| 摘要 |
PROBLEM TO BE SOLVED: To prevent the application of overcharge voltage to a main capacitor and the unnecessary charge and discharge of the main capacitor. SOLUTION: The main capacitor is charged with boosted voltage by a boosting circuit in order to make a flash light emitting circuit emit flash light. A 1st voltage detection circuit detects that the charge voltage of the main capacitor attains 1st voltage. A control circuit stops boosting operation by the boosting circuit in response to the detection by the 1st voltage detection circuit. A 2nd voltage detection circuit detects that the charge voltage attains 2nd voltage higher than the 1st voltage. A discharge switch connects the main capacitor to a discharge destination node in response to the detection by the 2nd voltage detection circuit. An interrupting circuit is connected between the boosting circuit and the main capacitor so as to be disconnected in response to the turn-on of the discharge switch. Consequently, the application of the overcharge voltage to the main capacitor and the unnecessary charge and discharge of the main capacitor are prevented. COPYRIGHT: (C)2005,JPO&NCIPI |
