# US 12,217,415 B2 · Method of manufacturing a display device

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- Number: US 12,217,415 B2
- Document ID: US12217415B2
- Status: Granted
- Kind: B2
- Application number: 17/859,358
- Filed: 2022-07-07
- Published: 2023-03-30
- Granted: 2025-02-04
- Earliest claimed: 2021-09-29
- Assignees: Samsung Display Co., Ltd.
- Applicants: Samsung Display Co., Ltd.
- Inventors: Tae-Jin Hwang; Hyeongmin Ahn
- Web page: https://patentgrep.com/patent/US12217415B2

## CPC

- G06T 7/001: {using an image reference approach}
- G06T 5/50: using two or more images, e.g. averaging or subtraction
- G06T 5/70: Denoising; Smoothing
- G06T 5/80: Geometric correction
- G06F 3/041: Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
- G06F 2203/04103: Manufacturing, i.e. details related to manufacturing processes specially suited for touch sensitive devices
- G06T 2207/30121: CRT, LCD or plasma display
- G06T: IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
- G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N)

## Abstract

A method of manufacturing a display device includes preparing a cover substrate assembly including a cover substrate, a protective film attached to a lower surface of the cover substrate, and an inspection pattern disposed between the cover substrate and the protective film, obtaining a first image by imaging the inspection pattern through an upper surface of the cover substrate, obtaining noise data by comparing a reference image of the inspection pattern with the first image, obtaining a second image by imaging the cover substrate assembly, obtaining a corrected image of the second image by reflecting the noise data in the second image, and detecting a defect of the cover substrate based on the corrected image of the second image.

## Claims

### Claim 1

A method of manufacturing a display device, the method comprising:
preparing a cover substrate assembly including a cover substrate, a protective film attached to a lower surface of the cover substrate, and an inspection pattern disposed between the cover substrate and the protective film;
obtaining a first image by imaging the inspection pattern through an upper surface of the cover substrate;
obtaining noise data by comparing a reference image of the inspection pattern with the first image;
obtaining a second image by imaging the cover substrate assembly;
obtaining a corrected image of the second image by reflecting the noise data in the second image; and
detecting a defect of the cover substrate based on the corrected image of the second image.

### Claim 2 (depends on 1)

The method of claim 1, wherein the noise data comprises:
a value corresponding to a noise area difference which is a difference between a reference area of the inspection pattern in the reference image and an inspection area of the inspection pattern in the first image.

### Claim 3 (depends on 2)

The method of claim 2, wherein the obtaining the corrected image of the second image comprises:
obtaining an imaging defect area of the defect in the second image; and
obtaining the corrected image of the second image by reflecting the noise area difference in the imaging defect area.

### Claim 4 (depends on 3)

The method of claim 3, wherein the obtaining the corrected image of the second image by reflecting the noise area difference in the imaging defect area comprises:
comparing the imaging defect area and the inspection area; and
correcting the imaging defect area by reflecting the noise area difference when the imaging defect area is the same as the inspection area.

### Claim 5 (depends on 4)

The method of claim 4, wherein the obtaining the corrected image of the second image by reflecting the noise area difference in the imaging defect area further comprises:
obtaining an area correction value proportional to an area difference between the imaging defect area and the inspection area when the imaging defect area is different from the inspection area;
obtaining a corrected area difference by reflecting the area correction value to the noise area difference; and
correcting the imaging defect area by reflecting the corrected area difference.

### Claim 6 (depends on 3)

The method of claim 3, wherein the detecting the defect of the cover substrate based on the corrected image of the second image comprises:
obtaining a defect area of the defect;
comparing the defect area with a reference defect area; and
classifying the cover substrate as a defective cover substrate when the defect area is larger than the reference defect area.

### Claim 7 (depends on 2)

The method of claim 2, wherein the inspection pattern comprises:
first to nth size inspection patterns, each having different areas from each other, wherein n is a natural number equal to or greater than 2.

### Claim 8 (depends on 1)

The method of claim 1, wherein the noise data comprises:
a value corresponding to a noise grayscale difference which is a difference between a reference grayscale of the inspection pattern in the reference image and an imaging grayscale of the inspection pattern in the first image.

### Claim 9 (depends on 8)

The method of claim 8, wherein the obtaining the corrected image of the second image by reflecting the noise data in the second image comprises:
obtaining an imaging grayscale distribution of the cover substrate assembly from the second image; and
obtaining the corrected image of the second image having a corrected grayscale distribution by reflecting the noise grayscale difference in the imaging grayscale distribution.

### Claim 10 (depends on 9)

The method of claim 9, wherein the detecting the defect of the cover substrate based on the corrected image of the second image comprises:
comparing the corrected grayscale distribution with a normal grayscale range; and
classifying the cover substrate as a defective cover substrate when a grayscale defect having a grayscale outside the normal grayscale range is detected in the corrected grayscale distribution.

### Claim 11 (depends on 8)

The method of claim 8, wherein the inspection pattern comprises:
first to mth grayscale inspection patterns, each having different grayscales from each other, wherein m is a natural number equal to or greater than 2.

### Claim 12 (depends on 1)

The method of claim 1, further comprising:
removing the protective film and the inspection pattern from the cover substrate assembly when the defect is not detected after the detecting the defect of the cover substrate based on the corrected image of the second image; and
bonding a display panel including pixels under the cover substrate.

### Claim 13 (depends on 1)

The method of claim 1, wherein the cover substrate comprises:
a cover window; and
a touch sensing layer disposed under the cover window.

### Claim 14

A method of manufacturing a display device, the method comprising:
forming a cover substrate assembly by bonding a protective film to a lower surface of a cover substrate;
forming an inspection film by removing a portion of the protective film;
placing the inspection film over an inspection pattern provided on an upper surface of display panel;
obtaining a first image by imaging the inspection pattern through a lower surface of the display panel;
obtaining noise data by comparing a reference image of the inspection pattern with the first image;
obtaining a second image by imaging the cover substrate assembly;
obtaining a corrected image of the second image by reflecting the noise data in the second image; and
detecting a defect of the cover substrate based on the corrected image.

### Claim 15 (depends on 14)

The method of claim 14,
wherein the display panel comprises a display area and a peripheral area surrounding the display area, and
wherein the inspection pattern is disposed on the peripheral area.

### Claim 16 (depends on 15)

The method of claim 15,
wherein the cover substrate comprises a first area corresponding to the display area and a second area corresponding to the peripheral area, and
wherein the inspection film is formed by removing a portion of the protective film overlapping the second area.

### Claim 17 (depends on 14)

The method of claim 14, wherein the noise data comprises:
a value corresponding to a noise area difference which is a difference between a reference area of the inspection pattern in the reference image and an inspection area of the inspection pattern in the first image.

### Claim 18 (depends on 14)

The method of claim 14, wherein the noise data comprises:
a value corresponding to a noise grayscale difference which is a difference between a reference grayscale of the inspection pattern in the reference image and an imaging grayscale of the inspection pattern in the first image.

### Claim 19 (depends on 14)

The method of claim 14, further comprising:
removing the protective film from the cover substrate assembly when the defect is not detected after the detecting the defect of the cover substrate based on the corrected image of the second image; and
bonding a display panel under the cover substrate.

### Claim 20 (depends on 14)

The method of claim 14, wherein the cover substrate comprises:
a cover window; and
a touch sensing layer disposed under the cover window.
