Dimming film and display screen

Abstract

The utility model discloses a dimming film and a display screen. The dimming film comprises a dimming layer; an adhesive layer is arranged on one side of the dimming layer; the dimming layer comprises a polymerization layer, a light alignment layer and a liquid crystal polymer optical delay layer; the adhesive layer is adhered to the polymerization layer or the liquid crystal polymer optical delay layer; the liquid crystal polymer optical retardation layer comprises at least two optical areas with different optical axis directions; the display screen is a linearly polarized light display screen, and the dimming film is connected with the display screen through an adhesive layer; according to the dimming film designed by the invention, the liquid crystal polymer optical delay layer with different optical areas is arranged, so that patterning is formed. The two patterned optical areas convert linearly polarized light emitted by the display screen into two kinds of circularly polarized light with different rotation directions, and the two kinds of circularly polarized light can be recognized by a detection tool.

Description

Technical Field

[0001] This utility model relates to the field of display screen film structure, and in particular to a dimming film and display screen. Background Technology

[0002] Excessive use of displays is considered a contributing factor to dry eye disease. Studies in different regions have found a link between eye discomfort and excessive smartphone use. Since many functions in daily life require the use of smartphones, reducing associated health risks, alleviating user symptoms, and developing better smartphone products to prevent eye symptoms are particularly important. The light emitted by smartphones is polarized, and its polarization state can be simply divided into linear and circular polarization. Linearly polarized light and circularly polarized light differ in their propagation direction and characteristics, while the characteristics of circularly polarized light are closer to those of natural light.

[0003] Existing research has demonstrated that circularly polarized LCD TVs outperform linearly polarized LCD TVs in reducing visual fatigue (Horváth G. Polarized Light and Polarization Vision in Animal Sciences. Springer; 2014.). Reading on linearly polarized smartphones can lead to dry eye, eye strain, and eye discomfort, while circularly polarized smartphones can minimize these adverse effects on dry eyes and visual fatigue in both bright and dark environments (Yujie Mou. Comparison of the influence of light between circularly polarized and linearly polarized smartphones on dry eye symptoms and asthenopia. Clinical and Translational Science. Volume 15, Issue 4, April 2022). Therefore, by adjusting the linearly polarized light emitted by the display to circularly polarized light, a range of adverse eye symptoms caused by excessive screen use can be alleviated.

[0004] Currently, the existing method is to use a circular polarizer consisting of a linear polarizer and a quarter-wave plate to convert linearly polarized light into circularly polarized light. However, for users, there is a lack of an effective and convenient verification method to confirm whether circularly polarized light has been obtained. Utility Model Content

[0005] The purpose of this invention is to address the shortcomings of existing technologies by proposing a dimming film and display screen.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: a dimming film, comprising:

[0007] dimming layer;

[0008] An adhesive layer is provided on one side of the dimming layer;

[0009] The dimming layer includes a polymer layer, a photoalignment layer, and a liquid crystal polymer optical delay layer;

[0010] The adhesive layer is bonded to the polymer layer or the liquid crystal polymer optical delay layer;

[0011] The liquid crystal polymer optical retardation layer includes at least two optical regions with different optical axis directions.

[0012] As a further description of the above technical solution: a cholesteric liquid crystal layer is provided on the other side of the dimming layer.

[0013] As a further description of the above technical solution: a protective adhesive layer is provided on the side of the cholesteric liquid crystal layer away from the liquid crystal polymer optical retardation layer.

[0014] As a further description of the above technical solution: the photoalignment layer is disposed on one side of the polymer layer, and at least one layer of the liquid crystal polymer optical retardation layer is disposed on the other side of the photoalignment layer.

[0015] As a further description of the above technical solution: the optical axis included angle between the two different optical regions (131) is in the range of 70°-110°, preferably 80°-100°.

[0016] As a further description of the above technical solution: the two different optical regions constitute a pattern.

[0017] As a further description of the above technical solution: the cholesteric liquid crystal layer has at least one or more layers, and the rotation directions of the multiple cholesteric liquid crystal layers are the same or opposite.

[0018] It also includes a display screen, the display screen being adapted to the dimming film described in any of the above technical solutions, including, the display screen being a linearly polarized light display screen, and the dimming film being connected to the display screen via an adhesive layer.

[0019] As a further description of the above technical solution: the angle between the direction of the linearly polarized light of the display screen and the optical axis of the liquid crystal polymer optical retardation layer of the dimming film is 30°-60°, preferably 35°-55°.

[0020] The above technical solution has the following advantages or beneficial effects:

[0021] The dimming film designed in this application features a liquid crystal polymer optical retardation layer with different optical regions, forming a pattern. These two patterned optical regions convert the linearly polarized light emitted from the display screen into two circularly polarized lights with different rotation directions, which can be identified by detection tools. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of the dimming film proposed in this utility model. Figure 1 ;

[0023] Figure 2 This is a schematic diagram of the structure of the dimming film proposed in this utility model. Figure 2 .

[0024] Legend:

[0025] 1. Dimming layer; 11. Polymer layer; 12. Photoalignment layer; 13. Liquid crystal polymer optical retardation layer; 131. Optical region; 2. Adhesive layer; 3. Cholesteric liquid crystal layer; 4. Protective adhesive layer. Detailed Implementation

[0026] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0027] Reference Figures 1-2 This utility model provides an embodiment of a dimming film, comprising: a dimming layer 1; an adhesive layer 2 disposed on one side of the dimming layer 1; the dimming layer 1 includes a polymer layer 11, a photoalignment layer 12, and a liquid crystal polymer optical delay layer 13; the adhesive layer 2 is bonded to the polymer layer 11 or the liquid crystal polymer optical delay layer 13; the liquid crystal polymer optical delay layer 13 includes at least two optical regions 131 with different optical axis directions; the photoalignment layer 12 is disposed on one side of the polymer layer 11, and at least one or more liquid crystal polymer optical delay layers 13 are disposed on the other side of the photoalignment layer 12; the optical axis angle of the optical regions 131 is in the range of 70°-110°, preferably 80°-100°; the liquid crystal polymer optical delay layer 13 is provided in two layers; the optical regions 131 of the two liquid crystal polymer optical delay layers 13 are disposed in non-overlapping or partially overlapping positions to form a pattern.

[0028] In this embodiment, a liquid crystal polymer optical retardation layer 13 with different optical regions is provided through the dimming film designed in this application. The in-plane optical retardation of the liquid crystal polymer optical retardation layer 13 is nλ / 8 to nλ3 / 8, preferably n3λ / 16 to nλ5 / 16, more preferably nλ / 4, where n is 1, 3, 5, ... The preparation method of the liquid crystal polymer optical retardation layer 13 can be conventionally selected by those skilled in the art, for example, nematic liquid crystal is formed by photoalignment, as described in patent US20080291389. The preparation method of the two optical regions 131 with different optical axis directions can be conventionally selected by those skilled in the art, for example, as described in US6806930B2.

[0029] Two optical regions 131 with different optical axis directions form a pattern. The patterned two optical regions 131 convert the linearly polarized light emitted by the display screen into two circularly polarized lights with different rotation directions. The two circularly polarized lights can be identified by detection tools.

[0030] The adhesive layer 2 includes, but is not limited to, pressure-sensitive adhesive and OCA adhesive.

[0031] On the other side of the dimming layer 1, a cholesteric liquid crystal layer 3 is disposed, with at least one or more layers of the cholesteric liquid crystal layer 3, and the rotation directions of the cholesteric liquid crystal layer 3 are the same or opposite.

[0032] In this embodiment, the peak wavelength of the light reflected by the cholesteric liquid crystal layer 3 is between 400-750nm, preferably between 400-450nm or 680-750nm. The liquid crystal polymer optical retardation layer 13 is closer to the display screen side, and the cholesteric liquid crystal layer 3 is closer to the observation direction side.

[0033] When the system includes multiple cholesteric liquid crystal layers 3, and the different cholesteric liquid crystal layers 3 have the same rotation direction, it is preferable that the wavelengths of the reflection peaks of the different cholesteric liquid crystal layers 3 are different, and it is preferable that the wavelengths of the reflection peaks of the different cholesteric liquid crystal layers 3 are between 400-450nm and 680-750nm, respectively.

[0034] When the system includes multiple cholesteric liquid crystal layers 3, and at least two cholesteric liquid crystal layers 3 have different rotation directions, it is preferable that the reflection peaks of the cholesteric liquid crystal layers 3 with different rotation directions overlap, and it is preferable that the peak wavelengths are between 400-450nm or 680-750nm.

[0035] A protective adhesive layer 4 is provided on the side of the cholesteric liquid crystal layer 3 away from the liquid crystal polymer optical retardation layer 13.

[0036] In this embodiment, a protective adhesive layer 4 is provided to protect the dimming film, and the material of the protective adhesive layer 4 is preferably silicone.

[0037] The embodiment also includes a display screen, which is adapted to the dimming film of any of the above technical solutions, including a linearly polarized light display screen, wherein the dimming film is connected to the display screen via an adhesive layer 2. The angle between the direction of the linearly polarized light of the display screen and the optical axis of the liquid crystal polymer optical retardation layer 13 of the dimming film is 30°-60°, preferably 35°-55°.

[0038] In this embodiment, the linearly polarized light display screen includes, but is not limited to, various displays such as smartphones, LCD TVs, computers, and iPads that emit linearly polarized light. The liquid crystal polymer optical retardation layer 13 has two optical regions 131 with different optical axis directions. Preferably, the angle between the optical axis of the two liquid crystal polymer optical retardation layers 13 with the linearly polarized light direction of the display screen is 30°-60°, more preferably 35°-55°, and more preferably 40°-50°.

[0039] The dimming film is attached to the linearly polarized display screen at the aforementioned angle. The transparent dimming film does not affect the use of the display screen. When two different optical regions 131 form a pattern, the display screen with the dimming film attached is observed using a linear polarizer, and the display screen displays content normally. When the display screen with the dimming film attached is observed using a left- or right-hand circular polarizer, a pattern of complementary brightness and darkness is observed. This feature can be used for brand protection of the display screen and to provide consumers with a convenient verification method.

[0040] Specifically, when the optical retardation value of the dimming film is n3λ / 16-nλ5 / 16, where n is 1, 3, 5..., and the optical axis of the optical retardation layer is at an angle of 40°-50° to the direction of linearly polarized light emitted by the display screen, the dimming film can convert the linearly polarized light emitted by the display screen into elliptically polarized light. When the optical retardation value of the dimming film is nλ / 4, where n is 1, 3, 5..., the dimming film can convert the linearly polarized light emitted by the display screen into circularly polarized light. When the optical axes of two different optical regions of the dimming film are at -45° and +45° to the direction of linearly polarized light emitted by the display screen, the dimming film can convert the linearly polarized light emitted by the display screen into left-handed and right-handed circularly polarized light, respectively. Linearly polarized light and circularly polarized light differ in their propagation direction and characteristics, while the characteristics of circularly polarized light are closer to those of natural light. Circularly polarized displays perform better than linearly polarized displays in reducing visual fatigue.

[0041] The dimming effect of the dimming film was verified using linear polarizers, left-handed polarizers, and right-handed polarizers. A linear polarizer was placed on a linearly polarized light display screen with the dimming film of this invention affixed. Rotating the polarizer resulted in the display screen remaining bright, indicating that the dimming film had converted the linearly polarized light emitted by the display screen into non-linearly polarized light. Left-handed and right-handed polarizers were placed on the same linearly polarized light display screen. One polarizer resulted in a bright display screen, while the other resulted in a dark display screen, indicating that the dimming film had converted the linearly polarized light emitted by the display screen into circularly polarized light. If the brightness of the display screen under the left-handed and right-handed polarizers was between bright and dark, it indicated that the dimming film had converted the linearly polarized light emitted by the display screen into elliptically polarized light.

[0042] Example 1

[0043] Reference Figure 1 A photoalignment layer 12 and a liquid crystal polymer optical retardation layer 13 are formed on the surface of an isotropic TAC polymer layer 11. The liquid crystal polymer optical retardation layer 13 is a nematic liquid crystal layer with optical axes of 0° and 90° and an optical retardation value of 138nm. The two optical regions 131 with different optical axes form the pattern "True Eye Protection". Pressure-sensitive adhesive is coated on the surface of the liquid crystal polymer optical retardation layer 13 and dried to form an adhesive layer 2. The prepared dimming film is attached to a display screen with 45° linearly polarized light, so that the optical axes of the two different optical regions 131 of the liquid crystal polymer optical retardation layer 13 are at 45° to the direction of linearly polarized light of the display screen.

[0044] Example 2

[0045] Reference Figure 2 A photoalignment layer 12 and a liquid crystal polymer optical retardation layer 13 are formed on the surface of an isotropic PMMA polymer layer 11. The liquid crystal polymer optical retardation layer 13 is a nematic liquid crystal layer with optical axes of -45° and 45° and an optical retardation value of 135nm. The two optical regions 131 with different optical axes form the pattern "True Eye Protection". A near-infrared cholesteric liquid crystal formulation is coated on the surface of the liquid crystal polymer optical retardation layer 13, dried, and cured with ultraviolet light to form a cholesteric liquid crystal layer 3. A protective silicone is coated on the surface of the cholesteric liquid crystal layer 3, and cured by ultraviolet light to form a protective adhesive layer 4. OCA adhesive is coated on the other side of the PMMA polymer layer 11, and cured by ultraviolet light to form an adhesive layer 2. The prepared dimming film is attached to a display screen with 0° linearly polarized light using OCA adhesive. The optical axes of the two different optical regions 131 of the liquid crystal polymer optical retardation layer 13 are at 45° to the direction of linearly polarized light of the display screen. The near-infrared cholesteric liquid crystal layer 3 reflects red light at an angle, and this dimming film also has a certain privacy protection and decorative effect.

[0046] Example 3

[0047] Reference Figure 2 In Example 2, a violet-based cholesteric liquid crystal formulation was coated onto the surface of the near-infrared cholesteric liquid crystal layer 3, dried, and cured under a UV lamp to form a double-layered cholesteric liquid crystal layer 3. A protective silicone was coated onto the surface of the cholesteric liquid crystal layer 3, and cured by UV irradiation to form a protective adhesive layer 4. OCA adhesive was coated onto the other side of the PMMA polymer layer 11, and cured by UV irradiation to form an adhesive layer 2. The prepared dimming film was then attached to a 0° linearly polarized light display screen using the OCA adhesive. The optical axes of the two different optical regions of the liquid crystal polymer optical retardation layer 13 were aligned at 45° with the direction of linearly polarized light from the display screen. The violet-based cholesteric liquid crystal layer reflects short-wavelength blue-violet light, while the near-infrared cholesteric liquid crystal layer reflects red light at the tilt angle.

[0048] Example 4

[0049] Reference Figures 1-2 In Example 1, left- and right-handed near-infrared cholesteric liquid crystal formulations were coated onto the surface of the liquid crystal polymer optical retardation layer 13, dried, and cured under ultraviolet light to form a cholesteric liquid crystal layer 3. A protective silicone was coated onto the surface of the cholesteric liquid crystal layer 3, and cured by irradiation with ultraviolet light to form a protective adhesive layer 4. OCA adhesive was coated onto the other side of the TAC polymer layer 11, and cured by irradiation with ultraviolet light to form an adhesive layer 2. The prepared dimming film was then attached to a 45° linearly polarized light display screen using OCA adhesive. This ensured that the optical axes of the two different optical regions 131 of the liquid crystal polymer optical retardation layer 13 were at a 45° angle to the direction of linearly polarized light on the display screen. The superimposed left- and right-handed near-infrared cholesteric liquid crystal layers reflected strong red light at the tilt angle, and the dimming film also provided good privacy protection.

[0050] Finally, it should be noted that the above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A light modulating film, characterized by, The application relates to a light-adjustable film, which comprises the following components: a light-adjustable layer (1); one side of the light-adjustable layer (1) is provided with an adhesive layer (2); the light-adjustable layer (1) comprises a polymer layer (11), a light orientation layer (12) and a liquid crystal polymer optical retardation layer (13); the adhesive layer (2) is bonded with the polymer layer (11) or the liquid crystal polymer optical retardation layer (13); the liquid crystal polymer optical retardation layer (13) comprises at least two optical regions (131) with different optical axes.

2. The light modulating thin film of claim 1, wherein: The other side of the light-adjustable layer (1) is provided with a cholesteric liquid crystal layer (3).

3. The light modulating thin film of claim 2, wherein: The side of the cholesteric liquid crystal layer (3) far from the liquid crystal polymer optical retardation layer (13) is provided with a protective adhesive layer (4).

4. The light modulating thin film of claim 1, wherein: One side of the polymer layer (11) is provided with the light orientation layer (12), and the other side of the light orientation layer (12) is provided with at least one layer of the liquid crystal polymer optical retardation layer (13).

5. The light modulating thin film of claim 1, wherein: The included angle between the optical axes of the two different optical regions (131) ranges from 70 to 110 degrees.

6. The light modulating thin film of claim 5, wherein: The two different optical regions form a pattern.

7. The light modulating thin film of claim 2, wherein: The cholesteric liquid crystal layer (3) is provided with at least one layer or multiple layers, and the chiralities of the multiple layers of the cholesteric liquid crystal layer (3) are the same or opposite.

8. A display screen, characterized by The display screen is suitable for the light-adjustable film in any one of claims 1-7, wherein the display screen is a linearly polarized light display screen, and the light-adjustable film is connected with the display screen through the adhesive layer (2).

9. The display screen of claim 8, wherein: The included angle between the linearly polarized light direction of the display screen and the angle between the optical axis of the liquid crystal polymer optical retardation layer (13) of the light-adjustable film ranges from 30 to 60 degrees.

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