| 摘要 |
PURPOSE:To surely ignite a discharge tube by a method wherein an output of a continuous output setting circuit or an output of a pulse output setting circuit and an output of a stationary ignition pulse output setting circuit are input to a superposed circuit and an output of the superposed circuit is used as a command signal which sets a magnitude of a laser output. CONSTITUTION:Even when a discharge is started or a laser output is turned down, the following are input to a superposed circuit 31: an output of a continuous output setting circuit or an output of a pulse output setting circuit 24; an output of a stationary ignition pulse output setting circuit 29 used to supply high-frequency electric power or a direct-current discharge current so as to be a voltage of larger than a firing voltage of a discharge tube. An output of the superposed circuit 31 is used as a command signal which sets a magnitude of a laser output. Accordingly, the magnitude of the laser output is never influenced even in a continuous mode and a pulse mode; a stationary ignition pulse contributing to a firing discharge of a discharge tube is supplied; accordingly, the discharge tube can be ignited surely. |
