KR100685931B1 - Method for Inspecting Gravity in Liquid Crystal Display Device - Google Patents

Abstract

The present invention relates to a gravity inspection method of a liquid crystal display device which performs inspection after rotating the panel simultaneously with heating to improve inspection speed when inspecting a gravity failure, the gravity inspection device comprising a heating chamber, a process chamber and an inspection table In the gravity test method of the liquid crystal display using a device comprising the steps of: loading a cassette containing a plurality of liquid crystal panels in the standing state to the gravity tester, moving the cassette to a heating chamber and heating, and in the heating chamber the Moving the cassette to a process chamber, taking the cassette out of a liquid crystal panel unit, rotating the liquid crystal panel under a predetermined heating condition, moving the liquid crystal panel to a test bench, and determining whether the liquid crystal panel is unsatisfactory. Characterized in that it comprises a step.

Poor gravity, rotation principle, gravity test, gravity checker

Description

Gravity test method of liquid crystal display {Method for Inspecting Gravity in Liquid Crystal Display Device}

1 is an exploded perspective view showing a general liquid crystal display device

2 is a photograph showing gravity failure occurring in a liquid crystal display

3 is a cross-sectional view taken along line II ′ of FIG. 2;

Figure 4 is a gravity tester used in the gravity test method of the present invention

5 is a process flow chart of the gravity test method of the present invention

* Description of symbols on the main parts of the drawings *

110: robot hand 130: process chamber

150: heating chamber 170: defective port

190: Inspection Table 200: Good Product Port

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display, and more particularly, to a gravity inspection method in which an inspection is performed after rotating a panel simultaneously with heating to improve inspection speed when inspecting a gravity failure.

As the information society develops, the demand for display devices is increasing in various forms, and in recent years, liquid crystal display devices (LCDs), plasma display panels (PDPs), electro luminescent displays (ELD), and vacuum fluorescent (VFD) Various flat panel display devices such as displays have been studied, and some of them are already used as display devices in various devices.

Among them, LCD is the most widely used as the substitute for CRT (Cathode Ray Tube) for mobile image display device because of its excellent image quality, light weight, thinness, and low power consumption. In addition to the use of the present invention has been developed in various ways such as a television and a computer monitor for receiving and displaying broadcast signals.

In order to use such a liquid crystal display as a general screen display device in various parts, it is a matter of how high quality images such as high definition, high brightness and large area can be realized while maintaining the characteristics of light weight, thinness and low power consumption. Can be.

Hereinafter, a liquid crystal display and a gravity failure caused by the conventional liquid crystal display will be described with reference to the accompanying drawings.

1 is an exploded perspective view showing a general liquid crystal display.

A general liquid crystal display device, as shown in FIG. 1, is injected between a first substrate 1 and a second substrate 2 bonded to each other with a predetermined space, and between the first substrate 1 and the second substrate 2. It consists of the liquid crystal layer 3.

In more detail, the first substrate 1 may have a plurality of gate lines 4 in one direction and constant in a direction perpendicular to the gate lines 4 at regular intervals to define the pixel region P. FIG. A plurality of data lines 5 are arranged at intervals. In addition, a pixel electrode 6 is formed in each pixel region P, and a thin film transistor T is formed at a portion where the gate line 4 and the data line 5 cross each other, so that the thin film transistor is formed. The data signal of the data line is applied to each pixel electrode according to the signal of the gate line.

In addition, a black matrix layer 7 is formed on the second substrate 2 to block light in portions other than the pixel region P, and portions R corresponding to the respective pixel regions are formed to express colors. , G, B color filter layers 8 are formed, and a common electrode 9 for realizing an image is formed on the color filter layers 8.

In the liquid crystal display as described above, the liquid crystal layer 3 formed between the first and second substrates is aligned by an electric field between the pixel electrode 6 and the common electrode 9, and the liquid crystal layer 3 of the liquid crystal layer 3 is aligned. The amount of light passing through the liquid crystal layer 3 can be adjusted according to the degree of alignment to express the image.

Such a liquid crystal display device is called a twisted nematic (TN) mode liquid crystal display device, and the TN mode liquid crystal display device has a disadvantage of having a narrow viewing angle and an in-plane switching (IPS) mode for overcoming the disadvantages of the TN mode. Liquid crystal display devices have been developed.

In the IPS mode liquid crystal display, a pixel electrode and a common electrode are formed parallel to each other at a predetermined distance in a pixel area of the first substrate so that a lateral electric field (horizontal electric field) is generated between the pixel electrode and the common electrode and the lateral electric field is generated. This is to align the liquid crystal layer.

Meanwhile, a general method of manufacturing a liquid crystal display device may be classified into a liquid crystal injection method manufacturing method and a liquid crystal drop method manufacturing method according to a method of forming a liquid crystal layer between the first and second substrates.

First, the liquid crystal injection method will be briefly described as follows.

The container containing the liquid crystal material to be injected and the liquid crystal panel into which the liquid crystal is to be injected are placed inside the chamber, and the pressure in the chamber is maintained in a vacuum state to remove moisture from the liquid crystal material or the inner wall of the container and to bubble. At the same time, the interior space of the liquid crystal panel is vacuumed.

The liquid crystal injection hole of the liquid crystal panel is immersed in or contacted with a container containing a liquid crystal material in a desired vacuum state, and then the pressure inside the chamber is changed from a vacuum state to an atmospheric pressure state, and the pressure inside the liquid crystal panel and the pressure of the chamber. By the difference, the liquid crystal material is injected into the liquid crystal panel through the liquid crystal injection hole.

There existed the following problems in the liquid crystal display device manufacturing method of such a liquid crystal injection system.

First, after cutting into a unit panel, the liquid crystal injection hole is immersed in the liquid crystal liquid by maintaining the vacuum state between the two substrates, so that the liquid crystal injection takes a lot of time, the productivity is reduced.

Second, in the case of manufacturing a large-area liquid crystal display device, when the liquid crystal is injected by the liquid crystal injection method, the liquid crystal is not completely injected into the panel, which causes a defect.

Third, since the process is complicated and time-consuming as described above, several liquid crystal injection equipment is required, which requires a lot of space.

Accordingly, in order to overcome the problems of the liquid crystal injection method, a method of manufacturing a liquid crystal drop type liquid crystal display device in which a liquid crystal is dropped on one of two substrates and then the two substrates are bonded to each other has been developed.

The liquid crystal display device manufacturing method of the liquid crystal dropping method is a method of bonding two substrates after dropping an appropriate amount of liquid crystal onto any one of the two substrates before bonding the two substrates together.

FIG. 2 is a photograph illustrating gravity failure occurring in a liquid crystal display, and FIG. 3 is a cross-sectional view of the structure along the line II ′ of FIG. 2.

As shown in FIG. 2, the gravity failure phenomenon is observed at the edge of the liquid crystal panel close to the ground. This is because, when the liquid crystal panel is placed in a high temperature state, the edge of the liquid crystal panel close to the ground bulges bulge by the property that the liquid crystal expands with temperature.

As shown in FIG. 3, when the upper and lower sides of the liquid crystal panel 10 are cut, the column spacer 20 positioned at the lower edge of the liquid crystal panel 10 supports the first and second substrates 1 and 2 by the expansion force of the liquid crystal. It does not, and the phenomenon which falls from the 1st board | substrate 1 arises. In particular, when the liquid crystal panel 10 is upright in the state in which the liquid crystal is dripped excessively, the phenomenon that the liquid crystal flows toward the ground close to the ground under the influence of gravity becomes severe.

Here, a seal pattern 25 is formed at an edge of the liquid crystal panel 10 to bond the first and second substrates 1 and 2 to each other, and between the first and second substrates 1 and 2. The liquid crystal layer 3 is formed of the liquid crystal dropped therein. As shown, the cell gap between the region in which gravity failure occurs and the region in which gravity failure does not occur is different from the liquid crystal layer 3, and this portion appears to be broken in appearance when the liquid crystal display is driven.

However, the conventional liquid crystal display device as described above has the following problems.

When the liquid crystal is filled by the liquid crystal dropping method, an appropriate amount may not be dropped into the liquid crystal panel, but may be unfilled or excessively dropped.

In particular, when an excessive drop is added, when the liquid crystal panel is erected, an excessive amount of liquid crystal concentrates on the side close to the ground, and when the liquid crystal expands at a high temperature in this portion, a phenomenon that looks bulging occurs. This is called gravity failure, which lowers the visibility and, in severe cases, cannot use a liquid crystal panel in which gravity failure occurs. Therefore, such gravity failure should be inspected prior to release to select only products having a certain level of gravity failure. However, conventionally, there is no device for inspecting such a gravity failure, and in large part relied on the direct operation of humans.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems and provides a gravity inspection method of a liquid crystal display device which performs inspection after rotating the panel simultaneously with heating to improve inspection speed when inspecting a gravity defect. There is a purpose.

Gravity test method of the liquid crystal display device of the present invention for achieving the above object is a gravity test method of the liquid crystal display device using a gravity tester comprising a heating chamber, a process chamber and the inspection table, a plurality of liquid crystal panels Loading the cassette into the gravity tester, moving the cassette to a heating chamber and heating the cassette, moving the cassette from the heating chamber to the process chamber, and taking out the cassette from the liquid crystal panel unit. And rotating the liquid crystal panel under a predetermined heating condition, moving the liquid crystal panel to a test stand, and determining whether the liquid crystal panel is unsatisfactory.

The heating temperature in the heating chamber is 55 ~ 70 ℃.

The heating time in the heating chamber is 10-30 minutes.

The predetermined heating conditions in the process chamber are the same temperature and atmosphere as the heating conditions in the heating chamber.

The liquid crystal panel is rotated in the process chamber at 500 to 1000 rpm.

The rotation time in the process chamber is 10 seconds to 1 minute.

Taking out each of the liquid crystal panel units and moving the liquid crystal panel to a test stand is performed by a robot hand.

Hereinafter, a gravity test method of the liquid crystal display of the present invention will be described in detail with reference to the accompanying drawings.

4 is a gravity tester used in the gravity test method of the present invention.

As shown in Figure 4, the gravity tester used in the gravity test method of the present invention, the heating chamber 150, the process chamber 130, the robot hand 110, the inspection table 190, the non-defective port 200 and defective port It comprises 170.

The heating chamber 150 is loaded with a cassette containing a plurality of liquid crystal panels on the upright form. The heating chamber 150 is heated to a temperature of 55 to 70 ° C. for 10 to 30 minutes while allowing the cassette to pass through the first to fourth heating chambers 151, 152, 153, and 154.

In addition, the process chamber 130 takes out the liquid crystal panel by the liquid crystal panel unit from the cassette continuously loaded from the heating chamber 150, and rotates the liquid crystal panel under the same temperature condition as the heating chamber 150. Here, the process chamber 130 to rotate the liquid crystal panel at a speed of about 500 ~ 1000rpm.

The robot hand 110 takes out a liquid crystal panel for each unit from the process chamber 130 or receives a liquid crystal panel from the process chamber 130 and moves the liquid crystal panel to the test table 190. The robot hand 110 is rotatable at an angle with respect to the center axis to rotate the liquid crystal panel to the inspection table 190, the robot hand 110 is provided with a plurality of hands, the vacuum hole on the surface of the hand A vacuum hole is provided, and the liquid crystal panel is taken out to adsorb and move the liquid crystal panel through the vacuum hole.

The inspection table 190 determines whether an abnormality occurs due to heating in the liquid crystal panel, that is, whether a gravity failure occurs. If there is no abnormality, the corresponding liquid crystal panel is moved to the good quality port 200. The liquid crystal panel is moved to the defective port 170.

Here, a door that opens and closes up and down is provided on a surface where the process chamber 130 and the robot hand 110 face each other, and the robot hand 110 may enter and exit the process chamber 130.

The reason why the liquid crystal panel is vertically disposed in the cassette to move the chambers is that the failure of gravity is easy to observe in the state where the liquid crystal panel is standing (vertically positioned).

Hereinafter, the gravity test method of the liquid crystal display device using the above-mentioned gravity tester is demonstrated.

5 is a process flowchart of the gravity inspection method of the present invention.

As shown in FIG. 5, the gravity test method of the liquid crystal display device of the present invention is performed by first loading a cassette containing the plurality of liquid crystal panels in a standing state to the aforementioned gravity tester (S100).

Then, the cassette is moved to a heating chamber and heated (S110). At this time, the heating temperature in the heating chamber is 55 ~ 70 ℃, the heating time at this time is 10-30 minutes.

Then, the cassette is moved to the process chamber in the heating chamber (120).

Subsequently, the door is opened in the process chamber, the robot hand is drawn in and the liquid crystal panel is taken out for each unit, and the unit liquid crystal panel is rotated under a predetermined heating condition (S130). At this time, when the unit liquid crystal panel is heated and rotated, the robot hand is in a state in which the door comes out from the closed state. In addition, the heating and rotation are performed in a state in which the liquid crystal panel is upright. At this time, the level of the liquid crystal panel is set to be between 45 ° to 90 ° with respect to the surface of the liquid crystal panel on the basis of the ground. The heating conditions are the same conditions (same temperature and atmosphere) as the heating conditions in the heating chamber 150. The rotation speed of the said liquid crystal panel at this time is 500-1000 rpm, and the time is made into 10 second-1 minute.

Subsequently, the liquid crystal panel is moved to a test stand (S140).

The inspection table determines the good or bad of the liquid crystal panel (S150). In this case, the non-determination of the liquid crystal panel is a state in which the backlight unit is positioned below the transparent inspection table at the inspection table, the lower polarizer is fixed to the upper surface of the inspection table, and the liquid crystal panel is placed on the lower polarizing plate. By turning on the backlight unit, the inspector rotates the upper polarizer on the top of the liquid crystal panel with respect to the center of the liquid crystal panel or gradually shifts the left and right or up and down directions to observe the color change. At this time, the site where the gravity failure occurred is observed with a different color than other sites.

In the above-described process, the liquid crystal panel judged as good quality is moved to the good quality port, and the liquid crystal panel determined as defective is moved to a bad quality port. Here, a good product refers to a liquid crystal panel whose degree is so small that the observer does not recognize even if there is no part observed in other colors or a different color occurs in the gravity inspection on the inspection table described above.

As described above, the gravity test method of the liquid crystal display device of the present invention shortens the gravity failure detection time and improves productivity by rotating the liquid crystal panel and rotating the same to use the gravity test.

For example, in the case of a gravity test after heating a plurality of liquid crystal panels arranged in a cassette in a heating chamber, when the heating time is short, the gravity failure phenomenon cannot be discriminated well, so at least two hours should be heated. do. That is, when the liquid crystal panel is upright, the gravity flow phenomenon can be observed only when the time flowing down to the ground by gravity and the time taken for the liquid crystal to expand to some extent can be secured.

However, in the gravity test method of the liquid crystal display of the present invention, the liquid crystal panel is first heated, and then rotated under a predetermined heating condition for a second short time to shorten the reaction time required for the occurrence of a poor gravity phenomenon.

The gravity tester of the liquid crystal display of the present invention as described above has the following effects.

First, in detecting gravity failure of the liquid crystal panel, after heating for 10 to 30 minutes first, taking out each unit liquid crystal panel and rotating for 10 seconds to 1 minute under the same heating conditions, the time for detecting gravity failure is shortened. Productivity can be improved.

Second, as described above, by using the centrifugal force along with gravity through the rotation of the liquid crystal panel, the gravity failure detection time is shortened, which enables early detection of the abnormality of the gravity failure, thereby preventing the loss occurring during the long time heating of the liquid crystal panel. .

Claims (7)

In the gravity test method of the liquid crystal display device using a gravity tester comprising a heating chamber, a process chamber and an inspection table, Loading a cassette containing the plurality of liquid crystal panels on the gravity checker; Moving the cassette to a heating chamber and then heating the cassette; Moving the cassette from the heating chamber to a process chamber; Taking out the liquid crystal panel unit from the cassette and rotating the liquid crystal panel under a condition in which the heating temperature is 55 to 70 ° C; Moving the liquid crystal panel to a test stand; And And determining the non-payment of the liquid crystal panel. delete The method of claim 2, The heating time in the heating chamber is a gravity test method of the liquid crystal display device, characterized in that 10 to 30 minutes. The method of claim 1, The predetermined heating condition in the process chamber is the same temperature and atmosphere as the heating condition in the heating chamber. The method of claim 4, wherein The rotation of the liquid crystal panel in the process chamber is a gravity inspection method of the liquid crystal display device, characterized in that consisting of 500 ~ 1000rpm. The method of claim 5, The rotation time in the process chamber is a gravity test method of the liquid crystal display device, characterized in that 10 seconds ~ 1 minutes. The method of claim 1, And taking out each of the liquid crystal panel units and moving the liquid crystal panel to a test stand by a robot hand.

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