| 摘要 |
PURPOSE:To restrict a power loss at a preheating circuit while a discharge lamp is lighted, eliminate need of a high-voltage-proof switch element, and realize a compact size and a high efficiency for a lighting device in a discharge lamp lighting device for lighting a heat cathode type discharge lamp by high frequency waves. CONSTITUTION:A series circuit of a preheating transformer T1 and a switching element Q1 is connected in parallel with one of two smoothing capacitors C1, C2 for forming a chopper circuit for preheating, an output of an inverter 1 is reduced for a predetermined time after turning on a power supply, and action of the chopper circuit is stopped after a lapse of a predetermined time after turning on the power supply. A power loss at the preheating circuit during lighting a discharge lamp can thus be restricted, and a lighting device can be of a high efficiency. The power supply to the chopper circuit is obtained as partial voltages by C1, C2, a high-voltage-proof switching element is not required, thereby the lighting device can be compact. |
