METHOD AND SYSTEM FOR PROGRAMMING AND DRIVING ACTIVE MATRIX LIGHT EMITTING DEVICE PIXEL HAVING A CONTROLLABLE SUPPLY VOLTAGE

摘要

Method and system for programming and driving active matrix light emitting device pixel is provided. The pixel is a voltage programmed pixel circuit, and has a light emitting device, a driving transistor and a storage capacitor. The pixel has a programming cycle having a plurality of operating cycles, and a driving cycle. During the programming cycle, the voltage of the connection between the OLED and the driving transistor is controlled so that the desired gate-source voltage of a driving transistor is stored in a storage capacitor.

主权项

1. A method of programming and driving a display system, the display system includes:
a display array having a plurality of pixel circuits arranged in row and column, each pixel circuit having:
a light emitting device having a first terminal and a second terminal, the first terminal of the lighting device being connected to a voltage supply electrode;a capacitor having a first terminal and a second terminal;a switch transistor having a gate terminal, a first terminal and a second terminal, the gate terminal of the switch transistor being connected to a select line, the first terminal of the switch transistor being connected to a signal line for transferring voltage data, the second terminal of the switch transistor being connected to the first terminal of the capacitor; anda driving transistor having a gate terminal, a first terminal and a second terminal, the gate terminal of the driving transistor being connected to the second terminal of the switch transistor and the first terminal of the capacitor at a first node (A), the first terminal of the driving transistor being connected to the second terminal of the light emitting device and the second terminal of the capacitor at a second node (B), the second terminal of the driving transistor being connected to a controllable voltage supply line; a driver for driving the select line, the controllable voltage supply line and the signal line to operate the display array; the method comprising the steps of:
at a programming cycle, at a first operating cycle, charging the second node at a first voltage defined by (VREF−VT) or (−VREF+VT), where VREF represents a reference voltage and VT represents a threshold voltage of the driving transistor;at a second operating cycle, charging the first node at a second voltage defined by (VREF+VP) or (−VREF+VP) so that the difference between the first and second voltages is stored in the storage capacitor, where VP represents a programming voltage; at a driving cycle, applying the voltage stored in the storage capacitor to the gate terminal of the driving transistor.