| 摘要 |
PURPOSE:To raise up optical output speedily regardless of a lamp voltage or on/off conditions of lighting, and prevent excessive optical output for a discharge lamp lighting device. CONSTITUTION:When a DC power supply 1 is applied, an inverter circuit 2 oscillates. When an output of the DC power supply 1 reaches a specified voltage, a lighting control circuit 8 receives output of a DC voltage detection circuit 7 and actuates a start circuit 3 for starting a discharge lamp 5. After the discharge lamp 5 is started, output of the DC power supply 1 is controlled by the lighting control circuit 8 in accordance with a lamp voltage when the lamp voltage is lower than a specified voltage, and in accordance with a lighting-off time and a lighting time when the lamp voltage is higher than the specified voltage to set the output larger as the lighting-off time is longer immediately after starting, and set the output gradually smaller as time elapses after starting till lighting at a rated value is achieved. |
