WO2024087733A1 - Light guide device and wearable device - Google Patents

Abstract

A light guide device and a wearable device. The light guide device comprises a waveguide substrate (100), and an in-coupling region (110) and an out-coupling region (120), which are arranged on the waveguide substrate (100). The out-coupling region (120) is provided with at least two basic out-coupling units, each of which comprises a first out-coupling sub-grating (121) and a second out-coupling sub-grating (122), wherein the grating vector of the first out-coupling sub-grating (121) is a first vector K1, the grating vector of the second out-coupling sub-grating (122) is a second vector K2, and a predetermined included angle is formed between the first vector K1 and the second vector K2. Light incident on the waveguide substrate (100) via the in-coupling region (110) is fully reflected in the waveguide substrate (100) and propagated to the basic out-coupling units, and the basic out-coupling units perform pupil dilation on the light in two different dimensional directions, such that the light can be spread over the entire out-coupling region (120). The light guide device realizes, in the out-coupling region (120) and by combining one-dimensional gratings, the functions of two-dimensional pupil dilation and light out-coupling.

Description

Light guide device and wearable device

This application claims priority to the Chinese patent application filed with the China Patent Office on October 25, 2022, with application number 202211311980.8 and invention name “A light-guiding device and wearable device”, the entire contents of which are incorporated by reference in this application.

Technical Field

The present application belongs to the field of augmented reality technology. Specifically, the present application relates to a light guide device and a wearable device.

Background technique

Augmented Reality (AR) is a technology that cleverly integrates virtual information with the real world. Currently, diffractive optical waveguides are commonly used to implement augmented reality solutions.

In the prior art, diffraction optical waveguide devices usually adopt a design of one-dimensional grating coupling in and two-dimensional grating pupil expansion coupling out. The light propagation path is that the light coupled into the waveguide expands to both sides when encountering the two-dimensional grating. However, due to the symmetry of light diffraction and the fact that the pupil expansion direction of the two-dimensional grating is fixed and the angles in two directions cannot be adjusted, there is always at least one corner on the two-dimensional grating that will have a dark angle of the field of view, which seriously affects the uniformity and integrity of the image displayed by the optical waveguide, and thus affects the user experience. Moreover, the design of the two-dimensional grating is relatively complex and will increase the production cost. In response to this, a scheme of forming a two-dimensional pupil expansion with two one-dimensional gratings is proposed, but it is found that the light cannot be effectively expanded in one direction during the two-dimensional pupil expansion. For example, in the existing scheme, the coupling-in area is usually located at the central axis position of the coupling-out area, which will result in the light being unable to be effectively expanded in the longitudinal direction, thereby affecting the improvement of the longitudinal eyebox.

Summary of the invention

The purpose of the embodiments of the present application is to provide a new technical solution for light-guiding devices and wearable devices.

According to a first aspect of an embodiment of the present application, a light guide device is provided. The light guide device includes a waveguide substrate and an incoupling region and an outcoupling region arranged on the waveguide substrate;

The coupling-out region is provided with at least two basic coupling-out units of set shapes. The output unit includes a first sub-output grating and a second sub-output grating;

The grating vector of the first sub-outcoupling grating is a first vector K1, and the grating vector of the second sub-outcoupling grating is a second vector K2, and a predetermined angle is formed between the first vector K1 and the second vector K2; the light emitted into the waveguide substrate through the coupling-in region is totally reflected in the waveguide substrate and propagates to the basic outcoupling unit, and the basic outcoupling unit expands the pupil of the light in two different dimensional directions so that the light can cover the entire outcoupling region.

Optionally, the first vector K1 and the second vector K2 form an angle of 60 degrees.

Optionally, in the basic outcoupling unit: the first sub-outcoupling grating and the second sub-outcoupling grating are located on the same surface of the waveguide substrate and are arranged adjacent to each other.

Optionally, in the basic outcoupling unit: the first sub-outcoupling grating and the second sub-outcoupling grating are respectively arranged on two surfaces of the waveguide substrate, and are at least partially overlapped in the projection direction.

Optionally, in the basic outcoupling unit: a first vector K1 of the first sub-outcoupling grating and a second vector K2 of the second sub-outcoupling grating form a mirror-symmetric structure.

Optionally, the coupling region is provided with a coupling grating, the coupling grating comprises a one-dimensional grating, and the grating vector of the coupling grating is a third vector K3;

The angles between the first vector K1 , the second vector K2 , and the third vector K3 are 60 degrees, and the first vector K1 , the second vector K2 , and the third vector K3 can form a closed equilateral triangle.

Optionally, the periods of the coupling-in grating, the first sub-coupling grating and the second sub-coupling grating are the same.

Optionally, the period range of the coupling-in grating, the first sub-coupling grating and the second sub-coupling grating is 200nm-600nm.

Optionally, the coupling-in grating, the first sub-coupling grating and the second sub-coupling grating are all one-dimensional gratings, and the one-dimensional grating includes any one of a relief grating, a holographic grating and a photonic crystal grating.

Optionally, the basic outcoupling unit is provided in plurality, and the plurality of the basic outcoupling units are arranged in a matrix on at least one surface of the waveguide substrate.

Optionally, the light is injected into the waveguide substrate through the coupling-in region to generate a light beam toward the waveguide substrate. The first diffracted light propagated by the basic outcoupling unit;

When the first diffracted light first encounters the first out-coupling sub-grating, a second diffracted light is generated to propagate to one side, and part of the second diffracted light generates out-coupling light and emits when encountering the adjacent second out-coupling sub-grating, and another part of the second diffracted light continues to propagate and generates a third diffracted light when encountering the first out-coupling sub-grating again, and the third diffracted light has the same diffraction direction as the first diffracted light;

The light of the first diffracted light that continues to propagate is transmitted to the second sub-coupling grating to generate fourth diffracted light that propagates to one side. The fourth diffracted light generates out-coupling light when it enters the adjacent first sub-coupling grating and is emitted.

According to a second aspect of the embodiments of the present application, a wearable device is provided. The wearable device includes:

The light guide device according to the first aspect; and

An optical machine is used to inject light or an image into the light guiding device.

The beneficial effects of the embodiments of the present application are:

The embodiment of the present application provides a diffraction optical waveguide design scheme, in which at least two basic out-coupling units are formed in the out-coupling area by optimizing and combining one-dimensional gratings, and a two-dimensional pupil expansion and out-coupling function is realized in the out-coupling area. External light is coupled into the waveguide substrate through the coupling-in area and propagates to the basic out-coupling unit through total reflection. The basic out-coupling unit is a pupil expansion and out-coupling area, which can effectively expand the light in two different dimensional directions and finally cover all areas of the entire out-coupling area, thereby effectively increasing the light output area, so that the human eye can obtain a clear and complete image in the entire field of view, and can enhance the user's visual experience.

Other features and advantages of the present application will become apparent from the following detailed description of exemplary embodiments of the present application with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the application and, together with the description, serve to explain the principles of the application.

FIG1 is a schematic diagram of a structure of a light guide device according to an embodiment of the present application;

FIG2 is a schematic diagram of a basic coupling-out unit according to an embodiment of the present application;

FIG3 is a second structural diagram of a basic coupling-out unit provided in an embodiment of the present application;

FIG4 is a third structural diagram of a basic coupling-out unit provided in an embodiment of the present application;

FIG5 is a fourth structural diagram of a basic coupling-out unit provided in an embodiment of the present application;

FIG6 is a second schematic diagram of the structure of the light guide device provided in an embodiment of the present application;

FIG. 7 is a schematic diagram of the relationship between the coupling-in grating and the grating vectors of the basic coupling-out unit provided in an embodiment of the present application.

Description of reference numerals:

100, waveguide substrate; 110, coupling-in region; 111, coupling-in grating; 120, coupling-out region; 121, first sub-coupling grating; 122, second sub-coupling grating;

001, first diffracted light; 002, second diffracted light; 003, third diffracted light; 004, fourth diffracted light; 011, outcoupled light.

Detailed ways

Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. It should be noted that unless otherwise specifically stated, the relative arrangement of components and steps, numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present application.

The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the present application, its application, or uses.

Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered as part of the specification.

In all examples shown and discussed herein, any specific values should be interpreted as merely exemplary and not limiting. Therefore, other examples of the exemplary embodiments may have different values.

It should be noted that like reference numerals and letters refer to similar items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

The light guide device and the wearable device provided in the embodiments of the present application are described in detail below with reference to the accompanying drawings.

Among various forms of head-mounted display devices, AR devices are taken as an example. AR devices usually include a micro display screen and an optical module. Optical elements commonly used in the optical module of AR devices include, for example, prisms, free-form surface lenses, and optical waveguide devices. Among the above-mentioned optical elements, optical waveguide devices include geometric optical waveguides and diffraction optical waveguides. Due to the good optical properties of diffraction optical waveguides, they have been widely used in AR devices.

According to an embodiment of the present application, a light guide device is provided. The light guide device is, for example, an optical waveguide device, and the optical waveguide device is, for example, a diffraction optical waveguide. The light guide device provided in the embodiment of the present application can be applied to, for example, a wearable device.

The wearable device includes a head-mounted display device, such as AR smart glasses, AR helmets, etc. The specific form of the head-mounted display device is not limited in this application.

The present application discloses a light guide device, referring to FIGS. 1 to 6 , the light guide device comprises a waveguide substrate 100 and an incoupling region 110 and an outcoupling region 120 disposed on the waveguide substrate 100;

The outcoupling region 120 is provided with at least two basic outcoupling units of set shapes, each of the basic outcoupling units includes a first sub-outcoupling grating 121 and a second sub-outcoupling grating 122; the grating vector of the first sub-outcoupling grating 121 is a first vector K1, and the grating vector of the second sub-outcoupling grating 122 is a second vector K2, and a predetermined angle is formed between the first vector K1 and the second vector K2; the light emitted into the waveguide substrate 100 through the coupling region 110 is totally reflected in the waveguide substrate 100 and propagates to the basic outcoupling unit, and the basic outcoupling unit expands the light in two different dimensional directions so that the light can cover the entire outcoupling region 120.

The light-guiding device provided by the embodiment of the present application has a coupling-in area 110 and a coupling-out area 120 respectively arranged on the waveguide substrate 100, and the external light (image) can be coupled into the waveguide substrate 100 through the coupling-in area 110, and the coupled-in light propagates toward the coupling-out area 120 in the waveguide substrate 100 by total reflection. When the light propagates to the coupling-out area 120 and encounters each of the basic coupling-out units, the light can be dilated along two different dimensional directions at each of the basic coupling-out units, and finally the light can be spread over the entire coupling-out area 120, so that the light output area of the coupling-out area 120 on the entire light-guiding device can be increased. Since the light spreads over the entire coupling-out area 120 after the pupil is dilated, the complete picture can be clearly seen within the field of view of the human eye, which can enhance the user's visual experience.

The existing two-dimensional grating pupil expansion method cannot achieve the effect of making the light cover the entire outcoupling area. This is because although the two-dimensional grating can expand the pupil of light in two different directions, these two directions are fixed to be perpendicular to each other and cannot be adjusted. After the pupil is expanded, the light cannot propagate to certain areas of the outcoupling area. There will always be some corners with dark corners of the field of view, resulting in part of the outcoupling area being able to emit light, while other parts may not be able to emit light. The human eye will move within a certain range, and it needs to be able to see the light during the movement. It can be seen that the existing two-dimensional grating pupil expansion scheme will limit the use range of the human eye, that is, the eyebox is smaller. The existing combination of two one-dimensional gratings may result in the expansion of light in the longitudinal direction being limited, and ultimately the light cannot cover the entire outcoupling area. It can be seen that the existing schemes will limit the light output area of the outcoupling area and affect the imaging quality.

The light-guiding device provided in the embodiment of the present application has the decoupling area 120 thereon using two or more basic decoupling units, wherein each basic decoupling unit can be formed by combining two one-dimensional gratings at a set angle. Specifically, each one-dimensional grating has a single vector direction, and by adjusting the vector angle of the two one-dimensional gratings in combination, the light can be flexibly adjusted to form different pupil expansion directions in the decoupling area 120, so that the light can cover the entire decoupling area 120, which can increase the light output area of the light-guiding device, that is, each area and corner of the decoupling area 120 can emit light, which is conducive to obtaining a larger and more complete eyebox value. The human eye can see a clear and complete image in the entire field of view, thereby enhancing the user's visual experience.

In the light-guiding device provided in the application embodiment, each of the basic outcoupling units, see FIG. 2 to FIG. 5, for example, may include a first sub-outcoupling grating 121 and a second sub-outcoupling grating 122, and the two sub-outcoupling gratings are designed as one-dimensional gratings, and the vector angle of the two one-dimensional gratings can be flexibly adjusted according to specific needs (for example, 60 degrees), so that in the outcoupling area 120, the above-mentioned basic outcoupling unit can be used to perform two-dimensional pupil expansion in a specific direction according to a set angle on the light propagating to the outcoupling area 120, so that the light can completely cover the outcoupling area 120. Compared with the traditional two-dimensional grating, this is more flexible in adjusting the pupil expansion direction, and can avoid defects in the two-dimensional grating when expanding the pupil.

It should be noted that the light guide device of the embodiment of the present application includes a waveguide substrate 100 and an incoupling region 110 and an outcoupling region 120 disposed on the waveguide substrate 100. The two out-coupling regions 120 can be arranged on the same side surface of the waveguide substrate 100. Of course, the two can also be distributed on both sides of the waveguide substrate 100. In the embodiment of the present application, the relative position relationship between the coupling-in region 110 and the out-coupling region 120 is not limited, as long as it is possible to couple the light into the waveguide substrate 100 through the coupling-in region 110, and after the light is propagated to the out-coupling region 120 by total reflection in the waveguide substrate 100, the light can be coupled out through the out-coupling region 120.

The outcoupling region 120 may be provided with only two basic outcoupling units.

Of course, the decoupling area 120 may also be provided with more basic decoupling units.

For example, when multiple basic outcoupling units are provided, the multiple basic outcoupling units are arranged in an array of multiple rows and columns in the outcoupling region 120. Referring to Fig. 6, a rectangular array arrangement structure is shown.

Optionally, the outcoupling region 120 includes at least one basic outcoupling unit, and the basic outcoupling units can be distributed in the outcoupling region in any shape and distribution manner, so that the structural design of the entire light guide device is more flexible and has a higher degree of freedom.

The embodiment of the present application provides a diffraction optical waveguide design scheme, in which at least two basic out-coupling units are formed in the out-coupling area 120 by optimizing and combining one-dimensional gratings, and a two-dimensional pupil expansion and out-coupling function is realized in the out-coupling area 120. External light is coupled into the waveguide substrate through the coupling-in area and propagates to the basic out-coupling unit through total reflection. The basic out-coupling unit is a pupil expansion and out-coupling area, which can effectively expand the light in two different dimensional directions and finally cover all areas of the entire out-coupling area, thereby effectively increasing the light output area, so that the human eye can obtain a clear and complete image in the entire field of view, and can enhance the user's visual experience.

In some examples of the present application, referring to FIG. 2 to FIG. 5 , the first vector K1 and the second vector K2 form an angle of 60 degrees.

Specifically, in one of the basic outcoupling units, the first sub-outcoupling grating 121 and the second sub-outcoupling grating 122 are both designed as one-dimensional gratings, and both have grating vectors in a single direction; wherein the first sub-outcoupling grating 121, for example, has a first vector K1, and the second sub-outcoupling grating 122, for example, has a second vector K2. In an embodiment of the present application, the vector directions of the first vector K1 and the second vector K2 are different, but the two are designed to form an angle of 60 degrees. In this case, when the light in the waveguide substrate 100 propagates to the basic outcoupling unit, for example, it can expand in the horizontal and vertical dimensions and couple the light out of the waveguide substrate. In addition to the bottom 100, the light can completely cover the entire outcoupling area 120 after pupil expansion, so that each area of the entire outcoupling area 120 can emit light, effectively increasing the light output area to the light guide device.

In some examples of the present application, referring to FIG. 2 to FIG. 4 , in the basic outcoupling unit: the first sub-outcoupling grating 121 and the second sub-outcoupling grating 122 are located on the same surface of the waveguide substrate 100 and are arranged adjacent to each other.

In some examples of the present application, referring to FIG. 5 , the first sub-outcoupling grating 121 and the second sub-outcoupling grating 122 are respectively arranged on two surfaces of the waveguide substrate 100 , and are at least partially overlapped in the projection direction.

For example, the basic outcoupling unit can be arranged on the same surface of the waveguide substrate 100, wherein the first sub-outcoupling grating 121 and the second sub-outcoupling grating 122 contained therein are arranged close to each other, see Figures 2 to 4, and the specific arrangement method can be adjusted as needed.

Of course, the first sub-coupling grating 121 and the second sub-coupling grating 122 in the basic outcoupling unit can also be located on the upper and lower surfaces of the waveguide substrate 100 respectively, and their orthographic projections in the thickness direction of the waveguide substrate 100 form a partial overlap (coverage), see Figure 5.

The light-guiding device provided in the embodiment of the present application has a relatively flexible arrangement position of the basic outcoupling unit, which allows a higher degree of freedom in the structural design of the entire light-guiding device.

In some examples of the present application, referring to FIG. 2 to FIG. 5 , in the basic outcoupling unit, the first vector K1 of the first sub-outcoupling grating 121 and the second vector K2 of the second sub-outcoupling grating 122 form a mirror-symmetric structure.

Optionally, the symmetry axis of the first vector K1 and the second vector K2 can be arranged along the X-axis direction (see Figures 2, 4 and 5) or along the Y-axis direction (see Figure 3) on the decoupling region 120. The decoupling region 120 is located on the XY plane formed by the X-axis and the Y-axis.

Of course, the symmetry axes of the first vector K1 and the second vector K2 can also be inclined on the parallel plane where the decoupling area 120 is located, and the inclination angle can be flexibly designed as needed, such as 30 degrees or 45 degrees, etc. There is no limitation on this in the present application. As long as the first vector K1 and the second vector K2 form an angle of 60 degrees under mirror symmetry, the purpose of expanding the light and covering the entire decoupling area 120 can be achieved.

The light guide device provided in the embodiment of the present application has a very flexible pattern/structure design of the outcoupling region 120 thereon, so that the design freedom of the entire light guide device is higher and the scope of use is wider.

In an embodiment of the present application, the first sub-outcoupling grating 121 and the second sub-outcoupling grating 122 are both one-dimensional gratings, and the grating vector direction of the one-dimensional grating is perpendicular to the grating line, which is a periodically changing direction, and its length is equal to the reciprocal of the grating period. The two-dimensional pupil expansion effect formed by combining two one-dimensional gratings can improve the degree of freedom of the pupil expansion direction during two-dimensional pupil expansion.

2 to 5, in one of the basic outcoupling units, the first vector K1 of the first outcoupling grating 121 and the second vector K2 of the second outcoupling grating 122 are in different directions, and the two can form an angle of 60°. Since the first vector K1 and the second vector K2 are designed to be mirror-symmetrical, the grating lines of the first outcoupling grating 121 and the grating lines of the second outcoupling grating 122 should also be mirror-symmetrical from the outside.

Wherein, referring to FIG7 , the coupling region 110 is provided with a coupling grating 111, and the coupling grating 111 includes a one-dimensional grating, and the grating vector of the coupling grating 111 is a third vector K3; the angles between the first vector K1, the second vector K2 and the third vector K3 are 60 degrees to each other, and the first vector K1, the second vector K2 and the third vector K3 can form a closed equilateral triangle.

As shown in Fig. 7, the first vector K1, the second vector K2 and the third vector K3 need to jointly form a closed vector triangle, and the angles between the first vector K1, the second vector K2 and the third vector K3 are 60 degrees, that is, the vector triangle is an equilateral triangle. This design can ensure that the exit angle of the light when coupled out from the coupling-out region 120 is consistent with the incident angle of the light when coupled in through the coupling-in region 110, which is conducive to expanding the field of view of the light guide device.

It should be noted that, when there are two or more basic outcoupling units, the sum of the grating vectors of the incoupling grating and each of the basic outcoupling units should be zero.

In the light-guiding device of the embodiment of the present application, the light can first be incident on the first sub-outcoupling grating 121 and then on the second sub-outcoupling grating 122, or first be incident on the second sub-outcoupling grating 122 and then on the first sub-outcoupling grating 121, and the closure relationship in the above two cases needs to be consistent. If the vector angle between the input grating 111, the first sub-outcoupling grating 121 and the second sub-outcoupling grating 122 is not 60°, the closed triangles formed in the above two cases will be inconsistent, resulting in a large difference between the angle of the pupil-expanding outcoupling light and the incident angle, so that the user cannot see the complete image.

In the light guiding device of the embodiment of the present application, the periods of the coupling-in grating 111 , the first sub-coupling grating 121 and the second sub-coupling grating 122 are the same.

The waveguide substrate 100 is provided with an incoupling region 110 and an outcoupling region 120, wherein the incoupling region 110 is provided with an incoupling grating, and the outcoupling region 120 is provided with a basic outcoupling unit, and the basic outcoupling unit includes a first sub-outcoupling grating 121 and a second sub-outcoupling grating 122. The incoupling grating 111, the first sub-outcoupling grating 121 and the second sub-outcoupling grating 122 form an equilateral triangle with a closed vector angle of 60°, and the three have the same period, so as to ensure that the exit angle of the light when coupled out from the outcoupling region 120 is consistent with the incident angle of the light when coupled in through the incoupling region 110.

Optionally, the period range of the coupling-in grating 111 , the first sub-coupling grating 121 and the second sub-coupling grating 122 is 200 nm to 600 nm.

The one-dimensional grating within the above period range can be applied to most diffraction optical waveguide devices. Of course, those skilled in the art can also adjust the period of the grating in each region according to actual needs.

Optionally, the coupling-in grating 111 , the first sub-coupling grating 121 , and the second sub-coupling grating 122 are all one-dimensional gratings, and the one-dimensional gratings include any one of relief gratings, holographic gratings, and photonic crystal gratings.

Among them, the holographic grating is a grating made by holographic photography technology. Optical holography mainly uses the principle of optical coherence superposition. Simply put, it is a technology that adjusts the complex terms (time terms) to make the peaks and valleys of two light wave trains superimposed to achieve a high contrast in the coherent field. The coupling-in grating and/or coupling-out grating made by holographic grating processing will not generate ghost light when diffracting light, and the generated stray light is small, and the obtained graphic light resolution is high.

Photonic crystal grating is a regular optical structure made of periodically arranged media with different refractive indices. This material can block photons of a specific frequency due to its photonic band gap, thereby affecting the movement of photons. The coupling-in grating and/or coupling-out grating made of photonic crystal can select the wavelength of light and improve the grating diffraction effect.

The above-mentioned gratings are all diffraction gratings, and appropriate types of diffraction gratings can be selected and applied to the coupling-in region and/or coupling-out region of the light-guiding device as required, and this application does not impose any specific restrictions on this. In other words, the solution of this application does not impose any restrictions on the specific types of coupling-in gratings and coupling-out gratings, and has a wide range of applications.

In some examples of the present application, referring to FIG. 6 , the basic out-coupling unit is provided in plurality, and the plurality of basic out-coupling units are arranged in a matrix on at least one surface of the waveguide substrate 100 .

Referring to FIG6 , each basic outcoupling unit includes a first outcoupling sub-grating 121 and a second outcoupling sub-grating 122 arranged side by side, and a plurality of basic outcoupling units are arranged in a rectangular array along the horizontal direction and the vertical direction shown in FIG6 . In the horizontal direction, any two adjacent gratings are respectively the first outcoupling sub-grating 121 and the second outcoupling sub-grating 122, and similarly, in the vertical direction, any two adjacent gratings are also respectively the first outcoupling sub-grating 121 and the second outcoupling sub-grating 122. In other words, in the outcoupling region 120, any two adjacent sub-outcoupling units are respectively the first outcoupling sub-grating 121 and the second outcoupling sub-grating 122, and can form a basic outcoupling unit.

Please continue to refer to FIG6 , the propagation path of the light incident into the light guide device is as follows:

The light is incident into the waveguide substrate 100 through the coupling-in region 110 to generate a first diffracted light 001 propagating toward the basic coupling-out unit;

When the first diffracted light 001 first encounters the first outcoupling sub-grating 121, the second diffracted light 002 propagates to one side. When a part of the second diffracted light 002 encounters the adjacent second outcoupling sub-grating 122, the outcoupling light 011 is generated and emitted. Another part of the second diffracted light 002 continues to propagate and generates a third diffracted light 003 when encountering the first outcoupling sub-grating 121 again. The third diffracted light 003 has the same diffraction direction as the first diffracted light 001.

The light of the first diffracted light 001 that continues to propagate is transmitted to the second outcoupling sub-grating 122, generating a fourth diffracted light 004 that propagates to one side. When the fourth diffracted light enters the first outcoupling sub-grating 121 adjacent thereto, it generates an outcoupling light 011 and emits;

Finally, the light can cover the entire outcoupling region 120 .

The embodiment of the present application further provides a wearable device, wherein the wearable device comprises the light guide device and an optical machine as described above, wherein the optical machine is used to project light or an image into the light guide device.

The wearable device also includes a shell, and the light guide device and the optical machine are arranged in the shell.

The head mounted display device is, for example, an AR device. The AR device includes AR smart glasses or an AR smart helmet, etc., which is not limited in this application.

The specific implementation of the wearable device of the embodiment of the present application can refer to the above-mentioned light guide Therefore, the present invention at least has all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, which will not be described in detail here.

Although some specific embodiments of the present application have been described in detail by way of example, it should be understood by those skilled in the art that the above examples are only for illustration, not for limiting the scope of the present application. It should be understood by those skilled in the art that the above embodiments may be modified without departing from the scope and spirit of the present application. The scope of the present application is defined by the appended claims.

Claims (12)

A light-guiding device, characterized in that it comprises a waveguide substrate (100) and an incoupling region (110) and an outcoupling region (120) arranged on the waveguide substrate (100); The outcoupling region (120) is provided with at least two basic outcoupling units of a set shape, each of the basic outcoupling units comprising a first sub-outcoupling grating (121) and a second sub-outcoupling grating (122); The grating vector of the first sub-outcoupling grating (121) is a first vector K1, the grating vector of the second sub-outcoupling grating (122) is a second vector K2, and a predetermined angle is formed between the first vector K1 and the second vector K2; the light irradiated into the waveguide substrate (100) through the coupling-in region (110) is totally reflected in the waveguide substrate (100) and propagates to the basic outcoupling unit, and the basic outcoupling unit expands the pupil of the light in two different dimensional directions so that the light can cover the entire outcoupling region (120). The light guide device according to claim 1, characterized in that the first vector K1 and the second vector K2 form an angle of 60 degrees. The light-guiding device according to claim 1 is characterized in that, in the basic outcoupling unit: the first sub-outcoupling grating (121) and the second sub-outcoupling grating (122) are located on the same surface of the waveguide substrate (100) and are arranged adjacent to each other. The light-guiding device according to claim 1 is characterized in that, in the basic outcoupling unit: the first sub-outcoupling grating (121) and the second sub-outcoupling grating (122) are respectively arranged on two surfaces of the waveguide substrate (100), and are at least partially overlapped in the projection direction. The light-guiding device according to claim 1 is characterized in that, in the basic outcoupling unit: the first vector K1 of the first sub-outcoupling grating (121) and the second vector K2 of the second sub-outcoupling grating (122) form a mirror-symmetric structure. The light-guiding device according to claim 1, characterized in that the coupling-in region (110) A coupling-in grating (111) is provided, wherein the coupling-in grating (111) comprises a one-dimensional grating, and the grating vector of the coupling-in grating (111) is a third vector K3; The angles between the first vector K1 , the second vector K2 , and the third vector K3 are 60 degrees, and the first vector K1 , the second vector K2 , and the third vector K3 can form a closed equilateral triangle. The light-guiding device according to claim 6, characterized in that the periods of the coupling-in grating (111), the first sub-coupling grating (121) and the second sub-coupling grating (122) are the same. The light-guiding device according to claim 6, characterized in that the period range of the coupling-in grating (111), the first sub-coupling grating (121) and the second sub-coupling grating (122) is 200nm to 600nm. The light-guiding device according to claim 6 is characterized in that the coupling-in grating (111), the first sub-coupling grating (121) and the second sub-coupling grating (122) are all one-dimensional gratings, and the one-dimensional gratings include any one of a relief grating, a holographic grating and a photonic crystal grating. The light-guiding device according to claim 1 is characterized in that the basic outcoupling unit is provided in plurality, and the plurality of basic outcoupling units are arranged in a matrix on at least one surface of the waveguide substrate (100). The light-guiding device according to claim 10, characterized in that the light is incident into the waveguide substrate (100) through the coupling-in region (110) to generate a first diffracted light (001) propagating toward the basic coupling-out unit; When the first diffracted light (001) first encounters the first outcoupling sub-grating (121), a second diffracted light (002) is generated to propagate to one side, and when a part of the second diffracted light (002) encounters the adjacent second outcoupling sub-grating (122), an outcoupling light (011) is generated and emitted, and another Part of the second diffracted light (002) continues to propagate and generates third diffracted light (003) when encountering the first sub-coupling grating (121) again, and the third diffracted light (003) has the same diffraction direction as the first diffracted light (001); The light that continues to propagate from the first diffracted light (001) is transmitted to the second sub-coupling grating (122), generating fourth diffracted light (004) that propagates toward one side. When the fourth diffracted light enters the adjacent first sub-coupling grating (121), it generates coupling light (011) and emits. A wearable device, comprising: The light guide device according to any one of claims 1 to 11; and An optical machine is used to inject light or an image into the light guiding device.