| 摘要 |
PROBLEM TO BE SOLVED: To provide a hot-cathode discharge tube lighting device in which the cause of a fire due to an emitter-less phenomenon is eliminated by shutting off the lighting device by detecting that the hot-cathode discharge tube comes to or is close to the end of its life, by accurately detecting an emitter-less phenomenon even in one-side emitter-less state or both-side emitter-less state of the discharge tube. SOLUTION: In the hot-cathode discharge tube lighting device, positive-side and negative-side current values of a tube discharge alternating current of a discharge tube FL are individually detected (5, 6); when either or both of the current values fall below a preset reference value Vref, a discharge tube lighting function is disabled by cutting off (S) a current flowing in the discharge tube FL or the like. COPYRIGHT: (C)2009,JPO&INPIT |
