Light guide device, optical module, and head-mounted display apparatus

Abstract

Provided in the embodiments of the present application are a light guide device, an optical module, and a head-mounted display apparatus. The light guide device comprises a light guide substrate and a coupling-in area and a coupling-out area which are disposed on the light guide substrate, wherein the coupling-out area is used for expanding and coupling out light from the coupling-in area. The coupling-out area comprises at least a first area, said first area being composed of at least two adjacent one-dimensional gratings; a target interval L may be formed between any two adjacent one-dimensional gratings, the target interval L satisfying 0≤L≤4 mm. By means of the optical solution provided in the embodiments of the present application, the processing difficulty of the coupling-out area can be reduced.

Description

Light guide devices, optical modules and head-mounted display devices

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on June 13, 2023, with application number 202310700976.9 and invention name “Light-guiding device, optical module and head-mounted display device”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The embodiments of the present application relate to the field of optical imaging technology. More specifically, the embodiments of the present application relate to a light guide device, an optical module, and a head-mounted display device. Background Art

[0003] In existing technologies, diffractive waveguide devices typically employ a two-dimensional grating design that combines pupil expansion with outcoupling. The light propagation path is such that light coupled into the waveguide expands in both directions upon 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 angle cannot be adjusted in either direction, vignetting will always occur in at least one corner of the field of view on the two-dimensional grating. This seriously affects the uniformity and integrity of the image displayed by the waveguide, and thus the user experience. Furthermore, the design of a two-dimensional grating is relatively complex, increasing production costs.

[0004] Summary of the Invention

[0005] The purpose of this application is to provide a new technical solution for a light-guiding device, an optical module, and a head-mounted display device.

[0006] In a first aspect, the present application provides a light guide device. The light guide device includes a light guide substrate and an incoupling region and an outcoupling region disposed on the light guide substrate;

[0007] In which, the outcoupling zone is used to expand the pupil and couple out the light from the coupling-in zone, the outcoupling zone includes at least a first area, and the first area is composed of at least two adjacent one-dimensional gratings. A target interval L can be formed between any two adjacent one-dimensional gratings, and the target interval L is 0≤L≤4mm.

[0008] Optionally, the first region is located in the middle of the outcoupling region, and within the first region, grating vectors of any two adjacent one-dimensional gratings form a mirror-symmetrical structure and their grating vectors form a target angle.

[0009] Optionally, the target angle is 50° to 70°.

[0010] Optionally, the first region includes 2 to 8 one-dimensional gratings, and the number of the one-dimensional gratings is an even number.

[0011] Optionally, the outcoupling region further includes a second region and a third region, the second region and the third region are located on two opposite sides of the first region, and the second region and the third region include a one-dimensional grating or a two-dimensional grating.

[0012] Optionally, the first region includes a first grating, a second grating, a third grating and a fourth grating that are adjacently arranged, and the first grating, the second grating, the third grating and the fourth grating are all one-dimensional gratings;

[0013] The first grating and the second grating are located in the middle of the first area, the grating vectors of the first grating and the second grating form a mirror-symmetrical structure, and the target angle formed by the grating vectors of the two is 50° to 70°;

[0014] The third grating is located on a side of the first grating away from the second grating, the fourth grating is located on a side of the second grating away from the first grating, the third grating has the same grating vector as the second grating, and the fourth grating has the same grating vector as the first grating.

[0015] Optionally, the outcoupling region further includes a second region and a third region, the second region and the third region are respectively arranged on two opposite sides of the first region, the second region includes a fifth grating, and the third region includes a sixth grating;

[0016] The fifth grating and the sixth grating are one-dimensional gratings. The fifth grating has the same grating vector as the first grating, and the sixth grating has the same grating vector as the second grating.

[0017] Optionally, there are intervals between the first grating and the second grating, between the first grating and the third grating, between the second grating and the fourth grating, between the third grating and the fifth grating, and between the fourth grating and the sixth grating.

[0018] Optionally, the coupling-in region is provided with a coupling-in grating, which is used to couple light into the light-guiding substrate and cause the light to be totally reflected in the light-guiding substrate and propagate to the coupling-out region; the coupling-in grating is a one-dimensional grating and has a first vector K1, and two adjacent one-dimensional gratings in the first region respectively have a second vector K2 and a third vector K3, and the first vector K1, the second vector K2 and the third vector K3 constitute an isosceles triangle with a vector angle of 50° to 70°.

[0019] In a second aspect, the present application provides an optical module. The optical module includes:

[0020] The light guide device according to the first aspect; and

[0021] An optical machine is used to project light or an image into the light guide device.

[0022] In a third aspect, the present application provides a head-mounted display device. The head-mounted display device includes:

[0023] a housing; and

[0024] The optical module as described in the second aspect.

[0025] The beneficial effects of this application are:

[0026] According to the light-guiding device provided in the embodiment of the present application, which is a diffraction light waveguide solution, a two-dimensional pupil expansion and outcoupling function is achieved by combining at least two one-dimensional gratings in the outcoupling area. When the light from the incoupling area propagates to the outcoupling area, the light can be effectively expanded in two different dimensional directions and can cover all positions of the entire outcoupling area, which can increase the light-emitting area, so that the human eye can obtain a clear and complete image within a larger field of view, thereby improving the user's visual experience.

[0027] Other features and advantages of the present specification will become apparent from the following detailed description of exemplary embodiments of the present specification with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] 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 drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only part of the drawings of the present application. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without any creative work.

[0029] FIG1 is a schematic structural diagram of a light guide device provided in an embodiment of the present application;

[0030] FIG2 is a schematic diagram of a grating vector closed structure of a light guide device provided in an embodiment of the present application;

[0031] FIG3 is a schematic diagram of the structure of the first region of the light guide device provided in an embodiment of the present application;

[0032] FIG4 is a second structural schematic diagram of the first region of the light guide device provided in an embodiment of the present application;

[0033] FIG5 is a third structural diagram of the first region of the light guide device provided in an embodiment of the present application;

[0034] FIG6 is a top view of a light guide device according to an embodiment of the present application;

[0035] FIG7 is a second top view of the light guide device provided in an embodiment of the present application.

[0036] Explanation of the accompanying drawings: 1. Light-guiding substrate; 2. Coupling-in region; 3. Coupling-out region; 31. First grating; 32. Second grating; 33. Third grating; 34. Fourth grating; 35. Fifth grating; 36. Sixth grating; 301. First region; 01. First diffraction ray; 02. Second diffraction ray; 03. Third diffraction ray; 04. Fourth diffraction ray; 05. Coupling-out ray; 06. Fifth diffraction ray. DETAILED DESCRIPTION

[0037] 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 arrangements of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present application.

[0038] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the present disclosure, its application, or uses.

[0039] Techniques and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the techniques and equipment should be considered part of the specification.

[0040] 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.

[0041] It should be noted that like reference numerals and letters refer to like items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0042] The light guide device, optical module and head-mounted display device provided in the embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0043] Among various head-mounted display devices, AR devices, for example, typically include a microdisplay and an optical module. Common optical components used in AR device optical modules include prisms, freeform lenses, and optical waveguides. Among these optical components, optical waveguides include geometric waveguides and diffractive waveguides. Diffractive waveguides are widely used in AR devices due to their excellent optical performance.

[0044] According to one embodiment of the present application, a light guide device is provided. The light guide device is, for example, an optical waveguide device, such as a diffraction optical waveguide. The light guide device provided in the embodiment of the present application can be used in, for example, a wearable device.

[0045] 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.

[0046] The light guide device provided in an embodiment of the present application, as shown in FIG1 , includes a light guide substrate 1 and an incoupling region 2 and an outcoupling region 3 provided on the light guide substrate 1. The outcoupling region 3 is configured to expand the pupil of light from the incoupling region 2 and couple it out. Referring to FIG3 to FIG7 , the outcoupling region 3 includes at least a first region 301, and the first region 301 is composed of at least two adjacent one-dimensional gratings. A target spacing L can be formed between any two adjacent one-dimensional gratings, and the target spacing L is 0≤L≤4mm.

[0047] It should be noted that, in the first region 301 , two adjacent one-dimensional gratings may form a basic grating unit.

[0048] According to the light-guiding device provided in the above-mentioned embodiment of the present application, a coupling-in area 2 and a coupling-out area 3 are respectively provided on the light-guiding substrate 1. External light, such as light with image information projected by an optical machine, can enter the light-guiding substrate 1 through the coupling-in area 2, and the light will propagate toward the coupling-out area 3 in the light-guiding substrate 1 in a total reflection manner. When the light propagates to the coupling-out area 3 and encounters the first area 301, the first area 301 can expand the pupil of the light in two different dimensional directions, see Figure 6, and finally make the light fill the first area 301, so that the light output area of ​​the coupling-out area 3, especially the first area 301, can be increased, thereby enhancing the user's visual experience.

[0049] The traditional two-dimensional grating pupil expansion and outcoupling method cannot achieve the effect of making the light spread across the entire outcoupling area. 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. During the pupil expansion process, the light cannot propagate to certain locations in the outcoupling area. There will always be some corners with dark corners of the field of view, resulting in light emitting from one part of the outcoupling area and possibly not from another part. The human eye moves within a certain range and needs to be able to see the light during movement. Therefore, it can be seen that the two-dimensional grating pupil expansion will limit the range of use of the human eye, that is, the eyebox is smaller. In particular, when the center area of ​​the outcoupling area uses a two-dimensional grating for pupil expansion, the small eyebox is particularly obvious, and good imaging effects cannot be achieved.

[0050] In the light-guiding device provided in an embodiment of the present application, the outcoupling region 3 is designed to include a first region 301. At least two adjacent one-dimensional gratings are employed within the first region 301. A target spacing can be designed between the two adjacent one-dimensional gratings. This target spacing, for example, is less than 4 mm, i.e., less than the pupil diameter of the human eye. This facilitates enlarging the eyebox, particularly the lateral eyebox. It should be noted that when the target spacing is greater than 4 mm, the image perceived by the human eye will be incomplete and incomplete.

[0051] The first region 301 utilizes a pupil expansion design combining two one-dimensional gratings. This design has the advantage that each one-dimensional grating has a single vector direction. By adjusting the vector angle between two adjacent one-dimensional gratings, the pupil expansion direction of the light can be flexibly adjusted, ensuring that the light covers the first region 301 as fully as possible. This allows light to be emitted from every part and corner of the first region 301, resulting in a larger and more complete eyebox value. The human eye can see a clear and complete image across the entire field of view, thereby enhancing the user's visual experience.

[0052] The light-guiding device of the embodiment of the present application includes a light-guiding substrate 1 and an in-coupling region 2 and an out-coupling region 3 provided on the light-guiding substrate 1. The in-coupling region 2 and the out-coupling region 3 can be provided on the same side surface of the light-guiding substrate 1, as shown in FIG1 . Of course, the in-coupling region 2 and the out-coupling region 3 can also be distributed on both sides of the light-guiding substrate 1. The relative positional relationship between the in-coupling region 2 and the out-coupling region 3 is not limited in the embodiment of the present application, as long as it is possible to couple light into the light-guiding substrate 1 through the in-coupling region 2, propagate to the out-coupling region 3 by total reflection in the light-guiding substrate 1, and then couple the light out through the out-coupling region 3.

[0053] Optionally, in the light-guiding device provided in the embodiment of the present application, the light-guiding substrate 1 may be a single-layer color waveguide structure or a multi-layer color waveguide structure, and the embodiment of the present application does not impose any limitation on this.

[0054] 3 to 5 , there may be various combinations of the two one-dimensional gratings in the first region 301 , which are not limited in the embodiments of the present application.

[0055] In addition, forming a two-dimensional pupil expansion effect by combining two one-dimensional gratings in the first region 301 of the outcoupling region 3 can improve the degree of freedom of pupil expansion direction during two-dimensional pupil expansion.

[0056] In some examples of the present application, referring to FIG6 and FIG7 , the first region 301 is located in the middle of the outcoupling region 3 . Within the first region 301 , the grating vectors of any two adjacent one-dimensional gratings form a mirror-symmetrical structure and the grating vectors of the two form a target angle.

[0057] According to the above example, the first area 301 is located in the middle of the outcoupling area 3, for example, and can expand the pupil of the light in the central field of view, and the light after pupil expansion can cover the first area 301, thereby improving the imaging quality of the central field of view.

[0058] In the light-guiding device provided in the embodiments of the application, the first region 301 is designed to include at least two one-dimensional gratings, and the two one-dimensional gratings can be arranged adjacently and spaced apart. To achieve a better pupil expansion effect, the angle range formed by the grating vectors of the two one-dimensional gratings can be controlled. In this way, in the first region 301, light can be caused to expand the pupil in a two-dimensional manner in a specific direction according to a set angle, so that the light can more completely cover the first region 301, thereby avoiding defects in pupil expansion caused by the two-dimensional grating.

[0059] The first region 301 can be distributed in any shape and position in the outcoupling region 3 , making the structural design of the entire light guide device more flexible and more free. As a preferred embodiment of the present invention, the first region 301 is located in the center of the outcoupling region 3 .

[0060] In the first region 301 , the grating vectors of the two adjacent one-dimensional gratings form a mirror-symmetrical structure. Referring to FIG. 3 to FIG. 5 , the symmetry axes of the two one-dimensional gratings may be along different directions, which is not limited in the present application.

[0061] Optionally, the target angle is 50° to 70°.

[0062] Taking the example of the first region 301 including two adjacent and spaced-apart one-dimensional gratings, see Figure 4. The grating vector angle of the two one-dimensional gratings can be designed to be 50° to 70°, for example. In this case, when the light in the light-guiding substrate 1 propagates to meet the first region 301, it can expand along two different dimensions and cover the first region 301 as much as possible, and each part of the first region 301 can emit light.

[0063] The first region 301 may include, for example, 2 to 8 one-dimensional gratings, and the number of the one-dimensional gratings is an even number.

[0064] The size of the first region 301 can be reasonably designed according to the size of the outcoupling region 3. The first region 301 can occupy the entire outcoupling region 3 or be a partial region of the entire outcoupling region 3.

[0065] For example, the first region 301 is the middle region of the outcoupling region 3. A certain number of one-dimensional gratings can be designed according to the size of the first region 301. Based on the typical size of the outcoupling region 3, two to eight one-dimensional gratings can be provided in the middle region thereof, so that light can cover the entire first region 301 without causing any vignetting in the field of view.

[0066] The one-dimensional gratings in the first region 301 are designed to be combined in pairs to achieve two-dimensional pupil expansion. In order to achieve a better pupil expansion effect, it is more preferred that the number of the one-dimensional gratings is an even number.

[0067] In some examples of the present application, referring to Figures 6 and 7, the outcoupling region 3 also includes a second region and a third region, the second region and the third region are located on two opposite sides of the first region 301, and the second region and the third region include a one-dimensional grating or a two-dimensional grating.

[0068] According to the above example, in addition to the first region 301, the outcoupling region 3 may also include a second region and a third region located on the left and right sides of the first region 301. Referring to Figures 6 and 7, the second region and the third region are located at the edges of the outcoupling region 3. A single or multiple two-dimensional gratings, or multiple one-dimensional gratings, may be used in these two regions to expand the pupil and couple out light from the edge of the field of view, thereby adjusting the imaging condition of the edge of the field of view.

[0069] In one example of the present application, referring to FIG6 , the first region 301 includes a first grating 31, a second grating 32, a third grating 33, and a fourth grating 34, each of which is adjacent to each other. The first grating 31, the second grating 32, the third grating 33, and the fourth grating 34 are all one-dimensional gratings. The first grating 31 and the second grating 32 are located in the center of the first region 301. The grating vectors of the first grating 31 and the second grating 32 form a mirror-symmetric structure, and the target angle formed by the grating vectors of the first grating 31 and the second grating 32 is 50° to 70°. The third grating 33 is located on the side of the first grating 31 away from the second grating 32, and the fourth grating 34 is located on the side of the second grating 32 away from the first grating 31. The third grating 33 and the second grating 32 have the same grating vector, and the fourth grating 34 has the same grating vector as the first grating 31.

[0070] According to the above example, referring to FIG6 , FIG6 shows the optical behavior when the interval between the one-dimensional gratings in the first region 301 is 0, specifically as follows:

[0071] The coupling-in region 2 receives light projected by an external optical machine and couples the light into the light-guiding substrate 1, generating a first diffraction light ray 01 and a second diffraction light ray 02 that propagate toward the coupling-out region 3. After the first diffraction light ray 01 and the second diffraction light ray 02 are incident on the first region 301, upon encountering the combined one-dimensional grating, they propagate to one side as a third diffraction light ray 03 and a fourth diffraction light ray 04, and continue to propagate in the original direction, thereby achieving an effect equivalent to two-dimensional pupil expansion.

[0072] Due to symmetry, only the fourth diffracted ray 04 is described here. When the fourth diffracted ray 04 is incident on the adjacent one-dimensional grating within the first region 301, it generates an outcoupled ray 05 and continues to propagate in its original direction. The fourth diffracted ray 04 continues to propagate, and upon encountering a grating with the same vector orientation as the first grating, it generates a fifth diffracted ray 06 and continues to propagate in its original direction. The diffraction direction of the fifth diffracted ray 06 is the same as that of the second diffracted ray 02. Ultimately, the light propagating to both sides covers the entire first region 301, and even the entire outcoupled zone 3.

[0073] According to the above example, referring to Figure 6, the outcoupling region 3 also includes a second region and a third region, and the second region and the third region are respectively arranged on two opposite sides of the first region 301, the second region includes a fifth grating 35, and the third region includes a sixth grating 36; the fifth grating 35 and the sixth grating 36 are one-dimensional gratings, the fifth grating 35 has the same grating vector as the first grating 31, and the sixth grating 36 has the same grating vector as the second grating 32.

[0074] One-dimensional gratings are provided in both the second and third regions, but with different grating vector directions. The one-dimensional grating in the second region can form a basic grating unit with the one-dimensional grating in the first region 301 near the second region, thereby achieving a two-dimensional pupil expansion effect. Similarly, the one-dimensional grating in the third region can form a basic grating unit with the one-dimensional grating in the first region 301 near the third region, thereby also achieving a two-dimensional pupil expansion effect. This achieves pupil expansion and light outcoupling in the peripheral field of view.

[0075] According to the above example, in a more preferred example, referring to Figure 7, there are gaps between the first grating 31 and the second grating 32, between the first grating 31 and the third grating 33, between the second grating 32 and the fourth grating 34, between the third grating 33 and the fifth grating 35, and between the fourth grating 34 and the sixth grating 36.

[0076] The area for achieving two-dimensional pupil expansion is composed of a combination of one-dimensional grating intervals, and the interval is controlled to be less than 4mm. The eyebox can be enlarged. Referring to the solution shown in Figure 7, the lateral eyebox can be increased. However, it should be noted that the interval cannot be greater than 4mm, otherwise some areas may not be visible to the human eye.

[0077] In some examples of the present application, referring to Figures 1, 6, and 7, the coupling-in region 2 is provided with a coupling-in grating, which is used to couple light into the light-guiding substrate 1 and cause the light to be totally reflected within the light-guiding substrate 1 and propagate to the coupling-out region 3. The coupling-in grating is a one-dimensional grating and has a first vector K1. Two adjacent one-dimensional gratings in the first region 301 respectively have a second vector K2 and a third vector K3. The first vector K1, the second vector K2, and the third vector K3 form an isosceles triangle with an included angle of 50° to 70°, as shown in Figure 2.

[0078] Two adjacent gratings in the first region 301 may form a basic grating unit.

[0079] According to the above example, two adjacent one-dimensional gratings within the first region 301 each have a second vector K2 and a third vector K3. The first vector K1, the second vector K2, and the third vector K3 form an isosceles triangle with an included angle of 50° to 70°. This design ensures that the angle of light emitted from the outcoupling region 3 is consistent with the angle of light incident when coupled into the incoupling region 2, thereby expanding the field of view of the light guide device.

[0080] In the light-guiding device provided in the embodiment of the present application, the diffraction gratings in the coupling-in region 2 and the coupling-out region 3 may be volume holographic gratings, surface relief gratings or photonic crystals, etc.

[0081] The above-mentioned gratings are all diffraction gratings. A suitable type of diffraction grating can be selected and applied to the coupling-in region and / or coupling-out region of the light guide device as required, and this application does not impose any specific limitation on this.

[0082] According to another aspect of an embodiment of the present application, an optical module is provided, comprising the light guide device described above and an optical engine, wherein the optical engine is configured to project light or an image into the light guide device.

[0083] The imaging light emitted by the optical machine is projected onto the coupling-in area 2 of the light-guiding device. Referring to FIG2 , the coupling-in area 2 can be used to couple the imaging light emitted by the machine into the light-guiding substrate 1, and enable the coupled light to propagate to the coupling-out area 3 in a state of total reflection. The coupling-out area 3 can dilate the pupil of the propagated light and couple it out. Among them, the area for realizing two-dimensional pupil expansion introduced in the coupling-out area 3 is composed of a combination of one-dimensional grating intervals, and the interval distance is between 0 and 4 mm.

[0084] The light emitted by the optical engine should be able to cover the entire coupling-in area 2 .

[0085] The light emitted by the optical machine can be monochromatic light or polychromatic light.

[0086] According to another aspect of the embodiments of the present application, a head-mounted display device is provided, comprising a housing and the optical module as described above.

[0087] The head-mounted display device is, for example, an AR head-mounted device, including AR glasses or an AR helmet, etc., and the embodiments of the present application do not impose specific restrictions on this.

[0088] The specific implementation of the optical module and head-mounted display device of the embodiments of the present application can refer to the above-mentioned embodiments of the light guide device, and therefore at least have all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, which will not be repeated here one by one.

[0089] The above embodiments focus on the differences between the various embodiments. As long as the different optimization features between the various embodiments are not contradictory, they can be combined to form a better embodiment. Considering the simplicity of the text, they will not be repeated here.

[0090] 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 for illustration only and are not intended to limit the scope of the present application. It should be understood by those skilled in the art that the above examples 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

1. A light guide device, characterized in that: It comprises a light-guiding substrate (1) and an incoupling region (2) and an outcoupling region (3) arranged on the light-guiding substrate (1); The outcoupling zone (3) is used to expand the pupil of the light from the coupling-in zone (2) and couple it out, the outcoupling zone (3) includes at least a first area (301), and the first area (301) is composed of at least two adjacent one-dimensional gratings, and a target interval L can be formed between any two adjacent one-dimensional gratings, and the target interval L is 0≤L≤4mm.

2. The light guide device according to claim 1, characterized in that: The first region (301) is located in the middle of the outcoupling region (3), and within the first region (301), grating vectors of any two adjacent one-dimensional gratings form a mirror-symmetric structure and the grating vectors of the two form a target angle.

3. The light guide device according to claim 2, characterized in that: The target angle is 50° to 70°.

4. The light guide device according to claim 1, characterized in that: The first region (301) includes 2 to 8 one-dimensional gratings, and the number of the one-dimensional gratings is an even number.

5. The light guide device according to any one of claims 1 to 4, characterized in that: The outcoupling region (3) further comprises a second region and a third region, wherein the second region and the third region are arranged on two opposite sides of the first region (301), and the second region and the third region comprise a one-dimensional grating or a two-dimensional grating.

6. The light guide device according to claim 5, characterized in that: The first region (301) comprises a first grating (31), a second grating (32), a third grating (33) and a fourth grating (34) which are arranged adjacent to each other, and the first grating (31), the second grating (32), the third grating (33) and the fourth grating (34) are all one-dimensional gratings; The first grating (31) and the second grating (32) are located in the middle of the first area (301), the grating vectors of the first grating (31) and the second grating (32) form a mirror-symmetrical structure, and the target angle formed by the grating vectors of the two is 50° to 70°; The third grating (33) is located on a side of the first grating (31) away from the second grating (32), the fourth grating (34) is located on a side of the second grating (32) away from the first grating (31), the third grating (33) has the same grating vector as the second grating (32), and the fourth grating (34) has the same grating vector as the first grating (31).

7. The light guide device according to claim 6, characterized in that: The outcoupling region (3) further comprises a second region and a third region, the second region and the third region are arranged on two opposite sides of the first region (301), the second region comprises a fifth grating (35), and the third region comprises a sixth grating (36); The fifth grating (35) and the sixth grating (36) are one-dimensional gratings. The fifth grating (35) has the same grating vector as the first grating (31), and the sixth grating (36) has the same grating vector as the second grating (32).

8. The light guide device according to claim 7, characterized in that: There are spaces between the first grating (31) and the second grating (32), between the first grating (31) and the third grating (33), between the second grating (32) and the fourth grating (34), between the third grating (33) and the fifth grating (35), and between the fourth grating (34) and the sixth grating (36).

9. The light guide device according to claim 1, characterized in that: The coupling-in region (2) is provided with a coupling-in grating, and the coupling-in region (2) is used to couple light into the light-guiding substrate (1) and to make the light be totally reflected in the light-guiding substrate (1) and propagate to the coupling-out region (3); The coupling grating is a one-dimensional grating and has a first vector K1. Two adjacent one-dimensional gratings in the first area have a second vector K2 and a third vector K3 respectively. The first vector K1, the second vector K2 and the third vector K3 form an isosceles triangle with a vector angle of 50° to 70°.

10. An optical module, characterized in that: include: The light guide device according to any one of claims 1 to 9; as well as An optical machine is used to project light or an image into the light guiding device.

11. A head mounted display device, characterized in that: include: case; as well as The optical module as claimed in claim 10.

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