| 摘要 |
PURPOSE:To shorten rise time, and flatten light output by detecting an electric current and voltage impressed on a discharge lamp, and controlling the electric current and the voltage according to an added value of a detecting result so that the added value coincides with a reference value. CONSTITUTION:DC voltage is supplied from DC electric power supply 12 by a DC-DC converter 11, and a high frequency pulse is impressed on a discharge lamp 15 by a PWM regulator 13 and a full bridge circuit 14. Respective ones of these impression voltage and impression electric current are detected by a voltage detecting circuit 16 and an electric current detecting circuit 17, and a detecting result is added by an adder 30, and they are controlled by the regulator 13 so that an added result coincides with a prescribed reference value. A high intensity discharge lamp lighting circuit whose rise time is short and light output is flat is attained by this feedback electric power control. |
