| 摘要 |
PROBLEM TO BE SOLVED: To shorten a period of time required for automatic focus scan. SOLUTION: First, a face is detected by a focus lens located in a position (C). When the face is detected, the depth of a field is detected relative to the face detection (range (a): 2 m to 8 m) from a current diaphragm value. Then, a lens diaphragm is driven for obtaining a diaphragm open value. After the diaphragm is driven, the face is detected. Since the diaphragm is driven in an opening direction, the depth of a field is made shallow to, for example, 4 to 6 m (range (c)). The final focal position (B) is a the range (c) of 4 to 6 m in the depth of a field. Therefor, a scan range by an automatic focus is limited to the range (c) of 4 to 6 m in distance which corresponds to the depth of the filed of the subject. Consequently, the scan range is reduced from the scan range (a) determined by the original diaphragm value to a new one (c). This enables higher automatic focus control. COPYRIGHT: (C)2010,JPO&INPIT |
