Patent ID: 8035593

Claim:
A display device comprising: a display panel having a plurality of video lines; and a drain driver receiving n-bit display data, and connected to the plurality of video lines; wherein the drain driver comprises: a gray-scale voltage generating circuit which generates M (M<2 n ) pieces of gray-scale voltages; a decoder circuit which selects two gray-scale voltages from the M pieces of gray-scale voltages based on upper-order bits of the n-bit display data; an operational amplifier comprising k(k≧3) pieces of non-inverting input terminals and one inverting input terminal connected to an output terminal of the operational amplifier; and a switching circuit which selects the two gray-scale voltages of the decoder circuit, and applies the two gray-scale voltages to the k pieces of non-inverting input terminals of the operational amplifier based on lower-order m (n>m≧2) bits of the n-bit display data; wherein the operational amplifier comprises a differential amplifying circuit which constitutes an input stage; and wherein the differential amplifying circuit which constitutes the input stage comprises: at least one inverting-side transistor comprising a control terminal thereof connected to the inverting input terminal; k pieces of non-inverting-side transistors constitute a differential pair with the at least one inverting-side transistor and comprise respective control terminals thereof connected to the respective non-inverting input terminals; and a weighting of an electrode width of control electrodes is applied to the k pieces of non-inverting-side transistors and at least one inverting-side transistor.