Video display device capable of compensating for display defects

• US 20080309602A1
• Filed: 06/03/2008
• Published: 12/18/2008
• Est. Priority Date: 06/14/2007
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Display Co., Ltd.
• Inventors: Hwang, Jong Hee
• Granted Patent: US 10,810,918 B2
• Time in Patent Office: Days
• US Class Current: 345/89
• CPC Class Codes: G09G 2330/10 Dealing with defective pixels
• CPC Class Codes: G09G 3/006 Electronic inspection or testing of displays and display drivers, e.g. of LED or LCD displays testing individual LED's G01R31/2635; testing lamps G01R31/44; testing of optical features of LCD displays G02F1/1309
• CPC Class Codes: G09G 3/2055 the pattern being varied in time

Abstract

A video display device capable of compensating for display defects, comprising: liquid crystal panel for displaying an image through a pixel matrix; a data driver for outputting data to data lines of the liquid crystal display panel; a gate driver for driving the gate lines of the liquid crystal display panel; a timing controller for receiving compensated data, uncompensated data and synchronizing signals to output a gate control signal to the gate driver and to output both resultant data and a data control signal to the data driver; and a memory for storing information on point defect information on the liquid crystal display panel, and at least one of horizontal and vertical line defects of the liquid crystal display panel of the liquid crystal display panel; and a data compensation circuit for receiving display data and synchronizing signals, and outputting compensated data to the timing controller based on the information in the memory and uncompensated data to the timing controller, wherein the data compensation circuit includes a vertical line compensator for compensating a vertical line defect of the liquid crystal display panel, a horizontal line compensator for compensating a horizontal line defect of the liquid crystal display panel, and a multiplexer for selecting an output from one of the vertical line compensator and the horizontal line compensator in accordance with whether a defect is a vertical line defect or a horizontal line defect.

Claims

1. A video display device capable of compensating for display defects, comprising:

liquid crystal panel for displaying an image through a pixel matrix;

a data driver for outputting data to data lines of the liquid crystal display panel;

a gate driver for driving the gate lines of the liquid crystal display panel;

a timing controller for receiving compensated data, uncompensated data and synchronizing signals to output a gate control signal to the gate driver and to output both resultant data and a data control signal to the data driver; and

a memory for storing information on point defect information on the liquid crystal display panel, and at least one of horizontal and vertical line defects of the liquid crystal display panel of the liquid crystal display panel; and

a data compensation circuit for receiving display data and synchronizing signals, and outputting compensated data to the timing controller based on the information in the memory and uncompensated data to the timing controller,

wherein the data compensation circuit includes a vertical line compensator for compensating a vertical line defect of the liquid crystal display panel, a horizontal line compensator for compensating a horizontal line defect of the liquid crystal display panel, and a multiplexer for selecting an output from one of the vertical line compensator and the horizontal line compensator in accordance with whether a defect is a vertical line defect or a horizontal line defect.

2. The video display device capable of compensating for display defects according to claim 1, wherein the information includes position information, grayscale information and compensation data on the at least one of horizontal and vertical line defects of the liquid crystal display panel.

3. The video display device capable of compensating for display defects according to claim 2, wherein the information also includes direction information about the defect.

4. The video display device capable of compensating for display defects according to claim 2, wherein the information also includes order information and brightness information about the defect.

5. The video display device capable of compensating for display defects according to claim 1, wherein the information includes position information, grayscale information and compensation data on point defect regions of the liquid crystal display panel.

6. The video display device capable of compensating for display defects according to claim 1, wherein the horizontal line compensator and the vertical line compensator receive the display data and compensate based on the defect having a main region and boundary regions, and output a first compensated signal.

7. The video display device capable of compensating for display defects according to claim 6, further comprising a fine compensator for receiving the first compensated signal and further compensating based on the first compensation signal being spatially and temporally distributed in accordance with a frame rate control dithering method, and output compensated data.

8. The video display device capable of compensating for display defects according to claim 7, wherein the fine compensator includes:

a frame determiner for counting pulses of a vertical synchronizing signal to detect a number of frames;

a pixel position determiner for determining pixel position information from the first compensated signal using at least one of the synchronizing signals;

a dither value selector for selecting dither values using the first compensated signal, the number of frames from the frame determiner, and the pixel position information output from the pixel position determiner; and

an adder for adding dither values from the dither value selector to the first compensated signal and then outputting resultant data.

9. The video display device capable of compensating for display defects according to claim 1, further comprising a point defect compensator that receives display data and compensates based on point defect information in the memory and outputs compensated data.

10. The video display device capable of compensating for display defects according to claim 9, wherein the point defect compensator includes:

a grayscale determiner for analyzing respective grayscale levels of the display data to be supplied to a link pixel of a point defect region, selecting grayscale range information corresponding to display data from the memory, and outputting a selected grayscale range information;

a position determiner for determining a pixel position from the display data using at least one of the synchronizing signals and outputting pixel information;

a compensation data selector for selecting compensation data output from memory base on the selected grayscale range information from the grayscale determiner and the pixel information from the position determiner; and

a calculator for one of adding and subtracting the compensation data output to the display data to output resultant data.

11. The video display device capable of compensating for display defects according to claim 1, wherein each of the vertical and horizontal line compensators include:

a grayscale determiner for analyzing respective grayscale levels of the display data to be supplied to a link pixel of a point defect region, selecting grayscale range information corresponding to display data from the memory, and outputting a selected grayscale range information;

a position determiner for determining a pixel position from the display data using at least one of the synchronizing signals and outputting pixel information;

a compensation data selector for selecting compensation data output from memory base on the selected grayscale range information from the grayscale determiner and the pixel information from the position determiner;

an adder for adding the compensation data output to the display data to output resultant data;

a subtractor for subtracting the compensation data output from the display data to output resultant data;

a first multiplexer sequentially outputs the brightness information for typical defect regions in accordance with an order of the defect stored in the memory; and

a second multiplexer for selecting the output resultant data from one of the adder and the output resultant data from the subtractor in accordance with the brightness information and outputs the selected resultant data.

20. The video display device capable of compensating for display defects according to claim 1, further comprising a point defect compensator that receives display data and compensates based on point defect information in the memory and outputs compensated data.

12. A video display device capable of compensating for display defects, comprising:

liquid crystal panel for displaying an image through a pixel matrix;

a data driver for outputting data to data lines of the liquid crystal display panel;

a gate driver for driving the gate lines of the liquid crystal display panel;

a timing controller for receiving compensated data, uncompensated data and synchronizing signals to output a gate control signal to the gate driver and to output both resultant data and a data control signal to the data driver;

a memory for storing information on a defect of the liquid crystal display panel;

a compensator for compensating a defect of the liquid crystal display panel based on the information from the memory and at least one synchronization signal; and

a multiplexer for selecting an output in accordance with whether the defect is a vertical line defect or a horizontal line defect to output a first compensated signal; and

a fine compensator that receives the first compensated signal and further compensates based on the first compensation signal being spatially and temporally distributed in accordance with a frame rate control dithering method, and outputs compensated data to the timing controller.

13. The video display device capable of compensating for display defects according to claim 12, wherein the fine compensator includes:

a frame determiner for counting pulses of a vertical synchronizing signal to detect a number of frames;

a pixel position determiner for determining pixel position information from the first compensated signal using at least one of the synchronizing signals;

a dither value selector for selecting dither values using the first compensated signal, the number of frames from the frame determiner, and the pixel position information output from the pixel position determiner; and

an adder for adding dither values from the dither value selector to the first compensated signal and then outputting resultant data.

14. The video display device capable of compensating for display defects according to claim 12, further comprising a point defect compensator that receives display data and compensates based on point defect information in the memory and outputs compensated data.

15. The video display device capable of compensating for display defects according to claim 14, wherein the point defect compensator includes:

a grayscale determiner for analyzing respective grayscale levels of the display data to be supplied to a link pixel of a point defect region, selecting grayscale range information corresponding to display data from the memory, and outputting a selected grayscale range information;

a position determiner for determining a pixel position from the display data using at least one of the synchronizing signals and outputting pixel information;

a compensation data selector for selecting compensation data output from memory base on the selected grayscale range information from the grayscale determiner and the pixel information from the position determiner; and

a calculator for one of adding and subtracting the compensation data output to the display data to output resultant data as compensated data.

16. The video display device capable of compensating for display defects according to claim 12, wherein each of the vertical and horizontal line compensators include:

a grayscale determiner for analyzing respective grayscale levels of the display data to be supplied to a link pixel of a point defect region, selecting grayscale range information corresponding to display data from the memory, and outputting a selected grayscale range information;

a position determiner for determining a pixel position from the display data using at least one of the synchronizing signals and outputting pixel information;

a compensation data selector for selecting compensation data output from memory base on the selected grayscale range information from the grayscale determiner and the pixel information from the position determiner;

an adder for adding the compensation data output to the display data to output resultant data;

a subtractor for subtracting the compensation data output from the display data to output resultant data;

a first multiplexer sequentially outputs the brightness information for typical defect regions in accordance with an order of the defect stored in the memory; and

a second multiplexer for selecting the output resultant data from one of the adder and the output resultant data from the subtractor in accordance with the brightness information and outputs the selected resultant data.

17. A video display device capable of compensating for display defects, comprising:

a liquid crystal panel for displaying an image through a pixel matrix;

a data driver for outputting data to data lines of the liquid crystal display panel;

a gate driver for driving the gate lines of the liquid crystal display panel;

a timing controller for receiving compensated data, uncompensated data and synchronizing signals to output a gate control signal to the gate driver and to output both resultant data and a data control signal to the data driver;

a memory for storing information on a defect of the liquid crystal display panel;

a grayscale determiner for analyzing respective grayscale levels of the display data to be supplied to a defect region, selecting grayscale range information corresponding to display data from the memory, and outputting a selected grayscale range information;

a position determiner for determining a pixel position from the display data and outputting pixel information;

a compensation data selector for selecting compensation data to be output from the memory based on the selected grayscale range information and the pixel information;

an adder for adding the compensation data output to the display data to output first resultant data;

a subtractor for subtracting the compensation data output from the display data to output second resultant data;

a first multiplexer for outputting brightness information in accordance with an order of the defect stored in the memory; and

a second multiplexer for selecting one of the first and second resultant data in accordance with the brightness information and outputting the selected resultant data as a compensated signal.

18. The video display device capable of compensating for display defects of claim 17, wherein the position determiner includes:

a first position determiner for determining a pixel position information of the display data in a horizontal direction;

a second position determiner for determining pixel position information of the display data in a vertical direction;

a multiplexer for selecting pixel position information from one of the first position determiner and the second position determiner in accordance with defect direction information from the memory.

19. The video display device capable of compensating for display defects according to claim 17, further comprising a fine compensator for receiving the compensated signal and further compensating based on the selected resultant data being spatially and temporally distributed in accordance with a frame rate control dithering method, and output compensated data.