Optical waveguide assembly and preparation method thereof, and AR display device

Abstract

The embodiment of the invention provides an optical waveguide assembly and a preparation method thereof, and an AR display device, the optical waveguide assembly comprises a waveguide sheet, protection lenses and an optical dielectric material uniformly filled between the waveguide sheet and the protection lenses, the protection lenses are respectively located at the upper and lower sides of the waveguide sheet, and the waveguide sheet and the protection lenses are integrated through the optical dielectric material. The refractive index of the waveguide sheet is larger than that of the optical medium material, and the refractive index relation between the waveguide sheet and the optical medium material meets the total reflection condition. According to the scheme, the optical waveguide can be prevented from being affected by dirt or scratches, the diopter of the protection lens can be adjusted according to user requirements, and the user experience is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of AR optical elements, and in particular to an optical waveguide component, a method for preparing the optical waveguide component, and an AR display device. Background Art

[0002] In augmented reality devices, array optical waveguides are usually composed of coupling structures, array beam splitters, waveguide substrates, etc., which are used to effectively transmit light to the user's eyes through total reflection in the optical waveguide and create virtual images or information on the display interface. When used, optical waveguides have high requirements for surface finish. Dust or dirt can cause refraction or scattering of light during propagation, thereby affecting the image quality. In addition, for users with myopia or hyperopia, they need to wear augmented reality devices on top of myopia glasses or hyperopia glasses, which increases the overall volume and weight, affecting the user experience.

[0003] The existing solution is to add a protective lens to the front and back surfaces of the waveguide, leaving a certain air gap between the protective lens and the upper and lower surfaces of the waveguide to meet the total reflection condition, or to add a diopter lens to the side of the waveguide close to the human eye, with an air gap between the lens and the waveguide. However, this solution will increase the volume and weight of the lens part, and may also cause the lens to deform due to external forces, making the middle air layer uneven, resulting in thick interference Newton ring optical interference phenomenon, affecting the user experience. Summary of the invention

[0004] In order to solve the problems existing in the background technology, this solution proposes an optical waveguide component, a method for preparing the optical waveguide component and an AR display device. By injecting a low-refractive index optical medium material into the air layer between the waveguide plate and the protective lens, total reflection propagation of light is achieved, so that the optical waveguide is not affected by dirt or scratches, and the refractive power of the protective lens can be adjusted according to user needs to improve user experience.

[0005] According to a first aspect of the present invention, there is provided an optical waveguide component, comprising a waveguide plate, a protective lens, and an optical dielectric material uniformly filled between the waveguide plate and the protective lens, wherein the protective lenses are respectively located on the upper and lower sides of the waveguide plate and are integrated into one by the optical dielectric material, the refractive index of the waveguide plate is greater than the refractive index of the optical dielectric material, and the refractive index relationship between the waveguide plate and the optical dielectric material satisfies the total reflection condition.

[0006] By adopting the above technical solution, by injecting a low-refractive-index optical medium material into the air layer between the waveguide and the protective lens, the refractive index of the waveguide is greater than that of the optical medium material, thereby achieving total reflection propagation of light, making the entire optical element unaffected by dirt or scratches, and preventing Newton rings from occurring between the waveguide and the protective lens.

[0007] Optionally, in the optical waveguide component provided by the present invention, the waveguide plate adopts a one-dimensional pupil expansion waveguide plate or a two-dimensional pupil expansion waveguide plate made of a high refractive index material including but not limited to lithium niobate and silicon carbide.

[0008] Optionally, in the optical waveguide component provided by the present invention, the waveguide sheet is an array optical waveguide or a diffraction optical waveguide.

[0009] Optionally, in the optical waveguide component provided by the present invention, the optical medium material is an optical film or optical glue.

[0010] Optionally, in the optical waveguide component provided by the present invention, the protective lens in the optical waveguide component is removable.

[0011] Optionally, in the optical waveguide assembly provided by the present invention, the protective lens on the side of the optical waveguide assembly close to the human eye is a refractive lens, and the refractive lens is a lens with adjustable focal length or a refractive lens configured according to the user's diopter.

[0012] By adopting the above technical solution, the diopter of the protective lens can be adjusted so that the user does not need to wear additional glasses or perform complicated vision calibration, or a lens matching the user's diopter can be directly configured to obtain a clear visual effect.

[0013] According to a second aspect of the present invention, a method for preparing an optical waveguide component is provided, comprising: selecting a substrate material having a first refractive index as a waveguide plate; uniformly coating an optical medium material having a second refractive index on the upper and lower surfaces of the waveguide plate, respectively, wherein the first refractive index is greater than the second refractive index, and the relationship between the first refractive index and the second refractive index satisfies a total reflection condition; and attaching protective lenses on the upper and lower surfaces of the optical medium material, respectively.

[0014] Optionally, in the method for preparing an optical waveguide component provided by the present invention, the protective lens on the side of the optical waveguide component close to the human eye is set as a refractive lens.

[0015] Optionally, in the method for preparing an optical waveguide assembly provided by the present invention, the refractive lens adopts a lens with adjustable focal length or a lens configured according to the user's diopter.

[0016] According to a third aspect of the present invention, there is provided an AR display device, comprising the optical waveguide component according to the first aspect of the present invention.

[0017] The optical waveguide assembly provided by the present invention can at least achieve the following technical effects: 1. By injecting low-refractive-index optical medium material between the waveguide and the protective lens, the refractive index difference between the waveguide and the glue layer interface causes the light to be totally reflected at this interface during propagation. In this way, defects such as dust, scratches or oil on the protective lens surface will not affect the light propagation, thereby improving the applicability of the optical waveguide component.

[0018] 2. By setting the protective lens on the side of the optical waveguide component close to the human eye as a refractive lens, users can obtain clear vision without wearing additional glasses or performing complex vision calibration, or directly configure lenses that match the user's refractive power. This not only makes the use of AR devices more convenient, but also improves the comfort of wearing AR devices.

[0019] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented according to the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Moreover, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings: Figure 1 This is a schematic structural diagram of an optical waveguide assembly according to Embodiment 1 of the present invention; Figure 2 is a schematic structural diagram of an optical waveguide assembly according to Embodiment 2 of the present invention; Figure 3 Schematic diagram of the structure of the optical waveguide component of Example 3 of the present invention. DETAILED DESCRIPTION

[0021] The principle of optical waveguide is to use the high refractive index of waveguide compared to air. For example, the refractive index of glass n1 is 1.52, and the refractive index of air n0 is 1. In order to meet the total reflection condition, the propagation angle of light in the waveguide needs to be greater than the total reflection angle, that is, θ>arcsin(n0 / n1)≈41.14°.

[0022] In order to solve the problem of poor imaging quality caused by surface dirt or pressure during light propagation, this solution provides an optical waveguide component. By injecting a low-refractive-index optical medium material between the waveguide plate and the protective lens, the refractive index relationship between the waveguide plate and the optical medium material meets the total reflection condition, which can reduce the adverse effects of dirt on the upper and lower surfaces of the waveguide on the AR display effect; by adjusting the diopter of the protective lens, users do not need to wear additional glasses or perform complex vision calibration, and can directly obtain clear visual effects by adjusting the protective lens. This not only makes the use of AR devices more convenient, but also improves the comfort of the device.

[0023] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0024] Embodiment 1: Figure 1 FIG. 1 is a schematic diagram of the structure of the optical waveguide component of Embodiment 1 of the present invention. Figure 1 As shown, a waveguide plate, a protective lens, and an optical dielectric material uniformly filled between the waveguide plate and the protective lens, the protective lenses are respectively located on the upper and lower sides of the waveguide plate, and are integrated into one through the optical dielectric material. The refractive index of the waveguide plate is greater than the refractive index of the optical dielectric material, and the refractive index relationship between the waveguide plate and the optical dielectric material satisfies the total reflection condition.

[0025] Among them, the waveguide sheet can be selected from materials with high optical transmission efficiency and low absorption loss, such as silicon-based optical waveguides, fluoride optical fibers, silicon optical waveguides or polymer optical waveguides, etc., which can reduce light loss and improve the transmission performance of the waveguide sheet. Different optical waveguide materials have different refractive index characteristics. In an embodiment of the present invention, the waveguide sheet uses a one-dimensional pupil expansion waveguide sheet or a two-dimensional pupil expansion waveguide sheet made of high refractive index materials including but not limited to lithium niobate (refractive index is 2.2) and silicon carbide (refractive index is 2.6~2.7).

[0026] The waveguide sheet is any type of an array optical waveguide and a diffraction optical waveguide, wherein the array optical waveguide propagates light through a channel and couples out light through multiple side-by-side waveguide layer channels, and the diffraction optical waveguide includes surface relief, volume holographic optical waveguide, etc., and a tiny diffraction structure (such as a micro two-dimensional or three-dimensional grating) is embedded in the optical waveguide to control the propagation direction of light, thereby realizing image display.

[0027] The optical medium material can be an optical film or an optical glue. For example, the optical glue can be a low-refractive index transparent adhesive, and the thickness of the glue layer applied is controlled within a precise range to ensure that the total reflection condition is strictly met. Assuming that the refractive index of the low-refractive index optical medium material is n0=1.4 and the refractive index of the waveguide is n1=2.7, when the light propagates inside the waveguide, as long as θ>arcsin(n0 / n1)≈31.23° is satisfied, the total reflection propagation of the interface between the waveguide and the glue can be achieved.

[0028] In an embodiment of the present invention, the material of the protective lens has good transparency and low optical loss, for example, transparent plastic (such as PMMA, PC) or glass material is used. The selection of these materials needs to take into account factors such as strength, transparency, scratch resistance and cost. In addition, the protective lens can be further coated with an anti-reflective coating to reduce the light loss caused by reflection and improve the overall optical transmission efficiency, especially in high-precision optical waveguide components, which can reduce the optical loss caused by reflection. Therefore, the protective lens and the waveguide plate are integrated into one by optical medium materials, which can solve the adverse effects of dirt on the optical waveguide display effect, and no Newton ring phenomenon will be generated between the waveguide plate and the protective lens.

[0029] Embodiment 2: Taking into account that the user's eyes have a certain degree of refractive problem, in order to meet the usage needs of different user groups (such as myopia, hyperopia or presbyopia, etc.), the protective lens on the side of the optical waveguide component close to the human eye can be set as a refractive lens. Figure 2 FIG. 2 is a schematic diagram of the structure of an optical waveguide component according to Embodiment 2 of the present invention. Figure 2 As shown, the optical waveguide assembly includes a waveguide sheet and an optical medium material uniformly coated on the upper and lower surfaces of the waveguide sheet, and the upper and lower surfaces of the optical medium material are respectively covered with protective lenses, and the protective lens on the side of the optical waveguide assembly close to the human eye is a refractive lens. The refractive lens is a lens with adjustable focal length or a refractive lens configured according to the user's diopter.

[0030] For example, the refractive lens adopts a liquid crystal lens with adjustable focal length. The introduction of the liquid crystal lens enables the optical waveguide component to achieve dynamic adjustment of the focal length, that is, by adjusting the electric field strength of the liquid crystal lens, the focal length change of the liquid crystal lens can be accurately controlled, thereby adjusting the focusing degree of the light, which can simplify multiple components in the traditional optical system (such as multiple optical lenses, automatic focusing mechanism, etc.), improve the system integration, thereby reducing the size and weight of the device and improving the user's wearing experience.

[0031] Embodiment 3: Figure 3 FIG. 3 is a schematic diagram of the structure of the optical waveguide component of Embodiment 3 of the present invention. Figure 3 As shown, the optical waveguide assembly includes a waveguide sheet and an optical medium material uniformly coated on the upper and lower surfaces of the waveguide sheet. Similarly, the refractive index of the waveguide sheet is greater than the refractive index of the optical medium material, and the refractive index relationship between the waveguide sheet and the optical medium material satisfies the total reflection condition. That is, the protective lens in embodiments 1 and 2 can be set to be removable. For example, by removing the protective lens on the side of the optical waveguide assembly close to the human eye, it can be replaced with a lens that matches the user's diopter.

[0032] According to one embodiment of the present invention, a method for preparing an optical waveguide component is also provided, which specifically includes: selecting a substrate material with a first refractive index as a waveguide plate; uniformly coating an optical medium material with a second refractive index on the upper and lower surfaces of the waveguide plate, respectively, wherein the first refractive index is greater than the second refractive index, and the relationship between the first refractive index and the second refractive index satisfies the total reflection condition. For example, if the second refractive index of the low-refractive-index optical medium material is n0=1.4, and the first refractive index of the waveguide plate is n1=2.7, then when the light propagates inside the waveguide, as long as θ>arcsin(n0 / n1)≈31.23° is satisfied, total reflection propagation at the interface between the waveguide plate and the glue can be achieved.

[0033] The optical waveguide component structure of Example 1 can be obtained through the above steps. Among them, the waveguide plate can be selected from materials with high optical transmission efficiency and low absorption loss, such as silicon-based optical waveguides, fluoride optical fibers, silicon optical waveguides or polymer optical waveguides, etc., which can reduce light loss and improve the transmission performance of the waveguide plate. Different optical waveguide materials have different refractive index characteristics. In the embodiment of the present invention, the waveguide plate adopts a one-dimensional pupil expansion or two-dimensional pupil expansion waveguide plate made of high refractive index materials including but not limited to lithium niobate (refractive index is 2.2) and silicon carbide (refractive index is 2.6~2.7).

[0034] The optical medium material is an optical film or optical glue with a low refractive index. Assuming that the refractive index of the low refractive index optical medium material is n0=1.4 and the refractive index of the waveguide is n1=2.7, when the light propagates inside the waveguide, as long as θ>arcsin(n0 / n1)≈31.23° is satisfied, total reflection propagation at the interface between the waveguide and the glue can be achieved.

[0035] Subsequently, protective lenses are attached to the upper and lower surfaces of the optical medium material, and the protective lens on the side of the optical waveguide component close to the human eye is a refractive lens. The refractive lens uses a liquid crystal lens with adjustable focal length, and the electric field applied to the liquid crystal lens is adjusted according to the required refractive adjustment parameters to adjust the focal length of the optical waveguide component.

[0036] In an embodiment of the present invention, the material of the protective lens has good transparency and low optical loss, for example, transparent plastic (such as PMMA, PC) or glass material is used. The selection of these materials needs to take into account factors such as strength, transparency, scratch resistance and cost. In addition, the protective lens can be further coated with an anti-reflective coating to reduce the light loss caused by reflection and improve the overall optical transmission efficiency, especially in high-precision optical waveguide components, which can reduce the optical loss caused by reflection. Therefore, the protective lens and the waveguide plate are integrated into one by optical medium materials, which can solve the adverse effects of dirt on the optical waveguide display effect, and no Newton ring phenomenon will be generated between the waveguide plate and the protective lens.

[0037] Refractive lenses use lenses with adjustable focal length or lenses configured according to the user's diopter. When using a liquid crystal lens with adjustable focal length, the focal length change of the liquid crystal lens can be accurately controlled by adjusting the electric field strength of the liquid crystal lens, thereby adjusting the focusing degree of the light, which can simplify multiple components in the traditional optical system (such as multiple optical lenses, automatic focusing mechanisms, etc.), improve the system's integration, thereby reducing the size and weight of the device and improving the user's wearing experience.

[0038] The optical waveguide assembly provided by the present invention can be applied to AR display devices, so that AR glasses can be wiped like ordinary glasses, and even if slight scratches or dirt are produced, it will not affect the display effect. The entire waveguide assembly can be the same as ordinary glasses, without the need for flat glass, which is more conducive to the design of glasses. In addition, the optical waveguide assembly can adjust the refractive power of the protective lens to match the refractive power required by the user, without the need to wear additional myopic or hyperopic glasses, which can improve the wearing effect of the AR display device.

[0039] The optical waveguide assembly provided by the present invention can at least achieve the following technical effects: 1. By injecting low-refractive-index optical medium material between the waveguide and the protective lens, the refractive index difference between the waveguide and the glue layer interface causes the light to be totally reflected at this interface during propagation. In this way, defects such as dust, scratches or oil on the protective lens surface will not affect the light propagation, thereby improving the applicability of the optical waveguide component.

[0040] 2. By setting the protective lens on the side of the optical waveguide component close to the human eye as a refractive lens, users can obtain clear vision without wearing additional glasses or performing complex vision calibration, or directly configure lenses that match the user's refractive power. This not only makes the use of AR devices more convenient, but also improves the comfort of wearing AR devices.

[0041] In the description provided herein, a large number of specific details are described. However, it is understood that embodiments of the present invention can be practiced without these specific details. In some instances, well-known methods, structures and techniques are not shown in detail so as not to obscure the understanding of this description.

[0042] As used herein, unless otherwise specified, the use of ordinal numbers "first," "second," "third," etc. to describe common objects merely indicates that different instances of similar objects are involved, and is not intended to imply that the objects so described must have a given order in time, space, order, or in any other manner.

Claims

1. An optical waveguide component, characterized in that: It includes a waveguide plate, a protective lens, and an optical medium material uniformly filled between the waveguide plate and the protective lens. The protective lenses are respectively located on the upper and lower sides of the waveguide plate and are integrated into one by the optical medium material. The refractive index of the waveguide plate is greater than the refractive index of the optical medium material, and the refractive index relationship between the waveguide plate and the optical medium material meets the total reflection condition.

2. The optical waveguide assembly according to claim 1, characterized in that The waveguide plate adopts a one-dimensional pupil expansion waveguide plate or a two-dimensional pupil expansion waveguide plate made of a high refractive index material including but not limited to lithium niobate and silicon carbide.

3. The AR display device according to claim 1, characterized in that: The waveguide sheet is an array optical waveguide or a diffraction optical waveguide.

4. The optical waveguide assembly according to claim 1, wherein: The optical medium material is an optical film or optical glue.

5. The optical waveguide assembly according to claim 1, wherein: The protective lens is removable.

6. The optical waveguide assembly according to claim 5, characterized in that The protective lens on the side of the optical waveguide component close to the human eye is a refractive lens, and the refractive lens is a lens with adjustable focal length or a refractive lens configured according to the user's diopter.

7. A method for preparing an optical waveguide component, characterized in that: include: Selecting a substrate material having a first refractive index as a waveguide; An optical medium material having a second refractive index is uniformly coated on the upper and lower surfaces of the waveguide plate, respectively, the first refractive index is greater than the second refractive index, and the relationship between the first refractive index and the second refractive index satisfies a total reflection condition; Protective lenses are respectively attached to the upper and lower surfaces of the optical medium material.

8. The method for preparing an optical waveguide component according to claim 7, characterized in that: The method further comprises: The protective lens on the side of the optical waveguide component close to the human eye is set as a refractive lens.

9. The method for preparing an optical waveguide component according to claim 8, characterized in that: The refractive lens adopts a lens with adjustable focal length or a lens configured according to the user's diopter.

10. An AR display device, characterized in that: Comprising an optical waveguide component as claimed in any one of claims 1 to 6.

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