| 摘要 |
<P>PROBLEM TO BE SOLVED: To suppress noise generated immediately after a state where the lighting of an electrodeless discharge lamp can not be kept is changed over to a state where the lighting can be kept while the electrodeless discharge lamp is being lit with light modulation. <P>SOLUTION: By setting a drive frequency of a high-frequency power circuit 5, a light dimming control circuit 6 of this electrodeless discharge lamp lighting device 1 controls the frequency of the high-frequency voltage applied to an induction coil 4 wound around a magnetic core 3 and inducing an induction electric field in the electrodeless discharge lamp 2 in a lighting period in which the electrodeless discharge lamp 2 keeps lighting while the electrodeless discharge lamp 2 is being lit with light dimming, a non-lighting period in which the electrodeless discharge lamp 2 can not keep the lighting, and a re-ignition period immediately after the non-lighting period is changed over to the lighting period, and thereby varies the value of the high-frequency voltage. The light dimming control circuit 6 sets the frequency of the high-frequency voltage in the non-lighting period at a value making the high-frequency voltage in the re-ignition period constant, in a frequency characteristic of the high-frequency voltage of the re-ignition period previously measured by applying a high-frequency voltage having a different frequency in the non-lighting period. <P>COPYRIGHT: (C)2009,JPO&INPIT |
