US Patent 7253815 OLED display and pixel structure thereof

An active matrix organic light-emitting diode (OLED) display and pixel structure thereof. The pixel structure comprises a first transistor, a storage capacitor, a second transistor, and an OLED. The first transistor has a gate terminal coupled to a scan signal and a drain terminal coupled to a data signal. The storage capacitor has two terminals coupled to a source terminal of the first transistor and a reference node with a second voltage. The second transistor has a gate terminal coupled to the source terminal of the first transistor and a source terminal coupled to the reference node. The OLED has a cathode coupled to a drain terminal of the second transistor and an anode coupled to a first voltage, higher than the second voltage. The second transistor is an amorphous silicon thin film transistor (a-Si TFT), and an equivalent channel width/length (W/L) ratio of the second transistor exceeds 10.