ALIGNMENT METHOD BASED ON PIXEL COLOR AND ALIGNMENT SYSTEM FOR USING THE SAME

• US 20200135124A1
• Filed: 01/17/2018
• Published: 04/30/2020
• Est. Priority Date: 12/29/2017
• Status: Active Grant

• Current Assignee: Shenzhen China Star Optoelectronics Semiconductor Display Technology Co., Ltd.
• Original Assignee: Shenzhen China Star Optoelectronics Technology Co., Ltd. (TCL Technology Group Corp.)
• Inventors: YAN, Daobo
• Granted Patent: US 10,692,449 B2
• Time in Patent Office: Days
• CPC Class Codes: G02F 1/1303 Apparatus specially adapted to the manufacture of LCDs
• CPC Class Codes: G02F 1/1309 Repairing; Testing
• CPC Class Codes: G02F 1/133516 Methods for their manufacture, e.g. printing, electro-deposition or photolithography
• CPC Class Codes: G06T 2207/10024 Color image
• CPC Class Codes: G06T 2207/30121 CRT, LCD or plasma display
• CPC Class Codes: G06T 7/0004 Industrial image inspection
• CPC Class Codes: G06T 7/66 of image moments or centre of gravity
• CPC Class Codes: G06T 7/73 using feature-based methods
• CPC Class Codes: G06T 7/90 Determination of colour characteristics
• CPC Class Codes: G09G 2300/0443 with several sub-pixels for the same colour in a pixel, not specifically used to display gradations G09G3/364 takes precedence
• CPC Class Codes: G09G 2360/145 the light originating from the display screen
• CPC Class Codes: G09G 3/2003 Display of colours specific for liquid crystal displays G09G3/3607
• CPC Class Codes: G09G 3/3607 for displaying colours or for displaying grey scales with a specific pixel layout, e.g. using sub-pixels display of colours in flat matrix panels other than liquid crystal displays G09G3/2003; grey scales specific for television H04N3/127
• CPC Class Codes: G09G 3/3611 Control of matrices with row and column drivers

Abstract

An alignment method based on pixel color and an alignment system for using the same is disclosed. The method includes: Step S1: retrieving a photoresistance eigenvalue of each subcolor resist illuminated by a light source and setting a pixel threshold according to the photoresistance eigenvalue; Step S2: performing a binarization process on a pixel according to the pixel threshold to obtain a binary pixel; and Step S3: calculating an alignment position according to the binary pixel and aligning the color resist according to the alignment position. The present invention avoids the distribution of metal traces and patterns of a color filter on array (COA) product, improves the stability of measuring the COA product, aligns pixel with different shapes, and edits the computing logic for measured positions. When the shape of the pixel is irregular, the reasonable logic is selected to define the measured positions.

Claims

1. An alignment method based on pixel color, comprising:

Step S1;

retrieving a photoresistance eigenvalue of each subcolor resist illuminated by a light source and setting a pixel threshold according to the photoresistance eigenvalue;

Step S2;

performing a binarization process on a pixel according to the pixel threshold to obtain a binary pixel; and

Step S3;

calculating an alignment position according to the binary pixel and aligning the color resist according to the alignment position.

2. The alignment method based on pixel color according to claim 1, wherein the binarization process in Step S2 is a global fixed binarization process or a local adaptive binarization process.

3. The alignment method based on pixel color according to claim 2, wherein the global fixed binarization process comprises:

setting a gray level value of each pixel point of the pixel according to a pixel threshold T1 to 0 or 255;

when the pixel value of the pixel point is larger than the pixel threshold T1, the pixel value of the pixel point is set to 255; and

when the pixel value of the pixel point is not larger than the pixel threshold T1, the pixel value of the pixel point is set to 0.

4. The alignment method based on pixel color according to claim 2, wherein the local adaptive binarization process comprises:

calculating a pixel threshold T2 corresponding to a pixel point according to a local pixel characteristic of an aperture where the pixel point is located;

when the pixel value of the pixel point is larger than the pixel threshold T2, the pixel value of the pixel point is set to 255; and

when the pixel value of the pixel point is not larger than the pixel threshold T2, the pixel value of the pixel point is set to 0.

5. The alignment method based on pixel color according to claim 4, wherein the pixel threshold T2 of the local adaptive binarization process is expressed by T2=a*E+b*P+c*Q, wherein a, b, and c are free parameters, E is an average value of the pixel values of the aperture, P is a square of a difference between the pixel values, and Q is a mean effective value of the pixel values of the aperture.

6. The alignment method based on pixel color according to claim 1, wherein in Step S3 of calculating the alignment position according to the binary pixel, a position of a geometric centroid of the binary pixel is determined and used as the alignment position according to a shape of the binary pixel.

7. The alignment method based on pixel color according to claim 1, wherein the color resist is a red subcolor resist, a green subcolor resist, or a blue subcolor resist.

8. The alignment method based on pixel color according to claim 1, wherein the pixel threshold is set according to the photoresistance eigenvalue of the red subcolor resist.

9. The alignment method based on pixel color according to claim 6, wherein the binarization process in Step S2 is a global fixed binarization process or a local adaptive binarization process.

10. The alignment method based on pixel color according to claim 9, wherein the global fixed binarization process comprises:

setting a gray level value of each pixel point of the pixel according to a pixel threshold T1 to 0 or 255;

when the pixel value of the pixel point is larger than the pixel threshold T1, the pixel value of the pixel point is set to 255; and

when the pixel value of the pixel point is not larger than the pixel threshold T1, the pixel value of the pixel point is set to 0.

11. The alignment method based on pixel color according to claim 9, the local adaptive binarization process comprises:

calculating a pixel threshold T2 corresponding to the pixel point according to a local pixel characteristic of an aperture where the pixel point is located;

when the pixel value of the pixel point is larger than the pixel threshold T2, the pixel value of the pixel point is set to 255; and

when the pixel value of the pixel point is not larger than the pixel threshold T2, the pixel value of the pixel point is set to 0.

12. The alignment method based on pixel color according to claim 11, wherein the pixel threshold T2 of the local adaptive binarization process is expressed by T2=a*E+b*P+c*Q, wherein a, b, and c are free parameters, E is an average value of the pixel values of the aperture, P is a square of a difference between the pixel values, and Q is a mean effective value of the pixel values of the aperture.

13. An alignment system based on pixel color, comprising:

a threshold setting unit retrieving a photoresistance eigenvalue of each subcolor resist illuminated by a light source and setting a pixel threshold according to the photoresistance eigenvalue;

a pixel processing unit performing a binarization process on a pixel according to the pixel threshold to obtain a binary pixel; and

a positioning unit calculating an alignment position according to the binary pixel and aligning the color resist according to the alignment position.

14. The alignment system based on pixel color according to claim 13, wherein the pixel processing unit performs a global fixed binarization process or a local adaptive binarization process on the pixel according to the pixel threshold to obtain the binary pixel.