KR20090006456A - Apparatus for inspecting liquid crystal display panel and method for inspecting it - Google Patents

Apparatus for inspecting liquid crystal display panel and method for inspecting it Download PDF

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Publication number
KR20090006456A
KR20090006456A KR1020070069819A KR20070069819A KR20090006456A KR 20090006456 A KR20090006456 A KR 20090006456A KR 1020070069819 A KR1020070069819 A KR 1020070069819A KR 20070069819 A KR20070069819 A KR 20070069819A KR 20090006456 A KR20090006456 A KR 20090006456A
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South Korea
Prior art keywords
liquid crystal
crystal panel
image
pattern
light
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Application number
KR1020070069819A
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Korean (ko)
Inventor
정재영
Original Assignee
엘지디스플레이 주식회사
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Priority to KR1020070069819A priority Critical patent/KR20090006456A/en
Publication of KR20090006456A publication Critical patent/KR20090006456A/en

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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
    • G01N21/89—Investigating the presence of flaws or contamination in moving material, e.g. running paper or textiles
    • G01N21/892—Investigating the presence of flaws or contamination in moving material, e.g. running paper or textiles characterised by the flaw, defect or object feature examined
    • G01N21/896—Optical defects in or on transparent materials, e.g. distortion, surface flaws in conveyed flat sheet or rod
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/1306—Details
    • G02F1/1309—Repairing; Testing
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/006—Electronic inspection or testing of displays and display drivers, e.g. of LED or LCD displays

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  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • General Physics & Mathematics (AREA)
  • Chemical & Material Sciences (AREA)
  • Nonlinear Science (AREA)
  • Optics & Photonics (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Theoretical Computer Science (AREA)
  • Computer Hardware Design (AREA)
  • Textile Engineering (AREA)
  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Biochemistry (AREA)
  • General Health & Medical Sciences (AREA)
  • Immunology (AREA)
  • Pathology (AREA)
  • Liquid Crystal (AREA)

Abstract

An apparatus for inspecting a liquid crystal display panel is provided to reduce the production yield of a liquid crystal panel by reducing over detecting rate. A liquid crystal panel is loaded in a probe(S101). The probe device is operated and voltage is applied at the liquid crystal panel(S102). A camera positioned at the upper of the liquid crystal panel is operated and the liquid crystal panel is taken a picture of. A first image of the liquid crystal panel is taken and it stores(S103). The power source of probe is turned off. A light generating apparatus positioned at the upper of the liquid crystal panel is operated and the light is provided on the liquid crystal panel(S104). The camera positioned at the upper of the liquid crystal panel is operated and the liquid crystal panel is taken a picture of. The second image including outside defective pattern is acquired and it stores(S105). The first image and the second image are compared and it is analyzed and the internal defect pattern of the liquid crystal panel is drawn(S106-S108).

Description

Liquid crystal panel inspection device and inspection method {APPARATUS FOR INSPECTING LIQUID CRYSTAL DISPLAY PANEL AND METHOD FOR INSPECTING IT}

The present invention relates to a liquid crystal panel inspection device and an inspection method of a liquid crystal display device, and more particularly, mura, point defects and line defects generated inside the liquid crystal panel during vision inspection of the liquid crystal panel. defect) and foreign matter defects caused by external factors such as dust on the liquid crystal panel, and related to the liquid crystal panel inspection apparatus and inspection method for reducing defects and detection of the liquid crystal panel.

In general, a liquid crystal display (LCD) realizes an image by adjusting light transmittance of liquid crystal cells arranged in a matrix form on a liquid crystal panel with a data signal supplied thereto. To this end, the liquid crystal display includes an electrode for applying an electric field to the liquid crystal layer, a thin film transistor (TFT) for switching data supply for each liquid crystal cell, and externally supplied data to the liquid crystal cells. Signal wiring for supplying, signal wiring for supplying a control signal of the TFT, and the like.

Such LCDs include the manufacturing process of the upper and lower plates of the liquid crystal panel, the formation and rubbing processes of the alignment layer for liquid crystal alignment, and the bonding process of the upper and lower plates. The process is completed through various processes such as a process of injecting and encapsulating a liquid crystal between the upper and lower plates.

Here, the manufacturing process of the lower plate includes the formation of TFTs and the formation of other electrode portions through the application and etching of electrode materials, semiconductor layers and insulating films on the substrate. In addition, after the liquid crystal injection and encapsulation process, the polarizing plate is attached to both sides of the upper and lower plates, and the final inspection operation is performed when the liquid crystal panel is completed.

Hereinafter, with reference to the drawings will be described in more detail with respect to the manufacturing process of the liquid crystal panel.

1 is a flowchart illustrating a manufacturing process of a liquid crystal panel according to the related art.

As shown in FIG. 1, first, a thin film transistor array substrate on which a gate line and a data line are formed to cross each other and a thin film transistor is formed on the intersection region and a color filter substrate on which a color filter are formed are bonded (S11).

At this time, the bonding of the two substrates is made of a plurality of color filter substrates bonded to each other on a large array substrate, or a color filter substrate smaller than the array substrate bonded to each other on the array substrate of a separate unit. Also, at least one side of the array substrate is formed with a contact pattern for performing a VAP (Vision Auto Probe) on a plurality of liquid crystal panels or a unit liquid crystal panel, thereby collectively or individually driving the liquid crystal panel. It becomes possible.

Then, a VAP step is performed (S12). Of course, this process uses an automatic inspection equipment, which includes an autoprobe device for contacting the liquid crystal panel and inputting an inspection pattern into the liquid crystal panel, and collecting patterns appearing on the liquid crystal panel installed on the upper side of the liquid crystal panel. It includes a computer system for analyzing and determining the information of the vision unit and the collected pattern.

The autoprobe device includes a gate and data needle for electrical connection to a gate line and a data line on the liquid crystal panel. In other words, prior to connecting the driving circuit for driving the liquid crystal panel by connecting to the plurality of gate lines and data lines in the module process, a voltage is optionally applied to the gate needle and the data needle to inspect the external appearance and electrical defect of the panel. To do.

In addition, the vision unit is provided with a camera for detecting a pattern to analyze the signal input to the camera. That is, it is located on the top of the auto probe device to collect the pattern displayed on the panel through the scan in the horizontal direction.

The computer system receives information from the camera and analyzes and determines whether a pattern is properly output.

When the bulk or individual VAP of the liquid crystal panel as described above is finished (S13). That is, a plurality of liquid crystal panels are scribed into individual units. The scribing is performed by cutting each TFT array by a cutting mechanism such as, for example, a diamond wheel, to scribe one liquid crystal panel. Bing In this case, the diamond wheel scribes the array substrate and the color filter substrate along the scribing line.

Then, the grinding of the individual liquid crystal panel is performed (S14). In other words, the edges of the array substrate and the color filter substrate constituting the liquid crystal panel are polished to improve the resistance to breakage.

Subsequently, a visual step (Auto Probe) is made (S15). In this case, it is possible to determine a poor polishing or a mura through a simple visual inspection of all the unit liquid crystal panels.

Then, the shipping step is performed (S16). This means that the work procedure is transferred to the module process, and the liquid crystal display device is completed through a series of processes.

In recent years, in the above-described configuration, as the resolution of the liquid crystal panel increases, the role of the vision unit for performing the VAP step has been increased, and thus, the camera used for the vision unit has been used for high resolution.

At this time, the high resolution camera of the vision unit detects the foreign matters such as dust and the like on the liquid crystal panel, including point defects and line defects when the pattern of the liquid crystal panel is detected, thereby increasing the defective rate of the liquid crystal panel. Yield was reduced.

The present invention has been made to solve the above problems, and an object thereof is to provide an inspection apparatus and an inspection method of a liquid crystal panel to reduce the defect and detection rate of the liquid crystal panel when detecting the pattern of the liquid crystal panel.

The liquid crystal panel inspection apparatus according to the present invention for achieving the above object comprises a probe device for applying a voltage to the liquid crystal panel by loading the liquid crystal panel; A light generating device provided above the liquid crystal panel to provide light on the liquid crystal panel; After the voltage is applied through the probe device, the first image is obtained by photographing the pattern appearing on the liquid crystal panel, and after the light is provided to the liquid crystal panel from the light generating device, the liquid crystal panel is photographed. A vision unit for acquiring two images; And a control unit for comparing and analyzing the first image and the second image of the liquid crystal panel acquired in association with the vision unit.

In addition, the liquid crystal panel inspection method according to the present invention includes the steps of loading the liquid crystal panel in the probe device; Operating the probe device to apply a voltage to the liquid crystal panel; Photographing the liquid crystal panel by operating a camera positioned above the liquid crystal panel, acquiring and storing a first image including an internal defect pattern of the liquid crystal panel and an external defect pattern caused by foreign matter; Turning off a power supply of the probe device and operating a light generating device positioned above the liquid crystal panel to provide light on the liquid crystal panel; Photographing the liquid crystal panel by operating a camera positioned above the liquid crystal panel, acquiring and storing a second image including an external defect pattern; And deriving an internal defect pattern of the liquid crystal panel by comparing and analyzing the first image and the second image.

As a result of the above configuration, the liquid crystal panel inspection apparatus and the inspection method according to the present invention can reduce the yield reduction of the liquid crystal panel by reducing the defective over-detection rate that can be caused by applying a high-resolution camera when inspecting the defect pattern of the liquid crystal panel.

Hereinafter, the configuration will be described in detail with reference to the accompanying drawings.

2 is a view showing a liquid crystal panel inspection device according to the present invention.

As shown in FIG. 2, a support member 200 is provided at an inner lower end of the inspection apparatus according to the present invention, in which a probe device 300 is contacted with the liquid crystal panel 400. In addition, the support member 200 is provided with a driving device (not shown) for loading and unloading the liquid crystal panel 400 into the probe device 300 to drive the vehicle forward, backward, leftward, or rightward.

In this case, the probe device 300 applies a voltage to the gate needle 310 and the data needle 320 arbitrarily before proceeding with the module process of the liquid crystal panel 400 to inspect the appearance and electrical failure of the unit panel. In this case, the pads of the liquid crystal panel 400 and the gate line (not shown) and the data line (not shown) must be accurately contacted. To this end, the probe device 300 includes a gate needle 310 and a data needle 320 for electrical connection to the gate line and the data line of each unit panel. The probe device 300 includes a backlight device including a lamp to provide light to the liquid crystal panel 400.

In addition, a light generator 700 for providing light to the liquid crystal panel 400 loaded on the probe device 300 is provided above the support member 200 and the probe device 300. In this case, when light is provided on the liquid crystal panel 400 through the light generating device 700, the light shows a difference in luminance different from the surrounding area at a portion where a foreign material or the like exists.

The light generating apparatus 700 may further include a grating means such as a mask coated with chromium (Cr) or the like, in addition to the light projector. When the light generating apparatus 700 scans the lattice pattern on the liquid crystal panel 400 using a white light to monochromatic light projector, the lattice of light or shadow of the lattice pattern draped on a foreign material or the like on the liquid crystal panel 400. The line is distorted, or the area where the foreign material exists and the surrounding area show different luminance differences.

In addition, the camera 600 is mounted to be spaced apart from the light generating device 700 by a predetermined interval. In this case, the camera 600 provides a first image by photographing a pattern that appears after voltage is applied to the liquid crystal panel 400 loaded on the probe device 300, and provides a voltage applied to the liquid crystal panel 400. At the same time, the light is supplied from the upper light generating device 700 to the liquid crystal panel 400 to photograph the liquid crystal panel 400 showing the difference in luminance due to a foreign material and provide a second image. charge coupled device) An optical camera is used.

In addition, in conjunction with the camera 600, a computer device 800 including a control unit is installed. Such a computer device 800 is fastened to the liquid crystal panel inspection apparatus 100 and positioned outside thereof, or may be installed separately from the inspection apparatus 100.

The computer device 800 analyzes information obtained by photographing an internal pattern in the liquid crystal panel 400 or a foreign material on the liquid crystal panel 400 from the camera 600 to determine defect patterns and location information of the foreign material. By comparing the two positional information of the defect pattern and the foreign material by coordinate analysis, the actual defect pattern such as point defects or line defects in the liquid crystal panel 400 is detected.

3 is a flowchart illustrating an inspection method using the inspection apparatus of FIG. 2.

2 and 3, the liquid crystal panel 400 is loaded on the probe device 300 provided on the support member 200 in the inspection apparatus (S101). At this time, the liquid crystal panel 400 will be transferred by the driving device provided in the support member 200 as mentioned above.

After the liquid crystal panel 400 is loaded in this manner, the lower probe device 300 is operated to apply a voltage to the liquid crystal panel 400 (S102).

Then, the camera 600 positioned above the liquid crystal panel 400 is operated to photograph the pattern appearing on the liquid crystal panel 400 (S103). In this case, the camera 600 includes spot defects, line defects, and unevenness, which are defects in the fixed form formed in the liquid crystal panel 400, and foreign matter containing dust that is indeterminate defects on the liquid crystal panel 400. The first information (or first image), which is acquired together with the image pattern and the like and all recognized as a defect, is transmitted to the computer device 800.

Subsequently, after the power of the liquid crystal panel 400 loaded on the probe device 300 is turned off, the operation of operating the light generating device 700 positioned above the liquid crystal panel 400 is performed (S104). In this case, the light scanned on the liquid crystal panel 400 may have different luminance differences due to foreign substances.

However, when the mask of the lattice pattern is additionally provided in the light generating device, light having a finely spaced lattice pattern is scanned or the shadow is projected on the liquid crystal panel 400. In this case, the light or shadow may show a difference in luminance at the specific portion due to a foreign material present on the liquid crystal panel 400, or the grid lines may be cut off, or may have a slightly distorted shape compared to the surrounding lines. will be.

Next, the camera 600 provided on the upper side of the liquid crystal panel 400 is operated to generate a pattern having a different luminance difference or a distorted lattice line pattern on the liquid crystal panel 400 by the light generator 700. After taking (or scanning) the second information (or the second image) regarding the foreign matter having an irregularity or the like, the second information (or the second image) is acquired and transmitted to the computer device 800 (S105).

Thereafter, the computer device 800 will analyze the first information and perform coordinate analysis to determine the positions of defects in the stereotypical and indeterminate systems. This is stored in a separate memory as the modified first information. In addition, the computer device 800 analyzes the second information to perform coordinate analysis to determine the position of the defect of the indeterminate system, and then stores the modified second information in the memory. Next, the computer device 800 logically calculates the modified first information and the second information and detects only the defect of the shaping system (S106). Here, the logical operation is preferably subtracted.

For example, the computer device 800 analyzes the first information to determine coordinates of point defects A and spot defects B, which are defects in the liquid crystal panel 400, and foreign matter defects C on the liquid crystal panel 400. We will analyze and determine the location and store it in memory. In addition, the computer device 800 analyzes the second information, analyzes the coordinates of the foreign material defect C on the liquid crystal panel 400, determines the position, and stores the location in a separate memory. Subsequently, when the logic operation, that is, subtraction of the two position information stored in the memory, only defects of the shaping system for point defects A and spot defects B which are defects in the liquid crystal panel 400 are determined.

In this way, only the substantial internal defects of the liquid crystal panel 400 are determined to determine whether the liquid crystal panel 400 is good or bad (S107), and the liquid crystal panel 400 is unloaded to obtain a good liquid crystal panel 400. In the process, and the defective liquid crystal panel 400 performs a repair process or is discarded (S108).

At the same time, after the liquid crystal panel 400 is unloaded, a new liquid crystal panel 400 is loaded to repeat the above process.

1 is a flowchart illustrating a manufacturing process of a general liquid crystal display device.

2 is a view showing a liquid crystal panel inspection device of the present invention

3 is a flowchart illustrating a liquid crystal panel inspection method using the liquid crystal panel inspection apparatus of FIG. 2.

Claims (11)

A probe device for applying a voltage to the liquid crystal panel by loading a liquid crystal panel; A light generating device provided above the liquid crystal panel to provide light on the liquid crystal panel; After the voltage is applied through the probe device, the first image is obtained by photographing the pattern appearing on the liquid crystal panel, and after the light is provided to the liquid crystal panel from the light generating device, the liquid crystal panel is photographed. A vision unit for acquiring two images; And a control unit for comparing and analyzing the first image and the second image of the liquid crystal panel acquired in conjunction with the vision unit. 2. The liquid crystal panel inspection apparatus according to claim 1, wherein the light generating device can further include a lattice-shaped film at the light exit portion. The liquid crystal panel inspection device according to claim 2, wherein the lattice-shaped film is made of chromium (Cr). The liquid crystal panel inspection apparatus according to claim 1, wherein the vision unit comprises a high resolution CCD camera. The liquid crystal panel according to claim 1, wherein the first image obtained by photographing the pattern of the liquid crystal panel includes an irregular shape system such as a defect pattern of point defects and line defects inside the liquid crystal panel and dust on the liquid crystal panel. Liquid crystal panel inspection apparatus comprising a bad pattern. The liquid crystal panel inspection apparatus according to claim 1, wherein the second image obtained by photographing the liquid crystal panel includes an irregular defect pattern such as dust located on the liquid crystal panel. Loading the liquid crystal panel onto the probe device; Operating the probe device to apply a voltage to the liquid crystal panel; Photographing the liquid crystal panel by operating a camera positioned above the liquid crystal panel, acquiring and storing a first image including an internal defect pattern of the liquid crystal panel and an external defect pattern caused by foreign matter; Turning off a power supply of the probe device and operating a light generating device positioned above the liquid crystal panel to provide light on the liquid crystal panel; Photographing the liquid crystal panel by operating a camera positioned above the liquid crystal panel, acquiring and storing a second image including an external defect pattern; And comparing and analyzing the first and second images to derive an internal defect pattern of the liquid crystal panel. 8. The liquid crystal panel inspection method according to claim 7, wherein the internal defect pattern of the liquid crystal panel is a defective pattern pattern such as point defects and line defects in the liquid crystal panel. The liquid crystal panel inspection method according to claim 7, wherein the light provided to the liquid crystal panel by the light generating device is light of a lattice pattern. The method of claim 7, wherein the comparison and analysis of the first image and the second image is performed by coordinate analysis. The method of claim 7, wherein the derivation of the internal defect pattern of the liquid crystal panel is performed by subtraction of the first image and the second image.
KR1020070069819A 2007-07-11 2007-07-11 Apparatus for inspecting liquid crystal display panel and method for inspecting it KR20090006456A (en)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9052295B2 (en) 2013-04-11 2015-06-09 Samsung Techwin Co., Ltd. Panel inspection method and apparatus
CN105467634A (en) * 2016-01-27 2016-04-06 京东方科技集团股份有限公司 Method and device for detecting color pattern missing of color film substrate

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9052295B2 (en) 2013-04-11 2015-06-09 Samsung Techwin Co., Ltd. Panel inspection method and apparatus
CN105467634A (en) * 2016-01-27 2016-04-06 京东方科技集团股份有限公司 Method and device for detecting color pattern missing of color film substrate

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