Display device

Patent metadata

Field	Value
Publication number	US-11580906-B2
Application number	US-202017101366-A
Country	US
Kind code	B2
Filing date	Nov 23, 2020
Priority date	Mar 3, 2020
Publication date	Feb 14, 2023
Grant date	Feb 14, 2023

Abstract

A display device includes pixels, and each pixel is connected between a first electrode or a second electrode of a driving transistor and a bias line, includes a bias transistor configured to transfer a bias voltage applied from the bias line to the first electrode or the second electrode of the driving transistor during a bias period. Bias voltages applied to the pixels emitting light of different colors are different from each other.

First claim

What is claimed is:

1. A display device including a plurality of pixels, comprising:
each of the plurality of pixels, including:
a light-emitting diode;
a driving transistor including a gate electrode, a first electrode connected to a node, and a second electrode connected to the light-emitting diode, the driving transistor being configured to transfer a driving current to the light-emitting diode;
a switching transistor connected between a data line and the node and configured to transfer a data signal applied to the data line to the node during a data write period;
a compensation transistor connected between the gate electrode of the driving transistor and the second electrode of the driving transistor and configured to connect the gate electrode of the driving transistor to the second electrode of the driving transistor during a compensation period; and
a bias transistor connected between at least one of the first electrode and the second electrode of the driving transistor and a bias line and configured to transfer a bias voltage applied from the bias line to the at least one of the first electrode and the second electrode of the driving transistor during a bias period,
wherein a first bias voltage applied to a first pixel emitting light of a first color among the plurality of pixels is different from a second bias voltage applied to a second pixel emitting light of a second color among the plurality of pixels.

2. The display device of claim 1 ,
wherein the bias period precedes the data write period, and
wherein the compensation period follows the data write period.

3. The display device of claim 1 ,
wherein the bias period follows the data write period, and
wherein the compensation period follows the data write period.

4. The display device of claim 1 ,
wherein each of the plurality of pixels further includes:
a first initialization transistor connected between the gate electrode of the driving transistor and a first initialization voltage line and configured to transfer a first initialization voltage to the gate electrode of the driving transistor during an initialization period, the first initialization voltage being applied from the first initialization voltage line; and
a second initialization transistor connected between the light-emitting diode and a second initialization voltage line and configured to transfer a second initialization voltage to a first electrode of the light-emitting diode during the bias period, the second initialization voltage being applied from the second initialization voltage line.

5. The display device of claim 1 ,
wherein each of the plurality of pixels further includes a capacitor connected between the gate electrode of the driving transistor and a driving voltage line.

6. The display device of claim 1 ,
wherein a third bias voltage applied to a third pixel emitting light of a third color among the plurality of pixels is the same as the first bias voltage applied to the first pixel or the second bias voltage applied to the second pixel.

7. The display device of claim 1 ,
wherein the bias transistor includes a first bias transistor and a second bias transistor, the first bias transistor being connected between the first electrode of the driving transistor and the bias line, and the second bias transistor being connected between the second electrode of the driving transistor and the bias line, and
wherein the first bias transistor and the second bias transistor are simultaneously turned on.

8. A display device including a plurality of pixels, comprising:
each of the plurality of pixels, including:
a light-emitting diode;
a driving transistor including a gate electrode, a first electrode connected to a node, and a second electrode connected to the light-emitting diode, the driving transistor being configured to transfer a driving current to the light-emitting diode;
a switching transistor connected between a data line and the node and configured to transfer a data signal applied to the data line to the node during a data write period;
a compensation transistor connected between the gate electrode of the driving transistor and the second electrode of the driving transistor and configured to connect the gate electrode of the driving transistor to the second electrode of the driving transistor during a compensation period; and
a bias transistor connected between at least one of the first electrode and the second electrode of the driving transistor and a bias line and configured to transfer a bias voltage applied from the bias line to the at least one of the first electrode and the second electrode of the driving transistor during a bias period,
wherein the bias transistor is turned on by an on-voltage of a bias control signal applied to a gate electrode of the bias transistor, and
wherein a first on-voltage application time of a first bias control signal applied to a first pixel emitting light of a first color among the plurality of pixels is different from a second on-voltage application time of a second bias control signal applied to a second pixel emitting light of a second color among the plurality of pixels.

9. The display device of claim 8 ,
wherein the bias period precedes the data write period, and
wherein the compensation period follows the data write period.

10. The display device of claim 8 ,
wherein the bias period follows the data write period, and
wherein the compensation period follows the data write period.

11. The display device of claim 8 ,
wherein the first on-voltage application time of the bias control signal applied to the first pixel is twice the second on-voltage application time of the bias control signal applied to the second pixel.

12. The display device of claim 8 ,
wherein each of the plurality of pixels further includes:
a first initialization transistor connected between the gate electrode of the driving transistor and a first initialization voltage line and configured to transfer a first initialization voltage to the gate electrode of the driving transistor during an initialization period, the first initialization voltage being applied from the first initialization voltage line; and
a second initialization transistor connected between the light-emitting diode and a second initialization voltage line and configured to transfer a second initialization voltage to a first electrode of the light-emitting diode during the bias period, the second initialization voltage being applied from the second initialization voltage line.

13. The display device of claim 8 ,
wherein each of the plurality of pixels further includes a capacitor connected between the gate electrode of the driving transistor and a driving voltage line.

14. The display device of claim 8 ,
wherein a third on-voltage application time of a third bias control signal applied to a third pixel emitting light of a third color among the plurality of pixels is the same as the first on-voltage application time of the first bias control signal applied to the first pixel or the second on-voltage application time of the second bias control signal applied to the second pixel.

15. A display device including a plurality of pixels,
wherein each of the plurality of pixels, including:
a light-emitting diode;
a driving transistor including a gate electrode, a first electrode connected to a node, and a second electrode connected to the light-emitting diode, the driving transistor being configured to transfer a driving current to the light-emitting diode;
a switching transistor connected between a data line and the node and configured to transfer a data sig

Assignees

• Samsung Display Co Ltd

Inventors

• Wang Seongmin
• Yang Yongho
• Kong Jihye
• Lee Jeongsoo

Classifications

• G09G2300/0819

  used for counteracting undesired variations, e.g. feedback or autozeroing · CPC title

• G09G2300/0469

  Details of the physics of pixel operation · CPC title

• G09G3/3233 Primary

  with pixel circuitry controlling the current through the light-emitting element · CPC title

• G09G2310/0256

  with the purpose of reversing the voltage across a light emitting or modulating element within a pixel · CPC title

• G09G3/2003

  Display of colours (specific for liquid crystal displays G09G3/3607) · CPC title