| 摘要 |
PURPOSE:To prevent malfunction by emitting a detection signal and irradiating an object by causing a luminous body to emit light and measuring the distance by the detection signal thereof when the voltage of a capacitor rises above a prescribed level. CONSTITUTION:When a switch S1 is closed and if the accumulated voltage of a capacitor 30 is sufficient, a high level signal is outputted from a voltage detecting circuit 64, and the capacitor 30 is discharged through a light emitting diode 70 via a storage circuit 66, a one-shot 56 and a transistor 38, whereby the object is irradiated. The reflected light thereof is imaged via a lens 5 on one of photoelectric transducers 72-79, and the outputs of photoelectric conversion circuits 82-88 are compared with the voltage of a voltage source 100. When they exceed said voltage, the high level signals from comparators 92-98 are outputted and these signals are taken into registors 102-108 according to the pulses from the one-shot 56, so that automatic focusing is accomplished by a device 62 through the conduction of a transistor 60. Thereby, malfunction is prevented. |
