| 摘要 |
PROBLEM TO BE SOLVED: To provide a boost technique suitable for high-speed repeat emission in an electronic flash device. SOLUTION: This invention is provided with a flash tube, a power supply part, a switching element and a boost circuit. The boost circuit is provided with a main diode DM and multi-stage-connected boost blocks U1, U2. A charging circuit CH1 in the boost block U1 charges a boost capacitor C1 when the switching element is cut off and generates a reversal voltage in the boost capacitor C1 when the switching element is on. A reversal connection circuit NV1 of the boost block U1 transmits the reversal voltage to the boost block U2. A charging circuit CH2 of the boost block U2 generates double reversal voltage at other end of the boost capacitor C2 when the reversal connection circuit NV1 is on and forms a charging path between an end of the boost capacitor C2 and the power supply part when the reversal connection circuit NV1 is blocked for charging the boost capacitor C2. The reversal connection circuit NV2 of the boost block U2 applies the double reversal voltage to the negative electrode of the flash tube. COPYRIGHT: (C)2006,JPO&NCIPI |
