US20080261495A1

US20080261495A1 - Alighment apparatus and alignment method thereof

Info

Publication number: US20080261495A1
Application number: US12/148,659
Authority: US
Inventors: Jung-Min Kuo; Hung-Sheng Cho; Kun-Hsing Hsiao
Original assignee: Innolux Display Corp
Current assignee: Innolux Corp
Priority date: 2007-04-20
Filing date: 2008-04-21
Publication date: 2008-10-23
Also published as: TW200842463A; TWI350414B

Abstract

An exemplary alignment apparatus (20) includes a supporting member (24), a conveyor (25), and a high-pressure fluid generator (21). The supporting member is configured for supporting a substrate (23) having an alignment layer (26). 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 onto a surface of the alignment layer of the substrate to form an alignment surface. Because the alignment apparatus includes the high-pressure fluid generator which can eject high-pressure fluid to impact the surface of the alignment layer in order to form an alignment surface, no debris is introduced. Therefore, the substrates processed by the alignment apparatus can have improved quality and reliability.

Description

BACKGROUND

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.

SUMMARY

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.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram of an alignment apparatus according to a first embodiment of the present invention, also showing two glass substrates, and showing aspects of operation of the alignment apparatus.

FIG. 2 is a flowchart summarizing an exemplary alignment method using the alignment apparatus of FIG. 1.

FIG. 3 is a diagram of an alignment apparatus according to a second embodiment of the present invention, also showing two glass substrates, and showing aspects of operation of the alignment apparatus.

FIG. 4 is a diagram of an alignment apparatus according to a third embodiment of the present invention, also showing two glass substrates, and showing aspects of operation of the alignment apparatus.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Referring to FIG. 1, an alignment apparatus 20 according to a first embodiment of the present invention is shown. The alignment apparatus 20 includes a high-pressure fluid generator 21, a plurality of supporting plates 24, and a conveyor 25 configured to move along a predetermined direction. The supporting plates 24 are positioned on the conveyor 25, and each supporting plate 24 supports a glass substrate 23. The glass substrate 23 includes an unfinished alignment layer 26 formed thereon. The high-pressure fluid generator 21 includes a fluid knife 22. The fluid knife 22 is configured to blow high-pressure air or gas onto a surface of the alignment layer 26. The impact force generated by the high-pressure air or gas makes molecules of the surface of the alignment layer 26 homogeneously align. Thus the finished alignment layer 26 provides a directional template for the alignment of liquid crystal molecules in contact with the surface after the glass substrate 23 is assembled into a liquid crystal display.
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 FIG. 2, a flowchart summarizing an exemplary alignment method using the alignment apparatus 20 is shown. The alignment method is as follows:
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 FIG. 3, an alignment apparatus 30 according to a second embodiment of the present invention is shown. The alignment apparatus 30 includes a high-pressure fluid generator 31, a plurality of supporting plates 34, a conveyor 35 configured to move along a predetermined direction, and a plurality of suction units 37. The supporting plates 24 are positioned on the conveyor 35, and each supporting plate 34 supports a glass substrate 33. The glass substrate 33 includes an unfinished alignment layer 36 formed thereon. The high-pressure fluid generator 31 includes a fluid knife 32. The fluid knife 32 is configured to blow high-pressure air or gas onto a surface of the alignment layer 36. Each supporting plate 34 has a suction unit 37 positioned along a peripheral portion thereof. The suction unit 37 surrounds the glass substrate 33 positioned on the supporting plate 34. The suction unit 37 is configured to guide air or gas flows around the glass substrate 33, in order to prevent air or gas flows reflected by the supporting plate 34 from interfering with the high-pressure air or gas.
Referring to FIG. 4, an alignment apparatus 40 according to a third embodiment of the present invention is similar to the alignment apparatus 20 of the first embodiment. However, the alignment apparatus 40 further includes an ultrasonic generator 48. The ultrasonic generator 48 is configured to generate and transmit ultrasonic waves to impact an unfinished surface of an alignment layer 46 of a glass substrate 43. A fluid knife 42 ejects high-pressure air or gas to impact the unfinished surface of the alignment layer 46 of the glass substrate 43.
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.

Claims

1. An alignment apparatus for treating an unfinished surface, the alignment apparatus comprising:

a supporting member configured for supporting a substrate having an alignment layer;

a conveyor configured for conveying the supporting member along a predetermined direction; and

a high-pressure fluid generator configured for generating and ejecting high-pressure fluid to impact a surface of the alignment layer of the substrate to form an alignment surface.

2. The alignment apparatus in claim 1, wherein the high-pressure fluid generator comprises a fluid knife, the fluid knife configured to eject high-pressure fluid onto the surface of the alignment layer.

3. The alignment apparatus in claim 2, wherein the fluid knife of the high-pressure fluid generator is rotatable such that an angle between the fluid knife and the substrate is adjustable.

4. The alignment apparatus in claim 1, further comprising a suction unit provided along a peripheral portion of supporting member, the suction unit surrounding the substrate and configured for guiding fluid flows around the substrate.

5. The alignment apparatus in claim 1, wherein the high-pressure fluid comprises at least one of high-pressure gas and high-pressure liquid.

6. The alignment apparatus in claim 5, wherein the high-pressure gas comprises one of nitrogen and air.

7. The alignment apparatus in claim 5, wherein the high-pressure liquid comprises one of purified water and deionized water.

8. The alignment apparatus in claim 5, further comprising an ultrasonic generator, the ultrasonic generator configured for generating and transmitting ultrasonic waves to impact the surface of the alignment layer of the substrate.

9. The alignment apparatus in claim 2, wherein the fluid knife is made of stainless steel.

10. The alignment apparatus in claim 1, wherein the substrate is a glass substrate.

11. The alignment apparatus in claim 1, wherein the material of the alignment layer is selected from the group consisting of polyimide and polyamic acid.

12. An alignment method for treating an unfinished surface, the method using an alignment apparatus, the alignment apparatus comprising a supporting member, a conveyor, and a high-pressure fluid generator, the method comprising:

providing a substrate having an alignment layer formed thereon;

placing the substrate on the supporting member;

the conveyor conveying the supporting member along a predetermined direction; and

the high-pressure fluid generator generating and ejecting high-pressure fluid to impact a surface of the alignment layer in order to form an alignment surface.

13. The alignment method in claim 12, wherein a thickness of the alignment layer is in the range from 500˜1000 angstroms.

14. The alignment method in claim 12, wherein the material of the alignment layer is selected from the group consisting of polyimide and polyamic acid.

15. The alignment method in claim 12, wherein the high-pressure fluid comprises at least one of high-pressure gas and high-pressure liquid.

16. The alignment method in claim 15, wherein the high-pressure gas comprises one of nitrogen and air.

17. The alignment method in claim 15, wherein the high-pressure liquid comprises one of purified water and deionized water.

18. The alignment method in claim 15, wherein the alignment apparatus further comprises an ultrasonic generator, and the method further comprises:

the ultrasonic generator generating and transmitting ultrasonic waves to impact the surface of the alignment layer while the high-pressure fluid generator generates and ejects high-pressure fluid to impact the surface of the alignment layer.

19. An alignment apparatus for treating an unfinished surface, the alignment apparatus comprising:

a supporting member configured for supporting a glass substrate having an unfinished alignment layer;

a high-pressure fluid generator configured for generating and ejecting high-pressure fluid to impact a surface of the alignment layer of the substrate to make molecules of the surface of the alignment layer homogeneously align.