Optical element driving device and imaging device

• US 8,351,771 B2
• Filed: 07/13/2010
• Issued: 01/08/2013
• Est. Priority Date: 08/18/2009
• Status: Expired due to Fees

• Current Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Ito, Daisuke
• Primary Examiner(s): Perkey, W. B.
• Assistant Examiner(s): PHAN, MINH Q
• Application Number:
  US12/834,896
• Publication Number:
  US 20110044672A1
• Time in Patent Office: 910 Days
• Field of Search: 396/55, 348/208.99, 348/208.4, 348/208.7, 348/208.11, 359554-557
• US Class Current: 396/55
• 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: G02B 7/023 permitting adjustment
• CPC Class Codes: G02B 7/08 adapted to co-operate with a remote control mechanism
• CPC Class Codes: G03B 17/00 Details of cameras or camera bodies; Accessories therefor lens hoods or caps G03B11/04

Abstract

An optical element driving device is provided with at least one optical element, a moving member, a fixed member, a first actuator, a first detection element, a second actuator, and a second detection element. The first actuator has a first coil and a first magnet. The first detection element is substantially aligned in a first direction relative to the first coil to detect the position of the moving member in the first direction. The second actuator has a second coil and a second magnet. The second detection element is substantially aligned in the first direction relative to the second coil to detect the position of the moving member in a second direction. The optical element, the first actuator, and the second actuator are substantially aligned in the first direction.

Claims

1. An optical element driving device comprising:

at least one optical element having an optical axis;

a moving member configured to move and support the optical element;

a fixed member movably supporting the moving member in a direction perpendicular to the optical axis;

a first actuator including a first coil coupled to one of the moving member and the fixed member and a first magnet disposed opposite to the first coil and coupled to a different one of the moving member and the fixed member, the first magnet including a first portion having a first magnetic pole, a second portion having a second magnetic pole different from the first magnetic pole and a third portion having the first magnetic pole,

the first, the second and the third portions extending in a first direction with the first and second portions being separated by a first polarization line substantially parallel to a second direction and substantially perpendicular to the first direction, the second and third portions being separated by a second polarization line substantially parallel to the first polarization line, the first actuator being configured to drive the moving member in the first direction;

a first detection element coupled to one of the moving member and the fixed member together with the first coil to detect the position of the moving member in the first direction relative to the fixed member, the first coil being disposed opposite to the first polarization line, and the first detection element being disposed opposite to the second polarization line;

a second actuator including a second coil coupled to one of the moving member and the fixed member and a second magnet disposed opposite to the second coil and coupled to a different one of the moving member and the fixed member, the second actuator being configured to drive the moving member in the second direction substantially perpendicular to the first direction; and

a second detection element coupled to one of the moving member and the fixed member together with the second coil to detect the position of the moving member in the second direction relative to the fixed member,

the first actuator being substantially aligned in the first direction with the optical element when viewed in a third direction parallel to the optical axis,

the first detection element being substantially aligned in the first direction with the first coil when viewed in the third direction, and

the second detection element and the second coil being substantially aligned in the first direction with the first actuator when viewed in the third direction.

2. The optical element driving device according to claim 1, wherein

at least part of the first detection element overlaps the first coil when viewed from the first direction.

3. The optical element driving device according to claim 1, wherein

the first detection element overlaps a line passing through the center of the first coil and the optical axis when viewed from the third direction.

4. The optical element driving device according to claim 1, wherein

the first detection element is on the opposite side of the first coil from the optical element when viewed from the third direction.

5. The optical element driving device according to claim 1, wherein

the first coil is disposed between the optical element and the first detection element when viewed from the third direction.

6. The optical element driving device according to claim 1, wherein

the optical element is disposed between the first actuator and the second actuator when viewed from the third direction.

7. The optical element driving device according to claim 1, further comprising:

a rotating shaft extending in the third direction and coupled to one member selected from among the fixed member and the moving member; and

a guide portion including a rotary guide groove to receive the rotating shaft, the guide portion being joined to a different member selected from among the fixed member and the moving member.

8. The optical element driving device according to claim 7, wherein

the rotating shaft is on the outside of the optical element when viewed from the third direction.

9. The optical element driving device according to claim 8, wherein

the rotating shaft, the optical element, the first actuator and the second actuator are substantially aligned along the first direction.

10. The optical element driving device according to claim 8, wherein

the first actuator is on the same side of the optical element as the rotating shaft and extends along the first direction.

11. The optical element driving device according to claim 8, wherein

the first detection element is arranged closer to the rotating shaft than the first coil.

12. The optical element driving device according to claim 8, wherein

the first detection element is disposed between the rotating shaft and the first coil.

13. The optical element driving device according to claim 12, wherein

the first detection element overlaps a first reference line that links the optical axis and the center of the rotating shaft when viewed in the third direction.

14. The optical element driving device according to claim 8, wherein

the center of the rotating shaft, the center of the first coil, and the center of the first detection element are linearly aligned in the first direction.

15. The optical element driving device according to claim 8, wherein

the second detection element is arranged closer to the rotating shaft than the second coil.

16. The optical element driving device according to claim 1, wherein

the optical axis of the optical element, the center of the first coil, and the center of the first detection element are linearly aligned in the first direction.

17. The optical element driving device according to claim 1, further comprising:

a guide mechanism configured to guide the moving member in a direction perpendicular to the optical axis and including a first guide member and a second guide member fixed to the fixed member, a first sliding portion mounted on the moving member and arranged to matingly receive the first guide member and a second sliding portion mounted on the moving member and arranged to matingly receive the second guide member, the point of contact between the first sliding portion and the first guide member along the second direction is larger than the point of contact between the second sliding portion and the second guide member in the same direction.

18. The optical element driving device according to claim 17, wherein

the first magnet is larger than the second magnet, and at least part of the first sliding portion overlaps the first magnet and at least part of the second sliding portion overlaps the second magnet when viewed from the third direction.

19. The optical element driving device according to claim 18, wherein

the first magnet and the second magnet are coupled to the moving member.

20. An imaging device comprising:

an imaging optical system including a correcting lens configured to form an optical image of a subject;

an imaging element configured to convert an optical image of the subject into an image signal; and

the optical element driving device according to claim 19 to drive one of the correcting lens and the imaging element as the optical element.

21. The imaging device according to claim 20, wherein

the imaging optical system further includes a first optical system having a first optical axis and a second optical axis that intersects the first optical axis and configured and arranged to reflect light that is incident along the first optical axis in a direction parallel to the second optical axis and a second optical system having the correcting lens and configured and arranged to guide light emitted from the first optical system along the second optical axis to the imaging element.

22. The imaging device according to claim 21, wherein

the first direction is perpendicular to a plane that includes the first optical axis and the second optical axis, and the second direction is parallel to the first optical axis, and the third direction is parallel to the second optical axis.

23. The optical element driving device according to claim 1, further comprising:

a rotating shaft extending in the third direction and coupled to one member selected from among the fixed members and the moving member, wherein the first actuator is closer to the rotating shaft than the second actuator.

24. The optical element driving device according to claim 1, further comprising:

a rotating shaft extending in the third direction and coupled to one member selected from among the fixed members and the moving member, wherein

the first detection element is disposed between the first actuator and the rotating shaft.