Patent Application
20080261495
1. Field of the Invention
The present invention relates to alignment apparatuses such as those used to make alignment layers of liquid crystal displays. More particularly, the invention relates to an alignment apparatus including a high-pressure fluid generator which is used to treat a surface of an alignment layer, and to an alignment method using an alignment apparatus.
2. General Background
A typical liquid crystal display (LCD) is capable of displaying a clear and sharp image through thousands or even millions of pixels that make up the complete image. The liquid crystal display has thus been applied to various electronic equipment in which messages or pictures need to be displayed, such as mobile phones and notebook computers.
In the manufacture of a typical LCD, an essential requirement is the alignment of liquid crystal molecules on a surface of an alignment layer (hereinafter “alignment surface”) of the LCD. The liquid crystal molecules are placed on the alignment surface prior to the formation of the LCD cell that contains the alignment layer and the liquid crystal molecules. The most widely used method for producing the alignment surface is to coat a film, such as a polyimide film, on a base layer such as a glass substrate. The polyimide film forms the base material of the alignment layer. The surface of the polyimide film is then rubbed with a velvet cloth. This rubbing process realigns the polyimide surface to form the alignment surface. The alignment surface provides a directional template for the alignment of the liquid crystal molecules in contact with the surface.
The rubbing method has been the process of choice for as much as the last three decades in order to provide alignment surfaces required for LCDs. However, the rubbing process introduces debris from the cloth into an otherwise unpolluted clean room environment. The rubbing process can also lead to electrostatic charge buildup. If electrostatic discharge (ESD) occurs, this can destroy transistors located on the glass substrate below the polyimide surface. These transistors are essential for the operation of the LCD. Therefore it is especially important that forming the alignment surface does not threaten the viability of these transistors.
What is needed, therefore, is an alignment apparatus for producing an alignment surface which can overcome or at least mitigate the above-described problems. What is also needed is an alignment method associated with such alignment apparatus.
In one preferred embodiment, an alignment apparatus includes a supporting member, a conveyor, and a high-pressure fluid generator. The supporting member is configured for supporting a substrate having an alignment layer. The conveyor is configured for conveying the supporting member along a predetermined direction. The high-pressure fluid generator is configured for generating and ejecting high-pressure fluid to impact a surface of the alignment layer of the substrate to form an alignment surface.
Other novel features and advantages will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.
Referring to
The fluid knife 22 of the high-pressure fluid generator 21 can be rotated to adjust an angle between the fluid knife 22 and the glass substrate 23. Thereby, an alignment direction of the alignment layer 26 can be configured according to requirements. The fluid knife 22 can for example be made of stainless steel, which has high hardness and strength. The high-pressure gas ejected by the fluid knife 22 can for example be nitrogen or air. When the fluid knife 22 is configured to blow high-pressure air, it is known as an air knife.
Because the alignment apparatus 20 includes the high-pressure fluid generator 21 which can blow high-pressure air or gas to impact the surface of the alignment layer 26 in order to form an alignment surface, no debris is introduced. Thus, unlike with a conventional rubbing process, pollution of an associated clean room environment and electrostatic charge buildup can be completely avoided. Therefore, the glass substrates 23 processed by the alignment apparatus 20 have improved quality and reliability.
Referring to
Step S1, a glass substrate 23 is provided. The glass substrate 23 includes an unfinished alignment layer 26 coated thereon. A thickness of the alignment layer 26 is in the range from 500˜1000 angstroms. The material of the alignment layer 26 can for example be polyimide or polyamic acid.
Step S2, the glass substrate 23 is placed on one of the supporting plates 24 which are positioned on the conveyor 25.
Step S3, the conveyor 25 conveys the supporting plate 24 together with the glass substrate 23 along a predetermined direction. The conveyor 25 moves at a constant speed.
Step S4, while the glass substrate 23 is moving, the fluid knife 22 of the high-pressure fluid generator 21 blows high-pressure air or gas onto a surface of the alignment layer 26 of the glass substrate 23 to form an alignment surface.
Referring to
Referring to
Further or alternative embodiments may include the following:
In a first example, the fluid knife 22 of the high-pressure fluid generator 21 is configured to eject high-pressure liquid to impact the unfinished surface of the alignment layer 26 of the glass substrate 23. In such case, the supporting plates 24 can be slightly inclined such that residual liquid on the glass substrates 23 can be drained off. The high-pressure liquid can for example be purified water or deionized water.
In a second example, the fluid knife 22 of the high-pressure fluid generator 21 is configured to simultaneously eject high-pressure gas and high-pressure liquid to impact the unfinished surface of the alignment layer 26 of the glass substrate 23.
In a third example, the ultrasonic generator 48 generates and transmits ultrasonic waves to impact an unfinished surface of the alignment layer 46 of the glass substrate 43, and the fluid knife 42 simultaneously ejects high-pressure liquid to impact the unfinished surface of the alignment layer 46 of the glass substrate 43.
In a fourth example, the ultrasonic generator 48 generates and transmits ultrasonic waves to impact an unfinished surface of the alignment layer 46 of the glass substrate 43, and the fluid knife 42 simultaneously ejects high-pressure gas and high-pressure liquid to impact the unfinished surface of the alignment layer 46 of the glass substrate 43.
It is to be further understood that even though numerous characteristics and advantages of the present embodiments have been set out in the foregoing description, together with details of the structures and functions of the embodiments, the disclosure is illustrative only; and that changes may be made in detail, especially in matters of shape, size and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.
| Number | Date | Country | Kind |
|---|---|---|---|
| 96113934 | Apr 2007 | TW | national |
