| 摘要 |
PROBLEM TO BE SOLVED: To provide an auto-focus device which can perform accurate auto-focusing (AF) even when a lens does not move with a uniform speed, and an imaging apparatus having the same, and an auto-focus method using the same.SOLUTION: An imaging element 4 is exposed while the position of a lens of an imaging optical system 1 is continuously changed. By the exposure, the contrast value of an image is calculated by a contrast value calculation circuit 10. An average value of three or more lens positions of the imaging optical system 1 during the exposure is calculated by an average value calculation circuit 14. The average value and the contrast value are associated with each other, and a peak of the contrast value is detected. When the peak of the contrast value is detected, the imaging optical system 1 is driven to a lens position corresponding to the peak. |
