CN101893779B - LCD panel - Google Patents

Abstract

The invention discloses a liquid crystal display panel, which comprises an active element array substrate, an opposite substrate and a liquid crystal layer. The active element array substrate comprises a plurality of pixel electrodes, each pixel electrode comprises a plurality of groups of strip patterns extending along different directions, the width of each strip pattern is L, and the interval between two adjacent strip patterns is S. The opposite substrate is arranged above the active element array substrate. The liquid crystal layer is configured between the active element array substrate and the opposite substrate, wherein the cavity gap between the active element array substrate and the opposite substrate is d, the birefringence of the liquid crystal layer is delta n, the dielectric anisotropy of the liquid crystal layer is delta epsilon, and S/| delta epsilon | < 2.8 × delta n × d.

Description

LCD panel

technical field

The present invention relates to a liquid crystal display panel, and in particular to a polymer stabilized alignment (Polymer Stabilized Alignment, PSA) liquid crystal display panel.

Background technique

In the development of displays, with the advancement of optoelectronic technology and semiconductor manufacturing technology, liquid crystal displays with superior characteristics such as high image quality, good space utilization efficiency, low power consumption, and no radiation have gradually become the mainstream of the market.

During the manufacturing process of the liquid crystal display panel, an alignment film is formed on the two substrates so that the liquid crystal molecules have a specific arrangement. The existing method for forming an alignment film is to apply an alignment material first, and then perform an alignment process on the alignment material. The alignment process can be divided into a contact alignment process and a non-contact alignment process. Although the non-contact alignment process can solve problems such as static electricity and particle contamination caused by contact friction alignment, it often suffers from the problem of insufficient anchoring energy of the alignment surface. If the anchoring energy of the alignment surface is insufficient, the display quality of the liquid crystal display panel will often be poor. In order to solve the above problems, the existing technology has proposed a polymer stable alignment technology. This technology is to mix an appropriate amount of monomer compound (monomer) into the liquid crystal, and then place the liquid crystal mixed with the monomer compound under heating. Heating on the device to reach the isotropic (Isotropy) state. Then, when the mixture of liquid crystals and monomer compounds cools down to room temperature, the liquid crystal molecules return to a nematic state. At this time, a mixture of liquid crystal and monomer compound is injected into the liquid crystal cell and a voltage is applied. When voltage is applied to stabilize the alignment of liquid crystal molecules, ultraviolet light or heating is used to polymerize monomer compounds to form a polymer layer, thereby achieving the purpose of stable alignment.

Generally speaking, the pixel electrode in the polymer stabilized alignment liquid crystal display panel has multiple sets of striped patterns extending along different directions, and alignment slits (alignment slits) are formed between each striped pattern, and these striped patterns extend along different directions. The stripe pattern extending in the direction can control the arrangement of liquid crystal molecules to achieve the effect of wide viewing angle.

In order to further improve the response speed of the polymer-stabilized alignment liquid crystal display panel, reducing the cell gap of the liquid crystal display panel is one of the ways. However, when the cavity gap of the liquid crystal display panel decreases, the liquid crystal efficiency of the liquid crystal display panel decreases accordingly. For example, when the crystal cavity gap of the polymer stabilized alignment liquid crystal display panel is reduced, due to the twist in azimuthal angle of the liquid crystal molecules, dark lines will appear in the area corresponding to the alignment slit, and these dark lines will be As a result, the transmittance of the liquid crystal display panel decreases. Therefore, how to balance the response speed and transmittance of the liquid crystal display panel has become one of the issues that the industry pays attention to.

Contents of the invention

The invention provides a liquid crystal display panel, which has good liquid crystal efficiency (transmittance).

The invention provides a liquid crystal display panel, which includes an active element array substrate, an opposite substrate and a liquid crystal layer. The active device array substrate includes a plurality of pixel electrodes, and each pixel electrode includes multiple sets of striped patterns extending along different directions, the width of each striped pattern is L, and the interval between two adjacent striped patterns is S. The opposite substrate is disposed above the active device array substrate. The liquid crystal layer is arranged between the active element array substrate and the opposite substrate, wherein the cavity gap between the active element array substrate and the opposite substrate is d, the birefringence of the liquid crystal layer is Δn, and the dielectric coefficient of the liquid crystal layer is different The squareness is Δε, and S/|Δε|≤2.8×Δn×d.

In an embodiment of the present invention, d is, for example, less than 3.5 microns. In other words, the liquid crystal display panel has a smaller cell gap. For example, 2 microns≤d≤3.5 microns, or 1.5 microns≤d≤3.5 microns.

In an embodiment of the present invention, 0<S≦d−0.3 μm. For example, 0 microns<S≤4 microns, or 1.5 microns≤S≤3.5 microns.

In an embodiment of the present invention, the aforementioned liquid crystal display panel may further include a first alignment film and a first polymer layer, wherein the first alignment film covers the pixel electrodes, and the first polymer layer is located on the first alignment film between the liquid crystal layer.

In an embodiment of the present invention, the aforementioned opposite substrate includes a common electrode.

In an embodiment of the present invention, the aforementioned liquid crystal display panel may further include a second alignment film and a second polymer layer, wherein the second polymer layer covers the common electrode, and the second polymer layer is located in the second alignment layer. between the film and the liquid crystal layer.

In an embodiment of the present invention, the aforementioned active device array substrate may further include a plurality of active devices, and each active device is electrically connected to one of the pixel electrodes respectively.

In an embodiment of the present invention, the aforementioned L/S is about 3.5 microns/2.5 microns.

In an embodiment of the present invention, 2.5≤Δε≤5.5.

In an embodiment of the present invention, 0.05≦Δn≦0.15.

Based on the above, since the present invention adjusts the spacing (S) between two adjacent strip patterns in the pixel electrode, and selects appropriate liquid crystal materials (Δε, Δn, d) to meet the requirement of S/|Δε|≤2.8×Δn×d Inequality, so the present invention can take into account both the response speed of the liquid crystal display panel and the liquid crystal efficiency (transmittance).

The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments, but not as a limitation of the present invention.

Description of drawings

FIG. 1A is a schematic cross-sectional view of a polymer stabilized alignment liquid crystal display panel according to an embodiment of the present invention.

FIG. 1B is a schematic diagram of a pixel electrode according to an embodiment of the present invention.

FIG. 2A is a schematic diagram of an active device array substrate according to an embodiment of the present invention.

FIG. 2B is a schematic diagram of an opposite substrate according to an embodiment of the present invention.

Among them, reference signs:

100: polymer stabilized alignment liquid crystal display panel

110: active element array substrate

112: pixel electrode

114: Active components

120: opposite substrate

122: shading layer

124: Color filter film

126: common electrode

130: liquid crystal layer

140a: first alignment film

140b: second alignment film

150a: first polymer layer

150b: the second polymer layer

SL: scan line

DL: data line

Detailed ways

1A is a schematic cross-sectional view of a polymer stabilized alignment liquid crystal display panel according to an embodiment of the present invention, and FIG. 1B is a schematic view of a pixel electrode according to an embodiment of the present invention. Please refer to FIG. 1A and FIG. 1B , the polymer stabilized alignment liquid crystal display panel 100 of this embodiment includes an active device array substrate 110 , a pair of facing substrates 120 and a liquid crystal layer 130 . The active device array substrate 110 of this embodiment includes a plurality of pixel electrodes 112, and each pixel electrode 112 includes multiple sets of striped patterns P extending in different directions, the width of each striped pattern P is L, and two adjacent striped patterns P The interval of the pattern P is S. The opposite substrate 120 is arranged above the active element array substrate 110, and the liquid crystal layer 130 is arranged between the active element array substrate 110 and the opposite substrate 120, wherein the cavity gap between the active element array substrate 110 and the opposite substrate 120 is d, that is, the thickness of the liquid crystal layer 130 is d. In addition, the birefringence of the liquid crystal layer 130 is Δn, and the dielectric anisotropy of the liquid crystal layer 130 is Δε. In this embodiment, S, Δε, Δn and d need to satisfy the following inequality (1):

S/|Δε|≤2.8×Δn×d  …(1)

Referring to FIG. 1A and FIG. 1B , the cavity gap d of this embodiment is, for example, less than about 3.5 microns. In other words, the polymer-stabilized alignment liquid crystal display panel 100 of this embodiment has a relatively small crystal-cavity gap (usually d≤3.5 μm). For example, 2 microns≤d≤3.5 microns, or 1.5 microns≤d≤3.5 microns. In addition, the dielectric anisotropy Δε and the birefringence Δn of the liquid crystal layer 130 need to satisfy the following relations (2) and (3):

2.5≤Δε≤5.5 …(2)

0.05≤Δn≤0.15 …(3)

In this embodiment, 0<S≤d−0.3 microns, for example, 0 microns<S≤3.2 microns, or 1.5 microns≤S≤3.2 microns. In a feasible embodiment, the aforementioned L/S is, for example, about 3.5 microns/2.5 microns or about 3.8 microns/2.2 microns, but not limited thereto. In other embodiments, other L/S values may also be used, for example: 5 microns/3 microns, 4 microns/3 microns, 4 microns/2.5 microns, 3 microns/2 microns, and so on.

Compared with the situation where L/S is 5 microns/3 microns, Δn=0.091, and Δε=-3.8 (liquid crystal efficiency is defined as 100%), when L/S is 3.5 microns/2.5 microns, Δn=0.104, Δε= When -3.1, its liquid crystal efficiency is 101.3%, and when L/S is 3.8 microns/2.2 microns, Δn=0.104, Δε=-3.1, its liquid crystal efficiency is 100.03%, as shown in the following table. It is worth noting that when the L/S is 5 microns/3 microns, Δn=0.104, Δε=-3.1 (the relational expression of S/|Δε|≤2.8×Δn×d is not satisfied), the liquid crystal efficiency is only 93 %.

d Δn Δε L/S LCD efficiency 3.8 microns 0.091 -3.8 5 microns/3 microns 100.0% 3.3 microns 0.104 -3.1 5 microns/3 microns 93.0% 3.3 microns 0.104 -3.1 3.5 microns/2.5 microns 101.3% 3.3 microns 0.104 -3.1 3.8 microns/2.2 microns 100.03%

FIG. 2A is a schematic diagram of an active device array substrate according to an embodiment of the present invention. 1A and FIG. 2A, in this embodiment, the active element array substrate 110 includes a plurality of scanning lines SL, a plurality of data lines DL, a plurality of pixel electrodes 112 and a plurality of active elements 114, wherein the scanning lines SL and data The lines DL are staggered to define a plurality of pixel areas (not marked), each of which is provided with at least one pixel electrode 112 and at least one active element 114, and each pixel electrode 112 communicates with the corresponding active element 114 respectively. The scan line SL and the data line DL are electrically connected. For example, the active device array substrate 110 is a thin film transistor array substrate (TFT array substrate).

FIG. 2B is a schematic diagram of an opposite substrate according to an embodiment of the present invention. Please refer to FIG. 1A and FIG. 2B , in this embodiment, the opposite substrate 120 includes a light shielding layer 122 , a plurality of color filter films 124 and a common electrode 126 (shown in FIG. 1A ). In other words, the opposite substrate 120 of this embodiment is a color filter substrate. It should be noted that the light-shielding layer 122 and the color filter layer 124 on the opposite substrate 120 in this embodiment are optional components. There is no need to fabricate the color filter layer 124 on the upper surface, and when the active device array substrate 110 is fabricated using BOA technology, the opposite substrate 120 does not need to fabricate the light shielding layer 122 and the color filter layer 124 .

In the process of fabricating the polymer stable alignment liquid crystal display panel 100, in order to obtain a stable alignment of the liquid crystal molecules in the liquid crystal layer 130, the first method of this embodiment is to mix an appropriate amount of monomer compounds into the liquid crystal, and then, The liquid crystal mixed with the monomer compound is placed on a heater and heated to an isotropic state. When the mixture of liquid crystal and monomer compound cools down to room temperature, the liquid crystal molecules will return to the nematic state. At this time, the mixture of liquid crystal and monomer compound is injected into the liquid crystal cell (also called the cell gap) and a voltage is applied. Wherein, the liquid crystal cell is a space formed by the active element array substrate 110 and the opposite substrate 120 . When voltage is applied to stabilize the arrangement of liquid crystal molecules, ultraviolet light or heating is used to polymerize monomer compounds to form a polymer layer. The second way is that the liquid crystal layer 130 is not doped with a monomer compound, and the liquid crystal layer 130 without a monomer compound is injected into a liquid crystal cell (also called a crystal cavity gap), and the liquid crystal cell is formed by an array of active elements. The space formed by the substrate 110 and the opposite substrate 120 , and the surfaces of the active device array substrate 110 and the opposite substrate 120 respectively have a first alignment compound film (not shown) and a second alignment compound film (not shown). In particular, the first alignment mixture film (not shown) and the second alignment mixture film (not shown) are also mixed with monomer compounds in addition to the main components of the alignment film. Therefore, when a voltage is applied to the liquid crystal cell and the monomer compound is polymerized by ultraviolet light or heat, the monomer compound will be polymerized into a polymer layer on the first alignment mixture film (not shown) and the second alignment mixture film (not marked) on the surface. That is to say, the main components of the alignment films of the first alignment mixture film (not shown) and the second alignment mixture film (not shown) respectively form the first alignment film 140a and the second alignment film 140b, and the incorporated monomer compound The polymerized polymer layers are respectively the first polymer layer 150a and the second polymer layer 150b and are respectively located on the surface of the first alignment film 140a and the second alignment film 140b or are respectively located on the surface of the first alignment film 140a and the second alignment film 140a. Two alignment films 140b are on the surface, as shown in FIG. 1A. Furthermore, the method of injecting the liquid crystal layer 130 into the liquid crystal cell includes vacuum injection and one drop filling (ODF). The embodiment of the present invention is exemplified by the vacuum injection method, but is not limited thereto. As can be seen from FIG. 1A, the polymer-stabilized alignment liquid crystal display panel 100 of this embodiment may further include a first alignment film 140a, a second alignment film 140b, a first polymer layer 150a, and a second polymer layer 150b, wherein the first alignment The film 140a covers the active element array substrate 110, the second polymer layer 140b covers the opposite substrate 120, and the first polymer layer 150a is located between the first alignment film 140a and the liquid crystal layer 130, so as to stabilize the The alignment state of the liquid crystal molecules of an alignment film 140a, and the second polymer layer 150b is located between the second alignment film 140b and the liquid crystal layer 130, so as to stabilize the alignment state of the liquid crystal molecules in the liquid crystal layer 130 that are closer to the second alignment film 140b .

Based on the above, since the present invention adjusts the spacing (S) between two adjacent strip patterns in the pixel electrode, and selects appropriate liquid crystal materials (Δε, Δn, d) to meet the requirement of S/|Δε|≤2.8×Δn×d Inequality, so the present invention can take into account both the response speed of the liquid crystal display panel and the liquid crystal efficiency (transmittance).

Certainly, the present invention also can have other various embodiments, without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and deformations according to the present invention, but these corresponding changes All changes and modifications should belong to the protection scope of the claims of the present invention.

Claims (13)

1. a display panels is characterized in that, comprising:

One active component array base board comprises a plurality of pixel electrodes, and respectively this pixel electrode comprises the strip patterns that many groups are extended along different directions, and respectively the width of this strip pattern is L, and two adjacent strip patterns be spaced apart S;

One subtend substrate is disposed at this active component array base board top; And

One liquid crystal layer, be disposed between this active component array base board and this subtend substrate, wherein the cell gap between this active component array base board and this subtend substrate is d, the birefraction of this liquid crystal layer is Δ n, the dielectric coefficient anisotropy of this liquid crystal layer is Δ ε, and S/| Δ ε |≤2.8 * Δ n * d.

2. display panels according to claim 1 is characterized in that, 2 microns≤d≤3.5 microns.

3. display panels according to claim 1 is characterized in that, 1.5 microns≤d≤3.5 microns.

4. display panels according to claim 1 is characterized in that, 0＜S≤d-0.3 micron.

5. display panels according to claim 1 is characterized in that, 0＜S≤4 micron.

6. display panels according to claim 1 is characterized in that, 1.5 microns≤S≤3.5 microns.

7. display panels according to claim 1 is characterized in that, also comprises:

One first alignment film covers those pixel electrodes; And

One first macromolecule layer is between this first alignment film and this liquid crystal layer.

8. display panels according to claim 1 is characterized in that, this subtend substrate comprises a common electrode.

9. display panels according to claim 8 is characterized in that, also comprises:

One second alignment film covers this common electrode; And

One second macromolecule layer is between this second alignment film and this liquid crystal layer.

10. display panels according to claim 1 is characterized in that this active component array base board also comprises a plurality of active members, and respectively this active member electrically connects with a pixel electrode wherein respectively.

11. display panels according to claim 1 is characterized in that, L/S is about 3.5 microns/2.5 microns.

12. display panels according to claim 1 is characterized in that, 2.5≤Δ ε≤5.5.

13. display panels according to claim 1 is characterized in that, 0.05≤Δ n≤0.15.

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