| 摘要 |
<p>PROBLEM TO BE SOLVED: To control an arc in a straight condition for the whole lighting time by providing a lighting control means constituted so that a sine wave generating means and a high voltage generating means can function by partially using the same circuit in common with each other. SOLUTION: When a lighting switch 27 is turned on, DC voltage is supplied to a control means 17, and a standby condition of a series of control operation up to reaching stable lighting from a lights-out condition of a discharge lamp 19 is secured. When the lamp 19 is lighted, first of all, it is necessary to impress high voltage of about 25kV between discharge terminals in the interior of the lamp 19. Then, voltage is boosted to about 300V by an electric power control circuit 171, an FET 20, a DC/DC converter 14, a diode 15 and a capacitor 16. Next, a capacitor 252 is charged with voltage from a high voltage control circuit 251 in a high voltage generating means 25, and high voltage is impressed between the discharge terminals of the lamp 19 by a high voltage transformer 22. As a result, the lamp 19 starts discharge, and is lighted.</p> |
