LIGHTING SYSTEM

摘要

PROBLEM TO BE SOLVED: To provide an inexpensive and easily miniaturizable lighting device of a discharge lamp capable of reducing application stress to electronic components by suppressing a ringing voltage in light modulation, in a lighting system using an inverter for modulating light of the discharge lamp by PWM control. SOLUTION: This lighting system carries out light modulation of the discharge lamp FL by controlling an on/off ratio of a light-modulating switching element Q3 for stopping and restarting oscillation operation of the inverter 1. The light-modulating switching element Q3 is inserted in a power feed passage from a D.C. power source DC to the inverter 1; a time constant is provided for rise of the output of the inverter 1 with respect to the on/off of the switching element Q3; and a capacitor C3 for softly starting the inverter 1 is installed between the switching element Q3 and the inverter 1. COPYRIGHT: (C)2005,JPO&NCIPI