CAMERA HAVING AN AUTOFOCUSING SYSTEM

• US 20080316325A1
• Filed: 06/09/2008
• Published: 12/25/2008
• Est. Priority Date: 06/19/2007
• Status: Active Grant

• Current Assignee: PENTAX RICOH IMAGING COMPANY, LTD.
• Original Assignee: Hoya Corporation
• Inventors: NAKAHARA, Naoto
• Granted Patent: US 8,169,530 B2
• Time in Patent Office: Days
• US Class Current: 348/222.1
• CPC Class Codes: G06V 40/166 using acquisition arrangements
• CPC Class Codes: H04N 23/61 based on recognised objects
• CPC Class Codes: H04N 23/611 where the recognised objects include parts of the human body
• CPC Class Codes: H04N 23/635 Region indicators; Field of view indicators
• CPC Class Codes: H04N 23/673 based on contrast or high frequency components of image signals, e.g. hill climbing method
• CPC Class Codes: H04N 23/675 comprising setting of focusing regions

Abstract

An autofocus camera having a face recognition function, includes a photographing optical system including a focusing lens group; an image pickup device; an autofocusing system which performs a focus search process, and further performs a focusing operation in which the focusing lens group is moved to an in-focus position that is detected by the focus search process; a switch which activates the autofocusing system; a face recognition device for recognizing a face image based on object images; and a controller which makes the autofocusing system set the focus detection area on a face recognition area at which the face image is recognized and makes the autofocusing system perform the focus search process and the focusing operation on the focus detection area regardless of whether the switch is turned ON when the face recognition device recognizes the face image.

Claims

1. An autofocus camera having a face recognition function, comprising:

a photographing optical system including a focusing lens group movable along an optical axis;

an image pickup device;

an autofocusing system which performs a focus search process in which said image pickup device is activated to capture an object image at each of a plurality of different positions of said focusing lens group in said optical axis direction while said focusing lens group is moved along said optical axis to detect a position of said focusing lens group in said optical axis direction as an in-focus position based on said object images obtained at said plurality of different positions of said focusing lens group in at least one focus detection area, and further performs a focusing operation in which said focusing lens group is moved to said in-focus position that is detected by said focus search process;

a switch which activates said autofocusing system upon being turned ON;

a face recognition device for recognizing a face image based on said object images; and

a controller which makes said autofocusing system set said focus detection area on a face recognition area at which said face image is recognized by said face recognition device and makes said autofocusing system perform said focus search process and said focusing operation on said focus detection area regardless of whether said switch is turned ON when said face recognition device recognizes said face image.

2. The autofocus camera according to claim 1, wherein said controller makes said autofocusing system set said focus detection area on said face recognition area and makes said autofocusing system perform said focus search process and said focusing operation on said focus detection area regardless of whether said switch is turned ON one of upon a lapse of a predetermined period of time after said face recognition device recognizes said face image and upon said face recognition device recognizing said face image consecutively a predetermined number of times.

3. The autofocus camera according to claim 1, further comprising a portrait mode as one of selectable exposure modes of said autofocus camera,

wherein, after said portrait mode is selected, said controller makes said autofocusing system set said focus detection area on said face recognition area and makes said autofocusing system perform said focus search process and said focusing operation on said focus detection area regardless of whether said switch is turned ON one of upon a lapse of a predetermined period of time after said face recognition device recognizes said face image and upon said face recognition device recognizing said face image consecutively a predetermined number of times.

4. The autofocus camera according to claim 1, wherein said controller limits a range of movement of said focusing lens group in said focus search process from one to the other of a near extremity and a far extremity to a narrow range including a current position of said focusing lens group upon said switch being turned ON after said autofocusing system performs said focus search process and said focusing operation following recognition of said face image by said face recognition device.

5. The autofocus camera according to claim 4, wherein said controller does not limit said range of movement of said focusing lens group in said focus search process to said narrow range when said autofocusing system performs said focus search process and said focusing operation following said recognition of said face image by said face recognition device.

6. The autofocus camera according to claim 4, wherein, in the case where said focusing lens group has not been previously moved to said in-focus position when said switch is turned ON, said controller does not limit said range of movement of said focusing lens group in said focus search process to said narrow range.

7. The autofocus camera according to claim 4, wherein, in the case where said face recognition device has not previously recognized said face image when said switch is turned ON, said controller does not limit said range of movement of said focusing lens group in said focus search process to said narrow range.

8. The autofocus camera according to claim 4, further comprising a memory in which image data on said object image that is captured by said image pickup device is stored,

wherein said controller stores said image data in said memory immediately after said autofocusing system moves said focusing lens group to said in-focus position following said recognition of said face image by said face recognition device, and

wherein, upon said switch being turned ON afterwards, said controller compares said image data currently captured by said image pickup device with said image data stored in said memory and does not limit said range of movement of said focusing lens group in said focus search process to said narrow range if a degree of matching between said current image data and said image data stored in said memory is lower than a predetermined degree.

9. The autofocus camera according to claim 8, wherein said image data, which is stored in said memory, comprises the pattern of an entire image based on said image data, and wherein said controller compares said pattern of said entire image based on said image data currently captured by said image pickup device with said pattern of said entire image stored in said memory.

10. The autofocus camera according to claim 4, wherein said controller does not limit said range of movement of said focusing lens group in said focus search process to said narrow range if the number of face images recognized by said face recognition device is unequal to that recognized before said switch is turned ON when said switch is turned ON.

11. The autofocus camera according to claim 4, wherein said controller does not limit said range of movement of said focusing lens group in said focus search process to said narrow range if a difference between a current object brightness and an object brightness at a time when said autofocusing system operates last time is greater than a predetermined value when said switch is operated.

12. The autofocus camera according to claim 4, wherein said controller does not limit said range of movement of said focusing lens group in said focus search process to said narrow range if a central position of said face image recognized by said face recognition device upon said switch being turned ON is within a predetermined range with a center thereof coincident with a central position of a current face image recognized by said face recognition device.

13. The autofocus camera according to claim 1, further comprising a second switch which is turned ON after said switch is turned ON,

wherein, upon said second switch being turned ON, said image pickup device is activated to capture said object image at each of said plurality of different positions of said focusing lens group, and image data on said object images thus captured is stored in an image memory.

14. The autofocus camera according to claim 1, wherein said switch is turned ON upon a release button of said autofocus camera being depressed half way.

15. The autofocus camera according to claim 13, wherein said switch and said second switch are turned ON upon a release button of said autofocus camera being depressed half way and fully depressed, respectively.

16. The autofocus camera according to claim 1, wherein said focusing lens group is moved along said optical axis from one to the other of a near extremity and a far extremity in said focus search process.