JP2908372B2 - Dust removal roller for LCD display manufacturing - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dust removing roller for manufacturing a liquid crystal display, and more particularly to a dust removing roller for removing dust existing between a glass surface of a liquid crystal display and a polarizing plate.

[0002]

2. Description of the Related Art One of the mainstream liquid crystal displays (hereinafter, LCD) is a twisted nematic (hereinafter, TN) type LCD. The operation principle of the TN type LCD is as follows. First, the incident light emitted from the light source is selectively transmitted through the polarizer only in a specific vibration direction. Next, the polarized light is modulated into a predetermined polarization state while passing through a liquid crystal layer which exists between two glass substrates and whose arrangement is controlled by an applied voltage. Finally, the modulated polarized light is emitted only by the emission side analyzer in a specific direction. The difference in the intensity of the polarized light that is finally emitted at each position on the screen is recognized as an image by the user.

[0003] In a TN type LCD, a polarizing plate used as a polarizer or an analyzer is usually in the form of a film and is used by being attached to a glass substrate. In this case, dust is interposed between the polarizing plate and the glass substrate. Then, display quality is greatly impaired due to the occurrence of light leakage due to the polarization disorder or the shielding of light by foreign matter. The bonding of the polarizing plate to the glass surface is usually performed by a method in which a polarizing plate having an adhesive applied on one side in advance is pasted on the bonded glass surface. As a result of the investigation and analysis, most of the dust between the polarizing plate and the glass surface was obtained by directly sandwiching the dust attached to the glass surface before bonding with the polarizing plate. Therefore, the reduction of dust between the polarizing plate and the glass is related to how to effectively remove dust on the glass surface before bonding the polarizing plate.

Conventionally, for example, the following method has been used as a method of removing dust on glass. (1) A method of shaving glass surface dust with a knife-shaped cutter.

[0005] This method is a method for removing foreign substances adhering to a glass surface with a strong mechanical force, and can remove foreign substances without fail, but has a great risk of damaging the glass surface. (2) A method of polishing the glass surface with a polishing tape.

According to this method, the risk of scratching the glass surface as in (1) is small. However, when this method is applied in mass production, it is necessary to delicately control the amount of polishing with a polishing tape, and thus it becomes necessary to use a relatively expensive apparatus. (3) A method in which a sticky or elastic rubber roller is rotated in contact with the glass surface to transfer foreign matter on the glass to the dust roller surface.

According to this method, there is no damage to the glass surface as in (1), no expensive equipment as in (2) is required, and foreign substances on the glass surface can be removed with a high probability.

The above methods (1) and (2) are generally used for removing foreign substances on the glass surface. However, from the viewpoint of yield loss due to glass flaws and low equipment cost, the method (3) is preferred. Most preferred for mass production.

As an example of a known technique relating to surface cleaning with a rubber roll, Japanese Patent Application Laid-Open No. 5-342571 discloses a method of manufacturing a film for a magnetic recording medium, in which a base film surface is brought into contact with a conductive adhesive roller in advance to remove foreign substances such as dust. After that, the coating of the magnetic material is performed.
However, the conductive adhesive used here expresses conductivity by adding a conductive filler to rubber, and at this time, the original adhesiveness of the rubber is greatly impaired. Also, the brittleness of the rubber increases. For this reason, if this technology is diverted to LCDs, not only will foreign matter firmly adhered to the LCD surface not be removed, but also the brittle rubber material will be scraped off by the hard glass surface, edges, etc. .

In Japanese Patent Application Laid-Open No. Hei 4-221670, an adhesive and conductive cleaning roller is brought into contact with the ink sheet inside the ink cartridge of the printing apparatus before the ink sheet is supplied to the recording head.
The purpose is to remove dust and the like adhering to the ink sheet. However, similarly to the above example, when such a rubber material imparted with conductivity is diverted to an LCD, it is insufficient in capability to remove various foreign substances having a strong adhesive force on the LCD glass surface.

In JP-A-2-131969, a pinch roller made of conductive rubber is used for the purpose of preventing electrostatic charging of a recording member and ink inside a thermal printer. The conductive rubber roller in this example is intended only to remove static electricity inside the printer device, and it is almost impossible to remove foreign matter adhered to the LCD glass surface by various mechanisms such as mechanical and interface interaction. is there.

Japanese Patent Application Laid-Open No. 63-292179 discloses a toner fixing section in an image forming apparatus such as an electrophotographic photographic apparatus.
Contaminants adhering to the fixing heat roller are cleaned with a roller made of foamed silicone rubber or the like, and static electricity on the surface of the heat roller is removed with a charging brush. However, when the present technology is diverted to an LCD, the removal of foreign matter from the LCD surface and the gradual charging are performed separately, so that damage caused in a short time due to static electricity generated at the moment of removing the foreign matter cannot be prevented.

In JP-A-3-166982, dust is removed from a thermal transfer sheet by bringing a dust adhering roller into contact with the thermal transfer sheet in a thermal transfer apparatus. It is described that this roller is made of rubber and imparts conductivity as necessary. However, as already described in some of the above examples, it is not practical to remove foreign substances on the LCD surface by using a conductive rubber because the disadvantages are a decrease in removal ability and an increase in dust generation.

[0014]

In the method (3) of the prior art described above, in which a sticky or elastic rubber roller is brought into contact with a glass surface and rotated to transfer foreign matter on the glass to the surface of the rubber roller, Although the above foreign matter can be effectively removed, the rubber material used is insulative, and a large amount of static electricity is generated due to the wear of the rubber roller and the glass on the glass surface, so that there is a problem that a defect due to the static electricity occurs. . In particular, a thin film transistor (hereinafter, TFT) type active matrix type LCD (hereinafter, AM-LCD) in which a transistor is arranged for each display element.
In this case, since the TFT element is easily destroyed by static electricity, the effect of the static electricity on the product yield is enormous.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a dust removing roller which is improved so as not to cause a problem of destruction of an LCD device due to generation of static electricity when a rubber roller system which has a good foreign matter removing efficiency and a low equipment cost is applied. I do.

[0016]

The dust removing roller according to the present invention comprises a cylindrical rubber roller and a ground terminal. A plurality of ring-shaped conductive layers made of a material having electrical conductivity are arranged on the outer peripheral surface of the cylindrical rubber roll. This conductive layer occupies only a limited portion of the roller surface so as not to hinder the removal of foreign substances by the rubber roller surface. The ratio occupying the surface of the conductive layer is 1/5 or less, and is 1/10 or less as a ratio that hardly hinders the efficiency of foreign matter removal.

It is necessary that at least two conductive layer rings are arranged on the roller surface, and the larger the number, the more effective the static electricity removing ability. The spacing between the conductive layer rings is almost equal as a basic pattern, but depending on the structure and characteristics of the target product to be applied, it may be more efficient to remove static electricity if the spacing is not always equal. Such application examples are also included in the scope of the present invention.

The material of the conductive layer ring may be any material that satisfies at least the electrical conductivity required for removing static electricity, and more specifically, the volume resistivity is 106 Ω · cm or less. Specific examples of the material include a metal material such as stainless steel, a metal material such as a conductive resin such as a carbon dispersed resin, and a conductive resin such as a carbon dispersed resin.

In the roll of the present invention, the conductive layer ring on the surface thereof is in contact with a ground terminal for discharging static electricity at a position different from the contact surface with the LCD panel. The material and shape of the ground terminal are not limited as long as the ground terminal can smoothly contact the roll and the conductive layer ring and can effectively conduct static electricity to the outside. However, from a practical point of view, a metal or conductive resin rod or roll is the simplest.

The dust removing roller of the present invention having the above-mentioned roll and ground terminal is applied to the LCD panel immediately before attaching the polarizing plate to the LCD panel in the LCD manufacturing process.

When the dust removal roller of the present invention is applied to the LCD panel surface, static electricity generated by friction between the LCD glass surface and the gum roll surface is transferred to the conductive layer ring through the rubber surface and a shallow layer near the surface. And is gradually discharged. When the static electricity reaches the conductive layer ring, it is immediately transmitted through the ring and discharged to the ground terminal in contact with the ring. In this way, the static electricity generated by the triboelectric charging is quickly removed, and the destruction of the LCD element due to the static electricity is prevented.

In the dust removal roller of the present invention, the ratio of the conductive layer to the rubber surface is 1/5 or less, and 1 /
Since it is 10 or less, most of the area on the roll surface serves to remove foreign matter, and therefore, the foreign matter removal ability is comparable to that of a conventional dust removal roller.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a state in which dust on an LCD panel is removed using a dust removal roller according to the first embodiment of the present invention. FIG. 2A is a perspective view showing a rubber roll portion of the dust removing roller of the present invention.
FIG. 2B is a diagram showing a cross section taken along the line aa ′ of FIG. The dust removal roller of the present embodiment includes a rubber roll 1 provided with a conductive member on the surface and a metal roll 2 for grounding.
The ground metal roll 2 is connected to a ground terminal.

As the rubber roll 1 having the ability to remove dust based on elasticity, a cylindrical roll having a diameter of 40 mm and a length of 300 mm was used as a dust removing roll. As shown in FIG. 2, SUS30 having a diameter of 0.1 mm
The 4 wires 7 were spirally wound in the circumferential direction at a pitch interval of 10 mm. The two rubber rolls were fixed on the line conveyor 4 in front of the LCD panel polarizing plate sticking device 5. The fixed position was set so that the roll rotation direction coincided with the traveling direction of the LCD panel 3 and the roll surface was pressed into the glass surface of the LCD panel by 0.3 mm. It was driven by a rotation motor (not shown) of a rubber roll, and the rotation speed was set so as to be synchronized with the traveling speed of the LCD panel 3 by the conveyor.

Made of SUS304, diameter 7 mm, length 35 m
The two metal rolls 2 for grounding, which rotate freely,
Each of the rubber rolls 1 was fixed in contact with each other in parallel. This ground metal roll 2 was connected to ground through a fixed shaft. In the above description, a rubber roll made entirely of rubber is used. However, a columnar roll having a resin layer exhibiting adhesiveness or elasticity at least on its surface, for example, a rubber layer, may be used.

After 100 TFT-LCD panels were passed between the dust removing rollers thus installed, a polarizing plate was immediately attached. Of the 100 LCD panels,
There were no electrostatic damages, and there were three dusts between the polarizing plate and the glass.

Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 3A is a perspective view of a rubber roll according to the second embodiment, and FIG. 3B is a cross-sectional view taken along the line bb '. 1mm width and 2m depth in the circumferential direction on unprocessed rubber roll
m groove was carved in a circle. 29 such grooves were formed at 10 mm intervals. Next, an uncured urethane resin having carbon dispersed therein was injected into the groove to form a conductive resin portion 9, and after curing, the surface was shaved to obtain a smooth cylindrical shape.

Next, this roll 1 was used, and all other settings were the same as in FIG. 1, and 100 TFT-LCDs were distributed. Of the 100 LCDs, the one with electrostatic breakdown was 0
And two dusty objects between the polarizing plate and the glass. In the second embodiment, the conductive resin portion 9
Is composed of resin in which carbon black is dispersed,
In addition, a conductive resin such as a conductive polymer or an ion conductive polymer may be used.

As Comparative Example 1, the same unprocessed rubber roll as that of the first embodiment, that is, a rubber roll without a metal wire was used as it is, and all other settings were the same as those of the first embodiment (FIG. 1). And 100 TFT-LCDs were distributed. Of the 100 LCDs, two had electrostatic damage and three had dust between the polarizer and the glass.

In Comparative Example 2, no rubber roll was used, and all other settings were the same as in the first embodiment.
100 LCDs were distributed. Of the 100 LCDs, 0 had electrostatic breakdown and 10 had dust between the polarizing plate and the glass.

[0031]

The dust removing roller of the present invention can effectively remove dust adhering to the surface of the LCD panel before attaching the polarizing plate without electrostatically destroying the LCD panel.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a state in which dust is removed using a dust removal roller according to a first embodiment of the present invention.

FIGS. 2A and 2B are a perspective view and a cross-sectional view of a rubber roll according to the first embodiment of the present invention.

FIGS. 3A and 3B are a perspective view and a sectional view of a rubber roll according to a second embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rubber roll 2 Grounding metal roll 3 LCD panel 4 Conveyor 5 Polarizer attaching device 6,8 Rubber part 7 SUS wire 9 Conductive resin part

Claims (3)

(57) [Claims] 1. A cylindrical roll having a resin layer exhibiting tackiness or elasticity on at least the surface thereof. A plurality of ring-shaped conductive material layers are provided on the surface of the resin layer. A dust removing roller for manufacturing a liquid crystal display, wherein the layer is in contact with a metal roll for discharging static electricity. 2. The dust removing roller according to claim 1, wherein the conductive material is a conductive resin. 3. The dust removal roller according to claim 1, wherein the conductive material is a metal.