Patent ID: 7289116

Claim:
An electric power unit for driving a display unit, comprising: a first voltage conversion circuit for stepping up an inputted power supply voltage to generate a first output power supply voltage; a first multiplicity of buffer circuits for generating, based on said first output power supply voltage, a group of high output voltages that are lower than said first output power supply voltage; a second multiplicity of buffer circuits for generating, based on a third output power supply voltage, a group of low output voltages; a second voltage conversion circuit for stepping down the highest of said group of high output voltages to generate a second output power supply voltage that is lower than the lowest of said group of high output voltages but higher than the highest of said group of low output voltages; and a third voltage conversion circuit for stepping up said inputted power supply voltage to generate said third output power supply voltage that is lower than the lowest of said group of high output voltages but higher than the highest of said group of low output voltages, wherein each of said first through third output power supply voltages is provided as an operating voltage to at least one of said buffer circuits.