CN110737141A

CN110737141A - Array substrate, liquid crystal display panel and display device

Info

Publication number: CN110737141A
Application number: CN201911063221.2A
Authority: CN
Inventors: 宋琼; 方丽婷; 吴玲; 沈柏平
Original assignee: Xiamen Tianma Microelectronics Co Ltd
Current assignee: Xiamen Tianma Microelectronics Co Ltd
Priority date: 2019-10-31
Filing date: 2019-10-31
Publication date: 2020-01-31

Abstract

The invention discloses array substrates, a liquid crystal display panel and a display device, wherein a pixel electrode or a common electrode comprises a plurality of strip electrodes, a slit is arranged between adjacent strip electrodes, the width of the electrode is not equal to that of the slit, and the flexoelectric effect can be reduced because the width of the electrode is not equal to that of the slit.

Description

Array substrate, liquid crystal display panel and display device

Technical Field

The invention relates to the technical field of display, in particular to array substrates, a liquid crystal display panel and a display device.

Background

In Fringe Field Switching (FFS) technology, a pixel electrode and a common electrode are formed on the same substrate, wherein the pixel electrode is formed by a plurality of stripe electrodes arranged at intervals, and FFS technology has the advantages of a wide viewing angle of , no color-shift, and the like, and is currently widely used in display panels by .

In the display panel adopting the FFS design, the common voltage is negative in the display panel because the feed through voltage (Feedthrough) pulls the common voltage in a negative direction. However, in some display panels, although a feed-through (feed-through) voltage is also present, the common voltage is positive. However, the conventional driver ICs are designed for the case where the common voltage is negative, and for the display panel where the common voltage is positive, the conventional driver ICs do not support the case and the driver ICs need to be redesigned, which greatly increases the production cost.

Disclosure of Invention

In view of this, the embodiments of the invention provide array substrates, lcd panels and display devices to solve the problem of positive common voltage in the prior art.

The array substrates provided by the embodiment of the invention comprise a substrate, a common electrode and a pixel electrode which are positioned at the side of the substrate and are mutually insulated;

the pixel electrode or the common electrode comprises a plurality of strip-shaped electrodes extending along an th direction, and the strip-shaped electrodes are arranged side by side along a second direction, wherein the th direction is not parallel to the second direction;

in the plurality of strip-shaped electrodes, a slit is arranged between any two adjacent strip-shaped electrodes, and the electrode width of the strip-shaped electrodes in the direction perpendicular to the extending direction of the strip-shaped electrodes is not equal to the slit width of the slit in the direction perpendicular to the extending direction of the slit.

Correspondingly, the embodiment of the invention further provides liquid crystal display panels, which include any array substrate provided by the embodiment of the invention, an opposite substrate arranged opposite to the array substrate, and a liquid crystal layer located between the array substrate and the opposite substrate.

Correspondingly, the embodiment of the invention also provides display devices, which comprise the liquid crystal display panel provided by the embodiment of the invention.

The invention has the following beneficial effects:

according to the array substrates, the liquid crystal display panel and the display device provided by the embodiment of the invention, the pixel electrodes or the common electrodes comprise a plurality of strip-shaped electrodes, the slits are arranged between the adjacent strip-shaped electrodes, and the electrode width is not equal to the slit width.

Drawings

FIG. 1 is a schematic diagram illustrating the flexoelectric effect provided by an embodiment of the present invention;

FIG. 2 is a second schematic diagram illustrating the flexoelectric effect according to the embodiment of the present invention;

FIG. 3 is a schematic cross-sectional view of an array substrate according to embodiments of the present invention;

fig. 4 is a schematic structural diagram of a pixel electrode according to embodiments of the present invention;

FIG. 5 is a graph showing the variation of the percentage of difference between positive and negative frame transmittances T% with time according to different w _ s;

FIG. 6 is a graph showing the change of the transmittance difference percentage of positive and negative frames with time according to the number of strip electrodes;

FIG. 7 is a schematic diagram illustrating a pixel electrode according to another embodiment of the present invention;

fig. 8 is a schematic structural diagram of a pixel electrode according to yet another embodiment of the present invention;

FIG. 9 is a schematic structural diagram of an array substrate according to embodiments of the present invention;

FIG. 10 is a schematic structural diagram of an array substrate according to another embodiments of the present invention;

fig. 11 is a schematic structural diagram of a liquid crystal display panel according to an embodiment of the invention;

fig. 12 is a schematic structural diagram of a display device according to an embodiment of the present invention.

Detailed Description

As is well known, in the FFS electrode structure, due to slits in the electrode structure, liquid crystal molecules have a Flexoelectric Effect (Flexoelectric Effect), which is a phenomenon that the liquid crystal molecules are self-polarized and show a macroscopic electric dipole moment due to the spreading/bending deformation of the liquid crystal molecules under the action of an external electric field, specifically, taking the pixel electrode 2 positioned above the common electrode 1 as an example, as shown in FIG. 1, FIG. 1 is of a schematic diagram of the Flexoelectric Effect provided by the embodiment of the invention, when a frame is positive, the liquid crystal transmittance is increased when the electric dipole moment direction of the liquid crystal molecules above the pixel electrode 2 is upward and the electric field direction is the same, the electric dipole moment direction of the liquid crystal molecules above the slits is downward and the electric field direction is opposite, the liquid crystal transmittance is reduced, when the boundary between the pixel electrode 2 and the slits, the liquid crystal molecules are bent, the electric dipole moment direction penetrates downward and the liquid crystal transmittance is unchanged, as shown in FIG. 2, the schematic diagram of the electric dipole moment direction of the electric Effect provided by the embodiment of the invention is downward, when the frame is negative, the electric dipole moment direction of the liquid crystal molecules above the pixel electrode 2 is the electric dipole moment direction and the electric field direction is opposite, the electric dipole moment of the electric field direction is upward and the electric field direction is not reduced, the liquid crystal molecules above the electric dipole moment of the liquid crystal molecules above the electric field direction is the electric dipole moment.

The flexoelectric effect of the liquid crystal is greatly influenced on the common voltage (Vcom), because the feed-through voltage exists, when the voltage △ V1 between the common electrode and the pixel electrode in the positive frame is equal to the voltage △ V2 between the common electrode and the pixel electrode in the negative frame, that is, Vcom is 0V, and the transmittance T1 of the positive frame is less than the transmittance T2 of the negative frame, that is, T1< T2, when the transmittance T1 of the positive frame is adjusted to be equal to the transmittance T2 of the negative frame, the voltage △ V1 between the common electrode and the pixel electrode in the positive frame is greater than the voltage △ V2 between the common electrode and the pixel electrode in the negative frame, that is, Vcom <0V, while the flexoelectric effect makes the brightness of the positive frame greater than the brightness of the negative frame, in order to adjust the brightness of the positive frame to be equal to the brightness of the negative frame, the voltage △ V1 between the common electrode and the pixel electrode in the positive frame is less than the voltage △, so that the influence on the common voltage is avoided, and the influence on the voltage △, which the common voltage is greater than the positive voltage, in order to avoid the influence on the display panel.

Accordingly, the embodiment of the invention provides array substrates, liquid crystal display panels and display devices, so as to reduce the flexoelectric effect to avoid the positive common voltage of the display panels.

Specifically, liquid crystal display panels with positive common voltage are taken as research objects at present, and since the flexoelectric coefficients of liquid crystal materials are difficult to measure, the electrode structure for reducing the flexoelectric effect is obtained by adopting different flexoelectric coefficients for simulation.

To make the above objects, features and advantages of the present invention more comprehensible, a step of the present invention will be described in conjunction with the accompanying drawings and examples, however, the exemplary embodiments can be embodied in various forms and should not be construed as limited to the embodiments set forth herein, but rather, the embodiments are provided to make the present invention more comprehensive and complete and to fully convey the concept of the exemplary embodiments to those skilled in the art.

While the invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein, those skilled in the art will appreciate that the description is illustrative only and that the invention is not limited to the embodiments set forth herein.

The following describes a display panel and a display device provided in an embodiment of the present invention with reference to the accompanying drawings.

Referring to fig. 3 and 4, kinds of array substrates provided by the embodiment of the invention are shown, wherein fig. 3 is a schematic cross-sectional structure of kinds of array substrates provided by the embodiment of the invention, fig. 4 is a schematic structural diagram of kinds of pixel electrodes provided by the embodiment of the invention, and the array substrates comprise a substrate 01, a common electrode 02 and a pixel electrode 03 which are insulated from each other and positioned at the side of the substrate 01 ;

as shown in FIG. 4, the pixel electrode 03 or the common electrode 02 comprises a plurality of strip-shaped electrodes 011 extending along the th direction X, and the strip-shaped electrodes 011 are arranged side by side along the second direction Y, wherein the th direction X is not parallel to the second direction Y, wherein the pixel electrode is taken as an example in FIG. 4;

in the plurality of strip-shaped electrodes 011, a slit is arranged between any two adjacent strip-shaped electrodes 011, and the electrode width w of the strip-shaped electrodes 011 in the direction perpendicular to the extending direction of the strip-shaped electrodes is not equal to the slit width s of the slit in the direction perpendicular to the extending direction of the strip-shaped electrodes 011.

In the array substrate provided by the embodiment of the invention, the pixel electrode or the common electrode comprises a plurality of strip-shaped electrodes, and a slit is arranged between adjacent strip-shaped electrodes, but the width of the electrode is not equal to that of the slit. Just because the electrode width is not equal to the slit width, the flexoelectric effect can be reduced. The fact that the flexoelectric effect is reduced means that the positive deviation quantity of the public voltage is reduced, the influence of feed-through voltage on the public voltage is larger than the influence of the flexoelectric effect on the public voltage, and therefore the public voltage of the display panel is prevented from being positive.

Specifically, for example, in the existing vehicle-mounted display screen with a Pixel resolution (PPI) of 150 to 200 and a liquid crystal being a positive liquid crystal with a clearing point of 100 ℃, the common voltage of the vehicle-mounted display screen is positive at 127 gray levels, and for the electrode structure and the liquid crystal of the vehicle-mounted display screen, simulation of multiple sets of flexoelectric coefficients shows that the flexoelectric effects of the 127 gray levels are that the positive frame brightness is greater than the negative frame brightness, that is, the flexoelectric effects enable the common voltage of the 127 gray levels to be positive, and shows that the flexoelectric effects can be reduced when the electrode widths are not equal to the slit widths.

In a specific implementation, in the array substrate provided in the embodiment of the present invention, the pixel electrode may be located between the substrate and the common electrode, or the common electrode may be located between the pixel electrode and the substrate, which is not limited herein.

Optionally, in the array substrate provided in the embodiment of the present invention, as shown in fig. 4, the slit widths s between any two adjacent strip-shaped electrodes 011 in the plurality of strip-shaped electrodes 011 are equal; the electrode widths w of the strip electrodes 011 in the plurality of strip electrodes 011 are equal. So as to ensure that the electric field distribution corresponding to each slit in the pixel region is the same, and the electric field distribution corresponding to each strip electrode is the same.

It should be noted that, in the array substrate provided in the embodiment of the present invention, the common electrode may include a plurality of stripe electrodes, or the pixel electrode may include a plurality of stripe electrodes, which is not limited herein, in the drawings of the specification, the example where the pixel electrode includes a plurality of stripe electrodes is illustrated.

Specifically, in the embodiment of the present invention, in order to reduce the flexoelectric effect as much as possible, simulation simulations are performed using different strip electrode widths w and slit widths s, a change curve of the positive frame transmittance difference percentage T% and the negative frame transmittance difference percentage T% with time corresponding to different w _ s is shown in fig. 5, and fig. 5 is a change curve of the positive frame transmittance difference percentage T% and the negative frame transmittance difference percentage T% with time corresponding to different w _ s. Here, the transmittance difference percentage is (average transmittance in positive frame-average transmittance in negative frame)/[ (average transmittance in negative frame + average transmittance in positive frame)/2 ]. As can be seen from fig. 5, the larger the difference between the electrode width and the slit width, the smaller the value of T%, i.e., the smaller the difference between the positive frame luminance and the negative frame luminance, the smaller the flexoelectric effect, and the smaller the positive shift of the common voltage.

For further step verification, four general sets of flexoelectric coefficients were used for simulation, each sets of flexoelectric liquid crystal display panels were simulated with different electrode widths w and slit widths s, and the corresponding average transmittance difference percentage is shown in table 1 below, where the average transmittance difference percentage is (average transmittance of positive frame-average transmittance of negative frame)/[ (average transmittance of negative frame + average transmittance of positive frame)/2 ].

TABLE 1

As can be seen from the simulation results in table 1, the larger the difference between the electrode width and the slit width is, the smaller the value of the average transmittance difference percentage T%, that is, the smaller the difference between the positive frame luminance and the negative frame luminance is, the smaller the flexoelectric effect is, and the smaller the positive shift of the common voltage is.

Therefore, in practical implementation, the width of the strip-shaped electrode may be set to be larger than the width of the slit, and of course, the width of the slit may be set to be larger than the width of the strip-shaped electrode, which is not limited herein.

Specifically, from the results in table 1, it is understood that, in the simulation of four sets of flexoelectric coefficients, the larger the difference between the electrode width and the slit width is, the tendency that the flexoelectric effect is decreased.

Optionally, in the array substrate provided in the embodiment of the present invention, the width of the slit is set to be greater than the width of the strip-shaped electrode, and a ratio of the electrode width of the strip-shaped electrode to the slit width of the slit is less than or equal to 0.8, so as to ensure that a difference between the electrode width and the slit width is as large as possible.

Optionally, in the array substrate provided in the embodiment of the present invention, an electrode width of the strip-shaped electrode is less than or equal to 2.7 micrometers. For example, in table 1, when the flexoelectric coefficient is 3.3 — 5.0, and when w _ s (stripe electrode width — slit width) is 3.0 — 3.1 (micrometers), the average transmittance difference percentage is 1.96%, and the flexoelectric effect is maximum; when w _ s is 2.7_3.5, the average percent difference in transmittance can be reduced to 1.29%; when w _ s is 2.6_3.5, the average percent difference in transmittance may be reduced to 1.05%. When the flexoelectric coefficient is 15 — 15, when w _ s is 3.0 — 3.1 (micrometers), the average transmittance difference percentage is 7.98%, and the flexoelectric effect is maximum; when w _ s is 2.7_3.4, the average percent difference in transmittance may be reduced to 5.69%; when w _ s is 2.6_3.5, the average percent difference in transmittance may be reduced to 4.91%.

Optionally, in the array substrate provided in the embodiment of the present invention, the width of the strip-shaped electrode is set to be greater than the width of the slit, but a ratio of the width of the slit to the width of the strip-shaped electrode is less than or equal to 0.9, so as to ensure that a difference between the width of the electrode and the width of the slit is as large as possible.

Optionally, in the array substrate provided in the embodiment of the present invention, an electrode width of the strip-shaped electrode is greater than or equal to 3.2 micrometers. For example, in table 1, when the flexoelectric coefficient is 3.3 — 13.6, and w _ s is 2.9 — 3.2, the average transmittance difference percentage is 4.88%, and the flexoelectric effect is maximum; when w _ s is 3.2_2.9, the average percent difference in transmittance may be reduced to 2.10%; when w _ s is 3.3_2.8, the average percent difference in transmittance can be reduced to 1.86%; when w _ s is 3.4_2.7, the average percent difference in transmittance may be reduced to 1.39%. When the flexoelectric coefficient is 0_10, when w _ s is 2.9_3.2 (micrometers), the average transmittance difference percentage is 3.75%, and the flexoelectric effect is maximum; when w _ s is 3.2_2.9, the average percent difference in transmittance may be reduced to 0.99%; when w _ s is 3.3_2.8, the average percent difference in transmittance may be reduced to 0.68%; when w _ s is 3.4_2.7, the average percent difference in transmittance may be reduced to 0.23%.

Further , during the study, it was found that not only the difference between the electrode width and the slit width affects the flexoelectric effect, but also the number of stripe-shaped electrodes has a direct effect on the flexoelectric effect.

Specifically, simulation is performed by using 7 strip electrodes, 6 strip electrodes and 5 strip electrodes respectively with different flexoelectric coefficients, w _ s corresponding to the 7 strip electrodes is 3.0_3.1, w _ s corresponding to the 6 strip electrodes is 3.6_3.6, and w _ s corresponding to the 5 strip electrodes is 4.4_ 4.4. Fig. 6 shows a time-dependent change curve of the positive and negative frame transmittance difference percentage T% corresponding to different numbers of strip-shaped electrodes, and fig. 6 shows a time-dependent change curve of the positive and negative frame transmittance difference percentage T% corresponding to different numbers of strip-shaped electrodes. As can be seen from fig. 6, the smaller the number of stripe electrodes, the smaller the corresponding average transmittance difference percentage, that is, the smaller the difference between the positive frame luminance and the negative frame luminance, the smaller the flexoelectric effect, and the smaller the positive shift of the common voltage.

For step verification, four sets of conventional flexoelectric coefficients are used for simulation, and each sets of liquid crystal display panels with different numbers of strip-shaped electrodes are used for simulation, and the specific simulation results are shown in table 2 below.

TABLE 2

As can be seen from the results in table 2, the smaller the number of stripe electrodes, the smaller the corresponding average transmittance difference percentage, that is, the smaller the difference between the positive frame luminance and the negative frame luminance, the smaller the flexoelectric effect, and the smaller the positive shift of the common voltage.

Therefore, optionally, in the array substrate provided in the embodiment of the present invention, the pixel electrode or the common electrode includes N strip-shaped electrodes, where N is greater than 4 and less than 8.

, in the array substrate according to the embodiment of the present invention, N is equal to 5 or 6. from the results of table 2 above, when the number of the strip electrodes is 5 or 6, the corresponding average transmittance difference percentage can be significantly reduced, so that the flexoelectric effect is significantly reduced to reduce the positive bias of the common voltage.

Alternatively, in the array substrate according to the embodiment of the present invention, as shown in fig. 7, fig. 7 is a schematic structural diagram of a pixel electrode according to another embodiment of the present invention, and a corner 012 is further disposed at the end of each strip electrode 011, so that when the display panel is pressed, the indentation will disappear relatively quickly, i.e., Trace mura is improved.

, in the array substrate according to the embodiment of the present invention, as shown in fig. 8, fig. 8 is a schematic structural view of the pixel electrode according to another embodiment of the present invention, and a lateral electrode 013 is further provided, wherein corners 012 at the ends of each strip electrode 011 are connected by the lateral electrode 013, so that an electric field and thus liquid crystal molecules have included angles, and the liquid crystal molecules can rotate at fixed degrees, thereby reducing dark areas.

In practical implementation, in order to improve the viewing angle, a double-domain structure is usually adopted in the array substrate provided by the embodiment of the present invention, as shown in fig. 9, fig. 9 is a schematic structural diagram of the array substrate provided by another embodiments of the present invention, that is, strip-shaped electrodes 011 include two linear portions 010 symmetrically arranged, and a corner 012 is arranged at the end of each linear portion 010.

, as shown in fig. 10, fig. 10 is a schematic structural diagram of an array substrate according to the present invention, wherein of the array substrate is provided with a plurality of gate lines gate and data lines data crossing each other and located on a substrate facing a common electrode side, the plurality of gate lines gate and data lines data crossing each other to define a plurality of pixel regions, a thin film transistor (not shown) is disposed in each pixel region, and each common electrode or each pixel electrode 03 of the pixel regions includes a plurality of strip electrodes 011.

Optionally, in the array substrate provided in the embodiment of the invention, as shown in fig. 10, the data line data extends along the th direction X, and the gate line gate extends along the second direction Y.

Specifically, in the embodiment of the present invention, the th direction is a column direction, and the second direction is a row direction.

Based on the same concept of , the embodiment of the present invention further provides types of liquid crystal display panels, as shown in fig. 11, fig. 11 is a schematic structural view of the liquid crystal display panel provided by the embodiment of the present invention, and the liquid crystal display panel includes any array substrate 10 provided by the embodiment of the present invention, an opposite substrate 20 disposed opposite to the array substrate 10, and a liquid crystal layer 30 disposed between the array substrate 10 and the opposite substrate 20.

Based on the same concept as , the embodiment of the present invention further provides display devices, including any liquid crystal display panel provided in the embodiment of the present invention, where the display device may be any product or component having a display function, such as a mobile phone, a tablet computer, a television, a display, a notebook computer, a digital photo frame, a navigator, and the like shown in fig. 12.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.

Claims

The array substrates are characterized by comprising a substrate base plate, a common electrode and a pixel electrode, wherein the common electrode and the pixel electrode are positioned on the side of the substrate base plate and are mutually insulated;

the pixel electrode or the common electrode comprises a plurality of strip-shaped electrodes extending along an th direction, and the strip-shaped electrodes are arranged side by side along a second direction, wherein the th direction is not parallel to the second direction;

in the plurality of strip-shaped electrodes, a slit is arranged between any two adjacent strip-shaped electrodes, and the electrode width of the strip-shaped electrodes in the direction perpendicular to the extending direction of the strip-shaped electrodes is not equal to the slit width of the slit in the direction perpendicular to the extending direction of the slit.
2. The array substrate of claim 1,

the slit widths between any two adjacent strip-shaped electrodes in the strip-shaped electrodes are equal;

the electrode widths of the strip-shaped electrodes in the plurality of strip-shaped electrodes are equal.
3. The array substrate of claim 2,

the ratio of the electrode width of the strip-shaped electrode to the slit width of the slit is less than or equal to 0.8.
4. The array substrate of claim 3,

the electrode width of the strip-shaped electrodes is less than or equal to 2.7 micrometers.
5. The array substrate of claim 2,

the ratio of the slit width of the slit to the electrode width of the strip-shaped electrode is less than or equal to 0.9.
6. The array substrate of claim 5,

the electrode width of the strip-shaped electrodes is greater than or equal to 3.2 micrometers.
7. The array substrate of claim 1,

the pixel electrode or the common electrode includes N stripe-shaped electrodes, where N is greater than 4 and less than 8.
8. The array substrate of claim 7,

n is equal to 5 or 6.
9. The array substrate of claim 1,

a data line and a gate line on a side of the substrate facing the common electrode ;

the data line extends in the th direction, and the gate line extends in the second direction.
10, LCD panel, comprising the array substrate of any of claims 1-9, an opposite substrate disposed opposite to the array substrate, and a liquid crystal layer between the array substrate and the opposite substrate.
A display device of claim 11, , comprising the liquid crystal display panel of claim 10.