| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a high-pressure discharge lamp lighting device which can stabilize an arc rising-point position of a discharge lamp and can restrain deformation of an electrode when the high-pressure discharge lamp having a mercury sealed amount of 0.20 mg/mm<SP>3</SP>or more is operated at extremely low power. <P>SOLUTION: The high-pressure discharge lamp 10 is lighted by supplying power from a lighting device having a step-down chopper circuit 1 and a full bridge circuit 2. The discharge lamp 10 is lighted by supplying rectangular wave AC current to the discharge lamp 10 in the case of rated lighting and lighting at dimming power (about 60-80% of power to the rated power). Furthermore, in the case of standby power lighting of 0.5×P (W) or below to the maximum operation power P (W), when a first polar driving period of the rectangular wave AC current is set up to be Ta (second) to the discharge lamp 10 and a second polarity driving period of the rectangular wave AC current is set up to be Tb (second) to the discharge lamp 10, the discharge lamp 10 is lighted by supplying the rectangular wave AC current at a driving period wherein the second polarity driving period Tb becomes Tb≤5 ms and a ratio of the driving periods becomes Tb/Ta≤0.1. <P>COPYRIGHT: (C)2011,JPO&INPIT |
