CN113504596B - Composite polarizer with wide viewing angle - Google Patents

Abstract

The invention is a composite polarizer with a wide viewing angle. The composition of the composite polarizer is: on the optical path, there are successively a first polarizing layer, an optically active layer, and a second polarizing layer; the angle between the optical rotation angle of the optically active layer and the transmission axes of the first and second polarizing layers The same or complementary; the angle between the transmission axes of the first and second polarizers ranges from 45 degrees to 135 degrees. In the composite polarizer, a composite polarizer with polarizing effect is formed through the arrangement of two polarizing layers in which the first polarizing layer, the optical active layer and the second polarizing layer are sequentially combined. Compared with the existing polarizer, the transmittance of the present invention is uniform at different azimuth angles, and can solve the brightness change caused by the use of the polarizer in the organic light-emitting display device.

Description

Composite polarizer with wide viewing angle

technical field

The invention relates to the technical field of polarizers, in particular to a composite polarizer with a wide viewing angle. The invention can be applied in display devices to reduce brightness variation in different viewing angles.

Background technique

Polarizer is a basic optical device that can be used to convert natural light into polarized light, and can also be used to selectively transmit polarized light of different polarization states. Polarizers are widely used in many display devices including liquid crystal displays, organic light-emitting displays, and the like. In a liquid crystal display, the polarizer and the liquid crystal layer together constitute an optical switch that realizes the display function. In active light-emitting display devices such as organic light-emitting displays, polarizers are used to reduce the reflection of ambient light. In 3D displays, polarizers are used to generate polarized light. The performance of the polarizer directly affects the display effect of the display device. Existing polarizers mainly include metal polarizers, iodine-based polarizers, dye-based polarizers and polyethylene polarizers. For any type of polarizer, the realization of its polarizing effect depends on the alignment of molecules/molecular groups with optical anisotropy. Taking the iodine-based polarizer commonly used in display devices as an example, its polarizing effect is realized by the iodine ions aligned on the polyvinyl alcohol film. When light passes through the polarizer, the linearly polarized light whose polarization direction is along the iodide ion arrangement direction is absorbed, and the outgoing light is linearly polarized light. In a polarizer, the polarization direction of the absorbed polarized light is called the absorption axis direction, and the polarization direction of the outgoing light is called the transmission axis direction, and the absorption axis is perpendicular to the transmission axis direction.

Since the function of the polarizer comes from the anisotropic structure, a single polarizer has different transmittance under different viewing angles. When the incident angle reaches 45°, the transmittance difference of the traditional polarizer at different azimuth angles is about 20%. And when the incident angle increases to 75°, the transmittance difference of different azimuth angles is as high as 60%. In organic light-emitting display devices, the viewing angle characteristics of polarizers are intuitively reflected. Only one piece of circular polarizer is used in the organic light-emitting display device to reduce reflection, so the viewing angle characteristics of the polarizer greatly affect the display brightness under different viewing angles. Even though the luminous uniformity of the light-emitting components in the organic light-emitting display device is better than that of the backlight in the liquid crystal display device, the display brightness uniformity of the organic light-emitting display device at different viewing angles is still worse than that of the liquid crystal display device. The uneven transmittance of the polarizer under different viewing angles greatly affects the display effect of the display device. At present, research on the viewing angle of polarizers is mainly focused on optimizing the contrast of two crossed polarizers at different viewing angles. By adding a compensation film to the structure of the polarizer, the light leakage of the two crossed polarizers at an oblique viewing angle can be reduced, thereby increasing the contrast at an oblique viewing angle. For example, the contrast ratio at oblique viewing angles can be increased by adding a compensation film structure (Chinese invention patent CN202010253314.8 with the title of the invention "a polarizer for a wide viewing angle liquid crystal display"). Essentially, the problem of uneven transmittance of existing polarizers under different viewing angles is due to their structural characteristics. The polarizing layer that plays a polarizing effect in polarized light can be regarded as a two-dimensional plane composed of multiple one-dimensional structures, while observation under different viewing angles is carried out in a three-dimensional space. The structure of the polarizing layer is different under different viewing angles. showed significant differences. When the polar angle is the same, the projections of the light absorption axis formed by iodide ions and the light transmission axis of the polarizing layer at different azimuth angles are completely different. Adding additional structures such as compensation films to the polarizer cannot change the structural characteristics of the polarizing layer in the polarizer. The structure of the polarizing layer of the existing polarizer is still two-dimensional, so there is still the problem of uneven transmittance under different viewing angles. . So far, the transmittance of polarizers under different viewing angles is still uneven. In order to solve the problem of uneven transmittance of the polarizer at different viewing angles, it is necessary to make the projection of the transmission axis in the polarizing layer consistent at different viewing angles, which means that the polarizing layer needs to contain Symmetrical three-dimensional structures. However, the anisotropic two-dimensional structure of the polarizing layer is the basis for realizing the polarizing effect, and changes to the structure of the polarizing layer will greatly affect the polarizing effect of the polarizing layer. Designing a polarizer with a symmetrical three-dimensional structure and ideal polarizing effect faces many problems. On the one hand, it is necessary to break the structural limitations of the polarizer itself and transform the two-dimensional structure into a three-dimensional structure. Two-dimensional anisotropic structures simultaneously achieve symmetry in three-dimensional space. A wide viewing angle polarizer with uniform transmittance under different viewing angles is a great challenge while having great application prospects.

Contents of the invention

Aiming at the problem of uneven transmittance of the existing polarizer under different viewing angles, the invention proposes a composite polarizer with a wide viewing angle. The composite polarizer is composed of a first polarizer layer, an optical active layer and a second polarizer layer in sequence, and forms a composite polarizer with polarizing effect. In the present invention, the two polarizing layers are in different planes and the directions of their light transmission axes are different. The projections of the three-dimensional structures formed by the light transmission axes in the two polarizing layers under different viewing angles have strong consistency. The design of the optically active layer The influence of the structure change of the polarizing layer on the polarizing effect is eliminated, so the present invention has uniform transmittance under different viewing angles and also has an ideal polarizing effect. Compared with the existing polarizer, the transmittance of the present invention is uniform at different azimuth angles, and can be applied in organic light-emitting display devices to reduce brightness variation under different viewing angles.

Technical scheme of the present invention is:

A composite polarizer with a wide viewing angle is characterized in that the polarizer is composed of: a first polarizing layer, an optically active layer, and a second polarizing layer on the optical path;

The range of the included angle between the transmission axes of the first and second polarizing layers is 45 degrees to 135 degrees;

The optical rotation angle of the optical active layer is the same as or complementary to the angle between the transmission axes of the first and second polarizing layers.

Optionally, the optically active layer is a liquid crystal optically active layer or a combined wave plate optically active layer.

The polarizing layer includes but is not limited to absorbing polarizers, polarization selectors, metal wire grids or reflective polarizers;

The constituent material of the liquid crystal optically active layer is a liquid crystal material or a liquid crystal polymer material.

The twist angle of the liquid crystal molecules in the liquid crystal optical active layer is the same as or complementary to the angle between the transmission axes of the first and second polarizing layers.

The optical active layer of the combined wave plate is composed of 2-20 wave plates, and the direction of the slow axis of the wave plates is arranged in a left-handed or right-handed twist.

The included angle between the slow axes of adjacent wave plates in the combined wave plate optical active layer is less than or equal to 60°.

Substantive features of the present invention are:

The existing polarizer only contains one layer of polarizing layer, and the projection of its transmission axis is obviously different under different viewing angles, so the transmittance under different viewing angles has obvious differences. When the incident angle is 75°, different azimuth angles The transmittance difference is as high as 60%. In the wide viewing angle composite polarizer proposed by the present invention, two polarizing layers with different light transmission axis directions are innovatively used, and an optical active layer is arranged in it. The three-dimensional structure formed by the light transmission axes of the two polarizing layers in the polarizer is different. The projection under viewing angles is consistent, so the present invention has uniform transmittance under different viewing angles.

The beneficial effects of the present invention are:

The composite polarizer with a wide viewing angle provided by the present invention has more uniform transmittance under different viewing angles, and the variation of the transmittance under different azimuth angles is only one-fifth of that of the traditional polarizer. When the present invention is applied to display devices such as organic light-emitting display devices, the luminance variation of the display device at different azimuth angles can be reduced by 80%.

Description of drawings

Figure 1 is a schematic diagram of a reference system for observing the transmittance of a polarizer at different viewing angles;

Fig. 2 is the schematic cross-sectional structure diagram of the composite polarizer with wide view angle proposed by the present invention;

Fig. 3 is a schematic cross-sectional structure diagram of a wide viewing angle composite polarizer provided in Embodiment 1 of the present invention;

FIG. 4 is a schematic cross-sectional structure diagram of the liquid crystal layer in FIG. 3;

Figure 5 is a schematic diagram of the direction of the light transmission axis on both sides of the composite polarizer with a wide viewing angle;

Fig. 6 is a schematic diagram of polarization state change when incident light passes through a wide viewing angle composite polarizer;

Fig. 7 is a schematic diagram of the transmittance variation of a traditional iodine-based polarizer under different viewing angles;

Fig. 8 is a schematic diagram of the transmittance variation of the wide viewing angle composite polarizer provided in Example 1 of the present invention under different viewing angles;

Fig. 9 shows the brightness variation of an organic light-emitting display device using a traditional iodine-based polarizer under different viewing angles;

Fig. 10 shows the brightness variation of the organic light-emitting display device using the wide viewing angle composite polarizer provided in Example 1 of the present invention under different viewing angles;

11 is a schematic cross-sectional structure diagram of a wide viewing angle composite polarizer provided in Embodiment 2 of the present invention;

Fig. 12 is the structural formula of three kinds of monomers forming the liquid crystal polymer optically active layer in Fig. 9;

Fig. 13 is a schematic diagram of the transmittance variation of the wide viewing angle composite polarizer provided in Example 2 of the present invention under different viewing angles;

Fig. 14 is a schematic cross-sectional structure diagram of a wide viewing angle composite polarizer provided in Embodiment 3 of the present invention;

FIG. 15 is a schematic diagram of the transmittance variation of the wide viewing angle composite polarizer provided in Example 3 of the present invention under different viewing angles.

Detailed ways

The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, but not to limit the present invention. In addition, it should be noted that, for the convenience of description, only some structures related to the present invention are shown in the drawings but not all structures.

Example 1

。在XY平面内，X轴方向规定为0°方向。Figure 1 is a schematic diagram of the reference system for observing the transmittance of polarizers at different viewing angles. Referring to Figure 1, the angle between the line of sight and the Z axis is the polar angle θ, and the angle between the projection of the line of sight on the XY plane and the X axis is the azimuth angle

. In the XY plane, the X-axis direction is defined as the 0° direction.

FIG. 2 is a schematic cross-sectional structure diagram of a wide viewing angle composite polarizer proposed by the present invention, which includes a first polarizing layer 10 , an optical active layer 30 and a second polarizing layer 20 .

Fig. 3 is a schematic cross-sectional structure diagram of a wide viewing angle composite polarizer provided in Example 1 of the present invention, Fig. 4 is a schematic cross-sectional structure schematic diagram of the liquid crystal layer in Fig. 3, and Fig. 5 is the light transmission axis direction on both sides of the wide viewing angle composite polarizer , Fig. 6 is a schematic diagram of the polarization state change when the incident light passes through the composite polarizer with a wide viewing angle. Combining Fig. 3, Fig. 4, Fig. 5 and Fig. 6, the extension direction of the double arrow in Fig. 5 indicates the transmission on both sides of the composite polarizer with a wide viewing angle. the direction of the optical axis. The light transmission axes on both sides of the wide viewing angle compound polarizer are along the 0° direction and the 90° direction respectively.

The composition of the composite wide viewing angle polarizer comprises from bottom to top a first polarizer layer 10, a liquid crystal optically active layer 30 and a second polarizer layer 20, wherein the first polarizer layer 10 and the second polarizer layer 20 are iodine-based polarizers , the liquid crystal optically active layer 30 is a liquid crystal cell;

The first and second polarizing layers are iodine-based polarizers.

The thickness of the first and second polarizing layers is 80 microns.

The liquid crystal optically active layer 30 sequentially includes a lower glass substrate 301, a lower alignment layer 302, a liquid crystal layer 303, an upper alignment layer 304, and an upper glass substrate 305 from bottom to top;

The light transmission axis direction of the first polarizing layer 10 is along the 0° direction, the light transmission axis of the second polarizing layer 20 is along the 90° direction, and the liquid crystal layer 303 includes a first surface 3031 near the first polarizing layer side and a first surface 3031 near the second polarizing layer. The second surface 3032 on the layer side.

As shown in Figure 4, the director of the liquid crystal molecules on the first surface 3031 (i.e. the surface near the first polarizing layer in the liquid crystal layer) is along the 0° direction, and the second surface 3032 (i.e. the surface near the second polarizing layer in the liquid crystal layer) The director of the liquid crystal molecules is along the 90° direction. Along the direction perpendicular to the liquid crystal layer 303 , the directors of the liquid crystal molecules in the liquid crystal layer 303 are uniformly twisted by 90°.

In the wide viewing angle composite polarizer provided in this embodiment. The incident light I is converted into linearly polarized light P1 whose polarization direction is along the direction of 0° after passing through the first polarizing layer 10; when the linearly polarized light P1 passes through the liquid crystal optical rotation layer 30, the polarization direction is rotated by 90°, and the liquid crystal optical rotation layer cannot realize ideal Polarization rotation, the outgoing light P2 passing through the liquid crystal optical rotation layer 30 is approximately linearly polarized light whose polarization direction is along the 90° direction; P2 becomes linearly polarized light P3 whose polarization direction is along the 90° direction after passing through the second polarizing layer 20 . When the viewing angle is inclined, the transmittance of the composite polarizer with a wide viewing angle proposed by the present invention is jointly determined by the first and second polarizing layers. The transmission axes of the first and second polarizing layers are perpendicular to each other, so the transmittances of the two polarizing layers at different viewing angles can compensate each other, thereby obtaining uniform transmittance at different viewing angles.

，纵坐标为透过率。图7中的6条曲线分别对应6个不同的极角：0°、15°、30°、45°、60°和75°。即分别在θ＝0°、θ＝15°、θ＝30°、θ＝45°、θ＝60°和θ＝75°时，测量了现有偏光片对自然光的透过率。随着极角的增大，偏光片在不同方位角下的透过率表现出了明显的差异。当极角为45°时，不同方位角的透过率差值为16％。当极角为60°时，不同方位角的透过率差值为32％。当极角为75°时，不同方位角的透过率差值为60％。FIG. 7 is a schematic diagram of the transmittance change of a traditional iodine-based polarizer under different viewing angles. When observed, the transmission axis of the polarizer is along a 90° direction. Referring to Figure 1 and Figure 7, the abscissa is the azimuth

, and the ordinate is the transmittance. The six curves in Figure 7 correspond to six different polar angles: 0°, 15°, 30°, 45°, 60° and 75°. That is, when θ=0°, θ=15°, θ=30°, θ=45°, θ=60° and θ=75°, the transmittance of the existing polarizer to natural light was measured. As the polar angle increases, the transmittance of the polarizer shows obvious differences at different azimuth angles. When the polar angle is 45°, the transmittance difference of different azimuth angles is 16%. When the polar angle is 60°, the transmittance difference of different azimuth angles is 32%. When the polar angle is 75°, the transmittance difference at different azimuth angles is 60%.

，纵坐标为透过率。图8中的6条曲线分别对应6个不同的极角：0°、15°、30°、45°、60°和75°。即分别在θ＝0°、θ＝15°、θ＝30°、θ＝45°、θ＝60°和θ＝75°时，测量了实施例1对自然光的透过率。这里使用光谱仪测试了偏光片在不同视角下对于波长为550nm的单色光的透过率。在任一极角下，实施例1在不同方位角下的透光率没有明显的变化。当极角为45°时，不同方位角的透过率差值为0.6％。当极角为60°时，不同方位角的透过率差值为3.7％。当极角为75°时，不同方位角的透过率差值为12.5％。相对于传统的偏光片，本发明提出的宽视角复合偏光片在不同视角下的透过率更加均匀。8 is a schematic diagram of the transmittance variation of the wide viewing angle composite polarizer provided in Example 1 of the present invention under different viewing angles. The light transmission axis of the polarizing layer on the incident side is along the 90° direction during observation. Referring to Figure 1 and Figure 8, the abscissa is the azimuth

, and the ordinate is the transmittance. The six curves in Figure 8 correspond to six different polar angles: 0°, 15°, 30°, 45°, 60° and 75°. That is, when θ=0°, θ=15°, θ=30°, θ=45°, θ=60° and θ=75°, the transmittance of Example 1 to natural light was measured. Here, a spectrometer is used to test the transmittance of the polarizer for monochromatic light with a wavelength of 550nm under different viewing angles. At any polar angle, the light transmittance of Example 1 has no obvious change under different azimuth angles. When the polar angle is 45°, the transmittance difference between different azimuth angles is 0.6%. When the polar angle is 60°, the transmittance difference of different azimuth angles is 3.7%. When the polar angle is 75°, the transmittance difference of different azimuth angles is 12.5%. Compared with the traditional polarizer, the wide viewing angle composite polarizer proposed by the present invention has more uniform transmittance under different viewing angles.

Figure 9 shows the luminance changes of an organic light-emitting display device using a traditional iodine-based polarizer at different viewing angles, and Figure 10 shows the brightness of an organic light-emitting display device using the wide viewing angle composite polarizer provided in Example 1 of the present invention at different viewing angles Variation, which specifies a brightness of 1 at a normal viewing angle. Referring to Figure 9 and Figure 10, when the viewing angle is inclined, the brightness of the organic light-emitting display device using the traditional iodine-based polarizer changes significantly at different azimuth angles. The luminance variation of the light-emitting display device under different azimuth angles is significantly reduced. At a polar angle of 75 degrees, the brightness change of the organic light-emitting display device using the traditional iodine-based polarizer at different azimuth angles is 60%, and the organic light-emitting display device using the wide viewing angle composite polarizer provided in Example 1 of the present invention has a The brightness variation under different azimuth angles is only 12.5%.

Example 2

Figure 11 is a schematic cross-sectional structure diagram of a wide viewing angle composite polarizer provided in Example 2 of the present invention, and Figure 12 is the structural formula of the three monomers forming the optically active layer of the liquid crystal polymer in Figure 11, referring to Figure 11 and Figure 12, composite The wide viewing angle polarizer includes a first polarizing layer 10, a liquid crystal optically active layer 40 and a second polarizing layer 20, wherein the first polarizing layer 10 and the second polarizing layer 20 are iodine polarizers, and the liquid crystal optically active layer 40 is made of HCM-021, A liquid crystal polymer composed of three monomers, HCM-020 and HCM-009 (the monomers were purchased from Jiangsu Hecheng Display Technology Co., Ltd.). The liquid crystal optical active layer 40 includes a lower substrate 401 and a liquid crystal polymer layer 402, wherein the thickness of the lower substrate 401 is 1 micron, and the thickness of the liquid crystal polymer layer 402 is 5 microns. The light transmission axis direction of the first polarizing layer 10 is along the 0° direction, the light transmission axis of the second polarizing layer 20 is along the 90° direction, and the liquid crystal polymer layer 402 includes a first surface 4021 near the first polarizing layer side and a first surface 4021 near the second polarizing layer. The second surface 4022 on the side of the two polarizing layers. The director of the liquid crystal molecules on the first surface 4021 is along the direction of 90°, and the director of the liquid crystal molecules on the second surface 4022 is along the direction of 0°. Along the direction perpendicular to the liquid crystal polymer layer 402, the directors of the liquid crystal molecules in the liquid crystal polymer layer 402 are uniformly twisted by -90°. In embodiment 1, the director direction of the liquid crystal molecules on the surface close to the polarizing layer is parallel to the light transmission axis direction of the polarizer; Axes are perpendicular to each other. At this time, the optical activity of the liquid crystal optically active layer remains unchanged, and Example 2 exhibits characteristics similar to those of Example 1.

，纵坐标为透过率。图13中的6条曲线分别对应6个不同的极角：0°、15°、30°、45°、60°和75°。即分别在θ＝0°、θ＝15°、θ＝30°、θ＝45°、θ＝60°和θ＝75°时，测量了实施例2对自然光的透过率。在任一极角下，实施例2在不同方位角下的透光率没有明显的变化。相对于传统的偏光片，本发明提出的宽视角复合偏光片在不同视角下的透过率更加均匀。FIG. 13 is a schematic diagram of the transmittance variation of the wide viewing angle composite polarizer provided in Example 2 of the present invention under different viewing angles. When observed, the light transmission axis of the polarizing layer on the incident side is along the 90° direction. Referring to Figure 1 and Figure 13, the abscissa is the azimuth

, and the ordinate is the transmittance. The six curves in Figure 13 correspond to six different polar angles: 0°, 15°, 30°, 45°, 60° and 75°. That is, when θ=0°, θ=15°, θ=30°, θ=45°, θ=60° and θ=75°, the transmittance of Example 2 to natural light was measured. At any polar angle, the light transmittance of Example 2 has no obvious change under different azimuth angles. Compared with the traditional polarizer, the wide viewing angle composite polarizer proposed by the present invention has more uniform transmittance under different viewing angles.

The difference between this embodiment and Embodiment 1 is reflected in two aspects. First, the material of the liquid crystal optically active layer in embodiment 2 is liquid crystal polymer, and the material of the liquid crystal optically active layer in embodiment 1 is liquid crystal. Second, the director of the liquid crystal molecules at the surface of the liquid crystal layer in embodiment 2 is perpendicular to the direction of the transmission axis of the polarizer on the same side, and the director of the molecules at the surface of the liquid crystal layer in embodiment 1 is perpendicular to the direction of the transmission axis of the polarizer on the same side parallel. The final result is similar when the liquid crystal optical active layer is composed of liquid crystal or liquid crystal polymer material, and the final result is similar when the director of the liquid crystal molecules on the surface of the liquid crystal layer is perpendicular to or parallel to the transmission axis of the polarizer on the same side. Through two different embodiments, it is illustrated that similar effects can be achieved by using different materials and different structures when meeting the requirements of the present invention.

Example 3

Fig. 14 is a schematic cross-sectional structure diagram of a wide viewing angle composite polarizer provided in Embodiment 3 of the present invention. The composite wide viewing angle polarizer includes a first polarizing layer 10, a combined wave plate optical rotation layer 50 and a second polarizing layer 20, wherein the first The polarizing layer 10 and the second polarizing layer 20 are iodine-based polarizers, the combined wave plate optically active layer 50 is a multi-layer combined wave plate, and the wave plate is an R138 polymer wave plate (purchased from Sanlipu Optoelectronics Technology Co., Ltd.). The combined wave plate optical active layer includes a first wave plate 501, a second wave plate 502, a third wave plate 503, a fourth wave plate 504, a fifth wave plate 505, a sixth wave plate 506, and a seventh wave plate of the same material and thickness. wave plate 507 , eighth wave plate 508 and ninth wave plate 509 . The light transmission axis direction of the first polarizing layer 10 is along the 0° direction, the light transmission axis direction of the second polarizing layer 20 is along the 90° direction, and the slow axis directions of the nine wave plates are 0°, 10°, 20°, and 30° in turn. , 40°, 50°, 60°, 70°, 80°, and 90°, the angle between the slow axes of adjacent wave plates is 10°, and the slow axes of the wave plates are right-handed. The combined wave plate optical rotation layer 50 can play an optical rotation function similar to that of the twisted nematic liquid crystal layer, and Example 3 exhibits similar characteristics to Example 1.

，纵坐标为透过率。图15中的6条曲线分别对应6个不同的极角：0°、15°、30°、45°、60°和75°。即分别在θ＝0°、θ＝15°、θ＝30°、θ＝45°、θ＝60°和θ＝75°时，测量了实施例3对自然光的透过率。在任一极角下，实施例3在不同方位角下的透光率没有明显的变化。相对于传统的偏光片，本发明提出的宽视角复合偏光片在不同视角下的透过率更加均匀。Fig. 15 is a schematic diagram of the transmittance variation of the wide viewing angle composite polarizer provided in Example 3 of the present invention under different viewing angles, and the light transmission axis of the polarizing layer on the incident side is along the 90° direction during observation. Referring to Figure 1 and Figure 15, the abscissa is the azimuth

, and the ordinate is the transmittance. The 6 curves in Figure 15 correspond to 6 different polar angles: 0°, 15°, 30°, 45°, 60° and 75°. That is, when θ=0°, θ=15°, θ=30°, θ=45°, θ=60° and θ=75°, the transmittance of Example 3 to natural light was measured. At any polar angle, the light transmittance of Example 3 has no obvious change under different azimuth angles. Compared with the traditional polarizer, the wide viewing angle composite polarizer proposed by the present invention has more uniform transmittance under different viewing angles.

Note that the above are only preferred embodiments of the present invention and applied technical principles. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described here, and various obvious changes, readjustments, mutual combinations and substitutions can be made by those skilled in the art without departing from the protection scope of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and can also include more other equivalent embodiments without departing from the concept of the present invention, and the present invention The scope is determined by the scope of the appended claims.

Matters not covered in the present invention are known technologies.

Claims (2)

1. A wide visual angle composite polarizer is characterized in that the polarizer comprises a first polarizing layer, an optical rotation layer and a second polarizing layer in sequence on an optical path;

the included angle between the light transmission axes of the first polarizing layer and the second polarizing layer ranges from 45 degrees to 135 degrees;

the optical rotation angle of the optical rotation layer is the same as or complementary to the included angle between the light transmission axes of the first and second polarizing layers;

the optical rotation layer is a liquid crystal optical rotation layer or a combined wave plate optical rotation layer;

the twist angle of liquid crystal molecules in the liquid crystal optical rotation layer is the same as or complementary with the included angle between the light transmission axes of the first polarizing layer and the second polarizing layer;

the combined wave plate rotating layer consists of 2-20 wave plates, and the slow axis direction of the wave plates is in left-handed or right-handed twisted arrangement;

the included angle between the slow axes of the adjacent wave plates in the optical rotation layer of the combined wave plate is less than or equal to 60 degrees.

2. The wide viewing angle composite polarizer according to claim 1, wherein the constituent material of said liquid crystal polarizing layer is a liquid crystal material or a liquid crystal polymer material.

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