Patent ID: 9030130
Filing Date: 2015-05-12
Classification: H05B,Y02B

Abstract:
1. A method for lighting a high-pressure discharge lamp having an arc tube enclosing a light-emitting material and a pair of electrodes disposed opposite each other, the method being used in a lighting device provided with a power supply unit operable to supply power to the high-pressure discharge lamp and a control unit operably configured to control the power supply unit by selectively performing (i) constant power control to cause the power supply unit to maintain lamp power at a constant power at which lamp current is equal to or less than a current limit (Ia) and (ii) constant current control to cause the power supply unit to maintain the lamp current at a constant current, the method comprising the steps, performed by the control unit, of until the lamp power reaches a predetermined wattage (P until a predetermined time passes, performing constant power control to cause the power supply unit to maintain the lamp power at a predetermined wattage (P after the predetermined time passes, performing constant power control to cause the power supply unit to maintain the lamp power at wattage (Pr).