JP2537897B2 - Rubbing processing device for alignment film for liquid crystal display - Google Patents

Description

The present invention relates to a rubbing treatment apparatus for an alignment film for a liquid crystal display used for manufacturing a liquid crystal display panel, and a rubbing roll and an alignment film for rubbing the alignment film on the surface of a liquid crystal display substrate. The alignment film for liquid crystal display, which makes it easy to detect and control the rubbing pressure by making it possible to electrically measure the contact pressure with the rubbing treatment device, was placed on the substrate support base. A device for rubbing an alignment film provided on a surface of a liquid crystal display substrate with a rubbing roll, wherein the rubbing roll has a structure in which a conductive rubbing material is attached to an outer peripheral surface of the liquid crystal display substrate. It has the same thickness as the total thickness, and it is detected by the contact resistance when the conductive surface of the monitor substrate for measuring the rubbing pressure with the surface as the conductive surface is brought into contact with the conductive rubbing material. The rubbing roll on the basis of the rubbing pressure to be,
Alternatively, a mechanism for adjusting the rubbing pressure by moving either of the substrate supports to make the gap between them variable is provided.

[Industrial applications]

The present invention relates to a rubbing treatment device for an alignment film for liquid crystal display used for manufacturing a liquid crystal display panel.

Liquid crystal display panels are being widely used for calculators, televisions, and displays for OA equipment.

In such a liquid crystal display panel, rubbing treatment of an alignment film for aligning liquid crystal molecules in a certain arrangement is one of the important factors that influence the quality of liquid crystal display.

Therefore, to obtain a liquid crystal display panel with high display quality,
It is required that uniform rubbing treatment can be realized with good reproducibility by controlling the rubbing pressure during rubbing treatment on the alignment film to be constant.

[Conventional technology]

In a twisted nematic liquid crystal display panel, etc., the display is performed by utilizing the phenomenon that liquid crystal molecules are aligned in the rubbing direction when a drive voltage is applied. As an example, as shown in FIG. 3, for example, a liquid crystal display substrate 1 in which an alignment film 3 of polyimide or the like is formed on a glass substrate 2 provided with a transparent display electrode (not shown) is mounted on a substrate support 11 The upper surface of the alignment film 3 is placed on the roll body 13 for example.
The rubbing roll 12 is provided with a rubbing material 14 such as a fiber such as nylon or a cotton cloth on the outer peripheral surface thereof, and the rubbing roller 12 is rotated while rubbing in a certain direction, so-called rubbing.

[Problems to be solved by the invention]

By the way, in such a rubbing treatment step, the contact pressure of the rubbing material 14 such as nylon or the like in the rubbing roll 12 or the cotton rubbing material 14 to the alignment film 3 is appropriately controlled, and a uniform rubbing pressure is constantly applied. It is important to be able to process.

Therefore, as a method for adjusting the pressure during rubbing to a constant level, conventionally, a method using a pressure sensor or a servomotor is used to cause power loss caused by rotational friction when the rubbing roll 12 and the alignment film 3 come into contact with each other. Was adjusted by the method of detecting

However, the former method has a problem that the contact pressure between the rubbing material 14 of the rubbing roll 12 and the alignment film 3 is extremely small, and it is difficult to obtain a highly sensitive sensor corresponding thereto. In the latter method, the structure for detecting is complicated and expensive, and the power loss to be detected is small, so that it is easily affected by noise from others and it is difficult to adjust the rubbing pressure accurately. was there.

In view of the conventional drawbacks described above, the present invention detects the rubbing pressure by rubbing the alignment film on the surface of the liquid crystal display substrate so that the contact pressure between the rubbing roll and the alignment film can be electrically measured. It is an object of the present invention to provide a novel rubbing treatment apparatus for an alignment film for liquid crystal display, which is easily controlled.

[Means for solving problems]

The present invention, in order to achieve the above objects, a rubbing roll for rubbing the alignment film on the surface of the liquid crystal display substrate disposed on the substrate support, a configuration in which a conductive rubbing material is attached to the outer peripheral surface, It has a thickness equal to the total thickness of the liquid crystal display substrate, and by the contact resistance when the conductive rubbing material is brought into contact with the conductive surface of the monitor substrate for measuring the rubbing pressure whose surface is a conductive surface. Based on the detected rubbing pressure, either the rubbing roll or the substrate support is moved so that the gap between the two is made variable to adjust the rubbing pressure.

[Work]

The apparatus for rubbing an alignment film for a liquid crystal display of the present invention, the conductive rubbing material of the rubbing roll and the conductive film on the surface of the monitor substrate 23 contact each other as shown in the principle explanatory diagram by the equivalent circuit of FIG. The conductive roll main body 27 of the roll and the conductive film on the surface of the monitor substrate 23 are electrically connected. When the contact pressure of the rubbing roll on the surface of the monitor substrate 23 increases, the contact area between the conductive rubbing material of the rubbing roll and the surface of the monitor substrate 31 increases.

As a result, the conductive roll body 27 and the monitor substrate 23 are
The resistance R between the surface and the conductive film decreases, and the contact resistance portion functions as a variable resistance by increasing or decreasing the contact pressure.

Therefore, by taking the correspondence relationship between the changing resistance value and the alignment state of the liquid crystal by the alignment film after the rubbing treatment, the contact resistance value corresponding to the proper rubbing pressure can be grasped, and the rubbing treatment can be performed prior to the rubbing treatment. Conductive roll body
It becomes possible to adjust the rubbing pressure by monitoring the contact resistance value between the 27 and the conductive film on the surface of the monitor substrate 23.
The rubbing treatment of the alignment film can be performed at a constant and appropriate rubbing pressure.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 2 is a configuration diagram conceptually showing one embodiment of a rubbing treatment apparatus for an alignment film for liquid crystal display according to the present invention.

In the figure, 21 is a substrate support base that can be finely moved in the vertical direction by a fine adjustment unit 22, and 23 is an insulating substrate 24 made of glass or the like.
A monitor substrate having a conductive film 25 made of In ₂ O ₃ or the like deposited thereon, and 26 a roll body 27 made of aluminum (Al) or the like.
This is a rubbing roll in which a conductive rubbing material 28 such as rayon containing carbon is wound around the outer peripheral surface of the.

Further, as the rubbing pressure adjusting mechanism, the fine adjustment unit 22,
It comprises a resistance measuring unit 29 and a rubbing pressure control circuit 30.

In this device, prior to rubbing the alignment film on the surface of the liquid crystal display substrate, the monitor substrate 23 is placed on the substrate support 21, and the substrate support 21 is slightly moved upward by the fine adjustment unit 22 to face it. The conductive rubbing material 28 of the rubbing roll 26 is brought into contact with the conductive film 25 of the monitor substrate 23, and a constant voltage is applied between the conductive film 25 of the monitor substrate 23 and the roll body 27 of the rubbing roll 26. Perform rubbing operation.

At this time, the resistance measuring unit 29 measures the conductive film of the monitor substrate 23.
The contact resistance value between the conductive rubbing material 28 of the rubbing roll 26 and the rubbing roll 26 is measured, and the measured resistance signal is input to the rubbing pressure control circuit 30. The rubbing pressure control circuit 30
Then, based on the contact resistance value corresponding to an appropriate rubbing pressure that has been experimentally correlated from the measured resistance signal, an appropriate height position of the substrate support base 21 is calculated, and the fine adjustment unit 22 is thereby calculated. Controlling the substrate support
Finely move 21 up and down to adjust the rubbing pressure properly.

Incidentally, the diameter of the roll body 27 of the rubbing roll 26 in this case is 52 mmφ, the length is 450 mm, the resistance value is 10 ³ to 10 ⁴ Ωcm,
The conductive film 25 of the monitor substrate 23 has an area of 100 mm × 100 mm, a film thickness of 500Å, and a sheet resistance of 50Ω □.

Then, when the rubbing roll 26 is rotated at 500 rpm with respect to the conductive film 25 of the monitor substrate 23 to change the rubbing pressure, the contact resistance value changes from 500 kΩ to several MΩ. Moreover, the contact resistance value corresponding to an appropriate rubbing pressure is 1 to 1.2 MΩ from the experimental result, and the measurement adjustment is possible.

After that, the monitor substrate 23 on the substrate support 21 in which the rubbing pressure is properly adjusted, and the liquid crystal display substrate in which an alignment film such as polyimide is formed on the transparent display electrode is replaced, and the alignment film is replaced. By performing the rubbing treatment on the surface, it is possible to always perform the rubbing treatment at a constant and appropriate rubbing pressure.

In the above embodiment, an example of adjusting the rubbing pressure by finely moving the substrate support table up and down has been described.
The present invention is not limited to this example. For example, the rubbing pressure may be adjusted by finely moving the rubbing roll up and down, and similar results can be obtained.

〔The invention's effect〕

As is clear from the above description, according to the rubbing treatment apparatus for the alignment film for liquid crystal display according to the present invention, it is possible to adjust the proper rubbing pressure easily and with good reproducibility, and always keep a constant and proper value. It has an excellent advantage that the rubbing treatment can be performed with a rubbing pressure, and a liquid crystal display substrate having a good alignment performance can be easily obtained, and the manufacturing yield of the liquid crystal display panel can be improved.

[Brief description of drawings]

FIG. 1 is an equivalent circuit diagram for explaining the principle of the present invention, FIG. 2 is a configuration diagram conceptually showing one embodiment of a rubbing treatment apparatus for an alignment film for liquid crystal display according to the present invention, and FIG. It is a block diagram for demonstrating the rubbing process of the alignment film for liquid crystal displays. In FIG. 1 and FIG. 2, 21 is a substrate support, 22 is a fine adjustment unit, 23 is a monitor substrate,
24 is an insulating substrate, 25 is a conductive film, 26 is a rubbing roll, 27
Is a conductive roll body, 28 is a conductive rubbing material, 29 is a resistance measuring unit, and 30 is a rubbing pressure control circuit.

Claims (1)

(57) [Claims] 1. An apparatus for rubbing an alignment film provided on a surface of a liquid crystal display substrate arranged on a substrate support base with a rubbing roll, wherein the rubbing roll has a conductive rubbing material on an outer peripheral surface thereof. With the attached structure, the conductive surface and the conductive rubbing material of the monitor substrate for measuring the rubbing pressure having the same thickness as the total thickness of the liquid crystal display substrate and having the surface as the conductive surface are in contact with each other. Based on the rubbing pressure detected by the contact resistance at the time of making the rubbing roll, or a substrate support table is moved to adjust the rubbing pressure by varying the gap between them. A characteristic rubbing treatment apparatus for an alignment film for liquid crystal display.