KR20070068581A - Polarizer adhesion system and method for adhesion polarizer using the same - Google Patents

Abstract

A system for attaching a polarizer to an LCD(Liquid Crystal Display) panel and a method for attaching a polarizer to an LCD panel by using the system are provided to attach first and second polarizers to the LCD panel while inspecting light which transmits the first polarizer, the LCD panel, and the second polarizer when the first polarizer is attached to the LCD panel and then the second polarizer is attached to the LCD panel. A system for attaching a polarizer(110) to an LCD panel(100) includes a camera for confirming a position on the LCD panel to which the polarizer is attached, a stage and a position determination unit for determining the position of the LCD panel, a backlight unit for providing light in order to inspect alignment of the polarizer, and an adsorber(400) for fixing the LCD panel.

Description

POLARIZER ADHESION SYSTEM AND METHOD FOR ADHESION POLARIZER USING THE SAME}

1 is a view schematically showing a liquid crystal display manufacturing process according to the prior art.

2 is a view illustrating a state in which a polarizing plate adhesion defect occurs in a polarizing plate attaching process of a conventional liquid crystal display.

3A to 3D show a process of attaching a polarizing plate using the polarizing plate attachment system according to the present invention.

4 is a flowchart for explaining a polarizing plate attaching process according to the present invention.

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

100: liquid crystal panel 110: first polarizing plate

120: second polarizer 200: camera

300: stage 301: positioning unit

400: adsorber 500: backlight unit

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a process of attaching a polarizing plate, and more particularly, to a polarizing plate attaching system to a liquid crystal panel, thereby reducing black brightness, thereby improving a contrast ratio of the liquid crystal panel, and attaching a polarizing plate using the same. It is about a method.

Today's liquid crystal displays have been spotlighted as next generation advanced display devices with low power consumption, good portability, technology intensive and high added value. The liquid crystal display device injects a liquid crystal between a TFT substrate including a thin film transistor (TFT) and a color filter substrate, and obtains an image effect by using a difference in refractive index of light according to the anisotropy of the liquid crystal. Means an image display device by a non-light emitting element.

In the current flat panel display field, active matrix liquid crystal displays (AMLCDs) are mainstream. In AMLCD, a thin film transistor is used as a switching element that changes the transmittance of a pixel by adjusting a voltage applied to a liquid crystal of one pixel.

Looking at the manufacturing process of the liquid crystal display, the color filter substrate is formed by sequentially forming a red (R), green (G), blue (B) color filter layer on the upper substrate according to the photolithography process, the array substrate On the lower substrate, thin film transistors and pixel electrodes, which are switching elements, are sequentially formed according to a photolithography process, then the two substrates are bonded together, and then a liquid crystal is injected to form a predetermined liquid crystal display device.

At this time, in order to maintain the cell gap of the upper and lower substrates and to encapsulate the liquid crystal, spacers are dispersed on the substrate, and a seal printing process is performed.

After the bonding process of the liquid crystal display device is as follows.

1 is a view schematically illustrating a manufacturing process of a liquid crystal display according to the prior art.

As shown in FIG. 1, a seal print process is performed on a TFT substrate on which a thin film transistor is formed, a spacer spread process is performed on a color filter substrate (C / F), and then the two substrates are bonded together. The bonding process is carried out.

In the bonding process, the TFT substrate and the color filter substrate are aligned, and then bonded to each other by heat, pressure, and ultraviolet irradiation, and the bonded substrate is cut to manufacture a liquid crystal cell.

When the cell cutting process proceeds as described above, a process of injecting liquid crystal into each liquid crystal cell and a liquid crystal injection process of encapsulating the liquid crystal inlet with ultraviolet curable resin after the liquid crystal injection are performed.

As described above, when the liquid crystal injection process is completed, the liquid crystal cell becomes a liquid crystal panel which is a display element, and a process of attaching a polarizing plate on the surface of the liquid crystal panel is performed. The polarizing plate attaching process aligns the polarizing plate on the surface of the liquid crystal panel, and then attaches the polarizing plate to the surface of the liquid crystal panel by a roller.

The polarizing plate selectively transmits only light vibrating in a specific direction among the light passing through the liquid crystal, and if the attached polarizing plate is not correctly attached to the liquid crystal panel, poor image quality is caused.

When the upper and lower polarizers are attached to the liquid crystal panel as described above, a test signal is applied to the pad region of the liquid crystal panel to perform a defect inspection such as a lighting state or a stain state, and to proceed with an assembly process for attaching a circuit board. Produce finished products.

FIG. 2 is a view illustrating a state in which a polarizing plate adhesion defect occurs in a polarizing plate attaching process of a conventional liquid crystal display. As illustrated, before attaching the polarizing plate 15 to the liquid crystal panel 10, the liquid crystal panel 10 and the polarizing plate are shown. Due to the misalignment of (15), there was a problem that the poor adhesion of the polarizing plate 15 frequently occurs.

Although the polarizing plate 15 is located in the active area 11 of the liquid crystal panel 10, the polarizing plate 15 is attached in a twisted state, thereby causing a defect.

There is a liquid crystal layer oriented by an alignment layer inside the liquid crystal panel 10. The optical axis of the polarizing plate 15 and the rubbing direction of the alignment layer must be exactly aligned horizontally or vertically to normally black or normally white. Optical characteristics of (Normally White) mode can be realized. That is, if the polarizing plate 15 is not correctly attached to the liquid crystal panel 10, problems such as light leakage may occur.

According to the present invention, when the first polarizing plate is attached to the liquid crystal panel and then the second polarizing plate is attached, two polarizing plates are attached to each other while inspecting light passing through the first polarizing plate, the liquid crystal panel, and the second polarizing plate. It is an object of the present invention to provide a polarizing plate attachment system and a method of attaching a polarizing plate using the same, thereby removing light leakage defects.

A polarizing plate attachment system according to the present invention for achieving the above object,

A camera for positioning;

A stage and a positioning unit for determining a position of the liquid crystal panel;

A backlight unit supplying a light source for alignment inspection of the polarizer; And

It characterized in that it comprises an adsorber for fixing the liquid crystal panel.

Here, the camera is used to check the polarizing plate alignment mark displayed on the liquid crystal panel or to measure the transmittance after the light generated by the backlight unit passes through the polarizing plate, characterized in that the backlight unit is rotatable in a predetermined direction.

Polarizing plate attaching method according to another embodiment of the present invention,

Determining a polarizing plate attachment position of the liquid crystal panel;

Attaching a first polarizing plate to one side of the liquid crystal panel;

Positioning a second polarizer on the liquid crystal panel to which the first polarizer is attached;

Irradiating light onto the liquid crystal panel to which the first polarizing plate is attached to measure a transmittance of light passing through the first polarizing plate, the liquid crystal panel, and the second polarizing plate; And

And attaching the second polarizing plate to the liquid crystal panel.

Here, the first polarizing plate is attached to the color filter substrate or the TFT substrate of the liquid crystal panel, and the light transmittance of the light passing through the first polarizing plate, the liquid crystal panel, and the second polarizing plate by irradiating light to the liquid crystal panel having the first polarizing plate is attached. When the mode of the liquid crystal panel is normally white, the second polarizing plate is positioned at the position where the transmittance is highest, and the first polarizing plate, the liquid crystal panel, and the second polarizing plate are irradiated with light. Measuring the transmittance of light passing through the polarizing plate is characterized in that when the mode of the liquid crystal panel is normally black, the second polarizing plate is positioned at the position where the transmittance is minimum.

In addition, adjusting the early-in by rotating the second polarizing plate or the backlight unit so that the value of the transmittance is the highest, and adjusting the early-in by rotating the second polarizing plate or the backlight unit so that the value of the transmittance is the minimum. It is characterized by.

According to the present invention, after attaching the first polarizing plate to the liquid crystal panel and then attaching the second polarizing plate, two polarizing plates are attached to each other while inspecting the light passing through the first polarizing plate, the liquid crystal panel, and the second polarizing plate, thereby failing to attach the polarizing plate. And resulting light leakage defects were eliminated.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

3A to 3D are diagrams illustrating a process of attaching a polarizing plate using the polarizing plate attaching system according to the present invention.

As shown in FIG. 3A, the liquid crystal panel 100, to which the color filter substrate 100a and the TFT substrate 100b are bonded, is checked by using a vision camera 200 and then checking the alignment mark with the polarizer. Decide

When the positioning is confirmed as described above, the liquid crystal panel 100 is fixed to the stage 300 as shown in FIG. 3B, and then the position of the stage 300 and the liquid crystal panel (using the positioning unit 301) are fixed. 100) is mechanically adjusted.

When the position to finally attach the polarizing plate to the liquid crystal panel 100 on the stage 300 is determined as described above, as shown in FIG. 3C, the liquid crystal panel 100 is absorbed and fixed using the adsorber 400. do.

When the liquid crystal panel 100 is raised by the adsorber 400, after the roller 150 and the polarizer 110 are aligned under the adsorber 400, the first polarizer 110 is the liquid crystal panel. The first polarizing plate 110 is attached by the pressure rotation of the roller 150 in a state where it is located at the alignment mark of 100.

The first polarizing plate 110 is first attached to either the outer side of the color filter substrate or the outer side of the TFT substrate of the liquid crystal panel 100.

When the first polarizing plate 110 is attached to the liquid crystal panel 100 as described above, as illustrated in FIG. 3D, the liquid crystal panel 100 having the first polarizing plate 110 attached to the liquid crystal panel 100 intersects or horizontally with the polarizing plate. It is seated on the backlight unit 500 can be confirmed.

The liquid crystal panel 100 mounted on the backlight unit 500 is seated so that the outer surface of the substrate on which the first polarizer 110 is not attached is located in the opposite direction of the backlight unit 500.

As described above, when the liquid crystal panel 100 is seated on the backlight unit 500, the second polarizing plate 120 is fixed to the upper portion of the liquid crystal panel 100, and then a vision camera is placed on the second polarizing plate 120. By positioning the light source 200, the light generated from the backlight unit 500 passes through the first polarizer 110, the liquid crystal panel 100, and the second polarizer 120, and then examines how the light is sensed.

Although not shown in the drawing, the second polarizing plate 120 is fixed to a fixture to be positioned above the liquid crystal panel 100, and the fixture may be rotated or tilted in a predetermined direction by fine adjustment. .

In addition, the backlight unit 500 on which the liquid crystal panel 100 is mounted may also be rotated or tilted in a predetermined direction.

That is, the polarizing plate is aligned by rotating the second polarizing plate 120 or rotating the backlight unit 500.

First, when the mode of the liquid crystal panel 100 is a normally black mode liquid crystal display device, the light traveling from the backlight unit 500 is polarized in the first polarizing plate 110, and then the liquid crystal panel After passing through the liquid crystal layer of (100), it is checked whether the second polarizing plate 120 is completely blocked.

That is, the second polarizing plate 120 is rotated so that the brightness of the light measured by the vision camera 200 has the lowest value to determine the correct attachment position.

As such, when the position of the second polarizing plate 120 having the lowest luminance is determined, the second polarizing plate 120 is attached to the liquid crystal panel 100 using an absorber.

Similarly, when the mode of the liquid crystal panel 100 is a normally white mode liquid crystal display device, the light traveling from the backlight unit 500 is polarized on the first polarizing plate 110 and then the liquid crystal panel ( After passing through the liquid crystal layer of 100, it is examined whether the maximum luminance value appears in the second polarizing plate 120.

The second polarizer 120 is rotated and tilted so that the maximum luminance value appears, and then the second polarizer 120 is attached to the liquid crystal panel 100.

According to the present invention, when attaching one polarizer to the liquid crystal panel and then attaching another polarizer to accurately position the two polarizers attached to the liquid crystal panel, the polarizer according to Malus' law of the polarizer. By determining the location of the light leakage caused by the polarizer adhesion failure was removed.

The law of Malus places two polarizers (prospectors, polarizers), and in order to completely block the light polarized in the first polarizer, the second polarizer must be positioned exactly perpendicular to the first polarizer, and conversely, the first polarizer In order to pass the polarized light as it is, the second polarizing plate must be positioned exactly horizontally with the first polarizing plate.

4 is a flowchart for explaining a polarizing plate attaching process according to the present invention.

As shown in FIG. 4, first, an alignment mark formed on the liquid crystal panel is checked using a camera to determine a position to which the polarizer is attached. (401, 402).

Then, when the alignment mark of the liquid crystal panel is confirmed, the liquid crystal panel is placed on the stage, and then the position of the polarizing plate is attached by using an instrument. (402, 403).

If the alignment mark of the liquid crystal panel is not confirmed, the polarizer alignment mark of the liquid crystal panel is checked again using a vision camera (402 and 401).

When the position of the upper or lower polarizing plate is determined by the mechanism as described above, the polarizing plate is attached using a roller while the liquid crystal panel is adsorbed with the adsorber.

The attached polarizing plate is either an upper polarizing plate to be attached on the color filter substrate or a lower polarizing plate to be attached on the TFT substrate, and it does not matter which one is attached first.

When one of the upper or lower polarizers is attached to the liquid crystal panel by a roller as described above, the liquid crystal panel is moved and fixed on the backlight unit, and then the other polarizer to be attached to the liquid crystal panel is placed on the backlight unit. Located at the top (405)

Then, by rotating one of the remaining polarizing plate or the backlight unit, the position is set by checking whether the transmittance of light generated from the backlight unit is maximum or minimum. This process is repeated until the maximum or maximum transmittance is obtained (406, 407).

That is, when the liquid crystal panel is normally black, the position where the transmittance is minimum is set. When the liquid crystal panel is normally white, the position where the transmittance is maximum is set.

As such, when the setting process is completed, the remaining polarizing plate is attached to the liquid crystal panel.

In the present invention, by attaching any one of the polarizing plate to be attached to the liquid crystal panel first by using the characteristics of the polarizing plate, and then aligning the optical axis of the remaining polarizing plate and the attached polarizing plate attached to remove the polarizing plate adhesion defects.

The present invention is not limited to the above-described embodiments, and various changes can be made by those skilled in the art without departing from the gist of the present invention as claimed in the following claims.

As described in detail above, the present invention has an effect of removing the polarization plate attachment defect by aligning the polarizing plate by measuring the light passing through the liquid crystal panel after attaching one polarizing plate and then attaching the other polarizing plate.

In addition, according to whether the normal black or normal white mode is applied, the amount of light passing through the polarizing plate may be measured to implement an accurate alignment of the polarizing plate.

In addition, by removing the defect with the polarizing plate, there is an effect of removing the light leakage defect of the liquid crystal panel.

Claims (9)

A camera for positioning; A stage and a positioning unit for determining a position of the liquid crystal panel; A backlight unit supplying a light source for alignment inspection of the polarizer; And And a adsorber for fixing the liquid crystal panel. The system of claim 1, wherein the camera is used to check a polarizer alignment mark displayed on the liquid crystal panel or to measure transmittance after light generated by the backlight unit passes through the polarizer. The polarizing plate attachment system of claim 1, wherein the backlight unit is rotatable in a predetermined direction. Determining a polarizing plate attachment position of the liquid crystal panel; Attaching a first polarizing plate to one side of the liquid crystal panel; Positioning a second polarizer on the liquid crystal panel to which the first polarizer is attached; Irradiating light onto the liquid crystal panel to which the first polarizing plate is attached to measure a transmittance of light passing through the first polarizing plate, the liquid crystal panel, and the second polarizing plate; And attaching the second polarizing plate to the liquid crystal panel. The method of claim 4, wherein the first polarizing plate is attached to a color filter substrate or a TFT substrate of the liquid crystal panel. The liquid crystal panel according to claim 4, wherein the liquid crystal panel having the first polarizing plate is irradiated with light to measure the transmittance of light passing through the first polarizing plate, the liquid crystal panel, and the second polarizing plate. Positioning the second polarizing plate in the position where the transmittance is the highest. The liquid crystal panel according to claim 4, wherein the liquid crystal panel having the first polarizing plate is irradiated with light to measure the transmittance of light passing through the first polarizing plate, the liquid crystal panel, and the second polarizing plate. Positioning the second polarizing plate in a position where the transmittance is minimum. 7. The method of attaching a polarizing plate according to claim 6, wherein the early-in is adjusted by rotating the second polarizing plate or the backlight unit so that the value having the highest transmittance appears. The method of claim 7, wherein the second polarizing plate or the backlight unit is rotated to adjust the early-in such that the minimum transmittance appears.

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