Flash device with automatic light emission regulation

摘要

Flash light is repeatedly emitted in a pulse state by intermittently turning on and off an IGBT (31). The flash light reflected by a subject is received by a phototransistor (18) to integrate a received light amount with a capacitor (35). 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.