Display device and method of driving display device

Patent metadata

Field	Value
Publication number	US-9886910-B2
Application number	US-201615341029-A
Country	US
Kind code	B2
Filing date	Nov 2, 2016
Priority date	Nov 9, 2015
Publication date	Feb 6, 2018
Grant date	Feb 6, 2018

Abstract

A display device including a pixel, a drive transistor including a first and a second terminal and a gate, a first switching element controlling a connection between the second terminal and the gate, a storage capacitor of a second terminal connected to the gate, a second switching element controlling a connection between the storage capacitor and a first signal line, a third switching element arranged in parallel with the second switching element and controlling a connection between the storage capacitor and a second signal line, a fourth switching element controlling a connection between the drive transistor and a first power supply line, a light emitting element connected with the drive transistor and a second power supply line, a fifth switching element controlling a connection between the drive transistor and the light emitting element, a sixth switching element controlling a connection between the drive transistor and a third power supply line.

First claim

What is claimed is:

1. A display device comprising:
a pixel including a drive transistor, a first switching element, a storage capacitor, a second switching element, a third switching element, a fourth switching element, a light emitting element, a fifth switching element and a sixth switching element;
the drive transistor including a first terminal, a second terminal, and a gate which controlling a current flowing between the first terminal and the second terminals;
the first switching element controlling a connection between the second terminal and the gate of the drive transistor;
the storage capacitor including a first terminal and a second terminal, the second terminal of the storage capacitor connected to the gate of the driving transistor;
the second switching element controlling a connection between the first terminal of the storage capacitor and a first signal line supplied with a data signal;
the third switching element arranged in parallel with the second switching element and controlling a connection between the first terminal of the storage capacitor and a second signal line supplied with a reference signal;
the fourth switching element controlling a connection between the first terminal of the drive transistor and a first power supply line supplied with a first voltage;
the light emitting element including a first terminal and a second terminal, the first terminal of the light emitting element connected with the second terminal of the drive transistor and the second terminal of the light emitting element connected with a second power supply line supplied with a second voltage lower than the first voltage;
the fifth switching element controlling a connection between the second terminal of the drive transistor and the first terminal of the light emitting element; and
the sixth switching element controlling a connection between the first terminal of the drive transistor and a third power supply line supplied with a third voltage lower than the first voltage and higher than the second voltage.

2. The display device according to claim 1 , farther comprising:
a seventh switching element, the seventh switching element controlling a connection between the first terminal of the drive transistor and a first power supply line, and the sixth switching element and the seventh switching element is operated exclusively.

3. The display device according to claim 2 , wherein the first power supply line is arranged in a column direction and the third power supply line is arranged in a row direction.

4. The display device according to claim 2 , further comprising:
a reset time period during which the first switching element and the fifth switching element are turned ON, the fourth switching element is turned OFF, a reference voltage is applied to the storage capacitor from the second signal line via the third switching element, and a third voltage is applied to the first terminal of the drive transistor from the third power supply line;
a signal programming and offset cancel time period during which the first switching element and the fourth switching element are turned ON, the fifth switching element is turned OFF, a voltage based on a data signal from the first signal line is applied to the first terminal of the storage capacitor via the second switching element, and the first voltage is applied from the first power supply line and the third power supply line to the first terminal of the drive transistor; and
a light emitting time period during which the first switching element is turned OFF, the fourth switching element and the fifth switching element are turned ON, a reference voltage is applied to the first terminal of the storage capacitor via the third switching element, and the light emitting element emits light by a current flowing from the first power supply line via the drive transistor.

5. The display device according to claim 2 , wherein the first switching element, the second switching element, the fifth switching element and the sixth switching element are arranged in a first conductivity type transistor, and the third switching element, the fourth switching element and the seventh switching element are arranged in a second conductivity type transistor, the second conductivity type is opposite to the first conduction type.

6. The display device according to claim 1 , further comprising:
a reset time period during which the first switching element and the fifth switching element are turned ON, the fourth switching element is turned OFF, a reference voltage is applied to the storage capacitor from the second signal line via the third switching element, and a third voltage is applied to the first terminal of the drive transistor from the third power supply line;
a signal programming and offset cancel time period during which the first switching element and the fourth switching element are turned ON, the fifth switching element is turned OFF, a voltage based on a data signal from the first signal line is applied to the first terminal of the storage capacitor via the second switching element, and the first voltage is applied from the first power supply line to the first terminal of the drive transistor; and
a light emitting time period during which the first switching element is turned OFF, the fourth switching element and the fifth switching element are turned ON, a reference voltage is applied to the first terminal of the storage capacitor via the third switching element, and the light emitting element emits light by a current flowing from the first power supply line via the drive transistor.

7. The display device according to claim 6 , wherein the first switching element is a transistor, and a control signal including a first voltage level turning the first switching element ON, a second voltage level turning the first switching element OFF and a third voltage level higher than the second voltage level is applied to a gate of the first switching element as transistor, and in at least the light emitting period, the first switching element is maintained in an OFF state by a control signal at the third voltage level.

8. The display device according to claim 1 , wherein a plurality of the pixels is arranged and the fourth switching element is shared among adjacent pixels.

9. The display device according to claim 1 , wherein a plurality of the pixels is arranged and the second switching element and the third switching element are shared among adjacent pixels.

10. The display device according to claim 1 , wherein the first switching element, the second switching element and the fifth switching element are arranged in a first conductivity type transistor, and the third switching element and the fourth switching element are arranged in a second conductivity type transistor, the second conductivity type is opposite to the first conductivity type.

11. A method for driving a display device, the display device comprising;
a pixel including a drive transistor, a first switching element, a storage capacitor, a second switching element, a third switching element, a fourth switching element, a light emitting element, a fifth switching element and a sixth switching element; the drive transistor including a first terminal, a second terminal and a gate which controlling a current flowing between the first terminal and the second terminals; the first switching element controlling a connection between the second terminal and the gate of the drive transistor; the storage capacitor including a first terminal and a second terminal, the second terminal of the storage capacitor connected to the gate of the driving transistor; the second switching element controlling a connection between the first terminal of t

Assignees

• Japan Display Inc

Inventors

• Wu Ilin
• PENG Duzen

Classifications

• G09G2300/0861

  with additional control of the display period without amending the charge stored in a pixel memory, e.g. by means of additional select electrodes · CPC title

• G09G2300/0842

  forming a memory circuit, e.g. a dynamic memory with one capacitor · CPC title

• G09G2310/08

  Details of timing specific for flat panels, other than clock recovery · CPC title

• G09G2320/045

  Compensation of drifts in the characteristics of light emitting or modulating elements · CPC title

• G09G2300/043

  Compensation electrodes or other additional electrodes in matrix displays related to distortions or compensation signals, e.g. for modifying TFT threshold voltage in column driver · CPC title