| 摘要 |
PURPOSE:To stably dim a discharge lamp by operating a dimming means in response to the level of the high-frequency power when a dimming signal is received during a fade-out action. CONSTITUTION:When a lights-out signal is received from a remote control transmitting circuit 8 while high-frequency power is fed from an inverter circuit 4 and a discharge lamp 5 is lighted with the rated power, an inverter control circuit section 6 gradually increases the oscillation frequency and outputs it to the inverter 4, and the discharge lamp 5 is gradually turned off. When a dimming signal is received during this time, if the high-frequency power is the dimming lower limit level or above, the lights-out action is released, and the normal dimming means is operated. If the high-frequency power is a dimming allowable level less than the dimming lower limit level, the lights-out action is released, the discharge lamp 5 is again preheated and started, the power higher than the dimming lower limit level is fed, then the dimming action is performed. Dimming can be stably performed when the dimming signal is received during the lights-out action. |
