| 摘要 |
PURPOSE:To detect an accurate focusing state, by providing a means where a maximum value of output signals of a photodetecting means consisting of plural photodetectors for receiving lights from an object is divided by the number of photodetectors, which issue signals higher than a prescribed value, to calculate a maximum value of the appreciation index. CONSTITUTION:The light from an object is incident to a photodetector array 16 through a photographic lens, and the outputs of photo diodes 16-1-16-N pass through an AD converter 32 and a maximum value detector 38, and a maximum value of output signal is inputted to an operating storage circuit 40 and a dividing circuit 42. Meanwhile, the operating storage circuit 40 multiplies the maximum value by 0.7 and stores the multiplication result, and a number (n) of photodiodes which output signals exceeding this value is deteted through a comparator 44 and a counter 46, and the maximum signal value is divided by (n) in the dividing circuit 42. A maximum value of the appreciation index is inputted to an actuator 20 through a maximum value detecting circuit 48 and a comparator 50. Since the output distribution of the photodetector array 16 is taken into consideration, an accurate focusing state is detected. |
