IMAGE PICKUP APPARATUS AND METHOD OF CONTROLLING THE SAME

• US 20110243538A1
• Filed: 01/24/2011
• Published: 10/06/2011
• Est. Priority Date: 04/06/2010
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Morimoto, Yosuke
• Granted Patent: US 8,526,804 B2
• Time in Patent Office: Days
• US Class Current: 396/77
• CPC Class Codes: G02B 7/102 controlled by a microcomputer cameras with interchangeable lenses G03B17/14
• 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 23/634 Warning indications
• CPC Class Codes: H04N 23/635 Region indicators; Field of view indicators
• CPC Class Codes: H04N 23/69 Control of means for changing angle of the field of view, e.g. optical zoom objectives or electronic zooming

Abstract

An image pickup apparatus detects a subject based on an image signal output from an image sensing unit and acquires a size of the detected subject. The image pickup apparatus performs an automatic zooming operation such that a zoom lens is driven so as to increase or decrease the size of the subject so that the size of the subject becomes equal to a reference size of the subject. In a case where the difference between the size of the subject and the reference size has increased beyond a predetermined threshold value and the position of the zoom lens has reached a wide angle end or a telephoto end, the image pickup apparatus resets the reference size to be equal to the current size of the subject.

Claims

1. An image pickup apparatus comprising:

an image sensing unit configured to sense an image of a subject formed by an optical imaging system including a zoom lens and output a resultant image signal;

a subject detection unit configured to detect the subject in an image screen based on the image signal output from the image sensing unit;

a subject size acquisition unit configured to acquire a size of the subject detected by the subject detection unit; and

a controller configured to perform an automatic zooming operation such that the zoom lens is driven to increase or decrease the size of the subject acquired by the subject size acquisition unit so that the size of the subject becomes equal to a set reference size,

wherein in a case where a position of the zoom lens has reached a wide angle end or a telephoto end, the controller resets the reference size to be equal to the size of the subject.

2. The image pickup apparatus according to claim 1, wherein in a case where the difference between the acquired size of the subject and the set reference size has increased beyond a predetermined threshold value, the controller resets the reference size to be equal to the size of the subject.

3. The image pickup apparatus according to claim 1, wherein in a case where the difference between the acquired size of the subject and the set reference size has increased beyond a predetermined threshold value and the position of the zoom lens has remained at the wide angle end or the telephoto end for a continuous time longer than a predetermined threshold value, the controller resets the reference size to be equal to the current size of the subject.

4. The image pickup apparatus according to claim 1, wherein in a case where the difference between the acquired size of the subject and the set reference size has increased beyond a predetermined threshold value and the position of the zoom lens has reached the wide angle end or the telephoto end, the controller makes a determination based on history information of the acquired subject size as to whether a change in subject size is within a predetermined threshold value, and the controller resets the reference size to be equal to a mean value of subject sizes if it is determined that the change in subject size is within the predetermined threshold value.

5. The image pickup apparatus according to claim 1, further comprising a display configured to display a warning when the position of the zoom lens has reached the wide angle end or the telephoto end.

6. The image pickup apparatus according to claim 5, wherein in a case where the controller has reset the reference size to a new value, the display stops displaying the warning.