Camera having automatic focusing device

• US 6,308,015 B1
• Filed: 06/14/2000
• Issued: 10/23/2001
• Est. Priority Date: 06/18/1999
• Status: Expired due to Fees

• Current Assignee: Olympus Optical Corporation Limited (Olympus Corporation)
• Original Assignee: Olympus Optical Corporation Limited (Olympus Corporation)
• Inventors: Matsumoto, Hisayuki
• Primary Examiner(s): Gray, David M.
• Assistant Examiner(s): BLACKMAN, ROCHELLE ANN J
• Application Number:
  US09/593,897
• Time in Patent Office: 496 Days
• Field of Search: 396/89, 396/95, 396/107, 396/108, 396/109, 396/110, 396/104, 396/106, 396/92, 396/121
• US Class Current: 396/106
• CPC Class Codes: G02B 7/285 including two or more different focus detection devices, e.g. both an active and a passive focus detecting device
• CPC Class Codes: G03B 13/36 Autofocus systems

Abstract

There is provided a camera with an automatic focusing device having hybrid AF unit capable of always performing a reliable automatic focusing operation on a moving object to provide a more preferable photographic result. The camera includes first distance measuring unit 4 having at least a pair of light receiving sensors, for measuring the distance of an object by receiving a beam of light from the object, second distance measuring unit 3 having light projecting unit for projecting a beam of light upon the object and light receiving unit for receiving a beam of light reflected therefrom, for measuring the distance of the object by projecting a beam of light upon the object with the light projecting unit and by receiving a beam of light reflected therefrom with the light receiving unit and distance measuring method selecting unit 2 for selecting either the first distance measuring unit or the second distance measuring unit. The distance measuring method selecting unit is controlled such that it selects the first distance measuring unit when performing an automatic focusing operation which is most suitable for photographing a moving object.

Claims

1. A camera with an automatic focusing device, comprising:

a first distance measuring unit having at least a pair of light receiving elements, for performing a distance measuring calculation by receiving a beam of light from an object;

a second distance measuring unit having a light projecting portion for projecting a beam of light upon an object, for performing a distance measuring calculation by receiving a beam of light which is reflection of the beam of light projected by said light projecting portion; and

a distance measuring method selecting unit for selecting said first distance measuring unit when performing an automatic focusing operation which is most suitable for photographing a moving object.

2. A camera according to claim 1, further comprising:

a photographic mode selecting unit for selecting a desired photographic mode from among a plurality of preset photographic mode,

wherein said plurality of photographic modes include a moving object shooting mode.

3. A camera according to claim 2, wherein said distance measuring method selecting unit selects said first distance measuring unit when said photographic mode selecting unit selects said moving object shooting mode.

4. A camera according to claim 3, wherein said first distance measuring unit performs a moving object predicting calculation process.

5. A camera according to claim 1, further comprising:

a moving object determining unit for determining whether an object is moving or not,

wherein said distance measuring method selecting unit selects said first distance measuring unit when said moving object determining unit determines that an object of interest is in a moving state.

6. A camera according to claim 1, wherein said first distance measuring unit performs a passive distance measuring calculation.

7. A camera according to claim 1, wherein said second distance measuring unit performs an active distance measuring calculation.

8. A camera with an automatic focusing device, comprising:

a first distance measuring unit having at least a pair of light receiving elements, for performing a passive distance measuring calculation by receiving a beam of light from an object;

a second distance measuring unit having a light projecting portion for projecting a beam of light upon an object, for performing an active distance measuring calculation by receiving a beam of light which is reflection of the beam of light projected by said light projecting portion;

a distance measuring method selecting unit for selecting either said first distance measuring unit or said second distance measuring unit; and

photographic mode selecting unit for selecting a desired photographic mode from among a plurality of photographic modes including at least a moving object shooting mode and a full automatic photographic mode,

wherein said distance measuring method selecting unit selects said first distance measuring unit when said photographic mode selecting unit selects the moving object shooting mode.

9. A camera according to claim 8, wherein an amount of deviation between the positions of images formed by said pair of light receiving elements is calculated a plurality of times when said photographic mode selecting unit selects the moving object shooting mode.

10. A camera according to claim 9, wherein a moving object predicting calculation for obtaining a predicted amount of deviation is performed based on the amount of deviation calculated by said plurality of calculations.

11. A camera according to claim 10, wherein a predicted distance of an object is calculated based on said predicted amount of deviation.

12. A camera according to claim 11, wherein a driving amount for a photographic optical system is calculated based on said predicted distance of an object.

13. A camera according to claim 8, wherein said distance measuring method selecting unit selects either said first distance measuring unit or said second distance measuring unit when said photographic mode selecting unit selects the full automatic photographic mode and selects the other distance measuring unit when no result is available from measurement performed by selected distance measuring unit.

14. A camera according to claim 13, wherein an amount of deviation between the positions of images formed by said pair of light receiving elements is calculated a plurality of times when said distance measuring method selecting unit selects said first distance measuring unit.

15. A camera according to claim 14, wherein a moving object predicting calculation for obtaining a predicted amount of deviation is performed based on the amount of deviation calculated by said plurality of calculations.

16. A camera according to claim 15, wherein a predicted distance of an object is calculated based on said predicted amount of deviation.

17. A camera according to claim 16, wherein a driving amount for a photographic optical system is calculated based on said predicted distance of an object.

18. A camera according to claim 13, wherein an amount of deviation between the positions of images formed by said pair of light receiving elements is calculated a plurality of times when said distance measuring method selecting unit selects said second distance measuring unit.

19. A camera according to claim 18, wherein a moving object predicting calculation for obtaining a predicted amount of deviation is performed based on the amount of deviation calculated by said plurality of calculations.

20. A camera according to claim 19, wherein it is determined whether an object of interest is moving or not based on said predicted amount of deviation.

21. A camera according to claim 20, wherein said distance measuring method selecting unit sets a selection flag for selecting said first distance measuring unit at the next selecting operation by said distance measuring method selecting unit when it is determined that said object of interest is moving.

22. A camera according to claim 8, wherein setting in accordance with the environment of an object of interest is automatically made in said full automatic photographic mode.

23. A method for automatically focusing a camera having a first distance measuring unit for performing a passive distance measuring calculation and a second distance measuring unit for performing an active distance measuring calculation, the method comprising:

selecting a desired photographic mode from among a plurality of photographic modes;

selecting said first distance measuring unit as a distance measuring unit to perform a distance measuring calculation when a moving object shooting mode is selected; and

performing a distance measuring calculation including a moving object predicting calculation process if said first distance measuring unit is selected.

24. A method for automatically focusing a camera having a first distance measuring unit for performing a passive distance measuring calculation and a second distance measuring unit for performing an active distance measuring calculation, the method comprising:

selecting a desired photographic mode from among a plurality of photographic modes;

selecting said second distance measuring unit as a distance measuring unit to perform a distance measuring calculation when a full automatic photographic mode is selected;

performing a distance measuring calculation including a moving object predicting calculation process with said second distance measuring unit selected;

determining whether an object is moving or not based on a result of the moving object predicting calculation process; and

setting a selection flag for selecting said first distance measuring unit at a next selection process when an object is determined to be a moving object.