Liquid crystal display element, liquid crystal display device, and alignment method thereof

Abstract

The present application provides a kind of liquid crystal display element, liquid crystal display device and its orientation method, wherein, liquid crystal display element includes: TFT substrate;CF substrate;Liquid crystal layer is arranged between the TFT substrate and the CF substrate;First orientation film is arranged in the TFT substrate side close to the liquid crystal layer;And second orientation film is arranged in the CF substrate side close to the liquid crystal layer, the pretilt angle of liquid crystal molecule in the TFT substrate side is greater than the pretilt angle of liquid crystal molecule in the CF substrate side, and liquid crystal azimuth angle is less than 45 °.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of display technology, and in particular to a liquid crystal display element, a liquid crystal display device and an alignment method thereof. BACKGROUND

[0002] The UV2A technology is a photo-alignment technology developed by Sharp, which can control the alignment of liquid crystal molecules by ultraviolet (UV) irradiation. The key of the UV2A technology is to use a special polymer material as an alignment film, and the polymer main chain on the surface of the alignment film is inclined to the direction of ultraviolet (UV) irradiation. The liquid crystal molecules will be inclined along this main chain direction. The UV2A technology can realize the state of all liquid crystal molecules being inclined to the designed direction through the alignment film. Therefore, when the electric field is loaded, the liquid crystal molecules will be tilted to the same direction at the same time, and thus the response speed is increased to twice the original speed, reaching below 4ms. Therefore, the UV2A technology is favored by consumers.

[0003] As shown in Figure 1 , the UV2A technology can realize the multi-domain wide viewing angle technology by irradiating the TFT substrate and the CF substrate with UV polarized light in different directions. The azimuth angle of the liquid crystal of the UV2A technology is formed by the joint of the PI alignment of the CF substrate side and the TFT substrate side. Both sides are irradiated by horizontal or vertical UV polarized light, so the azimuth angle of the liquid crystal is usually set to 45°. However, in this case, there is a color shift problem when looking at the display horizontally.

[0004] It is known that display products such as televisions pay more attention to the display quality when looking horizontally, and color shift is an important indicator of display quality. Therefore, it is necessary to improve the color shift problem when looking horizontally. SUMMARY

[0005] The present application is completed in view of the above problems, and provides a liquid crystal display element, a liquid crystal display device and an alignment method thereof, which can effectively improve the color shift and ensure the transmittance.

[0006] To solve the above technical problems, the present application provides a liquid crystal display element comprising: a TFT substrate having a first electrode; a CF substrate disposed opposite to the TFT substrate, the CF substrate having a second electrode opposite to the first electrode; a liquid crystal layer disposed between the TFT substrate and the CF substrate; a first alignment film disposed on a side of the TFT substrate close to the liquid crystal layer; and a second alignment film disposed on a side of the CF substrate close to the liquid crystal layer, a pre-tilt angle of a liquid crystal molecule on the TFT substrate side being greater than a pre-tilt angle of a liquid crystal molecule on the CF substrate side, so that a liquid crystal azimuth angle is less than 45°.

[0007] In an embodiment, assuming that the liquid crystal azimuth angle is equal to 45°, the initial pre-tilt angle of the liquid crystal molecule on the TFT substrate side and the initial pre-tilt angle of the liquid crystal molecule on the CF substrate side are both x, in the case of making the liquid crystal azimuth angle less than 45°, the difference between the pre-tilt angle of the liquid crystal molecule on the TFT substrate side and the pre-tilt angle of the liquid crystal molecule on the CF substrate side is y,

[0008] When the pre-tilt angle of the liquid crystal molecule on the CF substrate side is less than x, the difference between the pre-tilt angle of the liquid crystal molecule on the TFT substrate side and the pre-tilt angle of the liquid crystal molecule on the CF substrate side ranges from 0 to -0.79x+70.98.

[0009] In an embodiment, assuming that the liquid crystal azimuth angle is equal to 45°, the UV irradiation fluence on the TFT substrate side and the UV irradiation fluence on the CF substrate side are equal, by increasing the UV irradiation fluence on the CF side, the pre-tilt angle of the liquid crystal molecule on the CF substrate side is less than x.

[0010] In an embodiment, assuming that the liquid crystal azimuth angle is equal to 45°, the initial pre-tilt angle of the liquid crystal molecule on the TFT substrate side and the initial pre-tilt angle of the liquid crystal molecule on the CF substrate side are both x, in the case of making the liquid crystal azimuth angle less than 45°, the difference between the pre-tilt angle of the liquid crystal molecule on the TFT substrate side and the pre-tilt angle of the liquid crystal molecule on the CF substrate side is y,

[0011] When the pre-tilt angle of the liquid crystal molecule on the TFT substrate side is greater than x, the difference between the pre-tilt angle of the liquid crystal molecule on the TFT substrate side and the pre-tilt angle of the liquid crystal molecule on the CF substrate side ranges from 0 to -0.39x+35.27.

[0012] In an embodiment, assuming that the liquid crystal azimuth angle is equal to 45°, the UV irradiation fluence on the TFT substrate side and the UV irradiation fluence on the CF substrate side are equal, by decreasing the UV irradiation fluence on the TFT side, the pre-tilt angle of the liquid crystal molecule on the TFT substrate side is greater than x.

[0013] In one embodiment, assuming that the liquid crystal azimuth angle is equal to 45°, the initial pre-tilt angle of the liquid crystal molecules on the TFT substrate side and the initial pre-tilt angle of the liquid crystal molecules on the CF substrate side are both x, in the case of making the liquid crystal azimuth angle less than 45°, the difference between the pre-tilt angle of the liquid crystal molecules on the TFT substrate side and the pre-tilt angle of the liquid crystal molecules on the CF substrate side is y,

[0014] When the pre-tilt angle of the liquid crystal molecules on the CF substrate side is less than x, and the pre-tilt angle of the liquid crystal molecules on the TFT substrate side is greater than x, the difference between the pre-tilt angle of the liquid crystal molecules on the TFT substrate side and the pre-tilt angle of the liquid crystal molecules on the CF substrate side ranges from 0 to -1.19x+106.25.

[0015] In one embodiment, assuming that the liquid crystal azimuth angle is equal to 45°, the UV irradiation fluence on the TFT substrate side and the UV irradiation fluence on the CF substrate side are equal, by increasing the UV irradiation fluence on the CF side while reducing the UV irradiation fluence on the TFT side, the pre-tilt angle of the liquid crystal molecules on the CF substrate side is less than x, and the pre-tilt angle of the liquid crystal molecules on the TFT substrate side is greater than x.

[0016] In one embodiment, the liquid crystal display element is a UV2A mode.

[0017] To solve the above technical problems, the present application also provides a liquid crystal display device comprising the above-mentioned liquid crystal display element.

[0018] To solve the above technical problems, the present application also provides an alignment method of a liquid crystal display device comprising the above-mentioned liquid crystal display element, in which the pre-tilt angle of the liquid crystal molecules on the TFT substrate side is greater than the pre-tilt angle of the liquid crystal molecules on the CF substrate side, so that the liquid crystal azimuth angle is less than 45°, by increasing the UV irradiation fluence on the CF side and / or reducing the UV irradiation fluence on the TFT side.

[0019] Compared with the prior art, by adjusting the relative relationship between the pre-tilt angles of the liquid crystal molecules on the TFT substrate side and the CF substrate side, so that the pre-tilt angle of the liquid crystal molecules on the CF substrate side is less than the pre-tilt angle of the liquid crystal molecules on the TFT substrate side, and the liquid crystal molecule azimuth angle is less than 45°, the quality of the display device viewed from the horizontal direction can be effectively improved, the overall display quality of the display device can be improved, and the transmittance can be ensured. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the description of the embodiments or the prior art. Obviously, the drawings described below only illustrate some of the embodiments of the present application, and for those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0021] Figure 1 is a schematic diagram of the existing UV2A technology.

[0022] Figure 2 is a schematic diagram of the cross section of the liquid crystal display element in the embodiment of the present application.

[0023] Figure 3 is a schematic diagram of the pre-tilt angle of the liquid crystal molecules in the liquid crystal display element.

[0024] Figure 4 (a) of is a diagram showing the director of the liquid crystal molecules, and (b) is a diagram showing the relationship between the pre-tilt angle of the liquid crystal molecules on the CF substrate side and the liquid crystal director, with the pre-tilt angle of the liquid crystal molecules on the TFT substrate side being constant.

[0025] Figure 5 is a gamma curve diagram when the display device is viewed straight and when the display device is viewed at different angles in the horizontal direction.

[0026] Figure 6 is a diagram showing the change in the difference between the pre-tilt angle of the liquid crystal molecules on the TFT substrate side and the pre-tilt angle of the liquid crystal molecules on the CF substrate side, with the initial pre-tilt angle being different.

[0027] Figure 7 (a) to (c) of are diagrams showing the V-T curve, with the initial pre-tilt angle being different.

[0028] Figure 8 is a diagram showing the change in the luminance ratio of the display device viewed at 60° in the horizontal direction to the display device viewed straight, with the liquid crystal molecules on the CF substrate side having different pre-tilt angles, when the initial pre-tilt angle is 89°. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, and not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative effort belong to the scope of protection of the present application.

[0030] The specific embodiments of the present application will be described in further detail below with reference to the drawings.

[0031] Figure 2 A cross-section of the liquid crystal display element 100 of the present invention is schematically shown. In the present invention, the liquid crystal display element 100 is in UV2A mode, such as... Figure 2 As shown, the liquid crystal display element 100 includes a TFT (Thin Film Transistor) substrate 11 and a CF (Color Filter) substrate 13 disposed opposite to each other, a liquid crystal layer 14, a first alignment film 15, and a second alignment film 16. The liquid crystal layer 14 is disposed between the TFT substrate 11 and the CF substrate 13, and contains liquid crystal molecules 141. Further, the TFT substrate 11 has a plurality of pixel electrodes (first electrodes) 111 arranged in a matrix on the surface of a glass substrate (not shown) opposite to the CF substrate 13. The CF substrate 13 has a common electrode (second electrode) 131 disposed on the surface of the glass substrate (not shown) opposite to the TFT substrate 11. The structures of the TFT substrate 11 and the CF substrate 13 can use existing configurations, therefore, descriptions are omitted. The first alignment film 15 is disposed between the TFT substrate 11 and the liquid crystal layer 14, and the second alignment film 16 is disposed between the CF substrate 13 and the liquid crystal layer 14. The first alignment film 15 and the second alignment film 16 have the following functions: in the liquid crystal display device 1, they control the orientation of the liquid crystal compound in the liquid crystal layer 14 sandwiched between the TFT substrate 11 and the CF substrate 13. When the applied voltage to the liquid crystal layer 14 is less than the threshold voltage (including no voltage applied), the orientation of the liquid crystal molecules 141 in the liquid crystal layer 14 is mainly controlled by the action of the first alignment film 15 and the second alignment film 16. Figure 3 As shown, in this state (also known as the "initial alignment state"), the angle formed by the long axis of the liquid crystal compound relative to the surfaces of the TFT substrate 11 and the CF substrate 13 is called the "pretilt angle θ". Furthermore, in this specification, the "pretilt angle θ" refers to the angle at which the liquid crystal molecules 141 tilt from a direction parallel to the substrate surface (i.e., the surface of the TFT substrate 11 or the CF substrate 13), where the angle parallel to the substrate surface is 0° and the angle perpendicular to the substrate surface is 90°.

[0032] In this embodiment, the pretilt angle of the liquid crystal molecule 141 located on the TFT substrate 11 side is greater than the pretilt angle of the liquid crystal molecule 141 located on the CF substrate 13 side, and the average azimuth angle of the liquid crystal is less than 45°.

[0033] Please see Figure 4 (a) and (b), Figure 4 (a) is a diagram representing the director of the liquid crystal molecules. In the diagram, θ (Theta) represents the pretilt angle of the liquid crystal molecules. (Phi) indicates the azimuth angle of the liquid crystal. Figure 4(b) is a graph showing the relationship between the pretilt angle of the liquid crystal molecules on the CF substrate 13 side and the liquid crystal director when the pretilt angle of the liquid crystal molecules on the TFT substrate 11 side is constant. This graph is based on the relationship between the pretilt angle of the liquid crystal molecules 141 on the TFT substrate 11 side being maintained at 89° and the pretilt angle of the liquid crystal molecules 141 on the CF substrate 13 side and the liquid crystal director. The liquid crystal azimuth angle is in a perpendicular relationship on both the CF substrate 13 side and the TFT substrate 11 side, and therefore, the liquid crystal state at Z = 0.5 GAP is used as a reference. Specifically, when the pretilt angle of the liquid crystal molecules 141 on the CF substrate 13 side is set to 89°, that is, the difference between the pretilt angle of the liquid crystal molecules 141 on the TFT substrate 11 side and the pretilt angle of the liquid crystal molecules 141 on the CF substrate 13 side is 0, the liquid crystal azimuth angle is 45°; when the pretilt angle of the liquid crystal molecules 141 on the CF substrate 13 side is set to less than 89°, that is, the difference between the pretilt angle of the liquid crystal molecules 141 on the TFT substrate 11 side and the pretilt angle of the liquid crystal molecules 141 on the CF substrate 13 side is greater than 0, the liquid crystal azimuth angle is less than 45°; conversely, that is, the difference between the pretilt angle of the liquid crystal molecules 141 on the TFT substrate 11 side and the pretilt angle of the liquid crystal molecules 141 on the CF substrate 13 side is less than 0, the liquid crystal azimuth angle is greater than 45°.

[0034] Further, please refer to Figure 5 , the x-axis represents the gray scale (Gray), and the y-axis represents the luminance. The solid lines 30° and 60° represent the luminance change curves when the display device is viewed at 30° and 60° on the horizontal direction when the liquid crystal azimuth angle is 45°. The dashed lines 30° (exp) and 60° (exp) represent the luminance change curves when the display device is viewed at 30° and 60° on the horizontal direction when the liquid crystal azimuth angle is less than 45°. It can be seen from Figure 5 that when the liquid crystal azimuth angle is set to less than 45°, the liquid crystal phase when the display device is viewed on the horizontal direction is closer to the liquid crystal phase when the display device is viewed straight on. That is, when the liquid crystal azimuth angle is set to less than 45°, the color cast problem when the display device is viewed on the horizontal direction can be effectively improved, and the gamma curve when the display device is viewed on the horizontal direction is also closer to the gamma curve when the display device is viewed straight on.

[0035] Therefore, by the above configuration, the differences in color and other aspects between the case of viewing the display device on the side and the case of viewing the display device straight on can be effectively reduced, that is, the color cast problem can be effectively improved.

[0036] In the present application, the first alignment film 15 and the second alignment film 16 are processed by photo-alignment processing to achieve the liquid crystal azimuth angle being set to less than 45°.

[0037] Further, assuming that the pretilt angle of the liquid crystal molecules 141 on the TFT substrate 11 side is equal to the pretilt angle of the liquid crystal molecules 141 on the CF substrate 13 side and the liquid crystal azimuth angle is equal to 45°, the UV irradiation light quantity of the second alignment film 16 on the CF substrate 13 side and the UV irradiation light quantity of the first alignment film 15 on the TFT substrate 11 side are equal.

[0038] In the present application, the pretilt angle of the liquid crystal molecules 141 on the TFT substrate 11 side can be made greater than the pretilt angle of the liquid crystal molecules 141 on the CF substrate 13 side and the liquid crystal azimuth angle can be made less than 45° in the following manner. When the liquid crystal azimuth angle is 45°, the pretilt angle of the liquid crystal molecules 141 on the TFT substrate 11 side and the pretilt angle of the liquid crystal molecules 141 on the CF substrate 13 side are equal. The pretilt angle in this case is referred to as the initial pretilt angle.

[0039] (i) increasing the UV irradiation light quantity of the second alignment film 16 on the CF substrate 13 side so that the pretilt angle of the liquid crystal molecules 141 on the CF substrate 13 side is less than the initial pretilt angle;

[0040] (ii) decreasing the UV irradiation light quantity of the first alignment film 15 on the TFT substrate 11 side so that the pretilt angle of the liquid crystal molecules 141 on the TFT substrate 11 side is greater than the initial pretilt angle;

[0041] (iii) increasing the UV irradiation light quantity of the second alignment film 16 on the CF substrate 13 side and decreasing the UV irradiation light quantity of the first alignment film 15 on the TFT substrate 11 side so that the pretilt angle of the liquid crystal molecules 141 on the CF substrate 13 side is less than the initial pretilt angle and the pretilt angle of the liquid crystal molecules 141 on the TFT substrate 11 side is greater than the initial pretilt angle.

[0042] It is understood that the UV irradiation light quantity can be controlled by controlling the irradiation time, the equipment power, etc., and is not limited herein.

[0043] It is understood that the optimization of the liquid crystal azimuth angle in the UV2A mode is achieved in the present application by adjusting the pretilt angle of the liquid crystal molecules 141 on the TFT substrate 11 side and / or the pretilt angle of the liquid crystal molecules 141 on the CF substrate 13 side. That is, during the UV irradiation reaction, the UV irradiation light quantity of the second alignment film 16 on the CF substrate 13 side can be increased and / or the UV irradiation light quantity of the first alignment film 15 on the TFT substrate 11 side can be decreased so that the pretilt angle of the liquid crystal molecules 141 on the CF substrate 13 side is less than the pretilt angle of the liquid crystal molecules 141 on the TFT substrate 11 side, i.e., the liquid crystal azimuth angle is less than 45°, thereby effectively improving the color shift problem when viewed horizontally.

[0044] Further, the smaller the pretilt angle of the liquid crystal molecules 141 on the TFT substrate 11 side and the initial pretilt angle of the liquid crystal molecules 141 on the CF substrate 13 side, the greater the range of difference between the pretilt angle of the liquid crystal molecules 141 on the TFT substrate 11 side and the pretilt angle of the liquid crystal molecules 141 on the CF substrate 13 side in the process of making the pretilt angle of the liquid crystal molecules 141 on the TFT substrate 11 side greater than the pretilt angle of the liquid crystal molecules 141 on the CF substrate 13 side.

[0045] Specifically, assuming that the liquid crystal azimuth angle is 45°, the initial pretilt angle of the liquid crystal molecules 141 on the TFT substrate 11 side and the initial pretilt angle of the liquid crystal molecules 141 on the CF substrate 13 side are both x, and the liquid crystal azimuth angle is less than 45°, the pretilt angle of the liquid crystal molecules 141 on the TFT substrate 11 side is a, the pretilt angle of the liquid crystal molecules 141 on the CF substrate 13 side is b, and the difference y (= a - b) between the pretilt angle a of the liquid crystal molecules 141 on the TFT substrate 11 side and the pretilt angle b of the liquid crystal molecules 141 on the CF substrate 13 side can be calculated as follows.

[0046] Referring to Figure 6 When the pretilt angle a of the liquid crystal molecules 141 on the CF substrate 13 side is less than x, the range of difference between the pretilt angle of the liquid crystal molecules 141 on the TFT substrate 11 side and the pretilt angle of the liquid crystal molecules 141 on the CF substrate 13 side satisfies 0 < y ≤ -0.79x + 70.98.

[0047] When the pretilt angle b of the liquid crystal molecules 141 on the TFT substrate 11 side is greater than x, the range of difference between the pretilt angle of the liquid crystal molecules 141 on the TFT substrate 11 side and the pretilt angle of the liquid crystal molecules 141 on the CF substrate 13 side satisfies 0 < y ≤ -0.39x + 35.27.

[0048] When the pretilt angle a of the liquid crystal molecules 141 on the CF substrate 13 side is less than x and the pretilt angle b of the liquid crystal molecules 141 on the TFT substrate 11 side is greater than x, the range of difference between the pretilt angle of the liquid crystal molecules 141 on the TFT substrate 11 side and the pretilt angle of the liquid crystal molecules 141 on the CF substrate 13 side satisfies 0 < y ≤ -1.19x + 106.25.

[0049] The following describes a specific embodiment. Figure 7 To simulate the V-T curves obtained by keeping the pretilt angle on the TFT substrate 11 side unchanged and changing the pretilt angle of the liquid crystal molecules 141 on the CF substrate 13 side relative to the initial pretilt angle at different initial pretilt angles (when the liquid crystal azimuth angle is 45°). Figure 7 (a) to (c) of FIG. 10 show the V-T curves when the initial pretilt angle is 89°, 88°, and 87°, respectively.

[0050] When the initial pre-tilt angle is 89°, 88°, and 87° respectively, and the transmittance range is ±10%, the pre-tilt angle of the liquid crystal molecules 141 on the TFT substrate 11 side is equal to the initial pre-tilt angle, and the difference between the pre-tilt angle of the liquid crystal molecules 141 on the TFT substrate 11 side and the pre-tilt angle of the liquid crystal molecules 141 on the CF substrate 13 side is in the range of [-0.5°, 0.3°], [-1°, 0.6°], and [-2°, 1°] respectively.

[0051] Therefore, when the initial pre-tilt angle of the liquid crystal azimuth angle is 45°, the smaller the initial pre-tilt angle, the larger the difference between the pre-tilt angle of the liquid crystal molecules 141 on the TFT substrate 11 side and the pre-tilt angle of the liquid crystal molecules 141 on the CF substrate 13 side, that is, the range of the variable pre-tilt angle on one side is increased.

[0052] Further, the effects of the present application are described.

[0053] Figure 8 For the case where the initial pre-tilt angle is 89°, the pre-tilt angle of the liquid crystal molecules 141 on the TFT substrate 11 side is 89°, and the pre-tilt angle of the liquid crystal molecules 141 on the CF substrate 13 side is different, the luminance ratio of the display device viewed at 60° and the display device viewed directly in the horizontal direction is shown.

[0054] In Figure 8 , the abscissa represents the gray scale, and the ordinate represents the ratio of the display device viewed at 60° and the display device viewed directly in the horizontal direction, the smaller the ratio, the smaller the difference between the display device viewed at 60° and the display device viewed directly in the horizontal direction, and the smaller the color cast. In combination with Figure 8 , when the pre-tilt angle of the liquid crystal molecules 141 on the CF substrate 13 side is smaller, the difference between the display device viewed at 60° and the display device viewed directly is smaller. The pre-tilt angle of the liquid crystal molecules 141 on the CF substrate 13 side is set to be within 0.5° of the pre-tilt angle of the liquid crystal molecules 141 on the TFT substrate 11 side, which can effectively improve the problem of low color cast.

[0055] Therefore, compared with the prior art, by adjusting the relative relationship between the pre-tilt angles of the liquid crystal molecules 141 on the TFT substrate 11 side and the CF substrate 13 side, the pre-tilt angle of the liquid crystal molecules 141 on the CF substrate 13 side is smaller than the pre-tilt angle of the liquid crystal molecules 141 on the TFT substrate 11 side, and the difference between the two is within an acceptable range, which can effectively improve the quality of the display device viewed at 60° in the horizontal direction, improve the overall display quality of the display device, and ensure the transmittance.

[0056] The present application also provides a liquid crystal display device, which comprises the liquid crystal display element 100 described above and can achieve the same effects.

[0057] The present application also provides an alignment method of a liquid crystal display device including the above-mentioned liquid crystal display element, in which the alignment method of the liquid crystal display device is such that the pretilt angle of the liquid crystal molecules on the TFT substrate side is made larger than the pretilt angle of the liquid crystal molecules on the CF substrate side by increasing the UV irradiation light quantity on the CF side and / or reducing the UV irradiation light quantity on the TFT side, so that the liquid crystal azimuth angle is less than 45°.

[0058] Finally, it should be noted that the above examples are merely intended to illustrate the technical solutions of the present application and not to limit the present application. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present application.

Claims

1. A liquid crystal display element, characterized by comprising: It includes: a TFT substrate having a first electrode; a CF substrate disposed opposite to the TFT substrate, the CF substrate having a second electrode opposite to the first electrode; a liquid crystal layer disposed between the TFT substrate and the CF substrate; a first alignment film disposed on a side of the TFT substrate close to the liquid crystal layer; and a second alignment film disposed on a side of the CF substrate close to the liquid crystal layer, a pretilt angle of liquid crystal molecules on the TFT substrate side is greater than a pretilt angle of liquid crystal molecules on the CF substrate side so that a liquid crystal azimuth angle is less than 45°, assuming that the liquid crystal azimuth angle is equal to 45°, initial pretilt angles of the liquid crystal molecules on the TFT substrate side and the CF substrate side are both x, in the case where the liquid crystal azimuth angle is less than 45°, a difference between the pretilt angle of the liquid crystal molecules on the TFT substrate side and the pretilt angle of the liquid crystal molecules on the CF substrate side is y, when the pretilt angle of the liquid crystal molecules on the CF substrate side is less than x, a range of the difference between the pretilt angle of the liquid crystal molecules on the TFT substrate side and the pretilt angle of the liquid crystal molecules on the CF substrate side satisfies 0 < y ≤ -0.79x + 70.

98.

2. The liquid crystal display element according to claim 1, wherein assuming that the liquid crystal azimuth angle is equal to 45°, UV irradiation fluences on the TFT substrate side and the CF substrate side are equal, the pretilt angle of the liquid crystal molecules on the CF substrate side is made less than x by increasing the UV irradiation fluence on the CF substrate side. It includes:

3. A liquid crystal display element, characterized by comprising: a TFT substrate having a first electrode; a CF substrate disposed opposite to the TFT substrate, the CF substrate having a second electrode opposite to the first electrode; a liquid crystal layer disposed between the TFT substrate and the CF substrate; a first alignment film disposed on a side of the TFT substrate close to the liquid crystal layer; and a second alignment film disposed on a side of the CF substrate close to the liquid crystal layer, a pretilt angle of liquid crystal molecules on the TFT substrate side is greater than a pretilt angle of liquid crystal molecules on the CF substrate side so that a liquid crystal azimuth angle is less than 45°, assuming that the liquid crystal azimuth angle is equal to 45°, initial pretilt angles of the liquid crystal molecules on the TFT substrate side and the CF substrate side are both x, in the case where the liquid crystal azimuth angle is less than 45°, a difference between the pretilt angle of the liquid crystal molecules on the TFT substrate side and the pretilt angle of the liquid crystal molecules on the CF substrate side is y, when the pretilt angle of the liquid crystal molecules on the TFT substrate side is greater than x, a range of the difference between the pretilt angle of the liquid crystal molecules on the TFT substrate side and the pretilt angle of the liquid crystal molecules on the CF substrate side satisfies 0 < y ≤ -0.39x + 35.

27.

4. The liquid crystal display element according to claim 1, wherein assuming that the liquid crystal azimuth angle is equal to 45°, UV irradiation fluences on the TFT substrate side and the CF substrate side are equal, the pretilt angle of the liquid crystal molecules on the CF substrate side is made less than x by increasing the UV irradiation fluence on the CF substrate side. ​ The pretilt angle of the liquid crystal molecules on the TFT substrate side is greater than x by reducing the UV irradiation fluence on the TFT substrate side.

5. A liquid crystal display element, characterized by comprising: It comprises: a TFT substrate having a first electrode; a CF substrate disposed opposite to the TFT substrate, the CF substrate having a second electrode opposite to the first electrode; a liquid crystal layer disposed between the TFT substrate and the CF substrate; a first alignment film disposed on the side of the TFT substrate close to the liquid crystal layer; and a second alignment film disposed on the side of the CF substrate close to the liquid crystal layer, the pretilt angle of the liquid crystal molecules on the TFT substrate side is greater than the pretilt angle of the liquid crystal molecules on the CF substrate side, so that the liquid crystal azimuth angle is less than 45°, assuming that the initial pretilt angle of the liquid crystal molecules on the TFT substrate side and the initial pretilt angle of the liquid crystal molecules on the CF substrate side are both x when the liquid crystal azimuth angle is equal to 45°, the difference between the pretilt angle of the liquid crystal molecules on the TFT substrate side and the pretilt angle of the liquid crystal molecules on the CF substrate side is y when the liquid crystal azimuth angle is less than 45°, when the pretilt angle of the liquid crystal molecules on the CF substrate side is less than x and the pretilt angle of the liquid crystal molecules on the TFT substrate side is greater than x, the difference between the pretilt angle of the liquid crystal molecules on the TFT substrate side and the pretilt angle of the liquid crystal molecules on the CF substrate side ranges from 0 < y ≤ -1.19x+106.

25.

6. The liquid crystal display element according to claim 5, wherein assuming that the UV irradiation fluence on the TFT substrate side and the UV irradiation fluence on the CF substrate side are equal when the liquid crystal azimuth angle is equal to 45°, the pretilt angle of the liquid crystal molecules on the CF substrate side is less than x and the pretilt angle of the liquid crystal molecules on the TFT substrate side is greater than x by increasing the UV irradiation fluence on the CF substrate side and reducing the UV irradiation fluence on the TFT substrate side.

7. The liquid crystal display element according to any one of claims 1 to 6, wherein the liquid crystal display element is a UV2A mode. It comprises the liquid crystal display element according to any one of claims 1 to 7.

8. A liquid crystal display device, characterized by comprising: The liquid crystal display device comprises the liquid crystal display element according to any one of claims 1 to 7, 9. An alignment method of a liquid crystal display device, characterized by, the alignment method of the liquid crystal display device is to make the pretilt angle of the liquid crystal molecules on the TFT substrate side greater than the pretilt angle of the liquid crystal molecules on the CF substrate side by increasing the UV irradiation fluence on the CF substrate side and / or reducing the UV irradiation fluence on the TFT substrate side, so that the liquid crystal azimuth angle is less than 45°. ​

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