Pixel circuit, driving method, display panel and display device

Patent metadata

Field	Value
Publication number	US-2016189606-A1
Application number	US-201514884442-A
Country	US
Kind code	A1
Filing date	Oct 15, 2015
Priority date	Dec 30, 2014
Publication date	Jun 30, 2016
Grant date	—

Abstract

The application provides a pixel circuit, a driving method, a display panel and a display device. The pixel circuit includes a first transistor, a second transistor, a third transistor, a fourth transistor, a fifth transistor, a sixth transistor, a driving transistor, a storage capacitor and a light emitting element, and by cooperative driving of the respective transistors and the storage capacitor, the driving current of the driving transistor can be independent of the gate-source voltage and the threshold voltage of the driving transistor.

First claim

1 . A pixel circuit comprising a first transistor, a second transistor, a third transistor, a fourth transistor, a fifth transistor, a sixth transistor, a driving transistor, a storage capacitor and a light emitting element, wherein
a magnitude of a driving current of the driving transistor is determined by a gate-source voltage of the driving transistor; the first transistor is controlled by a first driving signal and is configured to transmit a first power supply signal to a drain of the driving transistor; the second transistor is controlled by a first scanning signal and is configured to transmit the first power supply signal to a first plate of the storage capacitor and a gate of the driving transistor; the third transistor is controlled by a second scanning signal and is configured to transmit a data signal to a source of the driving transistor; the fourth transistor is controlled by a second driving signal and is configured to transmit a voltage of the source of the driving transistor to a second plate of the storage capacitor; the fifth transistor is controlled by the first scanning signal and is configured to transmit a first reference voltage to the second plate of the storage capacitor; the sixth transistor is controlled by the second scanning signal and is configured to transmit the driving current from the driving transistor to an anode of the light emitting element; and a cathode of the light emitting element is connected to a second power supply signal, and the light emitting element is configured to emit light in response to the driving current.

2 . The pixel circuit according to claim 1 , wherein
a gate of the first transistor receives the first driving signal, a first electrode of the first transistor receives the first power supply signal, and a second electrode of the first transistor is electrically connected to a fourth node; a gate of the second transistor receives the first scanning signal, a first electrode of the second transistor is electrically connected to a first node, and a second electrode of the second transistor is electrically connected to the fourth node; the gate of the driving transistor is electrically connected to the first node, the drain of the driving transistor is electrically connected to the fourth node, and the source of the driving transistor is electrically connected to a third node; a gate of the third transistor receives the second scanning signal, a first electrode of the third transistor receives the data signal, and a second electrode of the third transistor is electrically connected to the third node; a gate of the fourth transistor receives the second driving signal, a first electrode of the fourth transistor is electrically connected to a second node, and a second electrode of the fourth transistor is electrically connected to the third node; a gate of the fifth transistor receives the first scanning signal, a first electrode of the fifth transistor is electrically connected to the second node, and a second electrode of the fifth transistor receives the first reference voltage; a gate of the sixth transistor receives the second driving signal, a first electrode of the sixth transistor is electrically connected to the third node, a second electrode of the sixth transistor is electrically connected to the anode of the light emitting element, and the cathode of the light emitting element receives the second power supply signal; and the first plate of the storage capacitor is electrically connected to the first node, and the second plate of the storage capacitor is electrically connected to the second node.

3 . The pixel circuit according to claim 1 , wherein the driving transistor is an N-type transistor.

4 . The pixel circuit according to claim 3 , wherein all of the first transistor, the second transistor, the third transistor, the fourth transistor, the fifth transistor and the sixth transistor are N-type transistors;

5 . The pixel circuit according to claim 3 , wherein the first transistor, the second transistor, the third transistor, the fourth transistor, the fifth transistor and the sixth transistor are P-type transistors.

6 . The pixel circuit according to claim 1 , wherein the light emitting element is an organic light emitting diode.

7 . The pixel circuit according to claim 1 , wherein a potential of the first power supply signal is higher than potential of the first reference voltage, and a potential of the first reference voltage is higher than potential of the second power supply signal.

8 . The pixel circuit according to claim 2 , wherein a potential of the first power supply signal is higher than a potential of the first reference voltage, and a potential of the first reference voltage is higher than a potential of the second power supply signal.

9 . The pixel circuit according to claim 3 , wherein a potential of the first power supply signal is higher than a potential of the first reference voltage, and a potential of the first reference voltage is higher than a potential of the second power supply signal.

10 . The pixel circuit according to claim 4 , wherein a potential of the first power supply signal is higher than a potential of the first reference voltage, and a potential of the first reference voltage is higher than a potential of the second power supply signal.

11 . The pixel circuit according to claim 5 , wherein a potential of the first power supply signal is higher than a potential of the first reference voltage, and a potential of the first reference voltage is higher than a potential of the second power supply signal.

12 . A driving method for driving a pixel circuit, wherein the pixel circuit comprises a first transistor, a second transistor, a third transistor, a fourth transistor, a fifth transistor, a sixth transistor, a driving transistor, a storage capacitor and a light emitting element, wherein
a magnitude of a driving current of the driving transistor is determined by a gate-source voltage of the driving transistor; the first transistor is controlled by a first driving signal and is configured to transmit a first power supply signal to a drain of the driving transistor; the second transistor is controlled by a first scanning signal and is configured to transmit the first power supply signal to a first plate of the storage capacitor and a gate of the driving transistor; the third transistor is controlled by a second scanning signal and is configured to transmit a data signal to a source of the driving transistor; the fourth transistor is controlled by a second driving signal and is configured to transmit a voltage of the source of the driving transistor to a second plate of the storage capacitor; the fifth transistor is controlled by the first scanning signal and is configured to transmit a first reference voltage to the second plate of the storage capacitor; the sixth transistor is controlled by the second scanning signal and is configured to transmit the driving current from the driving transistor to an anode of the light emitting element; and a cathode of the light emitting element is connected to a second power supply signal, and the light emitting element is configured to emit light in response to the driving current, and wherein the driving method comprises a reset stage, a threshold compensation stage and a light emitting stage. in the reset stage, transmitting the first power supply signal to the gate and the drain of the driving transistor; in the threshold compensation stage, transmitting the data signal to the first plate of the storage capacitor, and controlling the gate-source voltage of the driving transistor to remain constant, by the storage ca

Assignees

• Shanghai Tianma Am Oled Co Ltd
• Tianma Micro Electronics Co Ltd

Inventors

• Chen Dan
• Qian Dong
• Gu Hanyu

Classifications

• G09G2320/0233

  Improving the luminance or brightness uniformity across the screen · CPC title

• G09G3/2092

  Details of a display terminals using a flat panel, the details relating to the control arrangement of the display terminal and to the interfaces thereto (suitable for both CRT and flat panel G09G5/003; specific for a CRT G09G1/165) · CPC title

• G09G2330/028

  Generation of voltages supplied to electrode drivers in a matrix display other than LCD · CPC title

• G09G3/3225 Primary

  using an active matrix · CPC title

• G09G3/3659 Primary

  the addressing of the pixel involving the control of two or more scan electrodes or two or more data electrodes, e.g. pixel voltage dependant on signal of two data electrodes · CPC title