| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a light emission control circuit for a flashing device controlling so that emitted light quantity including overrun light quantity may be target emitted light quantity by using a comparatively inexpensive analog type photometry circuit. <P>SOLUTION: The light emission control circuit for the flashing device has: a photosensor (PD) receiving emitted light from a light emitting tube; a capacitor (C) integrating a photoelectric current output from the photosensor; and a light emission stop signal output means (CMP) comparing voltage generated from the capacitor with comparison voltage (Vref) and outputting a light emission stop signal when the voltage generated from the capacitor exceeds the comparison voltage, predicts the overrun light quantity obtained until light emission by the light emitting tube is finished after the light emission stop signal is output from light emission target light quantity, and sets the comparison voltage so that total emitted light quantity including the overrun light quantity may be the target emitted light quantity. <P>COPYRIGHT: (C)2007,JPO&INPIT</p> |
