| 摘要 |
PURPOSE:To perform the accurate measurement of distance for an object to be photographed of high luminance, by providing a means to a distance measuring device containing a projecting element and a photodetector to stop a photographing lens at a prescribed point or at a focusing position at the long distance side. CONSTITUTION:When an object to be photographed has high luminance, an operational amplifier OP1 is saturated. Then the fluctuation component of the power supply voltage VCC is delivered as it is from the OP1. This fluctuation component is sampled with sampling pulses phi1 and phi2. Thus the synchronizing detecting output LPO which is opposite to the signal light caused by an ordinary object to be photographed is delivered. In this connection, a magnet Mg2 conducts with the output of a comparator COM and a photographing lens can be stopped at a prescribed position if the reference voltage VV2 is set higher than the output LPO obtained when the OP1 is saturated. When the lens itself has a large depth of field, a magnet Mg1 conducts. And the lens can be stopped at a zone at the long distance side. In such way, the distance can be accurately measured for a camera for an object to be photographed of high luminance. |
