CN104714338A - Liquid crystal display panel - Google Patents

Abstract

The invention relates to a liquid crystal display panel, comprising: a first substrate; a first alignment layer disposed on a surface of the first substrate; a second substrate opposite to the first substrate; a second alignment layer disposed on a surface of the second substrate and opposite to the first alignment layer; and a liquid crystal layer disposed between the first alignment layer and the second alignment layer; wherein a ratio of Retardation (retadation) of the first alignment layer to Retardation of the second alignment layer is 0.01-1.

Description

LCD panel

technical field

The invention relates to a liquid crystal display panel, in particular to a transverse electric field liquid crystal display panel.

Background technique

Liquid crystal display panels have the advantages of light weight, thinness, and low energy consumption, so they are widely used in various types of display panels. However, the most common disadvantage of liquid crystal display panels is that their viewing angles are too narrow. The image displayed on the panel will also be different. In order to solve the problem of the narrow viewing angle of the LCD screen, among the wide viewing angle display panels currently proposed, the most widely used ones are the vertical alignment liquid crystal display panel (Vertical Alignment liquid crystal, VA), and the horizontal electric field liquid crystal display panel of the in-plane switching mode. (in-plane switching, IPS).

IPS technology is one of the most advantageous wide viewing angle display panels. Its principle is: the pixel electrode and the common electrode form a plane electric field, so that the liquid crystal molecules rotate horizontally in a plane parallel to the substrate to change the light transmission rate. Due to the IPS liquid crystal display The liquid crystal molecules in the panel always maintain a horizontal direction when rotating, so the viewing angle of the IPS panel is extremely high, and its color shift and saturation performance under large viewing angles are quite excellent. At present, most of them are used in handheld electronic products, such as tablet computers and mobile phones.

However, IPS liquid crystal display panels are prone to abnormal grayscale, lower contrast, or scratches due to poor rotation of liquid crystals, and are also prone to afterimages due to low rotation efficiency of liquid crystal molecules, causing discomfort to viewers. Therefore, based on the above problems, methods for improving IPS liquid crystal display panels have been continuously proposed.

Contents of the invention

The object of the present invention is to provide a liquid crystal display panel, comprising: a first substrate; a first alignment layer disposed on a surface of the first substrate; a second substrate opposite to the first substrate; The second alignment layer is arranged on a surface of the second substrate, and is opposite to the first alignment layer; and a liquid crystal layer is arranged between the first alignment layer and the second alignment layer; wherein, the first alignment layer The ratio of the optical retardation (Retardation) of an alignment layer to the optical retardation of the second alignment layer is 0.01-1.

In a preferred embodiment of the liquid crystal display panel of the present invention, the ratio of the molecular tilt angle of the first alignment layer to the molecular tilt angle of the second alignment layer is 0.2-1.

In a preferred embodiment of the liquid crystal display panel of the present invention, the ratio of the liquid crystal pre-tilt angle of the first alignment layer to the liquid crystal pre-tilt angle of the second alignment layer is 0-1.2.

A preferred embodiment of the liquid crystal display panel of the present invention may further include a spacer disposed on the first substrate or the second substrate.

In a preferred embodiment of the liquid crystal display panel of the present invention, the liquid crystal display panel may be a transverse electric field liquid crystal display panel.

Description of drawings

The implementation of the present invention is illustrated through specific specific examples below, and those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various modifications and changes can be made to the details in this specification for different viewpoints and applications without departing from the spirit of the present invention, among which:

1-5 are schematic diagrams of a method for preparing a lateral electric field liquid crystal display panel according to Embodiment 1 of the present invention.

FIG. 6 is a schematic structural diagram of a lateral electric field liquid crystal display panel according to Embodiment 2 of the present invention.

FIG. 7 is a schematic structural diagram of a lateral electric field liquid crystal display panel according to Embodiment 3 of the present invention.

Detailed ways

Example 1

This embodiment is a method for preparing a lateral electric field liquid crystal display panel according to a preferred implementation aspect of the present invention. First, referring to FIG. 1 , a first substrate 11 is provided. In this embodiment, the first substrate 11 is a color filter substrate, which includes an upper substrate 111 , a black matrix 112 , a color layer 113 , and an insulating layer 114 . However, in other implementations, the color filter used as the first substrate 11 can be a color filter known in the art, and its structure is not limited thereto, and in other implementations, the first substrate 11 A substrate 11 may further include spacers formed thereon. Next, as shown in FIG. 2 , a first alignment layer 13 is formed on the first substrate 11 and covers the first substrate 11 . In this embodiment, the first alignment layer 13 is formed by forming a polyimide film on the first substrate 11, and according to the illumination parameters required for alignment of the polyimide film used, for example, the irradiation The wavelength of UV linear polarized light can be 240-365nm; the illumination can be 5-80mW; the irradiation time can be 1-200 seconds; and the photo-alignment scanning speed can be 4-500mm/s, so as to form the the first alignment layer 13, but the present invention is not limited thereto. In addition, in this embodiment, the first alignment layer 13 is formed through photo-crosslinking and photo-dimerization photo-alignment methods, and in other implementations, photo-isomerization (photo-isomerization) can be used to form the first alignment layer 13. ) method, photo-crosslinking and photo-biquantization method, or photo-degradation method to form the first alignment layer 13, and preferably photo-cross-linking and photo-biquantization method, or photo-degradation method.

3, a second substrate 12 is provided. In this embodiment, the second substrate 12 is a thin film transistor substrate, which includes a lower substrate 121, and a thin film transistor (thin filmtransistor, TFT) 122, and also includes a common electrode (common electrode). electrode) and pixel electrodes (pixel electrode) etc. (not shown in the figure) to provide the lateral electric field of the display panel. The thin film transistor provided by the present invention is a thin film transistor used in a lateral electric field liquid crystal display panel. temperature poly silicon TFT), metal oxide TFT, organic TFT, or other thin film transistors known in the art that can be used in lateral electric field liquid crystal display panels can be used. Next, as shown in FIG. 4 , a second alignment layer 14 is formed on the second substrate 12 and covers the second substrate 12 . In this embodiment, the second alignment layer 14 is formed by forming a polyimide film on the second substrate 12, and then forming the second alignment layer 14 by rubbing. The speed of the roller can be 800-160rpm; the moving speed can be 10-100mm/s; or the brushing depth can be 0.2-0.55mm. However, in other implementations, the brushing parameters can be changed according to the optical retardation required by the alignment layer, the intramolecular tilt angle of the alignment layer, or the pretilt angle of the liquid crystal.

Next, as shown in FIG. 5 , a liquid crystal layer 15 is formed between the first substrate 11 and the second substrate 12 to be in contact with the first alignment layer 13 and the second alignment layer 14 to complete the lateral electric field liquid crystal display panel 10 .

In this embodiment, the optical retardation of the formed first alignment layer 13 is 0.54 nm, and the optical retardation of the second alignment layer 14 is 0.59 nm; the molecular tilt angle in the first alignment layer 13 is 0.4°, The molecular tilt angle in the second alignment layer 14 is 1°; and the liquid crystal pretilt angle of the first alignment layer 13 is 0.22°, and the liquid crystal pretilt angle of the second alignment layer 14 is 2°.

Example 2

The preparation method of this embodiment is substantially the same as that of Embodiment 1, and the preparation method is as shown in FIGS. 1-5 , the difference is that both the first alignment layer 13 and the second alignment layer 14 are formed by photo-alignment method. By adjusting the photo-alignment parameters of the first alignment layer 13 and the second alignment layer 14, alignment layers with different alignment characteristics can be formed, wherein the optical retardation of the formed first alignment layer 13 is 0.5-1.2 nm, and the second The optical retardation of the alignment layer 14 is 0.4-2.5nm; the molecular tilt angle in the first alignment layer 13 is 0.1-0.5°, and the molecular tilt angle in the second alignment layer 14 is 0.1-0.5°; and, the first alignment The liquid crystal pretilt angle of the layer 13 is 0-0.5°, and the liquid crystal pretilt angle of the second alignment layer 14 is 0-0.5°.

In summary, in Embodiment 1, the first alignment layer 13 is formed by photo-alignment method, and the second alignment layer 14 is formed by brushing; in Embodiment 2, the first alignment layer 13 and the second Both alignment layers 14 are formed by photo-alignment method. However, in other embodiments, regardless of whether the second alignment layer 14 is aligned by brushing or photo-alignment, the ratio of the optical retardation of the first alignment layer 13 to the optical retardation of the second alignment layer 14 can be 0.01-1, preferably 0.01-0.95, wherein the optical retardation of the first alignment layer 13 can be 0.001-1.2nm, preferably 0.1-1.2nm, more preferably 0.2-1.2nm, and the second alignment layer The optical retardation of 14 can be 0.2-3nm, preferably 0.4-2.5nm, more preferably 0.5-2.5nm; the ratio of the molecular tilt angle of the first alignment layer 13 to the molecular tilt angle of the second alignment layer 14 can be 0.2-1, preferably 0.2-0.9, wherein the molecular tilt angle of the first alignment layer 13 can be 0.1-0.5°, and the molecular tilt angle of the second alignment layer 14 can be 0.5-2°. The optical retardation and molecular tilt angle of the alignment layer can be measured by instruments such as Polarized-ATR-FTIR, Moritex LayScan, Toyo PI-Checker or Axometrics, but not limited thereto. In addition, the ratio of the liquid crystal pretilt angle of the first alignment layer 13 to the liquid crystal pretilt angle of the second alignment layer 14 may be 0-1.2, wherein the liquid crystal pretilt angle of the first alignment layer 13 may be 0-1°, and the second alignment layer 14 may be 0-1°. The liquid crystal pretilt angle of the alignment layer 14 may be 0.5-2.5°. The liquid crystal pretilt angle can be measured by instruments such as Axometrics Gap, but not limited thereto.

The lateral electric field liquid crystal display panel provided by the present invention has a first alignment layer and a second alignment layer with different alignment properties, and the different optical retardation, molecular tilt angles, and liquid crystals between the first alignment layer and the second alignment layer The pre-tilt angle can avoid the problem of abnormal gray scale and lower contrast caused by poor liquid crystal rotation. In addition, replacing the brushing method with the photo-alignment method to form the alignment layer can reduce the contamination of the alignment layer caused by the brushing process, resulting in abnormal arrangement of liquid crystal molecules.

Example 3

The preparation method of this embodiment is substantially the same as that of Embodiment 1 or Embodiment 2, the difference is that a plurality of spacers 16 are arranged on the first substrate 11 of this embodiment, and the completed transverse electric field liquid crystal display panel 10' is as follows Figure 6 shows. In this embodiment, the properties of the first alignment layer 13 and the second alignment layer 14 such as optical retardation, molecular tilt angle, and liquid crystal molecule pretilt angle may be the same as those described above in the embodiment.

In addition, the pencil hardness of the first alignment layer 13 is 2B-HB, while the pencil hardness of the second alignment layer 14 relative to the spacers 16 is H-5H, and the pencil hardness of the second alignment layer 14 is greater than that of the first alignment layer 13. Pencil hardness. In this embodiment, the second alignment layer 14 opposite to the spacer 16 has a relatively strong hardness, which can avoid peeling off when colliding with the spacer 16 and affect the display characteristics of the liquid crystal display panel. However, in other embodiments of the present invention, the spacer 16 may be disposed on the second substrate. Accordingly, when the spacers 16 are formed on the second substrate 12, the pencil hardness of the first alignment layer 13 is greater than the pencil hardness of the second alignment layer 14, the pencil hardness of the first alignment layer 13 may be H-5H, and the second alignment layer 13 may have a pencil hardness of H-5H. Layer 14 has a pencil hardness of 2B-HB.

Furthermore, when the spacers 16 are formed on the first substrate 12, if the first alignment layer 13 is formed by brushing, the height difference caused by the spacers 16 will easily lead to the problem of uneven alignment of the first alignment layer 13. This further affects the display function of the display panel. Therefore, the first alignment layer 13 is preferably formed using a photo-alignment method, and the second alignment layer 14 can be formed using a brushing method or a photo-alignment method to ensure that the first alignment layer 13 is uniform. alignment properties. Similarly, when the spacers 16 are formed on the second substrate 12, the first alignment layer 13 and the second alignment layer 14 are preferably formed by photo-alignment.

Example 4

This embodiment provides another embodiment of the lateral electric field liquid crystal display panel of the present invention. The completed lateral electric field liquid crystal display panel 20 is shown in FIG. 7, wherein the first substrate 21 is a glass plate; the first alignment layer 23 is formed on one surface of the first substrate 21; the second substrate 22 includes a lower substrate 221, a thin film transistor 222, a color filter 213, and an electrode layer 214; the second alignment layer 24 is formed on the second substrate 22 and opposite to the first alignment layer 23; and spacers 26 are formed on the second substrate. Wherein, the second substrate 22 is a substrate combined with a color filter and a color filter on array (color filter on array), wherein the thin film transistor 222 is a thin film transistor used for a lateral electric field liquid crystal display panel, and also includes The common electrode and the pixel electrode (not shown in the figure) etc. are used to provide the lateral electric field of the display panel.

The first alignment layer 23 is formed by a brushing method, and the second alignment layer 24 is formed by a photo-alignment method. However, in other implementations, both the first alignment layer 23 and the second alignment layer 24 can be formed by photo-alignment. Wherein, the optical retardation amount, molecular tilt angle, and liquid crystal pretilt angle of the first alignment layer 23 and the second alignment layer may be the same as those in Embodiment 3. However, in order to prevent the spacers 26 on the second substrate 22 from colliding with the first alignment layer 23 on the first substrate 21 and cause the first alignment layer 23 to peel off, the pencil hardness of the first alignment layer 23 is greater than that of the second alignment layer 24 The pencil hardness of the first alignment layer 23 has a relatively hard pencil hardness of H-5H, while the pencil hardness of the second alignment layer is 2B-HB. However, in other embodiments, the spacer 26 may be formed on the first substrate 21 or not have the spacer 26 . When the spacer 26 is formed on the first substrate, the pencil hardness of the second alignment layer 24 is greater than the pencil hardness of the first alignment layer 23, the pencil hardness of the second alignment layer 24 can be H-5H, and the first alignment layer 23 The pencil hardness can be 2B-HB.

The above-mentioned embodiments are only examples for convenience of description, and the scope of rights claimed by the present invention should be determined by the scope of the claims, rather than limited to the above-mentioned embodiments.

Claims (16)

1. a display panels, comprising:

One first substrate;

One first both alignment layers, is arranged at one of this first substrate on the surface;

One second substrate, relative to this first substrate;

One second both alignment layers, is arranged at one of this second substrate on the surface, and relative to the first both alignment layers; And

One liquid crystal layer, is arranged between this first both alignment layers and this second both alignment layers;

Wherein, the ratio of the light amount of hysteresis of this first both alignment layers and the light amount of hysteresis of this second both alignment layers is 0.01-1.

2. display panels as claimed in claim 1, wherein, the ratio of the light amount of hysteresis of this first both alignment layers and the light amount of hysteresis of this second both alignment layers is 0.01-0.95.

3. display panels as claimed in claim 1, wherein, the light amount of hysteresis of this first both alignment layers is 0.001-1.2nm; The light amount of hysteresis of this second both alignment layers is 0.2-3nm.

4. display panels as claimed in claim 1, wherein, the ratio at the molecule tilt angle of this first both alignment layers and the molecule tilt angle of this second both alignment layers is 0.2-1.

5. display panels as claimed in claim 4, wherein, the ratio at the molecule tilt angle of this first both alignment layers and the molecule tilt angle of this second both alignment layers is 0.2-0.9.

6. display panels as claimed in claim 1, wherein, the molecule tilt angle of this first both alignment layers is 0.1-0.5 °; The molecule tilt angle of this second both alignment layers is 0.5-2 °.

7. display panels as claimed in claim 1, wherein, the ratio of the liquid crystal pretilt angle of this first both alignment layers and the liquid crystal pretilt angle of this second both alignment layers is 0-1.2.

8. display panels as claimed in claim 1, wherein, the liquid crystal pretilt angle of this first both alignment layers is 0-1 °; The liquid crystal pretilt angle of this second both alignment layers is 0.5-2.5 °.

9. display panels as claimed in claim 1, wherein, at least one of this first both alignment layers and this second both alignment layers is photo-alignment layer.

10. display panels as claimed in claim 1, wherein, at least one of this first both alignment layers and this second both alignment layers is brushing both alignment layers.

11. display panels as claimed in claim 1, also comprise a separation material, are arranged on this first substrate or this second substrate.

12. display panels as claimed in claim 11, wherein, when this separation material is arranged on this first substrate, the pencil hardness of this second both alignment layers is greater than the pencil hardness of this first both alignment layers.

13. display panels as claimed in claim 12, wherein, the pencil hardness of this first both alignment layers is 2B-HB; And the pencil hardness of this second both alignment layers is H-5H.

14. display panels as claimed in claim 11, wherein, this first substrate is colored filter, and this second substrate is thin film transistor base plate.

15. display panels as claimed in claim 11, wherein, this second substrate comprises thin film transistor (TFT) and colored filter.

16. display panels as claimed in claim 1, wherein, this display panels is a kind of transverse electric field display panels.