| 摘要 |
PROBLEM TO BE SOLVED: To enable lifetime detection of an electrodeless discharge lamp in an electrodeless discharge lamp lighting device having a frequency control circuit to make output constant. SOLUTION: In the electrodeless discharge lamp lighting device provided with an induction coil 2 installed in the vicinity of the electrodeless discharge lamp 1, a high frequency power supply circuit 3 to supply high frequency electric power to the induction coil 2, and the frequency control circuit 5 to control a driving frequency of the high frequency power supply circuit 3 so that at least either one of output electric current or output voltage of the high frequency power supply circuit 3 will have a desired value in lighting the electrodeless discharge lamp 1, it has the lifetime detection circuit 7 to judge it as the lifetime of the electrodeless discharge lamp 1 if it deviates from a preset tolerance range of the driving frequency. COPYRIGHT: (C)2006,JPO&NCIPI |
