| 摘要 |
PROBLEM TO BE SOLVED: To provide a discharge lamp lighting device capable of preventing drop of luminous flux of a discharge lamp in emergency lighting and of extending emergency lighting by using, in emergency lighting in common, a regular lighting device for controlling the lighting of the discharge lamp with constant power in normal lighting. SOLUTION: A D.C. voltage obtained from a rectifier 13 for providing a direct current by rectifying A.C. power is normally raised by a step-up circuit 14, and an inverter circuit 15 converts the raised voltage to a high-frequency voltage to light the discharge lamp 17 with high frequency. An emergency power charging circuit 18 charges an emergency power source 21 with D.C. power obtained from the rectifier 13. An emergency power step-up circuit 22 raises the voltage of the emergency power source 21 in emergency. A lighting control part 27 executes a normal lighting operation for lighting the discharge lamp with constant power at high frequency by converting the voltage raised by the step-up circuit 14 to a high-frequency voltage in a normal time and executes an emergency lighting operation for dimming and lighting the discharge lamp 17 with constant power by converting the voltage from the emergency power step-up circuit 22 to a high-frequency voltage in an emergency time. COPYRIGHT: (C)2007,JPO&INPIT |
