Image stabilizing apparatus

• US 5,873,004 A
• Filed: 03/19/1997
• Issued: 02/16/1999
• Est. Priority Date: 09/06/1991
• Status: Expired due to Fees

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Shiomi, Yasuhiko
• Primary Examiner(s): ADAMS JR, RUSSELL E
• Application Number:
  US08/820,030
• Time in Patent Office: 699 Days
• Field of Search: 396/52, 396/55, 348/208
• US Class Current: 396/52
• CPC Class Codes: G03B 2205/0007 Movement of one or more optical elements for control of motion blur imaging systems in general using optical elements for stabilisation of the position of the image G02B27/64
• 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 23/68 for stable pick-up of the scene, e.g. compensating for camera body vibrations
• CPC Class Codes: H04N 23/6812 based on additional sensors, e.g. acceleration sensors
• CPC Class Codes: H04N 23/686 with a variable apex prism

Abstract

An image stabilizing apparatus is provided with a plurality of gain setting means arranged in a feedback loop system, a gain switching means for, when an oscillation of the feedback loop system is detected based on an output from a deviation amount detection means, switching gains in the gain setting means, a plurality of phase compensation means arranged in the feedback loop system, and a phase compensation switching means for, when an oscillation of the feedback loop system is detected based on an output from the deviation amount detection means, switching the phase compensation means. The oscillation is suppressed by switching the gains in the gain setting means, switching the phase compensation means, or simultaneously switching them.

Claims

1. An image stabilizing apparatus comprising:

vibration detection means for detecting a vibration;

image stabilizing means for performing image stabilization according to an output from said vibration detection means, said image stabilizing means performing image stabilization by deflecting a light beam by moving an optical member arranged in an optical path;

deviation detection means for detecting a deviation of said optical member by said image stabilizing means;

control means for performing feedback control, so that the output from said vibration detection means and an output from said deviation detection means have a predetermined relationship therebetween;

gain setting means for setting a gain of at least one of the output from said vibration detection means and the output from said deviation detection means; and

gain switching means for, when the output from said vibration detection means and the output from said deviation detection means do not have said predetermined relationship therebetween, switching the gain set by said gain setting means.

2. An image stabilizing apparatus comprising:

vibration detection means for detecting a vibration;

image stabilizing means for performing image stabilization according to an output from said vibration detection means, said image stabilizing means performing image stabilization by deflecting a light beam by moving an optical member arranged in an optical path;

deviation detection means for detecting a deviation of said optical member by said image stabilizing means;

control means for performing feedback control, so that the output from said vibration detection means and an output from said deviation detection means have a predetermined relationship therebetween;

phase compensation means for performing phase compensation of at least one of the output from said vibration detection means and the output from said deviation detection means; and

phase compensation switching means for, when the output from said vibration detection means and the output from said deviation detection means do not have said predetermined relationship therebetween, switching said phase compensation means.

3. An image stabilizing apparatus comprising:

vibration detection means for detecting a vibration;

image stabilizing means for performing image stabilization according to an output from said vibration detection means, said image stabilizing means performing image stabilization by deflecting a light beam by moving an optical member arranged in an optical path;

deviation detection means for detecting a deviation of said optical member by said image stabilizing means;

control means for performing feedback control, so that the output from said vibration detection means and an output from said deviation detection means have a predetermined relationship therebetween;

gain setting means for setting a gain of at least one of the output from said vibration detection means and the output from said deviation detection means;

phase compensation means for performing phase compensation of at least one of the output from said vibration detection means and the output from said deviation detection means; and

switching means for, when the output from said vibration detection means and the output from said deviation detection means do not have said predetermined relationship therebetween, switching at least one of said gain setting means and said phase compensation means.

4. A device adapted for use with an image blur prevention apparatus having an image blur prevention portion for preventing image blur, said device comprising:

a feedback loop for controlling an image blur prevention operation of the image blur prevention portion in response to an output of an image blur detection portion for detecting image blur and an output of a status detection portion for detecting a status of the image blur prevention portion; and

a detection portion that detects an inappropriate status of said feedback loop, the inappropriate status being a status which may prevent a predetermined operation of said image blur prevention portion, said detection portion detecting that the inappropriate status exists when a signal which is unrelated to the output of the image blur detection portion and is also unrelated to the output of the status detection portion is included in a signal within the feedback loop.

5. A device according to claim 4, further comprising removing means for removing the inappropriate status in accordance with a detection by said detection portion.

6. A device according to claim 4, wherein said detection portion comprises means for detecting that the signal within the feedback loop includes a signal having a higher frequency component than a predetermined frequency.

7. A device according to claim 6, wherein said detection portion comprises means for detecting that an amplitude of the signal having the higher frequency component than the predetermined frequency is greater than or equal to a predetermined amplitude.

8. A device according to claim 5, wherein said removing means comprises means for varying a loop gain of the feedback loop.

9. A device according to claim 8, wherein said removing means comprises means for reducing the loop gain of the feedback loop.

10. A device according to claim 5, wherein said removing means comprises means for varying a phase compensation characteristic of the feedback loop.

11. A device according to claim 4, wherein the image blur prevention portion comprises a movable member, and the status detection portion comprises means for detecting a movement status of the movable member.

12. A device according to claim 11, wherein the image blur prevention portion comprises an optical member moving in an optical path, and the status detection portion comprises displacement status detection means for detecting a displacement status of the optical member.

13. A device according to claim 12, wherein the control portion comprises means for controlling a displacement of the image blur prevention portion based on a difference between the output of the image blur detection portion and an output of the displacement status detection portion.

14. A device according to claim 11, wherein said device further comprises the control portion.

15. A device according to claim 4, wherein the image blur detection portion comprises means for detecting a fluctuation of said device.

16. A device according to claim 4, wherein the image blur prevention portion comprises means for deflecting a light beam by moving into an optical path.

17. An image blur prevention apparatus comprising:

image blur prevention means for preventing image blur;

a feedback loop for controlling an image blur prevention operation of the image blur prevention means in response to an output of an image blur detection portion for detecting image blur and an output of a status detection portion for detecting a status of the image blur prevention portion; and

detection means for detecting an inappropriate status of said feedback loop, the inappropriate status being a status which may prevent a predetermined operation of said image blur prevention portion, said detection means detecting that the inappropriate status exists when a signal which is unrelated to the output of the image blur detection portion and is also unrelated to the output of the status detection portion is included in a signal within the feedback loop.

18. An apparatus according to claim 17, further comprising removing means for removing the inappropriate status in accordance with a detection by said detection means.

19. An optical apparatus, comprising:

a feedback loop for controlling an image blur prevention operation of an image blur prevention portion in response to an output of an image blur detection portion for detecting image blur and an output of a status detection portion for detecting a status of the image blur prevention portion; and

a detection portion that detects an inappropriate status of said feedback loop, the inappropriate status being a status which may prevent a predetermined operation of said image blur prevention portion, said detection portion detecting that the inappropriate status exists when a signal which is unrelated to the output of the image blur detection portion and is also unrelated to the output of the status detection portion is included in a signal within the feedback loop.

20. An equipment according to claim 19, further comprising removing means for removing the inappropriate status in accordance with a detection by said detection portion.

21. A device adapted for use with an image blur prevention apparatus having an image blur prevention portion for preventing image blur, said device comprising:

a feedback loop for controlling an image blur prevention operation of the image blur prevention portion; and

a determination portion for determining whether the feedback loop is in an oscillating condition.

22. An apparatus according to claim 21, wherein the feedback loop comprises means for controlling the operation of the image blur prevention portion in accordance with an output of an image blur detection portion for detecting an image blur status.

23. An apparatus according to claim 21, wherein the feedback loop comprises means for controlling the operation of the image blur prevention portion in accordance with an output of a status detection portion for detecting a status of the image blur prevention portion.

24. An apparatus according to claim 23, wherein the image blur prevention portion comprises a movable member, and the status detection portion comprises means for detecting a movement status of the movable member.

25. An apparatus according to claim 23, wherein the feedback loop comprises means for controlling the operation of the image blur prevention portion in accordance with the output of the status detection portion and an output of an image blur detection portion for detecting an image blur status.

26. An apparatus according to claim 21, wherein said determination portion comprises means for determining that the oscillating condition is occurring in accordance with a frequency characteristic of a signal in the feedback loop.

27. An apparatus according to claim 26, wherein said detection portion comprises means for detecting that the signal within the feedback loop includes a signal having a higher frequency component than a predetermined frequency.

28. An apparatus according to claim 21, wherein said determination portion comprises means for determining that the oscillating condition is occurring in accordance with an amplitude of a signal in the feedback loop.

29. An apparatus according to claim 21, further comprising eliminating means for eliminating the oscillating condition if the determination portion determines that the oscillating condition is occurring in the feedback loop.

30. An apparatus according to claim 29, wherein said eliminating means comprises means for eliminating the oscillating condition by changing a loop gain of the feedback loop.

31. An apparatus according to claim 29, wherein said eliminating means comprises means for eliminating the oscillating condition by changing a phase compensation characteristic of the feedback loop.

32. An image blur prevention apparatus comprising:

image blur prevention means for preventing image blur;

a feedback loop for controlling an image blur prevention operation of the image blur prevention means in response to an output of an image blur detection portion for detecting image blur; and

a determination portion for determining whether the feedback loop is in an oscillating condition.

33. An optical apparatus having a feedback loop for controlling an image blur prevention operation of an image blur prevention portion in response to output of an image blur detection portion, said optical apparatus comprising:

a determination portion for determining whether the feedback loop is in an oscillating condition.

34. A device adapted for use with an image blur prevention apparatus having an image blur prevention portion for preventing image blur, said device comprising:

a feedback loop for controlling an image blur prevention operation of the image blur prevention portion in accordance with an output of a signal output means for outputting a predetermined signal;

determination means for determining a status of the feedback loop; and

changing means for changing at least one of a gain of the signal of the signal output means and a phase compensation characteristic of the feedback loop in accordance with a determination by said determination means.

35. A device according to claim 34, wherein the feedback loop comprises means for controlling the operation of the image blur prevention portion in accordance with an output of an image blur detection portion for detecting an image blur status, and said changing means comprises means for changing at least one of a gain of the output of the image blur detection portion and the phase compensation characteristic.

36. A device according to claim 34, wherein the feedback loop controls the operation of the image blur prevention portion in accordance with an output of a status detection portion for detecting a status of the image blur prevention portion, and said changing means comprises means for changing at least one of a gain of the output of the status detection portion and the phase compensation characteristic.

37. A device according to claim 34, wherein said determination means comprises means for determining whether an oscillating condition is occurring in the feedback loop.

38. An image blur prevention apparatus adapted for use with an image blur prevention apparatus having an image blur prevention portion for preventing image blur and a feedback loop for controlling an image blur and a feedback loop for controlling an image blur prevention operation of the image blur prevention portion in accordance with an output of signal output means for outputting a predetermined signal, the device comprising:

determination means for determining a status of the feedback loop; and

changing means for changing at least one of a gain of the signal of the signal output means and a phase compensation characteristic of the feedback loop in accordance with a determination by said determination means.

39. An optical apparatus adapted for use with an image blur prevention apparatus having an image blur prevention portion for preventing image blur and a feedback loop for controlling an image blur prevention operation of the image blur prevention portion in accordance with an output of signal output means for outputting a predetermined signal, the optical apparatus comprising:

determination means for determining a status of the feedback loop; and

changing means for changing at least one of a gain of the signal of the signal output means and a phase compensation characteristic of the feedback loop in accordance with a determination by said determination means.