U.S. patent application number 11/682262 was filed with the patent office on 2008-04-17 for liquid crystal display panel.
Invention is credited to Mu-Jen Su.
Application Number | 20080088757 11/682262 |
Document ID | / |
Family ID | 39302744 |
Filed Date | 2008-04-17 |
United States Patent
Application |
20080088757 |
Kind Code |
A1 |
Su; Mu-Jen |
April 17, 2008 |
LIQUID CRYSTAL DISPLAY PANEL
Abstract
A liquid crystal display panel includes a first substrate, a
second substrate, a pixel disposed on the second substrate, a
bottom capacitor electrode, a top capacitor electrode, a liquid
crystal layer disposed between the first substrate and the second
substrate, and a plurality of protrusions disposed on the first
substrate. The pixel includes a first pixel electrode and a second
pixel electrode, in which a main slit is formed between the first
pixel electrode and the second pixel electrode. The bottom
capacitor electrode is disposed on the second substrate and
overlaps a portion of the main slit, and the top capacitor
electrode is disposed on the second substrate and forms a capacitor
with the bottom capacitor electrode.
Inventors: |
Su; Mu-Jen; (Hsin-Chu,
TW) |
Correspondence
Address: |
NORTH AMERICA INTELLECTUAL PROPERTY CORPORATION
P.O. BOX 506
MERRIFIELD
VA
22116
US
|
Family ID: |
39302744 |
Appl. No.: |
11/682262 |
Filed: |
March 5, 2007 |
Current U.S.
Class: |
349/38 |
Current CPC
Class: |
G02F 1/134309 20130101;
G02F 1/136213 20130101; G02F 1/133707 20130101; G02F 1/1393
20130101 |
Class at
Publication: |
349/38 |
International
Class: |
G02F 1/1343 20060101
G02F001/1343 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 16, 2006 |
TW |
095138051 |
Claims
1. A liquid crystal display panel, comprising: a first substrate
and a second substrate disposed opposite to the first substrate; a
pixel, comprising a first pixel electrode, a second pixel electrode
and a bridge electrode formed between the first pixel electrode and
the second electrode, disposed on the second substrate, wherein a
main slit is formed among the first pixel electrode, the second
pixel electrode and the bridge electrode; a bottom capacitor
electrode disposed on the second substrate and overlaps a portion
of the main slit; a top capacitor electrode disposed on the second
substrate and forms a capacitor with the bottom capacitor
electrode; and a liquid crystal layer disposed between the first
substrate and the second substrate.
2. The liquid crystal display panel of claim 1, wherein the top
capacitor electrode partially overlaps the main slit.
3. The liquid crystal display panel of claim 1, wherein the bridge
electrode has a slant.
4. The liquid crystal display panel of claim 1, further comprising
a common electrode disposed on the first substrate.
5. The liquid crystal display panel of claim 4, further comprising
a plurality of color filters disposed between the first substrate
and the common electrode.
6. The liquid crystal display panel of claim 1, wherein each of the
first pixel electrode and the second pixel electrode comprises a
transmitting electrode or a reflective electrode.
7. The liquid crystal display panel of claim 1, wherein the first
pixel electrode and the second pixel electrode are comprised of
indium tin oxide or indium zinc oxide.
8. The liquid crystal display panel of claim 1, further comprising
a plurality of thin film transistors disposed on the second
substrate.
9. The liquid crystal display panel of claim 1, further comprising
a plurality of protrusions disposed on the first substrate.
10. The liquid crystal display panel of claim 9, wherein the bridge
electrode comprises a central portion and two end portion, wherein
the width of each of the end portion is greater than the width of
the central portion.
11. The liquid crystal display panel of claim 9, wherein the bridge
electrode is rectangular bridge electrode.
12. The liquid crystal display panel of claim 1, wherein the liquid
crystal layer comprises a plurality of negative liquid
crystals.
13. The liquid crystal display panel of claim 1, further comprising
a third pixel electrode connected to the second pixel electrode on
the second substrate.
14. The liquid crystal display panel of claim 13, wherein the third
pixel electrode comprises a transmitting electrode or a reflective
electrode.
15. The liquid crystal display panel of claim 1, wherein the bridge
electrode comprises a central portion and two end portion, wherein
the width of each of the end portion is greater than the width of
the central portion.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates to a liquid crystal display panel, and
more particularly, to a multi-domain vertical alignment liquid
crystal display panel.
[0003] 2. Description of the Prior Art
[0004] Liquid crystal displays are commonly utilized in various
electronic products including cell phones, PDAs, and notebook
computers. As the market demand for large-scale display panels
continues to increase, liquid crystal displays having advantages
such as small size and light weight have become widely popular. In
fact, liquid crystal displays are gradually replacing the
conventional cathode ray tube (CRT) displays that had dominated the
market for so many years. However, the viewing angle of the
conventional liquid crystal displays is not sufficiently wide to
ensure a high display quality, therefore, the development of liquid
crystal displays is limited by this important factor. A
multi-domain vertical alignment (MVA) or premium multi-domain
vertical alignment (PMVA) display capable of orientating liquid
crystals in various directions is therefore made to improve the
problem of insufficient viewing angle resulted from the
conventional displays.
[0005] Please refer to FIGS. 1-2. FIG. 1 is a plan view diagram
illustrating a pixel of a multi-domain vertical alignment liquid
crystal display 10 according to the prior art. FIG. 2 is a
cross-section diagram of FIG. 1 along the sectional line AA'. As
shown in FIG. 1 and FIG. 2, the conventional multi-domain vertical
alignment liquid crystal display panel 10 includes a top substrate
12, a bottom substrate 14, a liquid crystal layer 16 having
negative liquid crystals disposed between the top substrate 12 and
the bottom substrate 14, and a first pixel electrode 20 and a
second pixel electrode 28 disposed between the liquid crystal layer
16 and the bottom substrate 14.
[0006] A common electrode 18 disposed on the top substrate 12. A
plurality of color filters (not shown) is disposed between the top
substrate 12 and the common electrode 18. A plurality of
protrusions 22 disposed with respect to the first pixel electrode
20 and the second pixel electrode 28. On the other hand, a
capacitor 32 is disposed on the bottom substrate 14. The capacitor
32 is specifically disposed corresponding to the protrusions 22 of
the top substrate 12.
[0007] Each of the first pixel electrode 20 and the second pixel
electrode 28 can be a transmitting electrode composed of indium tin
oxide or indium zinc oxide or a reflective electrode. The first
pixel electrode 20 and the second pixel electrode 28 are separated
by a main slit 26 and connected to each other by a rectangular
bridge electrode 24, which can be a transmitting electrode.
[0008] The capacitor 32 is composed of a top capacitor electrode
38, a bottom capacitor electrode 34, and a dielectric layer 36
disposed between the top capacitor electrode 38 and the bottom
capacitor electrode 34. Typically, the capacitor electrodes 36 and
38 are connected according to a parallel manner for forming a
capacitor. The parallel connection of the capacitor increases the
capacity of the capacitor and maintains the voltage of the
capacitor.
[0009] Referring back to FIG. 1, the conventional capacitor is
typically formed corresponding to the position of the protrusions.
This design improves the problem of light leakage caused by
unstable alignment of liquid crystals during dark state and
increases the contrast of the display panel.
SUMMARY OF THE INVENTION
[0010] The present invention discloses a liquid crystal display
panel. The liquid crystal display panel includes a first substrate,
a second substrate, a pixel disposed on the second substrate, a
bottom capacitor electrode, a top capacitor electrode, a liquid
crystal layer disposed between the first substrate and the second
substrate, and a plurality of protrusions disposed on the first
substrate. The pixel includes a first pixel electrode and a second
pixel electrode, in which a main slit is formed between the first
pixel electrode and the second pixel electrode. The bottom
capacitor electrode is disposed on the second substrate and
overlaps a portion of the main slit, and the top capacitor
electrode is disposed on the second substrate and forms a capacitor
with the bottom capacitor electrode.
[0011] Specifically, the capacitor of the present invention is
formed corresponding to the position of the main slit between the
two pixel electrodes.
[0012] These and other objectives of the present invention will no
doubt become obvious to those of ordinary skill in the art after
reading the following detailed description of the preferred
embodiment that is illustrated in the various figures and
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a plan view diagram illustrating a pixel of a
multi-domain vertical alignment liquid crystal display according to
the prior art.
[0014] FIG. 2 is a cross-section diagram of FIG. 1 along the
sectional line AA'.
[0015] FIG. 3 is a plan view of a pixel of a multi-domain vertical
alignment liquid crystal display panel according to a preferred
embodiment of the present invention.
[0016] FIG. 4 is a cross-section diagram of FIG. 3 along the
sectional line BB'.
[0017] FIG. 5 is a cross-section diagram of FIG. 3 along the
sectional line CC'.
[0018] FIG. 6 illustrates a plan view of a pixel of a multi-domain
vertical alignment liquid crystal display panel according to an
embodiment of the present invention.
DETAILED DESCRIPTION
[0019] The stability of the liquid crystal and the uniformity of
the display region are typically determined by whether the liquid
crystals are positioned according to a .+-.90.degree. angle. In
most cases, a maximum stability can be achieved if the
.+-.90.degree. angle of the liquid crystals is in the center of the
pixel. Otherwise, the domain of the display region would result in
an uneven state. Since the angle of the liquid crystals is governed
by the magnitude of the electric field or the influence contributed
by the protrusions and the main slits, the conventional design of
having only one bridge electrode is often affected by the force
pulling from either left or right side, thus affecting the uniform
state of the liquid crystals. The result causes the .+-.90.degree.
angle of the liquid crystals to be present in regions other than
the center of the bridge electrode, which ultimately causes the
liquid crystals to shift toward left, right, or other unexpected
directions.
[0020] It is an objective of the present invention to provide a
multi-domain vertical alignment liquid crystal display panel for
improving the problem of light leakage of the main slit region
during dark state and preventing the liquid crystals from shifting
toward left or right as a result of using the single bridge
electrode design.
[0021] It is another aspect of the present invention to provide a
multi-domain vertical alignment liquid crystal display panel for
solving the problem of light leakage with respect to the main slit
region as the capacitor is formed corresponding to the position of
the protrusions.
[0022] The present invention specifically forms the capacitor in a
position corresponding to the main slit between two pixel
electrodes. Preferably, the capacitor can be used to reduce the
light leakage of the main slit region for increasing the usability
of high pixels and the overall aperture ratio of the display panel.
Additionally, a bridge electrode having a shrinking pattern can be
formed while the capacitor is disposed with respect to the main
slit, such that the shrinking pattern of the bridge electrode can
be used to improve uneven distribution of liquid crystals found in
conventional rectangular bridge electrodes.
[0023] Please refer to FIGS. 3-5. FIG. 3 is a plan view of a pixel
of a multi-domain vertical alignment liquid crystal display panel
40 according to a preferred embodiment of the present invention.
FIG. 4 is a cross-section diagram of FIG. 3 along the sectional
line BB', and FIG. 5 is a cross-section diagram of FIG. 3 along the
sectional line CC'. As shown in FIGS. 3-5, the multi-domain
vertical alignment liquid crystal display panel 40 includes a top
substrate 42, a bottom substrate 44, a liquid crystal layer 46
having negative liquid crystals disposed between the top substrate
42 and the bottom substrate 44, a first pixel electrode 50, a
second pixel electrode 52, and a third pixel electrode 53 disposed
between the liquid crystal layer 46 and the bottom substrate 44. A
pixel is commonly defined by two data lines (not shown) and two
scan lines (not shown).
[0024] Multi-domain vertical alignment liquid crystal display panel
40 includes a common electrode 48 formed on the surface of the top
substrate 42, a plurality of color filters (not shown) disposed
between the top substrate 42 and the common electrode 48, a
plurality of protrusions 56 disposed with respect to the first
pixel electrode 50, the second pixel electrode 52, the third pixel
electrode 53, and two rectangular bridge electrodes 54 electrically
connected to the first pixel electrode 50, the second pixel
electrode 52, and the third pixel electrode 53. A capacitor 64 is
formed on the surface of the bottom substrate 44. A planarizing
layer 96 is disposed on the capacitor 64, and a transparent
conductive layer 98 is formed on the planarizing layer 96. The
bridge electrodes 54 can be formed in the same fabrication process
or same layer as the first pixel electrode 50, the second pixel
electrode 52, and the third pixel electrode 53. The shape, size,
depth, and width of the bridge electrodes 54 can be adjusted
according to the design of the product, which are all within the
scope of the present invention.
[0025] The first pixel electrode 50, the second pixel electrode 52,
and the third pixel electrode 53 are preferably transparent
electrodes composed of indium tin oxide or indium zinc oxide, such
as the transparent conductive layer 98, or reflective electrodes
composed of reflecting metals. Additionally, a main slit 60 is
formed between the first pixel electrode 50 and the second pixel
electrode 52, and between the second pixel electrode 52 and the
third pixel electrode 53 respectively, in which main slits 60 are
formed among the bridge electrodes 54, the first pixel electrode 50
and the second pixel electrode 52, or among the bridge electrodes
54, the second pixel electrode 52 and the third pixel electrode
53.
[0026] It should be noted that the capacitor 64 of the present
invention is formed on the bottom substrate 44 corresponding to the
main slit 60. The capacitor 64 is preferably composed of a top
capacitor electrode 70, a bottom capacitor electrode 66, and a
dielectric layer 68 disposed between the two electrodes 70 and 66.
The top capacitor electrode 70 is connected to the drain of the
thin film transistors (not shown) disposed on the bottom substrate
44, in which the top capacitor electrode 70 and/or the bottom
capacitor electrode 66 partially overlaps the main slit 60. In
other words, by forming the capacitor 64 in a position
corresponding to the main slit 60, the present invention is able to
improve the problem of light leakage with respect to the main slit
region, thus increasing the transmittance and usability of the
pixels.
[0027] Please refer to FIG. 6. FIG. 6 illustrates a plan view of a
pixel of a multi-domain vertical alignment liquid crystal display
panel according to an embodiment of the present invention. As shown
in FIG. 6, this embodiment includes a first pixel electrode 74, a
second pixel electrode 76, a third pixel electrode 86, a bridge
electrode 72 connecting the first pixel electrode 74 and the second
pixel electrode 76, a bridge electrode 88 connecting the second
pixel electrode 76 and the third pixel electrode 86, and a
plurality of protrusions 84 disposed corresponding to the pixel
electrodes.
[0028] The first pixel electrode 74, the second pixel electrode 76,
and the third pixel electrode 86 are preferably transparent
electrodes composed of indium tin oxide or indium zinc oxide or
reflective electrodes composed of reflecting metals. A first main
slit 92 is formed among the first pixel electrode 74, the second
pixel electrode 76 and the bridge electrode 72, a second main slit
94 is formed among the second pixel electrode 76, the third pixel
electrode 86 and the bridge electrode 88. Preferably, the first
main slit 92 (or the bridge electrode 72) includes a slant (not
shown) formed between the central portion 78 and two end portion
80. Additionally, a capacitor 90 is disposed corresponding to the
position of the main slit 92.
[0029] In contrast to the rectangular bridge electrodes, the bridge
electrode 72 formed between the first pixel electrode 74 and the
second pixel electrode 76 includes a central portion 78 and two end
portion 80, in which the width W of each of the end portion 80 is
greater than the width w of the central portion 78. The bridge
electrode 72 or 88 can also be formed in the same fabrication
process or same layer as the first pixel electrode 74 and the
second pixel electrode 76. The shape, size, depth, and width of the
bridge electrodes 72 or 88 can also be adjusted according to the
design of the product, which are all within the scope of the
present invention.
[0030] Specifically, the present invention not only forms the
capacitor 90 in a spot corresponding to the location of the main
slit to increase the transmittance and utilization of the pixels,
but also forms a bridge electrode 72 with a shrinking pattern to
improve the problem of unstable arrangement of liquid crystals
caused by conventional rectangular design of the bridge
electrodes.
[0031] Overall, the present invention forms the capacitor in a
position relative to the main slit that is formed between two pixel
electrodes. By using this design, the capacitor can be used to
reduce the problem of light leakage with respect to the main slit
region during dark state and increase the transmittance and
utilization of the pixels. Additionally, bridge electrodes with
shrinking patterns can also be incorporated with the design of the
capacitor, in which the shape of the shrinking pattern can be used
to improve unstable alignment of the liquid crystals and increase
the optical property of the display panel.
[0032] Those skilled in the art will readily observe that numerous
modifications and alterations of the device and method may be made
while retaining the teachings of the invention. Accordingly, the
above disclosure should be construed as limited only by the metes
and bounds of the appended claims.
* * * * *