Organic light emitting display, device for sensing threshold voltage of driving TFT in organic light emitting display, and method for sensing threshold voltage of driving TFT in organic light emitting display

摘要

A device for sensing a threshold voltage of a driving TFT in an organic light emitting display includes a data drive circuit and a timing controller. The data drive circuit applies a data voltage to a gate node of the driving TFT during a first programming period, determines a source node voltage of the driving TFT as a first sensing voltage during a first sensing period in which a gate-source voltage is constant and higher than the threshold voltage, applies another data voltage to the gate node during a second programming period, and determines the source node voltage as a second sensing voltage during a second sensing period in which the gate-source voltage is constant and higher than the threshold voltage. The timing controller calculates a ratio between the first and second sensing voltages, and obtains a change in the threshold voltage using a change in the ratio.