CN116819671A

CN116819671A - Phase delay structure and display device

Info

Publication number: CN116819671A
Application number: CN202310666433.XA
Authority: CN
Inventors: 章波; 张庆训; 陈东; 王建; 周志华; �田�浩
Original assignee: Chengdu Reboke Material Technology Co ltd
Current assignee: Chengdu Reboke Material Technology Co ltd
Priority date: 2023-06-06
Filing date: 2023-06-06
Publication date: 2023-09-29
Anticipated expiration: 2043-06-06
Also published as: CN116819671B

Abstract

The application discloses a phase delay structure and a display device, and relates to the technical field of display. A phase delay structure, comprising: a linear polarizing plate, a first phase difference film, and a second phase difference film, the first phase difference film and the second phase difference film being laminated, the linear polarizing plate being laminated on a side of the first phase difference film facing away from the second phase difference film; one of the first phase difference film and the second phase difference film has liquid crystal molecules aligned in parallel, and the other has liquid crystal molecules aligned obliquely; any one of the first phase difference film and the second phase difference film has a spiral structure. A display device includes the phase delay structure. The application at least can solve the problems of narrower wave domain of the antireflection film and the like in the related technology.

Description

Phase delay structure and display device

Technical Field

The application belongs to the technical field of display, and particularly relates to a phase delay structure and a display device.

Background

The OLED display screen industry is currently in a high-speed development period, the frequency of use is higher and higher, but the OLED is used as a reflective display device and can be influenced by external environment light, if a compensation film is not provided, the OLED reflects light like a mirror and reflects the external environment light into human eyes, so that the display contrast is reduced, dark state is caused, and the display effect is greatly influenced.

The antireflection film can reduce the interface reflection between media (the most basic reflection interface in the OLED display is the encapsulation interface under the OLED), and the harm of the interface reflection is the loss of light energy of the optical system and aggravates the stray light interference of the optical system.

Most of the anti-reflection films adopted by the traditional OLED are circular polaroids, so that the light efficiency can be improved, and adverse effects of external incident ambient light on the display effect can be reduced. However, such a compensation film has a problem of a narrower wave domain.

Disclosure of Invention

The embodiment of the application aims to provide a phase delay structure and a display device, which at least can solve the problems of narrower wave domain of an antireflection film and the like in the related art.

In order to solve the technical problems, the application is realized as follows:

the embodiment of the application provides a phase delay structure, which comprises the following components: a linear polarizing plate, a first phase difference film, and a second phase difference film, the first phase difference film and the second phase difference film being laminated, the linear polarizing plate being laminated on a side of the first phase difference film facing away from the second phase difference film;

one of the first phase difference film and the second phase difference film has liquid crystal molecules aligned in parallel, and the other has liquid crystal molecules aligned obliquely;

either one of the first phase difference film (120) and the second phase difference film has a spiral structure.

The embodiment of the application also provides a display device which comprises a display screen and the phase delay structure;

the display screen is arranged on one side of the phase delay structure, which is away from the light source.

In the embodiment of the application, the liquid crystal molecules which are arranged in parallel, the liquid crystal molecules which are arranged in an inclined way and the spiral structure are overlapped to form the composite film structure, and the composite film structure is used as the anti-reflection compensation film, so that the wave domain can be widened, a better integral black effect is realized, and the color cast is improved.

Drawings

Fig. 1 is a schematic view of the optical path principle of a related art liquid crystal display device;

FIG. 2 is a schematic diagram of a phase delay structure according to an embodiment of the present application;

fig. 3 is a schematic diagram of an optical path principle of a display device according to an embodiment of the present application;

FIG. 4 is a schematic view of the axial angles of the film layers according to an embodiment of the present application;

fig. 5 is a schematic structural view of the display device of example 1;

FIG. 6 is a schematic view of dark state light leakage outline of example 1;

fig. 7 is a schematic structural diagram of a display device of example 2;

FIG. 8 is a schematic view of dark state light leakage outline of example 2;

fig. 9 is a schematic structural view of a display device of example 3;

FIG. 10 is a schematic view of dark state light leakage outline of example 3;

fig. 11 is a schematic structural view of a display device of example 4;

FIG. 12 is a schematic view of dark state light leakage outline of example 4;

fig. 13 is a schematic structural view of a display device of example 5;

FIG. 14 is a schematic view of dark state light leakage outline of example 5;

fig. 15 is a schematic structural view of a display device of example 6;

fig. 16 is a schematic structural view of a display device of example 7;

fig. 17 is a schematic structural view of a display device of example 8;

fig. 18 is a schematic view showing the structure of a retardation film according to an embodiment of the present application.

Reference numerals illustrate:

a 100-phase delay structure;

110-linear polarizer;

120-a first phase difference film;

130-a second phase difference film; 131-a substrate; 132-an orientation layer; 133-a liquid crystal layer;

140-a third phase difference film;

200-a display screen;

300-light source.

Detailed Description

The following description of the embodiments of the present application will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are some, but not all embodiments of the application. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.

The terms first, second and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged, as appropriate, such that embodiments of the present application may be implemented in sequences other than those illustrated or described herein, and that the objects identified by "first," "second," etc. are generally of a type, and are not limited to the number of objects, such as the first object may be one or more. Furthermore, in the description and claims, "and/or" means at least one of the connected objects, and the character "/", generally means that the associated object is an "or" relationship.

The following describes embodiments of the present application in detail through specific embodiments and application scenarios thereof with reference to the accompanying drawings.

The OLED in the related art adopts a circular polaroid (linear polaroid +1/4λ) as the anti-reflection film, so that the light efficiency can be improved, and the influence of external incident ambient light on the display effect can be reduced. However, such a compensation film (linear polarizer+1/4λ compensation film) has a disadvantage of narrower wave domain. On the basis, the appearance again appearsA compensation film of the type "linear polarizer+1/2λ+1/4λ" is provided, which can achieve the effect of widening the wave domain, as shown in fig. 1. However, this type of compensation film needs to satisfy the condition 2θ due to the difference in alignment angle ₁ +45°＝θ ₂ Wherein θ ₁ An alignment angle of 1/2λ, θ ₂ An alignment angle of 1/4λ, and thus, different alignment angle processes are required for 1/2λ and 1/4λ, resulting in a complicated process.

Based on the above, embodiments of the present application provide a novel membrane structure in order to solve at least one of the above problems.

Referring to fig. 2 to 18, a phase delay structure 100 is disclosed in an embodiment of the present application, which can be applied in a display field, for example, in a display device, so as to improve visual effect. The disclosed retardation structure 100 includes a linear polarizer 110, a first retardation film 120, and a second retardation film 130. The first phase difference film 120 and the second phase difference film 130 are stacked, and the linear polarizer 110 is stacked on a side of the first phase difference film 120 facing away from the second phase difference film 130. Illustratively, the first phase difference film 120 and the second phase difference film 130 may be connected by a glue layer to ensure the connection firmness.

The linear polarizer 110 may be positioned at a side close to the external light source 300 for converting received light into linear polarized light; one of the first phase difference film 120 and the second phase difference film 130 has liquid crystal molecules aligned in parallel, that is, the liquid crystal molecules of one of the first phase difference film 120 and the second phase difference film 130 may have no tilt angle; the other has liquid crystal molecules aligned obliquely, i.e., the liquid crystal molecules of the other have a certain tilt angle.

In addition, either one of the first phase difference film 120 and the second phase difference film 130 has a spiral structure, and a wide wave reflection can be formed by a liquid crystal molecule having a spiral structure, and thus, an effect of widening a reflection spectrum can be achieved by adjusting a pitch.

In some embodiments, the first phase difference film 120 may have liquid crystal molecules aligned in parallel, and the second phase difference film 130 may have liquid crystal molecules aligned obliquely and have a spiral structure. With this arrangement, the linearly polarized light emitted from the linear polarizer 110 can be converted into elliptically polarized light by the first phase difference film 120, and the elliptically polarized light emitted from the first phase difference film 120 can be converted into circularly polarized light by the second phase difference film 130 under the action of the spiral structure, so as to satisfy a preset light conversion requirement.

In other embodiments, the phase delay structure may take other forms, as will be described in detail below.

The optical path principle of the phase delay structure 100 in the embodiment of the present application is:

the external light source 300 emits light to the linear polarizer 110, and the light is emitted through the linear polarizer 110 to form linear polarized light, and the linear polarized light sequentially passes through the first phase difference film 120 and the second phase difference film 130 and is converted into circularly polarized light, so that the circularly polarized light is reflected by other optical elements to be returned, thereby improving visual effect.

In some cases, the phase retardation structure 100 may be matched with the display screen 200 (e.g. OLED, etc.), specifically, the display screen 200 may be disposed on a side of the second phase difference film 130 away from the first phase difference film 120, so that left-handed (or right-handed) circularly polarized light is formed through the second phase difference film 130, and the left-handed (or right-handed) circularly polarized light is converted into right-handed (or left-handed) circularly polarized light by the reflection effect of the display screen 200, and the right-handed (or left-handed) circularly polarized light is converted into linear polarized light perpendicular to the linear polarized light when incident after sequentially passing through the second phase difference film 130 and the first phase difference film 120, so that the linear polarized light cannot pass through the linear polarizer 110, and the reflected light is blocked inside the linear polarizer 110 and cannot exit, so as to play an integral black effect.

Based on the above arrangement, in the embodiment of the application, the composite film structure is formed by superposing the liquid crystal molecules arranged in parallel, the liquid crystal molecules arranged in an inclined manner and the spiral structure, and the composite film structure is used as an antireflection compensation film, so that the wave domain can be widened, a better integral black effect is realized, and the color cast is improved.

In some embodiments, the helix angle of the helix is in the range of 80 ° to 89 °, including, for example, 80 °, 82 °, 84 °, 85 °, 87 °, 89 °, etc., although other degrees are possible and are not particularly limited herein. Here, the above spiral angle is understood as a twist angle.

The tilt angle of the liquid crystal molecules aligned at a tilt angle is in the range of 10 ° to 30 °, for example, including 10 °, 12 °, 15 °, 18 °, 20 °, 24 °, 25 °, 28 °, 30 °, and the like, but of course, other degrees are also possible, and the present application is not limited thereto. Here, the tilt angle is a pretilt angle of the liquid crystal molecules.

Here, the liquid crystal molecules of the first retardation film 120 may be arranged in a tilt angle ranging from 10 ° to 30 °, or the liquid crystal molecules of the second retardation film 130 may be arranged in a uniform tilt angle ranging from 10 ° to 30 °.

In some embodiments, a first preset shaft angle and a second preset shaft angle are formed between the shaft angle direction of the first phase difference film 120 and the second phase difference film 130 and the absorption shaft of the linear polarizer 110, respectively, and the first preset shaft angle is equal to the second preset shaft angle.

Wherein, the axis angle direction of the first phase difference film 120 forms a certain included angle with the absorption axis of the linear polarizer 110, so as to form a first preset axis angle, and the first preset axis angle of the second phase difference film 130 may be equal to the second preset axis angle of the first phase difference film 120; of course, the difference between the preset angle values can be also achieved so as to meet the actual working conditions.

Optionally, the respective angle ranges of the first preset shaft angle and the second preset shaft angle are-10 degrees to-20 degrees, etc. Here, the horizontal plane may be set as the initial position, and recorded as-10 ° to-20 ° according to the counterclockwise rotation; in contrast, the recording was 10 ° to 20 ° in terms of clockwise rotation.

Based on the above setting, under the condition that the angles of the first preset shaft angle and the second preset shaft angle are equal, the processing can be performed in a mode of simultaneous exposure alignment in the process treatment, only once exposure is performed, and the two layers simultaneously realize the same alignment angle, so that the processing efficiency can be improved.

In the embodiment of the present application, the first phase difference film 120 may be a phase difference film of a positive dispersion liquid crystal or a phase difference film of a negative dispersion liquid crystal.

Similarly, the second phase difference film 130 may be a phase difference film of a positive dispersion liquid crystal or a phase difference film of a negative dispersion liquid crystal.

In some embodiments, the thickness direction of the retardation structure 100 is a z-axis, the x-axis and the y-axis are orthogonal in a plane perpendicular to the thickness direction, and refractive indexes along the x, y, and z-axes are Nx, ny, and Nz, where the refractive indexes of the liquid crystals of the first phase difference film 120 and the second phase difference film 130 satisfy Nx > ny=nz. With this arrangement, light can be propagated in each of the retardation films along a predetermined path. Here, the first phase difference film 120 and the second phase difference film 130 may be a films, and the refractive indices thereof satisfy the same condition.

In some embodiments, the retardation structure 100 may further include a third retardation film 140, where the third retardation film 140 is stacked between the first retardation film 120 and the second retardation film 130, or where the third retardation film 140 is stacked on a side of the second retardation film 130 facing away from the first retardation film 120, or where the third retardation film 140 is stacked on a side of the first retardation film 120 facing away from the second retardation film 130. By arranging the third phase difference film 140, the third phase difference film 140 is matched with the first phase difference film 120 and the second phase difference film 130, and the light characteristics are adjusted, so that the actual working condition requirements are met.

The third retardation film 140 may be a retardation film of a positive dispersion liquid crystal or a retardation film of a negative dispersion liquid crystal.

In some embodiments, the thickness direction of the retardation structure 100 is a z-axis, the orthogonal x-axis and y-axis are taken in a plane perpendicular to the thickness direction, and refractive indexes of the liquid crystal of the third retardation film 140 along each of the x, y, and z-axes are Nx, ny, and Nz, where the refractive index of the liquid crystal of the third retardation film 140 satisfies nx=ny < Nz. With this arrangement, light can be made to travel along a predetermined path in the third phase difference film 140. Here, the third retardation film 140 may be a C film, and the refractive index thereof satisfies the condition, which is different from the condition satisfied by the refractive indices of the first retardation film 120 and the second retardation film 130.

Referring to fig. 18, in some embodiments, the first phase difference film 120 or the second phase difference film 130 may include a substrate 131 and a liquid crystal layer 133 disposed on a surface of the substrate 131, wherein the liquid crystal layer 133 is formed by mixing a laterally grafted surfactant and/or leveling agent containing two or more level differences with a photopolymerizable liquid crystal composition.

Specifically, the substrate 131 is subjected to surface treatment; a liquid crystal coating solution containing two or more different levels of laterally grafted surfactants and/or leveling agents and a photopolymerizable liquid crystal composition is applied to the substrate 131 to form a uniformly tilt-aligned liquid crystal layer 133.

Further, the first phase difference film 120 or the second phase difference film 130 further includes an alignment layer 132, the alignment layer 132 is formed on the surface of the substrate 131, the liquid crystal layer 133 is disposed on the surface of the alignment layer 132, and the alignment layer 132 contains at least one material selected from the group consisting of glassy polymers and a silica gel coupling agent.

Specifically, an alignment layer 132 is formed on a substrate 131, the alignment layer 132 containing at least one material selected from the group consisting of glassy polymers and a silica gel coupling agent; a liquid crystal coating solution containing two or more different levels of laterally grafted surfactants and/or leveling agents and a photopolymerizable liquid crystal composition is applied to the substrate 131 to form a uniformly tilt-aligned liquid crystal layer 133.

In other embodiments, the first phase difference film 120 or the second phase difference film 130 may include a substrate 131, an alignment layer 132, and a liquid crystal layer 133, wherein the alignment layer 132 is formed on the surface of the substrate 131, the liquid crystal layer 133 is disposed on the surface of the alignment layer 132, the alignment layer 132 contains at least one material selected from side chain type polymers, and the side chains of the side chain polymer materials have a height difference; the liquid crystal layer 133 is formed by mixing at least a surfactant containing lateral grafting of a height difference and a photopolymerizable liquid crystal composition.

Specifically, an alignment layer 132 may be formed on the substrate 131, the alignment layer 132 containing at least one material selected from side chain type high polymers, and the side chain of the side chain type high polymer material having a height difference; a liquid crystal coating solution containing a laterally grafted surfactant and a photopolymerizable liquid crystal composition of a height difference is applied to the substrate 131 to form a uniformly tilt-aligned liquid crystal layer 133.

Here, when the first phase difference film 120 has a liquid crystal molecule and a spiral structure uniformly and obliquely aligned, it may include a liquid crystal layer 133, an alignment layer 132, and a substrate 131 stacked in this order; when the second phase difference film 130 has a uniformly and obliquely aligned liquid crystal molecule and a spiral structure, it may include a liquid crystal layer 133, an alignment layer 132, and a substrate 131 stacked in this order.

In order to describe the retardation structure 100 in detail, various embodiments will be given below, in which the first retardation film 120 is defined as LC1, the second retardation film 130 is defined as LC2, the third retardation film 140 is defined as LC3, the linear polarizer 110 is POL, the display 200 is an OLED, and the light source 300 is disposed on the side of the linear polarizer 110, specifically:

example 1: NWD-A plate+NWD-A plate (uniformly inclined+spiral structure)

The first phase difference film 120 and the second phase difference film 130 are both phase difference films of positively dispersed liquid crystals, that is, the birefringence of the liquid crystals of each of the first phase difference film 120 and the second phase difference film 130 decreases with an increase in the wavelength of visible light; wherein the parameter Deltan of the refractive index anisotropy of the liquid crystal of each phase difference film ₁ ＝Δn ₂ The refractive index of the liquid crystal of each retardation film satisfies Nx > ny=nz, where Nx is the refractive index of the refractive film layer in the slow axis direction (i.e., the refractive index in the x direction), ny is the refractive index of the refractive film layer in the fast axis direction (i.e., the refractive index in the y direction), and Nz is the refractive index of the refractive film layer in the thickness direction (i.e., the refractive index in the z direction), as shown in fig. 5.

The first preset axial angle of the first phase difference film 120 ranges from-10 ° to-20 °;

the film thickness of the first phase difference film 120 ranges from 1 μm to 2 μm;

the second preset shaft angle of the second phase difference film 130 is the same as the first preset shaft angle of the first phase difference film 120 in the range of-10 to-20 degrees;

the second phase difference film 130 has a film thickness ranging from 1 μm to 2 μm;

the first phase difference film 120 and the second phase difference film 130 have the same preset axis angle, so that the same alignment angle (i.e., the preset axis angle) can be realized by exposing the two phase difference films only once.

The second phase difference film 130 has an arrangement in which liquid crystal molecules are uniformly inclined, and the inclination angle of the inclined liquid crystal molecules ranges from 10 ° to 30 ° (i.e., pretilt angle), and at the same time, the second phase difference film 130 has a spiral structure having a certain spiral angle ranging from 80 ° to 89 ° (i.e., twist angle).

The retardation of the first retardation film 120 may range from 160nm to 170nm;

the retardation of the second phase difference film 130 may range from 180nm to 190nm.

The above-described helix angle and target retardation are determined based on the alignment angle and the wavelength of light in a preset wavelength band.

Based on the above settings, the optical effects achieved are: the dark state light leakage effect is improved (the dark state light leakage distribution outline shown in fig. 6), and the color cast effect is improved; integral black effect: the maximum light leakage value under the full visual angle is 0.578, and the light leakage value at the positive visual angle is only 0.06; color cast effect: color cast effect: the polar angle of 60 degrees, the color cast change range under the omnibearing role is a: -0.6→4.1, b: -3.9→1.4.

In summary, in embodiment 1, the color shift of the large viewing angle can be further reduced, and the light leakage effect of the large viewing angle can be improved.

Example 2: RWD-A plate+RWD-A plate (uniformly inclined+spiral structure)

The first phase difference film 120 and the second phase difference film 130 are both phase difference films of inversely dispersed liquid crystals, that is, the birefringence of the liquid crystals of each of the first phase difference film 120 and the second phase difference film 130 increases with an increase in the wavelength of visible light; wherein the parameters of refractive index anisotropy of the liquid crystal of each retardation filmΔn ₁ ＝Δn ₂ The refractive index of the liquid crystal of each retardation film satisfies Nx > ny=nz, where Nx is the refractive index of the slow axis direction of the refractive film layer (i.e., the refractive index in the x direction), ny is the refractive index of the fast axis direction of the refractive film layer (i.e., the refractive index in the y direction), and Nz is the refractive index in the thickness direction of the refractive film layer (i.e., the refractive index in the z direction), as shown in fig. 7.

the film thickness of the first phase difference film 120 ranges from 3 μm to 4 μm;

the second phase difference film 130 has a film thickness ranging from 3 μm to 4 μm;

The retardation of the first retardation film 120 may range from 140nm to 150nm;

the retardation of the second phase difference film 130 may range from 160nm to 170nm.

Based on the above settings, the optical effects achieved are: the dark state light leakage effect is improved (the dark state light leakage distribution outline shown in fig. 8), and the color cast effect is improved; integral black effect: the maximum light leakage value under the full view angle is 0.492, and the light leakage value at the positive view angle is only 0.08; color cast effect: color cast effect: the polar angle of 60 degrees, the color cast change range under the omnibearing role is a: 0.07→4.3, b: 0.44→2.58.

In summary, in embodiment 2, the color shift of the large viewing angle can be further reduced, and the light leakage effect of the large viewing angle can be improved.

Example 3: NWD-A plate+RWD-A plate (uniformly inclined+spiral structure)

The first phase difference film 120 is a phase difference film of a positively dispersed liquid crystal, that is, a phase difference film whose birefringence of the liquid crystal decreases with an increase in the wavelength of visible light, and whose parameter Δn of the refractive index anisotropy of the liquid crystal ₁ =0.109, and the refractive index of the liquid crystal satisfies Nx > ny=nz, where Nx is the refractive index in the slow axis direction (i.e., the refractive index in the x direction) of the refractive film layer, ny is the refractive index in the fast axis direction (i.e., the refractive index in the y direction) of the refractive film layer, and Nz is the refractive index in the layer thickness direction (i.e., the refractive index in the z direction) of the refractive film layer, as shown in fig. 9.

the second phase difference film 130 is a phase difference film of an inversely dispersed liquid crystal, that is, a liquid crystal whose birefringence increases with an increase in the wavelength of visible light, and whose refractive index anisotropy parameter Δn ₂ =0.0465, and the refractive index of the liquid crystal satisfies Nx > ny=nz, where Nx is the refractive index in the slow axis direction of the refractive film layer (i.e., the refractive index in the x direction), ny is the refractive index in the fast axis direction of the refractive film layer (i.e., the refractive index in the y direction), and Nz is the refractive index in the layer thickness direction of the refractive film layer (i.e., the refractive index in the z direction), as shown in fig. 9.

the first phase difference film 120 and the second phase difference film 130 have the same preset axis angle, so that the same alignment angle (i.e. the preset axis angle) can be realized by exposing the two layers only once.

the retardation of the second phase difference film 130 may range from 150nm to 160nm.

Based on the above settings, the optical effects achieved are: the dark state light leakage effect is improved (the dark state light leakage distribution outline shown in fig. 10), and the color cast effect is improved; integral black effect: the maximum light leakage value under the full viewing angle is 0.62, and the light leakage value under the positive viewing angle is only 0.12.

In summary, embodiment 3 can further enhance the light leakage effect with a large viewing angle.

Example 4: NWD-a plate (uniform tilt) +nwd-Aplate (spiral structure)

The first phase difference film 120 and the second phase difference film 130 are both phase difference films of positively dispersed liquid crystals, that is, the birefringence of the liquid crystals of each of the first phase difference film 120 and the second phase difference film 130 decreases with an increase in the wavelength of visible light; wherein the parameter Deltan of the refractive index anisotropy of the liquid crystal of each phase difference film ₁ ＝Δn ₂ The refractive index of the liquid crystal of each retardation film satisfies Nx > ny=nz, where Nx is the refractive index of the refractive film layer in the slow axis direction (i.e., the refractive index in the x direction), ny is the refractive index of the refractive film layer in the fast axis direction (i.e., the refractive index in the y direction), and Nz is the refractive index of the refractive film layer in the thickness direction (i.e., the refractive index in the z direction), as shown in fig. 11.

The first preset axis angle of the first phase difference film 120 ranges from-10 ° to-20 °, and the liquid crystal molecules have a uniformly inclined arrangement, and the inclined angle of the inclined arrangement liquid crystal molecules ranges from 10 ° to 30 ° (i.e., pretilt angle);

the film thickness of the first phase difference film 120 ranges from 2 μm to 3 μm;

The second phase difference film 130 has a spiral structure having a certain spiral angle ranging from 80 ° to 89 ° (i.e., twist angle);

the retardation of the first retardation film 120 may range from 240nm to 250nm;

the retardation of the second phase difference film 130 may range from 210nm to 220nm.

As can be seen from the above, the maximum light leakage value at the full viewing angle of example 4 was 2.16, and the positive viewing angle light leakage value was 0.21, as shown in fig. 12.

Example 5: RWD-Aplate+C plate+RWD-A plate (uniformly inclined+spiral)

The first phase difference film 120 and the second phase difference film 130 are both phase difference films of inversely dispersed liquid crystals, that is, the birefringence of the liquid crystals of each of the first phase difference film 120 and the second phase difference film 130 increases with an increase in the wavelength of visible light; wherein the parameter Deltan of the refractive index anisotropy of the liquid crystal of each phase difference film ₁ ＝Δn ₂ The refractive index of the liquid crystal of each retardation film satisfies Nx > ny=nz, where Nx is the refractive index in the slow axis direction (i.e., the refractive index in the x direction) of the refractive film layer, ny is the refractive index in the fast axis direction (i.e., the refractive index in the y direction) of the refractive film layer, and Nz is the refractive index in the thickness direction of the refractive film layerRefractive index (i.e., refractive index in z direction), as shown in fig. 13.

the second phase difference film 130 has a second preset shaft angle in the range of-10 to-20 degrees;

the preset shaft angles between the first phase difference film 120 and the second phase difference film 130 are consistent, so that a simultaneous exposure alignment mode can be adopted in the process, and the two phase difference films can achieve the same alignment angle (i.e. the preset shaft angle) at the same time only by exposing once.

The third phase difference film 140 is also a phase difference film of an inversely dispersed liquid crystal, that is, a liquid crystal whose birefringence increases with an increase in the wavelength of visible light; wherein the refractive index anisotropy parameter Deltan of the liquid crystal ₃ The refractive index of the liquid crystal satisfies nx=ny < Nz, where Nx is the refractive index in the slow axis direction (i.e., the refractive index in the x direction) of the refractive film layer, ny is the refractive index in the fast axis direction (i.e., the refractive index in the y direction) of the refractive film layer, and Nz is the refractive index in the layer thickness direction (i.e., the refractive index in the z direction).

The thickness of the third phase difference film 140 is in the range of 0.1 μm to 1 μm.

The retardation Re of the first retardation film 120 may be in the range of 140nm to 150nm;

the retardation Re of the second phase difference film 130 may range from 160nm to 170nm;

the retardation Rth of the third phase difference film 140 may be in the range of 30nm to 40nm.

Compared with embodiment 2, the embodiment has a third phase difference film 140, i.e. C plate, which can improve the light leakage of large viewing angle, the maximum light leakage value of the full viewing angle is 0.26, and the positive viewing angle light leakage value is about 0; compared with embodiment 2, the dark state light leakage effect of this embodiment is significantly improved, as shown in fig. 14.

Example 6: RWD-Aplate+RWD-A plate (uniformly inclined+helical structure) +C plate

The first phase difference film 120 and the second phase difference film 130 are both phase difference films of inversely dispersed liquid crystals, that is, the birefringence of the liquid crystals of each of the first phase difference film 120 and the second phase difference film 130 increases with an increase in the wavelength of visible light; wherein the parameter Deltan of the refractive index anisotropy of the liquid crystal of each phase difference film ₁ ＝Δn ₂ =0.0465, and the refractive index of the liquid crystal of each phase difference film satisfies Nx > ny=nz, where Nx is the refractive index in the slow axis direction of the refractive film layer (i.e., the refractive index in the x direction), ny is the refractive index in the fast axis direction of the refractive film layer (i.e., the refractive index in the y direction), and Nz is the refractive index in the layer thickness direction of the refractive film layer (i.e., the refractive index in the z direction), as shown in fig. 15.

Compared with embodiment 2, the embodiment has a third phase difference film 140, i.e. C plate, which can improve the light leakage at a large viewing angle, and the maximum light leakage value at the full viewing angle is about 0.46, and compared with embodiment 2, the dark state light leakage effect of the embodiment is significantly improved, as shown in fig. 14.

Example 7: NWD-aplate+C plate+NWD-Aplate (uniformly inclined+spiral structure)

The first phase difference film 120 and the second phase difference film 130 are both phase difference films of positively dispersed liquid crystals, that is, the birefringence of the liquid crystals of each of the first phase difference film 120 and the second phase difference film 130 decreases with an increase in the wavelength of visible light; the refractive index of the liquid crystal of each retardation film satisfies Nx > ny=nz, where Nx is the refractive index of the refractive film layer in the slow axis direction (i.e., the refractive index in the x direction), ny is the refractive index of the refractive film layer in the fast axis direction (i.e., the refractive index in the y direction), and Nz is the refractive index of the refractive film layer in the thickness direction (i.e., the refractive index in the z direction), as shown in fig. 16.

The third phase difference film 140 is a phase difference film of positive dispersion liquid crystal, that is, the birefringence of the liquid crystal thereof decreases with an increase in the wavelength of visible light; the refractive index of the liquid crystal satisfies nx=ny < Nz, where Nx is the refractive index in the slow axis direction (i.e., the refractive index in the x direction) of the refractive film layer, ny is the refractive index in the fast axis direction (i.e., the refractive index in the y direction) of the refractive film layer, and Nz is the refractive index in the layer thickness direction (i.e., the refractive index in the z direction) of the refractive film layer.

Compared with embodiment 2, the embodiment has a third phase difference film 140, i.e. C plate, which can improve the light leakage at a large viewing angle, and the maximum light leakage value at the full viewing angle is about 0.26.

Example 8: NWD-A plate+NWD-Aplate (uniformly inclined+helical structure) +C plate

The first phase difference film 120 and the second phase difference film 130 are both phase difference films of positively dispersed liquid crystals, that is, the birefringence of the liquid crystals of each of the first phase difference film 120 and the second phase difference film 130 decreases with an increase in the wavelength of visible light; wherein, the refractive index of the liquid crystal of each phase difference film satisfies Nx > ny=nz, where Nx is the refractive index of the refractive film layer in the slow axis direction (i.e., the refractive index in the x direction), ny is the refractive index of the refractive film layer in the fast axis direction (i.e., the refractive index in the y direction), and Nz is the refractive index of the refractive film layer in the thickness direction (i.e., the refractive index in the z direction), as shown in fig. 17.

The third phase difference film 140 is a phase difference film of positive dispersion liquid crystal, that is, the birefringence of the liquid crystal thereof decreases with an increase in the wavelength of visible light; the refractive index of the liquid crystal satisfies nx=ny < Nz, where Nx is the refractive index in the slow axis direction (i.e., the refractive index in the x direction) of the refractive film layer, ny is the refractive index in the fast axis direction (i.e., the refractive index in the y direction) of the refractive film layer, and Nz is the refractive index in the thickness direction (i.e., the refractive index in the z direction) of the refractive film layer.

Compared with embodiment 2, the embodiment has a third phase difference film 140, i.e. C plate, which can improve the light leakage at a large viewing angle, and the maximum light leakage value at the full viewing angle is about 0.62.

In addition to the above manner, the embodiment of the present application may further include the following manner:

the double-layer A plate film layer structure is as follows:

POL+RWD-Aplate (uniform tilt) +RWD-Aplate (helical structure);

POL+NWD-A plate (uniform tilt) +RWD-A plate (helical structure);

POL+RWD-A plate (uniform tilt+helix) +RWD-A plate;

pol+nwd-a plate (uniform tilt+helical structure) +nwd-a plate, etc.

The double-layer A plate+C plate film layer structure is as follows:

pol+nwd-a plate+c plate+nwd-a plate (uniform tilt+helical structure);

POL+RWD-A plate+RWD-A plate (uniform tilt+helix) +C plate;

pol+nwd-a plate+nwd-a plate (uniform tilt+helical structure) +c plate;

POL+C plate+RWD-A plate (uniform tilt+helix);

pol+c plate+nwd-a plate (uniform tilt+helical structure);

pol+c plate+nwd-a plate (uniform tilt) +rwd-a plate (helical structure);

pol+c plate+rwd-a (uniform tilt) +nwd-a plate (helical structure), etc. In summary, in the embodiment of the application, the liquid crystal arrangement mode of the uniform inclination and spiral structure is adopted, so that the path of the light on the Ponga ball is better, and the wave domain can be widened;

the mode of uniform inclination and spiral structure ensures that the displayed light leakage is smaller, and a better integral black effect can be realized;

the mode of uniform inclination and spiral structure ensures that the displayed color difference is smaller, and the ideal hue effect can be achieved;

the alignment angles of the first phase difference film 120 and the second phase difference film 130 are consistent, and the simultaneous alignment of the two films can be realized through one exposure, so that the process is simplified;

in the mode of adding the double-layer A plate and the single-layer C plate, the C plate can compensate the phase difference in the thickness direction, the light leakage of a large visual angle can be improved, the color shift can be improved by matching the C plate with the A plate, and the effect of adjusting the hue can be realized by adjusting the retardation Rth value of the C plate.

The embodiments of the present application have been described above with reference to the accompanying drawings, but the present application is not limited to the above-described embodiments, which are merely illustrative and not restrictive, and many forms may be made by those having ordinary skill in the art without departing from the spirit of the present application and the scope of the claims, which are to be protected by the present application.

Claims

1. A phase delay structure, comprising: a linear polarizer (110), a first phase difference film (120), and a second phase difference film (130);

the first phase difference film (120) and the second phase difference film (130) are stacked, and the linear polarizer (110) is stacked on the side of the first phase difference film (120) facing away from the second phase difference film (130);

one of the first phase difference film (120) and the second phase difference film (130) has liquid crystal molecules aligned in parallel, and the other has liquid crystal molecules aligned obliquely;

either one of the first phase difference film (120) and the second phase difference film (130) has a spiral structure.

2. The phase delay structure of claim 1, wherein the helix angle of the helix is in the range of 80 ° to 89 °.

3. The retardation structure of claim 1, wherein the tilt angle of the tilt-aligned liquid crystal molecules ranges from 10 ° to 30 °.

4. The retardation structure according to claim 1, wherein the first retardation film (120) and the second retardation film (130) form a first predetermined shaft angle and a second predetermined shaft angle, respectively, between the shaft angle direction of each of the first retardation film and the second retardation film and the absorption shaft of the linear polarizer (110);

the first preset shaft angle is equal to the second preset shaft angle.

5. The phase delay structure of claim 4, wherein the first and second predetermined shaft angles are each in an angle range of-10 ° to-20 °.

6. The phase delay structure according to claim 1, wherein the first phase difference film (120) is a phase difference film of a positive dispersion liquid crystal or a phase difference film of a negative dispersion liquid crystal;

the second phase difference film (130) is a phase difference film of a positive dispersion liquid crystal or a phase difference film of a negative dispersion liquid crystal.

7. The retardation structure according to claim 1, wherein the retardation structure (100) has a thickness direction of z-axis, and has x-axis and y-axis orthogonal to each other in a plane perpendicular to the thickness direction, and refractive indexes along each of the x-, y-, and z-axes are Nx, ny-, nz;

the refractive index of each liquid crystal of the first phase difference film (120) and the second phase difference film (130) satisfies Nx > ny=nz.

8. The phase delay structure according to any one of claims 1 to 7, characterized in that the phase delay structure (100) further comprises a third phase difference film (140);

the third phase difference film (140) is stacked between the first phase difference film (120) and the second phase difference film (130),

alternatively, the third phase difference film (140) is stacked on a side of the second phase difference film (130) facing away from the first phase difference film (120);

alternatively, the third phase difference film (140) is stacked on a side of the first phase difference film (120) facing away from the second phase difference film (130).

9. The phase delay structure according to claim 8, wherein the third phase difference film (140) is a phase difference film of a positive-dispersion liquid crystal or a phase difference film of a negative-dispersion liquid crystal.

10. The retardation structure according to claim 8, wherein the retardation structure (100) has a thickness direction of z-axis, and has x-axis and y-axis orthogonal to each other in a plane perpendicular to the thickness direction, and refractive indices along the x, y, and z-axes are Nx, ny, and Nz;

the refractive index of the liquid crystal of the third phase difference film (140) satisfies nx=ny < Nz.

11. The phase retardation structure according to claim 1, wherein a first phase difference film (120) or the second phase difference film (130) includes a base material (131) and a liquid crystal layer (133) provided on a surface of the base material (131);

the liquid crystal layer (133) is formed by mixing at least a laterally grafted surfactant and/or a leveling agent containing two or more level differences with a photopolymerizable liquid crystal composition.

12. The retardation structure according to claim 11, wherein the first retardation film (120) or the second retardation film (130) further comprises an alignment layer (132), the alignment layer (132) is formed on the surface of the substrate (131), and the liquid crystal layer (133) is provided on the surface of the alignment layer (132);

the orientation layer (132) contains at least one material selected from the group consisting of glassy polymers and a silica gel bed coupling agent.

13. The phase retardation structure according to claim 1, wherein the first phase difference film (120) or the second phase difference film (130) includes a base material (131), an alignment layer (132), and a liquid crystal layer (133);

the alignment layer (132) is formed on the surface of the base material (131), and the liquid crystal layer (133) is provided on the surface of the alignment layer (132);

the orientation layer (132) contains at least one material selected from side chain type high polymer, and the side chain of the side chain high polymer material has a height difference;

the liquid crystal layer (133) is formed by mixing at least a surfactant containing lateral grafting of a height difference and a photopolymerizable liquid crystal composition.

14. A display device characterized by comprising a display screen (200) and a phase delay structure (100) as claimed in claims 1 to 13;

the display screen (200) is arranged on one side of the phase delay structure (100) away from the light source (300).