LIGHT DEVICE FOR DISCHARGE LAMP

摘要

PROBLEM TO BE SOLVED: To provide a lighting device for a discharge lamp, which can reliably detect no load without causing a cost increase. SOLUTION: A high frequency power source 1 to supply a high frequency voltage to a discharge lamp 3 by connecting the discharge lamp 3 to its output side through a load wire 2 and a no load detecting circuit to detect the presence of a filament of the discharge lamp by forming a current passage with at least the filament of the discharge lamp 3 and resistors R1-R3 between both terminals of an external power source are equipped, and a connecting point of the high frequency power source 1 and the no load detecting circuit is disposed in the neighborhood of the high frequency power source 1.