Optical waveguide device and near-eye display device

Abstract

The present invention relates to an optical waveguide device and a near-eye display device, the optical waveguide device comprising: a waveguide substrate having a first surface and a second surface parallel to each other, an array of diaphragms, and a plurality of diaphragms obliquely arranged between the first surface and the second surface; a grating plate and a sawtooth plate respectively arranged on the first surface or the second surface, with the sawtooth plate being arranged opposite to the grating plate, the sawtooth plate at least comprising a sawtooth reflective surface, the sawtooth reflective surface comprising a plurality of first saw teeth connected in sequence end to end, the first saw teeth at least comprising an inclined reflective surface, and the inclination direction of the inclined reflective surface being the same as the inclination direction of the array of diaphragms; all or part of an incident light beam is transmitted by total reflection between the grating plate and the sawtooth plate, and compared with total reflection transmission only within the waveguide substrate, the direction of the reflected light beam that undergoes total reflection is rotated clockwise by an angle of γ, effectively reducing process difficulty, thereby reducing ghosting, improving light uniformity, and enhancing imaging quality.

Description

Technical Field

[0001] The present invention relates to the field of augmented reality technology, and in particular to an optical waveguide device and a near-eye display device. Background Art

[0002] Waveguide solutions for augmented reality display technology typically include arrayed waveguides and diffraction waveguides. Arrayed waveguides are primarily derived using geometric optics. They utilize a coated optical surface to create a semi-transparent, semi-reflective effect that influences the optical path, achieving pupil expansion and in- and out-coupling. Diffraction waveguides utilize the diffraction effect of light, using gratings to deflect light as needed, similarly achieving in- and out-coupling and pupil expansion.

[0003] Compared with the two, the advantage of arrayed waveguides is that traditional coatings have a wide response to wavelengths or angles, while diffraction waveguides cannot effectively guarantee a wider wavelength range and angle range, that is, a large field of view, due to physical and process limitations. The advantage of diffraction waveguides is that the pupil continuity is better, and there are no film layer splicing gaps in arrayed waveguides. At the same time, the physical and process limitations that may exist in the design and coating process of film layers with different polarizations do not exist in the design of diffraction systems.

[0004] The outcoupling structure of the current traditional array waveguide is based on Figure 1 Light propagates between the upper and lower surfaces of the waveguide substrate 10'. The same beam of light entering the film from two different angles of incidence, α and β: at a low angle α, the reflected light is coupled out, while the transmitted light continues onward. At a high angle β, the transmitted light continues onward, while the reflected light forms a ghost image, or ghost light M. The coating design for the arrayed waveguide aims to minimize reflectivity for high-angle incidence, i.e., β-incidence. However, due to physical and process limitations, it is difficult to achieve a very low reflectivity for high-angle incidence in actual coatings. Summary of the Invention

[0005] In view of the problems existing in the prior art, the present invention provides an optical waveguide device and a near-eye display apparatus.

[0006] The technical solutions of the present invention are as follows:

[0007] This specification provides an optical waveguide device, comprising:

[0008] The waveguide substrate comprises at least an outcoupling region, wherein the waveguide substrate located in the outcoupling region has a first surface and a second surface parallel to each other, and a plurality of arrayed beam splitting films arranged in parallel and spaced apart from each other are provided between the first surface and the second surface, and the plurality of beam splitting films are arranged obliquely;

[0009] a grating plate, the grating plate being arranged on the first surface or the second surface;

[0010] a sawtooth plate, the sawtooth plate being disposed on the second surface or the first surface and being disposed opposite the grating plate, the sawtooth plate including at least one side of the surface away from the waveguide substrate having a sawtooth reflective surface, the sawtooth reflective surface including a plurality of first saw teeth connected in sequence end to end, the first saw teeth including at least an inclined reflective surface, and the inclined direction of the inclined reflective surface being the same as the inclined direction of the beam splitter film;

[0011] All or part of the incident light beam is totally reflected and transmitted between the grating plate and the sawtooth plate. Compared with the case where all or part of the incident light beam is totally reflected and transmitted only in the waveguide substrate, the direction of the reflected light beam is rotated and offset by an angle γ in the clockwise direction.

[0012] As a preferred technical solution, for the monochromatic light of the incident light beam incident on the surface of the grating plate, the grating equation is:

[0013] d[sinθ+sin(θ-γ)]=nλ

[0014] Among them, the incident angle of the incident light entering the grating plate is θ, the diffraction angle of the grating plate is θ-γ, the scale spacing of the grating is d, and d is the grating constant, the wavelength of the incident light beam is λ, and n is the diffraction order.

[0015] As a preferred technical solution, each first saw tooth is a right-angled triangle saw tooth.

[0016] As a preferred technical solution, the serrated plate also includes a horizontal plane arranged opposite to the serrated reflective surface, and the horizontal plane is parallel to the first surface or the second surface, wherein the horizontal plane is arranged on the second surface or the first surface, and the angle between the horizontal plane and the inclined reflective surface is equal to γ / 2.

[0017] As a preferred technical solution, the first sawtooth period D and the first sawtooth height H of the sawtooth reflective surface satisfy the following relationship:

[0018]

[0019] As a preferred technical solution, the first sawtooth period D satisfies the following relationship:

[0020]

[0021] Among them, the maximum height of the first sawtooth is H max .

[0022] As a preferred technical solution, the waveguide substrate, the grating plate and the sawtooth plate are an integrally formed structure.

[0023] As an optimal technical solution, it also includes a serrated compensation plate, one side of which is provided with a plurality of second serrations connected end to end, the plurality of second serrations are complementary to the plurality of first serrations and are arranged correspondingly, and a gap is provided between the serrated compensation plate and the serrated plate.

[0024] As a preferred technical solution, it also includes a wedge-shaped compensation plate, and the inclined surface of the wedge-shaped compensation plate is arranged close to the side of the sawtooth reflection surface.

[0025] This specification also provides a near-eye display device, including the above-mentioned optical waveguide device.

[0026] The beneficial effects achieved by the technical solution adopted by the present invention are:

[0027] This specification provides an optical waveguide device and a near-eye display device. By arranging a grating plate on one surface of a traditional waveguide substrate and a sawtooth plate on the other surface, the deflection effect of light on the grating or sawtooth is utilized, and the reflected light emitted by total reflection is deflected clockwise by an angle γ. That is, compared with the large-angle β incident angle of the traditional array film, the γ angle is reduced, which effectively reduces the difficulty of coating a high-transmittance film, thereby reducing ghost images and improving the uniformity of light. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments, which constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are provided to explain the present invention and do not constitute an undue limitation of the present invention. In the drawings:

[0029] Figure 1 A schematic diagram of light propagation in an optical waveguide device in the prior art;

[0030] Figure 2 Schematic diagram of the structure of the optical waveguide device disclosed in Examples 1 and 2;

[0031] Figure 3 Schematic diagram of the structure of the optical waveguide device disclosed in Examples 1 and 2;

[0032] Figure 4 Schematic diagram of the structure of the optical waveguide device disclosed in Examples 1 and 2;

[0033] Figure 5 Schematic diagram of the structure of the optical waveguide device disclosed in Examples 1 and 2.

[0034] Description of reference numerals:

[0035] Waveguide substrate 10 ; grating plate 20 ; sawtooth plate 30 ; sawtooth compensation plate 40 ; wedge-shaped compensation plate 50 . DETAILED DESCRIPTION

[0036] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with specific embodiments of the present invention and corresponding drawings. In the description of the present invention, it should be noted that the term "or" is generally used in the sense of including "and / or" unless the content clearly indicates otherwise.

[0037] In the description of the present invention, it should be understood that the terms "first", "second", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance. In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through a medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0038] In addition, those skilled in the art should understand that, in the disclosure of the present invention, the terms "longitudinal", "transverse", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like to indicate orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the above terms cannot be understood as limiting the present invention.

[0039] Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0040] Example 1

[0041] according to Figure 2 and Figure 3 , an embodiment of the present invention provides an optical waveguide device, comprising:

[0042] The waveguide substrate 10 includes at least an outcoupling region. The waveguide substrate 10 located in the outcoupling region has a first surface and a second surface that are parallel to each other. A plurality of arrayed beam splitting films are provided between the first surface and the second surface. The plurality of beam splitting films are arranged in an inclined manner.

[0043] The grating plate 20 is disposed on the first surface or the second surface;

[0044] A sawtooth plate 30 is disposed on the second surface or the first surface and is disposed opposite the grating plate 20. The sawtooth plate 30 includes at least one side of the surface away from the waveguide substrate 10 having a sawtooth reflective surface. The sawtooth reflective surface includes a plurality of first saw teeth connected in sequence end to end. The first saw teeth include at least an inclined reflective surface, and the inclined direction of the inclined reflective surface is the same as the inclined direction of the beam splitter film.

[0045] All or part of the incident light beam is totally reflected and transmitted between the grating plate 20 and the serrated plate 30. Compared with the case where all or part of the incident light beam is totally reflected and transmitted only within the optical waveguide substrate 10, the direction of the totally reflected all or part of the light beam is rotated and offset by an angle γ in the clockwise direction.

[0046] In this embodiment, the offset γ angle can be obtained by combining Figure 1 To understand the traditional technical solution given, when light is transmitted in the waveguide plate of the traditional existing solution, that is, it is transmitted by total reflection only in the waveguide substrate 10, and the same beam of light will have different incident angles α and β when incident from two directions of the film layer: when the incident angle is small α, the reflected light is coupled out and the transmitted light continues to be transmitted; when the incident angle is large β from the other side, the transmitted light continues to be transmitted, and the reflected light becomes a ghost image, that is, ghost light M. In order to eliminate the ghost phenomenon, a grating plate 20 and a sawtooth plate 30 are respectively arranged on both sides of the waveguide substrate 10, that is, the light beam is transmitted by total reflection between the grating plate 20 and the sawtooth plate 30, so that when the light beam is incident on the grating plate 20 or the sawtooth plate 30 through the array spectrometer film, the direction of the reflected light that is totally reflected is reduced by the angle γ compared with the incident angle of the traditional array film with large angle β.

[0047] In view of the ghost phenomenon caused by the out-coupling structure of the existing array waveguide and the problem that the reflectivity at large angles of incidence is difficult to control due to physical and process limitations, in this embodiment, a grating plate 20 is provided on one surface of the traditional waveguide plate and a sawtooth plate 30 is provided on the other surface, that is, the light is totally reflected and transmitted between the grating plate 20 and the sawtooth plate 30. By utilizing the deflection effect of the light passing through the grating plate 20 or the sawtooth plate 30, the reflected light emitted by the total reflection is deflected by an angle γ in a clockwise direction, that is, the incident angle γ is reduced compared to the large-angle β incident angle of the traditional array film, thereby effectively reducing the difficulty of coating a high-transmittance film, thereby reducing the ghost phenomenon and improving the uniformity of the light.

[0048] Preferably, for the monochromatic light of the incident light beam incident on the surface of the grating plate 20, the grating equation is:

[0049] d[sinθ+sin(θ-γ)]=nλ;

[0050] The incident angle of the incident light entering the grating plate 20 is θ, the diffraction angle of the grating plate 20 is θ-γ, the scale spacing of the grating is d, and d is the grating constant. The wavelength of the incident light beam is λ, and n is the diffraction order.

[0051] Specifically, the waveguide substrate 10 includes a first surface and a second surface, and a plurality of arrayed spectroscopic films are arranged at intervals and in parallel between the first surface and the second surface, and the plurality of spectroscopic films are all inclined in the same direction, wherein the first surface and the second surface are parallel or approximately parallel, and the plurality of spectroscopic films can be arranged at equal intervals or at unequal intervals, or some of the plurality of spectroscopic films can be arranged at equal intervals and the other portion can be arranged at unequal intervals, etc., as well as the specific values ​​of the spacing between adjacent spectroscopic films. It is up to actual needs to select which setting method and specific values ​​to use, and these can also be set by those skilled in the art according to actual needs.

[0052] according to Figure 2 , a grating plate 20 is set on the first surface, a sawtooth plate 30 is set on the second surface, and the multiple pieces of splitter films are not parallel to the first surface and the second surface, so that when the light incident on the waveguide substrate 10 is directed to the array splitter film, the array splitter film couples part of the incident light out from the sawtooth plate 30 set on the surface of the waveguide substrate 10 to the human eye. In another embodiment, according to Figure 3 A serrated plate 30 is provided on the first surface, and a grating plate 20 is provided on the second surface. When the light in the waveguide substrate 10 is emitted toward the array spectrometer, the array spectrometer couples part of the light out from the grating plate 20 provided on the surface of the waveguide substrate 10 to emit toward the human eye.

[0053] A grating plate 20 is set on the first surface and a serrated plate 30 is set on the second surface, or a serrated plate 30 is set on the first surface and a grating plate 20 is set on the second surface. The structures of the two are exactly the same, the difference is that the direction is rotated 180° to achieve coupling from the serrated plate 30 side and coupling from the grating plate 20 side respectively.

[0054] The combination of the grating plate 20, the waveguide substrate 10 and the serrated plate 30 is preferably fixed by gluing or bonding, wherein the waveguide substrate 10 and the serrated plate 30 are preferably made of the same material, such as glass or transparent resin, to ensure stable transmission of light and help the waveguide achieve better display effects and imaging quality.

[0055] Furthermore, assume that light of different wavelengths and incident angles (θ1, λ1) and (θ2, λ2) are diffraction angles of φ1 and φ2. Since the grating plate 20 is used in conjunction with the serrated plate 30, the deflection of light by the serrated plate 30 complies with the law of reflection. The reflection angle of all light is equal to the incident angle, so the diffraction angle φ1 = φ2, that is, the deflection angle γ is a constant. Therefore, the grating equation is:

[0056] d[sinθ+sin(θ-γ)]=nλ;

[0057] The incident angle of the incident light entering the grating plate 20 is θ, the diffraction angle of the grating plate 20 is (θ-γ), the scale spacing of the grating is d, and d is the grating constant. The wavelength of the incident light beam is λ, and n is the diffraction order.

[0058] Furthermore, when γ is a constant, it is obvious that the value of d will be different for different (θ, λ). Therefore, in actual use, different grating parameters can be set on the same grating, for example, by using methods similar to multiple exposures in volume holographic gratings.

[0059] The source of the incident light beam can be the monochromatic light emitted by the optical machine, or other methods are possible. The incident light emitted by the optical machine passes through a coupling element, and the coupling element can be a coupling prism to couple the incident light into the waveguide matrix. The light is then transmitted by total reflection between the grating plate 20 and the serrated plate 30. When the light is transmitted to the array spectrometer film in the waveguide matrix, part of the light is reflected by the spectrometer film and emitted from the grating plate 20 or the serrated plate 30 to enter the human eye, and the other part of the light is transmitted by the spectrometer film and will continue to be transmitted forward.

[0060] In one embodiment, according to Figure 2 Because the grating plate 20 is disposed on the first surface of the waveguide substrate 10 and the sawtooth plate 30 is disposed on the second surface, transmitted light can pass through the first surface of the waveguide substrate 10 and enter the grating plate 20. After reflection and deflection by the grating plate 20, the total internal reflection of the reflected light is rotated clockwise by an angle γ compared to traditional total internal reflection. In other words, compared to traditional methods, the incident angle β of the incident light entering from the other end of the dichroic film becomes β, and β' = β - γ. In this case, the incident angle of the high-angle incident light on the array dichroic film is reduced by γ, effectively reducing the difficulty of coating a high-transmittance film, thereby reducing ghost images and improving light uniformity. Due to the tilted dichroic film and the grating deflection effect, the light deflected by an angle γ passes through the same dichroic film twice.

[0061] That is to say, when the light is incident on the spectroscopic film at a small angle α for the first transmission, part of the light will be emitted from the waveguide substrate 10 and the serrated plate 30 and enter the human eye, and the transmitted light will be incident on the same spectroscopic film again at a deflected angle β' on the other side of the spectroscopic film for a second transmission. The transmitted light is incident on the second surface of the waveguide substrate 10 and enters the serrated plate 30. After being reflected by the serrated plate 30, the light is incident on the same spectroscopic film again. On this basis, part of the light is reflected and emitted from the waveguide substrate 10 and the serrated plate 30, and then enters the human eye. Another part of the light is transmitted for a third time, and the transmitted light is incident on the next spectroscopic film and continues to be transmitted in the waveguide matrix.

[0062] In another embodiment, according to Figure 3 A serrated plate 30 is provided on the first surface of the waveguide substrate 10, and a grating plate 20 is provided on the second surface. The transmitted light can be transmitted through the first surface of the waveguide substrate 10 into the serrated plate 30. The serrated plate 30 includes a serrated reflective surface. The serrated reflective surface has a plurality of first serrations connected in sequence end to end. The first serrations include an inclined reflective surface. Light is reflected when incident on the inclined reflective surface. The inclined reflective surface of the first serration can also be understood as the thickness of the first serration gradually decreases from left to right.

[0063] The light is totally reflected and transmitted between the sawtooth plate 30 and the grating plate 20. When the light is incident on the dichroic film at a small angle α for the first time, part of the light will be emitted from the waveguide substrate 10 to the grating plate 20 in sequence until it enters the human eye, and the transmitted light will be incident on the same dichroic film again on the other side of the dichroic film at the same deflected incident angle β' for the second time. In other words, the sawtooth reflective surface of the sawtooth plate 30 plays the same deflection and reflection role, achieving a better effect than the traditional method in which the light is only incident on the waveguide substrate 1. 0 is transmitted by total internal reflection, and the reflected light of total reflection rotates clockwise by an angle of γ, and then the transmitted light is incident on the second surface of the waveguide substrate 10 and enters the grating plate 20. After being reflected by the grating plate 20, the light is incident on the same dichroic film again. On this basis, part of the light is reflected and emitted from the waveguide substrate 10 and the grating plate 20, that is, the light is coupled out from the grating plate 20 and incident on the human eye, and the other part of the light is transmitted for the third time, and the transmitted light is incident on the next dichroic film and continues to be transmitted in the waveguide matrix. Regardless of which of the above methods is used, the principle of light deflection in the grating plate 20 or the serrated plate 30 is used to achieve total internal reflection of the reflected light with a smaller angle of γ than the traditional method, solving the problem of difficult to control low reflectivity at large angles of incidence, reducing process difficulty, effectively reducing ghosting, improving light uniformity, and further improving product quality.

[0064] Preferably, each first saw tooth is a right-angled triangle saw tooth.

[0065] Preferably, the serrated plate 30 further includes a horizontal plane arranged opposite to the serrated reflective surface, and the horizontal plane is parallel to the first surface or the second surface, wherein the horizontal plane is arranged on the second surface or the first surface, and the angle between the horizontal plane and the inclined reflective surface is equal to γ / 2.

[0066] Preferably, the first sawtooth period D and the first sawtooth height H of the sawtooth reflective surface satisfy the following relationship:

[0067]

[0068] Preferably, the first sawtooth period D satisfies the following relationship:

[0069]

[0070] Among them, the maximum height of the first sawtooth is H max .

[0071] Specifically, according to Figure 2-Figure 3 The sawtooth plate 30 mentioned above has a first sawtooth that at least includes an inclined reflective surface, wherein the inclination direction of the inclined reflective surface is the same as the inclination direction of the beam splitter film. From the perspective of process manufacturing, the sawtooth plate 30 can be understood as setting one side of the flat plate to be sawtooth-shaped, specifically, a plurality of first sawtooths connected in sequence at the end; the sawtooth plate 30 also includes a horizontal plane and a side surface, the horizontal plane is set on the first surface or the second surface of the waveguide substrate 10, and the side surface is located on the left side of the inclined reflective surface. The angle between the horizontal plane and the inclined reflective surface is γ / 2. The shapes and sizes of the plurality of first sawtooths are the same or different and can be selected according to actual needs.

[0072] Furthermore, the sawtooth plate 30, viewed as a whole, has a plurality of identical first saw teeth, each of which is preferably a right triangle. The angle between the horizontal plane and the inclined reflective surface is γ / 2. The horizontal plane is perpendicular to the side surface, and a small gap can exist between the horizontal plane and the inclined reflective surface to ensure the overall continuity of the sawtooth plate 30 and to greatly reduce or even completely eliminate ghosting. Adjacent first saw teeth can be directly connected, or there can be the same gap between adjacent first saw teeth, where the gap is much smaller than the length of the inclined reflective surface. For example, the lowest point of the inclined reflective surface of a first saw tooth is directly connected to the lowest point of the side surface of the next first saw tooth, and there is a gap between the inclined reflective surface of a first saw tooth and the lowest point of the side surface of the next first saw tooth, and the two are connected via the two ends of the gap.

[0073] For the first sawtooth, there is the following relationship between its sawtooth period D and sawtooth height H:

[0074]

[0075] At the same time, the first sawtooth period D satisfies the following relationship:

[0076]

[0077] Among them, the maximum height of the first sawtooth is H max Since the γ angle is a constant, the γ / 2 angle in the above two equations can be the angle between the horizontal plane and the inclined reflecting surface, or it can be the direction of the reflected light that is totally reflected when all or part of the incident light beam passes through the array spectrometer and enters the grating plate 20 or the serrated plate 30, and is offset clockwise by half of the γ angle, that is, the γ / 2 angle.

[0078] Preferably, the waveguide substrate 10 , the grating plate 20 and the sawtooth plate 30 are an integrally formed structure.

[0079] Preferably, a sawtooth compensation plate 40 is further included, and a plurality of second sawteeth connected end to end are provided on one side of the sawtooth compensation plate 40, and the plurality of second sawteeth are complementary to the plurality of first sawteeth and are arranged correspondingly.

[0080] Specifically, a grating plate 20 is disposed on the first surface of the waveguide substrate 10, and a sawtooth plate 30 is disposed on the second surface; alternatively, the sawtooth plate 30 is disposed on the first surface and the grating plate 20 is disposed on the second surface. The two structures are identical, but rotated 180°. In actual processing, they can be bonded together to form an integrated structure, preferably using transparent optical glue, which can achieve stable light transmission and low manufacturing cost. Alternatively, they can be bonded together to form an integrated structure, effectively improving light transmission efficiency and light uniformity. Of course, other methods can also be used to achieve an integrated structure, which is not specifically limited here. For greater clarity, the waveguide substrate 10, the grating plate 20, and the sawtooth plate 30 are integrated and referred to as a waveguide plate.

[0081] Strictly speaking, the outgoing light perpendicular to the horizontal waveguide will have a certain deflection angle when coupled out on the inclined surface. This angle is equal to Where n is the refractive index of the waveguide. If you want to eliminate this deflection, you can set compensation on the two surfaces of the waveguide to Figure 3 For example, a sawtooth compensation plate 40 having a structure complementary to the sawtooth plate 30 is used, that is, one side of the sawtooth compensation plate 40 is provided with a plurality of second saw teeth connected end to end, and the plurality of second saw teeth are complementary to the plurality of first saw teeth and are arranged correspondingly, see Figure 4 Complementarity means that the first sawtooth and the second sawtooth can directly engage with each other, so that the sawtooth plate 30 and the sawtooth compensation plate 40 can be seamlessly spliced, which helps to eliminate the above-mentioned deflection phenomenon, improve the display imaging quality, and further enhance the visual experience of the human eye.

[0082] For the film layer design of the arrayed waveguide in this embodiment, the grating plate 20 combined with the sawtooth plate 30 is set up, which can easily achieve the control of the reflection law at a small angle α to about 10%, and the reflectivity at a large angle β to be as low as possible, that is, below 0.5%. This helps to reduce the incident angle and reduce the difficulty of coating design and manufacturing, making it easier to control it below 0.5%, that is, reduce the process difficulty, and easily achieve low reflectivity at a large angle β. The present structure is simple and can be widely used.

[0083] Example 2

[0084] This embodiment provides an optical waveguide device, which differs from the first embodiment in that the shape of the compensation plate is different.

[0085] Preferably, a wedge-shaped compensation plate 50 is further included, with the inclined surface of the wedge-shaped compensation plate 50 being disposed adjacent to the sawtooth reflective surface. Similarly, in order to eliminate the problem mentioned in the first embodiment that the outgoing light perpendicular to the horizontal waveguide is deflected at a certain angle when coupled out on the inclined surface, if the angle γ / 2 is very small, a whole wedge-shaped compensation plate 50 can also be used for compensation. Figure 5 The wedge-shaped compensation plate 50 can be a right triangle, with its oblique surface facing close to the sawtooth reflective surface. The wedge-shaped compensation can also be a right trapezoid, with its oblique waist facing close to the sawtooth reflective surface, which helps to eliminate the deflection angle, is simpler to manufacture, can reduce processing difficulty, and improve light transmission efficiency.

[0086] Example 3

[0087] This embodiment also provides a near-eye display device, including the above-mentioned optical waveguide device, which effectively reduces the difficulty of coating a high-transmittance film, thereby reducing ghost images, improving the uniformity of light, and effectively improving product quality.

[0088] The above is a detailed introduction to an optical waveguide device and a near-eye display device according to an embodiment of the present application. Specific examples are used herein to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method and core idea of ​​the present application. At the same time, for those skilled in the art, according to the idea of ​​the present application, there may be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present application.

Claims

1. An optical waveguide device, characterized in that: include: A waveguide substrate comprising at least an outcoupling region, wherein the waveguide substrate located in the outcoupling region has a first surface and a second surface parallel to each other, and a plurality of arrayed beam splitter films spaced apart and arranged in parallel are provided between the first surface and the second surface, and the plurality of beam splitter films are arranged obliquely; a grating plate, the grating plate being arranged on the first surface or the second surface; a sawtooth plate, the sawtooth plate being disposed on the second surface or the first surface and being disposed opposite the grating plate, the sawtooth plate comprising at least a sawtooth reflective surface, the waveguide substrate being disposed on a side away from the sawtooth reflective surface, the sawtooth reflective surface comprising a plurality of first sawteeth sequentially connected end to end, the first sawteeth comprising at least an inclined reflective surface, and the inclined direction of the inclined reflective surface being the same as the inclined direction of the beam splitter film; The incident light beam is transmitted by total reflection between the grating plate and the serrated plate, wherein the spectroscopic film can split the incident light beam into a reflected light beam and a transmitted light beam. The reflected light beam is emitted from the waveguide substrate, and the transmitted light beam, after being reflected by the grating plate or the serrated plate, is rotated clockwise by an angle of γ and then passes through the spectroscopic film again.

2. The optical waveguide device according to claim 1, wherein For the monochromatic light of the incident light beam incident on the surface of the grating plate, the grating equation is: d[sinθ+sin(θ-γ)]=nλ The incident angle of the incident light beam entering the grating plate is θ, the diffraction angle of the grating plate is θ-γ, the scale spacing of the grating is d, and d is the grating constant. The wavelength of the incident light beam is λ, and n is the diffraction order.

3. The optical waveguide device according to claim 1, wherein Each of the first saw teeth is a right-angled triangle saw tooth.

4. The optical waveguide device according to claim 3, wherein The serrated plate also includes a horizontal plane arranged opposite to the serrated reflective surface, and the horizontal plane is parallel to the first surface or the second surface, wherein the horizontal plane is arranged on the second surface or the first surface, and the angle between the horizontal plane and the inclined reflective surface is equal to γ / 2.

5. The optical waveguide device according to claim 4, wherein The first sawtooth period D and the first sawtooth height H of the sawtooth reflective surface satisfy the following relationship:

6. The optical waveguide device according to claim 5, wherein The first sawtooth period D satisfies the following relationship: The maximum height of the first sawtooth is Hmax.

7. The optical waveguide device according to claim 1, wherein The waveguide substrate, the grating plate and the sawtooth plate are an integrally formed structure.

8. The optical waveguide device according to any one of claims 1 to 7, characterized in that: It also includes a sawtooth compensation plate, one side of which is provided with a plurality of second sawteeth connected end to end, and the plurality of second sawteeth are complementary to the plurality of first sawteeth and are arranged correspondingly.

9. The optical waveguide device according to any one of claims 1 to 7, characterized in that: It also includes a wedge-shaped compensation plate, wherein the inclined surface of the wedge-shaped compensation plate is arranged adjacent to one side of the sawtooth reflective surface.

10. A near-eye display device, characterized in that: The optical waveguide device comprises the optical waveguide device according to any one of claims 1 to 9.

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