U.S. patent application number 10/709431 was filed with the patent office on 2005-07-14 for [liquid crystal display panel and method of fabrication thereof].
Invention is credited to Chou, Yi-Lun, Jen, Tean-Sen, Lee, Seok-Lyul, Lin, Ming-Tien.
Application Number | 20050151899 10/709431 |
Document ID | / |
Family ID | 34738204 |
Filed Date | 2005-07-14 |
United States Patent
Application |
20050151899 |
Kind Code |
A1 |
Chou, Yi-Lun ; et
al. |
July 14, 2005 |
[LIQUID CRYSTAL DISPLAY PANEL AND METHOD OF FABRICATION
THEREOF]
Abstract
A liquid crystal display panel comprises a first substrate, a
second substrate, a sealant, a liquid crystal layer, and a
light-shielding layer, wherein the sealant is disposed between the
first substrate and the second substrate; the liquid crystal layer
is disposed among the first substrate, the second substrate and the
sealant; and the light shielding layer is disposed on a surface of
the first substrate but notin contact with the liquid crystal
layer.
Inventors: |
Chou, Yi-Lun; (Taipei City,
TW) ; Lee, Seok-Lyul; (Taoyuan County, TW) ;
Jen, Tean-Sen; (Taoyuan Hsien, TW) ; Lin,
Ming-Tien; (Taipei County, TW) |
Correspondence
Address: |
JIANQ CHYUN INTELLECTUAL PROPERTY OFFICE
7 FLOOR-1, NO. 100
ROOSEVELT ROAD, SECTION 2
TAIPEI
100
TW
|
Family ID: |
34738204 |
Appl. No.: |
10/709431 |
Filed: |
May 5, 2004 |
Current U.S.
Class: |
349/110 |
Current CPC
Class: |
G02F 1/133512 20130101;
G02F 1/13415 20210101; G02F 1/1333 20130101 |
Class at
Publication: |
349/110 |
International
Class: |
G02F 001/1333 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 14, 2004 |
TW |
93100862 |
Claims
1. A liquid crystal display panel, comprising: a first substrate,
having a first surface and a second surface; a second substrate,
having a third surface; a sealant, disposed between the second
surface and the third surface; a liquid crystal layer, disposed
among the second surface, the third surface and the sealant; and a
light-shielding layer, disposed over the first surface and not
overlapping a display area.
2. The liquid crystal display panel of claim 1, wherein a material
of the light-shielding layer is an ink.
3. The liquid crystal display panel of claim 2, wherein the ink is
a black ink.
4. The liquid crystal display panel of claim 1, wherein an optical
density of the light-shielding layer is 2.0 or more than 2.0.
5. The liquid crystal display panel of claim 1, wherein the
light-shielding layer surrounds the display area and is in a shape
of a frame.
6. The liquid crystal display panel of claim 1, further comprises a
black matrix layer disposed between the first substrate and the
second substrate.
7. The liquid crystal display panel of claim 6, wherein a width of
the light-shielding layerpartially projectively overlaps the black
matrix layer.
8. The liquid crystal display panel of claim 7, wherein the width
of the light-shielding layer exposes a portion of the sealant.
9. A method of fabricating a liquid crystal display panel,
comprising: providing a first substrate having a first inner
surface and a first outer surface; providing a second substrate
having a second inner surface and a second outer surface; forming a
sealant between the first inner surface of the first substrate and
the second inner surface of the second substrate; forming a liquid
crystal layer in a space between the sealant, the first inner
surface and the second inner surface; and forming a light-shielding
layer over the first outer surface of either the first substrate or
the second outer surface of the second substrate.
10. The method of fabricating a liquid crystal display panel of
claim 9, wherein a material of the light-shielding layer is an
ink.
11. The method of fabricating a liquid crystal display panel of
claim 9, wherein the light-shielding layer is formed via an ink jet
printing method, a screen printing method or a gravure printing
method.
12. The method of fabricating a liquid crystal display panel of
claim 10, wherein the ink is a black ink.
13. The method of fabricating a liquid crystal display panel of
claim 9, wherein an optical density of the light-shielding layer is
2.0 or more than 2.0.
14. The method of fabricating a liquid crystal display panel of
claim 9, wherein the liquid crystal display panel comprises a
display area, and the light-shielding layer is disposed on a
peripheral area outside the display area.
15. The method of fabricating a liquid crystal display panel of
claim 14, wherein the light-shielding layer surrounds the display
area and is in a shape of a frame.
16. The method of fabricating a liquid crystal display panel of
claim 9, wherein the first substrate is a thin film transistor
array substrate or a color filter substrate; when the first
substrate is the thin film transistor array substrate, the second
substrate is the color filter substrate; and when the first
substrate is the color filter substrate, the second substrate is
the thin film transistor array substrate.
17. The method of fabricating a liquid crystal display panel of
claim 9, further comprising a step of forming a black matrix layer
over a surface of the first substrate or the second substrate.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the priority benefit of Taiwan
application serial no. 93100862, filed Jan. 14, 2004.
BACKGROUND OF INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a liquid crystal display
panel and a method of fabrication thereof, and more particularly to
a liquid crystal display and a method of fabrication thereof for
reducing light leakage at edges of bezel of a liquid crystal
display module.
[0004] 2. Description of Related Art
[0005] Liquid Crystal Display (LCD) has advantages, such as small
size, low weight, low driving voltage, low power consumption, and
portability. It was applied in the display of the portable terminal
system during the past twenty years and widely used.
[0006] A One Drop Fill (ODF) process is adapted for fabricating a
large-panel LCD display in which amount of the liquid crystal
material can be properly controlled for reducing the fabrication
costs. Further, the ODF process is capable of substantially
reducing the process time to fill liquid crystal. Therefore, the
ODF process can be meaningfully applied for mass-production LCD
display.
[0007] In a typical ODF process, a radiation-curable adhesive is
coated over a thin film transistor array substrate or over a color
filter film substrate to form a sealed area. Then the liquid
crystal is dropped into the sealed area. The thin film transistor
array substrate is attached to the color filter film substrate.
Finally, the resulting structure is exposed to, for example, a UV
light, for hardening the radiation-curable adhesive and thereby
bonding the substrates.
[0008] FIG. 1 is a cross-sectional view showing a prior art liquid
crystal display module formed by using the ODF process. For
simplification, FIG. 1 shows only the essential elements of an LCD
display. Referring to FIG. 1, the liquid crystal display module
comprises: a thin film transistor array substrate 102, a color
filter film substrate 104, a black matrix layer 106, a sealant 108,
a liquid crystal layer 110, polarizers 112 and 114, and a bezel
116. The black matrix layer 106 is disposed over the color filter
film substrate 104. The sealant 108 is disposed between the thin
film transistor array substrate 102 and the color filter film
substrate 104. The liquid crystal layer 110 is disposed in the
sealed space formed by the thin film transistor array substrate
102, the color filter film substrate 104 and the sealant 108. The
polarizers 112 and 114 are separately disposed over the surfaces of
the thin film transistor array substrate 102 and the color filter
film substrate 104 such that the polarizers 112 and 114 do not
contact the liquid crystal layer 110. The bezel is disposed over
the polarizer 112.
[0009] The sealant 108 is hardened by exposing the sealant 108 to
the UV light during the ODF process, and therefore it is important
that the black matrix layer 106 does not block the sealant 108.
Moreover, the ODF process requires that the black matrix layer 106
over the color filter film substrate 104 should be separated from
the sealant 108 with a distance as shown in FIG. 1.
[0010] Today, the process of fabricating the liquid crystal display
panel/module should fit the Standard Panel Work Group (SPWG)
specification. Despite the LCD display is being fabricated using
the ODF process fitting the SPWG specification, light leakage 120
will invariably occur at the edges of the bezel 116 at about the
view angle 45.degree. as shown in the magnified view of part A.
[0011] Some prior art proposed to extend the black matrix layer 106
to outside. But to fit the SPWG specification, the dimension of the
liquid crystal cell should be increased. Accordingly, the notebook
computers cannot satisfy the SPWG specification.
SUMMARY OF INVENTION
[0012] The present invention is directed to a liquid crystal
display panel and a fabrication method thereof, for reducing the
light leakage of the liquid crystal display module.
[0013] The present invention is directed to a liquid crystal
display panel and a method of fabrication thereof using the ODF
process fitting the SPWG specification. Further, the light leakage
of the liquid crystal display module fabricated using the ODF
process can be reduced.
[0014] According to an embodiment of the present invention, the
liquid crystal display panel comprises a first substrate; a second
substrate; a sealant, disposed between the first substrate and the
second substrate; a liquid crystal layer, disposed among the first
substrate, the second substrate and the sealant; and a
light-shielding layer, disposed over a surface of the first
substrate such that the light-shielding layer does not contact the
liquid crystal layer.
[0015] According to an embodiment of the present invention, the
method of fabricating the liquid crystal display panel comprises,
first, a first substrate and a second substrate are provided. Next,
a sealant is formed over a surface of the first substrate. Next, a
liquid crystal layer is filled into the sealant formed over the
surface of the first substrate. Next, the first substrate is
attached onto the second substrate. Next, the sealant is exposed to
a light. Thereafter, a light-shielding layer is formed over a
surface of the first substrate such that the light-shielding layer
does not contact the liquid crystal layer.
[0016] According to an embodiment of the present invention, the
material of the light-shielding layer comprises, for example but
not limited to, an ink or a black ink.
[0017] According to an embodiment of the present invention, the
optical density of the light-shielding layer is, for example but
not limited to, 2.0 or more than 2.0.
[0018] According to an embodiment of the present invention, the
liquid crystal display panel comprises a display area, and the
light-shielding layer is disposed over a peripheral area outside
the display area of the first substrate.
[0019] According to an embodiment of the present invention, the
light-shielding layer is formed over the substrate of the liquid
crystal display panel. When the liquid crystal display panel is
applied in an electronic product, the light-shielding layer is
capable of reducing the light leakage at the bezel edge of the
liquid crystal display module.
[0020] According to an embodiment of the present invention, the
light-shielding layer is formed over the substrate after the
sealant is hardened. The liquid crystal display panel can be
fabricated by using the ODF process fitting the SPGW specification.
Further, the light leakage of the liquid crystal display module
fabricated by the ODF process can be reduced.
[0021] In order to make the aforementioned and other objects,
features and advantages of the present invention understandable, a
preferred embodiment accompanied with figures is described in
detail below.
BRIEF DESCRIPTION OF DRAWINGS
[0022] FIG. 1 is a cross-sectional view showing a prior art liquid
crystal display module fabricated by using an ODF process.
[0023] FIGS. 2A-2D are cross-sectional views showing progressive
process steps of a ODF process of fabricating a liquid crystal
display panel according to an embodiment of the present
invention.
[0024] FIG. 3 is a top view of the liquid crystal display panel
shown in FIG. 2D.
[0025] FIG. 4 is a cross-sectional view showing a liquid crystal
display module fabricated using an ODF process according to an
embodiment of the present invention.
[0026] FIG. 5 is a cross-sectional view showing a liquid crystal
display panel fabricated using an ODF process according to an
embodiment of the present invention.
[0027] FIG. 6 is a cross-sectional view showing a liquid crystal
display module fabricated using an ODF process according to an
embodiment of the present invention.
DETAILED DESCRIPTION
[0028] FIGS. 2A-2D are cross-sectional views showing progressive
process steps of an ODF process of fabricating a liquid crystal
display panel according to an embodiment of the present invention.
For simplification, the figures show only the essential
elements.
[0029] Referring to FIG. 2A, a first substrate 202, for example but
not limited to, a plastic substrate or a glass substrate, is
provided. Next, a thin film transistor array (not shown) is formed
over the substrate 202 to form a thin film transistor array
substrate. For example, each transistor comprises a channel region
comprised of .alpha.-Si, Poly-Si, orthe like.
[0030] A second substrate 204, for example but not limited to, a
plastic substrate or a glass substrate, is provided. A color filter
film (not shown) is formed, for example, directly on the substrate
204, or the color filter film is formed first and then applied on
the substrate,to form a color filter film substrate. A black matrix
layer 206 is formed over the second substrate 204. The sealant 208
is coated over the substrate 202 to form a sealed area, wherein the
sealant 208 can be, for example but not limited to, a
radiation-curable adhesive.
[0031] Referring to FIG. 2B, liquid crystal is dropped into the
sealed area to form a liquid crystal layer 210. Referring to FIG.
2C, the first substrate 202 is attached to the second substrate
204. UV light is applied through the edges of the substrate 204 to
harden the sealant 208, and thereby attach the first substrate 202
onto the second substrate 204.
[0032] Referring to FIGS. 2D and 3, wherein FIG. 3 is a top view of
the liquid crystal display panel shown in FIG. 2D. A
light-shielding layer 214 is formed over a surface of the substrate
204 such that the light-shielding layer 214 does not contact the
liquid crystal layer 210. As shown in FIG. 3, the light-shielding
layer 214 is disposed over a peripheral area outside the displayer
area 230 of the liquid crystal display panel. In an embodiment of
the present invention, the light-shielding layer 214, for example,
surrounds the display area 230 and has a frame shape. Thereafter, a
liquid crystal display panel comprising the light-shielding layer
214 is fabricated according to the process steps described with
reference to FIGS. 2A-2D.
[0033] According to an embodiment of the present invention, the
light-shielding layer 214 is formed by using materials, for
example, having an optical density of about 2.0 or higher than 2.0.
The material of the light-shielding layer 214 comprises, for
example but not limited to, ink, which can be formed, for example,
by using an ink jet printing method, a screen printing method or a
gravure printing method. Moreover, according to an embodiment of
the present invention, the light-shielding layer 214 is capable of
shielding the light, and the ink is, for example but not limited
to, a black ink.
[0034] FIG. 4 is a cross-sectional view showing a liquid crystal
display module fabricated using an ODF process according to an
embodiment of the present invention. For simplification, FIG. 4
shows only the essential elements. Referring to FIG. 4, the liquid
crystal display module comprises the liquid crystal display panel
of FIG. 2D, polarizers 216 and 218, and a bezel 220. The liquid
crystal display panel comprises the first and second substrates 202
and 204, the black matrix layer 206, the sealant 208, the liquid
crystal layer 210 and the light-shielding layer 214.
[0035] According to an embodiment of the present invention, the
black matrix layer 206 is disposed over the substrate 204, the
sealant 208 is disposed between the first and second substrates 202
and 204, and the liquid crystal layer 210 is disposed in the sealed
space among the first and second substrates 202 and 204 and the
sealant 208. The light-shielding layer 214 is disposed over another
surface of the substrate 204 such that the light-shielding layer
214 does not contact the liquid crystal layer 210. The
light-shielding layer 214 is disposed over the peripheral area
outside the display area (not shown) of the liquid crystal display
panel. The optical density of the light-shielding layer 214 is, for
example but not limited to, 2.0 or more than 2.0. The material of
the light-shielding layer 214 can be, for example but not limited
to, ink and the ink can be, for example but not limited to, a black
ink.
[0036] According to an embodiment of the present invention, the
light-shielding layer 214 projectingly overlaps the edge of black
matrix layer to reduce the light leakage. The width of the
light-shielding layer 214 may extend toward an edge of the first
and second substrates exposing at least a portion of the sealant
depending on the hardening process.
[0037] Referring to FIG. 4, the polarizers 216 and 218 are
separately disposed on the surfaces of the first and second
substrates 202 and 204 such that the polizers 216 and 218 do not
contact the liquid crystal layer 210. The polarizer 216 is disposed
over the second substrate 204 covering the light-shielding layer
214. The bezel 220 is disposed over the polarizer 216 covering a
part of peripheral area of the liquid crystal display panel.
[0038] When the exemplary liquid crystal display panel comprising
the light-shielding layer of FIG. 2D is applied to the liquid
crystal display module, because the light-shielding layer 214 is
disposed over the substrate 204, the light leakage 240 can be
shielded by the light-shielding layer 214 as shown in the magnified
view of the part B. Therefore, the light leakage at the edges of
the bezel 220 of the liquid crystal display module can be
effectively reduced.
[0039] In the embodiment described above, the light-shielding layer
214 is disposed over the substrate 204 (the color filter film
substrate). However, the present invention present is limited to
the embodiment described above. FIG. 5 is a cross-sectional view
showing a liquid crystal display panel formed using an ODF process
according to another embodiment of the present invention. The
elements of the liquid crystal display panel in FIG. 5 are similar
to the liquid crystal display panel in FIG. 2 with the same
reference numbers and the detail descriptions thereof will not be
repeated hereinafter.
[0040] Further, the structure of the liquid crystal display panel
in FIG. 5 is similar to that in FIG. 2D except for the
light-shielding layer 250 is disposed over another surface of the
first substrate 202 (the thin film transistor array substrate) and
not in contact with the liquid crystal layer 210. The liquid
crystal display panel can be fabricated using the process steps
with reference to FIGS. 2A-2C described above. Further, the
light-shielding layer 250 can be, for example, fabricated using a
process similar to that used for fabricating the light-shielding
layer 214. The light-shielding layer 250 can be, for example,
disposed over the peripheral area outside the display area 230 of
the liquid crystal display panel. In this embodiment, the
light-shielding layer 250, for example, surrounds the display area
230 and in a shape of a frame.
[0041] FIG. 6 is a cross-sectional view showing a liquid crystal
display module fabricated using an ODF process according to another
embodiment of the present invention. In this embodiment, the liquid
crystal display panel shown in FIG. 5 is utilized to fabricate the
liquid crystal display module. It should be noted that elements of
the liquid crystal display panel in FIG. 6 are similar to those in
FIG. 4 and have the same reference numbers and the detail
descriptions are not repeated hereinafter. The structure of the
liquid crystal display panel shown in FIG. 5 is similar to that
shown in FIG. 4 except for the light-shielding layer 250 is
disposed over another surface of the substrate 202 not in contact
with the liquid crystal layer 210. Further, because the material
and location of the light-shielding layer 250 are similar to those
described in FIG. 5, detail descriptions thereof are not repeated
hereinafter.
[0042] When the liquid crystal display panel comprising the
light-shielding layer of the present embodiment (FIG. 5) is applied
to the liquid crystal display module, because the light-shielding
layer 250 is disposed on the substrate 202, the light 260 emitted
from backlight module (not shown) can be shielded by the
light-shielding layer 250 as shown in FIG. 6. In other words, the
surface of the substrate 202 can shield the light leakage outside
the display area 230. Therefore, the light leakage at the edges of
the bezel 220 of the liquid crystal display module can be
effectively reduced.
[0043] In an embodiment of the present invention, the thin film
transistor array substrate comprises, for example but not limited
to, bottom gate thin film transistors. However, the present
invention is not limited thereto. According to an embodiment of the
present invention, a low-temperature polysilicon thin film
transistor process or any other active matrix liquid crystal
display process may be applied for fabricating the liquid crystal
display panel.
[0044] According to an embodiment of the present invention, the ink
of the light-shielding layer is a black ink. However, the present
invention is not limited thereto. Alternatively, the color of the
ink can be of any color as long as the color of the ink can
effectively shield light.
[0045] According to an embodiment of the present invention, the
sealant is disposed over the first substrate 202 (the thin film
transistor array substrate). The liquid crystal layer is formed
over the substrate 202 within the sealed space surrounded by the
sealant. However, the present invention is not limited thereto. The
sealant 208 can be formed over the second substrate 204 (the color
filter substrate). The liquid crystal layer is formed over the
second substrate 204 within the sealed space surrounded by the
sealant.
[0046] According to an embodiment of the present invention, the
black matrix layer is disposed over the substrate 204 (the color
filtersubstrate). After the first substrate 202 is placed onto the
second substrate 204, the edges of the substrate 204 are exposed to
light to cure the sealant comprising the radiation-curable
adhesive. However, the present invention is not limited thereto.
The black matrix layer can also be disposed over the substrate 202
(the thin film transistor array substrate). Moreover, as long as
the light-shielding layer shields leakage light, the black matrix
can be disposed over the same substrate or over different
substrates.
[0047] Furthermore, the light-shielding layer comprises ink,
however the present invention is not limited thereto. As long as
the light-shielding layer is disposed over another surface of the
substrate not in contact with the liquid crystal layer fabricated
using the ODF process, it is considered to be within the scope of
the present invention.
[0048] Accordingly, the present invention has following advantages:
1. The liquid crystal display panel of the present invention has
the light-shielding layer formed over the substrate. When the
liquid crystal display panel is applied to the electronic product,
the light-shielding layer is capable of shielding the leakage light
at the edges of the bezel of the liquid crystal display module and
thereby reducing the light leakage from the liquid crystal display
module. 2. As to the method of fabricating the liquid crystal
display panel using the ODF process, the light-shielding layer is
formed on the substrate after the liquid crystal display panel is
exposed to a light for hardening the sealant. The liquid crystal
display panel can be fabricated using the ODF process fitting the
SPGW specification, and also reduce the light leakage issue of the
liquid crystal display module.
[0049] Although the present invention has been described in terms
of exemplary embodiments, it is not limited thereto. Rather, the
appended claims should be constructed broadly to include other
variants and embodiments of the invention which may be made by
those skilled in the field of this art without departing from the
scope and range of equivalents of the invention.
* * * * *