Optical device and near-eye display device

Abstract

Provided in the present application are an optical device and a near-eye display device. The optical device comprises a light guide member, a light coupling-in device arranged at one end of the light guide member, and a light coupling-out device arranged at the opposite end of the light guide member, wherein the light coupling-out device comprises a plurality of surfaces arranged in parallel, each surface being obliquely arranged relative to a total internal reflection surface of the light guide member, the plurality of surfaces being spaced apart in the lengthwise direction of the light guide member, and the spacing at which the plurality of surfaces are arranged gradually increases in a first direction; the first direction is a direction away from the light coupling-in device; and in the first direction, the surface farthest away from the light coupling-in device is a total reflection surface, and the remaining surfaces are partially transmissive and partially reflective sheets. In the technical solution, the spacing at which the surfaces are arranged is adjusted, such that the occurrence of light penetrating adjacent surfaces during the exiting of the light from the light guide member is reduced, and the light exiting effect is improved, thereby increasing the light transmittance, and improving the light uniformity, such that the usage effect of the optical device is improved.

Description

Optical device and near-eye display device

[0001] This application claims priority to a Chinese patent application filed with the Patent Office of China on March 5, 2024, with application number 202410251917.2 and application name “An optical device and near-eye display device,” the entire contents of which are incorporated herein by reference. Technical Field

[0002] The present application relates to the field of optical technology, and in particular to an optical device and a near-eye display device. Background Art

[0003] Existing light-guiding optical elements need to be collimated before being incident on a waveguide for propagation, and after being coupled out of the waveguide, they enter the human eye for imaging.

[0004] When coupling light out of a light guide, a light outcoupling device is often used to couple the light out of the light guide through reflection. Existing light outcoupling devices often utilize an array of reflective surfaces that are evenly spaced and arranged, extending across the surface. However, such systems can exhibit significant transmittance drops and uneven light intensity distribution at different locations. Summary of the Invention

[0005] The present application provides an optical device and a near-eye display device to improve the use effect of the optical device.

[0006] The present application provides an optical device, which includes: a light guide, a light coupling device arranged at one end of the light guide, and a light coupling device arranged at the other end opposite to the light guide; wherein,

[0007] The light outcoupling device includes a plurality of parallel surfaces, each of which is inclined relative to the total internal reflection surface of the light guide; the plurality of surfaces are spaced apart along the length of the light guide, wherein the spacing between the plurality of surfaces gradually increases along a first direction; the first direction is a direction away from the light incoupling device;

[0008] Along the first direction, the surface farthest from the light coupling device is a total reflection surface, and the remaining surfaces are partially transmissive and partially reflective sheets.

[0009] In the above technical solution, by adjusting the arrangement spacing of the surfaces, the situation where light passes through adjacent surfaces during the process of emitting from the light guide is reduced, thereby improving the effect of light when emitting, thereby improving the transmittance of light, improving the uniformity of light, and thus improving the use effect of the optical device.

[0010] In a specific embodiment, along the first direction, among any adjacent surfaces, the surface close to the light coupling device is the first surface, and the surface far from the light coupling device is the second surface; then the distance between the first surface and the second surface satisfies:

[0011] Along the second direction, the edge light reflected from one end of the second surface away from the light emitting surface of the light guide does not pass through the first surface or only passes through the end point of the first surface close to the light emitting surface of the light guide on the path of exiting the light guide; wherein, the second direction is the thickness direction of the light guide.

[0012] In a specific embodiment, the interval H between any two adjacent surfaces satisfies:

[0013] Wherein, L is the dimension of the surface along the second direction, which is the thickness direction of the light guide; n is the refractive index of the light guide; a is the angle between the surface and the total internal reflection surface of the light guide; b is the emission angle of the edge light when it passes through the first surface close to the end point of the light output surface of the light guide; k is the processing error, which is between -0.3 mm and +0.3 mm.

[0014] In a specific possible implementation manner, the surface is embedded in the light guide.

[0015] In a specific embodiment, the total internal reflection surface includes a first total internal reflection surface and a second total internal reflection surface arranged parallel to each other; the light coupled into the light guide member by the light coupling device is totally reflected by the first total internal reflection surface and the second total internal reflection surface to the light coupling device; wherein,

[0016] Along the second direction, the plurality of surfaces in the light outcoupling device are spaced apart from the first total internal reflection surface and the second total internal reflection surface by gaps.

[0017] In a specific embodiment, the gap between the surface and the first total internal reflection surface is equal to the gap between the surface and the second total internal reflection surface.

[0018] In a specific embodiment, along the second direction, the size of the surface and the size between the first total internal reflection surface and the second total internal reflection surface satisfy:

[0019] The light passing through the surface close to the first total internal reflection surface is reflected by the first total internal reflection surface and transmits through the surface, and then reflected by the second total internal reflection surface to another adjacent surface without transmitting through the surface again.

[0020] In a specific embodiment, along the second direction, the vertical distance between the first total internal reflection surface and the second total internal reflection surface is d; the vertical distance between the two ends of the surface is L; then:

[0021] In a second aspect, a near-eye display device is provided, comprising a light generator and any one of the optical devices described above; wherein,

[0022] The light emitted by the light generator is incident on the light guide of the optical device.

[0023] In the above technical solution, by adjusting the arrangement spacing of the surfaces, the situation where light passes through adjacent surfaces during the process of emitting from the light guide is reduced, thereby improving the effect of light during emission and further improving the use effect of the optical device.

[0024] In a specific embodiment, the light generator is any one of an optical collimator, a light source generator assembly, and an image source. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] FIG1 is a schematic diagram of a usage scenario of an optical component in the prior art;

[0026] FIG2 is a schematic diagram of light outcoupling of a light guide in the prior art;

[0027] FIG3 is a schematic structural diagram of an optical device provided in an embodiment of the present application;

[0028] FIG4 is a schematic diagram showing the relationship between surfaces of an optical device provided in an embodiment of the present application;

[0029] FIG5 is a schematic diagram of a surface arrangement provided in an embodiment of the present application;

[0030] FIG6 is a schematic structural diagram of another optical device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solutions and advantages of this application clearer, this application will be further described in detail below with reference to the accompanying drawings.

[0032] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in one or more embodiments of this specification should have the usual meanings understood by people with ordinary skills in the field to which this disclosure belongs. The "first", "second" and similar words used in one or more embodiments of this specification do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative position relationships. When the absolute position of the object being described changes, the relative position relationship may also change accordingly.

[0033] To facilitate understanding of the optical device provided in the embodiments of the present application, its application scenario is first described. The display device provided in the embodiments of the present application is applied to different near-eye display systems such as AR (Augmented Reality, enhanced display technology) or VR (Virtual Reality, virtual display technology) to realize virtual display. However, current near-eye display systems generally suffer from light loss when light is coupled out of the light guide, which affects the customer's viewing experience.

[0034] As shown in FIG1 , FIG1 shows a schematic diagram of an application scenario of an optical device in the prior art. The existing optical device includes a light guide 1, a light coupling device 2, a light coupling device 3, and a light generator 9. Among them, the light generator 9 is used to emit light for displaying an image. The light coupling device 2 is used to couple the light emitted by the light generator 9 into the light guide 1. The light guide 1 is used to propagate light, and it has two oppositely arranged total internal reflection surfaces. The light in the light guide 1 can propagate light through total internal reflection of the total internal reflection surfaces. The light coupling device 3 is used to couple the light in the light guide 1 out to the user's eyes, so that the user can observe the image displayed by the light generator.

[0035] Referring also to FIG. 2 , the light outcoupling device 3 includes multiple parallel surfaces. When coupling light out, these multiple parallel surfaces can easily cause the outcoupled light to pass through adjacent surfaces. For example, in FIG. 2 , the surfaces include a first surface 4, a second surface 5, and a third surface 6. First surface 4 is the surface away from the light outcoupling device 3. During the propagation of the light outcoupled through first surface 4, some light passes only through second surface 5 (as indicated by the dashed line in FIG. 2 ), some light passes through both second surface 5 and third surface 6 (as indicated by the dotted line in FIG. 2 ), and some light is directly coupled out of the light guide 1 (as indicated by the solid line in FIG. 2 ). This results in uneven energy of the light outcoupled from first surface 4, affecting the user's viewing experience.

[0036] To this end, an embodiment of the present application provides an optical device for improving the viewing angle effect and miniaturization of a display device, which will be described in detail below with reference to specific drawings and embodiments.

[0037] Referring to FIG3 , FIG3 shows a schematic structural diagram of an optical device provided in an embodiment of the present application. The optical device provided in an embodiment of the present application includes a light guide 10, a light coupling device 20, and a light coupling device 30. The light guide 10 is used to propagate light by total internal reflection. The light guide 10 is a long strip-shaped structure having total internal reflection surfaces on two opposite sides. The light incident on the light guide 10 propagates in the light guide 10 by total reflection through the two total internal reflection surfaces. The light coupling device 20 and the light coupling device 30 are arranged at both ends of the light guide 10, and are used to couple light from outside the light guide 10 into the light guide 10 for propagation, and to couple light in the light guide 10 out of the light guide 10 (coupling out from the light output surface of the light guide 10).

[0038] To facilitate understanding of the optical device provided in the embodiments of this application, we first define the first and second directions. The first direction is the lengthwise direction of the light guide 10. In this embodiment, the first direction is from the light incoupling device 20 toward the light outcoupling device 30, i.e., the first direction is away from the light incoupling device 20. The second direction is the thickness direction of the light guide 10, i.e., the alignment direction of the two total internal reflection surfaces. As shown in Figure 3, the first direction is perpendicular to the second direction.

[0039] Continuing with FIG3 , the light coupling device 20 is used to couple light emitted by the light generator into the light guide 10. The light coupling device 20 comprises a surface that is inclined relative to the total internal reflection surface. When light enters the light guide 10, it is reflected by the light coupling device 20 onto the total internal reflection surface of the light guide 10. Thereafter, the light is reflected by the two total internal reflection surfaces to propagate within the light guide 10. The configuration of the light coupling device 20 will not be further described in this application; it is sufficient that the light coupling device 20 couples light from outside the light guide 10 into the light guide 10.

[0040] When light guide 10 propagates light, it does so by total reflection on two total internal reflection surfaces. Exemplarily, the total internal reflection surfaces include a first total internal reflection surface 11 and a second total internal reflection surface 12, which are arranged parallel to each other. Light coupled into light guide 10 via light coupling device 20 is then totally reflected by first and second total internal reflection surfaces 11, 12 to light coupling device 30. First total internal reflection surface 11 and light exit surface 12 are located on the same side as the light guide 10.

[0041] The light outcoupling device 30 is positioned opposite the light incoupling device 20, and the two are arranged at opposite ends of the light guide 10. The light outcoupling device 30 is used to couple light out to the user's eyes so that the user can see the light emitted by the light generator. In a specific configuration, the light outcoupling device 30 includes multiple surfaces 31. When the multiple surfaces 31 are arranged, their arrangement direction is spaced apart along the length direction of the light guide 10. Among the multiple surfaces 31, along a first direction, the surface 31 farthest from the light incoupling device 20 is a fully reflective surface 31, and the remaining surfaces 31 are partially transmissive and partially reflective surfaces. Taking the five surfaces 31 shown in Figure 3 as an example, the surface 31 farthest from the light incoupling device 20 is a fully reflective surface, while the remaining four surfaces 31 are semi-transmissive and semi-reflective surfaces. Of course, in the embodiment of the present application, the surface 31 farthest from the light incoupling device 20 can also be a partially reflective and partially transmissive surface, but its reflectivity is higher than its transmittance.

[0042] Furthermore, the multiple surfaces 31 are all inclined relative to the total internal reflection surface of the light guide 10, and the inclination direction is opposite to the surface 31 of the light coupling device 20. The inclination angle of the surface 31 of the light coupling device 30 is not specifically limited in the present embodiment; it is sufficient to couple light out to the human eye. Furthermore, when the multiple surfaces 31 are arranged within the light guide 10, they are arranged in parallel, meaning that each surface 31 has the same inclination angle relative to the total internal reflection surface.

[0043] When the surface 31 is prepared on the light guide 10, the surface 31 can be embedded in the light guide 10. For example, the surface 31 and the light guide 10 can be fixedly connected by bonding, that is, the light guide 10 is spliced ​​together by multiple components, and the surface 31 is embedded between two components, thereby forming an arrangement of surface 31, component, surface 31, component, ...

[0044] In the specific arrangement, the spacing of the arrangement of multiple surfaces 31 gradually increases along the first direction. Taking the spacing of the five surfaces 31 shown in Figure 3 as an example, d1<d2<d3<d4 is satisfied. In conjunction with the light example shown in Figure 3, the purpose of gradually increasing the arrangement of multiple surfaces 31 is to reduce the surface 31 passing through the adjacent surface 31 when reflecting light, so as to ensure that the energy of the light reflected by each surface 31 is relatively balanced, thereby improving the imaging effect of the optical device. By adjusting the arrangement spacing distance of the surfaces 31, the situation of light passing through the adjacent surfaces 31 in the process of emitting from the light guide 10 is reduced, the effect of the light when emitting is improved, and the use effect of the optical device is thereby improved.

[0045] For ease of understanding, the arrangement of the surfaces 31 provided in the embodiments of the present application is described in detail below. Referring to FIG. 4 , for ease of description, any two adjacent surfaces 31 are taken as an example for illustration. The two surfaces 31 are named as a first surface 311 and a second surface 312, respectively. The first surface 311 is the surface 31 of any adjacent surfaces 31 that is close to the light coupling device 20 along the first direction; the second surface 312 is the surface 31 of any adjacent surfaces 31 that is away from the light coupling device 20 along the first direction.

[0046] Taking the first surface 311 and the second surface 312 shown in FIG4 as an example, the first surface 311 is close to the light coupling device 20, and the second surface 312 is far away from the light coupling device 20. When the first surface 311 and the second surface 312 are specifically arranged, the distance between the first surface 311 and the second surface 312 satisfies the following: along the second direction, the edge light reflected from the end of the second surface 312 away from the light exit surface of the light guide 10 does not pass through the first surface 311 on the way out of the light guide 10, or only passes through the end of the first surface 311 close to the light exit surface of the light guide 10; wherein the second direction is the thickness direction of the light guide 10.

[0047] For ease of description, the end of the first surface 311 closest to the light-emitting surface of the light guide 10 is named Endpoint A, and the end of the second surface 312 farther from the light-emitting surface of the light guide 10 is named Endpoint B. The aforementioned distances are defined as the path (light outcoupling path) where the edge light reflected from Endpoint A passes only through Endpoint B, or does not pass through the first surface 311, on its way out of the light guide 10. When the edge light reflected from the second surface 312 does not pass through Endpoint B or only passes through Endpoint B, light from other angles will certainly not pass through the first surface 311 during reflection. This ensures that the energy of the light coupled out from the second surface 312 is balanced (all are directly coupled out and do not pass through other surfaces 31 on the outcoupling path). Compared to the light outcoupling path in the prior art shown in FIG2 , it can be seen that the optical device provided in the embodiment of the present application, when using surfaces 31 arranged at intervals, can ensure that light reflected from the same surface 31 can propagate to the user's eyes along the same path, thereby ensuring uniform light energy and improving the display effect of the optical device.

[0048] To further understand the arrangement of the aforementioned surfaces 31, the distance between the surfaces 31 gradually increases as they move away from the light coupling device 20. Reference lines are introduced in FIG5 . As shown in FIG5 , endpoint A of each surface 31 is used to construct a reference line along the second longitudinal direction. The four reference lines are L1, L2, L3, and L4. As they move away from the light coupling device 20, the distance between the surfaces 31 changes such that, as they move away from the light coupling device 20, point B on the surface 31 gradually approaches the reference line, then moves to the side of the reference line closer to the light coupling device 20, and then gradually moves away from the reference line. For example, in FIG5 , endpoints B1, B2, B3, and B4 of the surface 31 are arranged in a direction away from the light coupling device. B1 is located to the left of reference line L1, B2 is located to the left of reference line L2, and the distance between B2 and L2 is smaller than the distance between B1 and L1. B3 is located to the right of reference line L3, and B4 is also located to the right of reference line L4. The distance between B3 and L3 is smaller than the distance between B4 and L4. Referring to Figures 3 and 4 , in the arrangement of surfaces 31 using the aforementioned distance variation, edge light reflected from surface 31 can be coupled out without passing through adjacent surfaces 31. This ensures that the energy of light reflected from the same surface 31 is nearly equal, ensuring a pleasant viewing experience for the user.

[0049] As a specific example, the interval H between any two adjacent surfaces 31 satisfies:

[0050] Among them, L is the dimension of surface 31 along the second direction, n is the refractive index of light guide 10; a is the angle between surface 31 and the total internal reflection surface of light guide 10; b is the emission angle of edge light when it passes through the first surface 311 close to the end point of the light output surface of light guide 10; k is the processing error, k is between -0.3mm and +0.3mm.

[0051] The b in the formula can be calculated by the distance between the light guide 10 and the surface 31 and the user's eyes. Specifically, if the distance D1 between the human eye and the light guide 10 is known, and the distance D2 between the edge of the surface 31 and the optical axis of the human eye is known, the light output angle b corresponding to different surfaces 31 is calculated as: arctan(D2 / D1). The calculated b value is then substituted into the above formula. Since a and the refractive index of the light guide 10 are both known data in the formula, the distance between any two adjacent surfaces 31 can be calculated, thereby determining the spacing between each surface 31.

[0052] It should be understood that the processing error k value provided in the embodiment of the present application is the error generated during production and processing, which can be different error values ​​such as -0.3mm, -0.2mm, -0.1mm, 0mm, 0.1mm, 0.2mm, and 0.3mm.

[0053] In the embodiment of the present application, the consideration is that light does not pass through other surfaces 31 when it is reflected from the surface 31 and exits the light guide 10. Furthermore, the consideration is given to the uniformity of light output from the light guide 10, thereby reducing the possibility of light not fully covering the entire light guide 10. Therefore, when arranging the surfaces 31 of the light outcoupling device 30, the spacing between the surfaces 31 is arranged using the arrangement described above, where the edge light passes through the endpoints of adjacent surfaces 31 but does not pass through the surfaces 31.

[0054] In the above embodiment, the spacing arrangement method in which the surfaces 31 extend to the first total internal reflection surface 11 and the second total internal reflection surface 12 is used. That is, the two ends of the surface 31 along the second direction are located at the first total internal reflection surface 11 and the second total internal reflection surface 12, respectively. When the surfaces 31 are arranged in this manner, the spacing between the surfaces 31 satisfies the arrangement rule. When the surfaces 31 do not completely cover the light guide member 10 along the second direction, the multiple surfaces 31 in the light outcoupling device 30 along the second direction are separated from the first total internal reflection surface 11 and the second total internal reflection surface 12 by gaps.

[0055] In a specific example, the gap between the surface 31 and the first total internal reflection surface 11 is equal to the gap between the surface 31 and the second total internal reflection surface 12 .

[0056] The scenario shown in Figure 6 also occurs along the light propagation path. After any light ray passes through the end of surface 31 and propagates to the first total internal reflection surface 11, it then transmits through this surface 31, propagates to the second total internal reflection surface 12, and is reflected again by the second total internal reflection surface 12 to surface 31. When this light ray passes through surface 31 again, if it passes through this surface 31 again, the light ray will be partially reflected by surface 31 (coupling out of the light guide 10), partially transmitted through surface 31, and propagated to the next surface 31. In other words, the same light ray passes through the same surface 31 twice during propagation, thereby reducing the energy of surface 31. For other light rays from the light guide 10, they only pass through the same surface 31 once during propagation. Therefore, when these two light rays are coupled out of the light guide 10, energy imbalance is likely to occur (the light rays that pass through surface 31 twice will lose energy), thereby affecting the display effect.

[0057] To this end, when the optical device provided in the embodiment of the present application is specifically configured, along the second direction, the size of the surface 31 and the size between the first total internal reflection surface 11 and the second total internal reflection surface 12 satisfy:

[0058] Light will be emitted twice consecutively from the same semi-transparent and semi-reflective surface. This situation will also affect the uniformity of light propagation due to the second emission. For example, light passing through surface 31 close to the first total internal reflection surface 11 is reflected by the first total internal reflection surface 11 and transmitted through the surface 31, and then reflected by the second total internal reflection surface 12 to the path of another adjacent surface 31, without being transmitted through surface 31 again. That is, when the light guide 10 and surface 31 are specifically set, the distance between the light guide 10 and surface 31 is sufficient to ensure that the light only passes through the same surface 31 once, so as to ensure that the energy of the light is uniform during propagation (the optical components passed through on the path are consistent).

[0059] In a specific implementation, along the second direction, the vertical distance between the first total internal reflection surface 11 and the second total internal reflection surface 12 is d; the vertical distance between the two ends of the surface 31 is L; then:

[0060] In the above formula, when the surface 31 does not extend to the first total internal reflection surface 11 and the second total internal reflection surface 12 along the second direction, the distance between the surface 31 and the two total internal reflection surfaces of the light guide 10 needs to satisfy the above formula to ensure that the energy of the light is relatively balanced during the propagation process, so as to ensure the final light output effect of the device.

[0061] 6 , it can be seen that when d and L meet the above-mentioned limitations, it is ensured that the light will not pass through surface 31 twice. It should be understood that when there is a gap between surface 31 and the two total internal reflection surfaces of light guide 10, the rules for the gap between the corresponding surfaces 31 can also be applied to the example of the distance between surface 31 and the total internal reflection surface of light guide 10.

[0062] In yet another embodiment, surface 31 may be separated from only one of the total internal reflection surfaces by a gap. For example, one end of surface 31 intersects with first total internal reflection surface 11, while the other end is separated from second total internal reflection surface 12 by a gap. When the above arrangement is adopted, the above-mentioned energy imbalance also occurs when light passing through the end point of surface 31 close to the first total internal reflection surface 11 propagates through the first total internal reflection surface 11 (without being reflected and coupled out by surface 31), propagates to the second total internal reflection surface, and is reflected back to surface 31 by the second total internal reflection surface 12. For this reason, when setting surface 31, the spacing between surface 31 and second total internal reflection surface 12 also satisfies that light only passes through surface 31 once, thereby ensuring uniformity of light during propagation.

[0063] The present application also provides a near-eye display device, comprising a light generator and any of the aforementioned optical devices; wherein light emitted by the light generator is incident upon a light guide 10 of the optical device. In the present application, the light generator is any of an optical collimator, a light source generator assembly, and an image source.

[0064] In the above technical solution, by adjusting the arrangement spacing of the surfaces 31, the situation where light passes through adjacent surfaces 31 during the process of emitting from the light guide 10 is reduced, thereby improving the effect of light when emitting, and further improving the use effect of the optical device.

[0065] The one or more embodiments of this specification are intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of one or more embodiments of this specification shall be included within the scope of protection of this disclosure.

[0066] The above are only specific embodiments of the present application, but the scope of protection of this application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. An optical device, characterized in that: include: A light guide, a light coupling device disposed at one end of the light guide, and a light coupling device disposed at the other end opposite to the light guide; wherein, The light outcoupling device includes a plurality of parallel surfaces, each of which is inclined relative to the total internal reflection surface of the light guide; the plurality of surfaces are spaced apart along the length of the light guide, wherein the spacing between the plurality of surfaces gradually increases along a first direction; the first direction is a direction away from the light incoupling device; Along the first direction, the surface farthest from the light coupling device is a total reflection surface, and the remaining surfaces are partially transmissive and partially reflective sheets.

2. The optical device according to claim 1, wherein Along the first direction, among any adjacent surfaces, the surface close to the light coupling device is the first surface, and the surface farthest from the light coupling device is the second surface; then the distance between the first surface and the second surface satisfies: Along the second direction, the edge light reflected from one end of the second surface away from the light emitting surface of the light guide does not pass through the first surface or only passes through the end point of the first surface close to the light emitting surface of the light guide on the path of exiting the light guide; wherein, the second direction is the thickness direction of the light guide.

3. The optical device according to claim 2, wherein: The interval H between any two adjacent surfaces satisfies: Wherein, L is the dimension of the surface along the second direction, which is the thickness direction of the light guide; n is the refractive index of the light guide; a is the angle between the surface and the total internal reflection surface of the light guide; b is the emission angle of the edge light when it passes through the first surface close to the end point of the light output surface of the light guide; k is the processing error, which is between -0.3 mm and +0.3 mm.

4. The optical device according to claim 3, characterized in that The surface is embedded in the light guide.

5. The optical device according to claim 2, wherein: The total internal reflection surface includes a first total internal reflection surface and a second total internal reflection surface arranged parallel to each other; the light coupled into the light guide member by the light coupling device is totally reflected by the first total internal reflection surface and the second total internal reflection surface to the light coupling device; wherein, Along the second direction, the plurality of surfaces in the light outcoupling device are spaced apart from the first total internal reflection surface and the second total internal reflection surface by gaps.

6. The optical device according to claim 5, characterized in that A gap between the surface and the first total internal reflection surface is equal to a gap between the surface and the second total internal reflection surface.

7. The optical device according to claim 6, characterized in that Along the second direction, the size of the surface and the size between the first total internal reflection surface and the second total internal reflection surface satisfy: The light passing through the surface close to the first total internal reflection surface is reflected by the first total internal reflection surface and transmits through the surface, and then reflected by the second total internal reflection surface to another adjacent surface without transmitting through the surface again.

8. The optical device according to claim 7, wherein: Along the second direction, the vertical distance between the first total internal reflection surface and the second total internal reflection surface is d; the vertical distance between the two ends of the surface is L; then:

9. A near-eye display device, characterized in that: It comprises a light generator and an optical device according to any one of claims 1 to 8; wherein, The light emitted by the light generator is incident on the light guide of the optical device.

10. The near-eye display device according to claim 9, wherein: The light generator is any one of an optical collimator, a light source generator assembly, and an image source.

Images