Flat panel display having a compensation circuit to compensate a defective pixel

• US 7,990,356 B2
• Filed: 06/30/2006
• Issued: 08/02/2011
• Est. Priority Date: 12/02/2005
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Display Co., Ltd.
• Inventors: Lee, Deuk Su, Nam, Seung Hee, Hwang, Jong Hee, Chung, In Jae, Yoo, Soon Sung
• Primary Examiner(s): Shalwala; Bipin
• Assistant Examiner(s): CRAWLEY, KEITH L
• Application Number:
  US11/479,172
• Publication Number:
  US 20070126460A1
• Time in Patent Office: 1,859 Days
• Field of Search: 345 76- 83, 345 87-104, 324/770, 349/192, 349 54- 55
• US Class Current: 345/98
• 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 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence

Abstract

A flat panel display, a fabricating method thereof, a fabricating apparatus thereof, a picture quality controlling method thereof and a picture quality controlling apparatus for reducing a recognizing degree of a defective pixel and electrically compensating a charging characteristics of the defective pixel are provided.

In the flat panel display, a display panel has a plurality of pixels. A defective pixel is electrically connected to an adjacent normal pixel. A memory stores a location data that indicates a location of the link pixel and a compensation data that compensates for charging characteristics of the link pixel. A compensation circuit modulates a digital video data to be displayed on the link pixel on the basis of the location data and the compensation data.

Claims

1. A flat panel display, comprising:

a display panel that includes a plurality of data lines and a plurality of scan lines that cross each other;

a plurality of pixels, wherein a defective pixel is electrically connected to a normal pixel that is adjacent;

a plurality of switch devices formed at an area defined by an intersection between the data lines and the scan lines to supply a data signal from the data line to pixels that includes the link pixel;

a memory that stores a location data that indicates a location of a link pixel and a compensation data that compensates for a charging characteristics of the link pixel; and

a compensation circuit that modulates a input digital video data to be displayed on the link pixel on the basis of the location data and the compensation data,

wherein the link pixel includes the normal pixel adjacently with the defective pixel, the normal pixel displays the same color as a color displayed by the defective pixel,

wherein the compensation circuit compensates a charging characteristics of the link pixel on the basis of the location data stored in the memory, the compensation circuit varies a compensation data at the input digital video data corresponding to the location of the link pixel to modulate the input digital video data,

wherein the compensation circuit includes a location judging part, a gray scale level judging part, an address generator and a calculator,

wherein the calculator includes a multiplier or a divider which multiplies the charge compensation data to or divides the charging compensation data from the input digital video data other than an adder and a subtractor,

wherein the link pixel further includes a link pattern that overlaps with a first pixel electrode of the defective pixel and a second pixel electrode of the normal pixel adjacently with thereof with having a protective film therebetween,

wherein the link pattern is disposed on a pixel electrode of the defective pixel and a pixel electrode of the normal pixel having the same color adjacently with thereof,

wherein both edges of the link pattern overlap with the pixel electrodes of the defective and normal pixels adjacently in the vertical direction to directly connect to the pixel electrodes of the defective and normal pixels in a laser welding process, and

wherein the first and second pixel electrodes include an extending portion extended from the edge of an upper portion, and overlap with an edge of the link pattern by the extending portion.

2. The flat panel display as claimed in claim 1, wherein the location judging part judges the location of the input digital video data by using a synchronization signals, a data enable signal and a dot clock,

wherein the gray scale level judging part analyzes the gray scale level of the input digital video data,

wherein the address generator generates a read address that reads a charging compensation data of the location to supply to the memory if the location of the input digital video data corresponds to the normal pixel included in the link pixel by referring to the location data of the memory,

wherein the calculator adds the charging compensation data to or subtracts the charging compensation data from the input digital video data to modulate the input digital video data that is to be displayed in the normal pixel of the link pixel.

3. The flat panel display as claimed in claim 2, wherein the compensation data is set in accordance with the gray scale of a data to be displayed at the link pixel.

4. The flat panel display as claimed in claim 1, wherein a current path between the defective pixel and the switch device is shorted.

5. The flat panel display as claimed in claim 1, further comprising:

a data drive circuit that converts a digital video data modulated by the compensation circuit and a un-modulated digital video data into an analog data signal to supply to the data lines;

a scan drive circuit that supplies a scan signal to the scan lines;

the data drive circuit that supplies the digital video data to the data drive circuit; and

a timing controller controls the scan drive circuit.

6. The flat panel display as claimed in claim 5, wherein the compensation circuit is integrated within the timing controller.

7. The flat panel display as claimed in claim 1, wherein the memory includes EEPROM.

8. The flat panel display as claimed in claim 1, wherein the compensation circuit increases and decreases the compensation data into the input digital video data to be displayed at the link pixel.

9. The flat panel display as claimed in claim 1, wherein said display panel is either a display panel of a liquid crystal display device or a display panel of an organic light emitting diode.

10. The flat panel display as claimed in claim 1, wherein said memory includes EDID ROM.