CN116755253A - Optical waveguide, display assembly and AR equipment - Google Patents
Optical waveguide, display assembly and AR equipment Download PDFInfo
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- CN116755253A CN116755253A CN202310684953.3A CN202310684953A CN116755253A CN 116755253 A CN116755253 A CN 116755253A CN 202310684953 A CN202310684953 A CN 202310684953A CN 116755253 A CN116755253 A CN 116755253A
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- 230000003287 optical effect Effects 0.000 title claims abstract description 111
- 239000000758 substrate Substances 0.000 claims abstract description 136
- 210000001747 pupil Anatomy 0.000 claims description 17
- 239000010410 layer Substances 0.000 description 35
- 230000008878 coupling Effects 0.000 description 8
- 238000010168 coupling process Methods 0.000 description 8
- 238000005859 coupling reaction Methods 0.000 description 8
- 238000010586 diagram Methods 0.000 description 8
- 230000003190 augmentative effect Effects 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 3
- 230000000644 propagated effect Effects 0.000 description 3
- 230000000694 effects Effects 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000004424 eye movement Effects 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000002356 single layer Substances 0.000 description 1
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
- G02B27/01—Head-up displays
- G02B27/017—Head mounted
- G02B27/0172—Head mounted characterised by optical features
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/0001—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
- G02B6/0011—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form
- G02B6/0013—Means for improving the coupling-in of light from the light source into the light guide
- G02B6/0023—Means for improving the coupling-in of light from the light source into the light guide provided by one optical element, or plurality thereof, placed between the light guide and the light source, or around the light source
- G02B6/0026—Wavelength selective element, sheet or layer, e.g. filter or grating
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/0001—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
- G02B6/0011—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form
- G02B6/0033—Means for improving the coupling-out of light from the light guide
- G02B6/005—Means for improving the coupling-out of light from the light guide provided by one optical element, or plurality thereof, placed on the light output side of the light guide
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- Optical Couplings Of Light Guides (AREA)
Abstract
The application discloses an optical waveguide, a display assembly and AR equipment, which relate to the technical field of optical display, and comprise at least two layers of waveguide substrates, wherein each waveguide substrate is provided with a coupling-in area and a coupling-out area, the orthographic projections of the coupling-in areas of two adjacent waveguide substrates are staggered, the coupling-in areas of at least two layers of waveguide substrates are used for corresponding sub-beams with different angles in full-view field light emitted by a light machine, so that the sub-beams with the corresponding angles are coupled in and are coupled out from the coupling-out areas after being subjected to at least one total reflection in the waveguide substrates, and a preset area is covered at a target distance, wherein the propagation distance of the sub-beams entering the waveguide substrates from the coupling-in areas on the surface of the waveguide is larger than the propagation distance of the coupling-in areas along the propagation direction of the sub-beams. The optical waveguide, the display component and the AR equipment provided by the application solve the problem of energy loss caused by secondary diffraction of the coupling-in area in the prior art, and improve the display efficiency and uniformity of the optical waveguide.
Description
Technical Field
The application relates to the technical field of optical display, in particular to an optical waveguide, a display assembly and AR equipment.
Background
Augmented reality (Augmented Reality, AR) technology is a technology that smartly merges virtual information with the real world, and such a head-mounted display using the augmented reality technology allows people to view the surrounding environment while projecting virtual images to the eyes of the people. Among them, the diffractive optical waveguide is a display scheme of the mainstream AR device, and many AR devices adopt such a display scheme, and since the diffractive optical waveguide has the advantages of light weight, large viewing angle, large eye movement range, and low mass production cost, it is generally considered as a mainstream display technical route in the AR industry.
The diffractive optical waveguide requires a coupling-in and coupling-out process if the light beam from the light engine is to be directed into the human eye. The light beam emitted by the optical machine is coupled into the optical waveguide through the coupling-in area, is totally reflected and transmitted in the coupling-in area, and finally is emitted from the exit pupil area to enter the human eye. When the thickness of the optical waveguide is thinner, as shown in fig. 2, the optical path distance of the primary total reflection of a part of light beams coupled into the optical waveguide through the coupling-in area is smaller than the size of the entrance pupil grating, as shown by the light beams represented by the broken line in fig. 2, the part of light beams are again incident into the coupling-in area to carry out secondary diffraction, the part of light beams can increase energy emitted out of the optical waveguide along with the secondary diffraction, the energy entering the optical waveguide is reduced, and finally, the brightness of an image formed by the light beams coupled out of the coupling-out area is uneven, so that the display effect is affected; when the thickness of the optical waveguide is thicker and the size of the coupling-in region is larger, as shown in fig. 3, the distance travelled by the light beam on the surface of the optical waveguide is larger due to the primary total reflection, so that the pupils copied and coupled out by the coupling-out region are not overlapped, resulting in discontinuous images and poor color uniformity of the picture.
Disclosure of Invention
The application aims to provide an optical waveguide, a display component and an AR device, which solve the problem of energy loss caused by secondary diffraction of a coupling-in area in the prior art, so that the application can reduce secondary diffraction on the basis of a thinner optical waveguide, increase the energy of a light beam entering the optical waveguide, and further improve the display efficiency and uniformity of the optical waveguide.
In one aspect, an embodiment of the present application provides an optical waveguide, including at least two layers of waveguide substrates, where each waveguide substrate has a coupling-in area and a coupling-out area, orthographic projections of the coupling-in areas of two adjacent waveguide substrates are offset from each other, and the coupling-in areas of at least two layers of waveguide substrates are used for corresponding sub-beams with different angles of view in total-view light emitted by an optical bench, so that the sub-beams with corresponding angles of view are coupled in and are coupled out from the coupling-out area after being totally reflected at least once in the waveguide substrate, and a preset area is covered at a target distance, where a distance of propagation of the sub-beams entering the waveguide substrate from the coupling-in area on a surface of the waveguide substrate through one total reflection is greater than a distance of the coupling-in area along a propagation direction of the sub-beams.
As an embodiment, the coupling-in region and the coupling-out region of the waveguide substrate are each provided with a grating, the gratings of the coupling-in regions of different waveguide substrates having different duty cycles and/or different depths and/or different inclination angles.
As an embodiment, the dimensions of the coupling-out regions of the waveguide substrates are all the same, and the orthographic projections of the coupling-out regions of two adjacent waveguide substrates overlap each other.
As an implementation manner, the sizes of the coupling-out regions of the waveguide substrates are different, and the front projections of the coupling-out regions of two adjacent waveguide substrates are arranged in a staggered manner.
As an implementation manner, at least two layers of waveguide substrates are connected by a frame, and a gap is formed between two adjacent layers of waveguide substrates, wherein the gap is smaller than 0.1mm.
As one embodiment, the refractive index of the waveguide substrate is 1.5-2.5 and the thickness is less than 1mm.
In another aspect, an embodiment of the present application provides a display assembly, including an optical engine and the optical waveguide disposed on an optical-engine light-emitting side, where full-field light emitted from the optical engine is divided into a plurality of sub-beams corresponding to the waveguide substrate at different angles of view, and the plurality of sub-beams are respectively coupled into the corresponding waveguide substrate by a coupling-in area and propagated in the waveguide substrate.
As an embodiment, the projection of the sub-beams onto the corresponding waveguide substrate falls within the range of the corresponding coupling-in region.
As an implementation manner, the dimension of the projection of the full-field light onto the waveguide substrate farthest from the optical machine along the width direction is Ln, the dimension of the shadow formed by projection splicing of the plurality of coupling-in areas on the surface of the optical waveguide along the width direction is L1, the dimension of the exit pupil plane of the full-field light along the width direction is L2, and Ln, L1 and L2 satisfy the relation Ln > L1> L2, wherein the width direction is the total reflection propagation direction of the sub-beams in the waveguide substrate.
In another aspect, an embodiment of the present application provides an AR device, including an optical engine and the optical waveguide disposed on an optical output side of the optical engine, or including the display assembly, where full-field light emitted from the optical engine is transmitted through the optical waveguide and then emitted, and received by a human eye in a preset area at a target distance.
The beneficial effects of the embodiment of the application include:
the application provides an optical waveguide, which comprises at least two layers of waveguide substrates, wherein each waveguide substrate is provided with a coupling-in area for coupling in light beams and a coupling-out area for coupling out light beams, orthographic projections of the coupling-in areas of two adjacent waveguide substrates are staggered, the coupling-in areas of at least two layers of waveguide substrates are used for corresponding sub-light beams with different angles in full-view light emitted by an optical machine, so that the sub-light beams with corresponding angles are coupled in and are coupled out from the coupling-out area after being subjected to at least one total reflection in the waveguide substrate, and a preset area is covered at a target distance, wherein the propagation distance of the sub-light beams entering the waveguide substrate from the coupling-in area on the surface of the waveguide substrate is larger than the propagation distance of the coupling-in area along the sub-light beam propagation direction through one total reflection. According to the application, the full-view field light emitted by the optical machine is incident into different coupling-in areas according to different view angles, and the coupling-in areas correspond to the view angles of the sub-beams, and the propagation distance of the sub-beams entering the waveguide substrate from the coupling-in areas on the surface of the waveguide substrate through primary total reflection is larger than the propagation distance of the coupling-in areas along the sub-beam propagation direction, so that the secondary diffraction of the light beams in the coupling-in areas in the prior art is avoided, the energy loss caused by the secondary diffraction in the coupling-in areas is avoided, the energy of the light beams entering the optical waveguide is further increased, the display efficiency and uniformity of the optical waveguide are improved, and the problem of the energy loss caused by the secondary diffraction in the coupling-in areas of thinner optical waveguides in the prior art is solved.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments will be briefly described below, it being understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered as limiting the scope, and other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
FIG. 1 is a schematic diagram of the optical path of an optical waveguide in the prior art;
FIG. 2 is a schematic diagram of the optical path of a thinner optical waveguide of the prior art;
FIG. 3 is a schematic diagram of the optical path of a thicker optical waveguide of the prior art;
FIG. 4 is a schematic diagram of an optical waveguide according to an embodiment of the present application;
FIG. 5 is a second schematic diagram of an optical waveguide according to an embodiment of the present application;
FIG. 6 is a schematic diagram of an optical waveguide according to an embodiment of the present application;
FIG. 7 is a schematic diagram of a display assembly according to an embodiment of the present application;
fig. 8 is a schematic structural diagram of a display assembly according to an embodiment of the present application.
Icon: 10-an optical waveguide; 11-a waveguide substrate; 12-a coupling-in region; 13-a coupling-out region; 20-a display assembly; 21-ray machine.
Detailed Description
For the purpose of making the objects, technical solutions and advantages of the embodiments of the present application more apparent, the technical solutions of the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application, and it is apparent that the described embodiments are some embodiments of the present application, but not all embodiments of the present application. The components of the embodiments of the present application generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.
Thus, the following detailed description of the embodiments of the application, as presented in the figures, is not intended to limit the scope of the application, as claimed, but is merely representative of selected embodiments of the application. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.
It should be noted that: like reference numerals and letters denote like items in the following figures, and thus once an item is defined in one figure, no further definition or explanation thereof is necessary in the following figures.
In the description of the present application, it should be noted that, directions or positional relationships indicated by terms such as "center", "vertical", "horizontal", "inner", "outer", etc., are directions or positional relationships based on those shown in the drawings, or those that are conventionally put in place when the product of this application is used, are merely for convenience of describing the present application and simplifying the description, and are not indicative or implying that the apparatus or element to be referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be construed as limiting the present application.
In the description of the present application, it should also be noted that, unless explicitly specified and limited otherwise, the terms "disposed," "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; may be a mechanical connection. The specific meaning of the above terms in the present application will be understood in specific cases by those of ordinary skill in the art.
As shown in fig. 1 and 2, in the single-layer optical waveguide with a smaller thickness in the prior art, the size of the entrance pupil grating must be greater than or equal to the exit pupil plane of the optical engine, so that the entrance pupil grating can receive all the light beams emitted by the optical engine. When the thickness of the optical waveguide is smaller and the size of the entrance pupil grating is larger, the optical waveguide emits light beams with a certain field angle, the edge blue light b1 and the edge red light r1 enter the entrance pupil grating in the same period, the first-order diffraction light angle of the edge blue light b1 is smaller than that of the edge red light r1, the edge blue light b1 is used as the light beam with the farthest incidence direction relative to the exit pupil grating and the shortest wavelength in all the light beams emitted by the optical waveguide, the angle of the first-order diffraction light beam entering the optical waveguide is minimum, and the primary total reflection optical path (the distance of primary total reflection on the surface of the optical waveguide) in the optical waveguide is shortest. When the optical path of the first total reflection of the edge blue light b1 after being diffracted by the entrance pupil grating is smaller than the size of the entrance pupil grating, the light beam can be shot to the entrance pupil grating again to cause a second diffraction light beam b3, and the light beam b3 can exit out of the optical waveguide, so that the energy loss of the blue light is caused, and the light efficiency of the display image light of the exit pupil grating is reduced and the uniformity of the picture color is deteriorated.
The application provides an optical waveguide 10, as shown in fig. 4, 5 and 6, comprising at least two layers of waveguide substrates 11, wherein each waveguide substrate 11 is provided with a coupling-in area 12 for coupling in light beams and a coupling-out area 13 for coupling out light beams, the orthographic projections of the coupling-in areas 12 of two adjacent waveguide substrates 11 are staggered, the coupling-in areas 12 of at least two layers of waveguide substrates 11 are used for corresponding sub-light beams with different angles of view in the full-view light emitted by an optical machine 21, so that the sub-light beams with corresponding angles of view are coupled in and are coupled out from the coupling-out area 13 after being subjected to at least one total reflection in the waveguide substrates 11, and a preset area is covered at a target distance, wherein the distance of the sub-light beams entering the waveguide substrates 11 from the coupling-in area 12, which are propagated on the surface of the waveguide substrates 11 through one total reflection, is larger than the distance of the coupling-in the sub-light beam propagation direction of the coupling-in area 12.
The full-view light emitted from the optical machine 21 is divided into a plurality of sub-beams with different view angles, each sub-beam is respectively incident into the coupling-in area 12 of the corresponding waveguide substrate 11, is coupled into the waveguide substrate 11 through the coupling-in area 12, undergoes at least one total reflection in the waveguide substrate 11, and is finally coupled out by the corresponding coupling-out area 13, and the sub-beams coupled out by all the coupling-out areas 13 are spliced at a certain distance to display a complete image light picture. According to the embodiment of the application, different coupling-in areas 12 are correspondingly arranged on the multi-layer waveguide substrate 11 for sub-beams with different angles of view, so that the sub-beams with different angles of view enter different waveguide substrates 11, the size of the coupling-in areas 12 on each layer of waveguide substrate 11 is reduced, and secondary diffraction of the beams in the coupling-in areas 12 is avoided, so that energy loss caused by secondary diffraction is avoided, energy of the beams entering the optical waveguide 10 is further increased, and display efficiency and uniformity of the optical waveguide 10 are improved.
Specifically, taking the example that the sub-beam of the nth view angle enters the nth layer waveguide substrate 11 as shown in fig. 7, the outer edge beam of the nth view angle (far from the coupling-out region 13) passes through the coupling-in region 12 of the nth layer waveguide substrate 11 and enters the first total reflection optical path distance Sn of the diffracted light in the nth layer waveguide substrate 11, where the first total reflection optical path distance refers to the distance that the sub-beam propagates on the surface of the waveguide substrate 11 through the first total reflection. The size of the coupling-in region 12 on the nth layer waveguide substrate 11 along the total reflection propagation direction of the sub-beams is Cn, the size of the coupling-in region 12 along the total reflection propagation direction of the sub-beams is smaller than the first total reflection optical path distance Sn, that is Cn < Sn, all sub-beams entering the waveguide substrate 11 from the coupling-in region 12 are projected to the total reflection surface of the non-coupling-in region of the waveguide substrate 11 after one total reflection, so that the marginal beam entering the nth layer waveguide substrate 11 at the nth field angle is not projected to the coupling-in region 12 again to form secondary diffraction.
Wherein, the shortest-wavelength edge beam does not re-project to the coupling-in region 12, so that all the beams do not re-project to the coupling-in region 12, because the first-order diffraction angle of the shortest-wavelength beam is minimum, the distance that the shortest-wavelength beam travels on the surface of the waveguide substrate 11 through the first total reflection is shortest.
The sub-beams entering the waveguide substrate 11 from the coupling-in region 12 are totally projected to the total reflection surface of the non-coupling-in region of the waveguide substrate 11 after one-time total reflection, so that all the sub-beams are not projected to the coupling-in region 12 again, thereby avoiding secondary diffraction of the sub-beams in the coupling-in region 12, avoiding energy loss caused by secondary diffraction, further increasing the energy of the beam entering the optical waveguide 10, and improving the display efficiency and uniformity of the optical waveguide 10.
It will be appreciated that when a sub-beam of a certain field angle is incident on the coupling-in region 12 on the n+1-th layer waveguide substrate 11, it can directly penetrate the n-th layer waveguide substrate 11 and then be coupled into the n+1-th layer waveguide substrate 11 by the coupling-in region 12 on the n+1-th layer waveguide substrate 11, as shown in fig. 8. Of course, the same applies to the coupling-out region 13, and the sub-beam coupled out by the coupling-out region 13 on the n+1 layer waveguide substrate 11 directly passes through the first n layer waveguide substrate 11 and is directed to the target distance. In addition, in the embodiment of the present application, different coupling-in areas 12 are set for different angles of view in the full-view light emitted from the same optical engine 21, so the light entrance surfaces of the coupling-in areas 12 should all face the optical engine 21, that is, the directions of the light entrance surfaces of the coupling-in areas 12 are consistent.
In addition, the number of layers of the waveguide substrate 11 is not limited in the embodiment of the present application, and those skilled in the art may set the number according to actual situations. As long as the coupling-in area 12 is identical in number to the sub-beams and is capable of coupling into sub-beams at all angles of view.
The optical waveguide 10 provided by the application comprises at least two layers of waveguide substrates 11, wherein each waveguide substrate 11 is provided with a coupling-in area 12 for coupling in light beams and a coupling-out area 13 for coupling out light beams, the orthographic projections of the coupling-in areas 12 of two adjacent waveguide substrates 11 are staggered, the coupling-in areas 12 of at least two layers of waveguide substrates 11 are used for corresponding sub-light beams with different angles of view in the full-view light emitted by the optical machine 21, so that the sub-light beams with corresponding angles of view are coupled in and are coupled out from the coupling-out area 13 after being subjected to at least one total reflection in the waveguide substrates 11, and a preset area is covered at a target distance, wherein the distance of the sub-light beams entering the waveguide substrates 11 from the coupling-in area 12, which are propagated on the surface of the waveguide substrates 11, is larger than the distance of the coupling-in the direction of the sub-light beams from the coupling-in area 12 after one total reflection. The application makes the full-view field light emitted by the optical machine 21 incident into the corresponding coupling-in area 12 according to different view angles, and as the coupling-in area 12 corresponds to the view angle of the sub-beams, the propagation distance of the sub-beams entering the waveguide substrate 11 from the coupling-in area 12 on the surface of the waveguide substrate through primary total reflection is larger than the propagation distance of the coupling-in area 12 along the sub-beams, the secondary diffraction of the beams in the coupling-in area 12 in the prior art is avoided, thereby avoiding the energy loss caused by the secondary diffraction in the coupling-in area, further increasing the energy of the beams entering the optical waveguide 10, and improving the display efficiency and uniformity of the optical waveguide 10. The problem of energy loss caused by secondary diffraction of a coupling-in area of a thinner optical waveguide in the prior art is solved.
Optionally, as shown in fig. 4, the coupling-in region 12 and the coupling-out region 13 of the waveguide substrate 11 are each provided with a grating, the duty cycle and/or the depth and/or the inclination angle of the gratings of the coupling-in regions 12 of different waveguide substrates 11 are different.
The duty ratio, depth and inclination angle of the gratings of the coupling-in areas 12 on different waveguide substrates 11 are set differently, so that the first-order diffraction efficiency of the sub-beams with different angles of view is higher and the diffraction efficiency of each grating is not greatly different.
Specifically, at least one parameter of the duty ratio, the depth and the inclination angle is different, and the person skilled in the art specifically sets the parameters according to the actual situation.
In addition, since the full field light emitted from the same optical engine 21 into which a plurality of gratings are coupled contains light beams of the same wavelength, the grating period and the grating direction of the gratings in the coupling region 12 of the different waveguide substrates 11 should be the same.
In one implementation manner of the embodiment of the present application, as shown in fig. 4, 5 and 6, the dimensions of the coupling-out regions 13 of the waveguide substrates 11 are the same, and the orthographic projections of the coupling-out regions 13 of two adjacent waveguide substrates 11 overlap each other.
The coupling-out regions 13 of the waveguide substrates 11 are arranged uniformly, so that the positions of the coupling-out regions 13 on each layer of waveguide substrates 11 are the same, and thus, in the processing process of the optical waveguide 10, the positions of the coupling-out regions 13 on each layer of waveguide substrates 11 are the same, and the processing of the coupling-out regions 13 is relatively convenient.
Alternatively, as shown in fig. 8, the dimensions of the coupling-out regions 13 of the waveguide substrates 11 are different, and the front projections of the coupling-out regions 13 of two adjacent waveguide substrates 11 are offset.
As can be seen from the foregoing, the sub-beams coupled out of the coupling-out region 13 on the n+1 layer waveguide substrate 11 directly penetrate the n front layer waveguide substrate 11, and are directed to the target distance, the sizes of the coupling-out regions 13 of the waveguide substrates 11 are set differently, and the front projections of the coupling-out regions 13 of two adjacent waveguide substrates 11 are set in a staggered manner, so that the number of times of projecting the sub-beams coupled out of the coupling-out region 13 of the n+1 layer waveguide substrate 11 to the coupling-out region 13 of the n front layer waveguide substrate 11 can be reduced, thereby avoiding energy loss caused by secondary diffraction of the coupling-out region 13, and improving the display efficiency of the optical waveguide 10.
In one implementation of the embodiment of the present application, the grating is one of a surface relief grating and a volume holographic grating.
The embodiment of the application does not limit the specific structure of the grating, and an example can be one of a surface relief grating and a volume holographic grating, wherein the volume holographic grating has good wavelength selectivity and angle selectivity of incident light, and when the angle and wavelength of the incident light meet the Bragg condition, the diffraction efficiency of the volume holographic grating is high. The surface relief grating has a larger refractive index difference, can diffract light beams in a larger wavelength range, is arranged in the coupling-out area, ensures that the emergent light beams obtain a larger emergent angle, and further obtains a larger view field angle, and can be selected according to actual conditions by a person skilled in the art.
Optionally, at least two layers of waveguide substrates 11 are connected by a frame, and a gap is provided between two adjacent layers of waveguide substrates 11, wherein the gap is less than 0.1mm.
As shown in fig. 4 and 5, a small gap is formed between two adjacent waveguide substrates 11, and the gap enables the surface of each layer of optical waveguide 10 to be in contact with air, so that total reflection is facilitated, and in addition, the gap may be sufficiently small, for example, 0.06mm, 0.08mm, or the like, in order to reduce the volume of the optical waveguide 10.
It should be noted that, in order to more clearly show the structure of the optical waveguide 10, the frame is not shown in fig. 4, 5 and 6, and in practical application, at least the outer edges of the waveguide substrates 11 on both sides are connected by the frame.
In one implementation of the embodiment of the present application, the refractive index of the waveguide substrate 11 is 1.5-2.5, and the thickness is less than 1mm.
The thickness of the waveguide substrate 11 is less than 1mm, and the thickness of the waveguide substrate 11 can be reduced, thereby reducing the weight of the optical waveguide 10. In addition, the materials and dimensions of the waveguide substrate 11 may be the same or different. The person skilled in the art can set this according to the actual circumstances.
In another aspect of the present embodiment, a display assembly 20 is disclosed, including a light machine 21 and the optical waveguide 10 disposed on a light emitting side of the light machine 21, where the full-field light emitted from the light machine 21 is divided into a plurality of sub-beams with different angles of view corresponding to the waveguide substrates 11, and the plurality of sub-beams are coupled into the corresponding waveguide substrates 11 by the coupling-in regions and propagate in the waveguide substrates 11.
Alternatively, the projection of the sub-beam onto the corresponding waveguide substrate 11 falls within the corresponding coupling-in region 12 of the sub-beam.
In order to enable all sub-beams of different angles of view to enter the waveguide substrate 11 through the coupling-in region 12, embodiments of the present application project each sub-beam onto a corresponding waveguide substrate 11 such that the projection falls within the corresponding coupling-in region of the sub-beam. Specifically, the size of the coupling-in area 12 on the nth layer of waveguide substrate 11 along the total reflection propagation direction of the sub-beams is set to Cn, the size of the projection of the nth part of sub-beams on the surface of the nth layer of waveguide substrate 11 along the total reflection propagation direction of the sub-beams is Zn, cn is greater than or equal to Zn, so that each coupling-in area 12 can completely receive the sub-beams of each view angle, and light leakage is avoided.
In one implementation manner of the embodiment of the present application, as shown in fig. 5, the dimension of the projection of the full-field light onto the waveguide substrate 11 farthest from the optical machine along the width direction is Ln, the dimension of a shadow formed by splicing the projections of the multiple coupling-in areas on the surface of the optical waveguide along the width direction is L1, the dimension of the exit pupil plane of the full-field light along the width direction is L2, and Ln, L1, L2 satisfies the relation Ln > L1> L2, where the width direction is the total reflection propagation direction of the sub-beams in the waveguide substrate.
As shown in fig. 5, the total width of the shadow formed by the projection splice of the orthographic projections of all the coupling-in areas 12 on the surface of the optical waveguide is L1 along the width direction, the width of the surface of the exit pupil of the optical bench 21 is L2, and the width of the projection area of the full-field light projected on the waveguide substrate farthest from the optical bench is Ln, and in the embodiment of the present application, L2< L1< Ln, all the coupling-in areas 12 can receive all the full-field light emitted from the optical bench 21, so as to avoid the leakage of the light beam.
The embodiment of the application also discloses an AR device, which comprises a light machine 21 and the optical waveguide 10 arranged on the light emitting side of the light machine 21, or comprises the display component, wherein the full-view light emitted by the light machine 21 is transmitted by the optical waveguide 10 and then emitted, and is received by human eyes in a preset area at a target distance. The AR device includes the same structure and advantages as the optical waveguide 10 in the previous embodiment. The structure and advantageous effects of the optical waveguide 10 have been described in detail in the foregoing embodiments, and are not described in detail herein.
The above description is only of the preferred embodiments of the present application and is not intended to limit the present application, but various modifications and variations can be made to the present application by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the protection scope of the present application.
Claims (10)
1. The optical waveguide is characterized by comprising at least two layers of waveguide substrates, wherein each waveguide substrate is provided with a coupling-in area and a coupling-out area, orthographic projections of the coupling-in areas of two adjacent waveguide substrates are staggered, the coupling-in areas of the waveguide substrates are used for corresponding sub-beams with different view angles in the total-view-field light emitted by an optical machine, so that the sub-beams with the corresponding view angles are coupled in, are coupled out from the coupling-out area after being subjected to at least one total reflection in the waveguide substrates, and cover a preset area at a target distance, wherein the propagation distance of the sub-beams entering the waveguide substrates from the coupling-in areas on the surfaces of the waveguide substrates through one total reflection is larger than the propagation distance of the coupling-in areas along the sub-beam propagation direction.
2. Optical waveguide according to claim 1, characterized in that the coupling-in and coupling-out regions of the waveguide substrate are each provided with a grating, the duty cycle and/or the depth and/or the tilt angle of the gratings of the coupling-in regions of different waveguide substrates being different.
3. The optical waveguide of claim 1, wherein the coupling-out regions of the waveguide substrates are all the same size and the orthographic projections of the coupling-out regions of adjacent two of the waveguide substrates overlap each other.
4. The optical waveguide of claim 1, wherein the coupling-out regions of the waveguide substrates are of different sizes, and the orthogonal projections of the coupling-out regions of adjacent two of the waveguide substrates are offset.
5. The optical waveguide of claim 1, wherein at least two layers of the waveguide substrates are connected by a frame with a gap between adjacent layers of the waveguide substrates of less than 0.1mm.
6. The optical waveguide of claim 1, wherein the waveguide substrate has a refractive index of 1.5-2.5 and a thickness of less than 1mm.
7. A display assembly, comprising a light engine and the optical waveguide of any one of claims 1-6 disposed on a light-emitting side of the light engine, wherein the light emitted from the light engine is divided into a plurality of sub-beams with different angles of view corresponding to the waveguide substrate, and the plurality of sub-beams are coupled into the corresponding waveguide substrate by coupling-in regions and propagate in the waveguide substrate.
8. The display assembly of claim 7, wherein the projection of the sub-beams onto the corresponding waveguide substrate falls within the range of the corresponding incoupling region.
9. The display assembly of claim 8, wherein the projection of the full field light onto the waveguide substrate furthest from the light engine has a width direction dimension Ln, the projection of the coupling-in regions onto the surface of the light waveguide is spliced to form a shadow having a width direction dimension L1, and the exit pupil plane of the full field light has a width direction dimension L2, ln, L1, L2 satisfying a relationship Ln > L1> L2, wherein the width direction is a total reflection propagation direction of the sub-beams within the waveguide substrate.
10. An AR device, comprising a light engine and the optical waveguide of any one of claims 1-6 disposed on the light exit side of the light engine, or the display assembly of any one of claims 7-9, wherein the light emitted from the light engine in the full field of view is transmitted through the optical waveguide and then emitted and received by the human eye in a preset area at a target distance.
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN117148594A (en) * | 2023-10-31 | 2023-12-01 | 深圳市光舟半导体技术有限公司 | Display assembly and AR equipment |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN117148594A (en) * | 2023-10-31 | 2023-12-01 | 深圳市光舟半导体技术有限公司 | Display assembly and AR equipment |
| CN117148594B (en) * | 2023-10-31 | 2024-01-02 | 深圳市光舟半导体技术有限公司 | Display assembly and AR equipment |
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