| 摘要 |
PROBLEM TO BE SOLVED: To provide a lighting device by which a discharge lamp reaching the last stage of the service life by no emission can be lighted by a comparatively simple control means by providing a control circuit to impart an oscillation control signal in common to respective driving control means. SOLUTION: When emission disappears from the filament of a discharge lamp 11, approaching its service life, and discharge lamp voltage increases, an emissionless detecting signal is supplied to a corresponding driving control means 14 from a corresponding emissionless detecting means 13. Output of an inverter circuit 12 corresponding to the emissionless discharge lamp 11 is stopped. In this way, the discharge lamp 11 becoming emissionless is put out, and the possibility of disrupting the corresponding inverter circuit 12 is avoided. Since a control circuit 15 imparts an oscillation control signal in common to respective inverter circuits 12 through respective driving control means 14, oscillation frequencies of respective inverter circuits 12 become the same, and a condition of proximally interfering with an infrared ray remote control signal 17 can be easily avoided, and adverse effect on remote control can be reduced. |
