Image pickup apparatus with moving image and still image focus control based on changing threshold value

• US 6,727,949 B1
• Filed: 12/10/1996
• Issued: 04/27/2004
• Est. Priority Date: 09/29/1993
• Status: Expired due to Fees

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Mizoguchi, Yoshiyuki, Fujii, Takashi, Saruwatari, Hiroshi, Murakami, Taro, Yamaguchi, Toshinobu
• Primary Examiner(s): HO, TUAN V
• Application Number:
  US08/762,929
• Time in Patent Office: 2,695 Days
• Field of Search: H04/N.5232, 348/207, 348/220, 348/221, 348/345, 348/349, 348/362, 348/363, 348/364, 348/221.1, 348/220.1, 348/207.99
• US Class Current: 348/349
• CPC Class Codes: H04N 23/667 Camera operation mode switching, e.g. between still and video, sport and normal or high- and low-resolution modes
• CPC Class Codes: H04N 23/673 based on contrast or high frequency components of image signals, e.g. hill climbing method

Abstract

In an image pickup apparatus which permits switching between a moving-image shooting mode and a still image shooting mode and is provided with an automatic focusing device for focus adjustment by detecting a high frequency component of a video signal to use it as a focus evaluating signal, the focusing action of the automatic focusing device is arranged to be restarted when the moving-image shooting mode is switched to the still-image shooting mode.

Claims

1. An image pickup apparatus capable of setting a moving-image shooting mode and a still-image shooting mode, comprising:

a) switching means for switching between the moving-image shooting mode and the still-image shooting mode;

b) focusing means for automatically adjusting a focus state in the moving-image shooting mode and still-image shooting mode; and

c) control means for restarting said focusing means to execute a focus adjusting operation in response to a switching operation between the moving-image shooting mode and the still-image shooting mode by said switching means,

wherein said control means is arranged to vary a characteristic of said focusing means correspondingly with the moving-image shooting mode or the still-image shooting mode, and

wherein the characteristic of said focusing means to be varied by said control means is a threshold value which is set to be used for restarting said focusing means.

2. An image pickup apparatus capable of setting a moving-image shooting mode and a still-image shooting mode, comprising:

a) switching means for switching between the moving-image shooting mode and the still-image shooting mode;

b) focusing means for automatically adjusting focus state in the moving-image shooting mode and still-image shooting mode; and

c) control means for restarting said focusing means to execute a focus adjusting operation in response to a switching operation between the moving-image shooting mode and the still-image shooting mode by said switching means,

wherein said control means is arranged to vary a characteristic of said focusing means correspondingly with the moving-image shooting mode or the still-image shooting mode, and

wherein the characteristic of said focusing means to be varied by said control means is a focus adjusting speed and a response characteristic and speed of an exposure control member.

3. A video camera apparatus capable of setting a moving-image shooting mode and a still-image shooting mode, comprising:

a) mode switching means for switching between the moving-image shooting mode and the still-image shooting mode;

b) focus adjusting means for adjusting controlling a focus condition in both of the shooting modes; and

c) control means for restarting said focus adjusting means to execute a focus adjusting operation in response to a switching operation of said mode switching means between the moving-image shooting mode and the still-image shooting mode,

wherein said control means is arranged to vary a characteristic of said focusing means correspondingly with the moving-image shooting mode or the still-image shooting mode, and

wherein the characteristic of said focusing means to be varied by said control means is a threshold value which is set to be used for restarting said focusing means.

4. A video camera apparatus capable of setting a moving-image shooting mode and a still-image shooting mode, comprising:

a) mode switching means for switching between the moving-image shooting mode and the still-image shooting mode;

b) focus adjusting means for adjusting controlling a focus condition in both of the shooting modes; and

c) control means for restarting said focus adjusting means to execute a focus adjusting operation in response to a switching operation of said mode switching means,

wherein said control means is arranged to vary a characteristic of said focusing means correspondingly with the moving image shooting mode or the still-image shooting mode, and

wherein the characteristic of said focusing means to be varied by said control means is a focus adjusting speed and a response characteristic and speed of an exposure control member.

5. An image pickup apparatus comprising:

a focusing device that performs a first focusing operation for a moving-image and a second focusing operation, which is capable of obtaining a sharper image than the first focusing operation by changing a threshold value for restarting focusing control, for a still-image; and

a control device that switches between the first focusing operation and the second focusing operation.

6. An apparatus according to claim 5, further comprising:

an image pickup device that converts an optical image into an image signal,

wherein said focusing device performs the first focusing operation and the second focusing operation with a high frequency component extracted from the image signal.

7. An apparatus according to claim 5, further comprising:

an image pickup device that converts an optical image into an image signal for photography,

wherein said focusing device performs the first focusing operation and the second focusing operation with a high frequency component extracted from the image signal.

8. An apparatus according to claim 5, further comprising:

a image pickup device that converts an optical image into an image signal,

wherein said focusing device performs the first focusing operation and the second focusing operation in a same manner by using a high frequency component extracted from the image signal.

9. An apparatus according to claim 5, further comprising:

a image pickup device that converts an optical image into an image signal for photography,

wherein said focusing device performs the first focusing operation and the second focusing operation in a same manner by using a high frequency component extracted from the image signal.

10. An apparatus according to claim 5, wherein said control device switches from the first focusing operation to the second focusing operation in response to operating an operation member for starting a still-image shooting operation.

11. An apparatus according to claim 5, wherein said control device switches between the first focusing operation and the second focusing operation by switching between a moving-image shooting mode and a still-image shooting mode.

12. An apparatus according to claim 5, wherein said control device switches between the first focusing operation and the second focusing operation by switching between a moving-image shooting mode from a still-image shooting mode and operating an operation member for starting a still-image shooting operation.

13. An image pickup apparatus comprising:

a focusing device that performs a first focusing operation for a moving-image and a second focusing operation, which is capable of obtaining a sharper image than the first focusing operation by changing a threshold value for restarting focusing control, for a still-image; and

a control device that starts the second focusing operation, regardless of a focusing state by the first focusing operation, by switching from a moving-image shooting mode to a still-image shooting mode.

14. An apparatus according to claim 13, wherein said control device starts the first focusing operation, in accordance with a focusing state by the second focusing operation, by switching from the still-image shooting mode to the moving-image shooting mode.

15. An apparatus according to claim 13, further comprising:

a image pickup device that converts an optical image into an image signal,

wherein said focusing device performs the first focusing operation and the second focusing operation with a high frequency component extracted from the image signal.

16. An apparatus according to claim 13, wherein said control device switches from the first focusing operation to the second focusing operation in response to operating an operation member for starting a still-image shooting operation.

17. An apparatus according to claim 13, wherein said control device switches between the first focusing operation and the second focusing operation by switching between a moving-image shooting mode and a still-image shooting mode.

18. An apparatus according to claim 13, wherein said control device switches between the first focusing operation and the second focusing operation by switching between a moving-image shooting mode from a still-image shooting mode and operating an operation member for starting a still-image shooting operation.

19. An image pickup apparatus comprising:

a focusing device that performs a first focusing operation for a moving-image and a second focusing operation, which is capable of obtaining a sharper image than the first focusing operation by changing a threshold value for restarting focusing control, for a still-image; and

a control device that starts the first focusing operation, in accordance with a focusing state by the second focusing operation, by switching from a still-image shooting mode to a moving-image shooting mode.

20. An apparatus according to claim 19, further comprising:

a image pickup device that converts an optical image into an image signal,

wherein said focusing device performs the first focusing operation and the second focusing operation with a high frequency component extracted from the image signal.

21. An apparatus according to claim 19, wherein said control device switches from the first focusing operation to the second focusing operation in response to operating an operation member for starting a still-image shooting operation.

22. An apparatus according to claim 19, wherein said control device switches between the first focusing operation and the second focusing operation by switching between a moving-image shooting mode and a still-image shooting mode.

23. An apparatus according to claim 19, wherein said control device switches between the first focusing operation and the second focusing operation by switching between a moving-image shooting mode from a still-image shooting mode and operating an operation member for starting a still-image shooting operation.

24. An image pickup apparatus comprising:

a switching device that switches between a moving-image pickup mode and a still-image pickup mode; and

a control device that performs an operation for focusing obtaining a higher in-focus degree in said still-image pickup mode than in said moving-image pickup mode by changing a threshold value for restarting focusing control, in response to being changed from said moving-image pickup mode to said still-image pickup mode by said switching device.

25. An image pickup apparatus according to claim 24, further comprising:

an image pickup device that converts an optical image into an image signal,

wherein said control device performs the operation for focusing in said moving-image pickup mode and still-image pickup mode with a high frequency component extracted from the image signal.

26. An image pickup apparatus according to claim 24, further comprising:

an image pickup device that converts an optical image into an image signal for photography,

wherein said control device performs the operation for focusing in said moving-image pickup mode and still-image pickup mode with a high frequency component extracted from the image signal.

27. An image pickup apparatus according to claim 24, further comprising:

an image pickup device that converts an optical image into an image signal,

wherein said control device performs the operation for focusing in said moving-image pickup mode and still-image pickup mode in a same manner by using a high frequency component extracted from the image signal.

28. An image pickup apparatus according to claim 24, further comprising:

an image pickup device that converts an optical image into an image signal for photography,

wherein said control device performs the operation for focusing in said moving-image pickup mode and still-image pickup mode in a same manner by using a high frequency component extracted from the image signal.

29. An image pickup apparatus according to claim 24, wherein said control device starts the operation for focusing in response to being changed from said moving-image pickup mode to said still-image pickup mode by said changing device, regardless of a focusing state in said moving-image pickup mode.

30. An image pickup apparatus according to claim 24, wherein said control device restarts the operation for focusing in response to being changed from said moving-image pickup mode to said still-image pickup mode by said changing device.

31. An image pickup apparatus according to claim 24, wherein said control device changes an evaluation value for focusing for said moving-image pickup mode to an evaluation value for focusing for said still-image pickup mode in response to being changed from said moving-image pickup mode to said still-image pickup mode by said changing device.

32. An image pickup apparatus comprising:

a switching device that switches between a moving-image pickup mode and a still-image pickup mode; and

a control device that changes a threshold value for restarting focusing control for said moving-image pickup mode to an evaluation value for focusing for said still-image pickup mode in response to being changed from said moving-image pickup mode to said still-image pickup mode by said changing device.

33. An image pickup apparatus according to claim 32, further comprising:

an image pickup device that converts an optical image into an image signal,

wherein said control device performs the operation for focusing in said moving-image pickup and still-image pickup mode with a high frequency component extracted from the image signal.

34. An image pickup apparatus according to claim 32, further comprising:

an image pickup device that converts an optical image into an image signal for photography,

wherein said control device performs the operation for focusing in said moving-image pickup mode and still-image pickup mode with a high frequency component extracted from the image signal.

35. An image pickup apparatus according to claim 32, further comprising:

image pickup device that converts an optical image into an image signal,

wherein said control device performs the operation for focusing in said moving-image pickup mode and still-image pickup mode in a same manner by using a high frequency component extracted from the image signal.

36. An image pickup apparatus according to claim 32, further comprising:

an image pickup device that converts an optical image into an image signal for photography,

wherein said control device performs the operation for focusing in said moving-image pickup mode and still-image pickup mode in a same manner by using a high frequency component extracted from the image signal.

37. An image pickup apparatus according to claim 32, wherein said control device starts the operation for focusing in response to being changed from said moving-image pickup mode to said still-image pickup mode by said changing device, regardless of a focusing state in said moving-image pickup mode.

38. An image pickup apparatus according to claim 32, wherein said control device restarts the operation for focusing in response to being changed from said moving-image pickup mode to said still-image pickup mode by said changing device.