System and driving method for light emitting device display
A light emitting device display, its pixel circuit and its driving technique is provided. The pixel includes a light emitting device and a plurality of transistors. A bias current and programming voltage data are provided to the pixel circuit in accordance with a driving scheme so that the current through the driving transistor to the light emitting device is adjusted.
1. A pixel circuit comprising:
a light emitting device;
a storage capacitor;
a driving transistor for providing a pixel current to the light emitting device, the driving transistor having a gate terminal, a first terminal connected to the storage capacitor, and
a second terminal connected to the light emitting device;
a first switch transistor electrically connected between a bias line and the first terminal of the driving transistor; and
a second switch transistor electrically connected between a reference voltage line and the gate terminal of the driving transistor; and
an emission control transistor having a gate terminal connected to an emission control line, a first terminal connected to a voltage supply line different from the reference voltage line, and a second terminal connected to the first terminal of the driving transistor.
2. The pixel circuit according to claim 1 , wherein the first switch transistor and the second voltage switch transistor set the voltage across the gate and the first terminal of the driving transistor during a programming cycle.
3. The pixel circuit according to claim 2 , wherein the emission control transistor disconnects the driving transistor from the voltage supply line during the programming cycle.
4. The pixel circuit according to claim 1 , further comprising a third switch transistor that connects the storage capacitor to the gate of the driving transistor during a driving cycle in which the light emitting device emits light.
5. The pixel circuit according to claim 1 , further comprising a fourth switch transistor that connects the storage capacitor to a data voltage line during a programming cycle.