| 摘要 |
PROBLEM TO BE SOLVED: To provide a fluorescent tube driving method capable of stabilizing a current flowing to a fluorescent tube, and its device. SOLUTION: Based on a voltage drop value generated in a shunt resistor Rs corresponding to a total current Io including both a leakage current Ile caused by a distribution capacity present between adjacent conductors such as a chassis and a reflecting plate constituting a backlight unit, and the fluorescent tubes 3, and a current Iout flowing to the fluorescent tubes 3, a PWM control part 4 generates a PWM-controlled transistor drive signal for keeping the total current Io constant, and supplies it to each of bases of switching transistors Q1 and Q2 to turn on/off the switching transistors Q1 and Q2 and control periods thereof. For the voltage drop value corresponding to the total current Io inputted to the PWM control part 4, compensation according to temperatures of the fluorescent tubes 3 is carried out by detecting the temperatures of the fluorescent lamps 3 by a temperature detection element Rt. COPYRIGHT: (C)2009,JPO&INPIT |
