Method of driving a liquid crystal display panel and liquid crystal display device employing the same

Patent metadata

Field	Value
Publication number	US-10847113-B2
Application number	US-201916263257-A
Country	US
Kind code	B2
Filing date	Jan 31, 2019
Priority date	Feb 6, 2018
Publication date	Nov 24, 2020
Grant date	Nov 24, 2020

Abstract

A method of driving a liquid crystal display panel is provided. The liquid crystal display panel includes: a liquid crystal display pixel including a liquid crystal structure including a pixel electrode, a liquid crystal layer, and a common electrode; a switching transistor connected between the pixel electrode of the liquid crystal structure and a data-line; and a storage capacitor connected to the pixel electrode of the liquid crystal structure. The method includes: calculating an accumulated driving time of the liquid crystal display panel by accumulating a driving time of the liquid crystal display panel; determining whether or not the accumulated driving time has reached a deterioration reference time; and when the accumulated driving time is determined to have reached the deterioration reference time, changing a gate-off voltage applied to a gate terminal of the switching transistor and a common voltage applied to the common electrode.

First claim

What is claimed is:

1. A method of driving a liquid crystal display panel, the liquid crystal display panel comprising: a liquid crystal display pixel comprising a liquid crystal structure comprising a pixel electrode, a liquid crystal layer, and a common electrode; a switching transistor connected between the pixel electrode of the liquid crystal structure and a data-line; and a storage capacitor connected to the pixel electrode of the liquid crystal structure, the method comprising:
reading an accumulated driving time of the liquid crystal display panel from memory;
accumulating the driving time of the liquid crystal display panel by adding to the accumulated driving time of the liquid crystal display panel in the memory;
determining whether or not the accumulated driving time has reached a deterioration reference time; and
when the accumulated driving time is determined to have reached the deterioration reference time, reducing a gate-off voltage applied to a gate terminal of the switching transistor and reducing a common voltage applied to the common electrode.

2. The method of claim 1 , wherein a gate-on voltage applied to the gate terminal of the switching transistor is not changed.

3. A method of driving a liquid crystal display panel, the liquid crystal display panel comprising: a liquid crystal display pixel comprising a liquid crystal structure comprising a pixel electrode, a liquid crystal layer, and a common electrode; a switching transistor connected between the pixel electrode of the liquid crystal structure and a data-line; and a storage capacitor connected to the pixel electrode of the liquid crystal structure, the method comprising:
reading an accumulated driving time of the liquid crystal display panel from memory;
accumulating the driving time of the liquid crystal display panel by adding to the accumulated driving time of the liquid crystal display panel in the memory;
determining whether or not the accumulated driving time has reached first through (k)-th deterioration reference times, wherein k is an integer greater than or equal to 2; and
when the accumulated driving time is determined to have sequentially reached the first through (k)-th deterioration reference times, sequentially reducing a gate-off voltage applied to a gate terminal of the switching transistor and sequentially reducing a common voltage applied to the common electrode.

4. The method of claim 3 , wherein a gate-on voltage applied to the gate terminal of the switching transistor is not changed.

5. The method of claim 4 , wherein the gate-off voltage is sequentially reduced as the accumulated driving time sequentially reaches the first through (k)-th deterioration reference times, and
wherein a voltage difference between the gate-on voltage and the gate-off voltage is sequentially increased as the gate-off voltage is sequentially reduced.

6. The method of claim 5 , wherein the gate-off voltage is sequentially reduced in the order of first through (k)-th gate-off voltages as the accumulated driving time sequentially reaches the first through (k)-th deterioration reference times, the first through (k)-th gate-off voltages being mapped to the first through (k)-th deterioration reference times, respectively.

7. The method of claim 5 , wherein the gate-off voltage is sequentially reduced by a reduction amount as the accumulated driving time sequentially reaches the first through (k)-th deterioration reference times.

8. The method of claim 7 , wherein the reduction amount is constant as the accumulated driving time sequentially reaches the first through (k)-th deterioration reference times.

9. The method of claim 7 , wherein the reduction amount differs as the accumulated driving time sequentially reaches the first through (k)-th deterioration reference times.

10. The method of claim 3 , wherein the common voltage is sequentially reduced in the order of first through (k)-th common voltages as the accumulated driving time sequentially reaches the first through (k)-th deterioration reference times, the first through (k)-th common voltages being mapped to the first through (k)-th deterioration reference times, respectively.

11. The method of claim 3 , wherein the common voltage is sequentially reduced by a reduction amount as the accumulated driving time sequentially reaches the first through (k)-th deterioration reference times.

12. The method of claim 11 , wherein the reduction amount is constant as the accumulated driving time sequentially reaches the first through (k)-th deterioration reference times.

13. The method of claim 11 , wherein the reduction amount differs as the accumulated driving time sequentially reaches the first through (k)-th deterioration reference times.

14. A liquid crystal display device comprising:
a liquid crystal display panel comprising:
a liquid crystal display pixel comprising a liquid crystal structure comprising a pixel electrode, a liquid crystal layer, and a common electrode;
a switching transistor connected between the pixel electrode of the liquid crystal structure and a data-line; and
a storage capacitor connected to the pixel electrode of the liquid crystal structure;

a backlight configured to provide light to the liquid crystal display panel;
a backlight driver configured to drive the backlight; and
a liquid crystal display panel driver configured to drive the liquid crystal display panel,
wherein the liquid crystal display panel driver is configured to calculate an accumulated driving time of the liquid crystal display panel by accumulating a lifetime driving time of the liquid crystal display panel, to store the accumulated driving time of the liquid crystal display panel into memory, and to reduce a gate-off voltage applied to a gate terminal of the switching transistor and a common voltage applied to the common electrode when the accumulated driving time reaches a deterioration reference time, and
wherein the liquid crystal display panel driver is configured to not change a gate-on voltage applied to the gate terminal of the switching transistor.

15. The liquid crystal display device of claim 14 , wherein the liquid crystal display panel driver comprises:
a scan driver configured to provide a scan signal corresponding to the gate-off voltage and the gate-on voltage to the liquid crystal display panel via scan-lines;
a data driver configured to provide a data signal corresponding to a pixel voltage to the liquid crystal display panel via data-lines;
a timing controller configured to control the scan driver and the data driver;
a power manager configured to provide source power to the scan driver, the data driver, and the timing controller; and
a voltage adjuster configured to reduce the common voltage and the gate-off voltage based on the accumulated driving time by interacting with the scan driver and the power manager.

16. A liquid crystal display device comprising:
a liquid crystal display panel comprising:
a liquid crystal display pixel comprising a liquid crystal structure comprising a pixel electrode, a liquid crystal layer, and a common electrode;
a switching transistor connected between the pixel electrode of the liquid crystal structure and a data-line; and
a storage capacitor connected to the pixel electrode of the liquid crystal structure;

a backlight configured to provide light to the liquid crystal display panel;
a backlight driver configured to drive the backlight; and
a liquid crystal display panel driver configured to drive the liquid crystal display panel,
wherein the liquid crystal display panel driver is configured to cal

Assignees

• Samsung Display Co Ltd

Inventors

• Kwon Sangan
• Lee Junpyo
• Kim Kyunho
• Kim Sungjin
• Shin Yong-Jin
• Lee Neung-Beom
• Lim Kyung-Hwa
• Jang Jinhyuk

Classifications

• G09G2320/043

  Preventing or counteracting the effects of ageing · CPC title

• G09G2300/0819

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

• G09G3/3696 Primary

  Generation of voltages supplied to electrode drivers · CPC title

• G09G3/3655 Primary

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

• G09G3/3648 Primary

  using an active matrix (G09G3/367 - G09G3/3696 take precedence) · CPC title