Display apparatus and method of driving the same based on representative grayscale of frame

Patent metadata

Field	Value
Publication number	US-10453418-B2
Application number	US-201715824349-A
Country	US
Kind code	B2
Filing date	Nov 28, 2017
Priority date	Mar 8, 2017
Publication date	Oct 22, 2019
Grant date	Oct 22, 2019

Abstract

A display apparatus includes a timing controller, a common voltage generator, a data driver, and a display panel. The timing controller determines a representative grayscale of each frame based on input image data and generates a common voltage control signal having a first digital value ratio (“DVR”) value corresponding to a first frame, a representative grayscale of the first frame being included in a first grayscale range. The common voltage generator generates a first common voltage based on the common voltage control signal. The data driver generates a data voltage based on the input image data. The display panel displays an image corresponding to the first frame based on the data voltage and the first common voltage.

First claim

What is claimed is:

1. A display apparatus comprising:
a timing controller which determines a representative grayscale of each frame based on input image data and generates a common voltage control signal having a first digital value ratio value corresponding to a first frame, a representative grayscale of the first frame being included in a first grayscale range;
a common voltage generator which generates a first common voltage based on the common voltage control signal;
a data driver which generates a data voltage based on the input image data; and
a display panel which displays an image corresponding to the first frame based on the data voltage and the first common voltage,
wherein the first common voltage satisfies an equation below:

VCOM
=

VCOM
M

-

DVR
+
1

DVR
M

+
1

⁢

VCOM
R

,

where VCOM denotes the first common voltage, VCOM M denotes a maximum available value of a common voltage, VCOM R denotes a variable range of a common voltage, DVR M denotes a maximum digital value ratio value, DVR denotes the first digital value ratio value.

2. The display apparatus of claim 1 , wherein the first grayscale range is a grayscale range to display a dark skin color (Dark Skin).

3. The display apparatus of claim 2 , wherein a red grayscale of the first grayscale range is greater than or equal to 91 and less than or equal to 97, a green grayscale of the first grayscale range is greater than or equal to 25 and less than or equal to 31, and a blue grayscale of the first grayscale range is greater than or equal to 10 and less than or equal to 16, and
wherein a maximum of the red grayscale, the green grayscale and the blue grayscale is 256.

4. The display apparatus of claim 2 , wherein the first digital value ratio value is greater than or equal to 64 and less than or equal to 88, and
wherein a maximum of the first digital value ratio value is 127.

5. The display apparatus of claim 1 , wherein the first grayscale range is a grayscale range to display a first light skin color (Light Skin 1).

6. The display apparatus of claim 5 , wherein a red grayscale of the first grayscale range is greater than or equal to 194 and less than or equal to 200, a green grayscale of the first grayscale range is greater than or equal to 148 and less than or equal to 154, and a blue grayscale of the first grayscale range is greater than or equal to 127 and less than or equal to 133, and
wherein a maximum of the red grayscale, the green grayscale and the blue grayscale is 256.

7. The display apparatus of claim 5 , wherein the first digital value ratio value is greater than or equal to 77 and less than or equal to 101, and
wherein a maximum of the first digital value ratio value is 127.

8. The display apparatus of claim 1 , wherein the first grayscale range is a grayscale range to display a light skin color (Light Skin 2).

9. The display apparatus of claim 8 , wherein a red grayscale of the first grayscale range is greater than or equal to 238 and less than or equal to 244, a green grayscale of the first grayscale range is greater than or equal to 146 and less than or equal to 152, and a blue grayscale of the first grayscale range is greater than or equal to 105 and less than or equal to 111, and
wherein a maximum of the red grayscale, the green grayscale and the blue grayscale is 256.

10. The display apparatus of claim 8 , wherein the first digital value ratio value is greater than or equal to 64 and less than or equal to 88, and
wherein a maximum of the first digital value ratio value is 127.

11. The display apparatus of claim 1 , wherein
the common voltage control signal has a second digital value ratio value corresponding to a second frame, a representative grayscale of the second frame being included in a second grayscale range different from the first grayscale range,
the common voltage generator which further generates a second common voltage based on the common voltage control signal, and
the display panel which displays an image corresponding to the second frame based on the data voltage and the second common voltage.

12. The display apparatus of claim 1 , wherein the timing controller generates a grayscale histogram of each frame based on the input image data and analyzes the grayscale histogram to determine the representative grayscale of each frame.

13. The display apparatus of claim 12 , wherein the timing controller generates the grayscale histogram of each of a red grayscale, a green grayscale and a blue grayscale.

14. The display apparatus of claim 12 , wherein the representative grayscale of each frame is a most frequent grayscale of each frame.

15. The display apparatus of claim 1 , wherein the display panel displays the image according to an intensity of an electric field generated by the first common voltage and the data voltage.

16. A method of driving a display apparatus, the method comprising:
determining a representative grayscale of each frame based on input image data;
generating a common voltage control signal having a first digital value ratio value corresponding to a first frame, a representative grayscale of the first frame being included in a first grayscale range;
generating a first common voltage based on the common voltage control signal;
generating a data voltage based on the input image data; and
displaying an image corresponding to the first frame based on the data voltage and the first common voltage,
wherein the first common voltage satisfies an equation below:

VCOM
=

VCOM
M

-

DVR
+
1

DVR
M

+
1

⁢

VCOM
R

,

where VCOM denotes the first common voltage, VCOM M denotes a maximum available value of a common voltage, VCOM R denotes a variable range of a common voltage, DVR M denotes a maximum digital value ratio value, DVR denotes the first digital value ratio value.

17. The method of claim 16 , wherein the first grayscale range is a grayscale range to display a dark skin color (Dark S

Assignees

• Samsung Display Co Ltd

Inventors

• Lim Han-Byul
• Moon Seunghwan
• Sim Myungbo
• Lee Junpyo

Classifications

• G09G2320/043

  Preventing or counteracting the effects of ageing · CPC title

• G09G2320/0247

  Flicker reduction other than flicker reduction circuits used for single beam cathode-ray tubes · CPC title

• G09G2320/0209

  Crosstalk reduction, i.e. to reduce direct or indirect influences of signals directed to a certain pixel of the displayed image on other pixels of said image, inclusive of influences affecting pixels in different frames or fields or sub-images which constitute a same image, e.g. left and right images of a stereoscopic display · CPC title

• G09G5/02

  characterised by the way in which colour is displayed {(details of colour display specific for CRTs G09G1/28; specific for flat matrix panels other than liquid crystal displays G09G3/2003; specific for liquid crystal displays G09G3/3607)} · CPC title

• G09G2320/0271

  Adjustment of the gradation levels within the range of the gradation scale, e.g. by redistribution or clipping · CPC title