Tft pixel threshold voltage compensation circuit with short data programming time

Abstract

A pixel circuit for a display device is operable in a compensation phase, a data programming phase, and an emission phase, whereby the one horizontal time is minimized while maintaining accurate compensation of the threshold voltage of the drive transistor, and noise applied to the gate of drive transistor during the emission phase is substantially eliminated. The pixel circuit includes a drive transistor configured to control an amount of current from a power supply to a light-emitting device during the emission phase depending upon a voltage input applied to a gate of the drive transistor, and a threshold voltage of the drive transistor is compensated during the compensation phase. The pixel circuit further includes two transistors, one of which is connected between a data voltage input line and the other transistor, and the other transistor further is connected to the gate of the drive transistor, such that when the two transistors are in an on state during the data programming phase, the data voltage is applied to the gate of the drive transistor. The pixel circuit further may include another transistor that is connected between the power supply and a node Nbetween the two transistors, such that during the emission phase, the power supply is applied to the node Nto shield the drive transistor from noise from the data voltage input line.