Apparatus for inspecting a display panel for defects

Patent metadata

Field	Value
Publication number	US-12046167-B2
Application number	US-201916512990-A
Country	US
Kind code	B2
Filing date	Jul 16, 2019
Priority date	Aug 30, 2018
Publication date	Jul 23, 2024
Grant date	Jul 23, 2024

Abstract

An apparatus for inspecting a display panel for defects includes a table which supports the display panel, a laser excitation unit that irradiates a non-display area of the display panel with a point laser beam, a thermal wave detecting unit that generates thermal wave images of irradiated portions of the non-display area, a driving unit, and a control unit. A groove corresponding to an edge of the display panel may be defined in a top surface of the table. A defect, such as a crack, may be detected by comparing a defect pattern obtained from the thermal wave images with a pre-registered defect pattern.

First claim

What is claimed is:

1. An apparatus for inspecting a display panel having an insulation pattern for detects after separating the display panel having the insulation pattern from a working panel, the apparatus comprising:
a table supporting the display panel after the separating the display panel having the insulation pattern from a working panel, the display panel including a display area on which a pixel is disposed and a non-display area on which the insulation pattern is disposed and disposed adjacent to the display area;
a laser excitation unit irradiating the non-display area of the display panel including portions of the non-display area having the insulation pattern with a point laser beam as the display panel is supported by the table;
a thermal wave detecting unit measuring a thermal wave generated from the non-display area based on the irradiation by the point laser beam as the display panel is supported by the table and generating a plurality of thermal wave images of portions of the non-display area irradiated by the point laser beam;
a driving unit modifying a position of the table; and
a control unit controlling an operation of each of the laser excitation unit, the thermal wave detecting unit, and the driving unit, the control unit detecting a crack in the insulation pattern by analyzing the plurality of thermal wave images,
wherein a body of the table includes a groove corresponding to an edge of the display panel defined in a top surface of the body of the table the groove distributes heat generated by the point laser beam to prevent damage to the display panel.

2. The apparatus of claim 1 , wherein the groove includes at least one linear area having a length of about 5 cm to about 30 cm and a width of about 700 μm to about 1300 μm.

3. The apparatus of claim 2 , wherein the non-display area has a width of about 500 μm to about 1500 μm.

4. The apparatus of claim 1 , wherein the groove has a closed-line shape in a plane view.

5. The apparatus of claim 1 , wherein the laser excitation unit comprises a laser emitter emitting the point laser beam and a focus lens controlling a focus of the point laser beam.

6. The apparatus of claim 1 , wherein the thermal wave detecting unit comprises a thermal imaging camera measuring the thermal wave and a macro lens controlling a photographing distance of the thermal imaging camera.

7. The apparatus of claim 1 , wherein an image of the point laser beam, which is formed on the display panel, has a diameter or a side having a length of about 150 μm to about 500 μm.

8. The apparatus of claim 1 , wherein the edge of the display panel comprises four areas, and the driving unit moves the table to irradiate the four areas of the edge with the point laser beam.

9. The apparatus of claim 1 , wherein the control unit detects a crack by:
comparing a match rate between at least one pre-registered first detect pattern comprising thermal wave images of a previously determined cracked portion and a second defect pattern acquired based on the plurality of thermal wave images, and
when the match rate is equal to or greater than a predetermined reference value, the second defect pattern is determined as a crack of the display panel.

10. The apparatus of claim 9 , wherein the control unit obtains the second defect pattern by:
extracting thermal wave imaging data having thermal variation;
generating an abnormal thermal wave image from the extracted thermal wave imaging data; and
obtaining the second defect pattern from the abnormal thermal wave image.

11. The apparatus of claim 9 , wherein the control unit registers the second defect pattern as a new first defect pattern if the match rate is equal to or greater than the reference value.

12. The apparatus of claim 1 , further comprising a suction pump,
wherein a suction hole extends from the top surface to a bottom surface or a side surface of the table, and
the suction pump suctions air through the suction hole to fix the display panel to the table.

13. The apparatus of claim 11 , wherein the suction hole is provided in plurality, and the plurality of suction holes are spaced a uniform distance from each other.

14. An apparatus for inspecting a display panel having an insulation pattern for detects after separating the display panel having the insulation pattern from a working panel, the apparatus comprising:
a table supporting the display panel after the separating the display panel having the insulation pattern from a working panel, the display panel including a display area on which a pixel is disposed and a non-display area on which the insulation pattern is disposed and disposed adjacent to the display area, wherein the table includes a suction hole extending from a top surface to a bottom surface or a side surface thereof;
a laser excitation unit irradiating the non-display area of the display panel including portions of the non-display area having the insulation pattern with a point laser beam as the display panel is supported by the table;
a thermal wave detecting unit measuring a thermal wave generated from the non-display area based on the irradiation by the point laser beam as the display panel is supported by the table and generating a plurality of thermal wave images of portions of the non-display area irradiated by the point laser beam;
a driving unit modifying a position of the table;
a suction pump suctioning air through the suction hole to fix the display panel to the table; and
a control unit controlling an operation of each of the laser excitation unit, the thermal wave detecting unit, the driving unit, and the suction pump, the control unit detecting a crack in the insulation pattern by analyzing the plurality of thermal wave images,
wherein a body of the table includes a groove corresponding to an edge of the display panel defined in a top surface of the body of the table, the groove distributes heat generated by the point laser beam to prevent damage to the display panel.

15. The apparatus of claim 14 , wherein the laser excitation unit comprises a laser emitter emitting the point laser beam and a focus lens controlling a focus of the point laser beam.

16. The apparatus of claim 14 , wherein the thermal wave detecting unit comprises a thermal imaging camera measuring the thermal wave and a macro lens controlling a photographing distance of the thermal imaging camera.

17. The apparatus of claim 14 , wherein an image of the point laser beam, which is formed on the display panel, has a diameter or a side having a length of about 150 μm to about 500 μm.

18. The apparatus of claim 14 , wherein an edge of the display panel comprises four areas, and the driving unit moves the table to irradiate the four areas of the edge with the point laser beam.

19. The apparatus of claim 14 , wherein the control unit detects a crack by:
comparing a match rate between at least one pre-registered first defect pattern comprising thermal wave images of a previously determined cracked portion and a second defect pattern acquired based on the plurality of thermal wave images, and
when the match rate is equal to or greater than a reference value, the second defect pattern is determined as a crack of the display panel.

20. The apparatus of claim 19 , wherein the control unit registers the second defect pattern as a new first detect pattern if the match rate is equal to or greater than the reference value.

21. The apparatus of claim 14 , wherein the suction hole is provided in plurality, and the plurali

Assignees

• Samsung Display Co Ltd
• Korea Advanced Inst Sci & Tech

Inventors

• Sohn Hoon
• Choi Sangwoo
• Koo Minsang
• Kwon Sanghyuk
• Shin Eunchul
• Jung Woojin
• Park Jiho
• Hwang Soonkyu

Classifications

• G01N21/171

  with calorimetric detection, e.g. with thermal lens detection · CPC title

• G01N25/72

  Investigating presence of flaws · CPC title

• G01N2021/95615

  with stored comparision signal · CPC title

• G01N21/95607

  using a comparative method · CPC title

• G01N2201/06113

  Coherent sources; lasers · CPC title