Augmented Reality Optical Lenses with Eye Protection Function and Preparation Method Thereof

Abstract

The present invention provides an augmented reality optical lens with an eye protection function and a preparation method thereof. Aiming at the heat dissipation and eye protection problems of head-mounted display devices, a silicon carbide substrate is used, and specific optical thin film structures are provided on both sides thereof. When the device generates heat, a heat conduction belt connects the heating element and the lens, and the heat is dissipated by the heat conduction of silicon carbide. The heat dissipation is enhanced by heat exchange with air and controlling the direction of infrared radiation, preventing the human eye from being exposed to heat radiation. The infrared radiation layer of the optical thin film controls the transmittance of multi-band light, realizing the function of preventing ultraviolet and blue light. The present invention integrates the functions of heat dissipation and eye protection, has a simple process and a high yield, meets the requirements of miniaturization, long battery life and eye protection of head-mounted devices, improves the user experience, and promotes the development of augmented reality technology devices.

Description

Technical Field

[0001] The present invention relates to the field of optical technologies, and particularly to an augmented reality optical lens with an eye protection function and a preparation method thereof. Background Art

[0002] In the booming process of mixed reality technology, in order to meet the requirements of functional integration in head-mounted display devices, the number of internal electronic components has been continuously increasing, resulting in a large accumulation of heat during device operation. Heat dissipation has become a key challenge, and due to direct contact with the human skin, strict requirements for heat dissipation are imposed.

[0003] Traditional heat dissipation methods mainly include fan heat dissipation and metal frame / heat sink heat dissipation. Although fan heat dissipation can actively exhaust heat, it significantly increases the volume and weight of the device, and the additional power consumption causes the battery life to decline, which is contrary to the pursuit of miniaturization and long battery life of head-mounted devices. Although the metal heat sink can conduct heat, as an additional component, it increases the device load and reduces the wearing comfort. Although the metal frame can conduct some heat, the effective convection area is limited, and direct contact needs to be avoided to prevent skin burns, resulting in a significant reduction in heat dissipation effect.

[0004] To solve the heat dissipation dilemma, the existing technology uses silicon carbide lenses, which use their high thermal conductivity to direct heat to the lenses to expand the heat dissipation area, and regulate the thermal radiation and visible light transmittance to improve the heat dissipation efficiency (as shown in patent CN116857844A). However, in this solution, the same radiation enhancement film is plated on both sides of the silicon carbide lens, resulting in the human eye being exposed to infrared thermal radiation with a radiation rate of up to 60% during long-term use. Due to the strong penetration of infrared radiation, the vulnerable tissues such as the human cornea are heated and accumulated, which can cause irreversible damage. In addition, augmented reality glasses are worn in daily scenarios and should have the functions of preventing ultraviolet rays and blue light. The existing technology lacks comprehensive eye protection and cannot meet the user's demands for improving the protection effect and wearing comfort of the device.

[0005] Therefore, there is an urgent need for an augmented reality optical lens with an eye protection function and a preparation method thereof to solve the problems existing in the existing technology. Summary of the Invention

[0006] The embodiments of the present invention provide an augmented reality optical lens with an eye protection function and a preparation method thereof. Aiming at the deficiencies in the heat dissipation technology of current head-mounted display devices, although the use of silicon carbide lenses can dissipate heat, the plating of the same film on both sides causes strong infrared thermal radiation damage to the human eye, and there is a lack of ultraviolet and blue light protection functions, which cannot meet the requirements of device miniaturization, long battery life, and comprehensive eye protection.

[0007] The core technology of the present invention is mainly based on silicon carbide, a material with high thermal conductivity. An optical thin film is deposited on the surface of the material to increase the infrared emissivity and visible light transmittance. At the same time, blue light prevention and heat radiation direction control designs are carried out to use this as the lens of the augmented reality glasses.

[0008] In a first aspect, the present invention provides an augmented reality optical lens with eye protection function, including:

[0009] A substrate made of silicon carbide material, with optical thin film structures respectively arranged on both sides of the substrate;

[0010] The optical thin film structures on the side facing the human eye are, in sequence, an infrared radiation layer, an infrared reflection layer, and a low refractive index dielectric layer; the optical thin film structures on the side facing the environment are, in sequence, an infrared reflection layer and an infrared radiation layer;

[0011] A heat conduction belt, with one end thermally connected to the lens and the other end located outside the lens, for connecting a heating element;

[0012] When the device generates heat, the heating element is connected to the lens through the heat conduction belt, and the heat is distributed on the lens by using the thermal conductivity of silicon carbide, and heat exchange and dissipation occur with the surrounding air; and in the outdoor environment, the infrared radiation direction is regulated by the optical thin film, so that the heat is radiated in the opposite direction of the human eye in the atmospheric window band;

[0013] The infrared emissivity of the infrared radiation layer facing the environment reaches more than 0.5 in the atmospheric window band, the infrared emissivity facing the human eye is less than 0.6 in the atmospheric window band, and at the same time, the transmittance reaches more than 0.55 in the range of 455nm - 700nm, the transmittance does not exceed 0.7 in the wavelength range of 200 - 380nm, and more than 5% of blue light is blocked between 380 - 455nm; the atmospheric window band of the infrared reflection layer is between 8 - 14um.

[0014] Further, the infrared reflection layer uses an optical thin film material with high transmittance in the visible light range and a reflectance of more than 50% in the atmospheric window band.

[0015] Further, the infrared radiation layer uses a film layer structure with alternating high and low refractive index materials. The total number of alternating film layers is 4 - 100 layers, the thickness of each layer is 10 - 500nm, and the total thickness is 0.2 - 5um.

[0016] Further, the low refractive index dielectric layer facing the human eye direction is magnesium fluoride.

[0017] Further, the infrared reflection layer uses indium tin oxide.

[0018] Further, the high refractive index material of the infrared radiation layer is titanium dioxide or hafnium dioxide, and the low refractive index material is silicon dioxide.

[0019] Further, the heat conduction band is made of graphene or copper tape.

[0020] Further, the thickness of the infrared reflection layer facing the human eye direction is 100 nm, and the thickness facing the environment direction is 10 nm.

[0021] In a second aspect, the present invention provides a method for manufacturing an augmented reality optical lens with eye protection function, including:

[0022] S00. Input the optimization objectives on the simulation software, including visible light transmittance and infrared radiation rate;

[0023] S10. Input the initial structure, establish the model of the lens, optimize the thickness of each layer using the simulation software, obtain the final optimized thickness of each layer of the lens, and obtain the final design value;

[0024] S20. Use the thin film deposition method to deposit the materials on the substrate in sequence according to the final design value.

[0025] The main contributions and innovations of the present invention are as follows:

[0026] 1) Infrared thermal radiation protection: The present invention precisely controls the direction of thermal radiation. By means of a unique optical thin film structure, differential film layers are provided on both sides of the silicon carbide lens. The side facing the human eye effectively blocks the heat generated during the operation of the device, making the infrared radiation directed outward from the eye. Compared with the existing technology of double-sided coating with the same film resulting in a 60% radiation rate and harming the eyes, the risk of heat accumulation in the human eye is significantly reduced, protecting vulnerable tissues such as the cornea and ensuring the physiological functions of the eyes.

[0027] 2) Blue light and ultraviolet light protection: The infrared radiation layer of the optical thin film has the characteristics of simultaneously preventing ultraviolet and blue light. It blocks more than 40% of blue light in the range of 380 - 455 nm (more than 45% is blocked by a specific structure), and controls the ultraviolet light transmittance in the range of 200 - 380 nm to be as low as 0.5 or less, preventing the aging and lesions of eye structures, improving the level of visual health, expanding the daily wearing time scenario of augmented reality glasses, and making up for the shortcoming of eye protection in the existing technology.

[0028] 3) Efficient passive heat dissipation: The silicon carbide lens is combined with a heat conduction band to construct an efficient heat conduction path, quickly spreading the heat of the component above 60 °C to the lens. Utilize the natural convection of the lens and the low-temperature air, and according to the principles of aerodynamics and heat exchange, form a stable heat dissipation flow, improve the heat dissipation efficiency, reduce the risk of heat loss of the device, reduce the dependence on active heat dissipation components such as fans, avoid increasing the volume, weight and power consumption of the device, and ensure the compactness, lightness and long battery life of the head-mounted device.

[0029] 4) Enhanced heat radiation dissipation: By precisely regulating the infrared radiation in the atmospheric window (8 - 14μm) band with an optical thin film, the radiation efficiency of the lens to the environment is increased, and heat is efficiently discharged to the low-temperature region of outer space (about 3K). Compared with existing heat dissipation limitation technologies, it expands the heat dissipation dimension, improves the heat dissipation power, ensures the stable operation of the device under high load, and provides an innovative solution to the heat dissipation problem of high-integration functional modules.

[0030] 5) High visible light transmittance: Through optimized design and fine processes of the optical thin film layer, the transmittance of the lens is improved in the visible light band of 400 - 700nm, ensuring clear images and true colors in the augmented reality scene, enhancing the user's visual immersive interaction experience, and leading in the balance between optical performance and functional integration.

[0031] 6) Excellent process: From the precise design of the film layer structure parameters based on software algorithms to mature coating processes such as electron beam evaporation and magnetron sputtering, the solution of the present invention has a mature process, controllable parameters, and a high yield rate, is suitable for mass production, reduces the manufacturing cost, shortens the production cycle, accelerates the market promotion and application of products, and enhances the market competitiveness.

[0032] Details of one or more embodiments of the present invention are set forth in the following drawings and description to make other features, objects, and advantages of the present invention more concise and understandable. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0034] Figure 1 is a schematic structural diagram of an augmented reality optical lens with eye protection function according to an embodiment of the present invention;

[0035] Figure 2 is an infrared radiation rate curve graph of the augmented reality optical lens with eye protection function facing the environment according to an embodiment of the present invention;

[0036] Figure 3 is an infrared radiation rate curve graph of the augmented reality optical lens with eye protection function facing the human eye according to an embodiment of the present invention;

[0037] Figure 4 is a simulated visible light transmittance curve graph according to an embodiment of the present invention;

[0038] Figure 5 is an infrared radiation rate graph of the environment measured actually according to an embodiment of the present invention;

[0039] Figure 6is the infrared emissivity map measured actually according to the embodiment of the present invention towards the human eye;

[0040] Figure 7 is the visible light transmittance curve measured actually according to the embodiment of the present invention. Specific Embodiments

[0041] Here, the exemplary embodiments will be described in detail, and the examples are shown in the drawings. When the following description refers to the drawings, unless otherwise indicated, the same numerals in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with one or more embodiments of this specification. On the contrary, they are merely examples of devices and methods consistent with some aspects of one or more embodiments of this specification as detailed in the appended claims.

[0042] It should be noted that: In other embodiments, the steps of the corresponding methods are not necessarily executed in the order shown and described in this specification. In some other embodiments, the steps included in the method may be more or less than those described in this specification. In addition, a single step described in this specification may be decomposed into multiple steps for description in other embodiments; and multiple steps described in this specification may also be combined into a single step for description in other embodiments.

[0043] In the prior art CN116857844A, the same radiation enhancement thin films are coated on both sides of the silicon carbide lens, which causes the human eye to suffer from long-term infrared thermal radiation, and the emissivity can reach 60%. The penetration ability of infrared radiation is relatively strong. At the same time, different from the skin, the human eye has relatively fragile biological structures such as the cornea. Due to the heat accumulation generated by the infrared radiation, it will cause irreversible damage to the human eye. In addition, even for augmented reality glasses, since they can be worn daily, they should also meet the functions of blocking ultraviolet rays and blue light, providing higher protection effects and wearing comfort for users, and preventing blue light damage caused by electronic products.

[0044] Based on this, the present invention is based on a new technical solution to solve the problems existing in the prior art. The solution of the present invention is based on silicon carbide, a material with high thermal conductivity. An optical thin film is deposited on the material surface to achieve the effects of increasing the infrared emissivity and visible light transmittance, and at the same time, the design of blocking blue light and controlling the direction of thermal radiation is carried out, and this is used as the lens of the augmented reality glasses.

[0045] Embodiment 1

[0046] The present invention aims to propose an augmented reality optical lens with an eye protection function. Specifically, refer to Figure 1, including a substrate, an optical thin film structure, and a heat conducting band. Optical thin film structures are arranged on both sides of the substrate to form a silicon carbide lens. One end of the heat conducting band is adhered to the lens through heat conducting adhesive, and the other end is located outside the lens for connecting a heating element.

[0047] The specific solution is that when the augmented reality glasses generate heat due to the operation of highly integrated components (usually higher than 60 °C), the heating element is connected to the silicon carbide lens through a heat conducting band (generally made of materials with high heat conduction efficiency such as graphene or copper tape). Utilizing the extremely high thermal conductivity of silicon carbide, the heat generated by the electronic components is distributed across the entire lens surface, thereby obtaining a larger convection area and performing more efficient heat exchange with the relatively cooler surrounding air to achieve the purpose of heat dissipation. At the same time, under outdoor conditions, by using the optical thin film structure deposited on the silicon carbide, the infrared emissivity is regulated to make its radiation stronger in the atmospheric window (8 - 14 μm) band and only towards the opposite direction of the human eye. Thus, heat can be radiated to the extremely low-temperature outer space (3K) through the electromagnetic waves in this band, further improving the heat dissipation capacity while preventing the human eye from being damaged by long-term thermal radiation. In addition, the optical thin film structure on the silicon carbide lens can effectively filter blue light to protect the human eye.

[0048] More specifically, as Figure 1 shown, the silicon carbide lens includes a substrate; an infrared reflection layer; an infrared radiation layer; a low refractive index dielectric layer. For the interface of the silicon carbide lens facing the human eye, the structure of the optical thin film is the substrate, the infrared radiation layer, the infrared reflection layer, and the low refractive index dielectric layer, while for the interface facing the environment, the structure of the optical thin film is successively the substrate, the infrared reflection layer, and the infrared radiation layer.

[0049] In this embodiment, the infrared reflection layer is an optical thin film with a relatively high transmittance in the visible light range and a reflectance of more than 50% in the atmospheric window band. For example, indium tin oxide has the properties of visible light transparency and infrared reflection and is a good material for the infrared reflection layer, but it is not limited to indium tin oxide. Its function is to maintain a high transmittance in the visible light range, further increasing the infrared emissivity at the interface facing the environment direction, while at the interface facing the human eye direction, the infrared reflection layer outside the infrared radiation layer blocks the heat radiated by infrared to prevent it from radiating to the human eye; the atmospheric window band is between 8 - 13 μm.

[0050] In this embodiment, the infrared radiation layer refers to a layer with an infrared emissivity facing the environment reaching above 0.5 in the atmospheric window band, while the infrared emissivity facing the human eye is below 0.5 in the atmospheric window band. Additionally, the transmittance is very high in the range of 455nm - 700nm, reaching above 0.65; it has an anti-ultraviolet effect, that is, the transmittance does not exceed 0.5 in the wavelength range of 200 - 380nm. At the same time, it has an anti-blue light effect, that is, it blocks more than 40% of the blue light between 380 - 455nm. Generally, a film layer structure with alternating high and low refractive index materials is adopted. This structure can meet the conditions of optical thin film interference, so it can regulate the transmittance and reflectivity. For example, for the antireflection film in the present invention, by adjusting the film layer thickness, this structure can make the transmitted light interfere constructively and the reflected light interfere destructively, thereby increasing the light transmittance. For the infrared radiation layer facing the environment, on the premise of meeting the refractive index requirements, the film layer material also needs to have absorption in the atmospheric window band, so as to achieve the purpose of increasing infrared radiation. For example, high refractive index materials such as titanium dioxide and hafnium dioxide are used, and low refractive index materials such as silicon dioxide are used. The low refractive index dielectric layer facing the human eye direction can be magnesium fluoride because of its low refractive index and its inability to enhance radiation in the infrared band.

[0051] Preferably, the infrared radiation layer adopts a film layer structure with alternating high and low refractive index materials. The total number of alternating film layers is 4 - 100 layers, the thickness of each layer is 10 - 500nm, and the total thickness is 0.2 - 5um.

[0052] Preferably, the substrate thickness is 0.2 - 4mm, the number of film layers of the infrared reflection layer is 1 - 10 layers, and the thickness of each layer is 5 - 500nm; the number of film layers of the infrared radiation layer is 4 - 50 layers, and the thickness of each layer is 5 - 500nm; the thickness of the low refractive index dielectric layer is 5 - 500nm;

[0053] In this embodiment, indium tin oxide is used for the infrared reflection layer, with a thickness of 100nm facing the human eye direction and a thickness of 10nm facing the environment direction; silicon dioxide and hafnium dioxide are used as the low refractive index material and the high refractive index material respectively for the infrared radiation layer, and magnesium fluoride is used for the low refractive index dielectric layer. The film layer structure and thickness from the environment to the human eye direction are as shown in Table 1 (used to show the specific film system structure in a specific embodiment, specifically the thickness and material of each layer):

[0054] Table 1

[0055] Material Thickness <![CDATA[SiO2]]> 84.23 nm <![CDATA[HfO2]]> 101.75 nm <![CDATA[SiO2]]> 192.35 nm <![CDATA[HfO2]]> 166.72 nm <![CDATA[SiO2]]> 207.36 nm <![CDATA[HfO2]]> 143.42 nm <![CDATA[SiO2]]> 163.02 nm <![CDATA[HfO2]]> 150.33 nm <![CDATA[SiO2]]> 55.45 nm <![CDATA[HfO2]]> 76.62 nm ITO 10 nm SiC (Substrate) 500μm <![CDATA[HfO2]]> 85.4 nm <![CDATA[SiO2]]> 56.47 nm <![CDATA[HfO2]]> 163.82 nm <![CDATA[SiO2]]> 209.45 nm <![CDATA[HfO2]]> 57.33 nm <![CDATA[SiO2]]> 207.29 nm <![CDATA[HfO2]]> 130.87 nm ITO 100 nm <![CDATA[MgF2]]> 98.96 nm

[0056] The anti-radiation functional characteristics achieved by the structure of the present invention Figure 2 and Figure 3Shown are the emissivity towards the environment direction and the emissivity towards the human eye direction respectively. The anti-ultraviolet (UV) and anti-blue light functional characteristics achieved by the present invention, after measurement, the transmittance in the 200 - 380 nm band is less than 0.37, and in the blue light band of 380 - 455 nm, 45% of the harmful blue light is effectively blocked. As Figure 4 is the simulated visible light transmittance curve graph, Figure 5 is the infrared emissivity towards the environment obtained by actual measurement, Figure 6 is the infrared emissivity towards the human eye obtained by actual measurement, Figure 7 is the visible light transmittance curve obtained by actual measurement.

[0057] Embodiment 2

[0058] Based on the same concept, the present invention also proposes a preparation method of an augmented reality optical lens with an eye protection function, including:

[0059] S00. Input the optimization objectives on the simulation software, including visible light transmittance and infrared emissivity;

[0060] S10. Input the initial structure, establish the model of the lens, optimize the thickness of each layer using the simulation software, obtain the final optimized thickness of each layer of the lens, and obtain the final design value;

[0061] S20. Use the thin film deposition method to deposit the materials on the substrate in sequence according to the final design value.

[0062] Preferably, deposit the materials on the substrate in sequence according to the final design value by electron beam evaporation coating or magnetron sputtering coating.

[0063] Those skilled in the art should understand that the technical features of the above embodiments can be combined arbitrarily. For the sake of concise description, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combination of these technical features does not conflict, it should be considered as the scope recorded in this specification.

[0064] The above embodiments only represent several implementation manners of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several deformations and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the appended claims.

Claims

1. An augmented reality optical lens with an eye protection function, characterized in that, Including: A substrate made of silicon carbide material, with optical thin film structures respectively arranged on both sides of the substrate; The optical thin film structures on the side facing the human eye are, in sequence, an infrared radiation layer, an infrared reflection layer, and a low refractive index dielectric layer; the optical thin film structures on the side facing the environment are, in sequence, an infrared reflection layer and an infrared radiation layer; A heat conducting belt, with one end thermally connected to the lens and the other end located outside the lens, for connecting a heating element; When the device generates heat, the heating element is connected to the lens through the heat conducting belt, and the heat is distributed on the lens by using the thermal conductivity of silicon carbide, and heat exchange with the surrounding air is carried out for heat dissipation; and outdoors, the infrared radiation direction is regulated by the optical thin film, so that the heat is radiated in the opposite direction of the human eye in the atmospheric window band; The infrared radiation rate of the infrared radiation layer facing the environment reaches more than 0.5 in the atmospheric window band, the infrared radiation rate facing the human eye is less than 0.6 in the atmospheric window band, meanwhile, the transmittance reaches more than 0.55 at 455nm - 700nm, the transmittance does not exceed 0.7 in the wavelength range of 200 - 380nm, and more than 5% of blue light is blocked between 380 - 455nm; the atmospheric window band of the infrared reflection layer is between 8 - 14um, and the infrared reflection layer uses an optical thin film material with a high transmittance in the visible light range and a reflectance of more than 50% in the atmospheric window band.

2. The augmented reality optical lens with an eye protection function according to claim 1, wherein, The thickness of the substrate is 0.2 - 4mm.

3. An augmented reality optical lens with an eye protection function according to claim 1, characterized in that, The low refractive index dielectric layer facing the human eye direction is magnesium fluoride, and the thickness is between 5 - 500nm.

4. The augmented reality optical lens with an eye protection function according to claim 1, characterized in that, The infrared reflection layer uses indium tin oxide, and the number of layers is 1 - 10 layers, and the thickness of each layer is between 5 - 500nm.

5. The augmented reality optical lens with an eye protection function according to claim 2, characterized in that, The infrared radiation layer uses a film layer structure with alternating high and low refractive index materials, where the high refractive index material is titanium dioxide or hafnium dioxide, the low refractive index material is silicon dioxide, the total number of alternating film layers is 4 - 50 layers, and the thickness of each layer is between 5 - 500nm.

6. An augmented reality optical lens with an eye protection function according to claim 1, characterized in that, The heat conducting belt is graphene or copper tape.

7. An augmented reality optical lens with an eye protection function according to any one of claims 1-6, characterized in that, The thickness of the infrared reflection layer facing the human eye direction is 100nm, and the thickness facing the environment direction is 10nm.

8. A method for preparing an augmented reality optical lens with an eye protection function according to any one of claims 1-7, characterized in that, Including: S00. Input the optimization objectives on the simulation software, including visible light transmittance and infrared radiation rate; S10. Input the initial structure, establish a model of the lens, optimize the thickness of each layer by using the simulation software, obtain the final optimized thickness of each layer of the lens, and obtain the final design value; S20. Use the thin film deposition method to deposit materials on the substrate in sequence according to the final design value.

9. The preparation method according to claim 8, characterized in that, Deposit materials on the substrate in sequence according to the final design value by electron beam evaporation coating or magnetron sputtering coating.

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