Thin and light optical waveguide lens, and preparation method therefor and use thereof

Abstract

A thin and light optical waveguide lens, which can be applied to a display device. The optical waveguide lens comprises waveguide plates (1) made of a wide bandgap semiconductor material and protective films (2) made of an optical resin material; at least one surface of the waveguide plates (1) is provided with a grating structure (11); the protective films (2) are arranged on the surfaces of the waveguide plates (1), and are embedded in grating gaps of the grating structure (11); and the outer side surfaces of the corresponding protective film (2) and the grating structure (11) are approximately located on the same plane, and / or said protective film (2) covers the outer side surface of the grating structure (11). According to the optical waveguide lens, high-refractive-index glass waveguide plates (1) having a refractive index of 1.7-1.9 are replaced with the waveguide plates (1) made of the wide bandgap semiconductor material, and cover glass is replaced with the protective films (2) made of the optical resin material, such that hardening, scratch resistance, anti-fog, anti-slip, anti-smudge, high light transmittance and other functions are integrated while the waveguide plates (1) are protected on both sides, the overall thickness of the optical waveguide lens is reduced and the optical properties are improved.

Description

Light and thin optical waveguide lens and preparation method and application thereof TECHNICAL FIELD

[0001] The present application relates to the technical field of near-eye display devices, in particular to a light and thin optical waveguide lens and a preparation method and application thereof. BACKGROUND

[0002] Augmented reality technology, AR technology for short, is a technology that provides virtual information for users through images, videos, 3D models, etc. while displaying a real scene, and realizes the clever fusion of virtual information and the real world, and is the next information technology detonation point. Augmented reality glasses may replace mobile phones and become the next generation of collaborative computing platforms. Augmented reality technology represented by augmented reality glasses is currently rising in various industries, especially in the security and industrial fields. Augmented reality technology has unparalleled advantages and greatly improves the way of information interaction. The optical display scheme in the relatively mature augmented reality technology mainly includes prism scheme, birdbath scheme, free-form surface scheme, off-axis holographic lens scheme and waveguide scheme.

[0003] Among the many optical display schemes, the relief grating waveguide uses a relief grating (SRG) to replace the traditional catadioptric optical device (ROE) as the in-coupling, out-coupling and exit pupil expander in the waveguide scheme, and is considered to be the most promising implementation scheme for consumer AR glasses due to its excellent performance. The existing optical waveguide lens mainly uses high-refractive glass as the optical waveguide sheet and a cover glass that superimposes a protective grating structure to reduce the influence of external factors on the grating structure, thereby prolonging the service life of the optical waveguide lens. However, this multi-layer high-refractive glass superposition and external optical mechanical circuit make the AR glasses relatively bulky, affecting the user experience when wearing them for a long time. Therefore, in order to reduce the volume and weight of AR glasses, the thickness of the optical waveguide lens is currently reduced, or the cover glass is replaced with a resin material to achieve the purpose of weight and thickness reduction.

[0004] A light waveguide lens is disclosed in Chinese Patent No. CN116626800A, which comprises a light waveguide sheet and a cover plate. The number of light waveguide sheets is at least two, and the light waveguide sheets are stacked along the thickness direction of the light waveguide lens and are fixedly connected. The cover plate is fixedly connected with the light waveguide sheet and is located on one side or both sides of the light waveguide sheet along the thickness direction of the light waveguide lens. The cover plate is made of light-transmitting resin or light-transmitting glass. There is a first air gap between adjacent light waveguide sheets along the thickness direction of the light waveguide lens, and a second air gap between the cover plate and the light waveguide sheet. A filling piece is arranged in the first and second air gaps to fill at least part of the first and second air gaps. The filling piece is a light-transmitting piece, and the refractive index of the filling piece is 1.2-1.3.

[0005] The prior technical solution has the following defects: the optical waveguide lens is a combined structure of at least two optical waveguide pieces and a cover glass, if two 1mm optical waveguide pieces are stacked with a 0.5mm cover glass, and the first and second air gap thicknesses are 50μm, the overall thickness of the optical waveguide lens is 2.60mm, which is relatively thick and heavy; if the thickness of the optical waveguide piece and the cover glass is too thin, the mechanical strength of the optical waveguide piece is reduced, and the optical waveguide piece is easy to break when colliding in the human eye, which has a safety hazard; (2) the working principle of the surface relief grating is that the information of light and machinery is coupled out to the human eye through total reflection in the optical lens through the in-coupling grating, and the critical angle formula of total reflection is: sinC=n2 / n1, wherein n1 and n2 are the refractive indexes of the inside and outside of the waveguide piece respectively; when the cover glass and the filler are made of optical resin material, the refractive index difference of the interface of the optical waveguide piece is too small, the total reflection angle is too large, and it is difficult to provide total reflection conditions, so the reported combination of the optical waveguide piece and the cover glass must be separated by an air layer.

[0006] A kind of optical waveguide lens is disclosed in Chinese patent with publication number CN117590511A, comprising: waveguide piece, waveguide piece is equipped with diffractive microstructure;Protective piece, protective piece is used to protect the diffractive microstructure on the surface of waveguide piece;Annular glue layer, along the edge region of waveguide piece or protective piece is arranged, annular glue layer is used to connect waveguide piece and waveguide piece;Air valve assembly, set on waveguide piece or protective piece or annular glue layer, air valve assembly is used to block the gas discharge in the cavity between waveguide piece and protective piece, so that the air pressure of the cavity between waveguide piece and protective piece is greater than or equal to the air pressure of the environment where the optical waveguide lens is located.

[0007] The prior technical solution has the following defects: the protective piece and the waveguide piece in the above-mentioned optical waveguide lens are generally made of resin material or a mixture of resin material and glass material, making the optical waveguide lens thin and light in weight, but due to the thinness of the optical waveguide lens, it is easy to deform under stress or frame assembly conditions, which leads to a significant deterioration of the optical performance such as MTF and affects the use effect; although the above-mentioned optical waveguide lens forms an air layer by setting an annular glue layer and avoids the light energy loss and stray light phenomenon caused by the contact between the protective piece and the waveguide piece by attaching an air valve assembly to cope with the influence of deformation, but this undoubtedly increases the overall weight of the optical waveguide lens.

[0008] SUMMARY

[0009] In view of the deficiencies of the prior art, the first object of the present application is to provide a light and thin optical waveguide lens which has the advantages of light weight, thin thickness and good optical performance.

[0010] The second object of the present application is to provide a preparation method of a light and thin optical waveguide lens which has the advantages of simple process and high yield.

[0011] A third object of the present application is to provide an application of a light waveguide lens with the advantages of industrial production and popularization for AR glasses.

[0012] To achieve the above-mentioned first object, the present application provides the following technical solutions:

[0013] A light waveguide lens, comprising a waveguide sheet composed of a wide-bandgap semiconductor material, and a protective film composed of an optical resin material, at least one surface of the waveguide sheet has a grating structure, the protective film is arranged on the surface of the waveguide sheet and embedded in the grating gap of the grating structure, and the outer surface of the protective film and the grating structure is approximately in the same plane, and / or the protective film covers the outer surface of the grating structure.

[0014] Specifically, in the light waveguide lens of the present application, the specific meaning of the "wide-bandgap semiconductor material" refers to a semiconductor material with a band gap of 2.3eV or more, which can be, for example, one or a combination of silicon carbide (4H-SiC, 6H-SiC, 3C-SiC), gallium nitride (GaN), zinc oxide (ZnO), aluminum nitride (AlN), zinc selenide (ZnSe), indium gallium zinc oxide (IGZO O), diamond, etc.

[0015] The specific meaning of the "grating structure" refers to an optical device composed of a large number of parallel slits (grating gaps) with equal width and equal spacing, which can be, for example, a transmissive grating and / or a reflective grating.

[0016] The specific meaning of the "optical resin material" refers to a high-transparency polymer optical material that can replace inorganic glass and is widely used in the optical field, which can be, for example, one or a combination of acrylic diethylene glycol carbonate (CR-39), polymethyl methacrylate (PMMA), polycarbonate (PC).

[0017] By using the above technical solution, the high-refractive glass waveguide sheet with a refractive index of 1.7-1.9 is replaced by a wide-bandgap semiconductor material waveguide sheet, preferably a silicon carbide material with a refractive index of 2.6, and the optical resin material is directly attached to the surface of the grating structure without an air layer. In addition, a functional composite film layer composed of an anti-reflection film, a waterproof film, an anti-radiation film, and an anti-fog film can be attached to the waveguide sheet, thereby forming a single-layer light waveguide lens. The thickness of each layer of the functional composite film layer is in the nanometer range, and the thickest protective film is 3-5μm. According to the thickness of the waveguide sheet, which is 0.5mm, the light waveguide lens is approximately 0.5mm thick and has the properties of lightness, thinness, and scratch resistance.

[0018] Further, the waveguide sheet is composed of a silicon carbide material.

[0019] Further, the protective film has a refractive index of 1.50-1.60.

[0020] Further, the protective film is provided with at least two and is respectively arranged on the surfaces of the waveguide plate close to and away from the grating structure.

[0021] Further, the optical waveguide lens further comprises a functional composite film layer arranged on the surface of the protective film.

[0022] Further, the functional composite film layer comprises one or several composite films of anti-reflection film, waterproof film, anti-radiation film and anti-fog film.

[0023] Further, the functional composite film layer comprises an anti-reflection film arranged between the grating structure and the protective film, and a waterproof film, an anti-radiation film and an anti-fog film arranged in sequence on the surface of the protective film away from the grating structure.

[0024] Specifically, in the functional composite film layer of the present application, the specific meaning of "anti-reflection film" is an optical film that reduces or eliminates the reflected light of optical surfaces such as lenses, prisms, flat mirrors, etc., thereby increasing the light transmission of these elements and reducing or eliminating the stray light of the system, also known as anti-reflection film, non-limiting examples of which include magnesium fluoride, silicon oxide, aluminum oxide, silicon nitride, titanium oxide, tantalum oxide, zinc sulfide, etc.

[0025] The specific meaning of "waterproof film" is a top film with oil and water resistance, which is thin and does not change the optical properties of the anti-reflection film, non-limiting examples of which include silicone, polyester, cellulose acetate coating, zirconium oxide coating, fluoride, etc.

[0026] The specific meaning of "anti-radiation film" is that according to the electromagnetic interference shielding principle, a special coating process is adopted, and the lens has the function of resisting electromagnetic radiation after special treatment of thin film of electric conductor, non-limiting examples of which include silver oxide and other metal compounds.

[0027] The specific meaning of "anti-fog film" is a thin film with anti-fog properties, non-limiting examples of which include silicone, polyester, cellulose acetate coating, zirconium oxide coating, fluoride, etc.

[0028] To achieve the above-mentioned second object, the present application provides the following technical solutions:

[0029] A preparation method of a light and thin optical waveguide lens, comprising the following steps,

[0030] S1 coating on the surface of the waveguide plate close to the grating structure to obtain an anti-reflection film;

[0031] S2 coating films on the antireflection film surface, or the antireflection film surface and the surface of the optical waveguide sheet close to the grating structure, to obtain a protective film;

[0032] S3 coating films on the surface of the protective film close to the grating structure, or the surfaces of these protective films in sequence, to obtain a waterproof film, an anti-radiation film, and / or an anti-fog film;

[0033] S4 cutting and ink coating to obtain an optical waveguide lens.

[0034] By adopting the technical scheme, the conventional method needs to coat an antireflection film on the optical waveguide sheet and cut it, coat a functional film on the cover glass and cut it, cut the PSA into a lens profile adhesive strip, then superimpose, coat films, and obtain a multilayer optical waveguide lens, which leads to the following problems: (1) each step of coating, cutting, etc. may scratch or contaminate the optical glass with a structure, even damage the structure area (the structure area is a hundred nanometer grating, which is relatively fragile) to cause irreparable damage, affect the yield, and increase the cost, (2) superimposition alignment, parallelism, warping, etc. have a great influence on the optical parameters of the optical waveguide lens, and thus the optical waveguide lens processed in this way can only protect a single side containing a structure, and the other side of the optical glass cannot be protected, which has a certain influence on the service life and performance of the optical waveguide lens, and it is not worth sacrificing the thinness of the lens to add a layer of cover glass to protect the back of the lens.

[0035] The preparation method of the present application directly matches an antireflection film on the surface of the silicon carbide waveguide sheet, then wraps optical resin material on both sides of the silicon carbide waveguide sheet through a dipping method, selectively coats other functional films according to actual needs, and finally cuts and coats ink to obtain an optical waveguide lens, which has the following advantages: (1) fewer overall steps, no need to superimpose, and double-sided protection of the optical waveguide lens (silicon carbide waveguide sheet), (2) the silicon carbide waveguide sheet is protected after coating the antireflection film, the protective film is not easy to scratch, and the contamination of the lens during processing can be solved through cleaning, and the optical structure will not be damaged.

[0036] Further, in the S1-S3, the coating method is a spin coating method, a dipping method, and / or an evaporation method. The dipping method can be used to coat films on the antireflection film surface and the surface of the optical waveguide sheet close to the grating structure to obtain a protective film.

[0037] To achieve the third object, the present application provides the following technical scheme:

[0038] An application of a light and thin optical waveguide lens in a display device.

[0039] By adopting the technical scheme, the optical waveguide lens can be industrialized and applied in the display device, and is suitable for industrialized production and popularization and promotion of AR glasses.

[0040] Further, the display device includes a mobile phone, a tablet computer, a notebook computer, a desktop computer display, a smart watch, a naked-eye 3D display screen, a VR glasses, an AR glasses, a smart bracelet, a smart ring, a camera, smart glasses, a smart checkout display, an electronic shelf tag, a smart shopping cart display, an access control display, a vehicle-mounted center console, a makeup mirror, a projector, a refrigerator display, a head-up display, a vehicle-mounted display, a projection screen, or a television display.

[0041] To sum up, the beneficial technical effects of the present application are:

[0042] 1. The optical waveguide lens of the present application replaces the high-refractive glass waveguide piece with a refractive index of 1.7-1.9 with a wide-bandgap semiconductor material waveguide piece, and replaces the cover glass with an optical resin material protective film, which protects the waveguide piece on both sides, reduces the overall thickness of the optical waveguide lens, improves the optical performance, and can be hardened, anti-scratched, anti-fogged, anti-skid, anti-fouled, and high-transmissive.

[0043] 2. The preparation method of the present application has the advantages of simple process and high yield.

[0044] 3. The optical waveguide lens of the present application can be applied to display devices, and is suitable for industrial production and popularization and promotion of AR glasses. BRIEF DESCRIPTION OF DRAWINGS

[0045] Fig. 1 is a structural schematic diagram of a light and thin optical waveguide lens according to Embodiment 1 of the present application.

[0046] Fig. 2 is a structural schematic diagram of a light and thin optical waveguide lens according to Embodiment 10 of the present application.

[0047] Fig. 3 is a structural schematic diagram of a light and thin optical waveguide lens according to Embodiment 11 of the present application.

[0048] Fig. 4 is a structural schematic diagram of a light and thin optical waveguide lens according to Embodiment 12 of the present application.

[0049] Fig. 5 is a structural schematic diagram of a light and thin optical waveguide lens according to Embodiment 13 of the present application.

[0050] Fig. 6 is a structural schematic diagram of a light and thin optical waveguide lens according to Embodiment 14 of the present application.

[0051] In the drawings, 1 is a waveguide piece, 11 is a grating structure, 2 is a protective film, 3 is a functional composite film layer, 31 is an anti-reflection film, 32 is a waterproof film, 33 is an anti-radiation film, and 34 is an anti-fog film. DETAILED DESCRIPTION

[0052] In order to make the technical means, creative features, purposes and effects of the present application more clear and easy to understand, the present application is further described below in conjunction with the drawings and specific embodiments.

[0053] Embodiment

[0054] Embodiment 1: Referring to FIG. 1, a light waveguide lens disclosed by the present application comprises a waveguide sheet 1, two protective films 2, and a functional composite film layer 3. In order to make the light waveguide lens have the advantages of light weight, thin thickness, and good optical performance:

[0055] The waveguide sheet 1 is composed of silicon carbide material, and the front surface of the waveguide sheet 1 has a grating structure 11;

[0056] The protective film 2 is composed of HASUNCAST3010 optical resin material, and the protective film 2 is respectively arranged on the front surface and the back surface of the waveguide sheet 1 and embedded in the grating gap of the grating structure 11, and the protective film 2 located on the front surface of the waveguide sheet 1 covers the outer surface of the grating structure 11;

[0057] The functional composite film layer 3 is arranged on the protective film 2 located on the front surface of the waveguide sheet 1, and the functional composite film layer 3 comprises an anti-reflection film 31 (coating film, titanium oxide / silicon oxide composite film) arranged between the grating structure 11 and the protective film 2, and a waterproof film 32 (purchased, COATMAX AFG95L), an anti-radiation film 33 (coating film, silver oxide film), and an anti-fog film 34 (purchased, COATMAX AFG95L) arranged in sequence on the surface of the protective film 2 away from the grating structure 11.

[0058] Embodiments 2-7: A light waveguide lens disclosed by the present application, which is different from embodiment 1 in that the waveguide sheet 1 is composed of gallium nitride, zinc oxide, aluminum nitride, zinc selenide, indium gallium zinc oxide, and diamond material in sequence.

[0059] Embodiment 8: A light waveguide lens disclosed by the present application, which is different from embodiment 1 in that the refractive index of the protective film 2 is 1.56.

[0060] Embodiment 9: A light waveguide lens disclosed by the present application, which is different from embodiment 1 in that the refractive index of the protective film 2 is 1.60.

[0061] Embodiment 10: Referring to FIG. 2, a light waveguide lens disclosed by the present application, which is different from embodiment 1 in that the protective film 2 located on the front surface of the waveguide sheet 1 and the outer surface of the grating structure 11 are approximately in the same plane.

[0062] Embodiment 11: Referring to FIG. 3, a light waveguide lens disclosed by the present application is thin and light, and is different from Embodiment 1 in that the protective film 2 is provided with one and is arranged on the front surface of the waveguide lens 1.

[0063] Embodiment 12: Referring to FIG. 4, a light waveguide lens disclosed by the present application is thin and light, and is different from Embodiment 1 in that the functional composite film layer 3 does not include the waterproof film 32.

[0064] Embodiment 13: Referring to FIG. 5, a light waveguide lens disclosed by the present application is thin and light, and is different from Embodiment 1 in that the functional composite film layer 3 does not include the anti-radiation film 33.

[0065] Embodiment 14: Referring to FIG. 6, a light waveguide lens disclosed by the present application is thin and light, and is different from Embodiment 1 in that the functional composite film layer 3 does not include the anti-fogging film 34.

[0066] Embodiment 15: A preparation method of a light waveguide lens disclosed by the present application is thin and light, and is different from Embodiment 1 in that it includes the following steps,

[0067] S1: TiO2 and SiO2 are alternately coated on the surface of the waveguide lens 1 close to the grating structure 11 by using the evaporation method, the temperature is controlled to be 25℃, the carrier gas is Ar, the cavity pressure is 10-5Pa, the ion beam evaporation power is 500W, the TiO2 coating time is 200s, the SiO2 coating time is 60s, and the coating is performed for 3 times, to obtain the anti-reflection film 31;

[0068] S2: The protective film 2 (hard film) is coated on the surface of the anti-reflection film 31 and the surface of the waveguide lens 1 close to the grating structure 11 by using the dip coating method, the coating is performed in the protective film 2 (hard film) original solution under the condition of 40kHz ultrasonic oscillation and 50mm·min-1 pulling speed, and the protective film 2 is obtained by heat treatment at 80℃ for 1h solidification;

[0069] S3: The waterproof film 32 is coated on the surface of the protective film 2 close to the grating structure 11 by using the spin coating method, the initial rotating speed is controlled to be 500rpm, the rotating speed is changed to 3000rpm after 5s, the spin coating is performed for 60s, the remaining solvent is baked by the hot plate at 130℃, and the waterproof film 32 is obtained;

[0070] The anti-radiation film 33 is coated on the surface of the protective film 2 close to the grating structure 11 by using the spin coating method, the DC target position is controlled, the working current is controlled to be 35mA, the carrier gas is Ar, the coating time is 30s, and the anti-radiation film 33 is obtained;

[0071] The anti-fogging film 34 is coated on the surface of the protective film 2 close to the grating structure 11 by using the spin coating method, the initial rotating speed is controlled to be 500rpm, the rotating speed is changed to 3000rpm after 5s, the spin coating is performed for 60s, the remaining solvent is baked by the hot plate at 130℃, and the anti-fogging film 34 is obtained

[0072] S4 cutting, ink coating, to get the optical waveguide lens.

[0073] Embodiment 16: The application of a light and thin optical waveguide lens disclosed in the present application in a display device, which is different from embodiment 1 in that the display device is AR glasses.

[0074] Comparative example

[0075] Comparative example 1: A light and thin optical waveguide lens disclosed in the present application, which is different from embodiment 1 in that the waveguide sheet 1 is composed of high-refractive glass, and the refractive index is 1.7, 1.8, and 1.9 in turn.

[0076] Comparative example 2: A light and thin optical waveguide lens disclosed in the present application, which is different from embodiment 1 in that the protective film 2 is composed of light-transmitting glass.

[0077] Comparative example 3: A light and thin optical waveguide lens disclosed in the present application, which is different from embodiment 1 in that an air gap layer (not shown in the figure) is reserved between the protective film 2 on the front of the waveguide sheet 1 and the outer surface of the grating structure 11.

[0078] Performance detection test

[0079] 1. Hardness test: The hardness of the optical waveguide lenses of embodiments 1-14 was tested by using a Shore hardness tester. The results showed that the hardness of the optical waveguide lenses was more than 80D.

[0080] 2. Transmittance test: The transmittance of the optical waveguide lenses of embodiments 1-14 was tested by using an ultraviolet spectrophotometer, and the test range was 400-800 nm. The results showed that the transmittance of the optical waveguide lenses was more than 98%. Among them, the transmittance of the optical waveguide lens of embodiment 13 was the highest, and it was speculated that the anti-radiation film would reduce the visible light transmittance a little.

[0081] 3. Weight test: The weight of the optical waveguide lenses of embodiments 1-14 (35*50*0.4mm, length*width*thickness) was tested by using an analytical balance. The results showed that after the modification of the protective film 2, the anti-fog film 34, and / or the anti-radiation film, the mass of the optical waveguide lens was about 0.5g, which was much lower than the weight of comparative examples 1-2.

[0082] 4. Total reflection critical angle test: The total reflection critical angle of the optical waveguide lenses of embodiment 1 and comparative example 1 was tested, and the results are shown in Table 1. As can be seen from Table 1, the smaller the total reflection critical angle, the higher the transmission efficiency of light in the waveguide lens. The optical waveguide lens of the present application is far superior to comparative examples 1-3 in terms of optical performance such as total reflection critical angle, spherical aberration, and chromatic aberration, as well as physical properties such as appearance, thickness, wear resistance, impact resistance, and temperature resistance.

[0083] Table 1

[0084] Finally, it should be pointed out that the above embodiments are only used to illustrate the technical solutions of the present application but not to limit the present application. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or equivalently replaced without departing from the purpose and scope of the present application, and all of them should be covered in the scope of the claims of the present application.

Claims

1. A thin and light waveguide lens, characterized by: The invention comprises a waveguide plate (1) composed of a wide bandgap semiconductor material and a protective film (2) composed of an optical resin material, wherein at least one surface of the waveguide plate (1) has a grating structure (11), the protective film (2) is arranged on the surface of the waveguide plate (1) and embedded in the grating gap of the grating structure (11), and the outer surface of the protective film (2) and the grating structure (11) are approximately on the same plane, and / or the protective film (2) covers the outer surface of the grating structure (11).

2. The thin and light waveguide lens according to claim 1, characterized in that: The waveguide plate (1) is made of silicon carbide material.

3. The thin and light waveguide lens according to claim 1, characterized in that: The refractive index of the protective film (2) is 1.50 to 1.

60.

4. The thin and light waveguide lens according to claim 1, characterized in that: At least two protective films (2) are provided and are respectively provided on the surface of the waveguide plate (1) close to and away from the grating structure (11).

5. The thin and light waveguide lens according to claim 1, characterized in that: The optical waveguide lens further comprises a functional composite film layer (3), and the functional composite film layer (3) is arranged on the surface of the protective film (2).

6. The thin and light waveguide lens according to claim 5, characterized in that: The functional composite film layer (3) comprises one or more composite films selected from the group consisting of an anti-reflection film (31), a waterproof film (32), an anti-radiation film (33) and an anti-fog film (34).

7. The thin and light waveguide lens according to claim 6, characterized in that: The functional composite film layer (3) comprises an anti-reflection film (31) arranged between the grating structure (11) and the protective film (2), and a waterproof film (32), an anti-radiation film (33), and an anti-fog film (34) arranged in sequence on a surface of the protective film (2) facing away from the grating structure (11).

8. A method for preparing a thin and light waveguide lens according to any one of claims 1 to 7, characterized in that: The following steps are included: S1: coating the surface of the optical waveguide plate (1) close to the grating structure (11) to obtain an anti-reflection film (31); S2 coats the surface of the anti-reflection film (31), or the surface of the anti-reflection film (31) and the surface of the optical waveguide plate (1) close to the grating structure (11), to obtain a protective film (2); S3 coating the surface of the protective film (2) close to the grating structure (11) or the surfaces of these protective films (2) in sequence to obtain a waterproof film (32), an anti-radiation film (33), and / or an anti-fog film (34); S4 cutting, ink coating, and optical waveguide lens are obtained.

9. The method for preparing a light and thin optical waveguide lens according to claim 8, characterized in that: In the above-mentioned S1 to S3, the coating method is a spin coating method, a dip coating method, and / or an evaporation method.

10. Use of the light and thin optical waveguide lens according to any one of claims 1 to 7 in a display device.

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