U.S. patent application number 11/554682 was filed with the patent office on 2007-03-15 for in-line system and method for manufacturing liquid crystal display.
Invention is credited to Dae-Ho Choo, Yong-Joon Kwon, Sang-Jun Lee.
Application Number | 20070056686 11/554682 |
Document ID | / |
Family ID | 19711055 |
Filed Date | 2007-03-15 |
United States Patent
Application |
20070056686 |
Kind Code |
A1 |
Choo; Dae-Ho ; et
al. |
March 15, 2007 |
IN-LINE SYSTEM AND METHOD FOR MANUFACTURING LIQUID CRYSTAL
DISPLAY
Abstract
An in-line system for fabricating a liquid crystal display
includes a sealer coating unit for coating a sealer onto a first
substrate with a plurality of liquid crystal display cell regions a
liquid crystal injection unit for dropping a liquid crystal onto
the first substrate coated with the sealer, and an assembly unit
for assembling the first substrate with the second substrate, A
sealer hardening unit hardens the sealer interposed between the
first and the second substrate to thereby assemble the first and
the second substrate with each other. A substrate cutting unit cuts
the first and the second substrates along cutting lines through
illuminating a laser beam along the cutting lines such that the
first and the second substrates are severed into the liquid crystal
display cell regions.
Inventors: |
Choo; Dae-Ho; (Suwon-city,
KR) ; Lee; Sang-Jun; (Suwon-city, KR) ; Kwon;
Yong-Joon; (Seoul, KR) |
Correspondence
Address: |
Frank Chau, Esq.;F. CHAU & ASSOCIATES, LLP
Suite 501
1900 Hempstead Turnpike
East Meadow
NY
11554
US
|
Family ID: |
19711055 |
Appl. No.: |
11/554682 |
Filed: |
October 31, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10762436 |
Jan 22, 2004 |
7138030 |
|
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11554682 |
Oct 31, 2006 |
|
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10108045 |
Mar 27, 2002 |
6710843 |
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10762436 |
Jan 22, 2004 |
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Current U.S.
Class: |
156/272.8 ;
156/250; 156/291; 156/292; 156/498; 156/523; 156/524; 156/526;
156/578 |
Current CPC
Class: |
Y10T 156/1348 20150115;
Y10T 156/1798 20150115; G02F 1/13392 20130101; Y10T 156/1052
20150115; Y10T 156/1085 20150115; G02F 1/133351 20130101; G02F
1/1341 20130101; Y10T 156/1374 20150115; Y10T 156/1317 20150115;
G02F 1/1303 20130101; Y10T 156/1352 20150115; Y10T 156/1361
20150115; Y10T 225/304 20150401; Y10T 156/1744 20150115 |
Class at
Publication: |
156/272.8 ;
156/578; 156/523; 156/524; 156/526; 156/498; 156/291; 156/292;
156/250 |
International
Class: |
B32B 38/04 20060101
B32B038/04; B32B 37/12 20060101 B32B037/12; B32B 38/00 20060101
B32B038/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 19, 2001 |
KR |
2001-34761 |
Claims
1. An in-line system for fabricating a liquid crystal display, the
in-line system comprising: a spacer dispersing unit for dispersing
spacers onto at least one of first and second substrates with a
plurality of liquid crystal display cell regions; a sealer coating
unit for coating a sealer onto the first substrate; a liquid
crystal injection unit for dropping liquid crystal onto the first
substrate coated with the sealer; an assembly unit for assembling
the first substrate with the second substrate; a sealer hardening
unit for hardening the sealer interposed between the first and the
second substrate to thereby join the first and the second
substrate; and a substrate cutting unit for cutting the first and
the second substrates along cutting lines through illuminating a
laser beam along the cutting lines such that the first and the
second substrates are severed into the liquid crystal display cell
regions.
2. The in-line system of claim 1 wherein the substrate cutting unit
comprises: a laser for pre-heating the first and the second
substrates along the cutting lines; a laser transporter for fixing
or transporting the laser; and a cooling agent spraying unit for
cooling the pre-heated first and second substrates along the
cutting lines.
3. The in-line system of claim 2 wherein the substrate cutting unit
further comprises a substrate transporter for fixing, rotating or
transporting the first and the second substrates.
4. The in-line system of claim 2, wherein the cooling agent
spraying unit is mounted on the laser transporter.
5. The in-line system of claim 1 wherein the spacer dispersing
unit, the sealer coating unit, the liquid crystal injection unit,
the assembly unit, the sealer hardening unit and the substrate
cutting unit are designed to be in-line.
6. The in-line system of claim 1 further comprising first and
second preliminary alignment units for aligning the first and the
second substrates with each other before the assembling, and a heat
treatment unit for heat-treating the liquid crystal.
7. A method of fabricating a liquid crystal display, the method
comprising the steps of: dispersing spacers onto at least one of
first and second substrates with a plurality of liquid crystal
display cell regions; coating a sealer onto the first substrate;
dropping a liquid crystal onto the first substrate; assembling the
first and the second substrates to join with each other; hardening
the sealer interposed between the first and the second substrates;
and cutting the first and the second substrates along cutting lines
using a laser such that the first and the second substrates are
severed into a plurality of liquid crystal display cell
regions.
8. The method of claim 7 wherein the step of cutting the first and
the second substrates further comprises the steps of: pre-heating
the first and the second substrates along the cutting lines through
illuminating a laser beam along the cutting lines; cooling the
first and the second substrates along the cutting lines through
spraying a cooling agent along the cutting lines to thereby form a
crack; and propagating the crack along the cutting lines.
9. An in-line system for fabricating a liquid crystal display, the
in-line system comprising: means for dispersing spacers between
first and second substrates; means for joining the first and second
substrates to form a gap; means for injecting liquid crystal onto
the gap; and means for cutting the first and the second substrates
along cutting lines such that the first and the second substrates
are severed into the liquid crystal display cell regions.
10. The in-line system of claim 9 wherein the means for cutting
comprises: a laser for pre-heating the first and the second
substrates along the cutting tines; a laser transporter for fixing
or transporting the laser; and a cooling agent spraying unit for
cooling the pre-heated first and second substrates along the
cutting lines.
11. The in-line system of claim 9 wherein the means for joining
comprises a sealer coating unit and a sealer hardening unit, the
sealer coating unit for coating at least one of the first and
second substrates with a sealer and the sealer hardening unit for
hardening the sealer.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a Continuation of U.S. patent
application Ser. No. 10/762,436 filed on Jan. 22, 2004, which is a
Continuation of U.S. patent application Ser. No. 10/108,045 filed
on Mar. 27, 2002, now U.S. Pat. No, 6,710,843 and which claims
priority to Korean Patent Application No. 2001-34761 filed Jun. 19,
2001 in the Korean Intellectual Property Office (KIPO), all of
which are fully incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] (a) Field of the Invention
[0003] The present invention relates to an in-line system for a
liquid crystal display, and a method of fabricating a liquid
crystal display using the same.
[0004] (b) Description of the Related Art
[0005] Generally, the fabrication of a liquid crystal display
involves processes of fabricating an array substrate where wiring
line patterns and switching circuits (in the case of an active
matrix type) are formed on a glass substrate, a liquid crystal
display cell process where alignment treatment, spacer formation
and injection of a liquid crystal between the array substrate and
an opposing substrate are made, and a module process where
attachment of driver ICs and mounting of a backlight are made.
[0006] A plurality of liquid crystal display cell regions are
simultaneously formed at a mother glass in the array substrate
fabrication process. The plurality of liquid crystal display cell
regions are severed from each other to form separate display units
through cutting in the liquid crystal display cell process,
[0007] In the liquid crystal display cell process, a vacuum
injection or a drop injection may be made to fill the cells with
liquid crystal.
[0008] With the vacuum injection, an alignment film is coated onto
the substrates to align the liquid crystal molecules, and then
surface-treated. Spacers are formed at one of the substrates to
maintain the cell gap in a constant manner, and a sealer with a
liquid crystal inlet hole is printed around the substrates. The
substrates are then aligned and assembled with each other through a
hot press process with a thermal-hardening sealer. After grooves
are formed at the substrates per a panel unit through scribing, the
substrates are severed from each other through impact cutting. The
respective panels are put into a vacuum vessel such that the liquid
crystal inlet hole of the sealer is dipped into a liquid crystal.
In this way, the liquid crystal is injected into the liquid crystal
display cell. Finally, the liquid crystal inlet hole is sealed such
that the injected liquid crystal is contained.
[0009] With the drop injection, an alignment film is coated onto
the substrates, and then surface-treated. Spacers are formed at one
of the substrates. After a sealer is formed around one of the
substrates in the shape of a closed curve, a liquid crystal is
dropped onto the substrate. The two substrates are aligned, and
assembled with each other by way of the sealer. Finally, the sealer
is hardened.
[0010] In the case of drop injection, as liquid crystal is
contained within the liquid crystal display cell while being
severed into unit cells through scribing, the characteristic of the
liquid crystal can deteriorate from loss of alignment force of the
alignment films and due to the impact to the substrates, and this
can result in poor display characteristics. To prevent such a
problem, the substrate severing may be completely made at the
groove formation process based on scribing by penetrating the
cutting blade through the substrates. In this case, the stress
applied to the substrates at the cutting becomes increased
Consequently, the possibility of deteriorating the display
characteristic of the liquid crystal display cell is increased and
production yield is decreased.
SUMMARY OF THE INVENTION
[0011] It is an object of the present invention to provide a system
and method of fabricating a liquid crystal display which prevents
deterioration of the display characteristic at the severing of the
substrates into unit cells, thereby enhancing production yield.
[0012] An in-line system for fabricating a liquid crystal display
is provided, the in-line system comprising a spacer dispersing unit
for dispersing spacers onto at least one of first and second
substrates with a plurality of liquid crystal display cell regions;
a sealer coating unit for coating a sealer onto the first
substrate; a liquid crystal injection unit for dropping liquid
crystal onto the first substrate coated with the sealer; an
assembly unit for assembling the first substrate with the second
substrate; a sealer hardening unit for hardening the sealer
interposed between the first and the second substrate to thereby
join the first and the second substrate; and a substrate cutting
unit for cutting the first and the second substrates along cutting
lines through illuminating a laser beam along the cutting lines
such that the first and the second substrates are severed into the
liquid crystal display cell regions,
[0013] Preferably, the substrate cutting unit comprises a laser for
pre-heating the first and the second substrates along the cutting
lines; a laser transporter for fixing or transporting the laser;
and a cooling agent spraying unit for cooling the pre-heated first
and second substrates along the cutting lines. The substrate
cutting unit further comprises a substrate transporter for fixing,
rotating or transporting the first and the second substrates. The
cooling agent spraying unit is mounted on the laser
transporter.
[0014] According to a preferred embodiment of the present
invention, the spacer dispersing unit, the sealer coating unit, the
liquid crystal injection unit, the assembly unit, the sealer
hardening unit and the substrate cutting unit are designed to be
in-line, The in-line system further comprising first and second
preliminary alignment units for aligning the first and the second
substrates with each other before the assembling, and a heat
treatment unit for heat-treating the liquid crystal.
[0015] A method is provided for fabricating a liquid crystal
display, the method comprising the steps of dispersing spacers onto
at least one of first and second substrates with a plurality of
liquid crystal display cell regions; coating a sealer onto the
first substrate; dropping a liquid crystal onto the first
substrate; assembling the first and the second substrates to join
with each other; hardening the sealer interposed between the first
and the second substrates; and cutting the first and the second
substrates along cutting lines using a laser such that the first
and the second substrates are severed into a plurality of liquid
crystal display cell regions.
[0016] The step of cutting the first and the second substrates
further comprises the steps of pre-heating the first and the second
substrates along the cutting lines through illuminating a laser
beam along the cutting lines; cooling the first and the second
substrates along the cutting lines through spraying a cooling agent
along the cutting lines to thereby form a crack; and propagating
the crack along the cutting lines.
[0017] According to another preferred embodiment of the present
invention an in-line system for fabricating a liquid crystal
display comprises means for dispersing spacers between first and
second substrates; means for joining the first and second
substrates to form a gap; means for injecting liquid crystal onto
the gap; and means for cutting the first and the second substrates
along cutting lines such that the first and the second substrates
are severed into the liquid crystal display cell regions.
[0018] The means for cutting comprises a laser for preheating the
first and the second substrates along the cutting lines; a laser
transporter for fixing or transporting the laser, and a cooling
agent spraying unit for cooling the pre-heated first and second
substrates along the cutting lines.
[0019] The means for joining comprises a sealer coating unit and a
sealer hardening unit the sealer coating unit for coating at least
one of the first and second substrates with a sealer and the sealer
hardening unit for hardening the sealer.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] A more complete appreciation of the invention, and many of
the attendant advantages thereof, will be readily apparent as the
same becomes better understood by reference to the following
detailed description when considered in conjunction with the
accompanying drawings in which like reference symbols indicate the
same or the similar components, wherein:
[0021] FIG. 1 is a plan view of a mother panel for a liquid crystal
display with a plurality of liquid crystal display cell regions
according to a preferred embodiment of the present invention;
[0022] FIG. 2A is an amplified view of the IIa portion of FIG.
1;
[0023] FIG. 2B is a cross sectional view of the liquid crystal
display taken along the IIb-IIb' line of FIG. 2;
[0024] FIG. 3 is a block diagram of an in-line system for
fabricating the liquid crystal display shown in FIG. 1; and
[0025] FIG. 4 illustrates the process of cutting the substrates of
the mother panel shown in FIG. 1 using a substrate cutting
unit.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0026] Preferred embodiments of this invention will be explained
with reference to the accompanying drawings.
[0027] FIG. 1 is a plan view of a mother panel for a liquid crystal
display with a plurality of liquid crystal display cells according
to a preferred embodiment of the present invention. FIG. 2A is an
amplified view of the IIa portion of FIG. 1, and FIG. 28 is a cross
sectional view of the liquid crystal display taken along the
IIb-IIb' line of FIG. 2A.
[0028] As shown in FIG. 1, four liquid crystal display cell regions
10a, 10b, 10c and 10d are formed at the mother panel 10. Cutting
lines A and B for severing the mother panel 10 into several liquid
crystal display unit cells are indicated with dotted lines. The
number of liquid crystal display cell regions to be formed at one
mother panel may be altered depending upon the dimension of the
mother panel and the liquid crystal display cell.
[0029] A plurality of pixel regions 26 are formed at an array
substrate 12 of the mother panel 10 in a matrix form while
collectively defining a display area 24. A thin film transistor
(not shown) is formed at each pixel region 26. The thin film
transistor is formed with a gate electrode, a drain electrode, and
a source electrode. The gate electrode of the thin film transistor
is connected to a gate line (not shown), and the drain electrode
thereof to a data line (not shown). The source electrode of the
thin film transistor is connected to a pixel electrode (not shown)
formed at the pixel region 26. The data lines and the gate lines
are connected to driving circuits (not shown) via terminals 14
formed at the outer periphery of the array substrate 12.
[0030] A color filter substrate 16 faces the array substrate 12.
The color filter substrate 16 is established to be smaller than the
array substrate 12 by the area of the terminals 14. A common
electrode (not shown) and color filters of red R, green G and blue
B (not shown) are formed at the color filter substrate 16. A
display area black matrix 20 and a peripheral area black matrix 22
are formed at the color filter substrate 16. The display area black
matrix 20 partitions the pixel regions 26 within the display area
to prevent leakage of light at the inter-pixel bordering area while
absorbing light directed at the thin film transistors to prevent
current leakage, The peripheral area black matrix 22 is provided to
absorb light directed at the peripheral area external to the
display area.
[0031] The array substrate 12 and the color filter substrate 16 are
assembled to face each other by way of an ultraviolet (UV)
hardening sealer 18 forming a gap there between. A liquid crystal
28 fills the gap between the substrates 12 and 16. The liquid
crystal is contained by the ultraviolet hardening sealer 18. The
sealer 18 is formed with a material that does not mix with the
liquid crystal 28 to prevent the liquid crystal 28 from being
contaminated if it comes in contact with the sealer 18 before the
sealer is hardened.
[0032] The substrates 12 and 16 are spaced apart from each other
with a predetermined cell gap. The distance of the cell gap is kept
constant by using spacers of a predetermined size (not shown).
However, if the distribution density of the liquid crystal 28 is
not uniform at the entire area of the substrates, the cell gap
cannot be maintained in a constant manner. In this case, the image
displayed on the display screen of the display device is
deteriorated. Therefore, the distribution density of the liquid
crystal 28 should be controlled in a uniform manner.
[0033] When the mother panel 10 is severed by cutting into the
liquid crystal display cell regions 10a, 10b, 10c and 10d along the
cutting lines A and B, the stress applied to the substrates 12 and
16 with the cutting should be minimized to prevent deformation of
the liquid crystal display cells and deterioration of the liquid
crystal 28.
[0034] A method of fabricating the liquid crystal display using an
in-line system will be now explained with reference to FIGS. 3 and
4.
[0035] FIG. 3 is a block diagram of the in-line system, and FIG. 4
illustrates a process of cutting the substrates using a substrate
cutting unit.
[0036] As shown in FIG. 3, the in-line system includes a first load
unit 100 where one-sided substrates are classified and loaded, a
spacer dispersing unit 200, a sealer coating unit 300, a liquid
crystal injection unit 400, and a first preliminary alignment unit
500. The in-line system further includes a second load unit 600, a
second preliminary alignment unit 700, an assembly unit 800, a
sealer hardening unit 900, a heat treatment unit 1000, a substrate
cutting unit 1100, and a substrate unload unit 1200. The first load
unit 100, the spacer dispersing unit 200, the sealer coating unit
300, the liquid crystal injection unit 400, the first preliminary
alignment unit 500, the assembly unit 800, the sealer hardening
unit 900: the heat treatment unit 1000, the substrate cutting unit
1100 and the unload unit 1200 are sequentially connected to each
other by way of an in-line transporter (not shown) capable of
transporting the substrates per the in-line processing time unit,
The second load unit 600 and the second preliminary alignment unit
700 are connected to the assembly unit 800 by way of another
in-line transporter (not shown). In case the time period of cutting
the substrates 12 and 16 at the substrate cutting unit 1100 differs
from the in-line processing time period, a plurality of substrate
cutting units may be provided to ensure that the processing is
in-line.
[0037] The bottom substrates 12 are classified, and loaded in the
first load unit 100. The spacer dispersing unit 200 disperses
spacers onto the bottom substrate 12 to maintain the gap between
the two substrates 12 and 16 in a constant manner. The sealer
coating unit 300 coats a sealer 18 onto the bottom substrate 12 in
the shape of a closed curve. The liquid crystal injection unit 400
drops liquid crystal 28 into the liquid crystal display cell
regions 10a to 10d defined by the sealer 18 of the bottom substrate
12 using a liquid crystal injector (not shown). The liquid crystal
injector may bear a shape of a syringe capable of dropping the
liquid crystal 28 in a small scale, or a shape of a sprayer with a
nozzle capable of dropping the liquid crystal 28 in a full scale,
The first preliminary alignment unit 500 preliminarily aligns the
bottom substrate 12 having the sealer 18 and the liquid crystal 28
with the top substrate 16 before the assembling.
[0038] The top substrates 16 are classified, and loaded in the
second load unit 600. The second preliminary alignment unit 700
preliminarily aligns the top substrate 16 with the bottom substrate
12 before the assembling. The assembly unit 800 assembles the
bottom and the top substrates 12 and 16 opposite each other.
Compression plates (not shown) are provided at the assembly unit
800 to apply pressure to the substrates 12 and 16. The sealer
hardening unit 900 hardens the sealer 18 interposed between the
substrates 12 and 16. The heat treatment unit 1000 makes heat
treatment with respect to the substrates 12 and 16 to align the
liquid crystal 28 in a stable manner. The substrate cutting unit
1100 illuminates a laser beam onto the substrates 12 and 16 along
the cutting lines A and B using a cutter to thereby sever the
substrates 12 and 16 into the liquid crystal display unit cell
regions 10a to 10d, The unload unit 1200 unloads the severed
substrates 12 and 16.
[0039] In case it is intended to form the spacers at the top
substrate 16, the spacer dispersing unit 200 may be positioned
between the second load unit 600 and the second preliminary
alignment unit 700,
[0040] The process of cutting the substrates using the substrate
cutting unit 1100 will now be explained with reference to FIG.
4.
[0041] As shown in FIG. 4, the substrate cutting unit 1100 includes
a laser 1101 for pre-heating the substrates 12 and 16 through
illuminating a laser beam along the cutting lines A and B. A
cooling agent sprayer 1103 is installed at the rear of the laser
1101 to spray a cooling agent to the laser-illuminated area such
that a minute crack is made at the substrates 12 and 16 along the
cutting lines A and B. The substrate cutting unit 1100 further
includes a laser transporter 1102 for fixing or transporting the
laser 1101 and the cooling agent sprayer 1103. The substrate
cutting unit 1100 may further include a substrate transporter for
fixing, transporting or rotating the mother panel 10 with the
bottom and top substrates 12 and 16 assembled by way of the sealer
18.
[0042] In the process of cutting the substrates 12 and 16, the
laser 1101 illuminates a laser beam onto the substrates 12 and 16
along the cutting lines A and B, thereby pre-heating the substrates
12 and 16 up to a predetermined temperature. Thereafter, the
cooling agent sprayer 1103 sprays a cooling agent onto the
pre-heated substrates 12 and 16 to thereby cool the pre-heated
substrates 12 and 16 in a rapid manner. Thermal compression and
thermal expansion are made at the substrates 12 and 16 along the
cutting lines A and B due to the heating and the cooling so that
high thermal stress is applied to the substrates 12 and 16.
Consequently, a minute crack is formed at the substrates 12 and 16
along the cutting lines A and B, and propagated along the cutting
lines A and B as the laser beam illumination and the cooling agent
spraying are made. In this way the mother panel 10 is completely
severed into the liquid crystal display unit cell regions 10a to
10d.
[0043] As described above, in the substrate cutting process, a
laser beam is illuminated onto the substrates 12 and 16 in a
non-contact manner to form a minute crack at the substrates 12 and
16. The minute crack is propagated, thereby severing the substrates
12 and 16. In this process, the laser-based cutter does not contact
the substrates 12 and 16 and stress from cutting substrates can be
prevented. Furthermore, as the formation and propagation of the
minute crack at the substrates 12 and 16 are made without applying
pressure to the substrates, deformation of the liquid crystal
display cell or deterioration of the liquid crystal and the
alignment films does not occur. Accordingly, the resulting display
device can involve the desired display characteristic in a stable
manner. In addition, as the liquid crystal display cell regions 10a
to 10d are designed without considering the cutting margin as with
the scribing process, the cell regions 10a to 10d can be enlarged
in size.
[0044] In sum, a laser is introduced in the substrate cutting
process while preventing the possible application of cutting stress
to the substrates so that the liquid crystal or the alignment films
are prevented from being deteriorated. Consequently, the display
characteristic of the resulting liquid crystal display can be
enhanced.
[0045] While the present invention has been described in detail
with reference to the preferred embodiments, those skilled in the
art will appreciate that various modifications and substitutions
can be made thereto without departing from the spirit and scope of
the present invention as set forth in the appended claims.
* * * * *