WO2022142565A1

WO2022142565A1 - Optical assembly and ar device

Info

Publication number: WO2022142565A1
Application number: PCT/CN2021/122520
Authority: WO
Inventors: 朱瑞; 惠晓辉; 李德华
Original assignee: 歌尔股份有限公司
Priority date: 2020-12-28
Filing date: 2021-10-07
Publication date: 2022-07-07
Also published as: CN112596245A

Abstract

The embodiments of the present application provide an optical assembly and an AR device. The optical assembly is applied to the AR device, and the optical assembly comprises: a display assembly; and an optical element based on a birefringence effect, wherein the optical element and the display assembly are arranged at intervals; at least part of light emitted by the display assembly is perpendicularly incident to an incident surface of the optical element, and the optical element converts at least part of the light from the display assembly into o light and e light and emits same; and the optical element and the display assembly can move relative to each other so as to expand an emission range of the e light. According to the technical solution of the present application, an optical element based on a birefringence effect is provided on an optical path emitted by a display assembly, the optical element converts at least part of light emitted by the display assembly into o light and e light, and the optical element and the display assembly move relative to each other so as to expand an emission range of the e light, thereby increasing the range of eyebox of the whole optical assembly, and thus improving the user experience as a whole.

Description

An optical component and AR device

This application claims the priority of the Chinese patent application with the application number 202011584538.3 and the invention titled "An Optical Component and AR Device" filed with the China Patent Office on December 28, 2020, the entire contents of which are incorporated into this application by reference .

technical field

The present application relates to the technical field of smart devices, and in particular, to an optical component and an AR device.

Background technique

AR equipment is an intelligent connection device between the virtual world and the real world. Through AR glasses, you can see the real world and virtual content, and you can interact with information such as vision and hearing.

Most of the current smart AR devices, especially head-mounted augmented reality near-eye display devices, use diffractive optical waveguides to expand the scope of the eye-moving frame. Usually, the scope of the eye-movement frame is strongly related to the size of the coupling-out area, and expanding the eye-movement orbit can enhance the user experience. However, it is more difficult to enlarge the eye socket.

SUMMARY OF THE INVENTION

The main purpose of the present application is to provide an optical component and an AR device, which aims to solve the difficult problem of expanding the eye orbit of the current smart AR device, so as to improve the user experience as a whole.

In order to achieve the above object, the present application proposes an optical assembly, which is applied to an AR device. The optical assembly includes: a display assembly; an optical element based on a birefringence effect, the optical element and the display assembly are arranged at intervals; the display At least part of the light emitted from the component is vertically incident on the incident surface of the optical element, and the optical element converts at least part of the light from the display component into o-light and e-light and emits; wherein, the optical element and the The display assembly can move relatively to expand the emission range of the e-light.

Optionally, at least one o-light separation image is formed after the o-light is transmitted out of the optical element; at least one e-light separation image is formed after the e-light is transmitted out of the optical element.

Optionally, in a direction parallel to the incident surface, the display assembly moves relative to the optical element in a predetermined trajectory, and/or the optical element moves relative to the display assembly in a predetermined trajectory .

Optionally, the preset trajectory is a straight trajectory and/or a circular trajectory.

Optionally, the optical element rotates relative to the display assembly with its central axis.

Optionally, the optical element includes: a uniaxial birefringent crystal, an optical element based on a stress birefringence effect, or an optical element based on an electric birefringence effect.

Optionally, the refractive index of the optical element for the o light is the first refractive index, the refractive index for the e light is the second refractive index, and the difference between the second refractive index and the first refraction index is greater than 0.15.

Optionally, the thickness between the incident surface and the exit surface of the optical element is greater than 5 mm.

In addition, the present application further provides an AR device, the AR device includes the optical assembly described in any one of the above, and a casing, wherein the display assembly and the optical element are arranged on the casing at intervals.

Optionally, the housing includes: a mirror frame, the left and right sides of the mirror frame are provided with mirror frames, and each mirror frame is provided with a lens; two mirror legs, the two mirror legs are respectively arranged in the At the left and right ends of the mirror frame, at least one of the temples is provided with the display assembly and/or the optical element, and the light of the display assembly passes through the optical element to form o-light and e-light and exit.

Optionally, the AR device includes a housing for wearing on the user's head and; wherein, at least one group of the optical elements is arranged in the housing, and the light of the display assembly passes through the optical elements to form an o Light and e-light exit together.

The technical solution of the present application is to provide an optical element based on the birefringence effect on the light path emitted by the display assembly, the optical element converts at least part of the light emitted by the display assembly into o light and e light, and the optical element moves relative to the display assembly to enlarge e The outgoing range of light increases the orbital range of the entire optical component, thereby improving the user experience as a whole.

Description of drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the accompanying drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only It is a part of the drawings of the present application. For those of ordinary skill in the art, other drawings can also be obtained from the provided drawings without any creative effort.

FIG. 1 is a schematic structural diagram of an embodiment of an optical component of the present application;

FIG. 2 is a schematic structural diagram of still another embodiment of the optical assembly of the present application;

FIG. 3 is a schematic structural diagram of another embodiment of the optical assembly of the present application;

FIG. 4 is a schematic structural diagram of an embodiment of an AR device of the present application.

Description of reference numbers:

标号label	名称 name	标号label		名称name
100100	光学组件 Optical components	1010	显示组件 display components
2020	光学元件 Optical element	200200	AR设备 AR device
210210	镜架 frame	220220	镜腿 temples
230230	镜片lens

The realization, functional characteristics and advantages of the purpose of the present application will be further described with reference to the accompanying drawings in conjunction with the embodiments.

Detailed ways

The technical solutions in the embodiments of the present application will be described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

The optical components in the embodiments of the present application are mainly applied to AR devices, such as AR glasses or AR helmets. In current AR devices, especially head-mounted augmented reality near-eye display devices, various display indicators are closely related to the characteristics of the human visual system and directly related to the user experience, such as angular resolution, color difference, brightness, and field of view (FOV). ) and Eyebox range, etc.

Among them, eye movement is a very important factor in head-mounted display devices, especially in AR devices, which directly affects the range of virtual images that users can see, that is, determines the flexibility of users to wear AR glasses every day. For example, if the Eyebox is too small, if you move your eyeballs a little, the virtual content you see will be incomplete, which greatly reduces the user experience.

As shown in FIG. 1 to FIG. 4, the present application proposes an optical assembly 100, which is applied to an AR device. The optical assembly 100 includes: a display assembly 10 for displaying a virtual image; an optical element 20 based on a birefringence effect, The optical element 20 is spaced apart from the display assembly 10 ; at least part of the light emitted from the display assembly 10 is vertically incident on the incident surface of the optical element 20 , and the optical element 20 will at least partially come from the display assembly 10 The light is converted into o light and e light and emitted; wherein, the optical element 20 and the display assembly 10 can move relative to each other, so as to expand the emission range of the e light.

In the embodiment of the present application, in order to expand the scope of the eye-moving frame, the optical element 20 based on the birefringence effect is arranged in the light beam exit direction of the display assembly 10, and the virtual image that needs to be presented to the human eye is transmitted to the optical element 20 based on the birefringence effect. , using the optical element 20 based on the birefringence effect to refract at least part of the light emitted by the display assembly 10 into o light and e light, so that the separated image of the generated e light moves rapidly in the enlarged eye frame area, based on the persistence of vision Phenomenon uses e-light to realize the expansion of the eye frame.

It should be noted that, the optical element based on the birefringence effect in the embodiments of the present application may specifically be a uniaxial birefringent crystal, an optical element based on the stress birefringence effect, or an optical element based on the electric birefringence effect, or the like.

It can be understood that birefringence is a phenomenon in which a light beam incident on an anisotropic crystal is decomposed into two beams and refracted in different directions. When light propagates in an inhomogeneous body, the refractive index of material to o light and e light is different, which causes its propagation speed and refractive index to change with different vibration directions. This phenomenon is called birefringence. When the crystal is rotated, the imaging position of the e-light will rotate around the o-light.

In some embodiments, at least one o-light separation image is formed after the o-light is transmitted out of the optical element; at least one e-light separation image is formed after the e-light is transmitted out of the optical element. For example, after the o-light is transmitted out of the optical element, an o-light separation image can be formed, and the o-light separation image can be located at the center of the outgoing light. After the e-light is transmitted out of the optical element, multiple e-light separation images can be formed, and these e-light separation images can be uniformly or unevenly distributed around the o-light separation image; The light separation image is the same image.

It can be understood that, in order to ensure that the light emitted by the display assembly 10 can form a complete virtual image, it is necessary to ensure that at least part of the light of the display assembly 10 is vertically incident on the incident surface of the optical element 20 based on the birefringence effect. For example, light from a predetermined central area of the display component 10 is incident on the incident surface of the optical element 20 perpendicularly, and light from a predetermined edge area of the display component 10 is incident on the incident surface of the optical component 20 at a non-right angle.

In some embodiments, in a direction parallel to the incident surface, the display assembly moves relative to the optical element in a predetermined trajectory, and/or the optical element moves relative to the display assembly in a predetermined trajectory sports. The preset trajectory can be a straight trajectory and/or a circular trajectory.

Specifically, the relative movement of the display assembly 10 and the optical element 20 may be based on the movement of the display assembly 10 relative to the optical element 20 on a plane parallel to the incident surface, or, based on the optical element 20 relative to the display assembly 10 in a plane parallel to the incident surface The surface moves on the plane, and the motion can be linear reciprocating motion, circular motion, etc. Through the above structure arrangement, the output range of the e-light can be expanded without changing the characteristics of the beam emitted by the display assembly 10, so as to achieve the purpose of expanding the scope of the eye-moving frame and avoid incomplete virtual content viewed by the user.

In some specific embodiments, the display assembly 10 may be an optomechanical system, and the light output image of the optomechanical system (microprojection or flat panel display) is a rectangle or a circle, and the axial cross section of the optical element 20 based on the birefringence effect may be If the shape is similar to it, the movement of the display assembly 10 relative to the optical element 20 on a plane parallel to the incident surface is as follows: first, the optomechanical system reciprocates in its radial direction, so that the light output range of the optomechanical system is enlarged, The tiling range of the e-light refracted by the optical element 20 based on the birefringence effect is enlarged; secondly, the group axis of the light emitted by the optomechanical system is used as the central axis, so that the optomechanical system is a certain distance relative to the central axis, and is placed around the central axis. The central axis makes a circular motion, so that the e-light refracted by the optical element 20 based on the birefringence effect expands the tiling range.

The movement of the optical element 20 based on the birefringence effect relative to the display assembly 10 on a plane parallel to the incident surface may be: first, the optical element 20 based on the birefringence effect reciprocates in its radial direction, so that the birefringence based optical element 20 reciprocates The tiling range of the e-light refracted by the optical element 20 of the effect is enlarged; secondly, the optical element 20 based on the birefringence effect is a certain distance from the central axis with the central axis of the surface on which the light is emitted by the optomechanical system, and is arranged around the central axis. A circular motion is performed to increase the tiling range of the e-light refracted by the optical element 20 based on the birefringence effect.

Specifically, the preset trajectory is a straight trajectory, and the display assembly 10 reciprocates and translates relative to the optical element 20 based on the birefringence effect along the straight trajectory. In this embodiment, the preset trajectory can be a straight trajectory. As shown in FIG. 1 , on a surface parallel to the incident surface, the display assembly 10 is moved back and forth in a straight line, so that the light-emitting range of the optical-mechanical system is enlarged, and the birefringence-based The e-ray tiling range refracted by the optical element 20 of the effect is increased.

It can be understood that, if each set of optical assemblies 100 corresponds to a single human eye, when two sets of optical assemblies 100 are used, the two sets of optical assemblies 100 are arranged as lateral mirror images along the binocular direction relative to the center point of the human eye. The optical axes of the display assembly 10 or the optical element 20 based on the birefringence effect are in the same direction, that is, the optical axis is perpendicular to the incident surface of the optical element 20 based on the birefringence effect, and the reciprocating and translational motions must be perpendicular to the optical axis, depending on the specific optics of the system. The design determines the specific movement direction in this plane, and the movement direction makes the reflected light incident to the human eye synchronously realize one-dimensional or two-dimensional tiling.

It can be understood that the moving speed and moving distance of the display assembly 10 are related to the thickness and principal refractive index difference of the optical element 20 based on the birefringence effect, but the moving period needs to be less than the visual persistence time to ensure that the human eye will not notice the image. The position or strength changes, and the size of the imaged Eyebox is not less than 20×20mm.

Specifically, the preset trajectory is a circular trajectory, and the display assembly 10 moves circumferentially relative to the optical element 20 along the circular trajectory, so as to expand the emission range of the e-light. In this embodiment, the preset trajectory may be a circular trajectory. As shown in FIG. 2 , the display assembly 10 is set as an optomechanical system, and the axis of the light-emitting group of the optomechanical system is used as the central axis, so that the The light-emitting component is at a certain distance from the central axis, and performs a circular motion around the central axis, so that the e-light refracted by the optical element 20 has a larger tiling range.

Specifically, the preset trajectory may be a circular trajectory, and the optical element 20 based on the birefringence effect moves circumferentially relative to the display assembly 10 along the circular trajectory to expand the emission range of the e-light. In this embodiment, the display assembly 10 is set as an optomechanical system, and the axis of the light-emitting surface of the optomechanical system is used as the central axis, so that the optical element 20 is a certain distance from the central axis, and makes a circular motion around the central axis, The tiling range of the e-light refracted by the optical element 20 is enlarged.

As shown in FIG. 3 , specifically, the optical element 20 can rotate relative to the display assembly 10 with its own central axis. In this embodiment, since the inside of the optical element 20 has a crystal plane with a different angle from the incident plane, when the optical element 20 is rotated, the orientation of the optical axis of the crystal in the optical element 20 can be changed, so that the optical element 20 can be refracted from different orientations e-light, to achieve the purpose of expanding the emission range of the e-light.

Specifically, the refractive index of the optical element 20 for the o light is the first refractive index, the refractive index for the e light is the second refractive index, and the difference between the second refractive index and the first refraction index is greater than 0.15. In this embodiment, the display assembly 10 moves relative to the optical element 20 on a plane parallel to the incident surface as an example, after the light beam transmitted from the display assembly 10 enters the optical element 20, the two beams of birefringence are separated by a certain distance in order to ensure , based on the difference between the first refractive index of the optical element 20 for o light and the second refractive index for e light, Δn>0.15 is preferable. The optical axis of the birefringent crystal is oblique to the crystal surface, the incident light is perpendicular to the crystal, and the incident surface and the exit surface of the crystal are parallel.

Specifically, the thickness between the incident surface and the outgoing surface of the optical element 20 is greater than 5 mm. In this embodiment, it is taken as an example that the display assembly 10 moves relative to the optical element 20 on a plane parallel to the incident surface. Since the range of the eye-moving frame is related to the refractive index difference and thickness of the optical element 20, After static placement, the optical element 20 of the display assembly 10 is arranged in the temple 220 of the AR glasses, and is integrated into the structure of the temple 220. The thickness of the optical element 20 is not less than 5mm, and the birefringent image (light beam) can pass through the AR glasses. After being reflected by the lens 230, it is incident to the human eye.

Specifically, the optical element 20 is formed of a uniaxial birefringent crystal. In this embodiment, the material of the optical element 20 based on the birefringence effect may be yttrium vanadate (YVO4), titanium dioxide (TiO2), and calcite (CaCO3).

In the above structure, the effect of enlarging the eye-moving frame is achieved through geometric optics, and the problem of chromatic aberration may not be introduced.

In addition, the optical element 20 may be an optical element based on the stress birefringence effect, which generates anisotropy based on the action of mechanical stress. Under the action of pressure or tension, the refractive index characteristics of a transparent isotropic medium will change, thereby showing out optical anisotropy.

Furthermore, the optical element 20 may also be an optical element based on the electro-birefringence effect. For example, a specific liquid (such as nitrobenzene) is filled in a transparent box equipped with a parallel plate capacitor, and the voltage between the electrodes is connected to generate an electric field between the two polar plates, and the liquid becomes an anisotropic medium and produces double refraction. Alternatively, when KDP (potassium dihydrogen phosphate) applies an electric field in a certain direction, birefringence occurs in the crystal for incident light in a certain direction.

As shown in FIG. 4 , an embodiment of the present application further provides an AR device 200 , including the optical assembly 100 described above, and a casing (not marked in the figure), the display assembly 10 and the birefringence effect-based AR device 200 . The optical elements 20 are arranged on the housing at intervals. The specific structure of the optical assembly 100 refers to the above-mentioned embodiments. Since the AR device 200 adopts at least part of the technical solutions of the above-mentioned embodiments, it has at least the beneficial effects brought by the technical solutions of the above-mentioned embodiments, which will not be repeated here. .

In some embodiments, the housing includes: a mirror frame 210 , and mirror frames are opened on the left and right sides of the mirror frame 210 , and each mirror frame is provided with a lens 230 ; two mirror legs 220 , two mirror legs 220 They are respectively disposed at the left and right ends of the mirror frame, and at least one of the temples 220 is provided with the display assembly 10 and/or the optical element 20 based on the birefringence effect, and the light of the display assembly 10 passes through the optical The element 20 forms and emits o-light and e-light. The o-light and the e-light emitted from the optical element 20 can be directly incident on the user's eyes, or firstly irradiated to the lens 230 and then reflected to the human eye through the lens 230 .

In some embodiments, the optical assembly 100 can be applied to glasses to form AR glasses, wherein the display assembly 10 and the optical element 20 are integrated on the temple 220, and the light of the display assembly 10 is formed through the optical element 20 based on the birefringence effect. The o light and the e light are irradiated on the lens 230 and reflected to the human eye through the lens 230 .

Specifically, the lens 230 is made of optical resin. In this embodiment, the material of the lens 230 may be PMMA, or may be a high-refractive-index and low-dispersion high-transparency glass material from Corning and Schott. In addition, the lens 230 can also be made of optical waveguide material.

In this embodiment, the optical assembly 100 can be applied to a head-mounted casing to form the AR device 200. For example, the casing is a helmet, and the helmet is provided with a window. The position of the window is relative to the position of the human eye. In the housing, the light of the display assembly 10 passes through the optical element 20 based on the birefringence effect to form o-light and e-light, and enters the human eye through the viewing window.

The above descriptions are only preferred embodiments of the present application, and are not intended to limit the scope of the patent of the present application. Under the conception of the present application, the equivalent structural transformations made by the contents of the description and drawings of the present application, or directly/indirectly applied in the Other related technical fields are included within the scope of patent protection of this application.

Claims

An optical assembly, characterized in that, applied to an AR device, the optical assembly comprising:

display component;

An optical element based on a birefringence effect, the optical element and the display assembly are spaced apart;

At least part of the light emitted from the display assembly is vertically incident on the incident surface of the optical element, and the optical element converts at least part of the light from the display assembly into o-light and e-light and emits; wherein, the optical element It is movable relative to the display assembly to expand the emission range of the e-light.
The optical assembly of claim 1, wherein

After the o-light is transmitted out of the optical element, at least one o-light separation image is formed;

After the e-light is transmitted out of the optical element, at least one e-light separation image is formed.
The optical assembly according to claim 1, characterized in that, in a direction parallel to the incident surface, the display assembly moves relative to the optical element in a predetermined trajectory, and/or the optical element moves with The preset trajectory moves relative to the display assembly.
The optical assembly according to claim 3, wherein the preset trajectory is a straight trajectory and/or a circular trajectory.
The optical assembly of claim 1, wherein the optical element rotates relative to the display assembly with its central axis.
The optical assembly of claim 1, wherein the optical element comprises:

Uniaxial birefringent crystals, optical elements based on the stress birefringence effect, or optical elements based on the electric birefringence effect.
The optical component according to claim 1, wherein the refractive index of the optical element for o light is a first refractive index, and the refractive index for e light is a second refractive index, and the second refractive index is the same as the first refractive index. The difference of a broken line rate is greater than 0.15.
The optical assembly according to claim 1, wherein the thickness between the incident surface and the exit surface of the optical element is greater than 5 mm.
An AR device is characterized by comprising the optical assembly according to any one of claims 1 to 8, and a casing, wherein the display assembly and the optical element are arranged on the casing at intervals.
The AR device of claim 9, wherein the housing comprises:

a mirror frame, the left and right sides of the mirror frame are provided with mirror frames, and each of the mirror frames is provided with a lens;

Two temples, the two temples are respectively arranged at the left and right ends of the frame, at least one of the temples is provided with the display assembly and/or the optical element, and the light of the display assembly passes through all the mirrors. The optical element forms and emits o light and e light.
The AR device of claim 9, wherein the AR device comprises a housing for wearing on the user's head;

Wherein, at least one group of the optical elements is arranged in the housing, and the light emitted from the display assembly passes through the optical elements to form o-light and e-light and exit.