LIGHTING DEVICE FOR PLURAL DISCHARGE LAMPS

摘要

PURPOSE:To compensate the dispersion in luminance or difference in deterioration of respective discharge lamps and illuminate the whole surface with uniform brightness. CONSTITUTION:A DC power source DC and a transistor Q1 driven by an inverter controller 1 are connected on the primary side of a transformer T1. A series circuit of a plurality of cold cathode discharge tubes CFL1-CFL3 with transistors Q2-Q4 is connected in parallel on the secondary side of the transformer T1. Monostable multivibrators MS1-MS3 for driving the transistors Q2-Q4 are triggered in the order by the output of a decoder 17. The ON times of MS1-MS3 are set by variable resistors RV1-RV3 according to the luminances of the respective discharge tubes.