| 摘要 |
PURPOSE:To make it possible to start to pass a discharge holding current constantly at a fixed timing immediately after a main discharge starting current begins to flow and to prevent rapid triggering or slow triggering by providing a current sensor which detects a discharge starting current inside a discharge starting circuit. CONSTITUTION:A current sensor 8 which detects a current flowing inside a closed loop circuit consisting of a capacitor C2, preliminary ionization electrode 3 and main discharge electrodes 4, 5 detects a discharge starting current which flows when discharge of laser gas between the main discharge electrodes 4, 5 begins and sends the signal to a switch 6 as a trigger pulse signal. According to this constitution, if the switch 6 closes, a charge stored in a capacitor C3 is consumed to keep the discharge already made between the main discharge electrodes 4, 5 to attain to laser oscillation. If the time needed to actually start main discharge varies greatly, the discharge holding current flow can be always made most timely. Misfire can be eliminated and a life of a main discharge electrode and laser gas can be improved in this way. |
