Curved substrate bubble detection method and detection system

Patent metadata

Field	Value
Publication number	US-12480886-B2
Application number	US-202218023810-A
Country	US
Kind code	B2
Filing date	Mar 1, 2022
Priority date	Mar 1, 2022
Publication date	Nov 25, 2025
Grant date	Nov 25, 2025

Abstract

A curved substrate bubble detection method includes: providing, by a first light source and a second light source, parallel light incident to a to-be-tested substrate in different incident directions; obtaining, by a linear array camera, a first image including image information of a first side edge of the to-be-tested substrate; determining location information of a defect region of the to-be-tested substrate according to the first image, and generating a second image including image information of the defect region; binarizing the second image, and determining that the to-be-tested substrate has a bubble defect if there are at least two bright spots in an obtained binarized image, and a distance between any two first bright spots of at least two first bright spots is less than a first preset value. A curved substrate bubble detection system is also disclosed.

First claim

What is claimed is:

1 . A curved substrate bubble detection method, comprising:
providing, by a first light source and a second light source, parallel light incident to a to-be-tested substrate in different incident directions; obtaining, by a linear array camera, a first image comprising image information of a first side edge of the to-be-tested substrate, wherein the linear array camera is located in a transmission path of reflected light that is the parallel light provided by the first light source and specularly reflected off the to-be-tested substrate, and is located outside a transmission path of reflected light that is the parallel light provided by the second light source and specularly reflected off the to-be-tested substrate; determining location information of a defect region of the to-be-tested substrate according to the first image, and generating a second image comprising image information of the defect region; and binarizing the second image, and determining that the to-be-tested substrate has a bubble defect in case that there are at least two bright spots in an obtained binarized image, and a distance between any two first bright spots of at least two first bright spots is less than a first preset value, wherein the determining of the location information of the defect region of the to-be-tested substrate according to the first image, and the generating of the second image comprising image information of the defect region specifically comprise:
comparing brightness values of pixels in the first image with a first threshold value, adjusting the brightness value of any pixel whose brightness value is greater than the first threshold value to a first brightness value, and adjusting the brightness value of any pixel whose brightness value is less than the first threshold value to a second brightness value, wherein a location on the to-be-tested substrate corresponding to the pixel with the first brightness value is a location of the first side edge of the to-be-tested substrate, the first side edge comprising a straight portion and arc portions at two ends of the straight portion; and
selecting, with the location of the first side edge as a reference, a rectangular area in each of regions of an active display region of the to-be-tested substrate that are close to the arc portions respectively to obtain the second image.

2 . The curved substrate bubble detection method according to claim 1 , wherein the first image is a rectangular image, and has a length a in a first direction and a length b in a second direction, the first direction is an extending direction of the straight portion, and the second direction is perpendicular to the first direction;
the selecting, with the location of the first side edge as the reference, the rectangular area in each of regions of the active display region of the to-be-tested substrate that are close to the arc portions respectively to obtain the second image specifically comprises: establishing a coordinate system with the first direction being a y direction, the second direction being an x direction, and a vertex of the first image close to the first side edge being an origin; determining an intersection point (x, y) of an extension line of the straight portion and an extension line of a straight portion of a second side edge of the to-be-tested substrate according to the first side edge, and determining coordinates (x+x1, y) of a first vertex of the defect region according to the intersection point (x, y) and a distance x1 between the first side edge and the active display region; and selecting a rectangular area in the active display region of the to-be-tested substrate on the basis of the first vertex to obtain the second image, wherein a length of an edge of the rectangular area in a direction parallel to the first direction is a preset value y1, and a length of an edge of the rectangular area in the second direction is b−x−x1.

3 . The curved substrate bubble detection method according to claim 1 , wherein the binarizing the second image, and determining that the to-be-tested substrate has the bubble defect in case that there are at least two bright spots in the obtained binarized image, and a distance between any two first bright spots of the at least two first bright spots is less than the first preset value specifically comprise:
comparing brightness values of pixels in the second image with a second threshold value, adjusting the brightness value of any pixel whose brightness value is greater than the second threshold value to a third brightness value, and adjusting the brightness value of any pixel whose brightness value is less than the second threshold value to a fourth brightness value, a location corresponding to the pixel with the third brightness value being a location of the first bright spot; and
comparing a distance between two adjacent first bright spots with the first preset value, and determining that a location of the two adjacent first bright spots is a location of a bubble defect in case that the distance between the two adjacent first bright spots is less than the first preset value.

4 . The curved substrate bubble detection method according to claim 3 , wherein before comparing the distance between the two adjacent first bright spots with the first preset value, the method further comprises: screening the first bright spots for the first bright spot having a shape conforming to a bubble shape.

5 . The curved substrate bubble detection method according to claim 3 , wherein before comparing the brightness values of the pixels in the second image with the second threshold value, the method further comprises:
comparing the brightness values of the pixels in the second image with a third threshold value, adjusting the brightness value of any pixel whose brightness value is greater than the third threshold value to a fifth brightness value, and adjusting the brightness value of any pixel whose brightness value is less than the third threshold value to a sixth brightness value, a location corresponding to the pixel with the fifth brightness value being a location of a second bright spot, the third threshold value being less than the second threshold value; and determining that the second bright spot is a foreign matter defect in case that the second bright spot has a size greater than a second preset value, and has a shape not conforming to a bubble shape.

6 . The curved substrate bubble detection method according to claim 5 , wherein before comparing the brightness values of the pixels in the second image with the third threshold value, the method further comprises: filtering and dilating the second image.

7 . A curved substrate bubble detection system for implementing a curved substrate bubble detection method, wherein the curved substrate bubble detection method comprises:
providing, by a first light source and a second light source, parallel light incident to a to-be-tested substrate in different incident directions; obtaining, by a linear array camera, a first image comprising image information of a first side edge of the to-be-tested substrate, wherein the linear array camera is located in a transmission path of reflected light that is the parallel light provided by the first light source and specularly reflected off the to-be-tested substrate, and is located outside a transmission path of reflected light that is the parallel light provided by the second light source and specularly reflected off the to-be-tested substrate; determining location information of a defect region of the to-be-tested substrate according to the first image, and generating a second image comprising image information of the defect region; and binarizing the second image, and determining that the to-be-tested sub

Assignees

• Boe Technology Group Co Ltd
• Beijing Boe Technology Dev Co Ltd

Inventors

• Li Xing
• Li Ruize
• Tang Hao
• Lan Ronghua
• Cheng Jiuyang
• Guo Meng
• Yang Zhihui
• Zhang Qing
• Zhu Xuehui
• Zhou Quanguo
• Zhou Lijia
• Qiao Yong
• Huang Zhong
• Xu Lirong

Classifications

• G06T2207/30108

  Industrial image inspection · CPC title

• G06T7/0004

  Industrial image inspection · CPC title

• G01N2201/06146

  Multisources for homogeneisation, as well sequential as simultaneous operation · CPC title

• G01N2201/0438

  Linear motion, sequential · CPC title

• G01N2021/891

  Edge discrimination, e.g. by signal filtering · CPC title