| 摘要 |
PURPOSE:To obtain the automatic focus adjustment device which has no focus tracking delay and is stable. CONSTITUTION:This automatic focus adjustment device puts a focus lens 25 in focus under the command of a microcomputer 13 by using a servo circuit 11, a linear motor 10, and a master sensor 12. This device has a normal mode and a high-speed mode as to the moving speed of the focus lens 25; and the normal mode changes to the high-speed mode when the focus lens when a subject is close shifts in position faster than a specific variation pattern and the high-speed mode changes to the normal mode when the maximum position shift width of the focus lens in each specific time interval becomes less than a specific value. Consequently, the high-speed mode is entered when the subject approaches a camera faster than a constant speed, so there is no focus tracking delay in a short-distance state; and the normal mode is entered immediately when the subject comes to a short-distance point and becomes stationary, so the focusing is stabilized. |
