Display device

Patent metadata

Field	Value
Publication number	US-10650772-B2
Application number	US-201816166915-A
Country	US
Kind code	B2
Filing date	Oct 22, 2018
Priority date	Oct 25, 2017
Publication date	May 12, 2020
Grant date	May 12, 2020

Abstract

A display device includes: a display panel comprising a display area configured to display an image, wherein the display area includes a measurement area including a plurality of sub-measurement areas, and each of the plurality of sub-measurement areas includes a plurality of pre-map areas; a data driver configured to provide data voltages to the display panel; a signal controller; and a common voltage generator configured to provide a common voltage to the display panel, wherein an afterimage reduction mode is driven to change a level of the common voltage provided by the common voltage generator when the determined pre-map areas are adjacent to each other.

First claim

What is claimed is:

1. A display device comprising:
a display panel comprising a display area configured to display an image, wherein the display area comprises a measurement area comprising a plurality of sub- measurement areas, and each of the plurality of sub-measurement areas comprises a plurality of pre-map areas;
a data driver configured to provide data voltages to the display panel;
a signal controller configured to:
sequentially select the plurality of sub-measurement areas in response to a change in frame;
calculate first average values respectively corresponding to the pre-map areas by using data voltages applied to the selected sub-measurement area at a first time point to generate first average value data;
calculate second average values respectively corresponding to the pre- map areas by using data voltages applied to the selected sub-measurement area at a second time point after a predetermined time from the first time point to generate second average value data; and
compare the first average value data with the second average value data to determine pre-map areas, the first average values of which are equal to the second average values thereof, among the pre-map areas; and

a common voltage generator configured to provide a common voltage to the display panel,
wherein an afterimage reduction mode is driven to change a level of the common voltage provided by the common voltage generator when the determined pre-map areas are adjacent to each other.

2. The display device of claim 1 , wherein the display panel comprises:
a liquid crystal layer;
a plurality of pixel electrodes arranged to correspond to the liquid crystal layer and to which the data voltages are applied; and
a common electrode arranged to correspond to the liquid crystal layer, which overlaps with the plurality of pixel electrodes, and to which the common voltage is applied.

3. The display device of claim 2 , wherein the level of the common voltage is reduced.

4. The display device of claim 3 , wherein each of the first average values and the second average values is an average value of a red data signal value, a green data signal value and a blue data signal value.

5. The display device of claim 3 , wherein a level of each of the data voltages is reduced when the afterimage reduction mode is driven.

6. The display device of claim 3 , further comprising:
a gamma voltage generator configured to provide a plurality of gamma voltages to the data driver,
wherein a level of each of the plurality of gamma voltages is reduced when the afterimage reduction mode is driven.

7. The display device of claim 3 , wherein the measurement area is adjacent to an edge of the display area.

8. The display device of claim 3 , wherein the measurement area is provided in plurality and the plurality of measurement areas comprises:
a first measurement area in a top left portion of the display area;
a second measurement area in a top right portion of the display area;
a third measurement area in a bottom left portion of the display area; and
a fourth measurement area in a bottom right portion of the display area.

9. The display device of claim 3 , further comprising:
a memory configured to store a first cumulative time for which the determined pre-map areas are adjacent to each other,
wherein the afterimage reduction mode is driven when the first cumulative time is equal to or greater than a first time value.

10. The display device of claim 9 , wherein the memory is further configured to store a second cumulative time for which the afterimage reduction mode is driven, and the level of the common voltage is further reduced when a sum of the first cumulative time and the second cumulative time is equal to or greater than a second time value greater than the first time value.

11. The display device of claim 1 , wherein, when the signal controller detects that the image includes a pattern in which a white color and a black color are repeated, a difference in level between the common voltage and a data voltage corresponding to the white color is reduced.

12. A display device comprising:
a display panel comprising:
a liquid crystal layer;
a plurality of pixel electrodes arranged to correspond to the liquid crystal layer; and
a common electrode arranged to correspond to the liquid crystal layer,

wherein a display area configured to display an image is defined in the display panel;
a common voltage generator configured to provide a common voltage to the common electrode; and
a data driver configured to provide a data voltage inverted with reference to the common voltage to the plurality of pixel electrodes,
wherein a driving mode of the display device comprises:
an afterimage reduction mode driven when the image includes a pattern in which a white color and a black color are repeated; and
a normal mode driven when the image does not include the pattern, and

wherein an absolute value of a difference between a level of the common voltage and a level of the data voltage for displaying the white color in the afterimage reduction mode is smaller than an absolute value of a difference between a level of the common voltage and a level of the data voltage for displaying the white color in the normal mode.

13. The display device of claim 12 , further comprising:
a signal controller configured to provide a data signal corresponding to the data voltage to the data driver,
wherein the display area comprises a measurement area comprising a plurality of sub-measurement areas, and each of the plurality of sub-measurement areas comprises a plurality of pre-map areas,
wherein the signal controller is configured to sequentially select the plurality of sub-measurement areas in response to a change in frame,
wherein the signal controller is configured to calculate first average values respectively corresponding to the pre-map areas by using data voltages applied to the selected sub-measurement area at a first time point to generate first average value data,
wherein the signal controller is configured to calculate second average values respectively corresponding to the pre-map areas by using data voltages applied to the selected sub-measurement area at a second time point after a predetermined time from the first time point to generate second average value data,
wherein the signal controller is configured to compare the first average value data with the second average value data to determine pre-map areas, the first average values of which are equal to the second average values thereof, among the pre-map areas, and
wherein a level of the common voltage provided by the common voltage generator is changed when the determined pre-map areas are adjacent to each other.

14. The display device of claim 13 , wherein the level of the common voltage is reduced.

15. The display device of claim 14 , wherein each of the first average values and the second average values is an average value of a red data signal value, a green data signal value and a blue data signal value.

16. The display device of claim 14 , wherein the measurement area is adjacent to an edge of the display area.

17. The display device of claim 14 , wherein the measurement area is provided in plurality and the plurality of measurement areas comprises:
a first measurement area in a top left portion of the display area;
a second measurement area in a top right portion of the display area;
a third measurement area in a bottom left portion of the display area; and
a fourth measurement area in a bottom right portion of the display area.

Assignees

• Samsung Display Co Ltd

Inventors

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

Classifications

• G02F2201/121

  common or background · CPC title

• G09G2320/0257

  Reduction of after-image effects · CPC title

• G09G2360/16

  Calculation or use of calculated indices related to luminance levels in display data · CPC title

• G09G3/3648

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

• G02F1/133514

  Colour filters · CPC title