| 摘要 |
<p>A focus area change circuit is provided with a vertical comparator (50) which compares coincidence of count values of a vertical counter (45) with designated vertical positions of a focus area and a horizontal comparator (51) which compares count values of a horizontal counter 49 with designated horizontal positions. A sampling pulse generaor (52) generates sampling pulses on the basis of vertical and horizontal comparison outputs, which are respectively expanded for generating expansion sampling pulses. A selection circuit (56) selects the sampling pulses or the expansion sampling pulses so that a sampling circuit (32) samples outputs of a video camera on the basis of the sampling pulses or the expansion sampling pulses as selected. A focus motor is controlled to maximize the sampling outputs. Thus, the sampling pulses or the expansion sampling pulses are selected in response to the state of the object of image formation, thereby to enable selection of the focus area.</p> |
