| 摘要 |
PURPOSE:To attain remarkable reduction of current consumption by stopping forcibly the projection of an infrared-ray for range finding when an image pickup lens is driven. CONSTITUTION:An infrared-ray LED driver 27 receives an output produced from two clock generators 40, 41 and allows an infrared-ray LED26 to output a modulation frequency of the infrared-ray for range finding. Moreover, an arithmetic section 31 outputs a voltage VF proportional to a reciptocal of a distance to an object subjected to be range finding by an optical current of an optical position detector 30. On the other hand, an amount of movement of a focus control mechanism 39 giving a movement to a focusing lens group is detected by a lens encoder 36, from which a position detection signal VL is outputted. A comparator 33 compares the VF and the VL and detects a dissidence signal (the control mechanism 39 is moving), then the comparator outputs a light emission control signal CK5, which is activated to the LED drive device 27 thereby stopping forcibly the projection of the infrared-ray for range finding. |
