Augmented reality optical lens with eye protection function and preparation method thereof

Abstract

The invention provides an augmented reality optical lens with an eye protection function and a preparation method thereof, and aims to solve the problems of heat dissipation and eye protection of head-mounted display equipment, silicon carbide is used as a substrate, and specific optical film structures are arranged on the two sides of the substrate. When the equipment emits heat, the heat conduction belt is connected with the heating element and the lens, heat is dissipated by means of thermal conductivity of silicon carbide, heat dissipation is enhanced by means of air heat exchange and infrared radiation direction regulation, and human eyes are prevented from being radiated by heat. The infrared radiation layer of the optical thin film controls the multi-band light transmittance, and the function of preventing ultraviolet and blue light is achieved. The head-mounted device integrates heat dissipation and eye protection functions, is simple in process and high in yield, meets the requirements of miniaturization, long endurance and eye protection of the head-mounted device, improves the user experience, and promotes the development of augmented reality technical equipment.

Description

Technical Field

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

[0002] In the process of the booming development of mixed reality technology, head-mounted display devices have an increasing number of internal electronic components to meet the needs of functional integration, resulting in a large amount of heat accumulation when the device is running. Heat dissipation has become a key challenge because it is in direct contact with human skin and has strict heat dissipation requirements.

[0003] Traditional heat dissipation methods mainly include fan heat dissipation and metal frame / heat sink heat dissipation. Although fan heat dissipation can actively dissipate heat, it significantly increases the size and weight of the device. The additional power consumption causes the battery life to decrease, which is contrary to the pursuit of miniaturization and long battery life of head-mounted devices. Although metal heat sinks can conduct heat, as additional components, they increase the load on the device and reduce wearing comfort. Although the metal frame can conduct some heat, the effective convection area is limited, and direct contact must be avoided to prevent skin burns, which greatly reduces the heat dissipation effect.

[0004] In order to resolve 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 thermal radiation and visible light transmittance to improve heat dissipation efficiency (as shown in patent CN116857844A). However, this solution coats the same radiation enhancement film on both sides of the silicon carbide lens, causing the human eye to be exposed to infrared thermal radiation with an emissivity of up to 60% when used for a long time. Due to the strong penetrating power of infrared radiation, fragile tissues such as the human cornea are heated and accumulated, which can cause irreversible damage. In addition, augmented reality glasses are worn in many daily scenarios and should have UV and blue light protection functions. The existing technology is lacking in the comprehensive eye protection level and cannot meet users' demands for improved equipment protection and wearing comfort.

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

[0006] The embodiments of the present invention provide an augmented reality optical lens with eye protection function and a preparation method thereof, in view of the shortcomings of the heat dissipation technology of head-mounted display devices in the current technology. Although silicon carbide lenses can dissipate heat, the same film is plated on both sides, causing damage to the human eyes by strong infrared thermal radiation, and lacks ultraviolet and blue light protection functions, and cannot meet the problems of device miniaturization, long battery life and comprehensive eye protection.

[0007] The core technology of this invention is mainly based on silicon carbide, a material with high thermal conductivity. An optical film is deposited on the surface of the material to increase the infrared emissivity and visible light transmittance. At the same time, it is designed to block blue light and control the direction of thermal radiation, so that it can be used as the lens of augmented reality glasses.

[0008] In a first aspect, the present invention provides an augmented reality optical lens with an eye protection function, comprising: Based on a substrate made of silicon carbide material, optical thin film structures are respectively arranged on both sides of the substrate; The optical film structure on the side facing the human eye is an infrared radiation layer, an infrared reflection layer, and a low refractive index medium layer in sequence; the optical film structure on the side facing the environment is an infrared reflection layer and an infrared radiation layer in sequence; A heat-conducting belt, one end of which is heat-conductingly connected to the lens, and the other end is located outside the lens and is used to connect to the heating element; When the device generates heat, the heating element is connected to the lens through a heat-conducting belt, and the heat is distributed to the lens using the thermal conductivity of silicon carbide, and heat is exchanged with the surrounding air to dissipate heat. In addition, optical films are used outdoors to control the direction of infrared radiation, so that the heat is radiated in the opposite direction of the human eye in the atmospheric window band. The infrared radiation layer has an infrared radiation rate facing the environment of more than 0.5 in the atmospheric window band, and an infrared radiation rate facing the human eye of less than 0.6 in the atmospheric window band. At the same time, the transmittance is more than 0.55 in the 455nm-700nm range, and the transmittance in the 200-380nm wavelength range is no more than 0.7, 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.

[0009] Furthermore, the infrared reflection layer adopts an optical thin film material with high transmittance in the visible light range and a reflectivity of more than 50% in the atmospheric window band.

[0010] Furthermore, the infrared radiation layer adopts a film layer structure of 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.

[0011] Furthermore, the low refractive index medium layer facing the human eye is magnesium fluoride.

[0012] Furthermore, the infrared reflection layer is made of indium tin oxide.

[0013] Furthermore, 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.

[0014] Furthermore, the thermal conductive tape is graphene or copper tape.

[0015] Furthermore, the thickness of the infrared reflection layer in the direction toward human eyes is 100 nm, and the thickness in the direction toward the environment is 10 nm.

[0016] In a second aspect, the present invention provides a method for preparing an augmented reality optical lens with an eye protection function, comprising: S00, input optimization objectives into the simulation software, including visible light transmittance and infrared radiation rate; S10, inputting the initial structure, establishing a lens model, optimizing the thickness of each layer using simulation software, obtaining the final optimized thickness of each layer of the lens, and obtaining the final design value; S20, using a thin film deposition method, depositing materials on the substrate in sequence according to the final design values.

[0017] The main contributions and innovations of the present invention are as follows: 1) Infrared thermal radiation protection: This invention precisely controls the direction of thermal radiation, and uses a unique optical film structure to set differentiated film layers on both sides of the silicon carbide lens. The side facing the human eye effectively blocks the heat generated by the equipment, and directs the infrared radiation out of the eye. Compared with the existing technology of double-sided coating with the same film, which causes 60% radiation rate to damage the eye, it greatly reduces the risk of cumulative heat exposure to the human eye, protects fragile tissues such as the cornea, and ensures the physiological function of the eye.

[0018] 2) Blue light and UV protection: The infrared radiation layer of the optical film also has anti-ultraviolet and blue light properties, blocking more than 40% of blue light at 380-455nm (specific structures block more than 45%), and controlling the UV transmittance at 200-380nm to below 0.5, preventing aging and lesions of the eye structure, improving visual health, expanding the daily wearing time of reality glasses, and filling the gaps in existing eye protection technology.

[0019] 3) Efficient passive heat dissipation: Silicon carbide lenses are combined with heat conducting tapes to build an efficient heat conduction path, quickly expanding the heat of components exceeding 60°C to the lenses. Using natural convection between the lenses and low-temperature air, based on the principles of aerodynamics and heat exchange, a stable heat dissipation flow is formed to improve heat dissipation efficiency, reduce the risk of heat loss of equipment, reduce dependence on active heat dissipation components such as fans, avoid increasing the size and weight of the equipment and power consumption, and ensure that the head-mounted device is compact, lightweight and has a long battery life.

[0020] 4) Enhanced heat dissipation through thermal radiation: With the help of optical films, infrared radiation in the atmospheric window (8-14μm) band is precisely controlled to increase the radiation efficiency of the lens to the environment, and heat is efficiently discharged to the low-temperature area of ​​outer space (about 3K). Compared with the existing limited heat dissipation technology, it expands the heat dissipation dimension, improves the heat dissipation power, ensures the stable operation of the equipment under high load, and provides an innovative solution to the heat dissipation problem of highly integrated functional modules.

[0021] 5) High visible light transmittance: The optical film layer has been optimized in design and refined in process to improve the lens transmittance in the visible light band of 400-700nm, ensuring the clarity and color fidelity of augmented reality scene images, enhancing the user's visual immersion and interactive experience, and leading in the balance between optical performance and functional integration.

[0022] 6) Excellent process: From the precise design of film 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, high yield rate, and is suitable for mass production, which reduces manufacturing costs, shortens production cycles, accelerates product launch and promotion, and enhances market competitiveness.

[0023] The details of one or more embodiments of the invention are set forth in the following drawings and description so that other features, objects, and advantages of the invention are more readily apparent. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary 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: Figure 1 is a schematic structural diagram of an augmented reality optical lens with an eye protection function according to an embodiment of the present invention; Figure 2 is a graph of infrared radiation rate of an augmented reality optical lens with eye protection function toward the environment according to an embodiment of the present invention; Figure 3 is a curve diagram of infrared radiation rate of an augmented reality optical lens with eye protection function toward human eyes according to an embodiment of the present invention; Figure 4 is a simulated visible light transmittance curve according to an embodiment of the present invention; Figure 5 is an infrared emissivity map toward the environment obtained by actual measurement according to an embodiment of the present invention; Figure 6 is a graph of infrared radiance toward human eyes actually measured according to an embodiment of the present invention; Figure 7 is a visible light transmittance curve actually measured according to an embodiment of the present invention. DETAILED DESCRIPTION

[0025] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with one or more embodiments of this specification. Instead, 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.

[0026] It should be noted that: in other embodiments, the steps of the corresponding method are not necessarily performed 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 be combined into a single step for description in other embodiments.

[0027] The prior art CN116857844A has the same radiation enhancement film coated on both sides of the silicon carbide lens, which causes the human eye to be exposed to long-term infrared heat radiation, with an emissivity of up to 60%. Infrared radiation has a strong penetrating ability. At the same time, the human eye is different from the skin. The relatively fragile biological structures such as the cornea will cause irreversible damage to the human eye due to the heat accumulation generated by infrared radiation. In addition, even augmented reality glasses, since they can be worn daily, should also meet the functions of anti-ultraviolet and blue light, provide users with higher protection and wearing comfort, and prevent blue light damage caused by electronic products.

[0028] Based on this, the present invention solves the problems existing in the prior art based on a new technical solution. The solution of the present invention is based on silicon carbide, a material with high thermal conductivity, and deposits an optical film on the surface of the material to achieve the effect of increasing infrared radiation rate and visible light transmittance, while preventing blue light and controlling the direction of thermal radiation, so as to serve as the lenses of augmented reality glasses.

[0029] Embodiment 1 The present invention aims to provide an augmented reality optical lens with eye protection function, specifically, referring to Figure 1 , including a substrate, an optical film structure and a thermal conductive tape. The optical film structure is arranged on both sides of the substrate to form a silicon carbide lens. One end of the thermal conductive tape is adhered to the lens through a thermal conductive adhesive, and the other end is located outside the lens for connecting a heating element.

[0030] The specific solution is that when the augmented reality glasses generate heat due to the operation of highly integrated components (usually above 60°C), the heating element is connected to the silicon carbide lens through a heat-conducting tape (generally a material with high thermal conductivity such as graphene or copper tape), and the heat generated by the electronic components is distributed to the entire lens using the ultra-high thermal conductivity of silicon carbide, thereby obtaining a larger convection area and more efficient heat exchange with the surrounding air at a lower temperature to achieve the purpose of heat dissipation. At the same time, under outdoor conditions, the optical film structure deposited on silicon carbide is used to regulate the infrared emissivity, so that it radiates more strongly in the atmospheric window (8-14μm) band and only in the opposite direction of the human eye, so that the heat can be radiated to the outer space with extremely low temperature (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 film structure on the silicon carbide lens can effectively filter blue light to protect the human eye.

[0031] More specifically, Figure 1 As shown, the silicon carbide lens includes a substrate, an infrared reflection layer, an infrared radiation layer, and a low refractive index medium layer. For the interface of the silicon carbide lens facing the human eye, the structure of the optical film is a substrate, an infrared radiation layer, an infrared reflection layer, and a low refractive index medium layer, while for the interface facing the environment, the structure of the optical film is a substrate, an infrared reflection layer, and an infrared radiation layer in sequence.

[0032] In this embodiment, the infrared reflection layer is an optical film with high transmittance in the visible light range and a reflectance of more than 50% in the atmospheric window band, such as indium tin oxide, which has the properties of visible light transparency and infrared reflection and is a good infrared reflection layer material, but is not limited to indium tin oxide; its function is to maintain high transmittance in the visible light range, further improve the infrared radiation rate at the interface facing the environment, and at the interface facing the human eye, the infrared reflection layer on the outside of the infrared radiation layer blocks the heat emitted by the infrared radiation to prevent radiation to the human eye; the atmospheric window band is between 8-13um.

[0033] In this embodiment, the infrared radiation layer refers to the infrared radiation rate facing the environment reaching more than 0.5 in the atmospheric window band, while the infrared radiation rate facing the human eye is less than 0.5 in the atmospheric window band. In addition, the transmittance is very high at 455nm-700nm, reaching more than 0.65; it produces an anti-ultraviolet effect, that is, the transmittance does not exceed 0.5 in the wavelength range of 200-380nm, and at the same time, it has an anti-blue light effect, that is, it blocks more than 40% of 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 the transmittance and reflectivity can be regulated. For example, for the anti-reflection film in the present invention, by adjusting the thickness of the film layer, this structure can control the constructive interference of the transmitted light and the destructive interference of the reflected light, thereby increasing the transmittance of the light. For the infrared radiation layer facing the environment, the film material needs to have absorption in the atmospheric window band in addition to meeting the refractive index requirements, so as to achieve the purpose of increasing infrared radiation. For example, titanium dioxide, hafnium dioxide, etc. are used for high refractive index materials, and silicon dioxide, etc. are used for low refractive index materials. The low refractive index medium layer facing the human eye can be magnesium fluoride, because it has a low refractive index and does not have the ability to enhance radiation in the infrared band.

[0034] Preferably, the infrared radiation layer adopts a film layer structure of 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.

[0035] Preferably, the substrate thickness is 0.2-4 mm, the infrared reflection layer has 1-10 layers, each layer has a thickness of 5-500 nm; the infrared radiation layer has 4-50 layers, each layer has a thickness of 5-500 nm; the low refractive index medium layer has a thickness of 5-500 nm; In this embodiment, the infrared reflection layer uses indium tin oxide, with a thickness of 100nm toward the human eye and 10nm toward the environment; the infrared radiation layer uses silicon dioxide and hafnium dioxide as low refractive index materials and high refractive index materials respectively, and the low refractive index medium layer uses magnesium fluoride. The film layer structure and thickness from the environment to the human eye are shown in Table 1 below (used to show the specific film system structure in the specific embodiment, specifically the thickness and material of each layer): Table 1 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

[0036] The radiation protection function characteristics achieved by the structure of the present invention are: Figure 2 and Figure 3The radiation rate towards the environment and the radiation rate towards the human eye are shown respectively. The UV protection and blue light protection functional characteristics achieved by the present invention are measured and calculated. The transmittance in the 200-380nm band is less than 0.37, and in the 380-455nm blue light band, 45% of harmful blue light is effectively blocked. Figure 4 For the simulated visible light transmittance curve, Figure 5 is the infrared radiation rate toward the environment obtained by actual measurement, Figure 6 is the actual measured infrared radiation rate toward the human eye, Figure 7 It is the visible light transmittance curve actually measured.

[0037] Embodiment 2 Based on the same concept, the present invention also proposes a method for preparing an augmented reality optical lens with eye protection function, comprising: S00, input optimization objectives into the simulation software, including visible light transmittance and infrared radiation rate; S10, inputting the initial structure, establishing a lens model, optimizing the thickness of each layer using simulation software, obtaining the final optimized thickness of each layer of the lens, and obtaining the final design value; S20, using a thin film deposition method, depositing materials on the substrate in sequence according to the final design values.

[0038] Preferably, the materials are sequentially deposited on the substrate according to the final design values ​​by electron beam evaporation coating or magnetron sputtering coating.

[0039] Those skilled in the art should understand that the technical features of the above embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0040] The above embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present invention. It should be pointed out that, for those of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the attached claims.

Claims

1. An augmented reality optical lens with eye protection function, characterized in that: include: A substrate made of silicon carbide material, with optical thin film structures arranged on both sides of the substrate; The optical film structure on the side facing the human eye is an infrared radiation layer, an infrared reflection layer, and a low refractive index medium layer in sequence; the optical film structure on the side facing the environment is an infrared reflection layer and an infrared radiation layer in sequence; A heat-conducting belt, one end of which is heat-conductingly connected to the lens, and the other end is located outside the lens and is used to connect to the heating element; When the device generates heat, the heating element is connected to the lens through a heat-conducting belt, and the heat is distributed to the lens using the thermal conductivity of silicon carbide, and heat is exchanged with the surrounding air to dissipate heat. In addition, optical films are used outdoors to control the direction of infrared radiation, so that the heat is radiated in the opposite direction of the human eye in the atmospheric window band. The infrared radiation layer has an infrared radiation rate facing the environment of more than 0.5 in the atmospheric window band, and an infrared radiation rate facing the human eye of less than 0.6 in the atmospheric window band. At the same time, the transmittance is more than 0.55 in the range of 455nm-700nm, and the transmittance in the wavelength range of 200-380nm does not exceed 0.7, and blocks more than 5% of blue light between 380-455nm; the atmospheric window band of the infrared reflection layer is between 8-14um.

2. The augmented reality optical lens with eye protection function as claimed in claim 1, characterized in that: The infrared reflection layer is made of an optical film material with high transmittance in the visible light range and a reflectivity of more than 50% in the atmospheric window band.

3. The augmented reality optical lens with eye protection function as claimed in claim 1, characterized in that: The substrate has a thickness of 0.2-4 mm.

4. The augmented reality optical lens with eye protection function as claimed in claim 1, characterized in that: The low refractive index medium layer facing the human eye is magnesium fluoride, and the thickness is 5-500nm.

5. The augmented reality optical lens with eye protection function as claimed in claim 2, characterized in that: The infrared reflection layer is made of indium tin oxide, with 1 to 10 layers and each layer having a thickness of 5 to 500 nm.

6. The augmented reality optical lens with eye protection function as claimed in claim 3, characterized in that: The infrared radiation layer adopts a film layer structure of alternating high and low refractive index materials, wherein the high refractive index material is titanium dioxide or hafnium dioxide, and the low refractive index material is silicon dioxide. The total number of alternating film layers is 4-50, and the thickness of each layer is 5-500nm.

7. The augmented reality optical lens with eye protection function as claimed in claim 1, characterized in that: The thermal conductive tape is graphene or copper tape.

8. An augmented reality optical lens with eye protection function as claimed in any one of claims 1 to 7, characterized in that: The thickness of the infrared reflection layer toward the human eye is 100 nm, and the thickness toward the environment is 10 nm.

9. A method for preparing an augmented reality optical lens with eye protection function as claimed in any one of claims 1 to 8, characterized in that: include: S00, input optimization objectives into the simulation software, including visible light transmittance and infrared radiation rate; S10, inputting the initial structure, establishing a lens model, optimizing the thickness of each layer using simulation software, obtaining the final optimized thickness of each layer of the lens, and obtaining the final design value; S20, using a thin film deposition method, depositing materials on the substrate in sequence according to the final design values.

10. The preparation method according to claim 9, characterized in that: The materials are deposited on the substrate in sequence according to the final design values ​​by electron beam evaporation coating or magnetron sputtering coating.

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