Patent ID: 6963323

Claim:
A power supply circuit, comprising: a voltage output circuit for generating a drive power supply voltage for a driver circuit for use in a display device, said voltage output circuit outputting said drive power supply voltage while changing a value thereof in response to an inputted control signal; a reference voltage generating circuit for generating a first reference voltage, input to the driver circuit, for use in generating a gray-scale voltage in said driver circuit; and a comparison circuit for performing a comparison of the drive power supply voltage and the first reference voltage to output said control signal in response to a result of the comparison, said comparison circuit including a comparison unit having the drive power supply voltage as a first input, having the first reference voltage as a second input, and delivering an output according to a difference between said first input and said second input, a reference voltage generating unit for generating a second reference voltage, and a difference amplifying unit for outputting said control signal based on a difference voltage between (1) the output of the comparison unit and (2) the second reference voltage, wherein the reference voltage generating unit generates said second reference voltage independently of said drive power supply voltage and said first reference voltage, and feedback control is performed to maintain a specified relation between said drive power supply voltage and said first reference voltage.