| 摘要 |
PURPOSE:To calculate an accurate focal distance in a short time without increasing the number of light projecting and light receiving elements, and to attain the miniaturization and the reduction of a cost. CONSTITUTION:When a light projecting means 2 and a light receiving means 3 are moved in a forward direction in front of an object by a scanning driving means (stepping motor) 4 which is controlled by a control circuit 6, light reflected on the object is received by the light receiving means 3 and the peak value of light intensity is detected by a peak detection circuit 8. A position where the peak value is detected is confirmed by counting the driving pulse of the scanning means 4 by a counter 7 and so on, and then, the position is stored in a storage circuit 9. The movement of the light receiving means 3 in a backward direction is stopped at the position where the peak value is detected, a distance to the object is measured by a distance calculation circuit 10. A focusing means 11 is driven so as to feed out a lens and so as to focus by a distance signal measured by such a range finder, and then, an exposure means 12 is driven so as to photograph the object. |
