CN117148593B

CN117148593B - AR device

Info

Publication number: CN117148593B
Application number: CN202311422242.5A
Authority: CN
Inventors: 邓家裕; 蒋厚强; 朱以胜
Original assignee: Shenzhen Guangzhou Semiconductor Technology Co ltd
Current assignee: Shenzhen Guangzhou Semiconductor Technology Co ltd
Priority date: 2023-10-31
Filing date: 2023-10-31
Publication date: 2024-02-20
Anticipated expiration: 2043-10-31
Also published as: CN117148593A

Abstract

The application provides an AR device relates to AR technical field, includes: the optical axis of the optical machine is parallel to the optical waveguide or is arranged at a preset inclination angle, the orthogonal reflector array is arranged at a first included angle alpha with the optical axis of the optical machine, a grating is arranged on one surface of the optical waveguide facing the orthogonal reflector array, and light rays emitted by the optical machine are reflected to the grating after passing through the orthogonal reflector array and are coupled into the optical waveguide by the grating. The light is emitted from the optical machine, reflected to the grating after entering the orthogonal reflector array, and coupled into the optical waveguide by the grating for propagation. The orthogonal reflector array is adopted, so that the emergent light spot area of light rays passing through the orthogonal reflector array can be reduced, the light spot area when reaching the entrance pupil is smaller than or equal to the area of the entrance pupil, and the coupling efficiency is maximum=1; the light energy loss from the light emitted by the optical engine to the entrance pupil is effectively reduced, so that the heating of the equipment is reduced, the display brightness of an image is improved, and the performance of the AR device is enhanced.

Description

AR device

Technical Field

The application relates to the technical field of AR, in particular to an AR device.

Background

In Augmented Reality (AR) devices, the design and placement of the optics are key factors, which directly affect the volume, efficiency and user experience of the device. Conventional opto-mechanical designs often employ longitudinal placement, but the need for lateral placement is increasing due to space constraints and compactness requirements of the device.

After the light engine is placed laterally, a mirror is usually placed in front of the entrance pupil to reflect the light into the entrance pupil in order to direct the light from the entrance pupil into the waveguide. However, turning the optical path by a mirror has the disadvantage that the spot area upon passing the mirror to the entrance pupil is typically too large to exceed the entrance pupil area, as shown in fig. 1. Coupling efficiency at the entrance pupil = entrance pupil area/spot area (note: when the spot area is equal to or smaller than the entrance pupil area, the coupling efficiency is theoretically 1), it can be seen that if the spot area exceeds the entrance pupil area by a large amount, the coupling efficiency is low, and the brightness of the image is reduced. More seriously, the loss of light energy is converted into heat, resulting in heating of the device, which not only affects the stability and lifetime of the device, but may also negatively affect the user experience.

Disclosure of Invention

An object of the embodiments of the present application is to provide an AR device capable of improving coupling efficiency while maintaining compactness of an optical machine.

In one aspect of the embodiments of the present application, an AR device is provided, including an optical engine, an orthogonal mirror array and an optical waveguide, where an optical axis of the optical engine and the optical waveguide are parallel or set at a preset inclination angle, the orthogonal mirror array and the optical axis of the optical engine are set at a first included angle α, the optical waveguide faces to one surface of the orthogonal mirror array, and light emitted by the optical engine is reflected to the optical waveguide after passing through the orthogonal mirror array, and is coupled into the optical waveguide by the optical waveguide.

Optionally, the optical machine and the grating are respectively located at two sides of the orthogonal mirror array.

Optionally, the vector relationship among the optomachine, the orthogonal mirror array and the grating satisfies: (r1+r2) x n=0, where r1 is a wave vector of light emitted by the optical machine, r2 is a wave vector of incident light of the grating, n is a normal vector of the orthogonal mirror array, a component of the normal vector n on the x axis is sin α, a component on the y axis is sin θ, and θ is an included angle between the orthogonal mirror array and the y axis.

Optionally, the first included angle alpha is less than or equal to 20 degrees and less than or equal to 70 degrees, and the third included angle theta is less than or equal to 30 degrees and less than or equal to 30 degrees.

Optionally, the light machine emits light in a first direction and light in a second direction, and an included angle between the light in the first direction and the light in the second direction forms an angle of view of light emitted by the light machine; the sum of the first included angle alpha and the half field angle gamma of the optical machine is smaller than 90 degrees; the orthogonal reflector array and the first direction light are arranged at a second included angle beta, and the second included angle beta is equal to the sum of the first included angle alpha and the half field angle gamma.

Optionally, the orthogonal mirror array includes two first mirror groups and second mirror groups that are orthogonal in arrangement direction, the first mirror groups include a plurality of first mirrors that are stacked at intervals, and the second mirror groups include a plurality of second mirrors that are disposed between two adjacent first mirrors at intervals.

Optionally, when the plurality of second reflectors are arranged at intervals, a space is formed between the outermost second reflector and the end of the first reflector along the arrangement direction.

Optionally, the reflecting surface of the first reflecting mirror group is perpendicular to the reflecting surface of the second reflecting mirror group.

Optionally, the light emitting spot area of the optical machine is S1, the spot area reaching the grating through the array reflector group is S2, and when the positions of the grating and the light emitting surface of the optical machine are symmetrical, s1=s2.

Optionally, the grating area of the grating is S3, and S2 is less than or equal to S3.

According to the AR device provided by the embodiment of the application, the light is emitted from the optical machine, reflected to the grating after entering the orthogonal reflector array, and coupled into the optical waveguide by the grating for propagation. The orthogonal reflector array is adopted, so that the emergent light spot area of light rays passing through the orthogonal reflector array can be reduced, the light spot area when reaching the entrance pupil is smaller than or equal to the area of the entrance pupil, and the coupling efficiency is maximum=1; the light energy loss from the light emitted by the optical engine to the entrance pupil is effectively reduced, so that the heating of the equipment is reduced, the display brightness of an image is improved, and the performance of the AR device is enhanced.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments of the present application will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present application and should not be considered as limiting the scope, and other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic diagram of a prior art structure;

fig. 2 is a schematic diagram of the AR device structure provided in the present embodiment;

fig. 3 is a schematic view of an optical path of an AR device according to this embodiment;

FIG. 4 is a diagram showing the relationship between the orthogonal mirror array and the optical machine of the AR device according to the present embodiment;

FIG. 5 is a schematic diagram of an orthogonal mirror array of an AR device according to the present embodiment;

FIG. 6 is a schematic diagram of an AR device orthogonal mirror array optical path provided in this embodiment;

FIG. 7 is a diagram of one of the converging spots of an orthogonal mirror array of an AR device according to the present embodiment;

fig. 8 is a second view of the converging spots of an orthogonal mirror array of an AR device according to this embodiment.

Icon: 10-ray machine; a 20-orthogonal mirror array; 30-grating; 40-optical waveguide; 100-a first mirror group; 100 a-a first mirror; 101-a second mirror group; 101 a-a second mirror; f1-first direction light; f2-second direction light; an alpha-first included angle; beta-second included angle; gamma-half field angle; θ—third included angle.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application.

In the description of the present application, it should be noted that, the azimuth or positional relationship indicated by the terms "inner", "outer", etc. are based on the azimuth or positional relationship shown in the drawings, or the azimuth or positional relationship that is commonly put when the product of the application is used, are merely for convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element to be referred to must have a specific azimuth, be configured and operated in a specific azimuth, and therefore should not be construed as limiting the present application. Furthermore, the terms "first," "second," and the like, are used merely to distinguish between descriptions and should not be construed as indicating or implying relative importance.

It should also be noted that the terms "disposed," "coupled," and "connected" are to be construed broadly, and may be, for example, fixedly coupled, detachably coupled, or integrally coupled, unless otherwise specifically defined and limited; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the terms in this application will be understood by those of ordinary skill in the art in a specific context.

The longitudinal volume of the optical machine is relatively large, the optical machine needs to be placed transversely, and an optical path turning element needs to be added after the optical machine is placed transversely, so that light can enter the waveguide from the entrance pupil.

In order to save space, the optical engine adopts a transverse arrangement mode, and in order to enable light to be coupled into the optical waveguide from the entrance pupil after transverse arrangement, a reflecting mirror is usually arranged in front of the entrance pupil to reflect the light into the entrance pupil. However, turning the optical path by a mirror has the disadvantage that the spot area on reaching the entrance pupil after passing the mirror is typically too large to exceed the area of the entrance pupil.

The light spot area after reflection of the reflecting mirror is relatively large and is usually larger than the entrance pupil area, so that the coupling efficiency is reduced, the brightness of an image is finally darkened, light energy is lost, and the lost light energy can be converted into heat to heat the equipment.

One possible way to solve the above problem is to design the optical engine with a large exit pupil distance, so as to reduce the spot area when the light reaches the entrance pupil, thereby improving the coupling efficiency. Depending on the invariant of the abbe,it will be appreciated that increasing the exit pupil distance l, the lens outer diameter r, also requires some magnification, and that in order to guarantee the MTF of the image, it may also be necessary to introduce a new aspheric lens, which increases the difficulty of the opto-mechanical design and the processing cost, and is therefore not a preferred solution.

In view of this, the embodiments of the present application provide an AR device, which solves the above problem of the excessive spot area caused by using a mirror as the light path turning element. The embodiment of the application provides an AR device, which is mainly applied to AR equipment, and can also be applied to other various scenes needing to use a projection optical machine. Through this application embodiment provides an AR device, can effectively reduce light energy loss to reduce the heating of equipment, improve the display brightness of image, improve user experience.

Referring to fig. 2, an AR device is provided in the embodiment of the present application, which includes an optical engine 10, an orthogonal mirror array 20 and an optical waveguide 40, wherein an optical axis of the optical engine 10 and the optical waveguide 40 are parallel or are disposed at a preset inclination angle, the orthogonal mirror array 20 and the optical axis of the optical engine 10 are disposed at a first angle α, the optical waveguide 40 is disposed on a surface of the orthogonal mirror array 20, a light beam emitted from the optical engine 10 is reflected to the optical waveguide 30 after passing through the orthogonal mirror array 20, and is coupled into the optical waveguide 40 by the optical waveguide 30.

Preferably, the optical bench 10 is placed transversely, that is, the placing direction of the optical bench 10 is parallel to the optical waveguide 40, and the optical axis of the optical bench 10 is parallel to the optical waveguide 40; alternatively, the optical axis of the optical bench 10 and the optical waveguide 40 are disposed at a predetermined inclination angle, which may be between 0 ° and 45 °. The present application describes an example in which the optical axis of the optical machine 10 and the optical waveguide 40 are arranged in parallel.

The orthogonal mirror array 20 is located on the optical path and forms a first angle α with the optical engine 10, and the optical engine 10 is horizontally and transversely placed, that is, the orthogonal mirror array 20 forms a first angle α with the horizontal direction, that is, the x-axis direction, as shown in fig. 2; the grating 30 is located on the surface of the optical waveguide 40 and faces the side of the orthogonal mirror array 20.

The sum of the first included angle α and the half field angle γ of the optical engine 10 is smaller than 90 degrees, preferably, the sum of the first included angle α and the half field angle γ of the optical engine 10 is between 45 ° and 75 °, and the spot area of the light emitted from the optical engine 10 reaching the area of the grating 30 is smaller than or equal to the area of the grating 30.

The orthogonal mirror array 20 is also called a negative refractive index material, a negative structure, or the like, for achieving convergence of light rays, improving the light efficiency of the AR glasses, and reducing the processing cost of the optical machine 10.

In the AR device provided in this embodiment, the optical machine 10 emits light, and the light enters the orthogonal mirror array 20 and then is reflected to the grating 30, and is coupled into the optical waveguide 40 by the grating 30 to propagate. The orthogonal reflector array 20 is adopted, so that the emergent light spot area of the light after passing through the orthogonal reflector array 20 can be reduced, the light spot area when reaching the entrance pupil is smaller than or equal to the area of the entrance pupil, and the coupling efficiency is maximized=1; the light energy loss from the light emitted by the optical machine 10 to the entrance pupil is effectively reduced, so that the heating of the equipment is reduced, the display brightness of an image is improved, and the performance of the AR device is enhanced.

Further, as shown in fig. 3, the optical engine 10 and the grating 30 are respectively located at two sides of the orthogonal mirror array 20, the optical engine 10 generates a first direction light F1 and a second direction light F2, and an included angle between the first direction light F1 and the second direction light F2 forms an angle of view of the light emitted by the optical engine 10. The directions of the first direction light F1 and the second direction light F2 passing through the orthogonal mirror array 20 are symmetrical to the original direction with respect to the orthogonal mirror array 20. The light in the two directions then reaches the grating 30, and the outgoing light spot does not spread as rapidly as the mirror due to the orthogonal mirror array 20, and if the distance from the orthogonal mirror array 20 to the grating 30 is equal to the distance from the orthogonal mirror array 20 to the optical engine 10, the light spot area on the lens surface of the optical engine 10 is theoretically equal to the light spot area when reaching the grating 30, and s1=s2. Therefore, as long as the area of the grating 30 region provided at this time is larger than the area of the light-emitting surface of the optical engine 10, the coupling efficiency reaches maximum=1 theoretically at this time.

Based on the symmetrical effect of the orthogonal mirror array 20 on the light, in order to make the first direction light F1 propagate upward (the grating 30 area) after passing through the orthogonal mirror array 20, the angle between the first direction light F1 and the orthogonal mirror array 20 should satisfy a certain condition.

As shown in fig. 4, the orthogonal mirror array 20 is disposed at a second angle β with respect to the first direction light F1, and the relationship between the second angle β and the first angle α, and the half angle γ (half angle) of the light emitted from the light machine 10 is: the second angle β is equal to the sum of the first angle α and the half field angle γ, i.e., β=α+γ.

The second angle beta should satisfy the condition: beta < 90 deg..

The first included angle α is obtained by the sum of the first included angle α and the half field angle γ of the optical engine 10 being smaller than 90 degrees, and the first included angle α should satisfy the following conditions: alpha is less than 90-gamma.

Therefore, when the orthogonal mirror array 20 is disposed, the above condition needs to be satisfied to enable all light rays to propagate to the grating 30 area, so as to avoid unnecessary light energy loss.

Further, as shown in fig. 2, the positional relationship of the orthogonal mirror array 20 is macroscopically expressed as that the vector relationship among the optical machine 10, the orthogonal mirror array 20, and the grating 30 satisfies: (r1+r2) ×n=0, where r1 is a wave vector of light emitted from the optical machine 10, r2 is a wave vector of light incident on the grating 30, n is a normal vector of the orthogonal mirror array 20, a component of the normal vector n on the x-axis is sin α, a component on the y-axis is sin θ, and θ is a third angle between the orthogonal mirror array 20 and the y-axis direction, as shown in fig. 5.

Obviously, the angle of incidence of the light incident on the grating 30 (entrance pupil light) can be controlled by controlling the x-axis component and the y-axis component of the vector n, ultimately changing the position of the visual image.

Illustratively, the first included angle α is 20 ° or less and 70 °, preferably 35 ° or less and 55 °, to control the horizontal deflection angle of the visual image;

-30 ° or less of the third angle θ -30 °, preferably, -15 ° or less of the third angle θ -15 °, to control the vertical deflection angle of the visual image.

For the orthogonal mirror array 20, the orthogonal mirror array 20 includes two first mirror groups 100 and second mirror groups 101 orthogonal to each other in the arrangement direction, the first mirror groups 100 including a plurality of first mirrors 100a stacked at intervals, and the second mirror groups 101 including a plurality of second mirrors 101a disposed between adjacent two of the first mirrors 100a at intervals.

As shown in fig. 5, a schematic diagram of the orthogonal mirror array 20 is shown, where the orthogonal mirror array 20 is formed by arranging two sets of mirrors. The first mirror groups 100 are arranged along the Z-axis direction, and the reflecting surfaces of the first mirror groups 100 are perpendicular to the Z-axis. The second mirror group 101 is arranged along the y-axis, and the reflecting surface of the second mirror group 101 is perpendicular to the y-axis.

Accordingly, the reflecting surfaces of the first mirror group 100 and the second mirror group 101 are also perpendicular to each other. The schematic lines used to represent the orthogonal mirror array 20 in fig. 2, 3 and 4 are represented as the y-axis in fig. 5.

When the plurality of second mirrors 101a are arranged at intervals, a space t is formed between the outermost second mirror 101a and the end of the first mirror 100a in the arrangement direction.

Referring to fig. 5, five first mirrors 100a are arranged along the Z-axis, for example, the first mirror 100a at the bottom layer is provided with four second mirrors 101a at intervals along the y-axis, and the second mirrors 101a at the outermost side are not disposed at the level of the ends of the first mirrors 100a, but have a distance t from the ends of the first mirrors 100a, so that light can pass through the region of the distance t between the first mirrors 100a, and light is prevented from being blocked by the second mirrors 101a in the region.

The basic principle of the orthogonal mirror array 20 is to use two groups of mirror groups with mutually orthogonal reflecting surfaces to realize symmetrical processing of light, the schematic diagram of the light path is shown in fig. 6, the light emitted by the light source P is incident to the second mirror group 101, the incident light at different angles has different processes, the PO light can be directly emitted as P' O after being reflected by the first mirror group 100, and PA ₁ The light beam passing through the first mirror group 100 is reflected to the second mirror group 101 due to the angle, and then reflected to P' A ₂ And (5) emergent. But ultimately, whether it is PA ₁ Or PO, all of which exit rays are symmetrical with respect to the ZOX plane itself.

Compared with the prior art, the orthogonal mirror array 20 can converge the light spot area of the orthogonal mirror array 20, as shown in fig. 7, the light spot area of the light emitted by the optical machine 10 is S1, the light spot area is always increased before reaching the orthogonal mirror array 20, and after passing through the orthogonal mirror array 20, the light path deflects towards the direction of the grating 30, and is symmetrical to the original light path about the orthogonal mirror array 20. The light spot area gradually contracts and then spreads again in a certain optical path, the light spot area when reaching the entrance pupil area is set as S2, and if the light spot area is the optical path from the position S1 to the orthogonal mirror array 20 and is equal to the optical path from the orthogonal mirror array 20 to the position S2, s1=s2. The foregoing is an application of the orthogonal mirror array 20 in this application, and in a specific application, the distances between the optical machine 10, the orthogonal mirror array 20, and the grating 30 regions may be reasonably arranged according to the area of the grating 30 region.

In one embodiment, an optical machine 10 having an angle of view of 80 ° is selected, as shown in fig. 7, whereby the angle of half angle of view γ takes on a value of 40 °, since the second angle β needs to be smaller than 90 °. Therefore, the value of the first included angle α is smaller than 50 °, and the first included angle α is set to be 30 ° in this embodiment.

As shown in fig. 8, the present application provides a high-efficiency grating coupling mode, and the light spot area at the lens of the optical machine 10 is S1, the light spot area when reaching the grating 30 area is S2, and the grating 30 area is S3. The light with the spot area S1 is emitted from the optical machine 10, propagates a certain distance, reaches the orthogonal mirror array 20, is emitted symmetrically to the direction of the grating 30 at the orthogonal mirror array 20, propagates a certain distance, and reaches the grating 30 region.

As can be seen from the calculation formula of the coupling efficiency, the spot area S2 reaching the grating 30 region may be equal to or smaller than the area S3 of the grating 30 region. Thus, the location of placement of the regions of grating 30 may vary somewhat, as noted in FIG. 8. Considering practical scene applications, the more compact it is generally, the better, so the grating 30 region is preferentially arranged in the region of the lower spot area S3.

The application provides an AR device, the light of ray apparatus 10 outgoing is after quadrature mirror array 20, and the facula area obtains the convergence, reaches the regional facula area of grating 30 and equals the regional area of grating 30, and coupling efficiency reaches 100% in theory, compares in current speculum turn light path, is showing and is improving coupling efficiency, effectively reduces the light energy loss of ray apparatus 10 light-emitting to entrance pupil department to reduce the heating of equipment, improve the display brightness of image, strengthened the performance of AR equipment.

The foregoing is merely exemplary embodiments of the present application and is not intended to limit the scope of the present application, and various modifications and variations may be suggested to one skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. An AR device, comprising: the optical axis of the optical machine is parallel to the optical waveguide or is arranged at a preset inclination angle, the orthogonal mirror array and the optical axis of the optical machine are arranged at a first included angle alpha, a grating is arranged on one surface of the optical waveguide, which faces to the orthogonal mirror array, of the optical waveguide, and light rays emitted by the optical machine are reflected to the grating after passing through the orthogonal mirror array and are coupled into the optical waveguide by the grating; the orthogonal reflector array is used for realizing symmetrical processing of the light rays; the orthogonal reflector array comprises a first reflector group and a second reflector group, wherein the two first reflector groups and the second reflector group are orthogonal in arrangement direction, the first reflector group comprises a plurality of first reflectors which are stacked at intervals, and the second reflector group comprises a plurality of second reflectors which are arranged between two adjacent first reflectors at intervals;

the vector relationship among the optomachine, the orthogonal mirror array and the grating satisfies: (r1+r2) x n=0, where r1 is a wave vector of light emitted by the optical machine, r2 is a wave vector of incident light of the grating, n is a normal vector of the orthogonal mirror array, a component of the normal vector n on the x-axis is sin α, a component on the y-axis is sin θ, and θ is a third included angle between the orthogonal mirror array and the y-axis;

the first included angle alpha is more than or equal to 20 degrees and less than or equal to 70 degrees, and the third included angle theta is more than or equal to-30 degrees and less than or equal to 30 degrees;

the light machine emits first-direction light and second-direction light, and an included angle between the first-direction light and the second-direction light forms an angle of view of light emitted by the light machine; the sum of the first included angle alpha and the half field angle gamma of the optical machine is smaller than 90 degrees; the orthogonal reflector array and the first direction light are arranged at a second included angle beta, and the second included angle beta is equal to the sum of the first included angle alpha and the half field angle gamma.

2. The AR device of claim 1, wherein the optomachine and the grating are located on either side of the orthogonal mirror array.

3. The AR device according to claim 1, wherein when the plurality of second mirrors are arranged at intervals, a space is formed between the outermost second mirror and the end of the first mirror in the arrangement direction.

4. The AR apparatus according to claim 1, wherein the reflective surface of the first mirror group and the reflective surface of the second mirror group are perpendicular.

5. The AR device according to claim 1, wherein the light-emitting spot area of the optical engine is S1, the spot area reaching the grating through the array mirror group is S2, and s1=s2 when the positions of the grating and the light-emitting surface of the optical engine are symmetrical.

6. The AR device of claim 5, wherein the grating has a grating area S3, S2 is less than or equal to S3.