Flashing device of an automatic light-regulation type

摘要

Flash light is repeatedly emitted in a pulse state by intermittently turning on and off an IGBT. The flash light reflected by a subject is received by a phototransistor to integrate a received light amount with a capacitor. While the IGBT is turned off, a charging voltage of the capacitor is converted to digital data. Based on the obtained data, it is judged whether emitting the flash light is stopped or not.