Anti-peeping module and display device

Abstract

The invention provides a peep-proof module and a display device. The peep-proof module comprises an anisotropic diffusion film, an electric control phase retarder and a first polaroid. The anisotropic diffusion film comprises a base material, a plurality of first optical microstructures and a first liquid crystal layer. The plurality of first optical microstructures is disposed on the placement surface of the substrate. The first optical microstructures are arranged in a first direction and extend in a second direction. The first liquid crystal layer directly covers the first optical microstructures. The orthographic projection of the optical axis of the first liquid crystal layer on the setting surface is parallel to the second direction. The first liquid crystal layer has a first refractive index and a second refractive index which are different in the first direction and the second direction respectively. The difference value between one of the first refractive index and the second refractive index and the refractive index of the first optical microstructure is larger than or equal to 0.05. The axial direction of the first absorption axis of the first polaroid is parallel or perpendicular to the second direction. The peep-proof module and the display device provided by the invention have excellent display effects when being operated in the sharing mode and the peep-proof mode.

Description

Technical Field

[0001] The present invention relates to an anti-peeping display technology, and particularly to an anti-peeping module and a display device. Background Art

[0002] Generally speaking, in order to enable multiple viewers to watch together, a display device usually has a wide viewing angle display effect. However, in some cases or occasions, such as browsing private web pages, confidential information, or entering passwords in public places, the wide viewing angle display effect is likely to cause the screen image to be peeped by others and result in the leakage of confidential information. To achieve an anti-peeping effect, one approach is to place a light control film (LCF) in front of the display panel to filter out light at large angles. Considering operation convenience, another approach is to add an electrically controlled diffuser to achieve an electrically controllable switched anti-peeping display. However, the diffusion effect of the electrically controlled diffuser is omnidirectional, making it difficult to improve the display brightness within a specific viewing angle range (such as the front viewing angle) when the display device operates in the sharing display mode.

[0003] There is also an approach that uses a combination of an additional electrically controlled liquid crystal cell and a polarizer to electrically control the filtering of light in the anti-peeping axial direction. Although the added electrically controlled liquid crystal cell can only limitedly reduce the display brightness in the anti-peeping direction, the anti-peeping effect of the display device is limited. Therefore, how to develop a display device with extremely convenient viewing angle switching and excellent anti-peeping effect has become an important issue for related manufacturers.

[0004] The "Background Art" paragraph is only used to help understand the content of the present invention. Therefore, the content disclosed in the "Background Art" paragraph may include some known technologies that are not known to those skilled in the art of the relevant technical field. The content disclosed in the "Background Art" paragraph does not represent that the content or the problems to be solved by one or more embodiments of the present invention have been known or recognized by those skilled in the art before the application of the present invention. Summary of the Invention

[0005] The present invention provides an anti-peeping module with better anti-peeping effect.

[0006] The present invention provides a display device with excellent display effects when operating in the sharing mode and the anti-peeping mode.

[0007] Other objects and advantages of the present invention can be further understood from the technical features disclosed in the present invention.

[0008] To achieve one or part or all of the above purposes or other purposes, an embodiment of the present invention provides an anti-peeping module. The anti-peeping module includes a diffractive film, an electrically controlled phase retarder, and a first polarizer. The diffractive film includes a substrate, a plurality of first optical microstructures, and a first liquid crystal layer. The substrate has a set surface, and the plurality of first optical microstructures are disposed on the set surface of the substrate. These first optical microstructures are arranged along a first direction and extend in a second direction. The first direction and the second direction intersect each other, and the first direction and the second direction are parallel to the set surface. The first liquid crystal layer is disposed on the substrate and directly covers these first optical microstructures. The positive projection of the optical axis of the first liquid crystal layer on the set surface is parallel to the second direction. The first liquid crystal layer has different first and second refractive indices along the first direction and the second direction, respectively. The difference between one of the first refractive index and the second refractive index and the refractive index of the plurality of first optical microstructures is greater than or equal to 0.05. The electrically controlled phase retarder is disposed overlapping the diffractive film. The first polarizer is disposed overlapping the electrically controlled phase retarder. The first polarizer has a first absorption axis, and the axial direction of the first absorption axis is parallel to or perpendicular to the second direction.

[0009] To achieve one or part or all of the above purposes or other purposes, an embodiment of the present invention provides a display device. The display device includes a display panel and an anti-peeping module. The anti-peeping module is disposed overlapping the display panel and includes a diffractive film, an electrically controlled phase retarder, and a first polarizer. The diffractive film includes a substrate, a plurality of first optical microstructures, and a first liquid crystal layer. The substrate has a set surface, and the plurality of first optical microstructures are disposed on the set surface of the substrate. These first optical microstructures are arranged along a first direction and extend in a second direction. The first direction and the second direction intersect each other, and the first direction and the second direction are parallel to the set surface. The first liquid crystal layer is disposed on the substrate and directly covers these first optical microstructures. The positive projection of the optical axis of the first liquid crystal layer on the set surface is parallel to the second direction. The first liquid crystal layer has different first and second refractive indices along the first direction and the second direction, respectively. The difference between one of the first refractive index and the second refractive index and the refractive index of the plurality of first optical microstructures is greater than or equal to 0.05. The electrically controlled phase retarder is disposed overlapping the diffractive film. The first polarizer is disposed overlapping the electrically controlled phase retarder. The first polarizer has a first absorption axis, and the axial direction of the first absorption axis is parallel to or perpendicular to the second direction.

[0010] Based on the above, in the anti-peeping module and display device according to an embodiment of the present invention, the anisotropic diffusion film has a polarization direction selectivity for the diffusion effect of incident light, and the first absorption axis of the first polarizer is arranged parallel or perpendicular to the extending direction of the optical microstructure of the anisotropic diffusion film. By using the electro-optic phase retarder to adjust the polarization state of the light incident on or exiting from the anisotropic diffusion film, the display device can be switched between the sharing display mode and the anti-peeping display mode. With the arrangement of the anisotropic diffusion film, the anti-peeping effect of the anti-peeping module and the viewing angle range of the display device in the sharing display mode can be further improved.

[0011] To make the above features and advantages of the present invention more obvious and understandable, specific embodiments are given below and described in detail in conjunction with the accompanying drawings as follows. Description of the Drawings

[0012] Figure 1A and Figure 1B is a cross-sectional schematic diagram of the display device according to the first embodiment of the present invention in different operating modes.

[0013] Figure 2 is a cross-sectional schematic diagram of the anisotropic diffusion film according to another modified embodiment of the present invention.

[0014] Figure 3A and Figure 3B is a cross-sectional schematic diagram of the display device according to the second embodiment of the present invention in different operating modes.

[0015] Figure 4 and Figure 5 is a cross-sectional schematic diagram of the display device according to some other modified embodiments of the present invention.

[0016] Figure 6A and Figure 6B is a cross-sectional schematic diagram of the display device according to the third embodiment of the present invention in different operating modes.

[0017] Figure 7A and Figure 7B is a cross-sectional schematic diagram of the display device according to the fourth embodiment of the present invention in different operating modes.

[0018] Figure 8A and Figure 8B is a cross-sectional schematic diagram of the display device according to the fifth embodiment of the present invention in different operating modes.

[0019] Figure 9A and Figure 9B is a cross-sectional schematic diagram of the display device according to the sixth embodiment of the present invention in different operating modes.

[0020] Description of the Reference Numerals:

[0021] 1, 2, 2A, 2B, 3, 4, 5, 6: Display device

[0022] 10, 10A, 10B, 10C, 10D, 10E, 11A, 11B: Anti-peeking module

[0023] 100, 100”, 100A, 100B, 100C: Anisotropic diffusion film

[0024] 101: Substrate

[0025] 101s: Set surface

[0026] 120, 120A, 120B, 121, 122, 123, 121C, 122C: Optical microstructure

[0027] 120s, 121s, 122s: Interface

[0028] 150, 150B, 151, 152, 153, 151C, 152C, 250: Liquid crystal layer

[0029] 155, 255: Liquid crystal molecules

[0030] 160, 160A: Viewing angle limiter

[0031] 161, 162: Protective layer

[0032] 165: Light-shielding wall

[0033] 170, 171, 172: Compensation film

[0034] 190: Viewing angle control polarizing film

[0035] 191: Polarizing part

[0036] 193: Light-transmitting part

[0037] 200: Electrically controlled phase retarder

[0038] 201, 202: Substrate

[0039] 211, 212: Alignment layer

[0040] AX, AX1, AX2, AX3, AX1”: Absorption axis

[0041] BLU, BLU-A: Backlight module

[0042] DM: Dye molecule

[0043] DP: Display panel

[0044] DS: Display surface

[0045] ES: Light-emitting surface

[0046] LB, LBa, LBb, LBc, LBd, LB1, LB2, LB1d, LB2d, LB1s, LB2s: Light rays

[0047] LBr: Refracted light ray

[0048] LCM: Liquid crystal molecules

[0049] LCP: Liquid crystal polymer

[0050] OA, OA”, OA1, OA2, OA3: Optical axes

[0051] P1: First linear polarization

[0052] P2: Second linear polarization

[0053] PS: Polymer substrate

[0054] PSa, PSb: Substrate surfaces

[0055] POL1, POL1”: First polarizer

[0056] POL2: Second polarizer

[0057] X, Y, Z: Directions. Detailed implementation manners

[0058] Regarding the foregoing and other technical contents, features and effects of the present invention, they will be clearly presented in the following detailed description of a preferred embodiment with reference to the accompanying drawings. The directional terms mentioned in the following embodiments, such as: up, down, left, right, front or back, etc., are only with reference to the directions of the accompanying drawings. Therefore, the directional terms used are for illustration and not for limiting the present invention.

[0059] Figure 1A and Figure 1B are cross-sectional schematic diagrams of the display device according to the first embodiment of the present invention in different operation modes. Please refer to Figure 1A and Figure 1B , the display device 1 includes a display panel DP and an anti-peeking module 10. The anti-peeking module 10 is disposed overlapping the display panel DP along the direction Y. In this embodiment, the display panel DP may be a non-self-emitting display panel, such as a liquid crystal display panel, but is not limited thereto.

[0060] Therefore, the display device 1 may further include a backlight module BLU to serve as an illumination light source when the display panel DP is displaying. More specifically, the backlight module BLU has a light-emitting surface ES, and the display panel DP and the anti-peeking module 10 are disposed on one side of the light-emitting surface ES of the backlight module BLU. In this embodiment, the anti-peeking module 10 may be disposed between the display panel DP and the backlight module BLU. That is, the anti-peeking module 10 is located on the side of the display panel DP facing away from the display surface DS.

[0061] The anti-peeking module 10 includes, for example, a diffractive film 100, an electro-optic phase retarder 200, and a first polarizer POL1 that overlap each other along the direction Y. The electro-optic phase retarder 200 is disposed between the diffractive film 100 and the first polarizer POL1. In one embodiment, the first polarizer POL1 may also be integrated with the display panel DP, that is, the display panel DP and the anti-peeking module 10 may share the same polarizer, but it is not limited thereto.

[0062] The diffractive film 100 includes a substrate 101, a plurality of optical microstructures 120, and a liquid crystal layer 150. The substrate 101 has a setting surface 101s, and these optical microstructures 120 are disposed on the setting surface 101s of the substrate 101, and the setting surface 101s is, for example, a plane. Preferably, the in-plane retardation amount (R0) of the substrate 101 may be less than 50 nm.

[0063] For example, in this embodiment, the plurality of optical microstructures 120 may be arranged along the direction X (i.e., the first direction) and extend in the direction Z (i.e., the second direction). The length of each optical microstructure 120 in the direction Z is, for example, more than 10 times the width in the direction X. The cross-sectional profile of each optical microstructure 120 in the XY plane is, for example, semi-elliptical. The direction X and the direction Z may intersect each other (for example, be perpendicular to each other) and be parallel to the setting surface 101s of the substrate 101. The liquid crystal layer 150 is disposed on the substrate 101 and directly covers these optical microstructures 120. In this embodiment, the liquid crystal layer 150 is, for example, composed of a cured liquid crystal polymer (for example, composed of liquid crystal molecules and a high molecular polymer), and its optical axis OA is substantially parallel to the extending direction of the optical microstructures 120. That is, the orthographic projection of the optical axis OA of the liquid crystal layer 150 on the setting surface 101s is parallel to the direction Z.

[0064] From another perspective, the axial directions of the molecular long axes of the plurality of liquid crystal molecules 155 solidified (fixed in direction) within the liquid crystal layer 150 are generally arranged parallel to the extending direction of the plurality of micro-grooves formed between the plurality of optical microstructures 120. Therefore, the optical axis OA of the liquid crystal layer 150 has a first refractive index and a second refractive index that are different from each other along the direction X and the direction Z, respectively. It should be particularly noted that the refractive index of the optical microstructure 120 is equal to one of the first refractive index and the second refractive index. For example, in the present embodiment, the refractive index of the optical microstructure 120 may be equal to the first refractive index of the liquid crystal layer 150 along the direction X, but is not limited thereto. In another variant embodiment, the refractive index of the optical microstructure 120 may also be equal to the second refractive index of the liquid crystal layer 150 along the direction Z.

[0065] In the present embodiment, the first refractive index of the liquid crystal layer 150 is, for example, the ordinary refractive index, and its second refractive index is, for example, the extraordinary refractive index. Preferably, the difference between the first refractive index and the second refractive index of the liquid crystal layer 150 is greater than or equal to 0.05 (and, for example, less than 2). That is, the difference between one of the first refractive index and the second refractive index of the liquid crystal layer 150 and the refractive index of the optical microstructure 120 is greater than or equal to 0.05.

[0066] On the other hand, the electrically controlled phase retarder 200 may include a substrate 201, a substrate 202, an alignment layer 211, an alignment layer 212, and a liquid crystal layer 250. The alignment layer 211 and the alignment layer 212 are respectively disposed on the substrate 201 and the substrate 202. The liquid crystal layer 250 is sandwiched between the alignment layer 211 and the alignment layer 212. The liquid crystal layer 250 is, for example, composed of a plurality of nematic liquid crystal molecules 255, but is not limited thereto. For example, in the present embodiment, the alignment direction of the alignment layer 211 may be anti-parallel to the alignment direction of the alignment layer 212, and the angle with the direction Z is 45 degrees or 135 degrees (that is, for the non-energized electrically controlled phase retarder 200, the angle between the molecular long axes of the plurality of liquid crystal molecules 255 of the liquid crystal layer 250 and the direction Z is 45 degrees or 135 degrees). That is, the electrically controlled phase retarder 200 of the present embodiment may adopt the driving mode of Electrically Controlled Birefringence (ECB), and the variation range of the phase retardation amount of the liquid crystal layer 250 may be between 0λ and λ / 2 (for example, greater than or equal to 0λ and less than or equal to λ / 2), where λ is the light wavelength passing through the liquid crystal layer 250. It should be particularly noted that in the present invention, the liquid crystal molecules shown in the drawings are only schematic and do not represent the actual arrangement and axial direction of the liquid crystal molecules.

[0067] However, the present invention is not limited thereto. In other embodiments, the electrically controlled phase retarder may also adopt a driving mode of twisted nematic (TN), vertically aligned (VA), or in-plane switching (IPS), and the variation range of the phase retardation amount of the liquid crystal layer may be between 0λ and 3λ / 4. It should be specifically noted that, corresponding to different electrically controlled phase retarders, the alignment direction of the alignment layer can be designed accordingly.

[0068] Specifically, in this embodiment, the anti-peeking axis of the display device 1 is, for example, at an angle of 45 degrees or 135 degrees with the alignment direction of the liquid crystal layer 250 of the electrically controlled phase retarder 200. That is, the anti-peeking axis of this embodiment is the direction X. The first absorption axis AX1 of the first polarizer POL1 may be parallel to the direction Z, but is not limited thereto. In other embodiments, the first absorption axis AX1 may also be perpendicular to the direction Z (parallel to the direction X).

[0069] In this embodiment, a second polarizer POL2 may be provided on the side of the display panel DP facing away from the anti-peeking module 10, and the second absorption axis AX2 of the second polarizer POL2 may be perpendicular to the first absorption axis AX1 of the first polarizer POL1, but is not limited thereto. In this embodiment, the electrically controlled phase retarder 200 is located between the anisotropic diffusion film 100 and the second polarizer POL2.

[0070] The operating principle of the display device 1 will be exemplarily described below.

[0071] Please refer to Figure 1A , the backlight module BLU is used to emit light LB towards the anti-peeking module 10 and the display panel DP. The light LB in the non-polarized state has both a first linear polarization P1 (polarization direction parallel to the direction Z) and a second linear polarization P2 (polarization direction parallel to the direction X). When the non-polarized light LB passes through the anisotropic diffusion film 100, the light component with the first linear polarization P1 in the light LB will be deflected at the interface 120s between the optical microstructure 120 and the liquid crystal layer 150 due to the refractive index difference between the optical microstructure 120 and the liquid crystal layer 150 in the direction Z. On the contrary, the light component with the second linear polarization P2 in the light LB will not be deflected at the interface 120s between the optical microstructure 120 and the liquid crystal layer 150 because there is no substantial refractive index difference between the optical microstructure 120 and the liquid crystal layer 150 in the direction X.

[0072] Specifically, the light component with the first linear polarization P1 in the light beam LB will be scattered when passing through the anisotropic diffusion film 100 (as shown by the light beams LBa, LBb, and LBc), while the light component with the second linear polarization P2 in the light beam LB will not be scattered when passing through the anisotropic diffusion film 100 (as shown by the light beam LBd). In this embodiment, the non-enabled electro-control phase retarder 200 may have a phase retardation amount of λ / 2. Therefore, the scattered light beams LBa to LBc and the non-scattered light beam LBd form light beams LBa to LBc with the second linear polarization P2 and a light beam LBd with the first linear polarization P1 after passing through the non-enabled electro-control phase retarder 200.

[0073] In this embodiment, the first absorption axis AX1 of the first polarizing plate POL1 is perpendicular to the polarization direction of the second linear polarization P2 and parallel to the polarization direction of the first linear polarization P1. Therefore, the scattered light beams LBa to LBc can pass through the display panel DP and form outgoing light beams with the first linear polarization P1. On the contrary, the non-scattered light beam LBd cannot pass through the first polarizing plate POL1. That is, when the electro-control phase retarder 200 is not enabled and has a phase retardation amount of λ / 2, only the scattered light beams LBa to LBc can be emitted. That is, the angle at which the light is emitted from the display device 1 is larger (for example, the light-emitting viewing angle range is greater than the light-emitting viewing angle range of the backlight module BLU), and the display device 1 is operating in the shared display mode.

[0074] Please refer to Figure 1B , when the electro-control phase retarder 200 is enabled (for example, the major axes of most liquid crystal molecules 255 in the liquid crystal layer 250 can be parallel to the direction Y) and has a phase retardation amount of 0λ, the scattered light beams LBa to LBc with the first linear polarization P1 and being scattered still maintain the first linear polarization P1 after passing through the electro-control phase retarder 200, and thus cannot pass through the first polarizing plate POL1. On the contrary, the non-scattered light beam LBd with the second linear polarization P2 still maintains the second linear polarization P2 after passing through the electro-control phase retarder 200, and thus can pass through the first polarizing plate POL1, the display panel DP, and the second polarizing plate POL2 and form an outgoing light beam with the first linear polarization P1. That is, when the electro-control phase retarder 200 is enabled and has a phase retardation amount of 0λ, only the non-scattered light beam LBd can be emitted. That is, the angle at which the light is emitted from the display device 1 is smaller (for example, the light-emitting viewing angle range is substantially equal to the light-emitting viewing angle range of the backlight module BLU), and the display device 1 is operating in the anti-peeking display mode.

[0075] It should be particularly noted that when the display device 1 is operating in the anti-peeking display mode, the phase retardation amount of the enabled electro-control phase retarder 200 can also be an integer multiple of the wavelength in addition to 0λ.

[0076] FromFigure 1A and Figure 1B It can be seen that by using the electro - controlled phase retarder 200 to adjust the polarization state of the light emitted from the self - anisotropic diffusion film 100, the switching operation between the sharing display mode and the anti - peeping display mode of the display device 1 can be made more convenient. On the other hand, by setting the anisotropic diffusion film 100, the anti - peeping effect of the anti - peeping module 10 and the viewing angle range of the display device 1 in the sharing display mode can be further improved.

[0077] It should be noted that in this embodiment, although the number of liquid crystal layers of the anisotropic diffusion film 100 is exemplarily described as one, it does not mean that the present invention is limited thereto. In order to further enhance the scattering effect of the anisotropic diffusion film to meet the display requirements of a wide viewing angle, the anisotropic diffusion film can also be a stacked structure of multiple groups of optical microstructures and liquid crystal layers.

[0078] Figure 2 is a cross - sectional schematic view of an anisotropic diffusion film according to another variant embodiment of the present invention. As Figure 2 shown, in the anisotropic diffusion film 100A, both the number of liquid crystal layers and the number of optical microstructure layers can be multiple. For example, the anisotropic diffusion film 100A can selectively include a plurality of first optical microstructures 121, a first liquid crystal layer 151, a plurality of second optical microstructures 122, a second liquid crystal layer 152, a plurality of third optical microstructures 123, and a third liquid crystal layer 153 that are sequentially arranged on the setting surface 101s of the substrate 101.

[0079] The plurality of first optical microstructures 121 can be arranged along the direction X and extend in the direction Z. The first liquid crystal layer 151 directly covers these first optical microstructures 121. The plurality of second optical microstructures 122 can be arranged along the direction X and extend in the direction Z. The second liquid crystal layer 152 directly covers these second optical microstructures 122. The plurality of third optical microstructures 123 can be arranged along the direction X and extend in the direction Z. The third liquid crystal layer 153 directly covers these third optical microstructures 123. The optical axis OA1 of the first liquid crystal layer 151, the optical axis OA2 of the second liquid crystal layer 152, and the optical axis OA3 of the third liquid crystal layer 153 are parallel to each other and all parallel to the direction Z.

[0080] It should be particularly noted that the positive projection profiles of the first optical microstructure 121, the second optical microstructure 122, and the third optical microstructure 123 of the anisotropic diffusion film 100A on the XY plane can be selectively different, and the pitches of the first optical microstructure 121, the second optical microstructure 122, and the third optical microstructure 123 can be selectively different. For example, the cross-sectional profile of the first optical microstructure 121 can be triangular, the cross-sectional profile of the second optical microstructure 122 can be semi-elliptical, and the cross-sectional profile of the third optical microstructure 123 can be semi-circular. However, the present invention is not limited thereto. In another variant embodiment, the cross-sectional profiles of the multilayer optical microstructures can also be the same as each other.

[0081] On the other hand, the first liquid crystal layer 151 has a first refractive index and a second refractive index that are different from each other along the direction X and the direction Z, respectively, and the refractive index of the first optical microstructure 121 is equal to the first refractive index or the second refractive index. The second liquid crystal layer 152 has a third refractive index and a fourth refractive index that are different from each other along the direction X and the direction Z, respectively, and the refractive index of the second optical microstructure 122 is equal to the third refractive index or the fourth refractive index. The third liquid crystal layer 153 has a fifth refractive index and a sixth refractive index that are different from each other along the direction X and the direction Z, respectively, and the refractive index of the third optical microstructure 123 is equal to the fifth refractive index or the sixth refractive index.

[0082] For example, in the anisotropic diffusion film 100A, the refractive index of the first optical microstructure 121 can be equal to the first refractive index of the first liquid crystal layer 151, the refractive index of the second optical microstructure 122 can be equal to the third refractive index of the second liquid crystal layer 152, and the refractive index of the third optical microstructure 123 can be equal to the fifth refractive index of the third liquid crystal layer 153, but it is not limited thereto.

[0083] Since the diffusion principle of the anisotropic diffusion film 100A is similar to Figure 1A the diffusion principle of the anisotropic diffusion film 100, for a detailed description, please refer to the relevant paragraphs of the foregoing embodiments, and will not be repeated herein.

[0084] Some other embodiments will be listed below to illustrate the present disclosure in detail. The same components will be labeled with the same symbols, and the description of the same technical content will be omitted. For the omitted part, please refer to the foregoing embodiments and will not be repeated below.

[0085] Figure 3A and Figure 3B are cross-sectional schematic views of a display device according to a second embodiment of the present invention in different operating modes. Please refer to Figure 3A and Figure 3B Compared with Figure 1AFor the display device 1, the anti-peeping module 10A of the display device 2 in this embodiment further includes a viewing angle limiter 160, which is disposed between the anisotropic diffusion film 100 and the electro-control phase retarder 200.

[0086] For example, the viewing angle limiter 160 may include a polymer substrate PS, a plurality of dye molecules DM, and a plurality of liquid crystal molecules LCM. These dye molecules DM and these liquid crystal molecules LCM are dispersedly disposed within the polymer substrate PS. In this embodiment, the polymer substrate PS has a substrate surface PSa, and the axial direction of the absorption axis AX of these dye molecules DM and the molecular major axis of these liquid crystal molecules LCM may be perpendicular to the substrate surface PSa of the polymer substrate PS. It should be specifically noted that these dye molecules DM have a first absorption coefficient in the thickness direction (i.e., the direction perpendicular to the substrate surface PSa, such as direction Y), and have a second absorption coefficient in a direction perpendicular to this thickness direction (such as direction X or direction Z), and the first absorption coefficient is different from the second absorption coefficient. It should be noted that the substrate surface PSa of the polymer substrate PS overlaps with the backlight module BLU, and the aforementioned thickness direction may be the normal direction of the substrate surface PSa.

[0087] In this embodiment, the first absorption coefficient of these dye molecules DM is significantly greater than the second absorption coefficient, and the ratio of the first absorption coefficient to the second absorption coefficient is between 10 and 1000. Accordingly, the light filtering effect of the viewing angle limiter 160 at a side viewing angle and the light transmittance within the viewable angle range can be effectively increased, thereby enhancing the anti-peeping performance of the display device 10 and the overall brightness of the light rays at other viewing angles after exiting the display device 10. In a preferred embodiment, the ratio of the first absorption coefficient to the second absorption coefficient of the plurality of dye molecules DM may be between 100 and 1000.

[0088] In this embodiment, the material of the dye molecule DM may include an azo type compound or an anthraquinone type compound. The material of the liquid crystal molecule LCM may include a nematic liquid crystal material, a smectic liquid crystal material, or a discotic liquid crystal material. Under the influence of these liquid crystal molecules LCM, for example, the guest-host effect, the molecular major axis (i.e., the absorption axis AX) of the plurality of dye molecules DM dispersed among the plurality of liquid crystal molecules LCM tends to be arranged parallel to the optical axis of the liquid crystal molecules LCM. However, the present invention is not limited thereto. According to other embodiments, the liquid crystal molecules may also be materials having a chemical functional group similar to the dichroic dye structure. That is, the liquid crystal molecules LCM and the dye molecules DM in this embodiment may also be replaced by an integrated dye liquid crystal molecule.

[0089] On the other hand, the viewing angle limiter 160 may further include a protective layer 161 and a protective layer 162, which are respectively formed on the substrate surface PSa and the substrate surface PSb of the polymer substrate PS. The protective layer 161 and the protective layer 162 may be a hard coat, a low-reflection film, an anti-reflection film, an anti-smudge film, an anti-fingerprint film, an anti-glare film, an anti-scratch film, or a composite film layer of the above, but not limited thereto.

[0090] Since other components and configuration relationships of the display device 2 in this embodiment are similar to Figure 1A the display device 1, for a detailed description, please refer to the relevant paragraphs of the foregoing embodiment, and will not be elaborated herein. The following only describes the differences in the operating principles between the display device 2 in this embodiment and Figure 1A the display device 1.

[0091] Please refer to Figure 3A , in this embodiment, for the light LB1 incident on the anisotropic diffusion film 100 in the forward direction, the light component with the first linear polarization P1 will be scattered when passing through the anisotropic diffusion film 100 (as shown by the light LB1s), while the light component with the second linear polarization P2 will not be scattered when passing through the anisotropic diffusion film 100 (as shown by the light LB1d) and maintain forward emission. On the other hand, for the light LB2 incident on the anisotropic diffusion film 100 obliquely, the light component with the first linear polarization P1 will be scattered when passing through the anisotropic diffusion film 100 (as shown by the light LB2s), while the light component with the second linear polarization P2 will not be scattered when passing through the anisotropic diffusion film 100 (as shown by the light LB2d) and maintain the original oblique angle emission.

[0092] Next, since the axial direction of the absorption axis AX of the dye molecule DM of the viewing angle limiter 160 is perpendicular to the polarization direction of the first linear polarization P1 and the polarization direction of the second linear polarization P2 of the forward incident light LB1d, only part of the energy of the scattered light LB1s, LB2s with the first linear polarization P1 and the unscattered light LB1d will be absorbed when passing through the viewing angle limiter 160. On the other hand, since the polarization direction of the second linear polarization P2 of the obliquely incident and unscattered light LB2d is not perpendicular to the axial direction of the absorption axis AX of the dye molecule DM of the viewing angle limiter 160, the light LB2d will be absorbed by the dye molecule DM during the process of passing through the viewing angle limiter 160. The absorption efficiency of the viewing angle limiter 160 for the light LB2d will increase as the angle between the polarization direction of the second linear polarization P2 and the absorption axis AX of the dye molecule DM becomes smaller (i.e., the larger the oblique incident angle of the light LB2d).

[0093] In this embodiment, the unenabled electro - controlled phase retarder 200 may have a phase retardation amount of λ / 2. Therefore, the scattered light rays LB1s, LB2s and the non - scattered light ray LB1d form light rays LB1s, LB2s with a second linear polarization P2 and a light ray LB1d with a first linear polarization P1 after passing through the unenabled electro - controlled phase retarder 200.

[0094] In this embodiment, the first absorption axis AX1 of the first polarizer POL1 is perpendicular to the polarization direction of the second linear polarization P2 and parallel to the polarization direction of the first linear polarization P1. Therefore, the scattered light rays LB1s, LB2s can pass through the display panel DP and form outgoing light rays with the first linear polarization P1. On the contrary, the non - scattered light ray LB1d cannot pass through the first polarizer POL1. That is to say, when the electro - controlled phase retarder 200 is unenabled and has a phase retardation amount of λ / 2, only the scattered light rays LB1s, LB2s can be emitted. That is, the display device 2 is operating in the shared - display mode.

[0095] Please refer to Figure 3B , when the electro - controlled phase retarder 200 is enabled and has a phase retardation amount of 0λ, the scattered light rays LB1s, LB2s with the first linear polarization P1 still maintain the first linear polarization P1 after passing through the electro - controlled phase retarder 200, so they cannot pass through the first polarizer POL1. On the contrary, the non - scattered light ray LB1d with the second linear polarization P2 still maintains the second linear polarization P2 after passing through the electro - controlled phase retarder 200, so it can pass through the first polarizer POL1, the display panel DP and the second polarizer POL2 and form an outgoing light ray with the first linear polarization P1. That is to say, when the electro - controlled phase retarder 200 is enabled and has a phase retardation amount of 0λ, only the non - scattered light ray LB1d can be emitted. That is, the display device 2 is operating in the anti - peep display mode.

[0096] It should be specifically noted that, compared with the anti - peep module 10 of Figure 1A and Figure 1B , the anti - peep module 10A of this embodiment can limit the large - angle light beam emitted by the backlight module BLU through the setting of the viewing - angle limiter 160, further improving the anti - peep effect of the display device 2. In addition, the viewing - angle limiter 160 of this embodiment can also significantly improve the problem of light - energy loss of the current anti - peep film at the front viewing angle, which helps to improve the anti - peep display brightness of the display device 2.

[0097] Figure 4 and Figure 5It is a cross-sectional schematic diagram of a display device according to other modified embodiments of the present invention. Specifically, the anti-peeping module (such as the anti-peeping module 10 or the anti-peeping module 10A) can also increase the anti-peeping range through the setting of a compensation film. For example, in Figure 4 In a modified embodiment, the anti-peeping module 11A of the display device 2A may further include a compensation film 170 disposed between the first polarizer POL1 and the viewing angle limiter 160. The compensation film 170 is, for example, an A-plate compensation film. However, the present invention is not limited thereto. In Figure 5 In another modified embodiment, the anti-peeping module 11B of the display device 2B may further include two compensation films 171 and 172, and the compensation film 171 and the compensation film 172 are, for example, two A-plate compensation films with intersecting optical axes. The in-plane phase retardation amount of the A-plate compensation film may be between 100 nm and 350 nm.

[0098] It should be specifically noted that, in Figure 4 In the display device 2A, the compensation film 170 may be disposed between the electro-optic phase retarder 200 and the viewing angle limiter 160. However, in Figure 5 In the display device 2B, the two compensation films 171 and 172 may also be disposed between the electro-optic phase retarder 200 and the first polarizer POL1, and the optical axis of the compensation film 171 close to the first polarizer POL1 is perpendicular to the absorption axis AX1 of the first polarizer POL1, and the optical axis of the compensation film 172 is parallel to the absorption axis AX1 of the first polarizer POL1.

[0099] Figure 6A and Figure 6B are cross-sectional schematic diagrams of a display device according to the third embodiment of the present invention in different operating modes. Please refer to Figure 6A and Figure 6B . Compared with Figure 1A In the display device 1, the anti-peeping module 10B of the display device 3 in this embodiment further includes a viewing angle control polarizing film 190, which is disposed overlapping the electro-optic phase retarder 200. In this embodiment, the viewing angle control polarizing film 190 may be disposed between the backlight module BLU and the anisotropic diffusion film 100.

[0100] In this embodiment, the viewing angle control polarizing film 190 may include a plurality of polarizing portions 191 and a plurality of light-transmitting portions 193. These polarizing portions 191 and these light-transmitting portions 193 may be alternately arranged along the direction X and extend in the direction Z. Each polarizing portion 191 may have an absorption axis AX3 parallel to the direction Z. The material of the polarizing portion 191 may include a dichroic absorption material, and the material of the light-transmitting portion 193 may include a polymer material such as acrylic, silicone, epoxy resin, etc. For example, the dichroic absorption material may include a liquid crystal polymer LCP and a plurality of dye molecules DM, and these dye molecules DM are dispersedly arranged in the liquid crystal polymer LCP, but are not limited thereto. In another variant embodiment, the dichroic absorption material may also be a lyotropic liquid crystal cured and then immersed in a dye.

[0101] On the other hand, different from Figure 1A the anisotropic diffusion film 100, the refractive index of the optical microstructure 120A of the anisotropic diffusion film 100” in this embodiment may be equal to the second refractive index of the liquid crystal layer 150 along the direction Z. That is to say, in this embodiment, the light rays scattered by the anisotropic diffusion film 100” have a polarization direction of linearly polarized light parallel to the XY plane.

[0102] Since other components and configuration relationships of the display device 3 in this embodiment are similar to those of Figure 1A the display device 1, for detailed descriptions, please refer to the relevant paragraphs of the foregoing embodiments, and will not be repeated here. The following only describes the differences in the operating principles between the display device 3 in this embodiment and Figure 1A the display device 1.

[0103] Please refer to Figure 6A , in this embodiment, the light ray LB1 from the backlight module BLU and incident on the viewing angle control polarizing film 190 at a forward incident angle can pass through the light-transmitting portion 193 with negligible light energy loss and maintain an unpolarized state. For the light ray LB2 from the backlight module BLU and incident on the viewing angle control polarizing film 190 at an oblique incident angle, the light component having the first linear polarization P1 will be absorbed by the viewing angle control polarizing film 190 because the polarization direction is parallel to the absorption axis AX3 of the polarizing portion 191. Therefore, the unpolarized light ray LB2 will form a light ray LB2 having a second linear polarization P2 after passing through the polarizing portion 191 of the viewing angle control polarizing film 190.

[0104] When the non-polarized light beam LB1 passes through the anisotropic diffusion film 100", the light component with the second linear polarization P2 in the light beam LB1 will be refracted at the interface 120s between the optical microstructure 120A and the liquid crystal layer 150 due to the refractive index difference between the optical microstructure 120A and the liquid crystal layer 150 in the direction X. Similarly, the light beam LB2 with the second linear polarization P2 will also be refracted at the interface 120s between the optical microstructure 120A and the liquid crystal layer 150. On the contrary, the light component with the first linear polarization P1 in the light beam LB1 will not be refracted at the interface 120s between the optical microstructure 120A and the liquid crystal layer 150 because there is no substantial refractive index difference between the optical microstructure 120A and the liquid crystal layer 150 in the direction Z.

[0105] That is to say, the light component with the second linear polarization P2 in the light beam LB1 and the light beam LB2 with the second linear polarization P2 will be scattered when passing through the anisotropic diffusion film 100" (as shown by the light beams LB1s and LB2s), while the light component with the first linear polarization P1 in the light beam LB1 will not be scattered when passing through the anisotropic diffusion film 100" (as shown by the light beam LB1d).

[0106] In this embodiment, the non-activated electro-control phase retarder 200 may have a phase retardation amount of λ / 2. Therefore, the scattered light beams LB1s, LB2s and the non-scattered light beam LB1d respectively form the light beams LB1s, LB2s with the first linear polarization P1 and the light beam LB1d with the second linear polarization P2 after passing through the non-activated electro-control phase retarder 200. Therefore, the scattered light beams LB1s, LB2s cannot pass through the first polarizer POL1. On the contrary, the non-scattered light beam LB1d can pass through the display panel DP and form an outgoing light beam with the first linear polarization P1. That is to say, when the electro-control phase retarder 200 is not activated and has a phase retardation amount of λ / 2, only the non-scattered light beam LB1d can be emitted. That is, the display device 3 is operating in the anti-peeping display mode.

[0107] Please refer to Figure 6B, when the electro - controlled phase retarder 200 is enabled and has a phase retardation of 0λ, the scattered light rays LB1s and LB2s that are scattered and have the second linear polarization P2 still maintain the second linear polarization P2 after passing through the electro - controlled phase retarder 200. Therefore, they can pass through the first polarizer POL1, the display panel DP, and the second polarizer POL2 and form an outgoing light ray with the first linear polarization P1. On the contrary, the non - scattered light ray LB1d with the first linear polarization P1 still maintains the first linear polarization P1 after passing through the electro - controlled phase retarder 200. Therefore, it cannot pass through the first polarizer POL1. That is to say, when the electro - controlled phase retarder 200 is enabled and has a phase retardation of 0λ, only the scattered light rays LB1s and LB2s can exit. That is, the display device 3 is operating in the shared - display mode.

[0108] Specifically, compared with Figure 1A and Figure 1B for the anti - peeping module 10, the anti - peeping module 10B of this embodiment can further improve the anti - peeping effect of the display device 3 by setting the viewing - angle - control polarizing film 190. In addition, the viewing - angle - control polarizing film 190 of this embodiment can also significantly improve the problem of light - energy loss of the current anti - peeping film at the front viewing angle, which helps to improve the anti - peeping display brightness of the display device 3.

[0109] Figure 7A and Figure 7B are cross - sectional schematic views of the display device according to the fourth embodiment of the present invention in different operating modes. Please refer to Figure 7A and Figure 7B . The main difference between the display device 4 of this embodiment and the display device 1 in FIG. 1 is: the configuration method of the anti - peeping module is different. In this embodiment, both the first polarizer POL1” and the second polarizer POL2 are disposed on one side of the display surface DS of the display panel DP, and the electro - controlled phase retarder 200 and the anisotropic diffusion film 100B are disposed between the first polarizer POL1” and the second polarizer POL2. That is, the anti - peeping module 10C of this embodiment is disposed on one side of the display surface DS of the display panel DP.

[0110] In this embodiment, the first absorption axis AX1” of the first polarizer POL1” can be parallel to the second absorption axis AX2 of the second polarizer POL2, and both the first absorption axis AX1” and the second absorption axis AX2 are parallel to the direction X, but it is not limited thereto. In other variant embodiments, the first absorption axis AX1” and the second absorption axis AX2 can also be perpendicular to the direction X. In this embodiment, the electro - controlled phase retarder 200 is located between the anisotropic diffusion film 100B and the first polarizer POL1”, and the anisotropic diffusion film 100B is located between the second polarizer POL2 and the electro - controlled phase retarder 200.

[0111] It should be particularly noted that, in this embodiment, the multiple optical microstructures 120B of the anisotropic diffusion film 100B are arranged along the direction Z and extend in the direction X, and the optical axis OA” of the liquid crystal layer 150B directly covering these optical microstructures 120B is parallel to the direction X, but is not limited thereto. In other modified embodiments, the extending direction of these optical microstructures 120B may also be parallel to the direction Z, that is, the optical axis OA” of the liquid crystal layer 150B may also be parallel to the direction Z. On the other hand, in this embodiment, the refractive index of the optical microstructure 120B may be equal to the first refractive index of the liquid crystal layer 150B along the direction Z.

[0112] The operating principle of the display device 4 will be exemplarily described below. Please refer to Figure 7A , the light rays LB1 and LB2 from the display panel DP are incident on the first polarizer POL1” at a forward viewing angle and an oblique viewing angle respectively, and have a first linear polarization P1 after passing through the first polarizer POL1”. In this embodiment, for the electro - controlled phase retarder 200 that is not energized, the molecular long axes (or optical axes) of the multiple liquid crystal molecules 255 in its liquid crystal layer 250 may be parallel to the polarization direction of the first linear polarization P1. Therefore, whether it is the light ray LB1 incident in the forward direction or the light ray LB2 incident obliquely, they both still maintain the first linear polarization P1 after passing through the electro - controlled phase retarder 200.

[0113] The light rays LB1 and LB2 incident on the anisotropic diffusion film 100B and having the first linear polarization P1 will not be refracted at the interface 120s between the optical microstructure 120B and the liquid crystal layer 150B because there is no substantial difference in the refractive indices of the optical microstructure 120B and the liquid crystal layer 150B in the direction Z. That is, neither the light ray LB1 nor the light ray LB2 will be scattered when passing through the anisotropic diffusion film 100B. Since the light rays LB1 and LB2 passing through the anisotropic diffusion film 100B still maintain the first linear polarization P1, and the polarization direction of the first linear polarization P1 is perpendicular to the second absorption axis AX2 of the second polarizer POL2, the light rays LB1 and LB2 can both pass through the second polarizer POL2 and exit the display device 4. At this time, the display device 4 is operating in the shared display mode.

[0114] Please refer to Figure 7B, when the electro - controlled phase retarder 200 is enabled, the liquid crystal molecules 255 of the liquid crystal layer 250 are arranged to tilt along the Y - Z plane in the direction of Y. The light ray LB1 incident on the electro - controlled phase retarder 200 in the forward direction has the polarization direction of its first linear polarization P1 parallel to the Y - Z plane. Therefore, after passing through the electro - controlled phase retarder 200, the light ray LB1 still maintains the first linear polarization P1. However, for the light ray LB2 incident on the electro - controlled phase retarder 200 obliquely, the polarization direction of its first linear polarization P1 is neither perpendicular nor parallel to the molecular long axis of the liquid crystal molecules 255. Therefore, after passing through the electro - controlled phase retarder 200, the first linear polarization P1 of the light ray LB2 is converted into a second linear polarization P2.

[0115] The light ray LB1 incident on the anisotropic diffusion film 100B and having the first linear polarization P1 will not be refracted at the interface 120s between the optical microstructure 120B and the liquid crystal layer 150B because there is no substantial difference in the refractive index between the optical microstructure 120B and the liquid crystal layer 150B in the Z direction. However, the light ray LB2 incident on the anisotropic diffusion film 100B and having the second linear polarization P2 will be refracted at the interface 120s between the optical microstructure 120B and the liquid crystal layer 150B because there is a difference in the refractive index between the optical microstructure 120B and the liquid crystal layer 150B in the X direction. That is to say, the light ray LB1 will not be scattered when passing through the anisotropic diffusion film 100B, while the light ray LB2 will be scattered when passing through the anisotropic diffusion film 100B and form a scattered light ray LB2s having the second linear polarization P2.

[0116] Since the light ray LB1 passing through the anisotropic diffusion film 100B still maintains the first linear polarization P1, the light ray LB1 can pass through the second polarizer POL2 and exit the display device 4. On the contrary, the scattered light ray LB2s by the anisotropic diffusion film 100B is absorbed when passing through the second polarizer POL2 because it has the second linear polarization P2. At this time, the display device 4 is operating in the privacy - display mode.

[0117] In another variant embodiment, in order to improve the privacy - viewing range, at least one compensating film can be further disposed between the first polarizer POL1” and the second polarizer POL2, such as a C - plate compensating film (C - plate) with an out - of - plane phase retardation amount (Rth) between 200 nm and 800 nm, two A - plate compensating films with their optical axes intersecting and each in - plane phase retardation amount (R0) between 200 nm and 700 nm, or a biaxial compensating film with an in - plane phase retardation amount less than 100 nm and an out - of - plane phase retardation amount between 100 nm and 300 nm.

[0118] Figure 8A and Figure 8B is a cross - sectional schematic diagram of the display device according to the fifth embodiment of the present invention in different operating modes. Please refer to Figure 8Aand Figure 8B , the main difference between the display device 5 of this embodiment and the display device 1 of Figure 1A is that the functionality of the anisotropic diffusion film is different. Specifically, in this embodiment, the anisotropic diffusion film 100C of the display device 5 is, for example, a stacked structure of two sets of optical microstructure layers and liquid crystal layers. For example, the anisotropic diffusion film 100C may include a plurality of first optical microstructures 121C, a first liquid crystal layer 151C, a plurality of second optical microstructures 122C, and a second liquid crystal layer 152C that are sequentially stacked on the set surface 101s of the substrate 101.

[0119] The plurality of first optical microstructures 121C may be arranged along the direction X and extend in the direction Z. The first liquid crystal layer 151C directly covers these first optical microstructures 121C. The plurality of second optical microstructures 122C may be arranged along the direction X and extend in the direction Y. The second liquid crystal layer 152C directly covers these second optical microstructures 122C. The optical axis OA1 of the first liquid crystal layer 151C and the optical axis OA2 of the second liquid crystal layer 152 are parallel to each other and both parallel to the direction Z.

[0120] Since the operating principle of the anisotropic diffusion film 100C of this embodiment is similar to that of the anisotropic diffusion film 100 of Figure 1A , for a detailed description, please refer to the relevant paragraphs of the foregoing embodiment, and will not be repeated here. The following only describes the functional differences between the anisotropic diffusion film 100C of this embodiment and the anisotropic diffusion film 100 of Figure 1A .

[0121] In this embodiment, the plurality of first optical microstructures 121C and the plurality of second optical microstructures 122C of the anisotropic diffusion film 100C are a plurality of prism structures, and the slope (relative to the set surface 101s) of the interface (such as the interface 121s and the interface 122s) between each optical microstructure and the liquid crystal layer changes (such as gradually increasing) with different positions in the direction X. Through such a design, multiple incident light beams LB can generate different deflection angles when passing through different prism structures.

[0122] For example, the backlight module BLU-A of this embodiment can be a light source with high directivity (such as the light-emitting viewing angle range is less than or equal to 60 degrees or 90 degrees), and the multiple light beams LB emitted are concentrated on the front view angle. Similar to the display device 1 of Figure 1A , when the electro-optic phase retarder 200 of this embodiment is not energized, the multiple light beams LB deflected by the anisotropic diffusion film 100C form multiple deflected light beams LBr with a gradually changing light direction after passing through the first polarizer POL1, the display panel DP, and the second polarizer POL2 (as shown in Figure 8A ).

[0123] Similar toFigure 1B For the display device 1, when the electro - controlled phase retarder 200 of this embodiment is enabled, multiple light beams LB deflected by the anisotropic diffusion film 100C will be absorbed by the first polarizer POL1, and only the light component in the light beam LB that is not deflected by the anisotropic diffusion film 100C can pass through the first polarizer POL1, the display panel DP, and the second polarizer POL2 and maintain forward light emission (as Figure 8B shown).

[0124] That is to say, in this embodiment, the anti - peeping module 10D can essentially be a control module that can control the light emission direction of the display device 5. That is, the function of the anisotropic diffusion film of the present invention is not only limited to the light - scattering effect (such as the anisotropic diffusion films in the foregoing embodiments), but can also be the light - refracting effect for a highly directional light source.

[0125] Figure 9A and Figure 9B are cross - sectional schematic views of the display device according to the sixth embodiment of the present invention in different operating modes. Please refer to Figure 9A and Figure 9B , in the anti - peeping module 10E of the display device 6 of this embodiment, the viewing - angle limiter 160A is used to replace Figure 6A the viewing - angle control polarizing film 190 of the display device 3. In this embodiment, the viewing - angle limiter 160A is, for example, a light - control film (LCF) having a function of limiting the light - emission viewing - angle range of the transmitted light.

[0126] For example, the viewing - angle limiter 160A can be provided with a plurality of light - shielding walls 165, and these light - shielding walls 165 are arranged at intervals along the direction X and extend in the direction Z. The light - shielding walls 165 are used to at least partially reflect or absorb light, and the space between two adjacent light - shielding walls 165 allows light to pass through. It should be particularly noted that the arrangement direction of these light - shielding walls 165 can define the anti - peeping axis of the display device 6, that is, the anti - peeping axis is parallel to the direction X.

[0127] Since the other components and configuration relationships of the display device 6 of this embodiment are similar to those of Figure 6A the display device 3, for a detailed description, please refer to the relevant paragraphs of the foregoing embodiments, and will not be elaborated herein. The following only explains the differences in the operating principles between the display device 6 of this embodiment and Figure 6A the display device 3.

[0128] Different from Figure 6AThe light ray LB2 can partially penetrate the polarizing portion 191 of the viewing angle control polarizing film 190. The light-shielding wall 165 in this embodiment will absorb or reflect the light ray LB2, preventing it from passing through the viewing angle limiter 160A. That is to say, by setting the viewing angle limiter 160A between the backlight module BLU and the anisotropic diffusion film 100", the light-emitting viewing angle range of the backlight module BLU can be reduced, thereby improving the anti-peeping performance of the display device 6. Since the operating principles of other film layers of the display device 6 are similar to those of Figure 6A the display device 3, for a detailed description, please refer to the relevant paragraphs of the foregoing embodiments, and will not be elaborated herein.

[0129] In summary, in the anti-peeping module and the display device according to an embodiment of the present invention, the diffusion effect of the anisotropic diffusion film on the incident light has polarization direction selectivity, and the first absorption axis of the first polarizer is set parallel or perpendicular to the extending direction of the optical microstructure of the anisotropic diffusion film. By using the electro-optic phase retarder to adjust the polarization state of the light incident on or emitted from the anisotropic diffusion film, the display device can be switched between the sharing display mode and the anti-peeping display mode. By providing the anisotropic diffusion film, the anti-peeping module and the display device according to the embodiments of the present invention have at least one of the following advantages: in addition to further improving the anti-peeping effect of the anti-peeping module, the viewing angle range of the display device in the sharing display mode can also be increased.

[0130] However, the above are only the preferred embodiments of the present invention, and the scope of implementation of the present invention cannot be limited thereby. That is, all simple equivalent changes and modifications made according to the claims of the present invention and the content of the invention still fall within the scope covered by the patent of the present invention. In addition, any embodiment or claim of the present invention does not have to achieve all the purposes, advantages or features disclosed in the present invention. In addition, the abstract and the title (invention name) are only used to assist in the retrieval of patent documents and do not limit the scope of rights of the present invention. In addition, the terms "first", "second", etc. mentioned in this specification or claims are only used to name elements or distinguish different embodiments or scopes, and do not limit the upper or lower limits of the number of elements.

Claims

1. An anti-peeping module, characterized in that, The anti-peeping module includes a diffractive film, an electrically controlled phase retarder, and a first polarizer, where: The diffractive film includes a substrate, a plurality of first optical microstructures, and a first liquid crystal layer, where: The substrate has a set surface; The plurality of first optical microstructures are disposed on the set surface of the substrate, the plurality of first optical microstructures are arranged along a first direction and extend in a second direction, the first direction and the second direction intersect with each other, and the first direction and the second direction are parallel to the set surface; and The first liquid crystal layer is disposed on the substrate and directly covers the plurality of first optical microstructures, the positive projection of the optical axis of the first liquid crystal layer on the set surface is parallel to the second direction, the first liquid crystal layer has a first refractive index and a second refractive index different from each other along the first direction and the second direction respectively, and the difference between one of the first refractive index and the second refractive index and the refractive index of the plurality of first optical microstructures is greater than or equal to 0.05; The electrically controlled phase retarder is disposed overlapping the diffractive film; and The first polarizer is disposed overlapping the electrically controlled phase retarder, and the first polarizer has a first absorption axis, and the axial direction of the first absorption axis is parallel to or perpendicular to the second direction.

2. The anti-peeping module according to claim 1, characterized in that, The electrically controlled phase retarder is located between the diffractive film and the first polarizer.

3. The anti-peeping module according to claim 1, characterized in that, The anti-peeping module further includes a viewing angle limiter, where: The viewing angle limiter is disposed between the diffractive film and the electrically controlled phase retarder, and includes a polymer substrate and a plurality of dye molecules, where: The plurality of dye molecules are dispersedly disposed in the polymer substrate, the plurality of dye molecules have a first absorption coefficient in the thickness direction of the polymer substrate, the plurality of dye molecules have a second absorption coefficient in a direction perpendicular to the thickness direction, and the ratio of the first absorption coefficient to the second absorption coefficient is between 10 and 1000.

4. The anti-peeping module according to claim 3, characterized in that The anti-peeping module further includes at least one compensating film, where: The at least one compensating film is disposed between the viewing angle limiter and the first polarizer, and the in-plane phase retardation amount of the at least one compensating film is between 100 nm and 350 nm.

5. The anti-peeping module according to claim 1, characterized in that, The anti-peeping module further includes a viewing angle control polarizing film, where: The viewing angle control polarizing film is disposed overlapping the electrically controlled phase retarder, and includes a plurality of polarizing portions and a plurality of light-transmitting portions, where: The plurality of polarizing portions and the plurality of light-transmitting portions are alternately arranged along the first direction and extend in the second direction, the plurality of polarizing portions have absorption axes, and the axial directions of the absorption axes are parallel to the second direction.

6. The anti-peeping module according to claim 5, characterized in that, The plurality of polarizing portions include a liquid crystal polymer and a plurality of dye molecules, where: The plurality of dye molecules are dispersedly disposed in the liquid crystal polymer.

7. The anti-peeping module according to claim 1, wherein The plurality of first optical microstructures are a plurality of prism structures.

8. The anti-peeping module according to claim 1, characterized in that, The anti-peeping module further includes a second polarizer, where: The second polarizer has a second absorption axis, wherein the anisotropic diffusion film and the electrically controlled phase retarder are disposed between the first polarizer and the second polarizer, and the second absorption axis of the second polarizer is parallel to the first absorption axis of the first polarizer.

9. The anti-peeping module according to claim 8, wherein The electrically controlled phase retarder is located between the anisotropic diffusion film and the second polarizer.

10. The anti-peeping module according to claim 1, wherein The anisotropic diffusion film further includes a plurality of second optical microstructures and a second liquid crystal layer, wherein: The plurality of second optical microstructures are disposed on the first liquid crystal layer, and the plurality of second optical microstructures are arranged along the first direction and extend in the second direction; and The second liquid crystal layer is disposed on the first liquid crystal layer and directly covers the plurality of second optical microstructures, wherein the optical axis of the second liquid crystal layer is parallel to the second direction, the second liquid crystal layer has different third refractive index and fourth refractive index along the first direction and the second direction respectively, and the refractive index of the plurality of second optical microstructures is equal to the third refractive index or the fourth refractive index.

11. The anti-peeping module according to claim 10, characterized in that, The cross-sectional profile of each of the plurality of first optical microstructures is different from the cross-sectional profile of each of the plurality of second optical microstructures.

12. The anti-peeping module according to claim 1, characterized in that The in-plane phase retardation amount of the substrate of the anisotropic diffusion film is less than 50 nm.

13. The anti-peeping module according to claim 1, wherein The refractive index of the plurality of first optical microstructures is equal to the other one of the first refractive index and the second refractive index.

14. A display device, characterized in that, The display device includes a display panel and an anti-peeking module, wherein: The anti-peeking module is disposed overlapping the display panel, and includes an anisotropic diffusion film, an electrically controlled phase retarder and a first polarizer, wherein: The anisotropic diffusion film includes a substrate, a plurality of first optical microstructures and a first liquid crystal layer, wherein: The substrate has a set surface; The plurality of first optical microstructures are disposed on the set surface of the substrate, the plurality of first optical microstructures are arranged along a first direction and extend in a second direction, the first direction and the second direction intersect with each other, and the first direction and the second direction are parallel to the set surface; and The first liquid crystal layer is disposed on the substrate and directly covers the plurality of first optical microstructures, the projection of the optical axis of the first liquid crystal layer on the set surface is parallel to the second direction, the first liquid crystal layer has different first refractive index and second refractive index along the first direction and the second direction respectively, and the difference between one of the first refractive index and the second refractive index and the refractive index of the plurality of first optical microstructures is greater than or equal to 0.05; The electrically controlled phase retarder is disposed overlapping the anisotropic diffusion film; and The first polarizer is disposed overlapping the electrically controlled phase retarder, the first polarizer has a first absorption axis, and the axial direction of the first absorption axis is parallel to or perpendicular to the second direction.

15. The display device according to claim 14, wherein The display device further includes a backlight module, wherein: The backlight module has a light-emitting surface, wherein the display panel and the anti-peeking module are disposed on one side of the light-emitting surface of the backlight module, and the anti-peeking module is located between the display panel and the backlight module.

16. The display device according to claim 15, wherein, The anti-peeping module further includes a viewing angle limiter, where: The viewing angle limiter is disposed between the backlight module and the anisotropic diffusion film, and includes a plurality of light-shielding walls that are arranged along the first direction and extend in the second direction.

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