PURPOSE: To let accurate exposure controlling be performed automatically by cutting off exposure on photoreceptor when the exposure of photoelectric transducers which receive the reflected light or transmitted light of a half mirror in exposure system reaches a preset value.
CONSTITUTION: Light images of the original 10 are projected to a photoreceptor 1 and photoelectric transducers 141 thru 14n. The output signals of the respective photoelectric transducers 141 thru 14n are integrated by capacitors 151 thru 15n respectively and when the charge voltage of any of the capacitors 151 thru 15n reaches a reference voltage Vr, the voltage of a high level 1 appears in the output of a comparator 16, by which the thyristors 171 and 172 of a lighting cutoff circuit 17 are conduction-triggered and the currents to be flowed to flash lamps 8 and 9 are thereby shunted by resistances R1 and R2 respectively, then light emission of the flash lamps 8 and 9 stop.
MOCHIZUKI NOBUO
TABATA YUKIO
| JPS4853731A | 1973-07-28 |