DISCHARGE TUBE LIGHTING DEVICE, EXPOSING DEVICE, AND LIQUID CRYSTAL DISPLAY DEVICE

摘要

PURPOSE:To prevent sound emission from a winding component of a discharge lamp lighting device when dimming by means of PWM control takes place. CONSTITUTION:A discharge lamp lighting device on high frequency inverter system is structured so that a coil L21 is installed in mutual induction coupling with a choke coil L11 and the inductance component of this coil L21 is shortcircuited via a diode D21. This achieves reduction of the booming sound (noise) generated from the choke coil L11 when a transistor Q11 as a switching means is installed on the primary side of an inverter transformer T and the dimming with PWM control is performed.