JPH03175423A - Rubbing device for liquid crystal display element orienting film - Google Patents

Abstract

PURPOSE:To obtain uniform and stable orientation performance and to improve the performance and quality by adjusting the gap between the base cloth surface of rubbing cloth and a coating film for the orienting film by a pressure transmission mechanism and a pressure detection controller and making the coating film for the orienting film abut on the surface of the rubbing cloth with constant pressure. CONSTITUTION:The gap between the base cloth surface of the rubbing cloth 12 and the coating film for the orienting film is controlled by adjusting a pressure medium, e.g. compressed air by the pressure transmission mechanism 4 and pressure detection controller 5 so that the coating film for the orienting film on a glass substrate 1 abuts on the surface of the rubbing cloth 12 with the invariably constant pressure. Consequently, the orienting film which has the uniform and stable orientation performance is obtained and an irregularity in the orientation of the orienting film of the liquid crystal display element is reduced to improve the display quality.

Description

[Detailed Description of the Invention] [Summary] Regarding a rubbing device for an alignment film of a liquid crystal display element, the purpose is to reduce unevenness in alignment of an alignment film of a liquid crystal display element and improve display quality. A rubbing cloth winding roller rotatably attached to a support rack, a rubbing cloth wound around the rubbing cloth winding roller, a roller drive device for rotating the rubbing cloth winding roller, and a roller support rack mounted thereon. a pedestal to be fixed, a stage transport mechanism attached to the pedestal, a power supply/control device for driving the stage transport mechanism;
The stage conveyance mechanism includes a stage for mounting a glass substrate, which is conveyed below the rubbing cloth wrapping roller parallel to the roller surface, and a stage for mounting a glass substrate, which is movably provided on the upper surface of the stage. a pressure transmission mechanism that moves the surface plate up and down so that the glass substrate contacts the rubbing cloth with a predetermined pressure; and a pressure detection/control device that controls the pressure applied to the pressure transmission mechanism. A rubbing device for a liquid crystal display element alignment film is configured to include at least the following.

[Industrial application field]

The present invention relates to improvements in rubbing equipment for alignment films for liquid crystal display elements with excellent display quality.

In recent years, the development of display devices has been remarkable, and in particular, flat displays have rapidly become popular due to their thinness and light weight. Among them, liquid crystal display devices have a low driving voltage and are inexpensive, so they are being actively introduced into the field of office automation equipment such as personal computers and word processors.

The liquid crystal display elements used for these applications are required to display characters and graphics, so they must have large screens, many pixels,
With the trend toward high definition, there is a need for an apparatus for manufacturing high-quality liquid crystal display elements free of display defects, such as a rubbing apparatus for forming alignment films with uniform performance.

[Conventional technology]

FIG. 3 is a diagram showing an example of the basic configuration of a liquid crystal display device. In the figure, l is a glass substrate, and 110 is formed on a glass substrate. For example, a striped transparent electrode 101 made of ITO (In20z 5nO2) is an alignment film formed to cover the striped transparent electrode 110. For example, the alignment treatment is performed by brushing a polyimide resin film with a nylon brush. That's what I did. 150 is an adhesive layer for sealingly bonding the peripheral edges of two glass substrates;
A gap-like space is formed between the two glass substrates by a spacer (not shown), and the liquid crystal 200. For example, twisted nematic, or TN (Twist
ed NematiC) Liquid crystal is injected and sealed. 3
00 are two polarizing plates arranged orthogonally to each other.

The two glass substrates have striped transparent electrodes! 10 are arranged perpendicularly to each other to form an X-Y matrix intersection. For example, when light is applied from below, it becomes linearly polarized light at the polarizing plate 300 below, and depending on the presence or absence of an electric field in the liquid crystal layer, Depending on the rotation of the polarizing tube, the upper polarizing plate 300 selects either transmission or non-transmission of light. That is, depending on whether or not an electric field is applied, light is switched at each matrix intersection point, and a black and white image, for example, is displayed as viewed from the observer 400.

Here, the alignment film 101 gives a twist angle to the liquid crystal molecules injected between the two glass substrates l, and is one of the extremely important factors determining the performance of the liquid crystal display element.

Currently, the most commonly used alignment film for liquid crystal display elements is to form a transparent electrode on a glass substrate, cover it with polyimide resin, dry it, and perform a rubbing treatment to give alignment to the liquid crystal molecules. ing.

Figure 4 is a diagram illustrating the orientation treatment by rubbing.
100 is a coating film for alignment film, for example, a polyimide resin film applied by a transfer printing method; 15' is a stage conveyance mechanism for conveying stage 3', for example, a belt conveyor or rollers; Such as conveyors. ll is the rubbing cloth winding roller, I
2 is a rubbing cloth, for example, a nylon base cloth with a thickness of about 0.7 mm, and a so-called pile 120, which is a fiber with a thickness of about 30 μmφ and a length of about 3 mm, is planted perpendicularly to the surface of the base cloth. be.

That is, when the glass substrate l passes under the rotating rubbing cloth 12, the coating film 100 for alignment film passes under the rubbing cloth 1.
The friction by the pile 120 of No. 2 imparts strain anisotropy to the rubbing direction to form the alignment film 101, which stabilizes the alignment of liquid crystal molecules at the interface of the alignment film injected into the liquid crystal display element and sets the required twist angle. can do.

FIG. 5 is a diagram showing an example of a conventional rubbing device, in which (A) is a front view and (B) is a side view.

In the figure, IO is a roller support rack, 13a is a roller drive device (motor section) for rotating the rubbing cloth wrapping roller 11, and 13t) is a roller drive device (power supply section). Reference numeral 14' denotes a pedestal, 3'' a stage on which the glass substrate I is placed, 31 a rotary gear attached to the stage 3'', and 15b a stage transport mechanism. For example, the gear belt 15a that meshes with the rotating gear 31 also constitutes a stage conveyance mechanism. For example, it is a motor section that drives the gear belt 15b. 16 is a stage transport mechanism power supply/control device that drives and controls the stage transport mechanisms 15a and 15b.

In addition, parts that are equivalent to those explained in the above countries are given the same reference numerals, and are equivalent parts.

The explanation regarding this will be omitted.

The rubbing cloth wrapping roller 11 is attached to a roller support stand lO, and its height, that is, the distance from the rubbing cloth, is determined by height adjustment mechanisms 20 installed at both ends.

For example, manual adjustment is performed using a screw feed mechanism.

Normally, the gap between the base fabric surface of the rubbing cloth I2 and the coating film 100 for alignment film is set to 0.5 to 0.5 using a gap gauge, for example.
The height adjustment mechanism 20 adjusts the height to 1 mm. Then, stage 3 on which the glass substrate l was placed
If the stage transport mechanism I5 is driven by the stage transport mechanism power supply/control unit 16 and the stage 3 is sent below the rotating rubbing cloth winding roller 11, the friction caused by the pile 120 of the rubbing cloth 12 will cause the glass substrate to l
An alignment film 101 is formed on the surface of the upper coating film 100 for alignment film.

[Problem to be solved by the invention]

However, the above-mentioned conventional alignment film rubbing apparatus adjusts the gap between the base cloth surface of the rubbing cloth 12 and the alignment film coating film 100 to a height of 0.5 to 1 mm using a gap gauge, for example. It is difficult to easily perform this adjustment because it is a heavy device, and due to variations in the thickness of the rubbing cloth 12 and errors caused by wear, the alignment film 101 may have variations in orientation. For example, if the rubbing is too weak, rubbing streaks will occur, resulting in streak-like display defects, while if the rubbing is too strong, rubbing will result in unevenness, resulting in display unevenness with partial brightness and darkness.These issues need to be resolved. there were.

[Means to solve the problem]

The above problem is solved by a roller support rack lO, a rubbing cloth wrapping roller 11 rotatably attached to the roller support rack lO, a rubbing cloth 12 wound around the rubbing cloth wrapping roller 11, and a rubbing cloth wrapping roller 11 rotatably attached to the roller support rack lO, Roller drive devices 13a, 13 that rotate the cloth wrapping roller ll
b, a pedestal 14 on which the roller support rack IO is placed and fixed, and a stage transport mechanism 15 attached to the pedestal 14.
a, 15b, a power supply/control device 16 for driving the stage transport mechanism 15, and a stage for mounting a glass substrate l, which is transported by the stage transport mechanism 15 below the rubbing cloth wrapping roller 11 in parallel to the roller surface. 3, a surface plate 2 on which a glass substrate l is mounted, which is movably provided on the upper surface of the stage 3, and the glass substrate l is brought into contact with the rubbing cloth 12 with a predetermined pressure;
The problem can be solved by a rubbing device for liquid crystal display element alignment film, which includes at least a pressure transmission mechanism 4 that moves the surface plate 2 up and down, and a pressure detection/control device 5 that controls the pressure applied to the pressure transmission mechanism 4. can.

[Effect]

In the rubbing device for an alignment film of the present invention, the gap between the base fabric surface of the rubbing cloth 12 and the coating film 100 for an alignment film is detected by the pressure transmission mechanism 4 and the pressure detection/control device 5 using a pressure medium such as compressed air. Coating film 1 for alignment film on glass substrate l
00 is controlled so that it always contacts the surface of the rubbing cloth 12 with a constant pressure, an alignment film 101 having uniform and stable alignment performance can be obtained.

〔Example〕

FIG. 1 is a diagram showing an embodiment of the present invention.

Figure (a) is a front view, and figure (b) is a side view.

In the figure, 3 is a stage, and a pressure transmission mechanism 4 is attached to it.
is provided, and a surface plate 2 on which a glass substrate 1 is placed is fixedly placed at the tip thereof. Reference numeral 5 denotes a pressure detection/control device, for example, a pressure sensor 52 detects the pressure of the pressure medium sent from the pressure vessel 50 to the pressure transmission mechanism 4;
The pressure control bubble 51 of the pressure vessel 50 is automatically controlled to open and close.

Note that the same reference numerals are given to the same parts as those explained in the various countries of the conventional example, and the explanation of the same parts will be omitted.

FIG. 2 is a diagram showing the main parts of the apparatus according to the present invention. For example, the figure shows a case where the surface plate 2 is fixed by two pressure transmission mechanisms 4.

In this example, compressed air is used as the pressure medium, and the pressure transmission mechanism 4 includes, for example, a cylinder 40 and a piston 41.
It is composed of separate piping, respective pressure control valves 51a, 51b, and pressure detectors 52a, 5.
2b, it is connected to a pressure vessel 50 filled with compressed air.

Rather than measuring the gap between the base cloth surface of the rubbing cloth 12 and the coating film 100 for alignment film, the optimum contact pressure between the two is determined in advance, and the pressure transmission mechanism 4 is adjusted so as to always maintain that value. The height, that is, the height of the surface plate 2 is automatically controlled.

In order to make it possible to move the stage 3 from side to side, a flexible curled coil-shaped part may be provided in a part of the compressed air piping. It may be moved.

With the stage 3 in place, the roller support frame IO supporting the rubbing cloth take-up roller 11 is separated from the frame 14 and moved on the frame I4, and the coating film 100 for alignment film on the glass substrate l is rubbed. You can do it like this. In this case, there is no need to move the pressure vessel 50 and the piping section, which is advantageous.

Although compressed air was used as the pressure medium in the above embodiment, other gases may be used, or a hydraulic system using oil may be used. Furthermore, the device of the invention may be implemented using a mechanical spring mechanism.

Further, it is easily understood from the spirit of the present invention that the pressure transmission mechanism 4 for moving the surface plate 2 up and down can be constructed by combining a motor and a screw feeding mechanism.

In the above embodiment, two pressure transmission mechanisms 4 are illustrated, but it is possible to use only one pressure transmission mechanism 4 depending on the size of the glass substrate used, or it is of course possible to arrange three or more pressure transmission mechanisms 4 for stabilization. It is.

Furthermore, it goes without saying that materials, mechanisms, configurations, etc., other than those described above, or combinations thereof, may be used as appropriate, as long as they comply with the spirit of the present invention.

〔Effect of the invention〕

As explained above, according to the rubbing device for alignment film of the present invention, the base fabric surface of the rubbing cloth 12 and the coating film 100 for alignment film
The gap between the pressure transmission mechanism 4 and the pressure detection/control device 5
As a result, the coating film 100 for alignment film on the glass substrate 1 is controlled so as to always come into contact with the surface of the rubbing cloth 12 with a constant pressure, so that the alignment film 101 has uniform and stable alignment performance. This greatly contributes to improving the performance and quality of liquid crystal display devices.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an example device of the present invention, FIG. 2 is a diagram showing main parts of an example device of the present invention, FIG. 3 is a diagram showing an example of the basic configuration of a liquid crystal display device, and FIG. 4 is a rubbing FIG. 5 is a diagram illustrating an example of a conventional rubbing device. In the figure, 1 is a glass substrate, 2 is a surface plate, 3 is a stage, is a pressure transmission mechanism, is a pressure detection/control device, 0 is a roller support rack, ■ is a rubbing cloth wrapping roller, 2 is a rubbing cloth, 3 (13a) , 13b) are roller drive devices, 4 is a pedestal, 5 (15a, 15b) is a stage transport mechanism, 6 is a stage transport mechanism power supply/control device, 00 is a coating film for an alignment film, and OI is an alignment film. (I) Masaru, dwa's whistle $eSJ'l'N!4F'l*l"'FfpKfTI0
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Claims (1)

[Claims] A roller support rack (10), a rubbing cloth wrapping roller (11) rotatably attached to the roller support rack (10), and a rubbing cloth wrapping roller (11) wrapped around the rubbing cloth wrapping roller (11). Rubbing cloth (
12), a roller drive device (13a, 13b) for rotating the rubbing cloth wrapping roller (11), and a pedestal (14) for mounting and fixing the roller support frame (10).
and a stage transport mechanism attached to the pedestal (14).
15a, 15b), a power supply/control device (16) that drives the stage transport mechanism (15), and a stage transport mechanism (15) that moves the rubbing cloth wrapping roller (11) downwardly and parallel to the roller surface. A stage (3) for mounting the glass substrate (1) to be transported; a surface plate (2) on which the glass substrate (1) is placed, which is provided on the top surface of the stage (3) so as to be movable up and down; a pressure transmission mechanism (4) that moves the surface plate (2) up and down so that the glass substrate (1) contacts the rubbing cloth (12) with a predetermined pressure; A rubbing device for a liquid crystal display element alignment film, comprising at least a pressure detection/control device (5) for controlling pressure.