U.S. patent application number 15/667123 was filed with the patent office on 2017-11-16 for thin film transistor-liquid crystal display device and its driving method.
The applicant listed for this patent is BEIJING BOE OPTOELECTRONICS TECHNOLOGY CO., LTD., BOE TECHNOLOGY GROUP CO., LTD.. Invention is credited to Ming CHEN, Dan WANG.
Application Number | 20170330522 15/667123 |
Document ID | / |
Family ID | 42098532 |
Filed Date | 2017-11-16 |
United States Patent
Application |
20170330522 |
Kind Code |
A1 |
CHEN; Ming ; et al. |
November 16, 2017 |
THIN FILM TRANSISTOR-LIQUID CRYSTAL DISPLAY DEVICE AND ITS DRIVING
METHOD
Abstract
The invention discloses a TFT-LCD and its driving method,
TFT-LCD comprises an array substrate and a color filter substrate,
a common electrode on said color filter substrate being divided
into multiple columns, each of which corresponding to one column of
pixels; on color filter substrate, odd number columns are first
common electrodes, even number columns are second common
electrodes; difference between voltages input to said first common
electrodes and said second common electrodes is larger than zero
and less than dynamic range of driving voltage of liquid crystal
driving voltage-transmittance curve. By setting two common
electrode voltages, TFT-LCD and its driving method provided by the
invention can make dynamic range of input voltage required for
driving liquid crystal display device be smaller than dynamic range
of driving voltage of liquid crystal driving voltage-transmittance
curve, thus reducing power consumption during driving the liquid
crystal.
Inventors: |
CHEN; Ming; (Beijing,
CN) ; WANG; Dan; (Beijing, CN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
BOE TECHNOLOGY GROUP CO., LTD.
BEIJING BOE OPTOELECTRONICS TECHNOLOGY CO., LTD. |
Beijing
Beijing |
|
CN
CN |
|
|
Family ID: |
42098532 |
Appl. No.: |
15/667123 |
Filed: |
August 2, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12574836 |
Oct 7, 2009 |
9740057 |
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15667123 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G02F 2001/134318
20130101; G02F 2201/121 20130101; G09G 3/3614 20130101; G02F
1/134336 20130101; G09G 2300/0426 20130101; G02F 1/133514 20130101;
G09G 2330/021 20130101; G09G 3/3655 20130101; G02F 1/1368
20130101 |
International
Class: |
G09G 3/36 20060101
G09G003/36; G02F 1/1335 20060101 G02F001/1335; G09G 3/36 20060101
G09G003/36; G02F 1/1343 20060101 G02F001/1343; G02F 1/1368 20060101
G02F001/1368 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 10, 2008 |
CN |
200810223760.3 |
Claims
1. A thin film transistor-liquid crystal display device comprising
an array substrate and a color filter substrate, wherein common
electrodes on said color filter substrate form an array
corresponding to pixels; on said color filter substrate, each of
the common electrodes in an intersection of an odd number column
and an odd number row of the array and each of the common
electrodes in an intersection of an even number column and an even
number row of the array are set as first common electrodes; each of
the common electrodes in an intersection of the odd number column
and the even number row of the array and each of the common
electrodes in an intersection of the even number column and the odd
number row of the array are set as second common electrodes;
absolute difference between voltages input to said first common
electrodes and said second common electrodes is larger than zero
and less than a dynamic range of a driving voltage of a liquid
crystal driving voltage-transmittance curve.
2. A driving method for the thin film transistor-liquid crystal
display device according to claim 1, wherein the driving method
comprises: during the thin film transistor-liquid crystal display
device displaying a frame, first common electrode voltage signal is
input to said first common electrodes while second common electrode
voltage signal is input to said second common electrodes; and a
positive directional driving voltage signal of a first driving
voltage-transmittance curve corresponding to said first common
electrode voltage is input to odd number columns of data lines for
the odd number rows and even number columns of data lines for the
even number rows on said array substrate of said thin film
transistor-liquid crystal display device, while a negative
directional driving voltage signal of a second driving
voltage-transmittance curve corresponding to said second common
electrode voltage is input to even number columns of data lines for
the odd number rows and odd number columns of data lines for the
even number rows on said array substrate of said thin film
transistor-liquid crystal display device; during the thin film
transistor-liquid crystal display device displaying a next adjacent
frame, said second common electrode voltage signal is input to said
first common electrodes while said first common electrode voltage
signal is input to said second common electrodes; and said negative
directional driving voltage signal of said second driving
voltage-transmittance curve corresponding to said second common
electrode voltage is input to the odd number columns of data lines
for the odd number rows and the even number columns of data lines
for the even number rows on said array substrate of said thin film
transistor-liquid crystal display device, while said positive
directional driving voltage signal of said first driving
voltage-transmittance curve corresponding to said first common
electrode voltage is input to the even number columns of data lines
for the odd number rows and the odd number columns of data lines
for the even number rows on said array substrate of said thin film
transistor-liquid crystal display device.
Description
TECHNICAL FIELD OF THE INVENTION
[0001] The present invention relates to the field of liquid crystal
display, and to a TFT (Thin Film Transistor) Liquid Crystal Display
device and its driving method.
BACKGROUND OF THE INVENTION
[0002] Liquid crystals in a TFT-LCD (Liquid Crystal Display) are
sandwiched by an array substrate on which there are a TFT and a
pixel electrode, and a color filter substrate on which there are a
color resin and a common electrode, wherein the liquid crystals
inverse when a voltage is applied between the common electrode and
the pixel electrode. For a LCD of normally white mode, the less the
voltage difference between two sides of liquid crystals is, the
larger the transmittance of the liquid crystal molecules are. When
a voltage is applied between two sides of the liquid crystal
molecules, the liquid crystal molecules rotate, thus making a light
provided by a backlight transmitting out through the liquid crystal
molecule, wherein the amount of the light transmitted out is
determined by rotation angle of the liquid crystal molecules. Due
to the property of the liquid crystal molecules itself, if driving
with a voltage of only one polarity, the liquid crystal molecules
is extremely vulnerable to aging, thus shortening the lifetime of
the liquid crystal molecule. Therefore, in order to prevent it from
aging, it is necessary to drive the liquid crystal molecules in
such a way that voltages of positive polarity and negative polarity
are alternately used for driving.
[0003] A structural schematic diagram of a TFT in the prior art is
as shown in FIG. 1, wherein when the gate line 101 apply a turn-on
voltage to the gate 102, the TFT is in an ON state. Data line 103
is connected to the source 104 of the TFT, while the drain 105 of
the TFT is connected to the pixel electrode (not shown in FIG. 1).
The voltage difference between the pixel electrode and the common
electrode set on the color filter substrate drives the liquid
crystal molecules to inverse. The common electrode is applied a
common electrode voltage Vcom. In FIG. 1, pixel capacitor
(C.sub.Lc) 106 is an equivalent capacitor formed between the common
electrode and the pixel electrode. When the TFT is turned on, the
pixel capacitor (C.sub.Lc) 106 is charged through the data line
103. Holding capacitor (C.sub.s) 107 is usually connected in
parallel with the pixel capacitor (C.sub.Lc) 106 to improve its
holding property.
[0004] After the pixel capacitor (C.sub.Lc) 106 has been charged, a
turn-off voltage is supplied to the gate 102 of the TFT through the
gate line 101, the TFT being in an OFF state at this time, and the
voltage already charged to the pixel capacitor (C.sub.Lc) 106 can
be maintained until next time the gate is turned on.
[0005] A schematic diagram of driving for liquid crystal molecules
in the prior art is as shown in FIG. 2. In the Figure, the lateral
axis of measured V-T curve 201 for liquid crystal stands for
Driving Voltage (V), and the longitudinal axis of the V-T curve
stands for Transmittance (T) of the liquid crystal molecules, the
V-T curve being determined by the property of the liquid crystal
itself. After the V-T curve for liquid crystal is measured, it is
needed to determine the dynamic range 202 of driving voltage, and
to determine the common electrode voltage 203 based on the dynamic
range 202. With respect to the LCD of normally white mode, the
lower the voltage difference between the two sides of the liquid
crystal is, the larger the transmittance of the liquid crystal
molecules is. Thus, the common electrode voltage 203 is chosen as
corresponding driving voltage when the transmittance of the liquid
crystal is highest, that is, the common electrode voltage 203 may
be corresponding abscissa at the maximum of the V-T curve 201.
Within the dynamic range 202, the range of the driving voltage
higher than the common electrode voltage is defined as positive
directional driving voltage range 204, and the range of the driving
voltage lower than the common electrode voltage is defined as
negative directional driving voltage range 205. The inversion of
the liquid crystal molecules is determined by the voltage
difference between the positive directional inversion signal
voltage and the common electrode voltage when positive directional
inversion signal within the positive directional driving voltage
range is applied to the source of the TFT; while the inversion of
the liquid crystal molecules is determined by the voltage
difference between the negative directional inversion signal
voltage and the common electrode voltage when negative directional
inversion signal within the negative directional driving voltage
range is applied to the source of the TFT. In this way, when
positive directional driving and negative directional driving, the
angles of the liquid crystal rotating toward positive and negative
directions are same, making its transmittance to light uniform.
[0006] Not only the picture flickering is avoided, but also the
liquid crystal is prevented from aging, on the premise that the
liquid crystal molecules continuously rotates by setting the common
electrode voltage.
[0007] A schematic diagram of the TFT array on the array substrate
in the prior art is as shown in FIG. 3. Presently, when driving TFT
liquid crystal, the inversion manners usually employed are as
follows:
[0008] (1) Frame Inversion:
[0009] That is, the liquid crystal is driven with the voltages of
same polarity in one frame of picture, and with reverse polarity of
voltage in the next adjacent frame of the picture. A schematic
diagram of polarities of voltages between two sides of respective
pixel capacitors in TFT array of respective frames when driving
liquid crystal to inverse by means of the frame inversion according
to the prior art is as shown in FIG. 4.
[0010] (2) Row Inversion
[0011] That is, in one frame of picture, the pixel capacitors on
the same row of gate lines are driven with the voltages of same
polarity, and the pixel capacitors on the adjacent row of gate
lines are driven with the voltages of reverse polarity. A schematic
diagram of polarities of voltages between two sides of respective
pixel capacitors in TFT array of respective frames when driving
liquid crystal to inverse by means of the row inversion according
to the prior art is as shown in FIG. 5.
[0012] (3) Column Inversion
[0013] That is, in one frame of picture, the pixel capacitors on
the same column of gate lines are driven with the voltages of same
polarity, and the pixel capacitors on the adjacent column of gate
lines are driven with the voltages of reverse polarity. A schematic
diagram of polarities of voltages between two sides of respective
pixel capacitors in TFT array of respective frames when driving
liquid crystal to inverse by means of the column inversion
according to the prior art is as shown in FIG. 6.
[0014] (4) Point Inversion
[0015] That is, the polarities of driving voltage of any adjacent
pixel capacitors are different in one frame of picture, and each
pixel capacitor is driven with reverse polarity of voltage in the
next adjacent frame of the picture with respect to the previous
adjacent frame of the picture. A schematic diagram of polarities of
voltage between two sides of respective pixel capacitors in TFT
array of respective frames when driving liquid crystal to inverse
by means of the point inversion according to the prior art is as
shown in FIG. 7.
[0016] There are problems in driving manners for liquid crystal in
the prior art, in that: since one common electrode voltage is
employed, there is only one reference voltage when positive
directional and negative directional driving for liquid crystal, so
that dynamic range of driving voltage is large, as shown in FIG. 2,
wherein the driving voltage needs to vary within the range as large
as described with reference number 202. However, the magnitude of
the range of the driving voltage directly determines the power
consumption of liquid crystal driving circuit portion, driving
manners for liquid crystal in the prior art may thus result in
great power consumption in the course of driving.
SUMMARY OF THE INVENTION
[0017] An embodiment of the present invention is to provide a
liquid crystal display device, which can reduce power consumption
in the course of driving the liquid crystal to inverse, with
respect to the problems in the prior art.
[0018] An embodiment of the present invention provides a thin film
transistor-liquid crystal display device, comprising an array
substrate and a color filter substrate, a common electrode on said
color filter substrate being divided into multiple columns, each of
which corresponding to one column of pixels;
[0019] on said color filter substrate, odd number columns are first
common electrodes, and even number columns are second common
electrodes;
[0020] the difference between voltages input to said first common
electrodes and said second common electrodes is larger than zero
and less than a dynamic range of the driving voltage of a liquid
crystal driving voltage-transmittance curve.
[0021] A driving method for the thin film transistor-liquid crystal
display device may comprise:
[0022] during the thin film transistor-liquid crystal display
device displaying a frame, a first common electrode voltage signal
is input to said first common electrodes while second common
electrode voltage signal is input to said second common electrodes;
and a positive directional driving voltage signal of a first
driving voltage-transmittance curve corresponding to said first
common electrode voltage is input to odd number columns of data
lines on said array substrate of said thin film transistor-liquid
crystal display device, while a negative directional driving
voltage signal of a second driving voltage-transmittance curve
corresponding to said second common electrode voltage is input to
even number columns of data lines on said array substrate of said
thin film transistor-liquid crystal display device;
[0023] during the thin film transistor-liquid crystal display
device displaying a next adjacent frame, said second common
electrode voltage signal is input to said first common electrodes
while said first common electrode voltage signal is input to said
second common electrodes; and said negative directional driving
voltage signal of said second driving voltage-transmittance curve
corresponding to said second common electrode voltage is input to
said odd number columns of data lines on said array substrate of
said thin film transistor-liquid crystal display device, while said
positive directional driving voltage signal of said first driving
voltage-transmittance curve corresponding to said first common
electrode voltage is input to said even number columns of data
lines on said array substrate of said thin film transistor-liquid
crystal display device;
[0024] the difference between voltages input to said first common
electrodes and said second common electrodes is larger than zero
and less than the dynamic range of the driving voltage of the
liquid crystal driving voltage-transmittance curve.
[0025] An embodiment of the present invention also provides a thin
film transistor-liquid crystal display device comprising an array
substrate and a color filter substrate, a common electrode on said
color filter substrate being divided into an array corresponding to
pixels;
[0026] on said color filter substrate, first common electrodes are
set in odd number pixels on odd number rows and even number pixels
on even number rows;
[0027] second common electrodes are set in even number pixels on
odd number rows and odd number pixels on even number rows;
[0028] the difference between voltages input to said first common
electrodes and said second common electrodes is larger than zero
and less than a dynamic range of the driving voltage of a liquid
crystal driving voltage-transmittance curve.
[0029] A driving method for the thin film transistor-liquid crystal
display device comprises:
[0030] during the thin film transistor-liquid crystal display
device displaying a frame, first common electrode voltage signal is
input to said first common electrodes while second common electrode
voltage signal is input to said second common electrodes; and a
positive directional driving voltage signal of a first driving
voltage-transmittance curve corresponding to said first common
electrode voltage is input to odd number columns of data lines for
the odd number rows and even number columns of data lines for the
even number rows on said array substrate of said thin film
transistor-liquid crystal display device, while a negative
directional driving voltage signal of a second driving
voltage-transmittance curve corresponding to said second common
electrode voltage is input to even number columns of data lines for
the odd number rows and odd number columns of data lines for the
even number rows on said array substrate of said thin film
transistor-liquid crystal display device;
[0031] during the thin film transistor-liquid crystal display
device displaying a next adjacent frame, said second common
electrode voltage signal is input to said first common electrodes
while said first common electrode voltage signal is input to said
second common electrodes; and said negative directional driving
voltage signal of said second driving voltage-transmittance curve
corresponding to said second common electrode voltage is input to
the odd number columns of data lines for the odd number rows and
the even number columns of data lines for the even number rows on
said array substrate of said thin film transistor-liquid crystal
display device, while said positive driving voltage signal of said
first driving voltage-transmittance curve corresponding to said
first common electrode voltage is input to the even number columns
of data lines for the odd number rows and the odd number columns of
data lines for the even number rows on said array substrate of said
thin film transistor-liquid crystal display device;
[0032] the difference between voltages input to said first common
electrodes and said second common electrodes is larger than zero
and less than the dynamic range of the driving voltage of the
liquid crystal driving voltage-transmittance curve.
[0033] An embodiment of the present invention further provides a
driving method for a thin film transistor-liquid crystal display
device, comprising:
[0034] during the thin film transistor-liquid crystal display
device displaying a frame, a first common electrode voltage signal
is input to a common electrode on a color filter substrate of said
thin film transistor-liquid crystal display device, and a positive
directional driving voltage signal of a first driving
voltage-transmittance curve corresponding to said first common
electrode voltage is input to respective data lines on an array
substrate of said thin film transistor-liquid crystal display
device;
[0035] during the thin film transistor-liquid crystal display
device displaying a next adjacent frame, second common electrode
voltage signal is input to said common electrode on said color
filter substrate of said thin film transistor-liquid crystal
display device, and a negative directional driving voltage signal
of a second driving voltage-transmittance curve corresponding to
said second common electrode voltage is input to said respective
data lines on said array substrate of said thin film
transistor-liquid crystal display device;
[0036] the difference between voltages input to said first common
electrodes and said second common electrodes is larger than zero
and less than the dynamic range of the driving voltage of the
liquid crystal driving voltage-transmittance curve.
[0037] The thin film transistor-liquid crystal display device and
its driving method provided by the embodiments of the present
invention set a first common electrode voltage and second common
electrode voltage, and set the difference between the first and the
second common electrode voltages to be larger than zero and less
than dynamic range of the driving voltage of liquid crystal driving
voltage-transmittance curve, thus it may be assured that the
dynamic range of input voltage required for driving the liquid
crystal display device is smaller than the dynamic range of the
driving voltage of the liquid crystal driving voltage-transmittance
curve, reducing the power consumption when driving the liquid
crystal to inverse.
[0038] In the following, by way of accompanying drawings and
embodiments, further detailed description will be made to the
technical schemes of the embodiments of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0039] FIG. 1 is a structural schematic diagram of TFT in the prior
art;
[0040] FIG. 2 is a schematic diagram of driving for liquid crystal
molecules in the prior art;
[0041] FIG. 3 is a schematic diagram of a TFT array on an array
substrate in the prior art;
[0042] FIG. 4 is a schematic diagram of polarities of voltages
between two sides of respective pixel capacitors in TFT array of
respective frames when driving liquid crystal to inverse by means
of the frame inversion according to the prior art;
[0043] FIG. 5 is a schematic diagram of polarities of voltages
between two sides of respective pixel capacitors in TFT array of
respective frames when driving liquid crystal to inverse by means
of the row inversion according to the prior art;
[0044] FIG. 6 is a schematic diagram of polarities of voltages
between two sides of respective pixel capacitors in TFT array of
respective frames when driving liquid crystal to inverse by means
of the column inversion according to the prior art;
[0045] FIG. 7 is a schematic diagram of polarities of voltages
between two sides of respective pixel capacitors in TFT array of
respective frames when driving liquid crystal to inverse by means
of the point inversion according to the prior art;
[0046] FIG. 8 is a structural schematic diagram of a color filter
substrate in a first embodiment of TFT liquid crystal display
device according to an embodiment of the present invention;
[0047] FIG. 9 is a schematic diagram of a first embodiment of
driving method for TFT liquid crystal display device according to
an embodiment of the present invention;
[0048] FIG. 10 is a schematic diagram of a second embodiment of
driving method for TFT liquid crystal display device according to
an embodiment of the present invention;
[0049] FIG. 11 is a structural schematic diagram of a color filter
substrate in a second embodiment of TFT liquid crystal display
device according to an embodiment of the present invention.
DESCRIPTION OF THE EMBODIMENTS
[0050] Liquid crystal display device uses lattice mode to display
image of certain resolution. In the liquid crystal display device,
one TFT, a pixel electrode and a common electrode set on a color
filter substrate may constitute one display unit, which may be
referred to as one pixel.
[0051] A structural schematic diagram of a color filter substrate
in a first embodiment of TFT liquid crystal display device
according to an embodiment of the present invention. Within the
color filter substrate, the common electrode is divided into
multiple columns, each corresponding to one column of pixels, the
common electrode 11 of odd number columns being connected to a
first transfer electrode point 13, the common electrode 12 of even
number columns being connected to a second transfer electrode point
14. A Black Matrix (BM) 15 is also included in FIG. 8.
[0052] A schematic diagram of a first embodiment of driving method
of TFT liquid crystal display device according to an embodiment of
the present invention is as shown in FIG. 9. In the following the
driving manner of the first embodiment of liquid crystal display
device according to an embodiment of the present invention will be
explained in detail in combination with FIG. 8 and FIG. 9.
[0053] As shown in FIG. 9, firstly, two common electrode voltages,
i.e., a first common electrode voltage V.sub.1 and a second common
electrode voltage V.sub.2 are set, and a first common electrode
voltage signal is input to the first transfer electrode point while
second common electrode voltage signal is input to the second
transfer electrode point. V.sub.1 is the corresponding abscissa at
maximum transmittance of a first V-T curve 301, and V.sub.2 is the
corresponding abscissa at maximum transmittance of a second V-T
curve 302. Since V-T curve for liquid crystal is determined by
property of liquid crystal, and for a liquid crystal display
device, the shape of the V-T curve for its liquid crystal is
certain, and common electrode voltage is the abscissa corresponding
to the point of maximum transmittance of V-T curve, the shapes of
corresponding V-T curves for different common electrode voltages
are identical, with the position of the curves shifting in the
direction of lateral axis.
[0054] Wherein the difference between V.sub.1 and V.sub.2 should be
larger than zero and less than dynamic range of the driving voltage
of the first V-T curve, the beginning point and end point of which
are respectively V.sub.1-1 and V.sub.1-2, and the beginning point
and end point of dynamic range of the driving voltage of the second
V-T curve are respectively V.sub.2-1 and V.sub.2-2. Generally,
because parasitic capacitance exists among gate, source and drains
of TFT, the ranges of positive directional and negative directional
driving voltage in V-T curve are not completely identical.
[0055] During the liquid crystal display device displaying a frame,
on the color filter substrate, the first common electrode voltage
signal is input to the first common electrodes for the odd number
columns of pixels; on the array substrate, the positive directional
driving voltage signal of the first V-T curve, i.e. the voltage
signals within the range from V.sub.1 to V.sub.1-2 of the first V-T
curve as shown in FIG. 9, is input to the odd number columns of
data lines. Since all of the signal voltages within the range from
V.sub.1 to V.sub.1-2 are equal to or larger than signal voltage of
V.sub.1, positive directional voltage is applied between two sides
of the liquid crystal, thus the voltage signals within the range
from V.sub.1 to V.sub.1-2 may be referred to as positive
directional driving voltage signal. Meanwhile, the second common
electrode voltage signal is input to the second common electrodes
for the even number columns of pixels; on the array substrate, the
reverse driving voltage signal of the second V-T curve, i.e. the
voltage signals within the range from V.sub.2-1 to V.sub.2 of the
second V-T curve as shown in FIG. 9, is input to the even number
columns of data lines. Since all of the signal voltages within the
range from V.sub.2-1 to V.sub.2 are equal to or less than signal
voltage of V.sub.2, negative voltage is applied between two sides
of the liquid crystal, thus the voltage signals within the range
from V.sub.2-1 to V.sub.2 may be referred to as negative
directional driving voltage signal.
[0056] During the liquid crystal display device displaying a next
adjacent frame, on the color filter substrate, the second common
electrode voltage signal is input to the first common electrodes
for the odd number columns of pixels, while on the array substrate,
negative directional driving voltage signal of the second V-T curve
is input to the odd number columns of data lines. Meanwhile, the
first common electrode voltage signal is input to the second common
electrodes for the even number columns of pixels, while on the
array substrate, the positive directional driving voltage signal of
the first V-T curve is input to the even number columns of data
lines.
[0057] The column inversion as shown in FIG. 6 can be achieved by
employing the above driving manner. In the above driving manner,
the varying range for the driving voltages input to the first or
second common electrodes is from V.sub.1 to V.sub.2. Because the
difference between V.sub.1 and V.sub.2 is less than dynamic range
of the driving voltage of the first V-T curve, it can be assured
that the dynamic range for the driving voltage signals input to the
first and second common electrodes is smaller than dynamic range of
the driving voltage of the first V-T curve, thus reducing power
consumption in the course of driving the liquid crystal display
device.
[0058] In FIG. 9, the difference between V.sub.1 and V.sub.2 is
less than the dynamic range of the driving voltage of the first V-T
curve, and V.sub.1-2 is less than V.sub.2, and V.sub.2-1 is larger
than V.sub.1. Setting for V.sub.1 and V.sub.2 may be as shown in
FIG. 10, which is a schematic diagram of a second embodiment of
driving method for TFT liquid crystal display device according to
an embodiment of the present invention. In FIG. 10, V.sub.1-2 is
larger than V.sub.2, and V.sub.2-1 is less than V.sub.1 with
assuring that the difference between V.sub.1 and V.sub.2 is larger
than zero and less than the dynamic range of the driving voltage of
the first V-T curve. In such case, the dynamic range for the
driving voltage signals input to the first and second common
electrodes is smaller than dynamic range of the driving voltage of
the first V-T curve as well. In an implementation, the dynamic
range for the driving voltage signals input to the first and second
common electrodes can be made close to the larger one of positive
directional or negative directional dynamic range of the driving
voltages of the first V-T curve, thus better reducing the power
consumption in the course of driving the liquid crystal display
device.
[0059] A structural schematic diagram of a color filter substrate
in a second embodiment of TFT liquid crystal display device
according to an embodiment of the present invention is as shown in
FIG. 11. On the color filter substrate, the common electrode is
divided into the array corresponding to the pixels, and the first
common electrodes 21 is set in the odd number pixels on the odd
number rows and the even number pixels on the even number rows
while the second common electrodes 22 is set in the even number
pixels on the odd number rows and the odd number pixels on the even
number row. The common electrode on the color filter substrate is
obtained by way of deposition so that in order to implement the
structure of the color filter substrate in the second embodiment,
it is possible to connect the common electrodes for odd number
pixels on the odd number rows and the even number pixels on the
even number rows, further connect to the first transfer electrode
point 23 and input the first common electrode voltage; and to
connect the common electrodes for even number pixels on the odd
number rows and the odd number pixels on the even number rows,
further connect to the second transfer electrode point 24 and input
the second common electrode voltage.
[0060] During the liquid crystal display device displaying a frame,
the first common electrode voltage signal is input to the first
transfer electrode point, i.e., to all of the first common
electrodes, while the second common electrode voltage signal is
input to the second transfer electrode point, i.e. to all of the
second common electrodes. Also, the positive directional driving
voltage signal of the first V-T curve corresponding to the first
common electrode voltage is input to the odd number columns of data
lines for the odd number rows and the even number columns of data
lines for the even number rows on the array substrate of the liquid
crystal display device, while the negative directional driving
voltage signal of the second V-T curve corresponding to the second
common electrode voltage is input to the even number columns of
data lines for the odd number rows and the odd number columns of
data lines for the even number rows on the array substrate of the
liquid crystal display device.
[0061] During the liquid crystal display device displaying the next
adjacent frame, the second common electrode voltage signal is input
to the first transfer electrode point, i.e., to all of the first
common electrodes, while the first common electrode voltage signal
is input to the second transfer electrode point, i.e., to all of
the second common electrodes. Also, the negative directional
driving voltage signal of the second V-T curve corresponding to the
second common electrode voltage is input to the odd number columns
of data lines for the odd number rows and the even number columns
of data lines for the even number rows on the array substrate of
the liquid crystal display device, while the positive directional
driving voltage signal of the first V-T curve corresponding to the
first common electrode voltage is input to the even number columns
of data lines for the odd number rows and the odd number columns of
data lines for the even number rows on the array substrate of the
liquid crystal display device.
[0062] With the structure of the color filter substrate as shown in
FIG. 11, the point inversion as shown in FIG. 7 can be achieved.
Setting the difference between the first and the second common
electrode voltages to be larger than zero and less than the dynamic
range of the driving voltage of the first V-T curve can assure that
the dynamic range of input voltage required for driving the liquid
crystal display device consisting of the color filter substrate as
shown in FIG. 11 is smaller than the dynamic range of the driving
voltage of the first V-T curve, thus reducing the power consumption
when driving the liquid crystal display device.
[0063] In the prior art, a common electrode is usually a layer of
ITO (Indium-tin oxide) deposited on a color filter substrate, that
is to say, the common electrodes are integration as a whole. With
respect to the liquid crystal display device of such structure, the
way of performing driving by setting two common electrodes can be
that:
[0064] During the liquid crystal display device displaying a frame,
the first common electrode voltage signal is input to the common
electrode on the color filter substrate, and the positive
directional driving voltage signal of the first V-T curve
corresponding to the first common electrodes is input to respective
data lines on the array substrate;
[0065] During the liquid crystal display device displaying the next
adjacent frame, the second common electrode voltage signal is input
to the common electrode on the color filter substrate, and the
negative directional driving voltage signal of the second V-T curve
corresponding to the second common electrodes is input to
respective data lines on the array substrate.
[0066] The frame inversion can be achieved by means of such driving
manner. Setting the difference between the first and the second
common electrode voltages to be larger than zero and less than the
dynamic range of the driving voltage of the first V-T curve can
assure that the dynamic range of input voltage required for driving
the liquid crystal display device in the prior art is smaller than
the dynamic range of the driving voltage of the first V-T curve,
thus reducing the power consumption when driving the liquid crystal
display device.
[0067] Finally, it should be noted that the above embodiments is
only for explaining the technical solutions of the embodiments of
the present invention, and not for limiting. Although the
embodiments of the present invention have been described in details
with reference to the embodiments, those skilled in the art should
be appreciated that the technical solutions of the present
invention still can be modified or equivalently replaced; and these
modifications or equivalent replacements will not make the modified
technical solution departing from the spirit and scope of the
technical solution of the present invention.
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