Display apparatus having increased side-visibility in a high grayscale range and a method of driving the same

Patent metadata

Field	Value
Publication number	US-10475411-B2
Application number	US-201615072905-A
Country	US
Kind code	B2
Filing date	Mar 17, 2016
Priority date	Sep 23, 2015
Publication date	Nov 12, 2019
Grant date	Nov 12, 2019

Abstract

A display apparatus includes: a display panel including a data line, a gate line crossing the data line, and a sub pixel connected to the data line and the gate line; a gamma data generator configured to output normal gamma data of a normal gamma curve corresponding to image data when a grayscale of the image data is inside a first grayscale range, and to output high gamma data of a high gamma curve or low gamma data of a low gamma curve based on a spatio-temporal pattern when the grayscale of the image data is outside the first grayscale range; and a data driver configured to convert the gamma data outputted from the gamma data generator to a data voltage and to output the data voltage to the data line.

First claim

What is claimed is:

1. A display apparatus, comprising:
a display panel comprising a data line, a gate line crossing the data line, and a sub pixel connected to the data line and the gate line;
a gamma data generator configured to output normal gamma data of a normal gamma curve corresponding to image data when a grayscale of the image data is inside a first grayscale range, and to output high gamma data of a high gamma curve and low gamma data of a low gamma curve based on a spatio-temporal pattern when the grayscale of the image data is outside the first grayscale range; and
a data driver configured to convert the gamma data outputted from the gamma data generator to a data voltage and to output the data voltage to the data line,
wherein the first grayscale range comprises a middle grayscale range including middle grayscales which are between low grayscales and high grayscales,
wherein the gamma data generator is configured to output high gamma data of a high gamma curve and low gamma data of a low gamma curve when the grayscale of the image data is inside a high grayscale range, and
to output the high gamma data of the high gamma curve and the low gamma data of the low gamma curve when the grayscale of the image data is inside a low grayscale range.

2. The display apparatus of claim 1 , wherein the gamma data generator comprises a combined gamma look-up table (LUT), wherein the combined gamma LUT comprises the normal gamma data of the normal gamma curve corresponding to the middle grayscale range, the high gamma data of the high gamma curve corresponding to the high grayscale range and the low gamma data of the low gamma curve corresponding to the low grayscale range.

3. The display apparatus of claim 2 , wherein the combined gamma LUT comprises first high gamma data of a first modified high gamma curve which gradually connects the high gamma curve and the normal gamma curve in a first boundary grayscale range between the middle grayscale range and the low grayscale range, first low gamma data of a first modified low gamma curve which gradually connects the low gamma curve and the normal gamma curve in the first boundary grayscale range, second high gamma data of a second modified high gamma curve which gradually connects the high gamma curve and the normal gamma curve in a second boundary grayscale range between the middle grayscale range and the high grayscale range, and second low gamma data of a second modified low gamma curve which gradually connects the low gamma curve and the normal gamma curve in the second boundary grayscale range.

4. The display apparatus of claim 3 , wherein the gamma data generator is configured to output the first high gamma data of the first modified high gamma curve and the first low gamma data of the first modified low gamma curve when the grayscale of the image data is inside the first boundary grayscale range, and
to output the second high gamma data of the second modified high gamma curve and the second low gamma data of the second modified low gamma curve when the grayscale of the image data is inside the second boundary grayscale range.

5. The display apparatus of claim 1 , wherein the gamma data generator comprises:
a high gamma look-up table (LUT) configured to store high gamma data grayscales based on the high gamma curve;
a low gamma LUT configured to store low gamma data grayscales based on the low gamma curve; and
a normal gamma LUT configured to store normal gamma data grayscales based on the normal gamma curve.

6. A method of driving a display apparatus, comprising:
outputting normal gamma data of a normal gamma curve corresponding to image data when a grayscale of the image data is inside a first grayscale range, the image data corresponding to a sub pixel connected to a data line and a gate line;
outputting high gamma data of a high gamma curve and low gamma data of a low gamma curve based on a spatio-temporal pattern when the grayscale of the image data is outside the first grayscale range; and
converting the outputted gamma data to a data voltage and outputting the data voltage to the data line,
wherein the first grayscale range comprises a middle grayscale range including middle grayscales which are between low grayscales and high grayscales, wherein the method further comprises:
outputting the high gamma data of the high gamma curve and the low gamma data of the low gamma curve when the grayscale of the image data is inside a high grayscale range, and
outputting the high gamma data of the high gamma curve and the low gamma data of the low gamma curve when the grayscale of the image data is inside a low grayscale range.

7. The method of claim 6 , wherein the normal, high and low gamma data are outputted using a combined gamma look-up table (LUT) comprising the normal gamma data of the normal gamma curve corresponding to the middle grayscale range, the high gamma data of the high gamma curve corresponding to the high grayscale range and the low gamma data of the low gamma curve corresponding to the low grayscale range.

8. The method of claim 7 , wherein the combined gamma LUT comprises first high gamma data of a first modified high gamma curve which gradually connects the high gamma curve and the normal gamma curve in a first boundary grayscale range between the middle grayscale range and the low grayscale range, first low gamma data of a first modified low gamma curve which gradually connects the low gamma curve and the normal gamma curve in the first boundary grayscale range, second high gamma data of a second modified high gamma curve which gradually connects the high gamma curve and the normal gamma curve in a second boundary grayscale range between the middle grayscale range and the high grayscale range, and second low gamma data of a second modified low gamma curve which gradually connects the low gamma curve and the normal gamma curve in the second boundary grayscale range.

9. The method of claim 8 , further comprising:
outputting the first high gamma data of the first modified high gamma curve and the first low gamma data of the first modified low gamma curve when the grayscale of the image data is inside the first boundary grayscale range, and
outputting the second high gamma data of the second modified high gamma curve and the second low gamma data of the second modified low gamma curve when the grayscale of the image data is inside the second boundary grayscale range.

10. The method of claim 6 , wherein the high gamma data are outputted using a high gamma look-up table (LUT) configured to store high gamma data grayscales based on the high gamma curve, the low gamma data are outputted using a low gamma LUT configured to store low gamma data grayscales based on the low gamma curve, and the normal gamma data are outputted using a normal gamma LUT configured to store normal gamma data grayscales based on the normal gamma curve.

Assignees

• Samsung Display Co Ltd

Inventors

• Kang Bong-Gyun
• Choi Nam-Gon
• Shin Dong Hwa
• Kim Gi Geun
• Bae Jae-Sung

Classifications

• G09G3/3685 Primary

  Details of drivers for data electrodes · CPC title

• G09G2320/0673

  for control of gamma adjustment, e.g. selecting another gamma curve · CPC title

• G09G3/3648 Primary

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

• G09G2320/10

  Special adaptations of display systems for operation with variable images · CPC title

• G09G2320/0276

  for the purpose of adaptation to the characteristics of a display device, i.e. gamma correction · CPC title