Display apparatus with reduced flash noise, and a method of driving the display apparatus

Patent metadata

Field	Value
Publication number	US-10304406-B2
Application number	US-201615380322-A
Country	US
Kind code	B2
Filing date	Dec 15, 2016
Priority date	Dec 16, 2015
Publication date	May 28, 2019
Grant date	May 28, 2019

Abstract

A display apparatus includes a display panel including a switching element connected to a data line and a gate line, a pixel electrode connected to the switching element, a common electrode facing the pixel electrode and a liquid crystal layer disposed between the pixel electrode and the common electrode. The display apparatus further includes a data driving circuit configured to convert image data to a data voltage. The display apparatus further includes a driving voltage generator configured to generate a common voltage, in response to a voltage control signal from a timing controller, to the common electrode and the data driving circuit, which is configured to output the common voltage to the pixel electrode during an initial setting period when power is turned on to the display apparatus.

First claim

What is claimed is:

1. A display apparatus, comprising:
a display panel comprising a switching element connected to a data line and a gate line, a pixel electrode connected to the switching element, a common electrode facing the pixel electrode and a liquid crystal layer disposed between the pixel electrode and the common electrode, the liquid crystal layer driven by a difference in voltages between a voltage applied to the pixel electrode and a voltage applied to the common electrode;
a data driving circuit configured to convert image data to a data voltage;
a driving voltage generator configured to generate a common voltage applied to the common electrode and an analog source voltage applied to the data driving circuit;
a data switching circuit configured to output the common voltage to the data line during an initial setting period when power is turned on to the display apparatus; and
a gate driver configured to generate a plurality of gate signals, and sequentially output the plurality of gate signals to a plurality of gate lines during the initial setting period.

2. The display apparatus of claim 1 , wherein the common voltage is applied to the pixel electrode and the common electrode during the initial setting period.

3. The display apparatus of claim 2 , wherein the common voltage is higher than a ground voltage and greater than or less than half of the analog source voltage.

4. The display apparatus of claim 1 , further comprising a gate driver configured to output a gate signal to the gate line.

5. The display apparatus of claim 1 , wherein the data switching circuit is configured to output the data voltage to the data line during a normal driving period after the initial setting period.

6. The display apparatus of claim 1 , wherein the liquid crystal layer is driven in a normally black mode.

7. The display apparatus of claim 1 , wherein the display panel comprises a first base substrate, a second base substrate facing the first base substrate, and the common electrode and the pixel electrode are disposed on a same base substrate.

8. The display apparatus of claim 1 , wherein either the common electrode or the pixel electrode comprises a plurality of lines.

9. A display apparatus, comprising:
a display panel comprising a switching element connected to a data line and a gate line, a pixel electrode connected to the switching element, a common electrode facing the pixel electrode and a liquid crystal layer disposed between the pixel electrode and the common electrode, the liquid crystal layer driven by a difference in voltages between a voltage applied to the pixel electrode and a voltage applied to the common electrode;
a data driving circuit configured to convert image data to a data voltage;
a driving voltage generator configured to generate a common voltage applied to the common electrode and an analog source voltage applied to the data driving circuit;
a data switching circuit configured to output an initial data voltage to the data line during an initial setting period when a power is turned on to the display apparatus, wherein the initial data voltage is either the common voltage, a half voltage of the analog source voltage or a ground voltage; and
a gate driver configured to sequentially output a plurality of gate signals to a plurality of gate lines during the initial setting period.

10. The display apparatus of claim 9 , wherein the driving voltage generator is configured to provide the data switching circuit with either the half voltage of the analog source voltage or the common voltage.

11. The display apparatus of claim 9 , wherein the data switching circuit is configured to output the data voltage to the data line during a normal driving period after the initial setting period.

12. The display apparatus of claim 9 , wherein the liquid crystal layer is driven in a normally black mode.

13. The display apparatus of claim 9 , wherein either the common electrode or the pixel electrode comprises a plurality of lines.

14. A method of driving a display apparatus which comprises a switching element connected to a data line and a gate line, a pixel electrode connected to the switching element, a common electrode facing the pixel electrode and a liquid crystal layer driven by a difference in voltages between a first voltage applied to the pixel electrode and a second voltage applied to the common electrode, the method comprising:
generating a common voltage applied to the common electrode;
outputting the common voltage to the data line during an initial setting period when a power is turned on to the display apparatus;
outputting a data voltage corresponding to an image data to the data line during a normal driving period after the initial setting period; and
sequentially outputting a plurality of gate signals to a plurality of gate lines during the initial setting period.

15. The method of claim 14 , wherein the common voltage is applied to the pixel electrode and the common electrode during the initial setting period.

16. The method of claim 15 , wherein the common voltage is higher than a ground voltage and greater than or less than half of an analog source voltage.

17. The method of claim 14 , further comprising:
applying the first voltage to the pixel electrode and the second voltage to the common electrode, wherein when the difference in voltage between the first voltage applied to the pixel electrode and the second voltage applied to the common electrode increases, a light transmissivity of the liquid crystal layer increases, and
when the difference in voltage between the first voltage applied to the pixel electrode and the second voltage applied to the common electrode decreases, the light transmissivity of the liquid crystal layer decreases.

18. The method of claim 14 , wherein the liquid crystal layer is driven by a horizontal electric field generated between the common electrode and the pixel electrode.

19. The method of claim 14 , wherein either the common electrode or the pixel electrode comprises a plurality of lines.

Assignees

• Samsung Display Co Ltd

Inventors

• Jin Jeong-Oh
• Kwon Hyeok-Tae
• Kim Dongkeon
• Kim Seonhye
• Min Se-Won
• Son Hyunjung
• Choi Utah

Classifications

• G02F1/1368

  in which the switching element is a three-electrode device {(G02F1/136277 takes precedence)} · CPC title

• G09G3/3696 Primary

  Generation of voltages supplied to electrode drivers · CPC title

• G02F2201/123

  pixel · CPC title

• G09G2310/08

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

• G09G2310/0245

  Clearing or presetting the whole screen independently of waveforms, e.g. on power-on (G09G2310/063 takes precedence) · CPC title