CN111665260B - Display panel inspection device - Google Patents
Display panel inspection device Download PDFInfo
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- CN111665260B CN111665260B CN201911308754.2A CN201911308754A CN111665260B CN 111665260 B CN111665260 B CN 111665260B CN 201911308754 A CN201911308754 A CN 201911308754A CN 111665260 B CN111665260 B CN 111665260B
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- display panel
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/84—Systems specially adapted for particular applications
- G01N21/88—Investigating the presence of flaws or contamination
- G01N21/8851—Scan or image signal processing specially adapted therefor, e.g. for scan signal adjustment, for detecting different kinds of defects, for compensating for structures, markings, edges
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/84—Systems specially adapted for particular applications
- G01N21/88—Investigating the presence of flaws or contamination
- G01N21/95—Investigating the presence of flaws or contamination characterised by the material or shape of the object to be examined
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/84—Systems specially adapted for particular applications
- G01N21/88—Investigating the presence of flaws or contamination
- G01N21/8806—Specially adapted optical and illumination features
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/84—Systems specially adapted for particular applications
- G01N21/88—Investigating the presence of flaws or contamination
- G01N21/8851—Scan or image signal processing specially adapted therefor, e.g. for scan signal adjustment, for detecting different kinds of defects, for compensating for structures, markings, edges
- G01N2021/8887—Scan or image signal processing specially adapted therefor, e.g. for scan signal adjustment, for detecting different kinds of defects, for compensating for structures, markings, edges based on image processing techniques
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/84—Systems specially adapted for particular applications
- G01N21/88—Investigating the presence of flaws or contamination
- G01N21/95—Investigating the presence of flaws or contamination characterised by the material or shape of the object to be examined
- G01N2021/9513—Liquid crystal panels
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2201/00—Features of devices classified in G01N21/00
- G01N2201/06—Illumination; Optics
- G01N2201/063—Illuminating optical parts
- G01N2201/0636—Reflectors
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- Physics & Mathematics (AREA)
- Chemical & Material Sciences (AREA)
- Pathology (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Life Sciences & Earth Sciences (AREA)
- Health & Medical Sciences (AREA)
- Engineering & Computer Science (AREA)
- Computer Vision & Pattern Recognition (AREA)
- Signal Processing (AREA)
- Investigating Materials By The Use Of Optical Means Adapted For Particular Applications (AREA)
- Electroluminescent Light Sources (AREA)
- Devices For Indicating Variable Information By Combining Individual Elements (AREA)
- Testing Of Optical Devices Or Fibers (AREA)
Abstract
The present invention relates to a display panel inspection apparatus. The display generates a periodic reference pattern, and irradiates the surface of the display panel as an inspection object with an incident angle larger than the critical angle for total reflection. The camera acquires an image reflected from the display panel surface in a state in which the reference pattern is irradiated to the display panel surface. The controller sequentially acquires images through the camera while shifting the reference pattern by a predetermined angle each time in one period through the display, and then calculates a phase and an inclination for the display panel surface based on the acquired images, thereby discriminating whether the display panel surface is defective.
Description
Technical Field
The present invention relates to a display panel inspection apparatus, and more particularly, to an apparatus for inspecting an appearance defect of a display panel.
Background
In general, display panels are widely used in smartphones, notebook computers, televisions, computer monitors, and the like. Such display panels include LCD (Liquid Crystal Display ) panels, OLED (Organic Light Emitting Diode, organic light emitting diode) panels, and the like.
On the other hand, appearance defects such as scratches (scratch), cracks (chip), chipping (chipping), and the like may occur at the surface of the display panel during the production of the display panel. In particular, the OLED panel is composed of a flexible substrate, and has low hardness, so that appearance defects such as dents (dents) may occur even when the surface is pressed. Therefore, a process for inspecting an appearance defect of the display panel is performed at a production site of the display panel.
However, in the past, the technician visually inspected the sample, and in this case, there were the following problems: since personal differences in proficiency of the staff, etc., reduce the reliability of checking defects, and the staff intensively works for a long time to check defects, eye fatigue is caused, thus reducing productivity.
Disclosure of Invention
(problems to be solved)
The invention provides a display panel inspection device which can automate the detection of appearance defects of a display panel, improve the productivity and improve the reliability of detecting the defects.
(means for solving the problems)
The display panel inspection device of the present invention for achieving the above object comprises: display, camera and controller. The display generates a periodic reference pattern, and irradiates the surface of the display panel as an inspection object with an incident angle larger than the critical angle for total reflection. The camera acquires an image reflected from the display panel surface in a state in which the reference pattern is irradiated to the display panel surface. The controller sequentially acquires images through the camera while shifting the reference pattern by a predetermined angle every time in one period through the display, and then calculates a phase and an inclination for the display panel surface based on the acquired images, thereby discriminating whether the display panel surface is defective.
Here, the controller sequentially acquires four images through the camera while shifting the reference pattern by 90 ° each time through the display.
Then, the display panel inspection device includes a mirror that receives light reflected from the surface of the display panel and reflects the light to the camera. The camera may be configured to receive light reflected by the mirror.
(effects of the invention)
The invention can automatically detect the appearance defects of the display panel, and has the effects of improving the productivity and improving the reliability of detecting the defects.
Drawings
Fig. 1 is a structural diagram of a display panel inspection apparatus according to an embodiment of the present invention.
Fig. 2 is a block diagram showing a part of the display panel inspection apparatus of fig. 1.
Fig. 3 is a perspective view of fig. 2.
Fig. 4 is a photograph showing an example of images sequentially acquired while shifting the reference pattern by 90 ° each time.
Fig. 5 is a photograph showing a phase image and an inclination image obtained based on the image of fig. 4.
(description of the reference numerals)
10: display panel
110: display device
111: reference pattern
120: camera head
140: mirror
130: controller for controlling a power supply
Detailed Description
The present invention is described in detail below with reference to the accompanying drawings. The same reference numerals are used for the same components, and detailed descriptions of known functions and configurations that make the gist of the present invention unclear are omitted. Embodiments of the present invention are provided to more fully inform those having ordinary skill in the art of the present invention. Accordingly, the shape, size, etc. of the members may be exaggerated in the drawings for the sake of more clear explanation.
Fig. 1 is a structural diagram of a display panel inspection apparatus according to an embodiment of the present invention. Fig. 2 is a block diagram showing a part of the display panel inspection apparatus of fig. 1. Fig. 3 is a perspective view of fig. 2.
Referring to fig. 1 to 3, a display panel inspection apparatus 100 according to an embodiment of the present invention includes: a display 110, a camera 120, and a controller 130.
The display 110 generates a periodic reference pattern 111 to be irradiated on the surface of the display panel 10 to be inspected. Here, the display panel 10 may be an OLED panel, but may also be an LCD panel or the like. In the case where the display panel 10 is mounted on the XY level of the inspection stage 101 in a state where the surface to be inspected is directed upward, the display 110 may be configured to irradiate the reference pattern 111 at a set incident angle on the upper side of the display panel 10. The inspection station 101 may be fixed and supported to the inspection frame 102 and the display 110 may be fixed and supported to the inspection frame 102.
The reference pattern 111 may be formed in a form in which relatively bright bands and relatively dark bands are alternately arranged. The bright and dark bands have predetermined periods, respectively. The display 110 is constituted by a flat display device such as an LCD device or an OLED device, and further irradiates the reference pattern 111 to the entire surface of the display panel 10 in the form of a surface light source. The display 110 is controlled by the controller 130 to phase-shift the reference pattern 111 by a predetermined angle each time in one cycle when performing an appearance inspection of the surface of the display panel 10.
The display panel 10 is configured to transmit light through the surface, and thus it is necessary that the reference pattern 111 incident on the surface of the display panel 10 from the display 110 is provided to the camera 120 by total reflection. For this, the display 110 irradiates the reference pattern 111 to the surface of the display panel 10 at an incident angle α greater than the critical angle for total reflection. The larger the incident angle α of the reference pattern 111, the better the total reflection of the reference pattern 111 can be achieved, but the Footprint (Footprint) of the display panel inspection apparatus 100 increases. If the display panel 10 is an OLED panel, the incident angle α of the reference pattern 111 may be set to 55 to 57 °.
The camera 120 acquires an image reflected from the surface of the display panel 10 in a state where the reference pattern 111 is irradiated on the surface of the display panel 10. If the reference pattern 111 is irradiated on the surface of the display panel 10, the reference pattern 111 may be deformed by the influence of the surface shape of the display panel 10. The camera 120 acquires an image of the deformed reference pattern, and thus the surface shape of the display panel 10 can be reversely obtained.
The camera 120 may be constituted by a CCD camera (charge-coupled device camera) or the like. A CCD camera is a device that converts an image into an electric signal using a Charge Coupled Device (CCD). The camera 120 may receive light reflected from the surface of the display panel 10 through a lens.
The camera 120 may be disposed at one side of the display panel 10 together with the display 110 to minimize the footprint of the display panel inspection device 100. For example, if the display 110 is disposed on the left side of the display panel 10, the camera 120 may be disposed higher than the display 100 on the left side of the display panel 10. In this case, the light received by the mirror 140 reflected from the surface of the display panel 10 may be reflected to the camera 120.
The mirror 140 is disposed at the opposite side of the display 110, and the display panel 10 is disposed between the mirror 140 and the display 110. The mirror 140 can be vertically erected with its reflection surface facing the display 110. The mirror 140 may be fixed and supported on the inspection frame 102. The camera 120 may be configured to receive light reflected by the mirror 140. The camera 120 may be fixed to the inspection frame 102 by a bracket or the like in a state where the light receiving axis is inclined at a set angle β to the horizontal plane. If the incident angle α of the reference pattern 111 is 56 °, the light receiving axis angle β of the camera 120 may be 34 °.
The controller 130 sequentially acquires images through the camera 120 while shifting the reference pattern 111 by a predetermined angle each time in one period through the display 110, and then calculates a phase shift and an inclination for the surface of the display panel 10 based on the acquired images, thereby discriminating whether the surface of the display panel 10 is defective.
If appearance defects such as scratches, cracks, breaks, etc. exist on the surface of the display panel 10, appearance defect regions may occur in the phase image and the inclination image which are calculated by the controller 130. The controller 130 processes the phase image and the inclination image to distinguish whether the surface of the display panel 10 is defective.
For example, the controller 130 may detect the appearance defect region using a labeling (labeling) technique for the phase image and the inclination image. The labeling is a method of distinguishing each object by numbering all pixels of the search image using a connection relationship of four-connected (4-connected) or eight-connected (8-connected) or the like.
The controller 130 distinguishes between the background area and the appearance defect area based on the phase image data and the inclination data obtained by the labeling, by which the appearance defect area can be detected. If the appearance defect area is detected, the controller 130 determines that the surface of the display panel 10 is defective. At this time, if the appearance defect region is detected from both the phase image data AND the inclination image data by the AND calculation, the controller 130 may determine that a defect exists on the surface of the display panel 10. The controller 130 may be composed of at least one program of executable control programs.
On the other hand, the controller 130 may sequentially acquire four images through the camera 120 while shifting the reference pattern 111 by 90 ° each time through the display 110. For example, in the case where the controller 130 sequentially acquires four images through the camera 120 while shifting the reference pattern 111 by 90 ° each time through the display 110, the brightness values of the four images are as shown in the following equation 1:
(mathematics 1)
I 1 (x，y)＝I 0 (x，y){1+γ(x，y)cos[φ(x，y)]}
I 3 (x，y)＝I 0 (x，y){1+γ(x，y)cos[φ(x，y)+π]}
Here, x, y is a space variable (spatial variables). I 0 (x, y) is the average luminance value of the reference pattern. Visibility (visibility) of the gamma (x, y) reference pattern. Phi (x, y) is the phase value to be measured. The reference pattern is shifted by about δ, i.e. 90 °, per reference pattern.
I as luminance values of the four images shown in the above formula 1 by calculation transformation of trigonometric function equivalent values 1 (x，y),I 2 (x，y),I 3 (x，y),I 4 (x, y), and then solving the simultaneous equation, the phase phi (x, y) of each point of the display panel surface can be found as in the following equation 2:
(mathematics 2)
The inclination can be obtained by substituting the phase Φ (x, y) obtained as described above into the following equation 3 indicating the relationship between the phase and the inclination:
(mathematics 3)
Here the number of the elements to be processed is,the x-axis and y-axis inclinations of the local positions (i, j), respectively, h being the data interval and N being the number of data.
For example, in the case where the surface of the display panel 10 has an appearance defect, if the controller 130 sequentially acquires four images through the camera 120 while shifting the reference pattern 111 by 90 ° each time through the display 110, the acquired images may be as shown in (a), (b), (c), and (d) of fig. 4.
If the controller 130 calculates the phase and the inclination with respect to the surface of the display panel 10 based on the acquired image, the phase image may be obtained as in fig. 5 (a) and the inclination image may be obtained as in fig. 5 (b). As shown in fig. 5 (a) and (b), it was confirmed that a defective region (DZ) appears in the phase image and the gradient image. The controller 130 processes the phase image and the inclination image as in the above example to distinguish whether the surface of the display panel 10 is defective.
As described above, with the display panel inspection apparatus 100 of the present embodiment, the appearance defect detection of the display panel 10 is automated, the productivity can be improved, and the reliability of detecting defects can be improved.
The invention has been described with reference to one embodiment shown in the drawings, but this is merely exemplary, and it is to be understood that a person having ordinary skill in the art may implement various modifications and equivalent other embodiments therefrom. Therefore, the true scope of the invention should be defined only by the claims.
Claims (3)
1. A display panel inspection apparatus comprising:
a display for generating a periodic reference pattern, and irradiating the surface of a display panel as an inspection object with an incident angle larger than a critical angle of total reflection;
a camera that acquires an image reflected from the surface of the display panel in a state in which a reference pattern is irradiated to the surface of the display panel; a kind of electronic device with high-pressure air-conditioning system
A controller sequentially acquiring images through the camera while shifting the reference pattern by a predetermined angle each time in one period through the display, and then calculating a phase Φ (x, y) and an inclination for the display panel surface based on the acquired images to distinguish a background area and an appearance defect area, thereby distinguishing whether the display panel surface is defective; wherein the controller determines that a defect exists on the surface of the display panel if an appearance defect region is detected from both the phase and the inclination;
the inclination is obtained by the following formula:
wherein the method comprises the steps ofThe x-axis and y-axis inclinations of the local positions (i, j), respectively, h being the data interval and N being the number of data.
2. The display panel inspection apparatus according to claim 1, wherein,
the controller sequentially acquires four images through the camera while shifting the reference pattern by 90 degrees each time through the display.
3. The display panel inspection apparatus according to claim 1, comprising:
and a mirror receiving light reflected from the surface of the display panel and reflecting the light to the camera.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR1020190026492A KR102199314B1 (en) | 2019-03-07 | 2019-03-07 | Apparatus for inspecting display panel |
| KR10-2019-0026492 | 2019-03-07 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN111665260A CN111665260A (en) | 2020-09-15 |
| CN111665260B true CN111665260B (en) | 2023-10-03 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN201911308754.2A Active CN111665260B (en) | 2019-03-07 | 2019-12-18 | Display panel inspection device |
Country Status (3)
| Country | Link |
|---|---|
| KR (1) | KR102199314B1 (en) |
| CN (1) | CN111665260B (en) |
| TW (1) | TWI719784B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20220118807A (en) * | 2021-02-19 | 2022-08-26 | 삼성전자주식회사 | Electronic device and control method thereof for detecting surface defect of test device |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20110087551A (en) * | 2010-01-26 | 2011-08-03 | 주식회사 고영테크놀러지 | Image sensing system and method |
| CN102169095A (en) * | 2009-09-24 | 2011-08-31 | 凯德易株式会社 | Inspecting system and inspecting method |
| JP2014020870A (en) * | 2012-07-17 | 2014-02-03 | Kurabo Ind Ltd | Surface shape inspection device and surface shape inspection method |
| TW201741779A (en) * | 2016-03-01 | 2017-12-01 | Ａｓｍｌ荷蘭公司 | Method and apparatus to determine a patterning process parameter |
| CN109791088A (en) * | 2016-12-15 | 2019-05-21 | 欧姆龙株式会社 | Check device, inspection method and program |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4645068B2 (en) * | 2004-06-04 | 2011-03-09 | 旭硝子株式会社 | Surface shape inspection method and inspection apparatus |
| KR100870131B1 (en) * | 2007-04-04 | 2008-11-25 | 한국과학기술원 | Apparatus and method for simultaneous measurement of critical and surface plasmon resonance angle |
| JP2009092426A (en) * | 2007-10-04 | 2009-04-30 | Nippon Steel Corp | Surface inspection method and surface inspection device |
| KR101798219B1 (en) * | 2015-06-24 | 2017-11-15 | 연세대학교 산학협력단 | Imaging Device and Method for Obtaining Multi Contrast Images |
| JP6584454B2 (en) * | 2017-06-14 | 2019-10-02 | キヤノン株式会社 | Image processing apparatus and method |
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2019
- 2019-03-07 KR KR1020190026492A patent/KR102199314B1/en active IP Right Grant
- 2019-12-18 CN CN201911308754.2A patent/CN111665260B/en active Active
- 2019-12-27 TW TW108148173A patent/TWI719784B/en active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102169095A (en) * | 2009-09-24 | 2011-08-31 | 凯德易株式会社 | Inspecting system and inspecting method |
| KR20110087551A (en) * | 2010-01-26 | 2011-08-03 | 주식회사 고영테크놀러지 | Image sensing system and method |
| JP2014020870A (en) * | 2012-07-17 | 2014-02-03 | Kurabo Ind Ltd | Surface shape inspection device and surface shape inspection method |
| TW201741779A (en) * | 2016-03-01 | 2017-12-01 | Ａｓｍｌ荷蘭公司 | Method and apparatus to determine a patterning process parameter |
| CN109791088A (en) * | 2016-12-15 | 2019-05-21 | 欧姆龙株式会社 | Check device, inspection method and program |
Also Published As
| Publication number | Publication date |
|---|---|
| CN111665260A (en) | 2020-09-15 |
| KR102199314B1 (en) | 2021-01-06 |
| TW202033955A (en) | 2020-09-16 |
| TWI719784B (en) | 2021-02-21 |
| KR20200107404A (en) | 2020-09-16 |
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