CN103123423B - Liquid crystal display panel and pixel driving method thereof - Google Patents

Abstract

A liquid crystal display panel and a pixel driving method thereof. The liquid crystal display panel comprises a substrate, an opposite substrate and a liquid crystal layer. The substrate has a common electrode. The opposite substrate is arranged opposite to the substrate and is provided with a plurality of pixel electrodes corresponding to the pixels of the liquid crystal display panel. The liquid crystal layer is arranged between the substrate and the opposite substrate and is provided with a plurality of liquid crystal molecules. When the liquid crystal molecules are switched, two different levels of voltage are applied to the pixel electrode, and a specific level of common voltage is applied to the common electrode. The common voltage of a particular level is between the voltages of two different levels. In addition, a pixel driving method suitable for the liquid crystal display panel is also provided.

Description

Liquid crystal display panel and pixel driving method thereof

technical field

The present invention relates to a display panel and a pixel driving method thereof, and in particular to a liquid crystal display panel and a pixel driving method thereof.

Background technique

Generally speaking, a liquid crystal display panel is composed of two oppositely disposed substrates that sandwich a layer of liquid crystal molecules. The liquid crystal molecules have the characteristic of birefringence, and have different arrangement modes under different electric fields. Therefore, the liquid crystal display uses a common electric field to turn the liquid crystal molecules in the liquid crystal display panel, and then changes the arrangement of the liquid crystal molecules, so that each pixel on the liquid crystal display panel has different light transmittance, so as to achieve the purpose of imaging.

When the applied electric field is turned off, the time required for the long axis of the liquid crystal molecules to return to the original state without the electric field from the rotation state when there is an electric field is called relaxation time (relaxation time). As far as the nematic liquid crystal molecules are concerned, the relaxation time is much longer than the addressing time. The reason is that there is no external electric field to promote the liquid crystal molecules to return to their original state when they relax naturally. This effect will have a profound impact on field sequential color LCDs. For example, this effect will limit the frame rate of the field color sequential LCD and cause color breakup.

Therefore, it is necessary to provide a pixel driving method that can shorten the relaxation time of liquid crystal molecules and increase their response speed.

Contents of the invention

The invention provides a pixel driving method, which can effectively shorten the relaxation time of liquid crystal molecules and improve the response speed of the liquid crystal display panel.

The present invention provides a liquid crystal display panel, which can effectively shorten the relaxation time of liquid crystal molecules and increase the reaction speed by using the above-mentioned pixel driving method.

The invention provides a liquid crystal display panel, which has a plurality of pixels arranged in an array, and includes a substrate, a pair of opposite substrates and a liquid crystal layer. The substrate has a common electrode. The opposite substrate is disposed opposite to the substrate and has a plurality of pixel electrodes corresponding to the pixels. The liquid crystal layer is disposed between the substrate and the opposite substrate, and has a plurality of liquid crystal molecules. When the liquid crystal molecules are in transition, the pixel electrode is applied with at least two voltages of different levels, and the common electrode is applied with a common voltage of a specific level, and the common voltage of a specific level is between the two types of pixel electrodes. between voltages of different levels.

In an embodiment of the present invention, when the liquid crystal molecules are in transition, the pixel electrodes of the same row of pixels are given the same level of voltage.

In one embodiment of the present invention, when the liquid crystal molecules are in transition, the pixel electrodes of one of the two adjacent rows of pixels are given one of at least two different level voltages; The pixel electrode is supplied with the other one of at least two voltages of different levels.

The present invention provides a pixel driving method for driving the above-mentioned liquid crystal display panel. The pixel driving method includes the following steps: when a plurality of liquid crystal molecules in the liquid crystal layer are in transition, applying voltages of at least two different levels to a plurality of pixel electrodes on the opposite substrate; The common electrode of the device applies a common voltage of a specific level. Wherein, the common voltage of a certain level is between the voltages of two different levels of the pixel electrode.

In an embodiment of the present invention, the step of applying at least two voltages of different levels to the pixel electrodes includes: applying voltages of the same level to the pixel electrodes of the same row of pixels when the liquid crystal molecules transition.

In an embodiment of the present invention, the above-mentioned step of applying a common voltage of a specific level to the common electrode includes: when the liquid crystal molecules transition, one of at least two different level voltages is applied to two adjacent electrodes. The pixel electrodes of the rows of pixels are one row of pixel electrodes; and the other one of at least two different level voltages is applied to the pixel electrodes of another row of them.

In an embodiment of the present invention, the above-mentioned common voltage of a specific level is half of the absolute value of the sum of at least two voltages of different levels.

In an embodiment of the present invention, the cell gap of the above-mentioned liquid crystal layer is d, and the pixel size of the pixel electrode is p, wherein d and p satisfy p<4d.

In an embodiment of the present invention, the duration of the above-mentioned at least two voltages of different levels applied to the pixel electrode, and the duration of the application of the common voltage of a specific level to the common electrode are determined by at least one of the following factors : Voltages of at least two different levels, a common voltage of a specific level, a cell gap of a liquid crystal layer, and a pixel size of a pixel electrode.

Based on the above, in an exemplary embodiment of the present invention, the pixel driving method applies voltages of different levels to the pixel electrodes of the liquid crystal display panel when the liquid crystal molecules are in transition, so that a marginal electric field is generated between adjacent pixels, thereby improving the liquid crystal display. The response speed of the panel.

In order to make the above-mentioned features and advantages of the present invention more comprehensible, the following specific embodiments are described in detail with reference to the accompanying drawings.

Description of drawings

FIG. 1 is a schematic top view of a liquid crystal display panel according to an embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view of a liquid crystal display panel according to an embodiment of the present invention.

FIG. 3 is a schematic diagram illustrating the light transmittance of liquid crystal molecules changing with time according to an embodiment of the present invention.

FIG. 4 is a schematic cross-sectional view of the liquid crystal display panel of the embodiment shown in FIG. 2 , where the pixel electrodes and the common voltage are applied with specific voltages.

FIG. 5 is a flow chart showing the steps of a pixel driving method according to an embodiment of the present invention.

[Description of main component symbols]

100: LCD display panel

110: Substrate

112: common electrode

120: opposite substrate

122, 122_i-1, 122_i, 122_i+1: pixel electrodes

130: liquid crystal layer

d: The cell gap of the liquid crystal layer is

p: pixel size of the pixel electrode

P: pixel

P_0, P_1, P_i-1, P_i, P_i+1, P_N-1, P_N: pixel row

LC: liquid crystal molecules

S500, S510: steps of pixel driving method

Vcom, Vcom’: common voltage

Vp, Vp1, Vp2: pixel voltage

tr: transition period

tw, tb: period

E: marginal electric field

detailed description

In an exemplary embodiment of the present invention, the pixel driving method rapidly resets the liquid crystal molecules within sub-milliseconds, which utilizes the marginal electric field generated between adjacent pixels to accelerate the relaxation process of the liquid crystal molecules , so as to increase the response speed of the liquid crystal display panel. Accordingly, the frame rate of the liquid crystal display can be increased, thereby improving the color breakup. It should be noted, however, that the present invention is not limited to applications in field color sequential liquid crystal displays.

FIG. 1 is a schematic top view of a liquid crystal display panel according to an embodiment of the present invention. FIG. 2 is a schematic cross-sectional view of a liquid crystal display panel according to an embodiment of the present invention. Please refer to FIG. 1 and FIG. 2 , the liquid crystal display panel 100 of this embodiment has a plurality of pixels P arranged in an array. The liquid crystal display panel 100 includes a substrate 110 , an opposite substrate 120 and a liquid crystal layer 130 . The substrate 110 has at least one common electrode 112 disposed thereon. The opposite substrate 120 is disposed opposite to the substrate 110 and has a plurality of pixel electrodes 122 corresponding to the pixels P. As shown in FIG. The pixel size of each pixel electrode is p. The liquid crystal layer 130 is disposed on the substrate 110 and the opposite substrate 120 and has a plurality of liquid crystal molecules LC. The cell gap of the liquid crystal layer is d.

FIG. 3 is a schematic diagram illustrating the light transmittance of liquid crystal molecules changing with time according to an embodiment of the present invention. Please refer to FIG. 1 to FIG. 3 , in this embodiment, the liquid crystal display panel 100 is, for example, a twisted nematic mode (TN mode) liquid crystal display panel, which usually operates in a normally white mode (normally white mode). Therefore, during the period tb, when the common voltage Vcom and the corresponding pixel voltage Vp are respectively applied to the common electrode 112 and the pixel electrode 122, the liquid crystal molecules LC will be twisted, and the long axis direction of some liquid crystal molecules LC will be substantially perpendicular to the substrate. 110 and the opposite substrate 120 . At this time, the light source cannot pass through the liquid crystal molecules LC, and its light transmission rate approaches 0%.

Next, during the period tw, when the corresponding pixel voltage Vp is removed from the pixel electrode 122, it means that the liquid crystal molecules LC return from the rotation state when there is an electric field to the original state when there is no electric field. The reaction time effect is quite significant. Therefore, in order to accelerate the relaxation of the liquid crystal molecules LC and increase its response time, in this embodiment, when the liquid crystal molecules LC transition (for example, during the tr period), the pixel electrodes 122 in two adjacent rows are respectively given two different levels. The voltage Vp1 and Vp2. The common electrode 112 is supplied with a common voltage Vcom' of a certain level, and its level is between the voltages Vp1 and Vp2.

In detail, FIG. 4 shows a schematic cross-sectional view of the liquid crystal display panel of the embodiment shown in FIG. 2 , where the pixel electrodes and the common voltage are applied with specific voltages. Please refer to FIG. 4 , taking the pixel rows P_i-1, P_i and P_i+1 as an example, during the transition period tr of liquid crystal molecules LC, the pixel electrodes of the same row of pixels are applied with the same level of voltage. For example, the pixel electrode 122_i-1 of the pixel row P_i-1 and the pixel electrode 122_i+1 of the pixel row P_i+1 are given the same level of voltage Vp1; and the pixel electrode 122_i of the pixel row P_i is given the same level of voltage Vp1 Voltage Vp2. That is to say, during the liquid crystal molecules LC transition period tr, the pixel electrodes 122_i and 122_i+1 of two adjacent rows of pixels are applied to one of the two different level voltages Vp1 and Vp2; The other row of pixel electrodes 122_i+1 is supplied with the other of the two voltages Vp1 and Vp2 at different levels.

At this time, since the pixel electrodes in two adjacent rows have a voltage difference |Vp1-Vp2|, it can establish a marginal electric field E indicated by the arrow in Figure 4 in the liquid crystal layer 130, and its lateral component can accelerate the liquid crystal molecules LC. Relaxation makes it return to the original state without any external electric field, thereby effectively increasing the reaction time. In this embodiment, the level of the voltage Vp1 is greater than the voltage Vp2 to generate a marginal electric field E. In practical applications, the voltage Vp1 is, for example, 5 volts (V), and the voltage Vp2 is, for example, 0V, but the present invention is not limited thereto.

On the other hand, in this embodiment, the time length tr during which the voltages Vp1 and Vp2 are applied to the pixel electrode 122 and the common voltage Vcom' is applied to the common electrode 110 is determined by the levels of the voltages Vp1 and Vp2, the level of the common voltage Vcom', The cell gap d of the liquid crystal layer and the pixel size p of the pixel electrode are determined by at least one of them. Here, the duration of tr is, for example, about 0.5 milliseconds, that is, the liquid crystal molecules of the liquid crystal display panel 100 in this embodiment are quickly reset within a sub-milliseconds time interval. In addition, in this embodiment, because the common voltage Vcom' is too large or too small and the pixel size p of the pixel electrode is too large, the fringe electric field E will be attenuated, and the effect of accelerating the rotation of the liquid crystal molecules will be weakened. Therefore, in this embodiment, the common voltage Vcom' applied to the common electrode 110 is set to be half of the absolute value of the sum of the voltages Vp1 and Vp2, that is, Vcom'=|Vp1+Vp2|/2. Moreover, the pixel size p of the pixel electrode is less than four times the cell gap d of the liquid crystal layer, that is, d and p satisfy the condition of p<4d. In this case, it can be ensured that the marginal electric field E can effectively accelerate the transition of the liquid crystal molecules LC, thereby increasing the response speed of the liquid crystal display panel 100 .

FIG. 5 is a flow chart showing the steps of a pixel driving method according to an embodiment of the present invention. Please refer to FIG. 4 and FIG. 5 , the pixel driving method of this embodiment is suitable for driving the liquid crystal display panel 100 in FIG. 4 , and includes the following steps. In step S500 , at least two voltages Vp1 and Vp2 of different levels are applied to the plurality of pixel electrodes 122 of the counter substrate 120 when the liquid crystal molecules LC are in transition. Next, in step S510, when the liquid crystal molecules LC transition, a common voltage Vcom' of a specific level is applied to the common electrode 112 of the substrate 110. Wherein, the level of the common voltage Vcom' is between the voltages Vp1 and Vp2 of the pixel electrodes.

It should be noted that although this embodiment uses two steps to describe the pixel driving method of this embodiment, in order to achieve the purpose of generating the marginal electric field E, in practice, steps S500 and S510 can be performed at the same time, and there is no sequential relationship between them . That is, when the liquid crystal molecules transition, the voltages Vp1 and Vp2 and the common voltage Vcom' are applied to the pixel electrode 122 and the common electrode 112 respectively at the same time.

In addition, the pixel driving method of the embodiment of the present invention can obtain sufficient teachings, suggestions and implementation descriptions from the description of the embodiment in FIG. 1 to FIG. 4 , so no further description is given.

To sum up, in the exemplary embodiment of the present invention, the pixel driving method applies voltages of different levels to adjacent pixel electrodes, and the pixel electrodes in the same row have the same voltage level. Therefore, the adjacent pixel electrodes between the rows generate fringe electric fields in the liquid crystal layer, which can shorten the relaxation time of the liquid crystal molecules, thereby effectively accelerating the liquid crystal reaction speed and improving the display quality of the liquid crystal display panel.

Although the present invention has been disclosed as above with the embodiments, it is not intended to limit the present invention. Those skilled in the art can make some changes and modifications without departing from the spirit and scope of the present invention, so the protection scope of the present invention When depending on what is defined in the appended claims shall prevail.

Claims (12)

1. a display panels, has multiple pixel, arranges in an array mode, and this display panels comprises:

One first substrate, has a common electrode;

One second substrate, is configured at this first substrate subtend, has multiple pixel electrode and corresponds to these pixels; And

One liquid crystal layer, is configured between this first substrate and this second substrate, has multiple liquid crystal molecule,

Wherein when these liquid crystal molecule transitions, these pixel electrodes are imparted to the voltage of few two kinds of varying levels, and this common electrode is bestowed the common voltage of a particular level, and the common voltage of this particular level is between the voltage of these at least two kinds of varying levels;

Wherein liquid crystal molecule transition is that liquid crystal molecule is got back to without virgin state during electric field by rotation status when having electric field.

2. display panels as claimed in claim 1, wherein when these liquid crystal molecule transitions, these pixel electrodes with one-row pixels are bestowed the voltage of same level.

3. display panels as claimed in claim 2, wherein when these liquid crystal molecule transitions, the pixel electrode of these one of them row of pixel electrode of adjacent rows pixel is bestowed one of them of this at least two kinds of varying level voltages; The pixel electrode of another row is wherein bestowed wherein another of these at least two kinds of varying level voltages.

4. display panels as claimed in claim 3, wherein the common voltage of this particular level be the voltage of these at least two kinds of varying levels and the half of absolute value.

5. display panels as claimed in claim 1, wherein the cell gap of this liquid crystal layer is d, and the Pixel Dimensions of these pixel electrodes is p, and wherein d, p meet p<4d.

6. display panels as claimed in claim 1, wherein the voltage of these at least two kinds of varying levels bestows the time length of these pixel electrodes, and the time length that the common voltage of this particular level bestows this common electrode is decided by following at least one of them factor: the voltage of these at least two kinds of varying levels, the common voltage of this particular level, the cell gap of this liquid crystal layer and the Pixel Dimensions of these pixel electrodes.

7. an image element driving method, in order to drive a display panels, this display panels has multiple pixel, arranges in an array mode, and this display panels comprises a first substrate, a second substrate and a liquid crystal layer, and this image element driving method comprises:

When multiple liquid crystal molecule transition of this liquid crystal layer, bestow the multiple pixel electrodes of voltage in this second substrate of at least two kinds of varying levels; And

When these liquid crystal molecule transitions, bestow the common electrode of common voltage in this first substrate of a particular level,

Wherein the common voltage of this particular level is between the voltage of these at least two kinds of varying levels;

Wherein liquid crystal molecule transition is that liquid crystal molecule is got back to without virgin state during electric field by rotation status when having electric field.

8. image element driving method as claimed in claim 7, the voltage wherein bestowing these at least two kinds of varying levels comprises in the step of these pixel electrodes:

When these liquid crystal molecule transitions, bestow voltage these pixel electrodes in same one-row pixels of same level.

9. image element driving method as claimed in claim 8, the common voltage wherein bestowing this particular level comprises in the step of this common electrode:

When these liquid crystal molecule transitions, one of them bestowing these at least two kinds of varying level voltages is in the pixel electrode of these one of them row of pixel electrode of adjacent rows pixel; And

Bestow wherein another of these at least two kinds of varying level voltages in the pixel electrode of another row wherein.

10. image element driving method as claimed in claim 9, wherein the common voltage of this particular level be the voltage of these at least two kinds of varying levels and the half of absolute value.

11. image element driving methods as claimed in claim 7, wherein the cell gap of this liquid crystal layer is d, and the Pixel Dimensions of these pixel electrodes is p, and wherein d, p meet p<4d.

12. image element driving methods as claimed in claim 7, wherein the voltage of these at least two kinds of varying levels bestows the time length of these pixel electrodes, and the time length that the common voltage of this particular level bestows this common electrode is decided by following at least one of them factor: the voltage of these at least two kinds of varying levels, the common voltage of this particular level, the cell gap of this liquid crystal layer and the Pixel Dimensions of these pixel electrodes.