Transparent liquid crystal display apparatus and method of driving the same

Patent metadata

Field	Value
Publication number	US-10163415-B2
Application number	US-201615371060-A
Country	US
Kind code	B2
Filing date	Dec 6, 2016
Priority date	Jan 19, 2016
Publication date	Dec 25, 2018
Grant date	Dec 25, 2018

Abstract

A method of driving a transparent liquid crystal display apparatus includes a transparent display panel including a brightness sensor and a timing controller. The timing controller includes a YCbCr converter configured to convert input pixel data to YCbCr data, a histogram extractor configured to receive the YCbCr data and generate histogram information about the number of values corresponding to each of brightness data, a grayscale analysis unit configured to analyze the histogram information and determine a type of an input image, an image processer configured to process the YCbCr data according to the type of the input image and the ambient brightness information and generate an output YCbCr′ data, and an RGB converter configured to convert the output YCbCr′ data to output image data.

First claim

What is claimed is:

1. A transparent liquid crystal display apparatus, comprising:
a transparent display panel comprising a liquid crystal layer;
a timing controller configured to receive an input image data and output an output image data; and
a brightness sensor configured to sense a brightness of an ambient light and provide an ambient brightness information to the timing controller,
wherein the input image data comprises a plurality of input pixel data, each of which comprises a red grayscale data, a green grayscale data and a blue grayscale data, and
wherein the timing controller comprises:
a YCbCr converter configured to convert the input pixel data to YCbCr data, wherein the YCbCr data comprises YCbCr pixel data for a plurality of pixels, and each of the YCbCr data has a brightness data corresponding to a pixel of the plurality of pixels;
a histogram extractor configured to receive the YCbCr data and generate a histogram information comprising a number of values corresponding to each of the brightness data;
a grayscale analysis unit configured to analyze the histogram information and determine a type of an input image by counting a number of low brightness values from the histogram information, and counting a number of high brightness values from the histogram information, wherein the low brightness values are each smaller than a reference low brightness, and the high brightness values are each greater than a reference high brightness, wherein a number of middle brightness values is determined by subtracting a sum of the number of low brightness values and the number of high brightness values from a total number of brightness values of the histogram information, wherein the type of the input image is determined as the V-type when a ratio of the number of middle brightness values to the total number of the brightness values is smaller than a reference low ratio, and wherein the type of the input image is determined as the A-type when a ratio of the number of middle brightness values to the total number of the brightness values is larger than a reference high ratio;
an image processer configured to process the YCbCr data according to the type of the input image and the ambient brightness information and generate an output YCbCr′ data; and
an RGB converter configured to convert the output YCbCr′ data to the output image data, wherein the output image data comprises an output pixel data each of which comprises a red grayscale data, a green grayscale data and a blue grayscale data.

2. The transparent liquid crystal display apparatus of claim 1 ,
wherein the grayscale analysis unit determines the type of the input image as an A-type when a frequency distribution of the histogram information is relatively high at a middle of the frequency distribution, and
wherein the grayscale analysis unit is further configured to determine the type of the input image as a V-type when the frequency distribution of the histogram information is relatively low at the middle of the frequency distribution.

3. The transparent liquid crystal display apparatus of claim 1 , wherein the brightness data is from 0 to 255, the reference low brightness is 85, the reference high brightness is 170, the reference low ratio is 30%, and the reference high ratio is 70%.

4. The transparent liquid crystal display apparatus of claim 1 , further comprising a LUT storage unit which stores a lookup table having an input to output mapping information for each of the type of the input image.

5. The transparent liquid crystal display apparatus of claim 4 , wherein in the lookup table, an output range corresponding to a brightness data range having more image information is set to be widened, and an output range corresponding to a brightness data range having less image information is set to be narrowed.

6. The transparent liquid crystal display apparatus of claim 5 , wherein the LUT storage unit further comprises a bypass lookup table which outputs an input value as it is.

7. A transparent liquid crystal display apparatus, comprising:
a transparent display panel comprising a liquid crystal layer;
a timing controller configured to receive an input image data and output an output image data; and
a brightness sensor configured to sense a brightness of an ambient light and provide an ambient brightness information to the timing controller,
wherein the input image data comprises a plurality of input pixel data, each of which comprises a red grayscale data, a green grayscale data and a blue grayscale data, and
wherein the timing controller comprises:
a YCbCr converter configured to convert the input pixel data to YCbCr data, wherein the YCbCr data comprises YCbCr pixel data for a plurality of pixels, and each of the YCbCr data has a brightness data corresponding to a pixel of the plurality of pixels;
a histogram extractor configured to receive the YCbCr data and generate a histogram information comprising a number of values corresponding to each of the brightness data;
a grayscale analysis unit configured to analyze the histogram information and determine a type of an input image;
an image processer configured to process the YCbCr data according to the type of the input image and the ambient brightness information and generate an output YCbCr′ data;
an RGB converter configured to convert the output YCbCr′ data to output image data, wherein the output image data comprises an output pixel data each of which comprises a red grayscale data, a green grayscale data and a blue grayscale data; and

a LUT storage unit which stores a lookup table having an input to output mapping information for each of the type of the input image,
wherein the LUT storage unit further comprises a bypass lookup table which outputs an input value as it is,
wherein in the lookup table, an output range corresponding to a brightness data range having more image information is set to be widened, and an output range corresponding to a brightness data range having less image information is set to be narrowed,
wherein the image processer generates the output YCbCr′ data which comprises output brightness data using the equation below:
output brightness data Y ′=bypass lookup table( Y )+(lookup table( Y )−bypass lookup table ( Y ))*weight factor WF  [equation]

(Here, the bypass lookup table(Y) means output of the bypass lookup table corresponding to the input brightness data Y,
lookup table(Y) means output of the lookup table for each of the type of the input image corresponding to the input brightness data Y,
weight factor WF has a value 0 to 1 according to the ambient brightness information).

8. A method of driving a transparent liquid crystal display apparatus, comprising:
converting an input image to a YCbCr data;
extracting a histogram comprising a brightness data from the YCbCr data;
analyzing the histogram to determine a type of the input image, wherein analyzing the histogram produces a histogram information, and comprises:
counting a number of low brightness values from the histogram information and counting a number of high brightness values from the histogram information, and
wherein the low brightness values are each smaller than a reference low brightness, and the high brightness values are each greater than a reference high brightness,
wherein a number of middle brightness values is determined by subtracting a sum of the number of low brightness values and the number of high brightness values from atotala total number of brightness values of the histogram information,
wherein the type of the input image is determined as the V-type when a ratio of a number of middle brightness values to the total number of the brightness values is smaller than a reference low ratio,
wherein the type o

Assignees

• Samsung Display Co Ltd
• Samsung Display Co Ltd

Inventors

• Jeon Jae-Gwan
• Park Suk Jin
• Choi Nam-Gon
• Takegama Akihiro

Classifications

• C03B23/245

  Hollow glass sheets · CPC title

• G09G3/2007 Primary

  Display of intermediate tones · CPC title

• G09G2320/0276

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

• G09G2360/16

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

• E06B3/66314

  of tubular shape (E06B3/66323 and E06B3/66333 take precedence) · CPC title