| 摘要 |
PROBLEM TO BE SOLVED: To smoothly return a backlight to normal brightness when a video signal is input while preventing useless power consumption of the backlight when the video signal is not input from an external input terminal side for connecting an external device. SOLUTION: This liquid crystal television is provided with an inverter circuit 28 provided with resistors R5, R6, R7 and R8 for determining the current value of tube current to be supplied to a cold cathode fluorescent tube of the backlight 26 to supply ac voltage to the cold cathode fluorescent tube, a transistor Q14 whose emitter and collector are connected to both ends of the resistor R6, a transistor Q13 whose emitter and collector are connected to both ends of the resistor R7, and a microcomputer 22 having a control terminal connected to the bases of the transistors Q13 and Q14, wherein the microcomputer 22 outputs voltage of a low level to the control terminal when detecting a synchronizing signal in a video signal input to a video signal processing part 12, and outputs voltage of a high level to the control terminal after the elapse of a prescribed time when detecting no synchronizing signal. COPYRIGHT: (C)2008,JPO&INPIT
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