Abstract: A pixel structure for an active matrix OLED. A first switching transistor has a control terminal coupled to a first scan line, and a first terminal coupled to a data line. A first P-type transistor has a drain and a gate coupled to each other, and a source coupled to a voltage source. The drain is also coupled to a second terminal of the first switching transistor. A second P-type transistor has a source coupled to the voltage source, and a second switching transistor has two terminals coupled between gates of the first and second P-type transistors, and a control terminal coupled to a second scan line. A storage capacitor is coupled between the voltage source and the gate of the second P-type transistor. An OLED has an anode coupled to the drain of the second P-type transistor and a cathode coupled to ground.

Abstract: The main differences between the present invention the conventional pixel circuit for active matrix of current driving device is the usage of the auxiliary transistor(s). In the invention, at least one auxiliary transistor is used to separate both the transistor, which is directly electrically coupled to the current driving device, and the plate, which is not directly electrically coupled with a constant voltage source, of the capacitor from the other transistors of the pixel circuit. Hence, all circuit and voltage, which are induced by the switching process of these transistors, are blocked or compensate by the auxiliary transistor(s), and the stored voltage of the capacitor would be unaffected.

Abstract: An active matrix LED pixel driving circuit. The circuit includes a capacitor, a light emitting diode, and a first and second transistor. The capacitor is connected between a gate and source of the first transistor, and the second transistor has a source connected to a drain of the first transistor and a gate connected to receive a first voltage by which the first and second transistor operates in a saturation region, and a current switch controlled by a scan signal, wherein a first current corresponding to a data signal flows through the first and second transistor to generate a second voltage stored on the capacitor when the current switch is closed, and a second current through the first and second transistor is generated by the second voltage stored on the capacitor to turn on the light emitting diode when the current switch is opened.

Abstract: The present invention is related to a unit gain buffer of the driver circuit to drive the data line in the filed of LCD data driver, further to be preferably applied to the new TFT-LCD processing of low temperature poly-silicon. This invention is using the plurality of PMOS transistor connection to result in the almost same value between the Vout and Vin. There is no using of the feedback connection in this invention, so the using of the compensation capacitor can be avoided, furthermore the data driver layout area of the LCD driver can be reduced. This invention can improve the defect of the larger layout area result from the prior art.

Abstract: Disclosed is a source follower with Vgs compensation, such that the output voltage precisely follows the input voltage by various arrangements of MOSFET's, switches, and capacitors. In addition, such a source follower that the output voltage precisely follows the input voltage can be implemented without adding too many components. The source follower disclosed in the present invention can be used in the driver circuit for a liquid crystal display (LCD).