Patent ID: 7301289
Filing Date: 2007-11-27
Classification: H05B

Abstract:
1. A discharge lamp lighting device for lighting a discharge lamp having a pair of main discharge electrodes facing each other, comprising: a power supply circuit which supplies power to the discharge lamp; a current breaking switch circuit which breaks a current flowing through the discharge lamp; and a modulation control signal generating circuit to which an output current modulation instruction signal is input, wherein the power supply circuit includes a capacitor which stabilizes an output voltage of the power supply circuit, an output current detecting unit which detects an output current of the power supply circuit to generate an output current detecting signal, an output current error calculating circuit which calculates an error between the output current detecting signal and an output current target signal indicating a control target value with respect to the output current detecting signal, and a power supply driving circuit which defines the capability of the power supply circuit on the basis of the output of the output current error calculating circuit, and when the output current modulation instruction signal is activated, the modulation control signal generating circuit holds at least one of an output signal of the output current error calculating circuit and the output current detecting signal to stop the capacitor from being charged and to turn off the current breaking switch circuit.