Display device with improved display quality

Patent metadata

Field	Value
Publication number	US-9799260-B2
Application number	US-201514729320-A
Country	US
Kind code	B2
Filing date	Jun 3, 2015
Priority date	Jan 30, 2015
Publication date	Oct 24, 2017
Grant date	Oct 24, 2017

Abstract

A display device includes a display panel, a dither table memory device, a dithering processor, and a display panel driver. The display panel includes a plurality of pixels. Dither tables are stored in the dither table memory device. The dithering processor selects a target dither table corresponding to a grayscale level of input data from among the plurality of dither tables and performs a dithering operation on the input data using the target dither table to generate dither data. The display panel driver drives the display panel based on the generated dither data.

First claim

What is claimed is:

1. A display device comprising:
a display panel including a plurality of pixels;
a dither table memory device, in which a plurality of dither tables are stored, wherein each of the dither tables includes a plurality of dither patterns, wherein each of the dither patterns is formed by patterning a plurality of sub-grayscale values to represent a dither grayscale value, wherein the dither tables includes a normal dither table and an altered dither table, and wherein the altered dither table excludes at least one of the sub-grayscale values included in the normal dither table;
a dithering processor configured to:
select a target dither table corresponding to a grayscale level of input data from among the plurality of dither tables, and to perform a dithering operation on the input data using the target dither table to generate dither data;
determine an input data grayscale region corresponding to the grayscale level of the input data among a plurality of grayscale regions, the grayscale regions divided based on at least one threshold grayscale level;
select the target dither table corresponding to the input data grayscale region from among the plurality of dither tables; and
generate the dither data by performing the dithering operation on the input data using the target dither table; and

a display panel driver configured to drive the display panel based on the generated dither data and by a digital driving technique that represents a grayscale using a plurality of sub-fields for which time weights are different from each other, wherein the at least one threshold grayscale level is adjusted based on the time weights of the sub-fields.

2. The display device of claim 1 , wherein the dithering processor is further configured to:
determine a delay region in which a resistor-capacitor (RC) delay occurs and a non-delay region in which the RC delay does not occur, based on a position of the input data on the display panel.

3. The display device of claim 2 , wherein the dithering processor is configured to select the normal dither table as the target dither table when the input data corresponds to the non-delay region.

4. The display device of claim 1 , wherein the altered dither table excludes a minimum sub-grayscale value corresponding to a minimum sub-field of which time weight is smallest among the time weights of the sub-fields.

5. The display device of claim 1 , wherein the time weights of the sub-fields are adjusted based on a distribution of the input data.

6. A display device comprising:
a display panel including a plurality of pixels;
a dither table memory device, in which a plurality of dither tables are stored, wherein each of the dither tables includes a plurality of dither patterns, wherein each of the dither patterns is formed by patterning a plurality of sub-grayscale values to represent a dither grayscale value;
a dithering processor configured to:
select a target dither table corresponding to a grayscale level of input data from among the plurality of dither tables, and to perform a dithering operation on the input data using the target dither table to generate dither data;
determine an input data grayscale region corresponding to the grayscale level of the input data among a plurality of grayscale regions, the grayscale regions divided based on at least one threshold grayscale level;
select the target dither table corresponding to the input data grayscale region from among the plurality of dither tables; and
generate the dither data by performing the dithering operation on the input data using the target dither table; and

a display panel driver configured to drive the display panel based on the generated dither data,
wherein the dither tables includes a normal dither table and an altered dither table,
wherein the altered dither table excludes at least one of the sub-grayscale values included in the normal dither table,
wherein the grayscale regions includes a first grayscale region, a second grayscale region, and a third grayscale region,
wherein the first grayscale region and the second grayscale region are divided based on the basis of a first threshold grayscale level,
wherein the second grayscale region and the third grayscale region are divided based on the basis of a second threshold grayscale level, and
wherein the second threshold grayscale level is higher than the first threshold grayscale level.

7. The display device of claim 6 , wherein the dithering processor is configured to select the normal dither table as the target dither table when the input data grayscale region is included in the first grayscale region or the third grayscale region.

8. The display device of claim 6 , wherein the dithering processor is configured to select the altered dither table as the target dither table when the input data grayscale region is included in the second grayscale region.

9. A display device comprising:
a display panel including a plurality of pixels;
a dither table memory device, in which a plurality of dither tables are stored, wherein each of the dither tables includes a plurality of dither patterns, and wherein each of the dither patterns is formed by patterning a plurality of sub-grayscale values to represent a dither grayscale value;
a dithering processor configured to:
select a target dither table corresponding to a position of input data on the display panel from among the plurality of dither tables, and to perform a dithering operation on the input data using the target dither table to generate dither data;
determine a delay region in which a resistor-capacitor (RC) delay occurs and a non-delay region in which the RC delay does not occur, based on the position of the input data on the display panel;
select the normal dither table as the target dither table when the input data corresponds to the non-delay region, and select the altered dither table as the target dither table when the input data corresponds to the delay region; and
generate the dither data by performing the dithering operation on the input data using the target dither table; and

a display panel driver configured to drive the display panel based on the generated dither data.

10. The display device of claim 9 , wherein the dither tables includes a normal dither table and an altered dither table, and wherein the altered dither table excludes at least one of the sub-grayscale values included in the normal dither table.

11. The display device of claim 10 , wherein the display panel driver drives the display panel by a digital driving technique that represents a grayscale using a plurality of sub-fields for which time weights are different from each other.

12. The display device of claim 11 , wherein the altered dither table excludes a minimum sub-grayscale value corresponding to a minimum sub-field of which time weight is smallest among the time weights of the sub-fields.

13. The display device of claim 11 , wherein the time weights of the sub-fields are adjusted based on a distribution of the input data.

Assignees

• Samsung Display Co Ltd

Inventors

• Song Jae-Woo
• Park Seung-Ho
• Lee Kang-Hee
• Joo Mi-Young
• Lee Jae-Hoon

Classifications

• G09G3/2055

  the pattern being varied in time · CPC title

• G09G2320/0223

  Compensation for problems related to R-C delay and attenuation in electrodes of matrix panels, e.g. in gate electrodes or on-substrate video signal electrodes · CPC title

• G09G2320/0266

  Reduction of sub-frame artefacts · CPC title

• G09G3/003

  to produce spatial visual effects · CPC title

• G09G3/2092 Primary

  Details of a display terminals using a flat panel, the details relating to the control arrangement of the display terminal and to the interfaces thereto (suitable for both CRT and flat panel G09G5/003; specific for a CRT G09G1/165) · CPC title