| 摘要 |
PURPOSE:To start up a discharge lamp lighting unit quickly from the start of lighting by deciding the relation between lamp voltage and a lamp current as lamp current control propertly. CONSTITUTION:A start discharge detection means 9 detects start discharge, and it sends this signal to the timer circuit 72 of a lamp current control means 7. The circuit 72 counts specified time from this signal input. It outputs a signal to a processing means 71 when it has counted up, and the means 71 stores the lamp voltage from a voltage detection means 6 as the final voltage. And, this controls the lighting, selecting the lamp control property being decided from the relation between lamp voltage and currents, from a command current table 73, based on this stored value. Moreover, at lighting of a new discharge lamp, the lamp final voltage is unclear, so lighting is controlled, selecting the minimum power control property of made power from the table 73, to avoid the overpower lighting in the vicinity of the lamp final voltage. Hereby, ideal quantity of light emission can be gotten. |
