Cover plate, waveguide module and augmented reality equipment

Abstract

The invention provides a cover plate, a waveguide module and augmented reality equipment. The invention provides a cover plate. The cover plate comprises a substrate layer; the light adjusting film is arranged on one side of the substrate layer in a stacked mode, ambient light comprises first sub-ambient light and second sub-ambient light, the first sub-ambient light and the second sub-ambient light are incident from the same side of the light adjusting film, the first sub-ambient light has a first incident angle, and the second sub-ambient light has a second incident angle. The first sub-ambient light has a first incident angle, the second sub-ambient light has a second incident angle, the first incident angle is smaller than a preset critical angle, the second incident angle is larger than the preset critical angle, and the light transmittance of the first sub-ambient light on the dimming film is larger than that of the second sub-ambient light on the dimming film. When the cover plate is applied to the waveguide module, the rainbow pattern phenomenon of the waveguide module can be effectively improved, and the situation that the normal sight of human eyes is seriously interfered by the rainbow patterns, and visual fatigue is prone to being generated after long-term wearing is better avoided.

Description

Technical Field

[0001] The present application relates to the field of augmented reality technology, and in particular to a cover plate, a waveguide module and an augmented reality device. Background Art

[0002] Augmented reality (AR) technology can combine virtuality with reality and is now being used more and more widely. Optical waveguides are essential components of augmented reality devices. The outcoupling grating of an optical waveguide is used to deflect the light in the optical waveguide at a certain angle so that the light enters the human eye. When ambient light is incident on the outcoupling grating, if the incident angle of the ambient light is higher than a certain critical angle, the diffraction angle after the outcoupling grating is lower than the total reflection angle, and the light will be coupled out and enter the human eye. Since the ambient light is a mixture of light of different colors, and the wavelengths and diffraction angles of different colors are different, when the ambient light is coupled into the human eye through the outcoupling grating, the light of different colors will enter the human eye at different angles, so the human eye will feel linear or halo-shaped color images, i.e., rainbow patterns, which will seriously interfere with the normal vision of the human eye and cause visual fatigue if worn for a long time. Summary of the invention

[0003] In response to the above problems, an embodiment of the present application provides a cover plate, which, when applied to a waveguide module, can effectively improve the rainbow pattern phenomenon of the waveguide module, and better avoid the rainbow pattern from seriously interfering with the normal vision of the human eye, which can easily cause visual fatigue due to long-term wearing.

[0004] In a first aspect, the present application provides a cover plate, comprising:

[0005] basal layer; and

[0006] A dimming film, wherein the dimming film is stacked on one side of the base layer, the ambient light includes a first sub-ambient light and a second sub-ambient light, the first sub-ambient light and the second sub-ambient light are both incident from the same side of the dimming film, the first sub-ambient light has a first incident angle, the second sub-ambient light has a second incident angle, the first incident angle is less than a preset critical angle, the second incident angle is greater than the preset critical angle, and the transmittance of the first sub-ambient light in the dimming film is greater than the transmittance of the second sub-ambient light in the dimming film.

[0007] In a second aspect, the present application provides a waveguide module, comprising:

[0008] an optical waveguide, the optical waveguide being used to transmit an optical signal incident into the optical waveguide; and

[0009] The cover plate described in the first aspect of the present application is stacked and spaced apart from the optical waveguide, so as to protect the optical waveguide.

[0010] In a third aspect, the present application provides an augmented reality device, characterized in that it includes:

[0011] A projection optical machine, the projection optical machine is used to project a light signal, the light signal includes image information;

[0012] The waveguide module according to the second aspect of the present application, wherein the waveguide module is used to transmit the optical signal, and the cover plate is further away from the projection optical machine than the optical waveguide; and

[0013] A processor is electrically connected to the projection optical machine and is used to control the projection optical machine to project the light signal.

[0014] The cover plate of the embodiment of the present application includes a base layer and a dimming film, and the dimming film has different transmittances for ambient light with different incident angles, and the transmittance of the first sub-ambient light with a first incident angle less than a preset critical angle is greater than the transmittance of the second sub-ambient light with a second incident angle greater than the preset critical angle, thereby reducing the transmittance of the second sub-ambient light with a large angle in the ambient light (for example, ambient light with an incident angle greater than the preset critical angle). When applied to a waveguide module, the amount of the second sub-ambient light passing through the cover plate to be incident on the outcoupling grating of the waveguide module can be reduced. In other words, the dimming film can weaken or inhibit the second sub-ambient light from passing through the cover plate to be incident on the outcoupling grating, thereby better improving the rainbow pattern phenomenon caused by ambient light with large incident angles, and better avoiding the rainbow pattern interfering with the normal vision of the human eye, which is prone to visual fatigue when worn for a long time. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0016] Figure 1 This is a light path diagram of ambient light passing through the cover plate and the optical waveguide, and then coupled out by the optical waveguide and entering the human eye.

[0017] Figure 2 It is a schematic structural diagram of a cover plate according to an embodiment of the present application.

[0018] Figure 3 The cover edge of an embodiment of the present application Figure 2 Schematic diagram of the cross-sectional structure in the AA direction.

[0019] Figure 4 The cover edge of another embodiment of the present application Figure 2 Schematic diagram of the cross-sectional structure in the AA direction.

[0020] Figure 5The dimming stack of an embodiment of the present application is Figure 2 Schematic diagram of the cross-sectional structure in the AA direction.

[0021] Figure 6 This is the angular spectrum of light transmittance of the cover plate of Example 1 of the present application.

[0022] Figure 7 This is the angular spectrum of light transmittance of the cover plate of Example 2 of the present application.

[0023] Figure 8 It is a schematic diagram of the top view structure of a waveguide module according to an embodiment of the present application.

[0024] Fig. 9 The waveguide module of one embodiment of the present application is Figure 8 Schematic diagram of the cross-sectional structure in the BB direction.

[0025] Fig.10 1 is a schematic diagram of a top view of the optical waveguide according to an embodiment of the present application.

[0026] Fig.11 FIG. 4 is a schematic diagram of a top view of the optical waveguide according to another embodiment of the present application.

[0027] Fig.12 The waveguide module of another embodiment of the present application is Figure 8 Schematic diagram of the cross-sectional structure in the BB direction.

[0028] Fig.13 It is a schematic diagram of the three-dimensional structure of an augmented reality device according to an embodiment of the present application.

[0029] Fig.14 The augmented reality device of an embodiment of the present application is Fig.13 Schematic diagram of the cross-sectional structure in the CC direction.

[0030] Fig.15 It is a circuit block diagram of an augmented reality device according to an embodiment of the present application.

[0031] Description of reference numerals:

[0032] 100-cover plate, 10-base layer, 30-dimming film, 31-dimming stack, 311-first dimming layer, 313-second dimming layer, 200-waveguide module, 210-optical waveguide, 211-light conduction layer, 212-coupling grating, 213-coupling grating, 214-turning grating, 230-protective layer, 250-first adhesive member, 270-second adhesive member, 300-augmented reality device, 310-projection optical machine, 3101-display, 3103-lens, 320-carrying member, 330-wearing member, 331-first wearable sub-member, 333-second wearable sub-member, 350-processor, 360-memory. DETAILED DESCRIPTION

[0033] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0034] The terms "first", "second", etc. in the specification and claims of this application and the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes steps or units that are not listed, or optionally includes other steps or units inherent to these processes, methods, products or devices.

[0035] The technical solutions in the embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0036] It should be noted that, for the convenience of explanation, in the embodiments of the present application, the same figure marks represent the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments.

[0037] At present, the concept of the metaverse is becoming increasingly popular, and related industries are also beginning to develop rapidly. The metaverse provides an immersive experience based on extended reality technology, generates a mirror image of the real world based on digital twin technology, and builds an economic system based on blockchain technology. It closely integrates the virtual world with the real world in the economic system, social system, and identity system, and allows each user to produce content and edit the world. Among them, extended reality technology (XR) is the foundation of the metaverse, including virtual reality technology (VR), AR, and mixed reality technology (MR).

[0038] Augmented reality is a technology that provides users with enhanced perception of reality by superimposing computer-generated image input onto images in the real world and inputting them into the human eye. It is currently being used more and more widely. Optical waveguides are medium devices that guide light waves to propagate in them and are essential components of augmented reality devices. Optical waveguides can transmit light projected by micro-projectors to the front of the glasses, superimposing a virtual image on the real image in front of the human eye, that is, it has the function of augmented reality. Optical waveguides include geometric optical waveguides (also known as reflective array optical waveguides) and diffraction optical waveguides. Compared with geometric optical waveguides, the gratings of diffraction optical waveguides have higher flexibility in design and production, higher mass production and yield, and are therefore more widely used. For example, the diffraction optical waveguide solution for AR glasses is a mainstream technical solution because its optical lenses are thin and light, and its appearance is closer to traditional glasses. At the same time, the implementation method is more convenient and relatively easy to mass produce. Diffraction optical waveguides can be further divided into surface relief gratings and volume holographic gratings.

[0039] The outcoupling grating of the optical waveguide is used to deflect the light in the optical waveguide to a certain angle so that the light can enter the human eye. Figure 1 , when the ambient light (such as sunlight, lighting, ambient stray light, etc.) Figure 1 When the ambient light is incident on the out-coupling grating 213 of the optical waveguide 210 (as shown by the arrow M), if the incident angle of the ambient light is higher than a certain critical angle, the diffraction angle of the ambient light passing through the out-coupling grating 213 is lower than the total reflection angle, and the ambient light will be coupled out by the out-coupling grating 213 and enter the human eye. Since the ambient light is a mixture of lights of different colors, and the wavelengths of lights of different colors are different, the diffraction angles are different. Therefore, when the ambient light is coupled out by the out-coupling grating 213 and enters the human eye, the lights of different colors will enter the human eye at different angles. Therefore, the wearer will feel a linear or halo-shaped color image, i.e., a rainbow pattern, which will seriously interfere with the normal vision of the human eye. Long-term wearing is prone to visual fatigue and damage to the wearer's eyes. Figure 1 As shown. It can be understood that the outcoupling grating 213 has an effective window. When ambient light is incident on the effective window of the augmented reality device (AR device), when the incident angle is greater than the critical angle, a bright line or bright band will be generated in the effective window of the augmented reality device. This phenomenon is called the rainbow pattern phenomenon. Rainbow patterns cannot be eradicated from the perspective of physical principles. That is, the optical waveguide has an outcoupling grating 213, and there are rainbow patterns caused by the outcoupling grating 213. The rainbow pattern phenomenon will cause the AR display device experience to deteriorate. At present, there is no better way in the industry to eliminate or suppress the diffraction optical waveguide rainbow pattern.

[0040] The "critical angle" in this application refers to the critical angle at which the diffraction angle of the ambient light passing through the out-coupling grating is lower than the total reflection angle of the ambient light in the optical waveguide when the incident angle is higher than the critical angle. That is, the critical angle at which the ambient light incident on the out-coupling grating produces rainbow patterns. The critical angle is related to the total reflection angle of the light in the optical waveguide, the period of the out-coupling grating, and the refractive index of the optical waveguide.

[0041] The improvement or suppression of rainbow patterns can be achieved through the grating design of the optical waveguide, which can suppress the diffraction efficiency of the grating for large-angle incident light (i.e. light with a large incident angle), thereby reducing the rainbow patterns. However, the illumination of outdoor sunlight is usually around 10 4 The unit is lux. To the human eye, reducing the rainbow pattern from tens of thousands of nits to 10,000 or 20,000 nits does not make any essential difference, so the effect of the grating on suppressing the rainbow pattern is very limited.

[0042] See also Figure 2 and Figure 3 The embodiment of the present application provides a cover plate 100, which includes a base layer 10 and a dimming film 30, wherein the dimming film 30 is stacked on one side of the base layer 10, and the ambient light includes a first sub-ambient light and a second sub-ambient light, wherein the first sub-ambient light and the second sub-ambient light are both incident from the same side of the dimming film 30, the first sub-ambient light has a first incident angle, and the second sub-ambient light has a second incident angle, the first incident angle is less than a preset critical angle, and the second incident angle is greater than the preset critical angle, and the transmittance of the first sub-ambient light in the dimming film 30 is greater than the transmittance of the second sub-ambient light in the dimming film 30.

[0043] The cover plate 100 of the embodiment of the present application can be applied to an augmented reality device, used as a protective cover plate 100 for an optical waveguide in a waveguide module of the augmented reality device, and used to improve (or reduce) the rainbow pattern phenomenon of the optical waveguide. When the cover plate 100 is applied to the waveguide module, the cover plate 100 serves as an outer protective cover plate 100 of the waveguide module, that is, the cover plate 100 is farther away from the human eye than the optical waveguide.

[0044] “Ambient light” refers to light incident from outside the cover plate 100 , and the ambient light may be, but is not limited to, visible light such as sunlight, lamplight, and ambient stray light.

[0045] It should be noted that the first sub-ambient light and the second sub-ambient light are incident from the same side of the dimming film 30. The first sub-ambient light and the second sub-ambient light may be incident from the side of the dimming film 30 away from the base layer 10; or the first sub-ambient light and the second sub-ambient light may be incident from the side of the base layer 10 away from the dimming film 30.

[0046] The "preset critical angle" refers to the critical angle at which the light waveguide of the waveguide module generates rainbow patterns when the ambient light passes through the cover plate 100 when the cover plate 100 is applied to the waveguide module. It can also be understood that when the incident angle of the ambient light is higher than the preset critical angle, the diffraction angle of the ambient light passing through the outcoupling grating of the light waveguide is lower than the critical angle of the total reflection angle of the ambient light in the light waveguide.

[0047] Optionally, the preset critical angle may range from 45° to 70°. Further, the preset critical angle may range from 50° to 60°. Specifically, the preset critical angle may be, but is not limited to, 45°, 48°, 50°, 52°, 55°, 58°, 60°, 62°, 65°, 68°, 70°, etc. The preset critical angle is related to the total reflection angle of the light in the optical waveguide, the period of the outcoupling grating, and the refractive index of the optical waveguide.

[0048] In the embodiments of the present application, when a numerical value range from a to b is involved, unless otherwise specified, it means that the numerical value can be any numerical value between a and b, including the endpoint numerical value a and the endpoint numerical value b.

[0049] It can be understood that the first incident angle is smaller than the second incident angle.

[0050] The cover plate 100 of the embodiment of the present application includes a base layer 10 and a dimming film 30, wherein the dimming film 30 has different transmittances for ambient light with different incident angles, and the transmittance of the first sub-ambient light with a first incident angle less than a preset critical angle is greater than the transmittance of the second sub-ambient light with a second incident angle greater than the preset critical angle, thereby reducing the transmittance of the second sub-ambient light with a large angle in the ambient light (for example, ambient light with an incident angle greater than the preset critical angle). When applied to a waveguide module, the amount of the second sub-ambient light passing through the cover plate 100 to be incident on the outcoupling grating of the waveguide module can be reduced. In other words, the dimming film 30 can weaken or inhibit the second sub-ambient light from passing through the cover plate 100 to be incident on the outcoupling grating, thereby better improving the rainbow pattern phenomenon caused by ambient light incident at a large angle, and better avoiding the rainbow pattern interfering with the normal vision of the human eye, which is prone to visual fatigue when worn for a long time.

[0051] Optionally, the base layer 10 is light-transmissive, and the light transmittance of the base layer 10 is greater than or equal to 80%. Further, the light transmittance of the base layer 10 is greater than or equal to 90%. Specifically, the light transmittance of the base layer 10 can be, but is not limited to, 80%, 82%, 85%, 88%, 90%, 92%, 95%, 98%, 99%, etc.

[0052] Optionally, the material of the base layer 10 may be at least one of glass material and resin material. The resin material may be but is not limited to at least one of polyethylene terephthalate (PET for short), polycarbonate (PC for short), and the like.

[0053] Optionally, the thickness of the base layer 10 may be 0.3 mm to 1 mm; specifically, it may be, but not limited to, 0.3 mm, 0.5 mm, 0.8 mm, 1 mm, etc. If the base layer 10 is too thin, it will not provide sufficient protection for the optical waveguide; if the base layer 10 is too thick, the thickness of the waveguide module will be increased, which is not conducive to the thinness of the waveguide module.

[0054] Optionally, the transmittance T1 of the dimming film 30 to the first sub-ambient light is ≥70%, and the transmittance T2 of the dimming film 30 to the second sub-ambient light is ≤30%. It can be understood that the transmittance of the dimming film 30 to the first sub-ambient light can be any value greater than or equal to 70%, and the transmittance of the dimming film 30 to the second sub-ambient light can be any value less than or equal to 30%. Specifically, the transmittance T1 of the dimming film 30 to the first sub-ambient light can be, but not limited to, 70%, 72%, 75%, 78%, 80%, 82%, 85%, 88%, 90%, 92%, 95%, 98%, 99%, etc. The transmittance T2 of the dimming film 30 to the second sub-ambient light may be, but is not limited to, 0%, 2%, 5%, 8%, 10%, 12%, 15%, 18%, 20%, 22%, 25%, 28%, 30%, etc. In this embodiment, the first sub-ambient light with an incident angle less than the preset critical angle has a higher transmittance on the dimming film 30. When the cover plate 100 is applied to the waveguide module, the dimming film 30 can have sufficient transmittance to view the scene or image of the real world through the cover plate 100, without affecting the normal display effect of the waveguide module. In addition, the second sub-ambient light with an incident angle greater than the critical angle has a lower transmittance on the dimming film 30, which can better reduce the proportion of ambient light greater than the preset critical angle incident on the outcoupling grating, thereby better reducing the rainbow pattern phenomenon caused by ambient light greater than the preset critical angle incident on the outcoupling grating, so that the waveguide module using the cover plate 100 has a better display effect.

[0055] Furthermore, the transmittance T1 of the dimming film 30 to the first sub-ambient light is ≥80%, and the transmittance T2 of the dimming film 30 to the second sub-ambient light is ≤20%. In this way, when the cover plate 100 is applied to the waveguide module, it has a higher transmittance for light less than a preset critical angle, so that scenes or images in the real world can be better viewed without affecting the normal display effect of the waveguide module, and has a lower transmittance for ambient light greater than the preset critical angle, so that the generation of rainbow patterns can be better suppressed.

[0056] Furthermore, the transmittance T1 of the dimming film 30 to the first sub-ambient light is ≥85%, and the transmittance 1%≤T2≤20% of the dimming film 30 to the second sub-ambient light is ≤20%.

[0057] Optionally, the reflectivity of the dimming film 30 to the first sub-ambient light is lower than the reflectivity of the dimming film 30 to the second sub-ambient light. In this embodiment, the dimming film 30 has a lower reflectivity to the first sub-ambient light, so that the first sub-ambient light has a higher transmittance. When the cover plate 100 is applied to the waveguide module, the dimming film 30 can have sufficient transmittance to view the scene or image of the real world through the cover plate 100, and will not affect the normal display effect of the waveguide module; the dimming film 30 has a higher reflectivity to the second sub-ambient light, so that the second sub-ambient light has a lower transmittance. When the cover plate 100 is applied to the waveguide module, the rainbow pattern phenomenon generated by the ambient light greater than the preset critical angle incident on the outcoupling grating can be better weakened, so that the waveguide module using the cover plate 100 has a better display effect.

[0058] Optionally, the transmittance of the ambient light in the dimming film 30 decreases as the incident angle increases. The reflectivity of the dimming film 30 to the ambient light increases as the incident angle increases.

[0059] See also Figure 4 and Figure 5 In some embodiments, the dimming film 30 includes at least one dimming stack 31. When the dimming stack 31 is multiple, the multiple dimming stacks 31 are stacked in sequence; each of the dimming stacks 31 includes multiple first dimming layers 311 and multiple second dimming layers 313. The first dimming layers 311 and the second dimming layers 313 are alternately and stacked in sequence. The refractive index of the first dimming layer 311 is anisotropic, and the refractive index of the second dimming layer 313 is isotropic. The term "multiple" means greater than or equal to two.

[0060] In the embodiments of the present application, refractive index anisotropy means that incident light at different angles has different refractions. In other words, anisotropic materials will show different refractive indices in different coordinate directions. Refractive index isotropy means that incident light at different angles has the same refractive index. In other words, the refractive index in each direction shows a single value.

[0061] Optionally, the material of the first dimming layer 311 may be, but is not limited to, at least one of a non-crystalline transparent resin and liquid crystal. The non-crystalline transparent resin may be, but is not limited to, poly(ethylene terephthalateco-1,4-cylclohexylenedimethylene terephthalate, PETG for short).

[0062] Optionally, the material of the second dimming layer 313 may be, but is not limited to, a transparent resin or an oxide. The transparent resin may be, but is not limited to, polyamide (PA for short). The oxide may be, but is not limited to, at least one of silicon oxide, hafnium oxide, aluminum oxide, and the like.

[0063] In this embodiment, the first dimming layer 311 with different refractive indices and the second dimming layer 313 with the same refractive index are alternately stacked in sequence, so that the dimming film 30 has a higher transmittance at a smaller incident angle. When the cover plate 100 is applied to the waveguide module, the dimming film 30 can have sufficient transmittance to view the scenes or images in the real world through the cover plate 100 without affecting the normal display effect of the waveguide module. In addition, the dimming film 30 has a lower transmittance at a larger incident angle, which can better reduce the proportion of ambient light greater than a preset critical angle incident on the outcoupling grating, thereby better reducing the rainbow pattern phenomenon caused by ambient light greater than a preset critical angle incident on the outcoupling grating, so that the waveguide module using the cover plate 100 has a better display effect.

[0064] Optionally, when the incident angle of the ambient light gradually increases, the difference between the refractive index of the first dimming layer 311 and the refractive index of the second dimming layer 313 gradually increases.

[0065] Specifically, in some embodiments, when the incident angle of the ambient light gradually increases, the refractive index of the first dimming layer 311 gradually increases, and the refractive index of the second dimming layer 313 remains unchanged, so that the refractive index difference between the first dimming layer 311 and the second dimming layer 313 gradually increases. In other embodiments, when the incident angle of the ambient light gradually increases, the refractive index of the first dimming layer 311 gradually decreases, and the refractive index of the second dimming layer 313 remains unchanged, so that the refractive index difference between the first dimming layer 311 and the second dimming layer 313 gradually increases.

[0066] Optionally, if the polarization vector of the light in the ambient light is in this plane, it is called p-polarization, and if the polarization vector is perpendicular to the plane, it is called s-polarization. For P-polarized light, the refractive index n of the first dimming layer 311 is A Satisfies the relationship: Among them, θ A is the incident angle of the ambient light, μ y is the magnetic permeability of the first dimming layer 311 in the y direction, μ0 is the vacuum magnetic permeability of the first dimming layer 311, and n x is the refractive index of the first dimming layer 311x, n zis the refractive index of the first dimming layer 311 in the z direction, ε0 refers to the vacuum permittivity of the first dimming layer 311 , the x direction, the y direction and the z direction are perpendicular to each other, and the z direction is the thickness direction of the first dimming layer 311 .

[0067] It can be understood that when the ambient light is incident vertically, that is, the incident angle is 0, the refractive index n of the first dimming layer 311 is A The refractive index n of the second dimming layer 313 B Close, that is, n A ≈n B For the dimming film 30 or the dimming stack 31, which are equivalent to the same material, the transmittance of the dimming film 30 or the dimming stack 31 is very high; when the incident angle of the ambient light increases, the refractive index difference between the first dimming layer 311 and the second dimming layer 313 gradually increases, the proportion of the ambient light incident to the dimming film 30 that is reflected gradually increases, and the transmittance gradually decreases; in other words, when the incident angle of the ambient light increases, the reflectivity of the dimming film 30 to the ambient light increases, and the transmittance decreases, thereby realizing the reflection of the ambient light incident at a large angle, and then realizing the elimination of the rainbow pattern effect of the optical waveguide.

[0068] Optionally, when the incident angle of the ambient light gradually increases, the refractive index n of the first dimming layer 311 A The refractive index n of the second dimming layer 313 is B The range of the difference: 0≤|n A -n B |≤0.3. It can be understood that when the incident angle of the ambient light gradually increases, the refractive index n of the first dimming layer 311 A The refractive index n of the second dimming layer 313 is B The difference gradually increases in any period between 0 and 0.3. For example, it gradually increases from 0 to 0.3; or, it gradually increases from 0.1 to 0.3; or, it gradually increases from 0.05 to 0.2; or, it gradually increases from 0.1 to 0.2, etc.

[0069] In a specific embodiment, when the incident angle of the ambient light gradually increases from 0° to 90°, the refractive index of the first dimming layer 311 gradually increases from 1.5 to 1.7, and the refractive index of the second dimming layer 313 is 1.45 to 1.55.

[0070] In another specific embodiment, when the incident angle of the ambient light gradually increases from 0° to 90°, the refractive index of the first dimming layer 311 gradually increases from 1.6 to 1.4, and the refractive index of the second dimming layer 313 is 1.55 to 1.65.

[0071] Optionally, the thickness d of the dimming film 30 is in the range of 0.1 mm ≤ d ≤ 2 mm. It can be understood that the thickness of the dimming film 30 refers to the thickness of the dimming film 30 along the stacking direction of at least one dimming stack 31. It can also be understood that the thickness of the dimming film 30 refers to the thickness of the dimming film 30 along the stacking direction of the first dimming layer 311 and the second dimming layer 313.

[0072] Specifically, the thickness d of the dimming film 30 may be, but is not limited to, 0.1 mm, 0.15 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.8 mm, 1.0 mm, 1.2 mm, 1.4 mm, 1.6 mm, 1.8 mm, 2.0 mm, etc. If the dimming film 30 is too thin, the suppression effect on the rainbow pattern is limited. If the dimming film 30 is too thick, the light transmittance of the dimming film 30 decreases too obviously. When the cover plate 100 is applied to the waveguide module, the scene or image of the real world viewed by the waveguide module is affected, thereby affecting the display effect of the waveguide module. In addition, the thickness of the waveguide module is increased, which is not conducive to the thinness of the waveguide module. When the thickness of the dimming film 30 is in the range of 0.1 mm to 2 mm, the dimming film 30 can better suppress the rainbow effect, while the transmittance of the dimming film 30 will not be reduced too much as the incident angle increases, so that the waveguide module using the dimming film 30 has a better display effect.

[0073] Furthermore, the thickness d of the dimming film 30 is in the range of 0.2 mm ≤ d ≤ 1 mm. When the thickness of the dimming film 30 is in the range of 0.2 mm to 1 mm, the dimming film 30 can have a better ability to suppress the rainbow effect and have a better display effect at a large angle.

[0074] Optionally, the thickness of each dimming stack 31 ranges from 1 μm to 1000 μm. Specifically, the thickness of each dimming stack 31 may be, but is not limited to, 1 μm, 3 μm, 5 μm, 10 μm, 20 μm, 30 μm, 50 μm, 100 μm, 200 μm, 300 μm, 400 μm, 500 μm, 600 μm, 700 μm, 800 μm, 900 μm, 1000 μm, etc. If the thickness of the dimming stack 31 is too thin, the suppression effect on the rainbow pattern is limited. If the thickness of the dimming stack 31 is too thick, the transmittance of ambient light with a larger incident angle incident on the dimming stack 31 decreases too significantly. When the cover plate 100 is applied to a waveguide module, the display effect of the waveguide module is affected. In addition, the thickness of the waveguide module is increased, which is not conducive to the thinness of the waveguide module. When the thickness of the dimming stack 31 is in the range of 1 μm to 1000 μm, the dimming stack 31 can have a better ability to suppress the rainbow effect, while at the same time, the transmittance of the dimming stack 31 will not be reduced too much as the incident angle increases, thereby making the waveguide module using the dimming stack 31 have a better display effect.

[0075] Furthermore, the thickness of each dimming stack 31 is in the range of 8 μm to 300 μm. When the thickness of the dimming stack 31 is in the range of 8 μm to 300 μm, the dimming stack 31 can have a good effect of suppressing the rainbow effect, and the transmittance of the dimming stack 31 will not be reduced too much with the increase of the incident angle, so that the waveguide module using the dimming stack 31 has a better display effect.

[0076] Optionally, the thicknesses of the plurality of first dimming layers 311 in the same dimming stack 31 are equal, and the thicknesses of the plurality of second dimming layers 313 in the same dimming stack 31 are equal.

[0077] Optionally, the thickness of the first dimming layer 311 and the thickness of the second dimming layer 313 in the same dimming stack 31 may be equal or unequal. Compared with the embodiment in which the thickness of the first dimming layer 311 and the thickness of the second dimming layer 313 are unequal, when the thickness of the first dimming layer 311 and the thickness of the second dimming layer 313 in the same dimming stack 31 are equal, the interference of the ambient light can be better reduced, so that the cover plate 100 has a higher transmittance for the first sub-ambient light with a smaller incident angle, so that the waveguide module using the cover plate 100 has a better display effect.

[0078] Optionally, in the same dimming stack 31, the thickness d1 of the first dimming layer 311 and the thickness d2 of the second dimming layer 313 satisfy: 0≤|d1-d2|≤10nm. Specifically, the thickness d1 of the first dimming layer 311 and the thickness d2 of the second dimming layer 313 can be, but not limited to, 0, 0.5nm, 1nm, 2nm, 3nm, 4nm, 5nm, 6nm, 7nm, 8nm, 9nm, 10nm, etc. The closer the thickness d1 of the first dimming layer 311 is to the thickness d2 of the second dimming layer 313, the smaller the interference of the ambient light after the ambient light is incident, so that the cover plate 100 can have a higher transmittance for the first sub-ambient light with a smaller incident angle, so that the waveguide module using the cover plate 100 has a better display effect. When the thickness difference between the thickness d1 of the first dimming layer 311 and the thickness d2 of the second dimming layer 313 is too large, the interference of ambient light increases, reducing the transmittance of the cover plate 100 to small-angle incident light, which affects the display effect of the waveguide module when applied to the waveguide module.

[0079] Optionally, the thickness d1 of the first dimming layer 311 is in the range of 50nm≤d1≤250nm. Specifically, the thickness d1 of the first dimming layer 311 may be, but is not limited to, 50nm, 60nm, 70nm, 80nm, 90nm, 100nm, 105nm, 110nm, 120nm, 140nm, 160nm, 180nm, 200nm, 220nm, 240nm, 250nm, etc. Too large or too small a thickness of the first dimming layer 311 will reduce the improvement effect of the cover plate 100 on the rainbow pattern of the augmented reality device.

[0080] The thickness d2 of the second dimming layer 313 is in the range of 50nm≤d2≤250nm. Specifically, the thickness d2 of the second dimming layer 313 may be, but is not limited to, 50nm, 60nm, 70nm, 80nm, 90nm, 100nm, 120nm, 140nm, 160nm, 180nm, 200nm, 220nm, 240nm, 250nm, etc. Too large or too small a thickness of the second dimming layer 313 will reduce the improvement effect of the cover plate 100 on the rainbow pattern of the augmented reality device.

[0081] Furthermore, the thickness d1 of the first dimming layer 311 is in the range of 80nm≤d1≤130nm; the thickness d2 of the second dimming layer 313 is in the range of 80nm≤d2≤130nm. When the thickness of the first dimming layer 311 and the second dimming layer 313 are both between 80nm and 130nm, when the cover plate 100 is applied to an augmented reality device, the improvement effect on the rainbow pattern of the augmented reality device is more obvious, and the generation of the rainbow pattern phenomenon can be better suppressed.

[0082] Optionally, when there are multiple dimming stacks 31, any two adjacent dimming stacks 31 satisfy at least one of the following conditions:

[0083] In two adjacent dimming stacks 31 , the thicknesses of the first dimming layers 311 are not equal; and

[0084] In two adjacent dimming stacks 31 , the thicknesses of the second dimming layers 313 are not equal.

[0085] It can be understood that a stack of a first dimming layer 311 and a second dimming layer 313 is defined as a cycle. The number of times the first dimming layer 311 and the second dimming layer 313 alternate is defined as the number of cycles.

[0086] In some embodiments, when there are multiple dimming stacks 31, the thickness of the first dimming layer 311 in any two adjacent dimming stacks 31 is not equal, and the thickness of the second dimming layer 313 is equal. In other embodiments, when there are multiple dimming stacks 31, the thickness of the first dimming layer 311 in any two adjacent dimming stacks 31 is equal, and the thickness of the second dimming layer 313 is not equal. In still other embodiments, when there are multiple dimming stacks 31, the thickness of the first dimming layer 311 in any two adjacent dimming stacks 31 is not equal, and the thickness of the second dimming layer 313 is also different.

[0087] It can be understood that the thicknesses of the first dimming layers 311 in non-adjacent dimming stacks 31 may be the same or different; the thicknesses of the second dimming layers 313 in non-adjacent dimming stacks 31 may be the same or different.

[0088] In this embodiment, compared with the solution with only one dimming stack 31, when the number of dimming stacks 31 is multiple, by adjusting the thickness of the first dimming layer 311 and the second dimming layer 313 in the multiple dimming stacks 31, the transmittance of the second sub-ambient light on the dimming film 30 can be better suppressed. When the cover plate 100 is applied to the waveguide module of the augmented reality device, the generation of rainbow patterns can be better eliminated or suppressed.

[0089] Optionally, the number n of the dimming stacks 31 in the dimming film 30 is in a range of 10≤n≤1000. Specifically, the number n of the dimming stacks 31 in the dimming film 30 may be, but is not limited to, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 180, 200, 250, 300, 400, 500, 600, 700, 800, 900, 1000, etc. If the number of dimming layers 31 in the dimming film 30 is too small, the improvement effect on the rainbow pattern is not obvious when the cover plate 100 is applied to the augmented reality device; when the number of dimming layers 31 in the dimming film 30 is too large, the transmittance of the dimming film 30 is reduced. When it is applied to the augmented reality device, it affects the scene or image effect of the real world viewed by the augmented reality device through the waveguide module.

[0090] Furthermore, the number n of the dimming stacks 31 in the dimming film 30 is in the range of 50≤n≤150. When the number of the dimming stacks 31 is in this range, when the cover plate 100 is applied to an augmented reality device, the rainbow effect of the augmented reality device can be better improved, and the dimming film 30 can have a better light transmittance without affecting the display of scenes or images in the real world.

[0091] Optionally, the range of the period K of the alternating stacking of the first dimming layer 311 and the second dimming layer 313 in each dimming stack 31 is 10≤K≤200. Specifically, the period K of the alternating stacking of the first dimming layer 311 and the second dimming layer 313 in each dimming stack 31 may be, but is not limited to, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 120, 140, 160, 180, 200, etc. If the alternating period between the first dimming layer 311 and the second dimming layer 313 in each dimming stack 31 is too small, the improvement effect on the rainbow pattern of the cover plate 100 when applied to an augmented reality device is not obvious; if the alternating period between the first dimming layer 311 and the second dimming layer 313 in each dimming stack 31 is too large, the transmittance of the dimming film 30 is reduced, and when applied to an augmented reality device, the scene or image effect of the real world viewed by the augmented reality device through the waveguide module is affected.

[0092] Furthermore, the range of the period K of the alternating stacking of the first dimming layer 311 and the second dimming layer 313 in each dimming stack 31 is 50≤K≤100. When the number of the alternating stacking periods of the first dimming layer 311 and the second dimming layer 313 in each dimming stack 31 is within this range, when the cover plate 100 is applied to an augmented reality device, the rainbow effect of the augmented reality device can be better improved, and the dimming film 30 can have a better light transmittance without affecting the display of scenes or images in the real world.

[0093] The cover plate 100 of the present application is further described below through specific embodiments.

[0094] Example 1

[0095] The cover plate 100 of this embodiment includes a base layer 10 and a dimming film 30. The base layer 10 is a transparent glass. The dimming film 30 includes 10 dimming layers 31, that is, n=10. The alternating period of the first dimming layer 311 and the second dimming layer 313 in each dimming layer 31 is 80, that is, K=80. The thickness of the multiple first dimming layers 311 in the same dimming layer 31 is equal, and the thickness of the multiple second dimming layers 313 in each dimming layer 31 is equal. The material of the first dimming layer 311 is polyethylene terephthalate-1,4-cyclohexadiene dimethylene terephthalate, and the material of the second dimming layer 313 is polyamide.

[0096] The thicknesses of the ten dimming stacks 31 are shown in Table 1. Based on the matlab platform, simulation calculations are performed according to the strict coupled wave theory. Under the condition of P deflected light incident, the incident light (i.e., ambient light) with a central wavelength of 513 nm has a transmittance angular spectrum as follows: Figure 6 In this embodiment, when the incident angle of the ambient light gradually increases from 0° to 90°, the refractive index of the first dimming layer 311 for P polarized light gradually decreases from 1.57 to 1.51, and the refractive index of the second dimming layer 313 is 1.57.

[0097] Depend on Figure 6 It can be seen that when the incident angle of the ambient light is less than 58°, the overall transmittance of the cover 100 is relatively high, and the overall transmittance is greater than 83%. When the incident angle of the ambient light is greater than 58°, the transmittance of the cover 100 decreases significantly, indicating that the cover 100 of this embodiment has obvious suppression of incident light at a large angle.

[0098] Table 1 Thickness of the first dimming layer 311 and the second dimming layer 313 in each dimming stack 31 of this embodiment

[0099] Dimming Overlay The first dimming layer Second dimming layer Dimming stack 1 100nm 101nm Dimming stack 2 101nm 102nm Dimming stack 3 102nm 103nm Dimming stack 4 103nm 104nm Dimming stack 5 104nm 105nm Dimming stack 6 105nm 106nm Dimming stack 7 106nm 107nm Dimming stack 8 107nm 108nm Dimming stack 9 108nm 109nm Dimming stack 10 109nm 110nm

[0100] Example 2

[0101] The cover plate 100 of this embodiment includes a base layer 10 and a dimming film 30. The base layer 10 is a transparent glass. The dimming film 30 includes 20 dimming layers 31, that is, n=20. The alternating period of the first dimming layer 311 and the second dimming layer 313 in each dimming layer 31 is 100, that is, K=100. The thickness of the multiple first dimming layers 311 in the same dimming layer 31 is equal, and the thickness of the multiple second dimming layers 313 in each dimming layer 31 is equal. The material of the first dimming layer 311 is polyethylene terephthalate-1,4-cyclohexadiene dimethylene terephthalate, and the material of the second dimming layer 313 is polyamide.

[0102] The thickness of the 20 dimming stacks 31 is shown in Table 2. Based on the matlab platform, simulation calculations are performed according to the strict coupled wave theory. Under the condition of P deflected light incident, the incident light (i.e., ambient light) with a central wavelength of 532nm has a transmittance angular spectrum as follows: Figure 7 In this embodiment, when the incident angle of the ambient light gradually increases from 0° to 90°, the refractive index of the first dimming layer 311 for P polarized light gradually decreases from 1.57 to 1.51, and the refractive index of the second dimming layer 313 is 1.57.

[0103] Depend on Figure 7 It can be seen that when the incident angle of the ambient light is less than 50°, the overall transmittance of the cover 100 is relatively high, and the overall transmittance is greater than 83%. When the incident angle of the ambient light is greater than 50°, the transmittance of the cover 100 decreases significantly, indicating that the cover 100 of this embodiment has obvious suppression of incident light at a large angle.

[0104] In addition, by Figure 6 and Figure 7 It can be known that for ambient light of different wavelengths, when the incident wavelength changes, the transmittance of the cover plate 100 satisfies the requirement that it has a higher transmittance at a smaller incident angle and the transmittance decreases significantly at a larger incident angle.

[0105] Table 2 Thickness of the first dimming layer 311 and the second dimming layer 313 in each dimming stack 31 of this embodiment

[0106] Dimming Overlay The first dimming layer Second dimming layer Dimming stack 1 100nm 101nm Dimming stack 2 101nm 102nm Dimming stack 3 102nm 103nm Dimming stack 4 103nm 104nm Dimming stack 5 104nm 105nm Dimming stack 6 105nm 106nm Dimming stack 7 106nm 107nm Dimming stack 8 107nm 108nm Dimming stack 9 108nm 109nm Dimming stack 10 109nm 110nm Dimming stack 11 110nm 111nm Dimming stack 12 111nm 112nm Dimming stack 13 112nm 113nm Dimming stack 14 113nm 114nm Dimming stack 15 114nm 115nm Dimming stack 16 115nm 116nm Dimming stack 17 116nm 117nm Dimming stack 18 117nm 118nm Dimming stack 19 118nm 119nm Dimming stack 20 119nm 120nm

[0107] See also Figure 8 and Fig. 9 The embodiment of the present application further provides a waveguide module 200, which includes an optical waveguide 210 and the cover plate 100 described in the embodiment of the present application. The optical waveguide 210 is used to transmit the optical signal injected into the optical waveguide 210; the cover plate 100 is stacked and spaced apart from the optical waveguide 210 to protect the optical waveguide 210, so as to improve the drop resistance and scratch resistance of the optical waveguide 210.

[0108] The waveguide module 200 of the embodiment of the present application can be applied to an augmented reality device. The augmented reality device of the embodiment of the present application can be, but is not limited to, a near-eye display system such as augmented reality glasses, an augmented reality helmet, and an augmented reality mask.

[0109] It should be noted that the cover plate 100 in the embodiment of the present application serves as an outer protective layer or outer protective lens of the optical waveguide 210, and the cover plate 100 is farther away from the wearer than the optical waveguide 210. It can also be understood that the ambient light is incident from the side of the cover plate 100 away from the optical waveguide 210.

[0110] Optionally, the dimming film 30 intersects the base layer 10 and is closer to the optical waveguide 210, or the dimming film 30 is farther away from the optical waveguide 210 than the base layer 10. In other words, the dimming film 30 can be disposed on the side of the base layer 10 facing the optical waveguide 210, or can be disposed on the side of the base layer away from the optical waveguide 210. When the dimming film 30 is disposed on the side of the base layer 10 facing the optical waveguide 210, the dimming film 30 can be better prevented from being worn during use, and the service life of the cover plate 100 can be better improved.

[0111] For detailed description of other aspects such as the cover plate 100 and the dimming film 30 , please refer to the description of the corresponding parts of the above embodiments, which will not be repeated here.

[0112] Please also see Fig.10 The optical waveguide 210 further includes a light conducting layer 211, a coupling-in grating 212 and a coupling-out grating 213. The coupling-in grating 212 and the coupling-out grating 213 are arranged at intervals on the surface of the light conducting layer 211 facing the cover plate 100; the coupling-in grating 212 is used to couple the optical signal into the light conducting layer 211; the light conducting layer 211 is used to transmit the optical signal entering the light conducting layer 211; and the coupling-out grating 213 is used to couple the optical signal transmitted through the light conducting layer 211 out of the optical waveguide 210.

[0113] It can be understood that the coupling-in grating 212 can deflect the incident light signal (i.e., light) of the projection optical machine of the augmented reality device by a certain angle using the grating diffraction effect, thereby satisfying the total reflection condition in the light transmission layer 211, so that the light signal is continuously totally reflected in the light transmission layer 211, thereby realizing the transmission of the light signal. When the light signal is transmitted to the coupling-out grating 213, the coupling-out grating 213 again deflects the light signal by a certain angle to couple out the optical waveguide 210, forming an image that enters the wearer's eyes.

[0114] Optionally, the coupling-in grating 212 may be, but not limited to, one of a binary grating, a tilted grating, a blazed grating, a two-dimensional grating, etc. The coupling-out grating 213 may be, but not limited to, one of a binary grating, a tilted grating, a blazed grating, a two-dimensional grating, etc. The coupling-in grating 212 and the coupling-out grating 213 may be of the same type or different types.

[0115] See also Fig.11 In other embodiments, the optical waveguide 210 further includes a turning grating 214, and the turning grating 214 is used to expand the pupil of the image information in the optical signal. The turning grating 214, the coupling-in grating 212, and the coupling-out grating 213 are respectively arranged at intervals on the surface of the optical conductive layer 211 away from the cover plate 100. When the optical waveguide 210 further includes the turning grating 214, the optical signal coupled into the optical conductive layer 211 through the coupling-in grating 212 is firstly expanded through the turning grating 214, and then coupled out of the optical waveguide 210 through the coupling-out grating 213. Optionally, the turning grating 214 can be, but is not limited to, one of a binary grating, a tilted grating, a blazed grating, a two-dimensional grating, etc. The types of the turning grating 214, the coupling-in grating 212, and the coupling-out grating 213 can be the same or different.

[0116] See also Fig.12 In some embodiments, the waveguide module 200 of the embodiment of the present application further includes a protective layer 230, which is stacked and spaced apart on the side of the optical waveguide 210 away from the cover plate 100, for protecting the optical waveguide 210. It can be understood that the cover plate 100, the optical waveguide 210 and the protective layer 230 are stacked and spaced apart in sequence. By providing the protective layer 230, the surface of the optical waveguide 210 facing the wearer can also be protected, which can better prevent the optical waveguide 210 from being scratched, improve the drop resistance of the optical waveguide 210, and increase the life of the waveguide module 200.

[0117] Optionally, the thickness of the protective layer 230 is uniform, and the protective layer 230 cannot change the incident angle of the ambient light incident on the outcoupling grating 213. It can be understood that the surface of the protective layer 230 facing the optical waveguide 210 is parallel to the surface of the protective layer 230 away from the optical waveguide 210.

[0118] Optionally, the protective layer 230 may be translucent or semi-translucent (e.g., ink, brown, gray, etc.). Optionally, the material of the protective layer 230 may be at least one of glass material and resin material. The resin material may be, but is not limited to, at least one of polymethyl methacrylate, polycarbonate, and other resins.

[0119] Optionally, the thickness of the protective layer 230 may be 0.3 mm to 1 mm; specifically, it may be, but not limited to, 0.3 mm, 0.5 mm, 0.8 mm, 1 mm, etc. If the protective layer 230 is too thin, it will not provide sufficient protection for the optical waveguide 210; if the protective layer 230 is too thick, the thickness of the waveguide module 200 will be increased, which is not conducive to the thinness of the waveguide module 200.

[0120] In some embodiments, the waveguide module 200 further includes a first adhesive member 250 and a second adhesive member 270; the first adhesive member 250 is disposed between the optical waveguide 210 and the cover plate 100, and is disposed around the outer periphery of the optical waveguide 210, for bonding the cover plate 100 to the optical waveguide 210, and spacing the optical waveguide 210 and the cover plate 100, so that an air gap exists between the optical waveguide 210 and the cover plate 100; the second adhesive member 270 is disposed between the optical waveguide 210 and the protective layer 230, and is disposed around the outer periphery of the optical waveguide 210, for bonding the protective layer 230 to the optical waveguide 210, and spacing the optical waveguide 210 and the protective layer 230.

[0121] Optionally, the first adhesive member 250 and the second adhesive member 270 are both middle frame structures or ring structures. Optionally, the first adhesive member 250 can be, but not limited to, a plastic frame, optical adhesive (i.e., OCA adhesive), etc.; the second adhesive member 270 can be, but not limited to, a plastic frame, optical adhesive (i.e., OCA adhesive), etc. In other embodiments, the first adhesive member 250 and the second adhesive member 270 can also be polymer micro-pillars arranged at intervals.

[0122] See also Figures 13 to 15 The embodiment of the present application further provides an augmented reality device 300, which includes a projection optical machine 310, a waveguide module 200 of the above embodiment of the present application, and a processor 350. The projection optical machine 310 is used to project a light signal, and the light signal includes image information; the waveguide module 200 is used to transmit the light signal, and the cover plate 100 is farther away from the projection optical machine than the light waveguide 210; the processor 350 is electrically connected to the projection optical machine 310, and is used to control the projection optical machine 310 to project the light signal, thereby displaying image information.

[0123] The augmented reality device 300 of the embodiment of the present application may be, but is not limited to, a near-eye display system such as augmented reality glasses, an augmented reality helmet, an augmented reality mask, etc. In the drawings of the present application, the augmented reality device 300 is illustrated by taking augmented reality glasses as an example, which should not be understood as a limitation on the augmented reality device 300 of the present application, nor should it be understood as a limitation on the waveguide module 200 of the present application.

[0124] For a detailed description of the waveguide module 200 , please refer to the description of the corresponding part of the above embodiment, which will not be repeated here.

[0125] Optionally, the projection optical machine 310 includes a display 3101 and a lens 3103. The display 3101 is electrically connected to the processor 350, and is used to emit a light signal with image information under the control of the processor 350; the lens 3103 is arranged on the display surface side of the display 3101, and is used to modulate the light signal, so that the light (light signal) of different viewing angles emitted from the same pixel point on the display 3101 is modulated by the lens 3103 and emitted in the form of parallel light, so that the image information in the light signal is at an infinite position so that it can be seen by the naked eye. The waveguide module 200 is arranged on the side of the lens 3103 away from the display 3101, and is used to transmit the light signal modulated by the lens 3103.

[0126] In one embodiment, the coupling-in grating 212 and the coupling-out grating 213 of the optical waveguide 210 are disposed away from the projection optical engine 310. In another embodiment, the coupling-in grating 212 and the coupling-out grating 213 of the optical waveguide 210 are disposed toward the projection optical engine 310.

[0127] In some embodiments, the waveguide module 200 can also dilate the image information in the optical signal emitted by the lens 3103 in one dimension or two dimensions to increase the range of the eye orbit, thereby accommodating more people.

[0128] Optionally, the processor 350 includes one or more general-purpose processors, wherein the general-purpose processor can be any type of device capable of processing electronic instructions, including a central processing unit (CPU), a microprocessor, a microcontroller, a main processor, a controller, and an ASIC, etc. The processor 350 is used to execute various types of digital storage instructions, such as software or firmware programs stored in a memory, which enables the computing device to provide a wide variety of services.

[0129] Optionally, the augmented reality device 300 of the embodiment of the present application further includes a memory 360. The memory 360 is electrically connected to the processor 350 and is used to store program codes required for the processor 350 to run, program codes required for controlling the display 3101, image information emitted by the display 3101, and the like.

[0130] Optionally, the memory 360 may include a volatile memory (Volatile Memory), such as a random access memory (Random Access Memory, RAM); the memory 360 may also include a non-volatile memory (NVM), such as a read-only memory (Read-Only Memory, ROM), a flash memory (Flash Memory, FM), a hard disk drive (Hard Disk Drive, HDD) or a solid-state drive (SSD). The memory 360 may also include a combination of the above-mentioned types of memory.

[0131] In some embodiments, the augmented reality device 300 further includes a carrier 320 for carrying the waveguide module 200 , and the optical waveguide 210 , the cover plate 100 , and the protective layer 230 are assembled into one body with the carrier 320 .

[0132] Optionally, the carrier 320 may be, but is not limited to, a frame of augmented reality glasses, a helmet body of an augmented reality helmet, a mask body of an augmented reality mask, etc. Optionally, the waveguide module 200 may be disposed on the carrier 320 by an adhesive or a fastening portion.

[0133] In some embodiments, when the augmented reality device 300 is an augmented reality glasses, the augmented reality device 300 of the embodiment of the present application further includes a wearing member 330. The wearing member 330 is rotatably connected to the bearing member 320, and the wearing member 330 is used to clamp the wearer (such as a human head, or a head prosthesis, etc.).

[0134] Optionally, the wearing component 330 includes a first wearing component 331 and a second wearing component 333, wherein the first wearing component 331 is rotatably connected to one end of the supporting component 320, and the second wearing component 333 is rotatably connected to the other end of the supporting component 320 away from the first wearing component 331. The first wearing component 331 cooperates with the second wearing component 333 to clamp the augmented reality device 300 to the wearer. Optionally, the first wearing component 331 and the second wearing component 333 are also used to set the projection light machine 310. Optionally, the first wearing component 331 and the second wearing component 333 can be, but are not limited to, the temples of the augmented reality device 300 (AR glasses).

[0135] Mentioning "embodiment" and "implementation method" in this application means that the specific features, structures or characteristics described in conjunction with the embodiment may be included in at least one embodiment of the present application. The appearance of the phrases in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described in this application can be combined with other embodiments. In addition, it should also be understood that the features, structures or characteristics described in the various embodiments of the present application can be arbitrarily combined to form another embodiment that does not deviate from the spirit and scope of the technical solution of the present application, provided that there is no contradiction between them.

[0136] Finally, it should be noted that the above implementation modes are only used to illustrate the technical solution of the present application and are not intended to limit it. Although the present application has been described in detail with reference to the above preferred implementation modes, a person of ordinary skill in the art should understand that the technical solution of the present application may be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present application.

Claims

1. A cover plate, characterized in that: include: basal layer; as well as A dimming film, wherein the dimming film is stacked on one side of the base layer, the ambient light includes a first sub-ambient light and a second sub-ambient light, the first sub-ambient light and the second sub-ambient light are both incident from the same side of the dimming film, the first sub-ambient light has a first incident angle, the second sub-ambient light has a second incident angle, the first incident angle is less than a preset critical angle, the second incident angle is greater than the preset critical angle, and the transmittance of the first sub-ambient light in the dimming film is greater than the transmittance of the second sub-ambient light in the dimming film.

2. The cover plate according to claim 1, characterized in that: The transmittance T1 of the dimming film to the first sub-ambient light is ≥70%, and the transmittance T2 of the dimming film to the second sub-ambient light is ≤30%.

3. The cover plate according to claim 1, characterized in that: The reflectivity of the dimming film to the first sub-ambient light is lower than the reflectivity of the dimming film to the second sub-ambient light.

4. The cover plate according to any one of claims 1 to 3, characterized in that: The dimming film includes at least one dimming stack. When the number of the dimming stack is multiple, the multiple dimming stacks are stacked in sequence; each of the dimming stacks includes multiple first dimming layers and multiple second dimming layers, the first dimming layers and the second dimming layers are alternately and stacked in sequence, the refractive index of the first dimming layer is anisotropic, and the refractive index of the second dimming layer is isotropic.

5. The cover plate according to claim 4, characterized in that: When the incident angle of the ambient light gradually increases, the difference between the refractive index of the first dimming layer and the refractive index of the second dimming layer gradually increases.

6. The cover plate according to claim 4, characterized in that: The thicknesses of the multiple first dimming layers in the same dimming stack are equal, and the thicknesses of the multiple second dimming layers in the same dimming stack are equal.

7. The cover plate according to claim 4, characterized in that: When there are multiple dimming stacks, any two adjacent dimming stacks meet at least one of the following conditions: In two adjacent dimming stacks, the thicknesses of the first dimming layers are not equal; as well as In two adjacent dimming stacks, the thicknesses of the second dimming layers are not equal.

8. The cover plate according to claim 4, characterized in that: The number n of the dimming stacks in the dimming film is in a range of 10≤n≤1000; the period K of the alternating stacking of the first dimming layer and the second dimming layer in each dimming stack is in a range of 10≤K≤200.

9. The cover plate according to claim 4, characterized in that: The range of the thickness d1 of the first dimming layer is: 50nm≤d1≤250nm; the range of the thickness d2 of the second dimming layer is: 50nm≤d2≤250nm.

10. A waveguide module, characterized in that: include: An optical waveguide, the optical waveguide being used to transmit an optical signal incident into the optical waveguide; as well as The cover plate according to any one of claims 1 to 9, wherein the cover plate and the optical waveguide are stacked and spaced apart to protect the optical waveguide.

11. An augmented reality device, characterized in that: include: A projection optical machine, the projection optical machine is used to project a light signal, the light signal includes image information; The waveguide module of claim 10, wherein the waveguide module is used to transmit the optical signal, and the cover plate is further away from the projection optical machine than the optical waveguide; as well as A processor is electrically connected to the projection optical machine and is used to control the projection optical machine to project the light signal.

Images