| 摘要 |
<p>An auto-focus device capable of focusing on an object in a short time even if the object gets out of focus significantly at the time of zooming. The auto-focus device comprises a camera lens having a zoom lens and a focus lens, an image input means for imaging the optical image of an object through the camera lens and outputting an image signal, a means for calculating an evaluation value from the high frequency component of the image signal, and a control means performing a first processing (step S204) for searching the focus position of the object while oscillating the focus lens in the longitudinal direction of the object when the zoom lens is zooming, and performing a second processing (step S206) for searching the focus position of the object by stopping the first processing when a decision is made that the evaluation value is not higher than a first predetermined level for a first predetermined time during the first processing (step S202) and moving a focus lens position over the entire movable range.</p> |
