| 摘要 |
<p>PURPOSE:To enable to immediately expose after a power interruption is recovered by providing a circuit for automatically operating a starter when a momentary power interruption of a commercial power source occurs and the power is recovered, and a circuit for inhibiting the operation of its operating circuit when the power interruption time exceeds the prescribed time, thereby shortening an extinguishing time of an ultrahigh pressure mercury lamp due to the momentary power interruption. CONSTITUTION:A power supplied to an ultrahigh pressure mercury lamp 4 is controlled to set power W0 necessary for exposure on the basis of a reference voltage VS from a comparator COM and the detected power of a power detector 24 during a period that a commercial AC power source is normal. When a power source E is interrupted during exposing process, contacts ry11, ry12 are closed by a power interruption detector 51. When the contact ry11 is closed, a capacitor 57 is discharged, the output of a timer IC531 becomes H level, Tr61 is turned OFF, a power capacitor 59 is not discharged, but when the power interruption time is elapsed for the prescribed time T1, Tr61 is turned ON to discharge the capacitor 59. When the power interruption is recovered within T1, the power interruption detected state due to the detector 51 is released, power is supplied from the power source E to a starter 3 to fire a mercury lamp 4.</p> |
