| 摘要 |
PROBLEM TO BE SOLVED: To omit unnecessary focusing operation by deciding the possibility of focusing by automatic focusing(AF) and stopping focusing operation when it is judged that the focusing is impossible as to a device and a method for AF which use an evaluated value calculated from the high-frequency component of an image signal. SOLUTION: A focusing area is searched (roughly) at relatively large search intervals and the evaluated value obtained here is used to decided the possibility of focusing. For the decision making, two thresholds (T1>T2) are set; when the maximum evaluated value Afmax is larger than the large threshold T1, it is judged that the focusing is possible and the focusing area is searched (in detail) at smaller search intervals, and when the maximum evaluated value is smaller than the small threshold T2, it is judged that the focusing is impossible and the detailed search is inhibited. When the maximum evaluated value is between the small threshold and large threshold, it is decided whether the evaluated value of the rough search has a peak; when the evaluated value has no peak, the 2nd search is inhibited and when the evaluated value has a peak, the 2nd search is made. |
