Liquid crystal cells – elements and systems – Particular structure – Having significant detail of cell structure only
Reexamination Certificate
2002-12-24
2004-09-21
Kim, Robert H. (Department: 2871)
Liquid crystal cells, elements and systems
Particular structure
Having significant detail of cell structure only
C349S187000, C438S033000
Reexamination Certificate
active
06795154
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a cutting apparatus, and more particularly, to an apparatus for cutting liquid crystal display panels and a cutting method using the same. Although the present invention is suitable for a wide scope of applications, it is particularly suitable for substantially reducing a process time in fabricating a liquid crystal display panel.
2. Discussion of the Related Art
A liquid crystal display device provides liquid crystal cells arranged in a matrix form with corresponding data signals according to image information in order to display a desired image by controlling light-transmittance of each liquid crystal cell. In order to improve yield, a method of fabricating the liquid crystal display device includes the steps of forming thin film transistor array substrates on a large mother substrate, forming color filter substrates on another mother substrate, bonding the two mother substrates to each other to form a plurality of liquid crystal display panels at the same time. Hence, the method demands a process of cutting the bonded mother substrates into unit liquid crystal display panels.
Such a cutting process of the unit panels generally includes forming a scribing line on a mother substrate by using a diamond pen having hardness greater than that of glass, and cutting the substrate by applying a mechanical force thereto. Such a cutting process of the unit panels will now be explained in detail by referring to the attached drawings as follows.
FIG. 1
illustrates a schematic layout of a related art unit liquid crystal display panel prepared by bonding a thin film transistor array substrate and a color filter substrate to each other.
Referring to
FIG. 1
, a liquid crystal display panel
10
includes an image display part
13
having liquid crystal cells arranged in a matrix form, a gate pad part
14
connected to gate lines of the image display part
13
, and a data pad part
15
connected to data lines. In this case, the gate and data pad parts
14
and
15
are respectively formed on the edge areas of a thin film transistor array substrate
1
which does not overlap a color filter substrate
2
. The gate pad part
14
provides the gate lines of the image display part
13
with each corresponding scan signal supplied from a gate driver integrated circuit, and the data pad part
15
provides the data lines with image information supplied from a data driver integrated circuit.
On the thin film transistor array substrate
1
of the image display unit
13
, the data lines having the image information applied thereto and the gate lines having the scan signals applied thereto are arranged to vertically cross each other. Thin film transistors at each intersection are formed to switch the liquid crystal cells. Pixel electrodes are connected to the thin film transistors to drive the liquid crystal cells. A passivation layer is formed on the entire surface to protect the electrodes and the thin film transistors.
Moreover, color filters separated by a black matrix for each cell area are formed on the color filter substrate
2
. A transparent common electrode as a counter electrode of the pixel electrode is formed on the thin film transistor array substrate
1
.
A cell gap is provided between the thin film array substrate
1
and the color filter substrate
2
, which are bonded to each other by a sealing part (not shown) formed at the periphery of the image display unit
13
, so as to be spaced apart from each other. A liquid crystal layer (not shown) is formed in the space between the thin film transistor array substrate
1
and the color filter substrate
2
.
FIG. 2
illustrates a cross-sectional view of a first mother substrate having thin film transistor array substrates
1
and a second mother substrate having color filter substrates
2
, wherein the first and second mother substrates are bonded to each other to form a plurality of liquid crystal display panels.
Referring to
FIG. 2
, each unit liquid crystal display panel has a thin film transistor array substrate longer than a corresponding color filter substrate
2
. This is because the gate and data pad parts
14
and
15
are formed at the corresponding edges of the thin film transistor array substrate
1
which does not overlap the color filter substrate
2
, as shown in FIG.
1
.
Hence, the second mother substrate
30
and the color filter substrates
2
formed thereon are spaced apart from each other by a dummy area
31
corresponding to the protruding area of each thin film transistor array substrate
1
on the first mother substrate
20
.
Moreover, the unit liquid crystal display panels are arranged so as to maximize the use of the first and second mother substrates
20
and
30
. Although it depends on models, the unit liquid crystal display panel is generally spaced apart from each other at a distance corresponding to the area of the other dummy area
32
.
After the first mother substrate
20
having the thin film transistor array substrates
1
is bonded to the second mother substrate
30
having the color filter substrates
2
, a scribing process and a breaking process are carried out to individually cut the liquid crystal display panels. In this case, the dummy area
31
formed between each color filter substrate
2
of the second mother substrate
30
and the other dummy area
32
formed between each unit liquid crystal display panel are removed at the same time.
The related art cutting process of the unit liquid crystal display panels is explained in detail by referring to
FIGS. 3A
to
3
J as follows.
Referring to
FIG. 3A
, first and second mother substrates
20
and
30
bonded to each other are loaded on a first table
33
.
In
FIG. 3B
, the first table
33
moves in one direction to a previously set distance to sequentially form a first scribing line
42
on the first mother substrate
20
through a cutting wheel
41
.
Referring to
FIG. 3C
, the first and second mother substrates
20
and
30
are turned by 90°. The first table
33
moves back to its initial location at the previously set distance to sequentially form a second scribing line
43
on a surface of the first mother substrate
20
through the cutting wheel
41
.
As shown in
FIG. 3D
, the first and second mother substrates
20
and
30
are overturned and are loaded on a second table
34
. The second table
34
moves in one direction at a previously set distance, and propagates a crack on the first mother substrate
20
by pressing the second mother substrate
30
with a breaking rod
44
along the second scribing line
43
.
As shown in
FIG. 3E
, after the second and first mother substrates
30
and
20
are turned by 90°, the second table
34
moves back to its initial location at the previously set distance, and propagates a crack on the first mother substrate
20
by pressing the second mother substrate
30
along the first scribing line
42
with the breaking rod
44
.
As shown in
FIG. 3F
, after the second and first mother substrates
30
and
20
are loaded on a third table
35
, the third table
35
moves in one direction at a previously set distance to sequentially form a third scribing line
46
on the surface of the second mother substrate
30
through a cutting wheel
45
.
Referring to
FIG. 3G
, the second and first mother substrates
30
and
20
are turned by 90°, and the third table
35
moves back to its initial location at the previously set distance to form a fourth scribing line
47
on the surface of the second mother substrate
30
through the cutting wheel
45
.
As shown in
FIG. 3H
, the second and first mother substrates
30
and
20
are overturned to be loaded on a fourth table
36
. The fourth table
36
moves in one direction at a previously set distance and propagates a crack on the second mother substrate
30
by pressing the first mother substrate
20
with a breaking rod
48
along the fourth scribing line
47
.
In
FIG. 3I
, after the first and second mother substrates
20
and
30
are turned by 90°, the fourth table
36
moves back
Shin Sang-Sun
Uh Ji-Heum
Kim Robert H.
LG. Philips LCD Co. Ltd.
Morgan & Lewis & Bockius, LLP
Qi Mike
LandOfFree
Apparatus for cutting liquid crystal display panels and... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Apparatus for cutting liquid crystal display panels and..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Apparatus for cutting liquid crystal display panels and... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3245947