

the electromagnetic actuator according to claim 2 mechanically connected with said movable mirror.

4. The electromagnetic actuator according to claim 1, wherein said supporting means is a parallel hinge spring made up of a plurality of flat springs combined in parallel, and the projections and depressions of said stators and the projections and depressions of said movable element are formed like comb-teeth parallel to the direction of movement of said parallel hinge spring.

5. The electromagnetic actuator according to claim 1, wherein said supporting means is a concentric hinge spring combining a plurality of flat springs in a concentric radial form, and the projections and depressions of said stators and the projections and depressions of said movable element are formed in a concentric form around the center of rotation of said concentric hinge spring.

6. An optical scanner, comprising:

a movable mirror; and

the electromagnetic actuator according to claim 1 mechanically connected with said movable mirror.

7. An optical scanner, comprising:

a movable mirror; and

the electromagnetic actuator according to claim 1 mechanically connected with said movable mirror.

8. An optical scanner, comprising:

a movable mirror; and

the electromagnetic actuator according to claim 4 mechanically connected with said movable mirror.

9. An optical scanner, comprising:

a movable mirror; and

the electromagnetic actuator according to claim 5 mechanically connected with said movable mirror.