Display device, method for driving display device and method for minimizing afterimage of display device

Patent metadata

Field	Value
Publication number	US-10062346-B2
Application number	US-201514743650-A
Country	US
Kind code	B2
Filing date	Jun 18, 2015
Priority date	Dec 31, 2014
Publication date	Aug 28, 2018
Grant date	Aug 28, 2018

Abstract

A display device including: a liquid crystal panel assembly including pixels; a data driver applying a data voltage to lines which is connected to the pixels; and a common voltage generator providing voltage to the liquid crystal panel assembly, in which the voltage is an optimal voltage for a maximum grayscale at which a flicker is minimized while a maximum grayscale is applied to the pixels, the data driver applies the data voltage with the minimum grayscale to the data lines so that a negative data voltage with a minimum grayscale is higher than the common voltage by a first voltage level or more, and each of the pixels includes a first subpixel and a second subpixel, and when the data voltage is applied to the pixel, a pixel voltage of the first subpixel and a pixel voltage of the second subpixel are different.

First claim

What is claimed is:

1. A display device, comprising:
a liquid crystal panel assembly including a plurality of pixels;
a data driver applying a data voltage to a plurality of data lines which is connected to the plurality of pixels; and
a common voltage generator providing a common voltage to the liquid crystal panel assembly,
wherein the common voltage is an optimal common voltage for a maximum grayscale at which a flicker is minimized while a data voltage with a maximum grayscale is applied to the plurality of pixels,
the data driver applies the data voltage with the minimum grayscale to the plurality of data lines so that a negative data voltage with a minimum grayscale is higher than the common voltage by a first voltage level or more, and
each of the plurality of pixels includes a first subpixel and a second subpixel, and when the data voltage is applied to the pixel, a pixel voltage of the first subpixel and a pixel voltage of the second subpixel are different from each other.

2. The display device of claim 1 , wherein:
the data driver increases the data voltage with the minimum grayscale while a difference between the positive data voltage and the negative data voltage with the minimum grayscale is uniformly maintained.

3. The display device of claim 2 , wherein:
the first voltage level is a reference voltage at which ion impurities are suppressed from moving in a black pattern region where the data voltage with the minimum grayscale is applied.

4. The display device of claim 2 , wherein:
the first voltage level is 1 V.

5. The display device of claim 2 , wherein:
the data driver increases the data voltage with the minimum grayscale so that the negative data voltage with the minimum grayscale is higher than the common voltage by a second voltage level, and
the second voltage level is higher than the first voltage and is a maximum voltage at which a side contrast ratio for the minimum grayscale is not changed.

6. The display device of claim 2 , wherein:
the positive data voltage with the minimum grayscale is higher than the negative data voltage with the minimum grayscale, and
the data driver maximally sets a difference between the negative data voltage with the minimum grayscale and the common voltage within a range where the side contrast ratio for the minimum grayscale is not changed.

7. The display device of claim 1 , wherein:
the first subpixel includes
a first switching element connected to the data line; and
a first liquid crystal capacitor connected to the first switching element.

8. The display device of claim 7 , wherein:
the second subpixel includes:
a second switching element connected to the data line;
a second liquid crystal capacitor connected to the second switching element; and
a third switching element connected to the second liquid crystal capacitor and a divided reference voltage line.

9. A driving method of a display device including a common electrode and a pixel electrode, the method comprising:
applying a common voltage to the common electrode; and
applying a data voltage to the pixel electrode,
wherein the common voltage is an optimal common voltage for a maximum grayscale at which a flicker is minimized while a data voltage with a maximum grayscale is applied to the plurality of pixels, and
when the data voltage is a data voltage with a minimum grayscale, the data voltage with the minimum grayscale is increased and applied to be higher than the common voltage by a first voltage level or more.

10. The driving method of claim 9 , wherein:
the data voltage with the minimum grayscale includes a positive data voltage and a negative data voltage, and the data voltage with the minimum grayscale is increased while a difference between the positive data voltage and the negative data voltage with the minimum grayscale is uniformly maintained.

11. The driving method of claim 10 , wherein:
the first voltage level is a reference voltage at which ion impurities are suppressed from moving in a black pattern region where the data voltage with the minimum grayscale is applied.

12. The driving method of claim 10 , wherein:
the first voltage level is 1 V.

13. The driving method of claim 10 , wherein:
the data voltage with the minimum grayscale is increased so that the negative data voltage with the minimum grayscale is higher than the common voltage by a second voltage level, and
the second voltage level is higher than the first voltage level and is a maximum voltage at which a side contrast ratio for the minimum grayscale is not changed.

14. The driving method of claim 9 , wherein:
each of the plurality of pixels includes a first subpixel and a second subpixel, and when the data voltage is applied to the pixel, a pixel voltage of the first subpixel and a pixel voltage of the second subpixel are different from each other.

15. The driving method of claim 14 , wherein:
the first subpixel includes a first switching element connected to the data line and a first liquid crystal capacitor connected to the first switching element, and the first liquid crystal capacitor is charged by a difference between the data voltage and the common voltage.

16. The driving method of claim 15 , wherein:
the second subpixel includes a second switching element connected to the data line, a second liquid crystal capacitor connected to the second switching element, and a third switching element connected to the second liquid crystal capacitor and a divided reference voltage line, and the second liquid crystal capacitor is charged by decreasing the charging voltage of the difference between the data voltage and the common voltage by a difference between the charging voltage and the divided reference voltage of the divided voltage reference line.

Assignees

• Samsung Display Co Ltd
• Samsung Display Co Ltd

Inventors

• Park Joon-Hyung
• Kwon Sun Young
• Kim Min-Hee
• Bae Ji Hong
• Son Jong Ho
• Oh Keun Chan
• Lee Kyung Hee
• Jeong Kang Seob
• Tak Kyung Seon

Classifications

• G09G3/36 Primary

  using liquid crystals · CPC title

• G09G3/3655 Primary

  Details of drivers for counter electrodes, e.g. common electrodes for pixel capacitors or supplementary storage capacitors · CPC title

• G09G2300/0469

  Details of the physics of pixel operation · CPC title

• G09G2300/0447

  for multi-domain technique to improve the viewing angle in a liquid crystal display, such as multi-vertical alignment [MVA] · CPC title

• G09G2320/0257

  Reduction of after-image effects · CPC title