| 摘要 |
PROBLEM TO BE SOLVED: To detect a peak (maximal value) with high probability, even when the contrast of an object image is low. SOLUTION: Regarding the focus detector for detecting a focus using the contrast of the object image, the contrast values of the object image are detected in a plurality of lens positions while moving a focusing lens group 1 of a photographing lens, and when the maximum value and the minimum value of the contrast values are not within a prescribed extent, a 1st prescribed number and a 1st decision value are set, on the other hand, in the case the maximum value and the minimum value of the contrast values are within the prescribed extent, a 2nd decision number exceeding the 1st prescribed number and a looser standard 2nd decision value than the 1st decision value are set, and when the presence of the maximal value is detected, a difference between the detected maximal value and the contrast value in the lens position separated by the amount of the set 1st prescribed number or the 2nd prescribed number across the maximal value is obtained, and when the difference exceeds the set 1st decision value or the 2nd decision value, the aforesaid maximal value is selected. COPYRIGHT: (C)2006,JPO&NCIPI |
