| 摘要 |
PURPOSE:To attain a focusing operation for an object at a near distance by judging that the object is present at the near distance, and moving a zoom lens to a wide angle side by using the low-pass frequency components of a luminance signal. CONSTITUTION:When a focal point is not detected at the zoom position at a telephoto side, a control circuit 5 switches a switch 403 to an LPF 402 side, and extracts the low-pass frequency components of a luminance signal Y. At the time of judging that the object is present at the near distance, the circuit 5 switches the switch 403 in order to obtain a focus evaluation value (y), and drives a zoom motor 8 by a motor driver 7 in order to automatically move a variator 102 to the wide angle side. At that time, when a master lens 104 is positioned at an end point at the near distance side, it necessarily passes the focal point, so that the focal point can be detected by monitoring the evaluation value (y) during a zoom back. Thus, even when the object is changed at the near distance, the focusing operation can be speedily continued without any error. |
