| 摘要 |
<P>PROBLEM TO BE SOLVED: To reduce power loss in a power supply portion, when supply voltage for driving a backlight is generated in, for example, a liquid crystal display. <P>SOLUTION: A main power circuit and an inverter circuit (or DC-DC converter) are connected in parallel with an input voltage generating means that rectifies and smoothes commercial alternating-current power. At this time, the inverter circuit (or the DC-DC converter) is provided with an isolation transformer that has a primary winding formed on the primary side on which it is not insulated from the commercial alternating-current power and a secondary winding formed on the secondary side. The direct-current input voltage is inputted on the primary side and power conversion is carried out, and thereby the voltage output is obtained on the secondary side of the isolation transformer. Thus, the number of power conversion stages for supplying power to a back light portion connected to the inverter circuit (or DC-DC converter) is left out by one, as compared with the conventional cases, and as a result, power loss in the power supply portion can be reduced as compared with the conventional cases. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
