PURPOSE: To realize size reduction by connecting a GTO and a reactor in series with a xenon lamp, a diode and a capacitor between the reactor and the gate of the GTO in series, and a switching element in parallel to the diode, and connecting a turn-on circuit to the gate of the GTO.
CONSTITUTION: A converter 1 charges a main capacitor 2 and a capacitor 14, and when a shutter button is pressed, a trigger pulse is applied to the gate of an SCR5 and the gate of the GTO31, turning on the both. At this time, the capacitor 14 is discharged through the SCR5 to turn on the xenon lamp 9, and a current (i) is flowed from the main capacitor 2 to maintain the light emission. Further, the reactor 32 generates counter electromotive force to charge a capacitor 35. A photodetecting circuit 24 outputs a trigger pulse when its photodetection amount attains to a specific value, and an SCR12 turns on to lead a turn-on current from the gate of the GTO31 through the route of the capacitor 35 and SCR12, so that the xenon lamp 9 does not emit light any more.
HOSHI HITOSHI
KAWASAKI KATSUHISA
