| 摘要 |
PROBLEM TO BE SOLVED: To obtain an AF device which continues focusing properly even if it becomes temporarily impossible to detect a focusing state during focus adjustment by a phase difference type focus detection means. SOLUTION: A lens drive control part 8 of the AF device does not immediately perform scanning operation when a defocus amount calculation part 6 cannot calculate a defocus amount DF, but performs the operation when contrast information Cnt calculated by a contrast calculation part 4 is less than a predetermined value. The lens drive control part 8 performs the maximum contrast detecting operation by a contrast detecting AF system in a case of a periodic pattern, and further the lens drive control part 8 stops driving a focus lens if the contrast information Cnt is above the predetermined value, the defocus amount DF cannot be calculated, and the contrast information decreases in the processing forwarding during focus lens drive. On the other hand, if the contrast information Cnt does not decrease, the focus lens drive is continued. Also, the focal lend drive is stopped if the contrast information Cnr is above the predetermined value, the defocus amount DF can be calculated, and the contrast information Cnt decreases in the processing forwarding during focus lens drive. COPYRIGHT: (C)2007,JPO&INPIT |
