Compensation of threshold voltage in driving transistor of organic light emitting diode display device

摘要

The organic light emitting diode display device comprising a display panel a plurality of pixels arranged in a matrix form, each of the pixels comprising: a driving TFT including a gate electrode coupled to a first node, a source electrode coupled to a second node, and a drain electrode coupled to a high-potential voltage line; an organic light emitting diode including an anode coupled to the second node and a cathode coupled to a low-potential voltage line; a first TFT supplying a data voltage to the first node in response to a scan signal; a initialization control circuit initializing the first node to a first reference voltage and the second node or the third node to a second reference voltage in response to a initialization signal and an emission signal; and capacitors.

主权项

1. An organic light emitting diode display device comprising a plurality of pixels arranged in a matrix form, each of the pixels comprising:
a driving thin film transistor (TFT) including a gate electrode coupled to a first node, a source electrode coupled to a second node, and a drain electrode coupled to a high-potential voltage line; an organic light emitting diode between the second node and a low-potential voltage line; a first TFT configured to connect a data line to the first node during a data voltage supply period of a frame period; an initialization control circuit coupled between the first node and a first reference voltage line supplying a first reference voltage, the initialization control circuit further connected to a second node, a third node and a second reference voltage line supplying a second reference voltage, the initialization control circuit configured to initialize the first node to the first reference voltage, during an initialization period of the frame period preceding the data voltage supply period, the initialization control circuit configured to initialize the second and third nodes to a second reference voltage during the initialization period, the initialization control circuit comprising:
a second TFT including a gate electrode coupled to an emission line, a source electrode coupled to the third node, and a drain electrode coupled to the second node,a third TFT including a gate electrode coupled to an initialization line for carrying an initialization signal to indicate the initialization period, a source electrode coupled to the first reference voltage line supplying the first reference voltage, and a drain electrode coupled to the first node, anda fourth TFT including a gate electrode coupled to the initialization line, a source electrode coupled to the second reference voltage line supplying the second reference voltage, and a drain electrode coupled to the third node, the third TFT and the fourth TFT receiving the initialization signal simultaneously; and a first capacitor coupled between the first node and the third node, the first capacitor configured to store a voltage difference between the first node and the third node during the initialization period, and change a voltage level of the first node based on a voltage level of the third node in a threshold voltage sensing period between the initialization period and the data voltage supply period.