CN214252645U - Novel waveguide lens - Google Patents

Abstract

The utility model discloses a novel waveguide lens, be in including waveguide substrate, setting functional area on the waveguide substrate, the side of waveguide substrate each side all is equipped with the optimization layer that has absorption and reflection visible light. Through above-mentioned structure, avoid external environment light to penetrate through glass from the side effectively and get into inside the waveguide to and turn back once more after avoiding the interior light reflection of waveguide to the lateral wall, the diffraction region is gone into to the mistake, has reduced light interference's efficiency, thereby has improved display effect.

Description

Novel waveguide lens

Technical Field

The utility model relates to a AR shows technical field, especially relates to a novel waveguide lens.

Background

AR (Augmented Reality) is a new technology that skillfully integrates virtual information and the real world, i.e., information or images provided by a computer system are superimposed on real world information and presented to a user, thereby improving the perception of the user on the real world. An observer can view information such as images or data superimposed on a real environment while viewing an external real object, and thus the observer is widely applied to various fields, particularly military fields and consumer fields.

The key technologies for near-to-eye display of augmented reality mainly include an optical display technology and a micro-screen display technology, and the optical display technology is the largest factor for determining the volume and the display effect of display hardware, so that how to balance index parameters such as FOV, lightness and thinness, mass productivity and display quality is the prerequisite of primary consideration. The augmented reality optical display technology is developed to the present, the main schemes are roughly divided into a coaxial side-view prism scheme, an array type semi-permeable membrane waveguide scheme, a free-form surface scheme, a holographic grating waveguide scheme and the like, and the display performances of different schemes are different. The scheme of adopting the waveguide substrate is the optimal scheme which can take account of volume, lightness and thinness and FOV at present, but due to the adoption of the high-transmittance glass material and the diffraction characteristic of the waveguide substrate, stray light interference is easy to exist, and the display quality is influenced.

As shown in fig. 1, the incident light passes through the functional region to generate diffracted light, and when total reflection is satisfied, the light is continuously and totally reflected along the inside of the waveguide substrate and transmitted to the side surface of the waveguide substrate, and if the outside environment of the side surface of the waveguide substrate is air, the total reflected light is totally reflected by the side surface to return and transmit in the waveguide substrate, and if the returning light passes through the functional region, reflective diffraction is generated, and the light is interference light, which reduces the display quality.

As shown in fig. 2, the external ambient light comes from all directions, part of the light can be refracted through the side surface of the waveguide substrate and enter the waveguide substrate, and the light satisfying the total reflection angle can be transmitted by total reflection inside the waveguide substrate, if the transmitted light passes through the functional region, reflective diffraction can be generated, and the part of the light is interference light, which can reduce the display quality.

The foregoing description is provided for general background information and is not admitted to be prior art.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a reduce light interference efficiency's novel waveguide lens.

The utility model provides a novel waveguide lens, be in including waveguide substrate, setting functional area on the waveguide substrate, the side of waveguide substrate each side all is equipped with the optimization layer that has absorption and reflection visible light.

In one embodiment, the optimization layer is disposed on the side surface in a manner of plating, and the optimization layer covers the entire side surface.

In one embodiment, the optimization layer includes N metal layers and N-1 dielectric layers, N is not less than 2, wherein the metal layers and the dielectric layers are sandwiched, and the first layer and the last layer of the optimization layer are both metal layers.

In one embodiment, the N metal layers are made of the same or different materials, and the N-1 dielectric layers are made of the same or different materials.

In one embodiment, the metal layer is made of nickel, chromium or germanium, and the dielectric layer is made of silicon dioxide, titanium dioxide or silicon nitride.

In one embodiment, the optimization layer sequentially includes a first metal layer, a first dielectric layer, a second metal layer, a second dielectric layer, and a third metal layer, wherein the first metal layer is in contact with the side surface.

In one embodiment, the thickness of the first metal layer is 1nm to 20nm, the thickness of the first dielectric layer is 10nm to 100nm, the thickness of the second metal layer is 1nm to 20nm, the thickness of the second dielectric layer is 10nm to 50nm, and the thickness of the third metal layer is 1nm to 30 nm.

In one embodiment, the functional region includes a coupling-in region and a coupling-out region, the coupling-in region and the coupling-out region are etched on the waveguide substrate and are integrated with the waveguide substrate, or the coupling-in region and the coupling-out region are disposed on the surface of the waveguide substrate.

In one embodiment, the coupling-in region is provided with a plurality of first micro-nano structures, the coupling-out region is provided with a plurality of second micro-nano structures, and the first micro-nano structures and the second micro-nano structures are the same or different.

In one embodiment, the first micro-nano structures and the second micro-nano structures are one-dimensional grating structures or two-dimensional grating structures, a plurality of the first micro-nano structures are arrayed or arranged according to a certain period, and a plurality of the second micro-nano structures are arrayed or arranged according to a certain period.

The utility model provides a novel waveguide lens, through the side of waveguide substrate each side all is equipped with the optimization layer that has absorption and reflection visible light, avoids external environment light to see through inside getting into the waveguide substrate from the side effectively to and turn back once more after avoiding waveguide substrate internal light reflection to the lateral wall, the diffraction region is gone into to the mistake, has reduced light interference's efficiency, thereby has improved the display effect.

Drawings

FIG. 1 is a schematic diagram of light ray transmission of interference light inside a conventional waveguide substrate;

FIG. 2 is a schematic diagram of light transmission of ambient disturbance light outside a conventional waveguide substrate;

fig. 3 is a schematic structural diagram of a novel waveguide lens according to an embodiment of the present invention;

FIG. 4 is a schematic view of the structure of FIG. 3 from another perspective;

fig. 5 is a schematic view of light transmission inside a waveguide substrate according to an embodiment of the present invention;

fig. 6 is a schematic view of light transmission outside a waveguide substrate according to an embodiment of the present invention;

fig. 7 is a graph showing the spectral characteristics of the first experimental external light incident on the waveguide substrate 1 via the optimized layer according to the embodiment of the present invention;

FIG. 8 is a graph of the transmission spectral characteristics of a first experimental external light incident on a waveguide substrate through an optimization layer at an incident angle of 0-70 degrees;

fig. 9 shows spectral characteristics of the first experiment internal light after being incident on the optimized layer according to the embodiment of the present invention;

FIG. 10 is a graph of the reflection spectrum of the first experimental internal light incident on the optimization layer at an incident angle of 0-70 degrees according to the embodiment of the present invention;

FIG. 11 is a graph of the spectral characteristics of external light incident on a waveguide substrate via an optimized layer according to a second embodiment of the present invention;

fig. 12 is a graph of spectral characteristics of the second experimental internal light after incidence on the optimized layer according to the embodiment of the present invention;

FIG. 13 is a graph of the spectral characteristics of a third experimental external light incident on a waveguide substrate via an optimized layer according to the embodiment of the present invention;

fig. 14 is a graph of spectral characteristics of the third experiment internal light incident on the optimized layer according to the embodiment of the present invention;

fig. 15 is a graph showing the spectral characteristics of the external light incident on the waveguide substrate via the optimized layer according to the fourth embodiment of the present invention;

fig. 16 is a graph of spectral characteristics of the fourth experiment internal light after incidence on the optimization layer according to the embodiment of the present invention;

FIG. 17 is a graph showing the spectral characteristics of a fifth experimental external light incident on a waveguide substrate via an optimized layer according to an embodiment of the present invention;

fig. 18 is a spectral characteristic diagram of a fifth experimental internal light beam incident on the optimization layer according to an embodiment of the present invention.

Detailed Description

The following detailed description of the embodiments of the present invention is provided with reference to the accompanying drawings and examples. The following examples are intended to illustrate the invention, but are not intended to limit the scope of the invention.

Referring to fig. 3 and 4, the novel waveguide lens provided in the embodiment of the present invention includes a waveguide substrate 1 and a functional region 2 disposed on the waveguide substrate 1, wherein an optimization layer 3 having functions of absorbing and reflecting visible light is disposed on each side of the waveguide substrate 1.

The waveguide substrate 1 is square and is made of a material with high visible light transmittance; the refractive index of the waveguide substrate 1 is 1.5. The waveguide substrate 1 has a total reflection characteristic inside.

The functional region 2 includes a coupling-in region 21 and a coupling-out region 22. The coupling-in region 21 and the coupling-out region 22 are arranged on the surface of the waveguide substrate 1 on the same side.

In other embodiments, the functional region 2 is etched in the waveguide substrate 1 and is integral with the waveguide substrate 1. That is, the coupling-in region 21 and the coupling-out region 22 are etched in the waveguide substrate 1 and are integrated with the waveguide substrate 1.

The coupling-in area 21 is provided with a plurality of first micro-nano structures, the coupling-out area 22 is provided with a plurality of second micro-nano structures, and the first micro-nano structures and the second micro-nano structures are the same or different.

The first micro-nano structure and the second micro-nano structure are one-dimensional grating structures or two-dimensional grating structures. The plurality of first micro-nano structures are arrayed or arranged according to a certain period; the second micro-nano structures are arrayed or arranged according to a certain period. Specifically, the plurality of first micro-nano structures and the plurality of second micro-nano structures are arranged in an array, and the period range of the array is between 250 and 550nm, so that red, green and blue three-color waveband light can be modulated.

Specifically, image light enters the coupling-in area 21 of the waveguide substrate 1 from the outside, and is bent by array diffraction and reflection of the coupling-in area 21, so that the condition that the transmitted light totally reflected by the waveguide substrate 1 is transmitted to the coupling-out area 22 at a specific angle, and is transmitted by bending light such as diffraction and reflection of the coupling-out area 22 is met, part of light is diffracted and emitted, part of light is continuously transmitted, the light emitted to human eyes can enable an observer to watch a virtual image, and the continuously transmitted light can realize a pupil expanding function and expand an observation area.

The optimization layer 3 covers the whole side face in a film coating mode; the number of the optimization layers 3 is 4, and the optimization layers are respectively arranged on the side surfaces of the periphery of the waveguide substrate 1. The optimization layer 3 has a bidirectional optical interference prevention function; the bidirectional optical interference prevention function is as follows: when external environment light enters the waveguide substrate 1 from the side surface, the external environment light enters the waveguide substrate 1 after being absorbed and reflected by the optimized layer 3, and the light transmittance of the waveguide substrate is greatly reduced; meanwhile, the light in the waveguide substrate 1 is reflected to the side surface and then turned back again, and the optimized layer 3 is arranged on the side surface, so that the light reflectivity is greatly reduced, and the light is prevented from entering the functional area 2 by mistake to cause light interference. Specifically, as shown in fig. 5, the incident light passes through the functional region 2 of the waveguide substrate 1 to generate diffracted light, and when the total reflection is satisfied, the light is continuously and totally reflected along the inside of the waveguide substrate 1 and transmitted to the side surface of the waveguide substrate 1, and the light is absorbed, transmitted and reflected by the optimized layer 3; therefore, the reflection efficiency of the light after passing through the side face is reduced, namely, the light in the waveguide substrate 1 is prevented from being reflected to the side face and then turning back again, and the light reflectivity is greatly reduced. As shown in fig. 6, after external environment light enters the waveguide from the side of the waveguide substrate 1, the light will form stray light interference, but due to the optimized layer 3 on the side of the waveguide substrate 1, the light will be absorbed, transmitted and reflected by the optimized layer 3; thus, the transmission efficiency of the external ambient light is reduced, i.e., the external ambient light is prevented from entering the waveguide substrate 1 from the side of the waveguide substrate 1 to propagate.

The optimization layer 3 comprises N metal layers and N-1 dielectric layers, wherein N is an integer not less than 2; wherein, the metal layer and the dielectric layer are arranged in a sandwich manner, and the first layer and the last layer of the optimization layer 3 are both metal layers. The N metal layers are made of the same or different materials, and the N-1 dielectric layers are made of the same or different materials.

In one embodiment, when N is greater than 2, K layers of the N metal layers may be the same, K layers of the N-1 dielectric layers are the same, K is less than N, and K is an integer not less than 2.

Preferably, the optimization layer 3 sequentially includes a first metal layer 31, a first dielectric layer 32, a second metal layer 33, a second dielectric layer 34 and a third metal layer 35; wherein the first metal layer 31 is in contact with the side faces. The first metal layer 31, the first dielectric layer 32, the second metal layer 33, the second dielectric layer 34 and the third metal layer 35 are sequentially stacked on the side surface of the waveguide substrate 1 in a film coating manner to form the optimized layer 3.

The first metal layer 31, the second metal layer 33 and the third metal layer 35 are made of nickel, chromium or germanium; the first dielectric layer 32 and the second dielectric layer 34 are made of silicon dioxide, titanium dioxide or silicon nitride. The thickness of the first metal layer 31 is 1nm-20nm, the thickness of the first dielectric layer 32 is 10nm-100nm, the thickness of the second metal layer 33 is 1nm-20nm, the thickness of the second dielectric layer 34 is 10nm-50nm, and the thickness of the third metal layer 35 is 1nm-30 nm.

By carrying out strict coupled wave simulation calculation and solving Maxwell boundary conditions, the spectral characteristics of the light after passing through the optimization layer 3 can be calculated. The proper thickness and material of each layer are adjusted, so that different effects of the bidirectional optical interference prevention function can be realized. The following experiment was carried out.

First experiment

The first metal layer 31 is made of nickel and has a thickness of 5 nm; the first dielectric layer 32 is made of silicon nitride and has a thickness of 60 nm; the second metal layer 33 is made of nickel and has a thickness of 10 nm; the second dielectric layer 34 is made of silicon nitride and has a thickness of 20 nm; the third metal layer 35 is made of nickel and has a thickness of 12 nm.

As shown in fig. 7, the light is incident on the optimization layer 3 from the outside at an incident angle of 0 °, and it can be seen that the transmission efficiency of the visible light band is less than 15%, and the remaining light is partially absorbed and partially reflected, indicating that most of the light cannot enter the inside of the waveguide substrate 1 through the optimization layer 3 in the process.

For analysis of the transmission spectral characteristics at different angles of incidence, spectral curve simulations at angles of 0-70 ° and 25 ° apart were performed. As shown in fig. 8, it can be seen that, as the angle increases to 70 °, the transmission efficiency of the visible light band is still less than 20%, and the waveguide substrate has a transmission tolerance of a larger angle, that is, when external ambient light enters the waveguide substrate 1, the light transmittance is greatly reduced due to the side surface of the optimized layer 3, so that the problem of light interference caused by external transmitted light is reduced. The optimization layer 3 is arranged on the side surface of the periphery of the waveguide substrate 1, so that external environment light can be prevented from penetrating from the side surface to enter the waveguide substrate 1 as much as possible, and light in the waveguide substrate 1 can be prevented from being reflected to the side surface and then turning back again to enter the functional region 2 by mistake, so that light interference is caused. Namely, the optical fiber has a bidirectional optical interference prevention function.

As shown in fig. 9, the light is incident on the optimization layer 3 from the waveguide substrate 1 at an incident angle of 0 °, and it can be seen that the reflection efficiency of the visible light band is less than 10%, and the absorption efficiency is on average greater than 80%, indicating that most of the light is absorbed by the multiple magnetic field resonances due to the structure of the optimization layer 3 in the process.

For analysis of the reflection spectral characteristics at different angles of incidence, spectral curve simulations at angles of 0-70 ° and intervals of 25 ° were performed. As shown in fig. 10, it can be seen that, as the angle increases to 50 °, the reflection efficiency of the visible light band is still less than 10%, and when the angle increases to 70 °, the reflection efficiency of the visible light band is still less than 20%, which has a larger angle of reflection latitude, that is, when light in the waveguide substrate 1 is reflected to the side surface, the light reflectivity is greatly reduced due to the optimized layer 3 disposed on the side surface, so that the problem of light interference caused by the internal reflected light is reduced.

Second experiment

The first metal layer 31 is made of chromium and has a thickness of 5 nm; the first dielectric layer 32 is made of silicon nitride and has a thickness of 60 nm; the second metal layer 33 is made of chromium and has a thickness of 10 nm; the second dielectric layer 34 is made of silicon nitride and has a thickness of 20 nm; the third metal layer 35 is made of chromium and has a thickness of 12 nm.

As shown in fig. 11, the light is incident on the optimized layer 3 from the outside at an incident angle of 0 °, and it can be seen that the transmission efficiency of the visible light band is less than 5%, the rest of the light is partially absorbed and partially reflected, which indicates that most of the light cannot enter the inside of the waveguide through the optimized layer 3 in the process, and the transmission performance is better than that of the case where all the metal layers are nickel.

As shown in fig. 12, when light enters the optimized layer 3 in the waveguide substrate 1 at an incident angle of 0 °, it can be seen that the reflection efficiency of the visible light band is less than 10%, the absorption efficiency is averagely greater than 80%, and the reflection efficiency gradually decreases to approximately 0 as the wavelength increases from 400nm to 700nm, indicating that the optimized layer 3 has an extremely low reflection characteristic for the light reflected inside the waveguide substrate 1.

Third experiment

The first metal layer 31 is made of chromium and has a thickness of 5 nm; the first dielectric layer 32 is made of silicon nitride and has a thickness of 60 nm; the second metal layer 33 is made of nickel and has a thickness of 10 nm; the second dielectric layer 34 is made of silicon nitride and has a thickness of 20 nm; the third metal layer 35 is made of chromium and has a thickness of 12 nm.

As shown in fig. 13, when light enters the optimized layer 3 from the outside at an incident angle of 0 °, it can be seen that the transmission efficiency of the visible light band is less than 7%, and the remaining light is partially absorbed and partially reflected, indicating that in this process, most of the light cannot enter the waveguide substrate 1 through the optimized layer 3, and the transmission performance is better than that of the case where all the metal layers are nickel.

As shown in fig. 14, the light is incident on the optimized layer 3 from the inside of the waveguide substrate 1 at an incident angle of 0 °, and it can be seen that the reflection efficiency of the visible light band is less than 16%, the absorption efficiency is more than 80% on average, and the reflection efficiency gradually decreases to be close to 0 as the wavelength increases from 400nm to 700nm, indicating that the optimized layer 3 has an extremely low reflection characteristic for the light reflected from the inside of the waveguide substrate 1.

Fourth experiment

The first metal layer 31 is made of chromium and has a thickness of 5 nm; the first dielectric layer 32 is made of silicon dioxide and has a thickness of 60 nm; the second metal layer 33 is made of chromium and has a thickness of 10 nm; the second dielectric layer 34 is made of silicon dioxide and has a thickness of 20 nm; the third metal layer 35 is made of chromium and has a thickness of 12 nm.

As shown in fig. 15, when light enters the optimized layer 3 from the outside at an incident angle of 0 °, it can be seen that the transmission efficiency of the visible light band is less than 2%, the remaining light is partially absorbed and partially reflected, which indicates that almost all light cannot enter the waveguide substrate 1 through the optimized layer 3 in the process, and the transmission performance is better than that of the case where all metal layers are nickel and all dielectric layers are silicon nitride.

As shown in fig. 16, the light is incident on the optimized layer 3 from the inside of the waveguide substrate 1 at an incident angle of 0 °, and it can be seen that the reflection efficiency of the visible light band is less than 8%, and the absorption efficiency is on average greater than 90%, indicating that the optimized layer 3 has an extremely low reflection characteristic for the reflected light inside the waveguide substrate 1.

Fifth experiment

The first metal layer 31 is made of chromium and has a thickness of 5 nm; the first dielectric layer 32 is made of silicon dioxide and has a thickness of 60 nm; the second metal layer 33 is made of chromium and has a thickness of 10 nm; the second dielectric layer 34 is made of silicon nitride and has a thickness of 20 nm; the third metal layer 35 is made of chromium and has a thickness of 12 nm.

As shown in fig. 17, when light enters the optimized layer 3 from the outside at an incident angle of 0 °, it can be seen that the transmission efficiency of the visible light band is less than 5%, the remaining light is partially absorbed and partially reflected, which indicates that almost all light cannot enter the waveguide substrate 1 through the optimized layer 3 in the process, and the transmission performance is better than that of the case where each metal layer is nickel and each dielectric layer is silicon nitride.

As shown in fig. 18, when light is incident on the optimized layer 3 from the inside of the waveguide substrate 1 at an incident angle of 0 °, it can be seen that the reflection efficiency of the visible light band is less than 12%, the absorption efficiency is on average greater than 90%, and the reflection efficiency gradually decreases to be close to 0 as the wavelength increases from 400nm to 700nm, indicating that the optimized layer 3 has an extremely low reflection characteristic for the light reflected from the inside of the waveguide substrate 1.

In the drawings, the size and relative sizes of layers and regions may be exaggerated for clarity. It will be understood that when an element such as a layer, region or substrate is referred to as being "formed on," "disposed on" or "located on" another element, it can be directly on the other element or intervening elements may also be present. In contrast, when an element is referred to as being "directly formed on" or "directly disposed on" another element, there are no intervening elements present.

In this document, the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", "vertical", "horizontal", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for the sake of clarity and convenience of description of the technical solutions, and thus, should not be construed as limiting the present invention.

As used herein, the ordinal adjectives "first", "second", etc., used to describe an element are merely to distinguish between similar elements and do not imply that the elements so described must be in a given sequence, either temporally, spatially, in ranking, or in any other manner.

As used herein, the meaning of "a plurality" or "a plurality" is two or more unless otherwise specified.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

As used herein, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, including not only those elements listed, but also other elements not expressly listed.

The above description is only for the specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto, and any person skilled in the art can easily think of the changes or substitutions within the technical scope of the present invention, and all should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims (9)

1. The utility model provides a novel waveguide lens, its characterized in that includes the waveguide substrate, sets up functional area on the waveguide substrate, the side of waveguide substrate each side all is equipped with the optimization layer that has absorption and reflection visible light, the optimization layer includes N metal level and N-1 dielectric layer, and N is not less than 2, wherein, the metal level with the dielectric layer is sandwich setting, just the first layer and the last layer on optimization layer are the metal level.

2. The novel waveguide lens of claim 1, wherein the optimization layer is coated on the side surface, and the optimization layer covers the entire side surface.

3. The novel waveguide lens of claim 1, wherein the N metal layers are made of the same or different materials, and the N-1 dielectric layers are made of the same or different materials.

4. The novel waveguide lens of claim 1, wherein the metal layer is made of nickel, chromium or germanium, and the dielectric layer is made of silicon dioxide, titanium dioxide or silicon nitride.

5. The novel waveguide lens of claim 1, wherein the optimization layer comprises a first metal layer, a first dielectric layer, a second metal layer, a second dielectric layer, and a third metal layer in that order, wherein the first metal layer is in contact with the side surface.

6. The novel waveguide lens of claim 5, wherein the thickness of the first metal layer is 1nm to 20nm, the thickness of the first dielectric layer is 10nm to 100nm, the thickness of the second metal layer is 1nm to 20nm, the thickness of the second dielectric layer is 10nm to 50nm, and the thickness of the third metal layer is 1nm to 30 nm.

7. The novel waveguide lens of claim 1, wherein the functional region comprises a coupling-in region and a coupling-out region, the coupling-in region and the coupling-out region being etched into and integral with the waveguide substrate, or the coupling-in region and the coupling-out region being disposed on the waveguide substrate surface.

8. The novel waveguide lens of claim 7, wherein the coupling-in region is provided with a plurality of first micro-nano structures, the coupling-out region is provided with a plurality of second micro-nano structures, and the first micro-nano structures and the second micro-nano structures are the same or different.

9. The novel waveguide lens of claim 8, wherein the first micro-nano structures and the second micro-nano structures are one-dimensional grating structures or two-dimensional grating structures, a plurality of the first micro-nano structures are arrayed or arranged according to a certain period, and a plurality of the second micro-nano structures are arrayed or arranged according to a certain period.

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