Liquid crystal display device, power supply circuit, and method for controlling liquid crystal display device

A power supply circuit, comprising:

• an operational amplifier;
• an output transistor section including output transistors in a plurality of stages connected to an output of the operational amplifier;
• an I-V converter circuit including a transistor forming a current mirror together with an associated one of the output transistors;
• and
• a switching circuit for controlling an ON/OFF state of an associated one of the output transistors based on an output signal from the I-V converter circuit, the switching circuit being connected to the I-V converter circuit and the output transistor section.

A liquid crystal display device, comprising:

• a display section for displaying an image;
• a power supply circuit for supplying power for controlling the image on the display section, the power supply circuit including an operational amplifier;
• a comparator for comparing an output from the operational amplifier with a standard value;
• and
• a switching section for controlling an ON/OFF state of the operational amplifier based on an output signal from the comparator.

A liquid crystal display device, comprising:

• a display section for displaying an image;
• a power supply circuit including an operational amplifier for supplying power for controlling the image on the display section, and
• a controller circuit for generating a signal for controlling the image on the display section,
• wherein the operational amplifier is stopped during a blanking period, and the operational amplifier is stopped based on the signal from the controller circuit during the blanking period.

A method for controlling a liquid crystal display device including a display section, a driver circuit for supplying a voltage to the display section, a controller circuit for supplying, to the driver circuit, a signal for controlling the voltage, and a power supply circuit for supplying power to the driver circuit, the method comprising:

• a first step of calculating the amount of change in the signal from the controller circuit;
• and
• a second step of supplying power from the power supply circuit to the driver circuit based on the amount of change in the signal,
• wherein in the second step, the amount of a current supplied to the driver circuit is adjusted in accordance with the amount of change in the signal.