| 摘要 |
PROBLEM TO BE SOLVED: To provide a discharge lamp lighting device so devised that an emitter-less initial state of a lamp is not detected. SOLUTION: The discharge lamp lighting device is provided with a discharge lamp lighting means 2 for supplying power to and lighting a discharge lamp 6 in alternate current, a direct current increment cutting means 4 connected between the discharge lamp lighting means and the discharge lamp for cutting a direct current increment, a direct current voltage detecting means 8 for detecting a direct current voltage component of the discharge lamp, and an emitter-less state detection means 9 for detecting an emitter-less state that happens at end of life of the discharge lamp, when a voltage value of the direct-current voltage component detected by the direct current voltage detecting means is outside the range of reference voltages V1, V2 and that, for a long period of time. Further, the device is provided with an output converting means 8B for changing and outputting an input at a required output level so as to have the discharge lamp lighting means 2 normally operate with the discharge lamp 6 as not in an emitter-less state, when the voltage value of the direct current component detected by the direct current voltage detecting means 8 is outside the range of the reference voltages V1, V2, and that for only a short period of time. COPYRIGHT: (C)2006,JPO&NCIPI |
