Patent ID: 8531124
Filing Date: 2013-09-10
Classification: H02M,H05B,Y02B

Abstract:
1. A high pressure discharge lamp lighting device comprising: a boost chopper circuit that boosts a DC input voltage to a desired DC output voltage; a boost chopper control circuit that controls the boost chopper circuit to allow a DC output voltage of the boost chopper circuit to coincide with the desired DC output voltage; a power conversion circuit that converts the DC output of the boost chopper circuit into power necessary to start and light a high pressure discharge lamp; a power conversion control circuit that controls the power conversion circuit to adjust the power to be supplied to the high pressure discharge lamp; and a control power supply circuit that supplies a control power for an operation to at least the boost chopper control circuit, wherein the boost chopper circuit includes an inductor, a switching element that connects and disconnects a current flowing through the inductor, a rectifier that rectifies the current flowing out from the inductor, and a smoothing capacitor that smoothes the current rectified by the rectifier, the control power supply circuit includes a winding magnetically coupled to the inductor of the boost chopper circuit, and obtains the control power by rectifying and smoothing an induced voltage induced in the winding, the boost chopper control circuit detects the DC output voltage of the boost chopper circuit, and performs feedback control so as to allow a detected value of the DC output voltage to coincide with a target value thereof, at a starting time of the high pressure discharge lamp, the boost chopper control circuit controls the DC output voltage of the boost chopper circuit to coincide with a first DC output voltage, after the high pressure discharge lamp is started, the boost chopper control circuit allows the output voltage of the boost chopper circuit to coincide with a second DC output voltage lower than the first DC output voltage after the high pressure discharge lamp is started, and in an event of switching the DC output voltage of the boost chopper circuit from the first DC output voltage to the second DC output voltage, the boost chopper control circuit operates the boost chopper circuit intermittently thereby the DC output voltage of the boost chopper circuit is switched to a third target value corresponding to a third DC output voltage lower than the first DC output voltage and higher than the second DC output voltage or to a third detected value corresponding to the third DC output voltage, and thereafter, the DC output voltage of the boost chopper circuit is switched to a second target value corresponding to the second DC output voltage or a second detected value corresponding to the second DC output voltage.