CN105137676B - A kind of pixel unit, array base palte and vertical alignment liquid crystal display device - Google Patents

Abstract

The embodiments of the present invention relate to the field of display technology, and in particular to a pixel unit, an array substrate, and a vertically aligned liquid crystal display device, which can reduce the number of fine and dark lines while increasing the deflection rate of liquid crystals. A pixel unit provided by an embodiment of the present invention includes: a first pixel electrode, the first pixel electrode includes strip-shaped electrode groups connected to each other in at least two directions, and electrodes in each strip-shaped electrode group There is a slit between them; the second pixel electrode located below the first pixel electrode, the second pixel electrode at least overlaps the area where the slit of the first pixel electrode is located; the first thin film transistor, the second thin film transistor and third thin film transistor. It is used in the preparation of pixel units, array substrates and vertical alignment liquid crystal display devices.

Description

A pixel unit, an array substrate and a vertical alignment type liquid crystal display device

technical field

The invention relates to the field of display technology, in particular to a pixel unit, an array substrate and a vertical alignment type liquid crystal display device.

Background technique

Polymer Stabilization Vertical Alignment (PSVA for short) technology is to generate a polymer layer on the alignment film that can make the VA liquid crystal form a pre-tilt angle. Wherein, the formation process of the polymer layer is shown in Fig. 1a to Fig. 1c. As shown in Figure 1a, before the voltage is applied to the upper and lower substrates, the directors of ordinary liquid crystal molecules are aligned perpendicular to the upper and lower substrates. Before the voltage is applied, a certain proportion of high-purity reactive liquid crystal (English: Reactive Mesogen) is mixed into the ordinary VA liquid crystal. The reactive liquid crystal has a liquid crystal nucleus of ordinary liquid crystal molecules and one or more acrylics at the end. Reactive functional groups such as Acrylate Group (English: Acrylate Group). The reactive functional group is polymerized into a polymer network after being irradiated with ultraviolet light (Ultra Violet, referred to as UV), which can achieve permanent fixation.

As shown in Figure 1b, before the UV light is irradiated, a voltage is applied on the upper and lower substrates to make the liquid crystal molecules generate a pre-tilt angle, wherein the liquid crystal molecules in different domains in the pixel unit have different tilt directions (Figure 1b The tilt direction of the liquid crystal molecules in different domains is not shown); when the liquid crystal has a tilt angle due to the applied external voltage, UV irradiation can be carried out, because the reactive liquid crystal is mixed in the ordinary liquid crystal, and the reactive liquid crystal is subjected to UV After irradiation, it can be polymerized into a polymer network to achieve permanent fixation, so that the liquid crystal molecules close to the upper and lower substrates can form a fixed pretilt angle. As shown in Figure 1c, after the UV irradiation is over, the applied voltage is removed. Since the liquid crystal molecules close to the upper and lower substrates are affected by the polymer network, a fixed pre-tilt angle is formed, while the liquid crystal molecules in the middle layer are not affected by the polymer network molecules, and return to the arrangement perpendicular to the upper and lower substrates.

FIG. 2 exemplarily shows a schematic plan view of a pixel electrode in a multi-domain vertical alignment type liquid crystal display device in the prior art. As shown in Figure 2, in order to achieve vertical alignment multi-domain display, the pixel electrode pattern (English: pixelpattern) is usually made into a pixel electrode with a slit (English: pixel slit), so that the liquid crystal is in the pixel electrode and Under the action of the common electrode on the color filter substrate, it can be tilted in multiple directions to form multi-domain alignment of liquid crystal. Since there is a gap between the electrode stripes of the pixel electrode, the electric field strength formed between the gap between the electrode stripes and the common electrode will be weaker than the electric field strength formed between the electrode stripes and the common electrode, so the distance between the electrode stripes and the common electrode The force generated by the electric field formed between the electrode stripes on the liquid crystal molecules will be greater than the force generated by the electric field formed between the electrode stripes and the common electrode on the liquid crystal molecules, resulting in a relatively low deflection efficiency of the liquid crystal. Dark streaks are formed.

In order to solve the above-mentioned problem of dark stripes, the pixel electrode manufacturing process is used in the industry to reduce the gap between the electrode stripes of the pixel electrodes, which can reduce the width of the dark stripes. With the above method, although the width of the dark stripes can be reduced, the dark stripes still cannot be reduced.

Contents of the invention

Embodiments of the present invention provide a pixel unit, an array substrate, and a vertical alignment type liquid crystal display device, which can reduce the number of dark stripes while increasing the liquid crystal deflection rate.

An embodiment of the present invention provides a pixel unit, including:

A first pixel electrode, the first pixel electrode includes strip-shaped electrode groups connected to each other in at least two directions, and there are slits between electrodes in each of the strip-shaped electrode groups;

a second pixel electrode located below the first pixel electrode, the second pixel electrode at least overlaps the area where the slit of the first pixel electrode is located;

The first thin film transistor is used to transmit a data line signal to the first pixel electrode;

the second thin film transistor is used to transmit the data line signal to the second pixel electrode;

The third thin film transistor is used to transmit the data line signal of the first pixel electrode or the second pixel electrode to the voltage dividing electrode.

Preferably, the gate, source, and drain of the first thin film transistor are electrically connected to the first scan line, the data line, and the first pixel electrode, respectively;

The gate, source, and drain of the second thin film transistor are respectively electrically connected to the first scan line, the data line, and the second pixel electrode, wherein the data line is used to transmit data line signals ;

The gate, source, and drain of the third thin film transistor are electrically connected to the second scan line, the first pixel electrode or the second pixel electrode, and the voltage dividing electrode, respectively.

Preferably, the first pixel electrode has a "rice" structure, including: two first strip-shaped electrode groups arranged in a "丷" character, and two second strip-shaped electrode groups arranged in a "eight" character An electrode group, and inter-domain electrodes in the shape of a "cross" connected to each strip-shaped electrode group.

Preferably, the angles between the electrodes in the two first strip-shaped electrode groups and the lateral electrodes in the inter-domain electrodes are between 35° and 55°; the second strip-shaped electrode group on the left side The angle between the electrodes in the electrode and the lateral electrodes in the inter-domain electrodes is between 35°-55°; the angle between the electrodes in the second strip-shaped electrode group on the right and the lateral electrodes in the inter-domain electrodes The included angle is between 35° and 65°.

Preferably, the pitch of the slits is 3-20 microns.

Preferably, the second pixel electrode includes strip-shaped electrode groups connected to each other in at least two directions, and there are slits between electrodes in each strip-shaped electrode group.

Preferably, the second pixel electrode is a planar electrode.

Preferably, the source of the first thin film transistor is connected to the data line, and the source of the second thin film transistor is connected to the source of the first thin film transistor.

Preferably, the source of the third thin film transistor is a part of the drain of the second thin film transistor.

Preferably, the overlapping region of the voltage dividing electrode and the first pixel electrode forms a first storage capacitor;

The overlapping region of the voltage dividing electrode and the second pixel electrode forms a second storage capacitor.

An embodiment of the present invention also provides an array substrate, including:

The first scanning line and the second scanning line arranged in pairs;

a data line intersecting the first scan line and the second scan line;

A pixel unit connected to the first scan line, the second scan line and the data line is the pixel unit in the above embodiment.

An embodiment of the present invention also provides a vertical alignment type liquid crystal display device, comprising:

The array substrate in the above embodiments;

A color filter substrate, the color filter substrate is arranged opposite to the array substrate, and a common electrode is arranged on the color filter substrate;

The liquid crystal layer is arranged between the array substrate and the color filter substrate.

In the embodiment of the present invention, the provided first pixel electrode includes strip-shaped electrode groups connected to each other in at least two directions, each of the strip-shaped electrode groups has a slit between electrodes; The second pixel electrode below, the second pixel electrode at least overlaps the area where the slit of the first pixel electrode is located; the first thin film transistor is used to transmit the data line signal to the first pixel electrode; the second thin film transistor used to transmit the data line signal to the second pixel electrode; the third thin film transistor is used to transmit the data line signal of the first pixel electrode or the second pixel electrode to the voltage dividing electrode; in the pixel structure In this case, the second pixel electrode overlaps the strip-shaped electrode interval area of the first pixel electrode, when the electric field formed between the strip-shaped electrode of the first pixel electrode and the common electrode arranged on the color filter substrate is greater than the strip-shaped electrode interval area and When the electric field formed between the common electrodes on the color filter substrate is set, since the second pixel electrode overlaps the strip-shaped electrode spacing area of the first pixel electrode, the second pixel electrode can be connected to the common electrode on the color filter substrate. An electric field is also formed between them. That is, the liquid crystal located in the interval area of the first pixel electrode and the strip-shaped electrode is subjected to the force of the electric field formed between the second pixel electrode and the common electrode arranged on the color filter substrate, and can generate sufficient deflection, thereby increasing the deflection rate of the liquid crystal. At the same time, the number of dark stripes generated in the first pixel electrode strip-shaped electrode spacing area is reduced.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. Those skilled in the art can also obtain other drawings based on these drawings without creative work.

Figure 1a is a schematic diagram of the arrangement of ordinary liquid crystal molecules in the upper and lower substrates in the prior art;

Figure 1b is a schematic diagram of the arrangement of liquid crystal molecules on the upper and lower substrates after voltage is applied to the upper and lower substrates in the prior art;

Figure 1c is a schematic diagram of the arrangement of liquid crystal molecules on the upper and lower substrates after UV irradiation in the prior art;

2 is a schematic plan view of a multi-domain vertically aligned pixel unit in the prior art;

FIG. 3 is a schematic structural diagram of a pixel unit provided by an embodiment of the present invention;

Fig. 4a is a schematic diagram of a distribution of a first pixel electrode in a pixel unit according to an embodiment of the present invention;

Fig. 4b is a schematic diagram of another distribution of the first pixel electrode in the pixel unit provided by the embodiment of the present invention;

Fig. 5a is a schematic structural diagram of a pixel unit in which the first pixel electrode is a "rice" structure provided by an embodiment of the present invention;

Fig. 5b is a schematic structural diagram of a pixel unit including a first pixel electrode and a second pixel electrode provided by an embodiment of the present invention;

Fig. 5c is a schematic vertical cross-sectional view of a first pixel electrode and a second pixel electrode provided by an embodiment of the present invention;

FIG. 5d is a schematic structural diagram of another pixel unit including a first pixel electrode and a second pixel electrode provided by an embodiment of the present invention;

FIG. 5e is a schematic vertical cross-sectional view of another first pixel electrode and a second pixel electrode provided by an embodiment of the present invention;

FIG. 6 is a schematic structural diagram of an array substrate provided by an embodiment of the present invention;

FIG. 7 is a schematic structural diagram of a liquid crystal display provided by an embodiment of the present invention.

Detailed ways

The preferred embodiments of the present invention will be described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described here are only used to illustrate and explain the present invention, and are not intended to limit the present invention, and in the absence of conflict, the present invention The embodiments and the features in the embodiments can be combined with each other.

An embodiment of the present invention provides a pixel unit, which is usually arranged on an array substrate of a display device, as shown in FIG. Two thin film transistors 304 and a third thin film transistor 305; wherein, the first pixel electrode 301 includes strip-shaped electrode groups connected to each other in at least two directions, and there is a slit m between electrodes in each strip-shaped electrode group; The second pixel electrode 302 is located below the first pixel electrode 301 , and the second pixel electrode 302 partially or completely overlaps the area where the slit m of the strip-shaped electrode group of the first pixel electrode 301 is located.

As shown in FIG. 3 , the pixel unit further includes a first scanning line 306 , a data line 307 , a second scanning line 308 and a voltage dividing electrode 309 . Specifically, the first thin film transistor 303 is used to transmit the data line signal to the first pixel electrode 301, the second thin film transistor 304 is used to transmit the data line signal to the second pixel electrode 302, and the third thin film transistor 305 is used to transmit the data line signal to the second pixel electrode 302. Used to transmit the data line signal of the first pixel electrode 301 to the voltage dividing electrode 309 .

It should be noted that, in the above embodiment, the third thin film transistor 305 is also used to transmit the data line signal of the second pixel electrode 302 to the voltage dividing electrode 309 . In the embodiment of the present invention, there is no specific limitation on whether the third thin film transistor transmits the data line signal of the first pixel electrode or the data line signal of the second pixel electrode to the voltage dividing electrode.

As shown in Figure 3, the gate of the first thin film transistor 303 is electrically connected to the first scanning line 306, the source of the first thin film transistor 303 is electrically connected to the data line 307, and the drain of the first thin film transistor 303 is electrically connected to the first pixel The electrode 301 is electrically connected; the gate of the second thin film transistor 304 is electrically connected to the first scan line 306, the source of the second thin film transistor 304 is electrically connected to the data line 307, and the drain of the second thin film transistor is connected to the second pixel electrode 302 Electrical connection; the gate of the third thin film transistor 305 is electrically connected to the second scanning line 308, the source of the third thin film transistor 305 is electrically connected to the second pixel electrode 302, and the drain of the third thin film transistor 305 is electrically connected to the voltage dividing electrode 309 electrical connection.

It should be noted that when the gate of the first thin film transistor 303 is electrically connected to the first scanning line 306, the source of the first thin film transistor 303 is electrically connected to the data line 307, and the drain of the first thin film transistor 303 is electrically connected to the first pixel When the electrode 301 is electrically connected, the data line 307 transmits the data line signal for the first pixel electrode 301; Electrically connected, when the drain of the second thin film transistor is electrically connected to the second pixel electrode 302, the data line 307 transmits the data line signal for the second pixel electrode.

In the above embodiments, it should be noted that the source of the third thin film transistor 305 may also be electrically connected to the first pixel electrode 301 instead of electrically connected to the second pixel electrode 302 .

In practical applications, electrical connection (English: electrically coupled to) includes direct or indirect connection, and includes inductive coupling; electrical connection (English: electrically connected to) usually refers to direct connection, excluding inductive coupling. kind.

In the embodiment of the present invention, the pixel electrode electrically connected to the source of the third thin film transistor is not specifically limited, and at the same time, the connection method of the pixel electrode connected to the source of the third thin film transistor is not specifically shown.

Here, in order to meet the requirement that the electric field formed between the electrodes in the first pixel electrode electrode group and the common electrode provided on the color filter substrate can provide equal force for the liquid crystal in the liquid crystal layer, preferably, the same strip electrode group can be The slit m between the electrodes in the set is the same width, and the width of each electrode in the same strip electrode group can also be set to the same width; it is also possible to set the slit m between the electrodes in the same strip electrode group m is set to be the same width, and at the same time, the widths of multiple electrodes in the same strip-shaped electrode group are set to be the same width. In the embodiment of the present invention, the width of the slit between the electrodes in the same strip-shaped electrode group and the width of the electrodes in the same strip-shaped electrode group are not specifically limited.

In the embodiment of the present invention, the strip-shaped electrode group includes a plurality of mutually parallel electrodes with gaps between the electrodes, that is, one strip-shaped electrode group has a group of electrodes arranged in the same direction.

In the embodiment of the present invention, for the convenience of description, the upper electrode among the pixel electrodes is called the first pixel electrode, and the lower electrode among the pixel electrodes is called the second pixel electrode. The strip-shaped electrode groups connected to each other in at least two directions included in the first pixel electrode, wherein the distribution of the strip-shaped electrode groups in the pixel unit is not limited to the distribution shown in FIG. 3 , in the embodiment of the present invention, the first A pixel electrode only needs to meet the following conditions:

(1) Strip-shaped electrode groups having at least two directions;

(2) the above-mentioned strip electrode groups are connected to each other;

(3) The electrodes in each strip-shaped electrode group have slits.

Fig. 4a exemplarily shows a distribution situation of the first pixel electrodes in the pixel units. As shown in FIG. 4a, the first pixel electrode 401a includes a strip-shaped electrode group connected to each other with two directions, and there are slits between electrodes in the strip-shaped electrode group. The first pixel electrode 401a is located above the pixel electrode, and the second pixel electrode 402a is located below the pixel electrode (not shown in the figure), wherein the strip-shaped electrode groups are connected to each other. In the embodiment of the present invention, the strip-shaped electrodes The connection point between the groups can be located above the strip electrode group, can be located below the strip electrode group, or can be located in the middle of the strip electrode group. Specific limits.

Further, if the first pixel electrode 401a in FIG. 4a is rotated in the pixel unit, the first pixel electrode 402a shown in FIG. 4b can be obtained, the first pixel electrode 402a shown in FIG. The structure of the first pixel electrode 401a shown in FIG. 1 is the same, having strip-shaped electrode groups connected to each other in two directions, and having slits between electrodes in the strip-shaped electrode group, and located above the pixel electrodes; FIG. 4b The second pixel electrode 402b (not shown in the figure) is located below the pixel electrode. Moreover, the first pixel electrodes 402a in FIG. 4b are also connected to each other, and the connection method is the same as that in FIG. 4a , which will not be repeated here.

Further, if the first pixel electrode 401a in FIG. 4a is continuously rotated in the pixel electrode, the first pixel electrode in the direction opposite to the first pixel electrode 401a in FIG. 4a can be obtained; if the first pixel electrode in FIG. 4a The electrode 401a continues to rotate in the pixel electrode, and a first pixel electrode opposite to the direction of the first pixel electrode 402a in FIG. 4b can also be obtained. In the embodiment of the present invention, there is no specific limitation on the orientation of the electrode group having two directions and interconnected first pixel electrodes, and having slits between electrodes in the strip-shaped electrode group.

In an embodiment of the present invention, the first pixel electrode includes strip-shaped electrode groups connected to each other in at least two directions, and there are slits between electrodes in each strip-shaped electrode group; the second pixel electrode is located below the first pixel electrode , and the second pixel electrode at least overlaps the area where the slit of the first pixel electrode is located; the gate, source, and drain of the first thin film transistor are respectively electrically connected to the first scanning line, the data line and the first pixel electrode; The gate, source, and drain of the second thin film transistor are electrically connected to the first scan line, the data line, and the second pixel electrode respectively; the gate, source, and drain of the third thin film are respectively connected to the second scan line, the first The pixel electrode or the second pixel electrode is electrically connected to the voltage dividing electrode. When the first thin film transistor and the second thin film transistor are turned on, the data line will charge the first pixel electrode and the second pixel electrode at the same time, and after the charging of the first pixel electrode and the second pixel electrode is completed, the first scan line will show a low voltage state, turn off the first thin film transistor and the second thin film transistor; the second scanning line is in a high voltage state, and the third thin film transistor will be turned on, because the gate, source, and drain of the third thin film transistor are respectively connected to the second scanning line , the second pixel electrode or the first pixel electrode, and the voltage dividing electrode are electrically connected. For example, the second pixel electrode is electrically connected to the source of the third thin film transistor. When the third thin film transistor is turned on, the charge stored in the second pixel electrode will charge the voltage dividing electrode, or the voltage dividing electrode will charge the second pixel electrode. The second pixel electrode is charged, so the charge stored in the second pixel electrode will be different from the charge stored in the first pixel electrode.

When an electric field is formed between the electrodes in the strip-shaped electrode group of the first pixel electrode and the common electrode provided on the color filter substrate, the slits between the electrodes in the strip-shaped electrode group of the first pixel electrode will also An electric field is formed between the common electrodes on the color filter substrate. Since there is charge stored in the first pixel electrode, but no charge is stored in the slit area between the electrodes in the strip-shaped electrode group of the first pixel electrode, a gap is formed between the electrodes and the common electrode arranged on the color filter substrate. The electric field will be larger than the electric field formed between the slit area and the common electrode provided on the color filter substrate. That is, the force provided by the electric field formed between the slit area and the common electrode on the color filter substrate for the liquid crystal in the liquid crystal layer is smaller than the force provided by the electric field formed between the electrode and the common electrode on the color filter substrate for the liquid crystal layer. The force provided by the liquid crystal. At the same time, the deflection rate of the liquid crystal in the liquid crystal layer corresponding to the slit area will be relatively low.

In the embodiment of the present invention, the second pixel electrode is located below the first pixel electrode, and at least partly or completely overlaps the area where the slit of the first pixel electrode is located, because the charge stored in the first pixel electrode is different from that of the second pixel electrode. The charge stored in the pixel electrode, that is, the electric field formed between the strip electrode of the first pixel electrode and the common electrode arranged on the color filter substrate will also be different from that between the second pixel electrode and the common electrode arranged on the color filter substrate. Since the second pixel electrode at least partially or completely overlaps the slit area of the first pixel electrode, the electric field formed between the slit area of the first pixel electrode and the common electrode arranged on the color filter substrate When the electric field is relatively weak, an electric field can be formed between the second pixel electrode and the common electrode arranged on the color filter substrate, and the strength of the electric field will be greater than that between the slit area of the first pixel electrode and the common electrode arranged on the color filter substrate. The electric field strength formed between. Therefore, the electric field formed between the second pixel electrode and the common electrode arranged on the color filter substrate provides a greater force for the liquid crystal in the liquid crystal layer than the electric field formed between the slit region and the common electrode arranged on the color filter substrate is The force provided by the liquid crystal of the liquid crystal layer. By adopting the method provided by the embodiment of the present invention, the number of dark stripes formed in the strip-shaped electrode slit area of the first pixel electrode can be reduced while increasing the liquid crystal deflection rate.

Based on the same inventive concept, a pixel unit provided by an embodiment of the present invention will be described below with reference to FIG. 5a , FIG. 5b and FIG. 5c . Fig. 5a exemplarily shows a schematic structural diagram of a first pixel electrode provided by an embodiment of the present invention; Fig. 5b is a schematic structural diagram including a first pixel electrode and a second pixel electrode provided by an embodiment of the present invention; The vertical cross-sectional schematic diagram of the first pixel electrode and the second pixel electrode in FIG.

The embodiments of the present invention only further limit the specific shape of the first pixel electrode in the pixel unit, and for other structures of the pixel unit, reference may be made to the above-mentioned embodiments.

In the embodiment of the present invention, the distribution of the first pixel electrode in the pixel unit is shown in FIG. Two first strip-shaped electrode groups 501a-1 arranged, two second strip-shaped electrode groups 501a-2 arranged in the shape of "eight", and a "ten" character connected to each strip-shaped electrode group shaped inter-domain electrodes 501a-3.

It should be noted that the shapes of the electrodes in the first strip-shaped electrode group 501a-1 and the second strip-shaped electrode group 501a-2 included in the first pixel electrode may be completely the same, or may be partially the same. In the embodiment of the present invention, for Whether the shapes of the first strip-shaped electrode group 501a-1 and the second strip-shaped electrode group 501a-2 are the same is not specifically limited.

Specifically, the angle between the electrode on the left side of the first strip-shaped electrode group 501a-1 and the lateral electrode in the inter-domain electrode 501a-3 is a, wherein the angle a is between 35° and 55°; The included angle between the electrode on the right side of the first strip-shaped electrode group 501a-1 and the lateral electrode in the inter-domain electrode 501a-3 is b, wherein the included angle b is between 35° and 55°; The angle between the left electrode of the strip-shaped electrode group 501a-2 and the lateral electrode in the inter-domain electrode 501a-3 is d, wherein the angle d is between 35° and 55°; the second strip-shaped electrode group 501a The included angle between the right electrode of -2 and the lateral electrode in the inter-domain electrode 501a-3 is c, wherein the included angle c is between 35° and 65°.

In the embodiment of the present invention, there is no specific limitation on the angle between the electrodes in the first strip-shaped electrode group 501a-1 and the lateral electrodes in the inter-domain electrodes 501a-3, and the angle between the electrodes in the second strip-shaped electrode group 501a The angle between the electrodes in -2 and the lateral electrodes in the inter-domain electrodes 501a-3 is also not specifically limited.

Since there are slits between the electrodes in the strip-shaped electrode group included in the first pixel electrode, if the spacing between the slits in the first pixel electrode is relatively small, the electrodes in the strip-shaped electrode group in the first pixel electrode are arranged at and between The electric field formed between the common electrodes of the color filter substrate will interact with the electric field formed between the second pixel electrode overlapping or partially overlapping the slit area of the first pixel electrode and the common electrode arranged on the color filter substrate. interference.

In the embodiment of the present invention, in order to reduce the electric field formed between the electrode in the strip-shaped electrode group in the first pixel electrode and the common electrode provided on the color filter substrate, the area overlapping or partially overlapping the first pixel slit The electric field formed between the second pixel electrode and the common electrode arranged on the color filter substrate will interfere with each other. Preferably, the slit distance between the electrodes in the strip electrode group of the first pixel electrode is between 3 and Between 20 microns.

In the embodiment of the present invention, the second pixel electrode is located below the first pixel electrode, and the second pixel electrode at least partially or completely overlaps the area where the slit of the first pixel is located. The shape of the second pixel electrode provided in the embodiment of the present invention includes at least the following two situations:

In one embodiment, the second pixel electrode can be made into a shape similar to that of the first pixel electrode. For example, the second pixel electrode includes strip-shaped electrode groups connected to each other in at least two directions, and each strip-shaped electrode group There are slits between the electrodes. Since the second pixel electrode needs to overlap at least the area where the slit of the first pixel electrode is located, the electrodes in the strip-shaped electrode group of the second pixel electrode can be partially or completely located in the area where the slit of the first pixel electrode is located, and the second The slit between the electrodes in the strip-shaped electrode group of the pixel electrode is also located just below the strip-shaped electrode of the first pixel electrode.

As shown in FIG. 5b, the shape of the second pixel electrode 501b is similar to that of the first pixel electrode 501a. Since the slit width of the first pixel electrode is between 3 and 20 microns, in the embodiment of the present invention, the second The slit pitch of a pixel electrode 501a may be smaller than the electrode width of the second pixel electrode 501b; may be larger than the electrode width of the second pixel electrode 501b; or may be equal to the electrode width of the second pixel electrode 501b.

When the slit pitch of the first pixel electrode 501a is greater than the electrode width of the second pixel electrode 501b, the electrode of the second pixel electrode 501b can only partially overlap the area where the slit of the first pixel electrode is located, that is, the area of the first pixel electrode 501a. Part of the area where the slit is located is not occupied by the electrodes of the second pixel electrode; when the slit pitch of the first pixel electrode 501a is equal to the electrode width of the second pixel electrode 501b, the electrodes of the second pixel electrode 501b can all overlap The area where the slit of the first pixel electrode is located; when the slit pitch of the first pixel electrode 501a is smaller than the electrode width of the second pixel electrode 501b, the electrodes of the second pixel electrode 501b can not only completely overlap the slit of the first pixel electrode The region where it is located, and a part of the region will extend below the electrode of the first pixel electrode. In the embodiment of the present invention, there is no specific limitation on the size of the slit width of the first pixel electrode and the electrode width of the second pixel electrode.

5c is a schematic cross-sectional view of line AA in FIG. 5b. In FIG. There are four electrodes in the electrode group 501b, and the width of the region where the slit of the first pixel electrode 501a is located is equal to the electrode width of the second pixel electrode. As shown in Figure 5c, the electrode width of the electrode group of the second pixel electrode 501b is equal to the width of the area where the slit of the first pixel electrode 501a is located, that is, the second pixel electrode 501b completely overlaps the area where the slit of the first pixel electrode 501a is located. area, and the electrode of the second pixel electrode 501b does not extend below the electrode of the first pixel electrode 501a.

In the above embodiment, the electric field formed by the slit area of the first pixel electrode and the common electrode arranged on the color filter substrate is larger than the electric field formed by the electrodes in the electrode group of the first pixel electrode and the common electrode arranged on the color filter substrate. The electric field is weak, because the second pixel electrode is located below the first pixel electrode, and at least part of the second pixel electrode overlaps the area where the slit of the first pixel electrode is located, that is, the area where the slit is located is provided by the liquid crystal in the liquid crystal layer. When the deflection force is smaller than the deflection force provided by the liquid crystal in the liquid crystal layer in the area where the electrode is located, the electric field formed by the electrode in the electrode group of the second pixel electrode and the common electrode arranged on the color filter substrate will be the location of the slit. The liquid crystals in the liquid crystal layer corresponding to the regions provide deflection force. Therefore, when the second pixel electrode is located below the first pixel electrode, and at least part of the pixel electrode overlaps the area where the slit of the first pixel electrode is located, the deflection rate of the liquid crystal can be improved, and at the same time, the dark stripes in the prior art can be reduced. quantity.

In another embodiment, the second pixel electrode can be made into a planar structure. As shown in FIG. 5d, the second pixel electrode 502b is located below the first pixel electrode 502a. Since the second pixel electrode 502b is planar, the second pixel electrode 502b can completely overlap the first pixel electrode 502a. Fig. 5e is a schematic cross-sectional view of line BB in Fig. 5d. Since the second pixel electrode 502b has a planar structure, in Fig. 5e, the second pixel electrode 502b not only completely overlaps the region where the slit of the first pixel electrode 502a is located. , and completely overlaps below the area where the electrode of the first pixel electrode 502a is located.

When the electric field formed between the electrodes in the strip-shaped electrode group of the first pixel electrode and the common electrode arranged on the color filter substrate is larger than the electric field formed by the first pixel electrode and the common electrode arranged on the color filter substrate The electric field is weak, and the deflection force provided by the liquid crystal in the liquid crystal layer is relatively small. The electric field formed by the second pixel electrode located under the slit area of the first pixel electrode and the common electrode arranged on the color filter substrate can just be the liquid crystal. The layer of liquid crystal provides sufficient deflection force. Therefore, when the second pixel electrode is located below the first pixel electrode, and the second pixel electrode completely overlaps the area where the slit of the first pixel electrode is located, the deflection rate of the liquid crystal can be improved, and at the same time, the dark stripes in the prior art can be reduced. quantity.

The pixel unit in the embodiment of the present invention further includes a first thin film transistor, a second thin film transistor and a third thin film transistor. Here, the gate, source and drain of the first thin film transistor are electrically connected to the first scan line, the data line and the first pixel electrode respectively; the gate, source and drain of the second thin film transistor are respectively connected to the first The scan line, the data line and the second pixel electrode are electrically connected; preferably, as shown in FIG. The source of 304 is connected to the data line through the source of the first thin film transistor 303, thereby reducing the number of leads in the pixel unit and simplifying the manufacturing process of the pixel unit.

Optionally, the source of the second thin film transistor may also be directly electrically connected to the data line, and the source of the first thin film transistor is also directly electrically connected to the data line.

On this basis, there is no specific limitation on the connection method between the source electrode of the second thin film transistor and the data line in the embodiment of the present invention.

In the embodiment of the present invention, in order to control the grayscale of the display screen, the problem of color washout at large viewing angles is improved.

In one embodiment, by adjusting the relative area of the first pixel electrode and the second pixel electrode, the size of the electric field formed between the first pixel electrode and the common electrode provided on the color filter substrate can be changed, and the second pixel electrode can be changed. The magnitude of the electric field formed between the electrode and the common electrode set on the color filter substrate.

When the second pixel electrode is a planar structure, since the shape of the second pixel electrode is fixed, the distance between the first pixel electrode and the second pixel electrode can be changed by adjusting the electrode width in the strip electrode group of the first pixel electrode. Relative area ratio, by changing the relative area ratio between the first pixel electrode and the second pixel electrode, the electric field force formed between the first pixel electrode, the second pixel electrode and the common electrode arranged on the color filter substrate can be changed; When the shape of the second pixel electrode is the same as the shape of the first pixel electrode, the electrode width in the strip-shaped electrode group of the first pixel electrode can be adjusted to keep the shape of the second pixel electrode unchanged; the strip of the second pixel electrode can be adjusted. The electrode width in the strip-shaped electrode group keeps the shape of the first pixel electrode unchanged; the electrode width in the strip-shaped electrode group of the first pixel electrode and the electrode width in the strip-shaped electrode group of the second pixel electrode can also be adjusted simultaneously; Thereby changing the relative area ratio of the first pixel electrode and the second pixel electrode, changing the electric field force formed between the first pixel electrode and the second pixel electrode and the common electrode arranged on the color filter substrate; that is, further changing the liquid crystal layer The deflection force of the internal liquid crystal can be used to control the gray scale of the display screen and improve the problem of color washout at large viewing angles.

In another embodiment, since the source of the third thin film transistor is a part of the drain of the second thin film transistor, that is, a segment of the drain of the second thin film transistor is shared by the third thin film transistor as the source of the third thin film transistor . The drain of the third thin film transistor is electrically connected to the voltage-dividing electrode. In the embodiment of the present invention, since the voltage-dividing electrode is located at and below the edge region of the pixel electrode, it can be determined that the overlapping area of the voltage-dividing electrode and the first pixel electrode forms a The first storage capacitor, the overlapping region of the voltage dividing electrode and the second pixel electrode forms a second storage capacitor. When the area where the voltage-dividing electrode and the first pixel electrode overlap forms the first storage capacitor, the amount of charge in the first storage capacitor can be changed by adjusting the relative area between the first pixel electrode and the voltage-dividing electrode; When the overlapping region of the second pixel electrode and the second pixel electrode forms the second storage capacitor, the amount of charge in the second storage capacitor can be changed by adjusting the relative area between the second pixel electrode and the voltage-dividing electrode.

Because the gate, source, and drain of the third thin film transistor are electrically connected to the second scan line, the first pixel electrode or the second pixel electrode, and the voltage dividing electrode, respectively. If the source of the third thin film transistor is electrically connected to the second pixel electrode, since the second pixel electrode is in a high voltage state on the first scanning line, the charging of the second pixel electrode has been completed. Since the voltage-dividing electrode can form a first storage capacitor in an overlapping region with the first pixel electrode, and form a second storage capacitor in an overlapping region with the second pixel electrode. When the second scanning line is in a high voltage state, the third thin film transistor will be turned on, and if the amount of charge stored in the capacitor connected in series with the first storage capacitor and the second storage capacitor is less than the amount of charge in the second pixel electrode, the second pixel The electrode will charge the storage electrode, and after the charge stored in the storage capacitor of the voltage-dividing electrode is equal to the charge stored in the second pixel electrode, the second pixel electrode will stop charging the storage capacitor of the voltage-dividing electrode. If the amount of charge stored in the capacitor connected in series with the first storage capacitor and the second storage capacitor is greater than the amount of charge in the second pixel electrode, the storage electrode of the voltage-dividing electrode will charge the second pixel electrode, and the storage capacitor of the voltage-dividing electrode will be charged to the second pixel electrode. After the charge stored in the second pixel electrode is equal to the charge stored in the second pixel electrode, the storage capacitor of the voltage dividing electrode stops charging the second pixel electrode.

In the embodiment of the present invention, by changing the area of the overlapping area between the voltage dividing electrode and the first pixel electrode; or by changing the area of the overlapping area between the voltage dividing electrode and the second pixel electrode; The area of the overlapping region between the first pixel electrode and the second pixel electrode. To change the amount of charge in the storage capacitor of the voltage-dividing electrode. At the same time, after the third thin film transistor is turned on, if the third thin film transistor is electrically connected to the first pixel electrode, the amount of charge in the first pixel electrode can be changed; if the third thin film transistor is electrically connected to the second pixel electrode, it can be Change the amount of charge in the second pixel electrode. In this way, it is possible to control the grayscale of the display screen and improve the problem of color washout at large viewing angles.

In the above embodiment, the first pixel electrode and the second pixel electrode are transparent electrodes, and the transparent electrodes can be made of tin oxide (Indium Tin Oxide, ITO for short), indium zinc oxide (Indium Zinc Oxide, IZO for short), and aluminum At least one of transparent conductive oxide materials such as Aluminum Zinc Oxide (AZO for short). In the embodiment of the present invention, there is no specific limitation on the constituent materials of the first pixel electrode and the second pixel electrode.

As shown in FIG. 6 , an embodiment of the present invention provides an array substrate, including: first scanning lines 601 and second scanning lines 602 arranged in pairs; line 603; a pixel unit 604 connected to the first scanning line 601, the second scanning line 602 and the data line 603, wherein the pixel unit is the pixel unit described in the above-mentioned embodiments.

As shown in FIG. 7, the embodiment of the present invention also provides a vertical alignment type liquid crystal display device, including the array substrate 701 described in the above embodiments, and the color filter substrate 702, the color filter substrate is arranged opposite to the array substrate, and the color filter substrate A common electrode (not shown in the figure) is disposed on the substrate 702 ; the liquid crystal layer 703 is disposed between the array substrate 701 and the color filter substrate 702 .

Wherein, the color filter substrate 702 has a common electrode, and the shape of the common electrode is preferably planar. The liquid crystals in the liquid crystal layer 703 are electronegative liquid crystals.

In the embodiment of the present invention, the provided first pixel electrode includes strip-shaped electrode groups connected to each other in at least two directions, each of the strip-shaped electrode groups has a slit between electrodes; The second pixel electrode below, the second pixel electrode at least overlaps the area where the slit of the first pixel electrode is located; the first thin film transistor is used to transmit the data line signal to the first pixel electrode; the second thin film transistor used to transmit the data line signal to the second pixel electrode; the third thin film transistor is used to transmit the data line signal of the first pixel electrode or the second pixel electrode to the voltage dividing electrode; in the pixel structure In this case, the second pixel electrode overlaps the strip-shaped electrode interval area of the first pixel electrode, when the electric field formed between the strip-shaped electrode of the first pixel electrode and the common electrode arranged on the color filter substrate is greater than the strip-shaped electrode interval area and When the electric field formed between the common electrodes on the color filter substrate is set, since the second pixel electrode overlaps the strip-shaped electrode spacing area of the first pixel electrode, the second pixel electrode can be connected to the common electrode on the color filter substrate. An electric field is also formed between them. That is, the liquid crystal located in the interval area of the first pixel electrode and the strip-shaped electrode is subjected to the force of the electric field formed between the second pixel electrode and the common electrode arranged on the color filter substrate, and can generate sufficient deflection, thereby increasing the deflection rate of the liquid crystal. At the same time, the number of dark stripes generated in the first pixel electrode strip-shaped electrode spacing area is reduced.

The above is only a preferred embodiment of the application, and is not intended to limit the application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the application should be included in the scope of the application. within the scope of protection.

While preferred embodiments of the present application have been described, additional changes and modifications to these embodiments can be made by those skilled in the art once the basic inventive concept is appreciated. Therefore, the appended claims are intended to be construed to cover the preferred embodiment and all changes and modifications which fall within the scope of the application.

Obviously, those skilled in the art can make various changes and modifications to the application without departing from the spirit and scope of the application. In this way, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalent technologies, the present application is also intended to include these modifications and variations.

Claims (11)

1. A kind of 1. pixel unit, it is characterised in that including：

   First pixel electrode, first pixel electrode include the strip electrode group at least two directions being connected with each other, each There is slit between electrode in the strip electrode group；

   The second pixel electrode below first pixel electrode, second pixel electrode are at least overlapped in described first The slit region of pixel electrode；

   First film transistor is used for the first pixel electrode transmission data wire signal；

   Second thin film transistor (TFT) is used to transmit the data line signal to second pixel electrode；

   3rd thin film transistor (TFT) is used to transmit the data line signal of first pixel electrode or second pixel electrode To voltage grading electrode；

   The grid of the first film transistor, source electrode, drain electrode are electric with the first scan line, data cable, first pixel respectively Pole electrically connects；

   The grid of second thin film transistor (TFT), source electrode, drain electrode respectively with first scan line, the data cable, described the Two pixel electrodes electrically connect, wherein, the data cable is used for transmission data line signal；

   The grid of 3rd thin film transistor (TFT), source electrode, drain electrode respectively with the second scan line, first pixel electrode or institute State the second pixel electrode, voltage grading electrode electrically connects.
2. 2. pixel unit as claimed in claim 1, it is characterised in that first pixel electrode is in " rice " word structure, including： In " Ha " word arrange two the first strip electrode groups, in " eight " word arrange two the second bar shaped electrode groups, and with each bar Electrode between the connection of shape electrode group, in a cross-shaped mode farmland.
3. 3. pixel unit as claimed in claim 2, it is characterised in that the electrode difference in two the first strip electrode groups The angle between transverse electrode between farmland in electrode is between 35~55 °；In the second bar shaped electrode group in left side The angle between transverse electrode between electrode and farmland in electrode is between 35 °~55 °；The second bar shaped electrode group positioned at right side In electrode and farmland between angle between transverse electrode in electrode between 35 °~65 °.
4. 4. pixel unit as claimed in claim 1, it is characterised in that the spacing of the slit is between 3~20 microns.
5. 5. pixel unit as claimed in claim 1, it is characterised in that second pixel electrode includes being connected with each other at least The strip electrode group of both direction, each has slit between the electrode in the strip electrode group.
6. 6. pixel unit as claimed in claim 1, it is characterised in that second pixel electrode is plane-shape electrode.
7. 7. pixel unit as claimed in claim 1, it is characterised in that the source electrode of the first film transistor and the data Line connects, and the source electrode of second thin film transistor (TFT) is connected with the source electrode of the first film transistor, and second film is brilliant The source electrode of body pipe is connected by the source electrode of the first film transistor with data cable.
8. 8. pixel unit as claimed in claim 1, it is characterised in that the source electrode of the 3rd thin film transistor (TFT) is described second A part in the drain electrode of thin film transistor (TFT).
9. 9. pixel unit as claimed in claim 1, it is characterised in that the voltage grading electrode is overlapping with first pixel electrode Region forms the first storage capacitance；

   The voltage grading electrode forms the second storage capacitance with the second pixel electrode overlapping region.
10. A kind of 10. array base palte, it is characterised in that including：

    The first scan line, the second scan line arranged in pairs；

    The data cable arranged in a crossed manner with first scan line and second scan line；

    The pixel unit being connected with first scan line, second scan line and the data cable, the pixel unit are Pixel unit described in claim 1~9 Arbitrary Term.
11. A kind of 11. vertical alignment liquid crystal display device, it is characterised in that including：

    Array base palte described in claim 10；

    Color membrane substrates, the color membrane substrates are oppositely arranged with the array base palte, and are provided with common electrical on the color membrane substrates Pole；

    Liquid crystal layer, is arranged between the array base palte and the color membrane substrates.