| 摘要 |
PURPOSE: To prevent electric discharge from being stopped even when the electric discharge is not continued in the case of the light emission of a flash electric discharge tube is controlled by turning on/off a switching element. CONSTITUTION: An IGBT 24 which is the switching element is turned on by a driving circuit constituted of a first pulse generator 36, a second pulse generator 38, a photodiode 33, a resistance 34 and an AND gate 37, and when an SRC 8 is turned on, a trigger means constituted of a trigger transformer 5, a capacitor 6, the SCR 8 and the resistances 7 and 9 is actuated, so that the flash electric discharge tube 22 emits light by the electric discharge of a main capacitor 3. Then, the light emission of the electric discharge tube 22 is controlled by repeating turning on/off of the IGBT 24, but when the IGBT 24 is turned on, an electric discharged current is detected, and a transistor 12 is turned on but the SCR 8 is not turned on, and then the electric discharge tube 22 is not triggered, and on the other hand when the transistor 12 is turned off, the trigger means is operated, so that the electric discharge of the electric discharge tube 22 is restarted. |
