Patent ID: 8207688
Filing Date: 2012-06-26
Classification: H05B,Y02B

Abstract:
1. An electric-discharge lamp lighting device, comprising: a power inverter configured to output an AC voltage by receiving electric power from a DC power supply and including at least a switching element and a resonant circuit; a drive circuit configured to drive the switching element; a load connected to an output of the power inverter and connected to at least an electric-discharge lamp; a first frequency controller configured to sweep a switching frequency of the drive circuit so that the output of the power inverter is gradually increased in order to allow the electric-discharge lamp to be started and lit; a second frequency controller configured to detect an output power of the power inverter by a current flowing in the resonant circuit and to control the switching frequency of the drive circuit so that the output power is set to be a target value after the discharge lamp is started and lit; and a lighting detector configured to perform a lighting detection of the electric-discharge lamp by detecting the output of the power inverter, wherein the first frequency controller includes a holding circuit configured to hold the switching frequency just after the lighting detection, when the output power is smaller than the target value at the lighting detection by the lighting detector, and the second frequency controller controls the switching frequency to maintain the output power at a substantially constant value, as the target value, after the output power reaches the target value.