A liquid crystal panel for improving VA black level

Abstract

This utility model relates to a liquid crystal panel for improving VA blackness, comprising an incident polarizer, a first structural layer, a second structural layer, and an exit polarizer stacked along the incident end direction to the exit end direction. The first structural layer includes a first ITO layer, a first PI layer, a first liquid crystal layer, a second PI layer, and a second ITO layer stacked along the incident end direction to the exit end direction. The second structural layer includes a third PI layer, a second liquid crystal layer, and a fourth PI layer stacked along the incident end direction to the exit end direction. The liquid crystals in the first liquid crystal layer and the liquid crystals in the second liquid crystal layer have the same angle of inclination relative to the vertical direction when not powered, and the angle between the projection of the inclination directions of the liquid crystals in the first liquid crystal layer and the liquid crystals in the second liquid crystal layer onto the horizontal plane is 90 degrees. This utility model, through the setting of the second structural layer, enables the second liquid crystal layer to play a role in light correction, reducing light leakage caused by the unavoidable angle between the liquid crystal and the vertical direction due to friction with the liquid crystal.

Description

Technical Field

[0001] This utility model relates to a VA liquid crystal panel, and more particularly to a liquid crystal panel for improving the blackness of VA. Background Technology

[0002] The description in this section provides only background information related to the disclosure of this utility model and does not constitute prior art.

[0003] Currently, due to material and friction, the liquid crystal molecules in VA (Vertical Alignment) panel products are not completely perpendicular to the PI (Polyimide) layer (primarily used as a liquid crystal alignment film to control the initial alignment direction and pretilt angle of liquid crystal molecules). There is an angle θ between the VA and the plane normal in the friction direction. Since the liquid crystal molecules themselves cannot achieve an ideal vertical state, light leakage will inevitably occur.

[0004] It should be noted that the above introduction to the technical background is only for the purpose of providing a clear and complete explanation of the technical solutions of this utility model and facilitating understanding by those skilled in the art. It should not be assumed that these technical solutions are known to those skilled in the art simply because they have been described in the background section of this utility model. Utility Model Content

[0005] The purpose of this invention is to provide a liquid crystal panel that improves the blackness of VA (Volume Amplitude). By setting a second structural layer, the second liquid crystal layer can play a role in light correction, reducing light leakage caused by the unavoidable angle between the liquid crystal and the direction of friction.

[0006] To achieve the above objectives, this utility model discloses a liquid crystal panel for improving VA blackness. The liquid crystal panel has an incident end and an exiting end disposed opposite to each other. The liquid crystal panel includes an incident polarizer, a first structural layer, a second structural layer, and an exiting polarizer stacked along the direction from the incident end to the exiting end.

[0007] The first structural layer includes a first ITO layer, a first PI layer, a first liquid crystal layer, a second PI layer, and a second ITO layer stacked along the incident end direction to the emission end direction;

[0008] The second structural layer includes a third PI layer, a second liquid crystal layer, and a fourth PI layer stacked along the incident end direction to the exit end direction;

[0009] The projection of the transmission axis of the incident polarizer and the liquid crystal friction direction onto the horizontal plane is at a 45-degree angle.

[0010] The liquid crystals in the first liquid crystal layer and the liquid crystals in the second liquid crystal layer have the same angle of inclination relative to the vertical direction when no electricity is applied, and the angle between the projection of the inclination directions of the liquid crystals in the first liquid crystal layer and the liquid crystals in the second liquid crystal layer onto the horizontal plane is 90 degrees.

[0011] As a further description of the above technical solution, the thickness of the first liquid crystal layer along the vertical direction is the same as the thickness of the second liquid crystal layer along the vertical direction.

[0012] As a further description of the above technical solution, an upper glass substrate is disposed between the incident polarizer and the upper ITO layer.

[0013] As a further description of the above technical solution, a middle glass substrate is disposed between the second ITO layer and the third PI layer.

[0014] As a further description of the above technical solution, a lower glass substrate is disposed between the fourth PI layer and the emitted polarizer.

[0015] As a further description of the above technical solution, the upper glass substrate, the middle glass substrate, and the lower glass substrate have the same thickness along the vertical direction.

[0016] As a further description of the above technical solution, the first PI layer, the second PI layer, the third PI layer, and the fourth PI layer have the same thickness along the vertical direction.

[0017] Based on the above technical solution, the beneficial effects of this utility model are as follows:

[0018] This invention relates to a liquid crystal panel for improving the blackness of VA (Video Residue Added) liquid crystals. By incorporating a second structural layer, the second liquid crystal layer corrects light emission, reducing light leakage caused by the unavoidable angle between the rubbing directions of the liquid crystals. Specifically, this invention involves superimposing a second liquid crystal layer whose rubbing direction is perpendicular to that of the first liquid crystal layer in the first structural layer, while maintaining identical parameters. This reverses the optical path difference between the x and y axes, ensuring that the emitted polarized light produces linearly polarized light with the same polarization direction as the perpendicularly incident polarized light. This polarization is perpendicular to the polarization direction of the emitted polarizer, minimizing light leakage and improving the blackness of the VA product's base color.

[0019] To further understand the features and technical content of this utility model, please refer to the following detailed description and drawings of this utility model. However, the drawings provided are for reference and illustration only and are not intended to limit this utility model. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments or prior art of this specification, the drawings used in the description of the embodiments or prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this specification. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a cross-sectional schematic diagram of a liquid crystal panel for improving VA blackness provided in the embodiments of this specification;

[0022] Figure 2 This is a cross-sectional view of a liquid crystal panel for improving VA blackness provided in the embodiments of this specification after being rotated 90 degrees along the vertical direction;

[0023] In the picture:

[0024] 1. First structural layer; 11. First ITO layer; 12. First PI layer; 13. First liquid crystal layer; 14. Second PI layer; 15. Second ITO layer;

[0025] 2. Second structural layer; 21. Third PI layer; 22. Second liquid crystal layer; 23. Fourth PI layer;

[0026] 3. Incident polarizer;

[0027] 4. Outgoing polarizer;

[0028] 5. Place the glass substrate;

[0029] 6. Medium glass substrate;

[0030] 7. Lower glass substrate. Detailed Implementation

[0031] To enable those skilled in the art to better understand the technical solutions in this specification, the technical solutions in the embodiments of this specification will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this specification, and not all embodiments. Based on the embodiments in this specification, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this specification.

[0032] The following specific embodiments illustrate the implementation of this utility model. Those skilled in the art can understand the advantages and effects of this utility model from the content disclosed in this specification. This utility model can be implemented or applied through other different specific embodiments, and various details in this specification can also be modified and changed based on different viewpoints and applications without departing from the concept of this utility model. Furthermore, the accompanying drawings of this utility model are for simple illustration only and are not depictions of actual dimensions, as stated in advance. The following embodiments will further describe the relevant technical content of this utility model in detail, but the disclosed content is not intended to limit the scope of protection of this utility model.

[0033] It should be understood that while terms such as "first," "second," and "third" may be used in this document to describe various components or signals, these components or signals should not be limited by these terms. These terms are primarily used to distinguish one component from another, or one signal from another. Furthermore, the term "or" as used herein should, as appropriate, include any combination of one or more of the related listed items.

[0034] Please see Figure 1-2 This embodiment describes a liquid crystal panel for improving VA blackness. The liquid crystal panel has an incident end and an exit end disposed opposite to each other. The liquid crystal panel includes an incident polarizer 3, a first structural layer 1, a second structural layer 2, and an exit polarizer 4, which are stacked along the direction from the incident end to the exit end.

[0035] The first structural layer 1 includes a first ITO layer 11, a first PI layer 12, a first liquid crystal layer 13, a second PI layer 14, and a second ITO layer 15 stacked along the incident end direction to the emission end direction;

[0036] The second structural layer 2 includes a third PI layer 21, a second liquid crystal layer 22, and a fourth PI layer 23 stacked along the incident end direction to the emission end direction;

[0037] The projection of the transmission axis of the incident polarizer 3 onto the horizontal plane with the direction of liquid crystal friction is at a 45-degree angle.

[0038] The liquid crystals in the first liquid crystal layer 13 and the liquid crystals in the second liquid crystal layer 22 have the same angle of inclination relative to the vertical direction when no electricity is applied, and the angle between the projection of the inclination direction of the liquid crystals in the first liquid crystal layer 13 and the liquid crystals in the second liquid crystal layer 22 onto the horizontal plane is 90 degrees.

[0039] Based on the above structure, please refer to Figure 1-2By superimposing a second liquid crystal layer 22 whose friction direction is perpendicular to the friction direction of the first liquid crystal layer 13 in the first structural layer 1 and whose other parameters are exactly the same, the optical path difference between the x-axis and y-axis is reversed, ensuring that the emitted polarized light and the perpendicularly incident polarized light produce linearly polarized light with the same polarization direction, making it perpendicular to the polarization direction of the emitted polarizer, thereby minimizing light leakage of emitted light and improving the blackness of the background color of VA products.

[0040] Taking the comparative example, without the second structural layer 2, due to material and friction, the first liquid crystal layer 13 is not completely perpendicular to the first PI layer 12 or the second PI layer 14. The vertical direction is perpendicular to the friction direction, and there will be an angle θ between the friction direction and the plane perpendicular direction. When light is perpendicularly incident on the plane of the liquid crystal screen, there will be an angle greater than n parallel to the friction direction. o equivalent refractive index Where, n o For the ideal equivalent refractive index perpendicular to the friction direction, n e Let n' be the extraordinary refractive index of light along the long axis (x-axis) of the liquid crystal molecules, and n' be the effective refractive index with an actual tilt angle θ. o and n e The equivalent value obtained by mixing;

[0041] Therefore, light travels at different speeds in the two refractive index directions, resulting in a phase difference caused by the optical path difference between the two directions. Where d is the total thickness of the liquid crystal layer, and λ is the wavelength of the light;

[0042] Based on this, the linearly polarized light intensity I of the polarizer incident at 45° is... 2 After passing through the liquid crystal molecules, it forms elliptically polarized light with its major axis in the original polarization direction. That is, there will be light intensity on the exiting polarizer 4, whose polarization direction is perpendicular to the polarization direction of the incident polarizer. The light emitted did not result in the product achieving its maximum blackness; among them, E... x E represents the oscillation of the electric field along the x-axis of polarized light. γ I represents the oscillation of the electric field along the y-axis polarized light, and I represents the electric field amplitude. 2 ωt represents the light intensity (strength) being proportional to the square of the amplitude, kz represents the phase of the light oscillation changing over time, and kz is the phase delay caused by this propagation.

[0043] The following is an embodiment based on the method of this utility model, which solves the problem that the blackness of the product does not reach the blackest level.

[0044] In this embodiment, n is set without power. o For 1.5, n e=1.6, with a tilt of θ≈8.5° in the friction direction, therefore, the equivalent refractive index n2′≈1.502 in the x-direction of the first structural layer 1 is higher than n o =1.5 is slightly larger, resulting in a refractive index difference Δn2 = n2′ - n o ≈0.002. In this embodiment, the incident polarizer 3 is set to be incident at 45°. The incident polarizer 3 makes the components of the electric field in the x and y directions equal. Let E be the linearly polarized light after the incident light passes through the polarizer. x =E y =cos(ωt), without power applied, for the emitted light of the first liquid crystal layer but This results in a phase difference generated in the first structural layer 1. The refractive index difference is Δn2=n′2-n o =0.002, and in the second structural layer 2, since the second liquid crystal layer 22 has an angle perpendicular to the first liquid crystal layer 13 around the vertical direction, the emitted light becomes When the phase difference between the two directions is eliminated, the polarization state of the outgoing light is the same as that of the incident light. At this time, since the polarization transmission axis of the lower polarizer is perpendicular to it, the light cannot pass through.

[0045] Based on the above embodiments, when power is applied, the first liquid crystal layer 13 is powered through the first ITO layer 11 and the second ITO layer 15, and the refractive index in the x-direction is assumed to be a very high refractive index n. e =1.60, the y-direction still has the ordinary refractive index n o =1.50, the refractive index in the liquid crystal tilting direction is n′1=n e The refractive index difference Δn1 = n′1 - n o =n e -n o =0.10, for the emitted light of the first liquid crystal layer 13 but There is a phase difference between the two directions. Similarly, after passing through the second liquid crystal layer 22, the emitted light becomes... There is a phase difference in polarization in the two directions. when At this time, the outgoing light is still linearly polarized, but its polarization direction is rotated by 90° compared to the incident light. In this case, the polarization transmission axis of the lower polarizer is parallel to it, allowing light to pass through. It is worth noting that in the above embodiment, n′1=n e This represents an ideal state. In reality, based on the PI boundary anchoring energy, the equivalent value of n′1 is greater than that of n. e Slightly smaller.

[0046] In the above embodiment, λ is taken as the median wavelength of visible light, 550 nm. From the above assumption, Δn1 - Δn2 = 0.098 is obtained. Substituting... The result is d = 2.76 μm.

[0047] In the above embodiments, the thickness of the first liquid crystal layer 13 along the vertical direction is the same as the thickness of the second liquid crystal layer 22 along the vertical direction, so as to meet the requirement of equivalent correction.

[0048] In the above embodiments, such as Figure 1-2 As shown, an upper glass substrate is disposed between the incident polarizer and the upper ITO layer, a middle glass substrate is disposed between the second ITO layer and the third PI layer, and a lower glass substrate is disposed between the fourth PI layer and the exiting polarizer. The upper glass substrate 5, the middle glass substrate 6, and the lower glass substrate 7 mentioned above have the same thickness, providing structural rigidity support for the entire VA panel.

[0049] Similarly, the first PI layer 12, the second PI layer 14, the third PI layer 21, and the fourth PI layer 23 have the same thickness along the vertical direction. They mainly serve as liquid crystal alignment films to control the initial alignment direction and pretilt angle of liquid crystal molecules in the first liquid crystal layer 13 and the second liquid crystal layer 22, so as to achieve the same friction angle in the first liquid crystal layer 13 and the second liquid crystal layer 22 and maintain uniformity.

[0050] It is worth noting that in the above embodiments, the first liquid crystal layer 13 and the second liquid crystal layer 22 are identical in terms of internal liquid crystal material, except that they have the same thickness.

[0051] Meanwhile, the inlet ports of the first liquid crystal layer 13 and the second liquid crystal layer 22 are on the same side and in the same position. Therefore, when filling the liquid crystal, it is ensured that the two liquid crystal layers of the first liquid crystal layer 13 and the second liquid crystal layer 22 are filled at the same time, thus ensuring the consistency of the product.

[0052] The above-disclosed content is only a preferred and feasible embodiment of the present utility model, and is not intended to limit the scope of the patent application of the present utility model. Therefore, all equivalent technical changes made using the contents of the present utility model specification and drawings are included in the scope of the patent application of the present utility model.

[0053] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

[0054] Although this application has been described by way of examples, those skilled in the art will know that this application has many modifications and variations without departing from the spirit of this application, and it is intended that the appended embodiments include these modifications and variations without departing from this application.

Claims

1. A liquid crystal panel for improving VA blackness, the liquid crystal panel having an incident end and an exit end disposed opposite to each other, characterized in that, The liquid crystal panel includes an incident polarizer, a first structural layer, a second structural layer, and an exit polarizer, which are stacked along the direction from the incident end to the exit end. The first structural layer includes a first ITO layer, a first PI layer, a first liquid crystal layer, a second PI layer, and a second ITO layer stacked along the incident end direction to the emission end direction; The second structural layer includes a third PI layer, a second liquid crystal layer, and a fourth PI layer stacked along the incident end direction to the exit end direction; The projection of the transmission axis of the incident polarizer and the liquid crystal friction direction onto the horizontal plane is at a 45-degree angle. The liquid crystals in the first liquid crystal layer and the liquid crystals in the second liquid crystal layer have the same angle of inclination relative to the vertical direction when no electricity is applied, and the angle between the projection of the inclination directions of the liquid crystals in the first liquid crystal layer and the liquid crystals in the second liquid crystal layer onto the horizontal plane is 90 degrees.

2. The liquid crystal panel for improving VA blackness according to claim 1, characterized in that: The thickness of the first liquid crystal layer along the vertical direction is the same as the thickness of the second liquid crystal layer along the vertical direction.

3. The liquid crystal panel for improving VA blackness according to claim 1, characterized in that: An upper glass substrate is disposed between the incident polarizer and the first ITO layer.

4. The liquid crystal panel for improving VA blackness according to claim 3, characterized in that: A middle glass substrate is disposed between the second ITO layer and the third PI layer.

5. The liquid crystal panel for improving VA blackness according to claim 4, characterized in that: A lower glass substrate is disposed between the fourth PI layer and the emitted polarizer.

6. The liquid crystal panel for improving VA blackness according to claim 5, characterized in that: The upper glass substrate, the middle glass substrate, and the lower glass substrate have the same thickness along the vertical direction.

7. The liquid crystal panel for improving VA blackness according to claim 1, characterized in that: The first PI layer, the second PI layer, the third PI layer, and the fourth PI layer have the same thickness in the vertical direction.

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