| 摘要 |
PURPOSE:To decide on a frame smoothly and to speed up focusing drive by driving a photographic lens to a specific focus point in response to the lighting preparatory operation of a light device, and using an auxiliary light emission source and performing the focusing drive. CONSTITUTION:When an AF switch 2 is closed, the output of an AND gate 3 goes up to a level H and a distance measuring unit 8 is held in readiness for operation. The H-level output of the AND gate 3 is applied to a terminal D of an FF20 through an OR gate 22 and the output of an inverter 23 goes up to the level H. Therefore, an AND gate 7 outputs an H-level signal and the range finder unit 8 performs range finding operation. Range finding data is passed through a sample holding circuit 9 and a differential amplifier 14 to supply a driving current to a motor 15, which drives the photographic lens until the output of a differential amplifier 13 coincides with the output of the circuit 9. When the auxiliary light source is used, the output of an AND gate 4 goes up to the level H and focusing drive is carried out similarly. |
