Source driver circuit, and display device
A source driver circuit is provided that supplies, to each of pixels arranged in a matrix, an electrical signal corresponding to a pixel signal. The source driver circuit includes a reference voltage generating unit, which includes a plurality of resistors connected in series, and a resistor, for gradation voltage generation that divides an input voltage into voltages of magnitudes. The source driver circuit also includes a gradation voltage generating circuit, which is connected between the plurality of resistors and is also connected between the plurality of resistors and the resistor for gradation voltage generation, that includes an offset-canceling amplifier. The offset-canceling amplifier alternates between an offset extraction state, in which an offset voltage of the offset-canceling amplifier is extracted, and a buffer output state, in which the offset voltage is added to the pixel signal and outputted.
1. A source driver circuit that supplies, to each of pixels arranged in a matrix, an electrical signal corresponding to a pixel signal, the source driver circuit comprising:
a reference voltage generator, which includes a plurality of resistors connected in series;
a resistor for gradation voltage generation which divides an input voltage into voltages of magnitudes; and
a gradation voltage generating circuit, which is connected between the plurality of resistors and is also connected between the plurality of resistors and the resistor for gradation voltage generation, that includes an offset-canceling amplifier,
wherein the offset-canceling amplifier includes an amplifier, an offset capacitor, and a switch in series with an output of the amplifier, and
wherein the offset-canceling amplifier alternates between an offset extraction state, in which the switch is open and an offset voltage of the offset-canceling amplifier is extracted, and a buffer output state, in which the switch is closed and the offset voltage is added to the pixel signal and outputted.
2. The source driver circuit according to claim 1 ,
wherein in the offset extraction state, an electrical charge corresponding to the offset voltage of the amplifier is accumulated in the offset capacitor, and in the buffer output state, a voltage corresponding to the electrical charge accumulated in the offset capacitor is added to the pixel signal and outputted.
3. The source driver circuit according to claim 1 ,
wherein the pixels each include a light-emitting element, and
the light-emitting element is an organic electroluminescent (EL) element.
4. The source driver circuit according to claim 1 ,
wherein the offset-canceling amplifier enters the offset extraction state in a blanking period after an end of a video data period in which video data is displayed on a display screen, and enters the buffer output state after the offset voltage is accumulated as the electrical charge in the offset capacitor in the blanking period.
5. A display device, comprising:
the source driver circuit according to claim 1 .