| 摘要 |
PROBLEM TO BE SOLVED: To suitably perform detection of operation abnormality in the occurrence of operational abnormality of either one of a fluorescent lamp while performing dimming by PWM control of two hot cathode fluorescent lamps connected in series. SOLUTION: A resistor pair 13 comprising two resistors 13a, 13b connected in series are parallely connected to the fluorescent lamp pair A comprising fluorescent lamps A1, A2 connected in series between a pair of ac voltage output parts 3a, 3b. A lighting device includes: a means 11 to generate a detection signal in accordance with a potential difference between the middle point 14 of the resistor pair 13 and the middle point 15 of the fluorescent lamp pair A; and a means 12 to detect whether there is operational abnormality in either one of the fluorescent lamps A1, A2 based on the maximum side peak value and the minimum side peak value of the detection signal with an ac voltage impressed on the fluorescent lamp pair A. COPYRIGHT: (C)2009,JPO&INPIT |
