| 摘要 |
PROBLEM TO BE SOLVED: To provide an autofocus device capable of improving the sharpness of a peripheral image at a just focused position. SOLUTION: Incident light from an object image is made incident on an imaging device 7 through a focus lens 1 and photoelectrically converted to obtain video signal voltage S2. The predetermined high band frequency focus voltage E is detected from the video signal voltage S2, and the focus lens 1 is driven by a control circuit 3 through a pulse motor 2 and is moved to a position where the maximum focus voltage is obtained (just focused position). Then, the control circuit 3 refers to defocus amount by which the maximum contrast value of an image point by a light beam in a meridional direction corresponding to a zoom position stored in correction data 13 in advance is obtained, and a position correction value is obtained from the defocus amount by arithmetic calculation. By driving the pulse motor 2 again and finely correcting the position of the focus lens 1, the sharpness of the image is improved. COPYRIGHT: (C)2006,JPO&NCIPI |
