Patent ID: 8077140

Claim:
A liquid crystal display device comprising: a liquid crystal panel module including a liquid crystal display panel and a backlight; a first circuit board that receives an external voltage from an external power supply through a power supply line; a second circuit board connected to said liquid crystal display panel; a third circuit board including first and second output terminals connected to said backlight; a rectifier circuit that rectifies said external voltage; a smoothing circuit that smoothes the voltage rectified by said rectifier circuit by switching operation; a first transformer that converts the voltage smoothed by said smoothing circuit into a first internal voltage; a voltage converter that converts said first internal voltage into a second internal voltage that is lower than the first internal voltage; a switching circuit that performs switching on the first internal voltage produced by said first transformer or the voltage smoothed by said smoothing circuit; a second transformer that converts an output voltage of said switching circuit into first and second drive voltages to cause the first and second drive voltages to be output from said first and second output terminals; and a panel drive circuit that is provided in said second circuit board and is operable by said second internal voltage to cause video to be displayed on said liquid crystal display panel, wherein said first and second output terminals are connected to said backlight through first and second conductor wires, respectively, and said rectifier circuit and said voltage converter are provided in said first circuit board, said switching circuit and said second transformer are provided in said third circuit board, and said smoothing circuit and said first transformer are provided in either said first circuit board or said third circuit board.