CN117555064A - AR optical waveguide and AR device - Google Patents

Abstract

The invention provides an AR optical waveguide and AR equipment, comprising: a waveguide substrate, an input coupler, an output coupler, and an additional optical element; wherein the input coupler is configured to couple the image beam into the waveguide substrate; the output coupler is configured to diffractively couple the light beam transmitted within the waveguide substrate out of the first face of the waveguide substrate; the additional optical element is arranged on the second surface of the waveguide substrate, and the period of the additional optical element is consistent with that of the output coupler. The technical scheme of the invention can greatly relieve the light leakage problem and even eliminate the light leakage; and the light beam originally leaked on the second surface can be re-coupled into the waveguide substrate for transmission, and at least part of the light beam re-coupled into the waveguide substrate can be coupled out from the first surface, so that the energy originally leaked is re-utilized, and the light energy utilization rate can be improved.

Description

AR optical waveguide and AR device

Technical Field

The invention relates to the technical field of optical waveguides, in particular to an AR optical waveguide and AR equipment.

Background

Optical waveguide display technology is one of the most challenging and complex problems in the Augmented Reality (AR) field, and is considered as an optical solution of consumer-grade AR glasses due to its thinness and high transmittance of external light.

In the augmented reality display system, after the light beam propagating in the waveguide element is diffracted in the coupling-out grating area, a part of the light beam exits into the human eye, and the other part of the light beam continues to propagate through total reflection, in the coupling-out grating area, due to the grating diffraction effect, the reflection order and the transmission order exist simultaneously, please refer to fig. 1, the coupling-out grating is arranged on the surface close to one side of the human eye, the transmission order effectively couples out the order into the human eye, the reflection order is coupled out from the surface away from one side of the human eye, so that part of light leaks, and the outside can also see the content watched by the AR optical waveguide user, thereby not only affecting the beauty, but also causing the privacy leakage of the user.

In addition, leakage of light also causes energy waste.

Disclosure of Invention

The invention provides an AR optical waveguide and AR equipment, which are used for solving the problems of light leakage and energy waste in the existing optical waveguide.

According to a first aspect of the present invention, there is provided an AR optical waveguide comprising: a waveguide substrate, an input coupler, an output coupler, and an additional optical element; wherein,

the input coupler is disposed on the waveguide substrate and configured to couple an image beam into the waveguide substrate;

the output coupler is disposed on the waveguide substrate and configured to diffractively couple out an image beam transmitted within the waveguide substrate from a first face of the waveguide substrate;

the additional optical element is arranged on the second surface of the waveguide substrate, and the period of the additional optical element is consistent with that of the output coupler; the additional optical element is configured to enable diffraction orders leaking from the second face of the waveguide substrate to produce a diffracted beam on the additional optical element, and at least a portion of the diffracted beam can be re-coupled back into the waveguide substrate for transmission and re-coupled out of the first face of the waveguide substrate by the output coupler;

the first surface of the waveguide substrate is the surface of the waveguide substrate, which is close to one side of human eyes; the output coupler is arranged on the first surface; the second surface of the waveguide substrate is the surface of the side, away from the human eyes, of the waveguide substrate; the leaked diffraction order is a reflection order generated by the diffraction of the image beam by the output coupler.

Preferably, the input coupler is disposed on the first face and/or the second face of the waveguide substrate; the area where the additional optical element is located covers at least the area where the output coupler is located.

Preferably, the output coupler is an output grating; the additional optical element is an additional grating; the input coupler is an input grating;

the grating direction of the additional grating is the same as the grating direction of the output grating, or the grating direction of the additional grating is the same as the partial grating direction of the output grating.

Preferably, the additional optical element has a diffraction efficiency for light beams within a predetermined wavelength range that is greater than a diffraction efficiency for light beams outside the predetermined wavelength range; the preset wavelength range is a wavelength range of the image light beam.

Preferably, the additional optical element approaches zero diffraction efficiency for light beams outside the wavelength range of the image light beam.

Preferably, the additional optical element comprises a plurality of layers; the preset wavelength range corresponding to each layer of the additional optical element is a sub-range of the wavelength range of the image light beam and is different from each other.

Preferably, the diffraction efficiency of the additional optical element for the light beam within the preset incident angle range is greater than the diffraction efficiency for the light beam outside the preset incident angle range; the preset incident angle range is an incident angle range when the leaked diffraction order is incident to the second surface of the waveguide substrate.

Preferably, the additional optical element has a diffraction efficiency approaching zero for a light beam in the total reflection angle range.

Preferably, the additional optical element is a zoned additional optical element;

the zoned additional optical element is configured to: enabling the diffracted light beams transmitted in the waveguide substrate at different positions to be re-coupled back to propagate towards the eye movement range; or,

the zoned additional optical element is configured to: the diffraction efficiency of the diffraction orders propagating toward the eye's range can be maximized among the multiple diffraction orders propagating back into the waveguide substrate at each location.

Preferably, the zoned additional optical element comprises at least two additional optical elements arranged in zones;

the output coupler is a two-dimensional output grating, the at least two additional optical elements are one-dimensional additional gratings, the grating direction of the one-dimensional additional gratings is the same as one of the two-dimensional output gratings, and the grating period is the same as the grating period of the two-dimensional output grating in the grating direction;

the grating direction of the one-dimensional additional gratings of different partitions is configured to: the diffraction light beams transmitted in the waveguide substrate from the subarea where the one-dimensional additional grating is located, diffracted and recoupled by the one-dimensional additional grating, can be transmitted towards the eye movement range.

Preferably, the zoned additional optical element comprises at least two additional optical elements arranged in zones;

the output coupler is a two-dimensional output grating, the at least two additional optical elements are two-dimensional additional gratings, the grating direction of the two-dimensional additional gratings is the same as that of the two-dimensional output grating, and the grating period of the two-dimensional additional gratings is the same as that of the two-dimensional output grating;

the grating parameters of the two-dimensional additional gratings of different partitions are configured to: the diffraction efficiency of the diffraction orders propagating towards the eye movement range can be maximized from the subarea where the two-dimensional additional grating is located, the diffraction orders being diffracted and re-coupled back by the two-dimensional additional grating into the plurality of diffraction orders transmitted in the waveguide substrate.

According to a second aspect of the present invention, there is provided an AR device comprising: the AR optical waveguide of any one of the above.

According to the AR optical waveguide and the AR equipment provided by the invention, the diffraction orders leaked from the surface of the waveguide substrate, which is far away from the human eyes, can be generated on the additional optical element by the additional optical element, and the diffraction beams are re-coupled into the waveguide substrate for transmission, so that the problem of light leakage can be greatly relieved, and even the light leakage is eliminated; in addition, the period of the additional optical element is consistent with that of the output coupler, so that the generated partial diffracted light beams can be coupled back into the waveguide substrate for transmission, and can be coupled out from the surface of the waveguide substrate, which is close to one side of the human eye, through the output coupler, namely, the originally leaked energy can be reused, and the light energy utilization rate is improved.

In an alternative of the invention, the additional optical element has a high degree of wavelength selectivity, i.e. a diffraction efficiency for light beams within a predetermined wavelength range, which may be the wavelength range of the image light beam, is greater than for light beams outside the predetermined wavelength range. Thus, when the external environment light (i.e., the light outside the preset wavelength range) enters the human eye through the additional optical element, the diffraction response of the additional optical element to the external environment light can be reduced.

In an alternative of the present invention, the additional optical element has a high degree of angular selectivity, i.e. the diffraction efficiency for light beams within a predetermined range of angles of incidence is greater than for light beams outside the predetermined range of angles of incidence, the predetermined range of angles of incidence being the range of diffraction orders of the leakage; therefore, the energy of the leaked diffraction order can be better utilized again for the high diffraction efficiency of the incidence angle range of the leaked diffraction order, the diffraction efficiency of the light beam which is totally reflected in the waveguide substrate and is incident to the additional optical element is low or the diffraction effect is not generated, and the total reflection transmission of the image light beam in the waveguide substrate is basically not influenced.

In an alternative scheme of the invention, the additional optical elements can be arranged in a partitioning manner, and different additional optical elements are arranged in different areas according to the position relation between the output coupler and the eye movement range (Eyebox), so that light beams transmitted in the echo guide substrate can be transmitted towards the eye movement range to the greatest extent through the recoupling of the additional optical elements at all positions, and further, the light beams are coupled to the eye movement range through the output coupler on the surface of the waveguide substrate, which is close to one side of the human eye, and the light utilization rate is further improved.

Drawings

In order to more clearly illustrate the embodiments of the invention or the technical solutions of the prior art, the drawings which are used in the description of the embodiments or the prior art will be briefly described, it being obvious that the drawings in the description below are only some embodiments of the invention, and that other drawings can be obtained according to these drawings without inventive faculty for a person skilled in the art.

FIG. 1 is a schematic diagram of a prior art light leak;

FIG. 2 is a schematic diagram of an AR optical waveguide according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of an AR optical waveguide according to a preferred embodiment of the present invention;

FIG. 4a is a diagram of the coupling-in K domain of an AR optical waveguide according to a preferred embodiment of the present invention;

FIG. 4b is a coupled-out K-domain view of an AR optical waveguide according to a preferred embodiment of the present invention;

FIG. 4c is a leakage order out-coupling K-field plot of an AR optical waveguide according to a preferred embodiment of the present invention;

FIG. 4d is a K-domain plot of leakage order re-coupling of an AR optical waveguide back to the waveguide substrate in accordance with a preferred embodiment of the present invention;

FIG. 5a is a diagram of the coupling-in K domain of an AR optical waveguide according to another preferred embodiment of the present invention;

FIG. 5b is a pupil-expanding K-domain view of an AR optical waveguide according to another preferred embodiment of the present invention;

FIG. 5c is a coupled-out K-domain view of an AR optical waveguide according to another preferred embodiment of the present invention;

FIG. 5d is a leakage order out-coupling K-domain plot of an AR optical waveguide according to another preferred embodiment of the present invention;

FIG. 5e is a K-domain plot of leakage order re-coupling of an AR optical waveguide back to a waveguide substrate in accordance with another preferred embodiment of the present invention;

FIG. 6 is a schematic illustration of the high selectivity of wavelengths of an AR optical waveguide according to a preferred embodiment of the present invention;

FIG. 7 is a schematic diagram of an AR optical waveguide according to a preferred embodiment of the present invention;

FIG. 8 is a schematic view showing a high degree of angular selectivity of an AR optical waveguide according to a preferred embodiment of the present invention;

FIG. 9 is a schematic view of an Eyebox;

FIG. 10 is a schematic diagram of an input grating and an output grating according to an embodiment of the present invention;

FIG. 11a is a schematic diagram of an additional grating, which is a one-dimensional grating and is not partitioned, according to an embodiment of the present invention;

FIG. 11b is a schematic diagram of an additional grating according to an embodiment of the present invention, which is a two-dimensional grating and is not partitioned;

FIG. 12a is a schematic diagram of a one-dimensional grating with partitions as an additional grating according to an embodiment of the present invention;

FIG. 12b is a schematic diagram of an additional grating according to an embodiment of the present invention, which is a two-dimensional grating and is partitioned;

reference numerals illustrate:

1-a substrate for a waveguide,

a 2-input coupler, the input coupler,

a 3-output coupler, the output coupler,

4-additional optical element.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

In the description of the present specification, it should be understood that the directions or positional relationships indicated by the terms "upper", "lower surface", "upper surface", etc. are based on the directions or positional relationships shown in the drawings, are merely for convenience of description and simplification of description, and do not indicate or imply that the apparatus or element to be referred to must have a specific direction, be configured and operated in a specific direction, and thus should not be construed as limiting the present invention.

In the description of the present specification, the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature.

In the description of the present invention, the meaning of "plurality" means a plurality, for example, two, three, four, etc., unless explicitly specified otherwise.

In the description of the present invention, unless explicitly stated and limited otherwise, the term "coupled" and the like should be construed broadly, and may be, for example, fixedly coupled, detachably coupled, or integrally formed; may be mechanically connected, may be electrically connected or may communicate with each other; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.

The technical scheme of the invention is described in detail below by specific examples. The following embodiments may be combined with each other, and some embodiments may not be repeated for the same or similar concepts or processes.

In one embodiment, an AR optical waveguide is provided, comprising: reference is made to fig. 2 for a waveguide substrate 1, an input coupler 2, an output coupler 3, and an additional optical element 4. Wherein the input coupler 2 is arranged on the waveguide substrate 1 and is configured to be able to couple an image beam into said waveguide substrate 1; the output coupler 3 is arranged on said waveguide substrate 1 and is configured to be able to diffractively couple out the light beam transmitted within the waveguide substrate 1 from the first side of the waveguide substrate 1. The additional optical element 4 is arranged on the second surface of the waveguide substrate, and the period of the additional optical element 4 is consistent with that of the output coupler 3; the additional optical element 4 is configured such that the diffraction orders leaking from the second face of the waveguide substrate 1 produce a diffracted beam on the additional optical element, and at least part of the diffracted beam can be re-coupled back into the waveguide substrate 1 for transmission and re-coupled out by diffraction through the output coupler 3. The first surface of the waveguide substrate 1 is the surface of the waveguide substrate 1 close to one side of human eyes; the output coupler 3 is arranged on the first surface; the second surface of the waveguide substrate 1 is the surface of the side of the waveguide substrate 1 facing away from the human eyes; the leaked diffraction order is a reflection order generated by the diffraction of the image beam by the output coupler 3. The transmission principle of the AR optical waveguide of the above embodiment is: after the input coupler couples the image beam into the waveguide substrate, it is transmitted in the waveguide substrate to the region where the output coupler is located with total reflection. When the image light beam is incident on the output coupler, diffraction beam splitting occurs, and part of the image light beam continues to be transmitted in the waveguide substrate in a total internal transmission mode (R0 diffraction order), wherein at least one diffraction order diffraction light beam can be coupled out of the waveguide substrate, namely the coupling-out order, and the other diffraction order diffraction light beam can be transmitted out of the waveguide substrate from the second surface of the waveguide substrate, namely the leakage order. After the additional optical element is arranged on the second surface, the leakage order is incident on the additional optical element to generate diffraction beam splitting, at least one diffraction beam with the diffraction order can be re-coupled into the waveguide substrate to be transmitted, and when the re-coupled diffraction beam with the diffraction order is incident on the output coupler again, the additional optical element is consistent with the period of the output coupler, the waveguide substrate can be coupled out of the first surface of the waveguide substrate, so that the originally leaked energy can be reused, the light leakage is reduced to a certain extent, and the light energy utilization efficiency of the whole diffraction optical waveguide can be improved.

In one embodiment, the input coupler 2 may be disposed on a first surface of the waveguide substrate, as shown in fig. 2. In various embodiments, the input coupler 2 may be disposed on the second surface of the waveguide substrate, or the input coupler 2 may be disposed on both the first and second surfaces of the waveguide substrate.

In one embodiment, the input coupler 2 and the output coupler 3 are disposed at different sections of the waveguide substrate 1, please refer to fig. 2.

In an embodiment, the area where the additional optical element 4 is located covers the area where the output coupler 3 is located, i.e.: the additional optical element 4 covers a section of the waveguide substrate 1 where the output coupler 3 is arranged. The additional optical element 4 may cover only a section of the waveguide substrate 1 where the output coupler 3 is arranged, see fig. 2. In various embodiments, the additional optical element 4 may also cover more than just a section of the waveguide substrate 1 where the output coupler 3 is arranged, such as: the entire section of the waveguide substrate 1 may be covered.

In one embodiment, the output coupler 3 is an output grating; the additional optical element 4 is an additional grating, please refer to fig. 3.

In one embodiment, the input coupler 2 is an input grating, please refer to fig. 3.

In one embodiment, the input grating, the output grating, the additional grating may be a surface relief grating, a bulk grating, or the like.

In an embodiment, the grating direction of the additional grating is the same as the grating direction of the output grating, or the grating direction of the additional grating is the same as a part of the grating direction of the output grating.

The following is a detailed description in connection with two specific examples:

in one embodiment, the in-coupling grating and the out-coupling grating are both one-dimensional gratings. Specifically, the K-domain plot of the propagation of an image beam in a waveguide substrate is shown in fig. 4a-4 d. The image beam exiting from the optical machine is coupled into the waveguide for total reflection transmission through the coupling-in grating (Kin) as shown in fig. 4a, and is coupled out into the human eye on the surface of the coupling-out grating (Kout) as shown in fig. 4b. While coupled out, leakage orders are generated, and leakage images forming a dashed box emerge away from the human eye, as shown in fig. 4c. At this time, to reuse the leakage order, the additional grating on the side of the waveguide facing away from the eye should also be a one-dimensional grating, and the grating period and the grating direction of the additional grating are the same as those of the coupling-out grating, so that the additional grating (Kadd) can couple the light leakage image back into the waveguide again, as shown in fig. 4d, and continue transmission, and realize coupling-out into the human eye on the surface of the coupling-out grating (Kout) in the subsequent path, as shown in fig. 4b. Furthermore, the outcoupled light beam, which is only coupled out by the action of the outcoupling grating, has the same field of view as the outcoupled light beam, which is subjected to the action of the additional grating and the outcoupling grating, and the outcoupled light beam is enhanced.

In one embodiment, the coupling-in grating is a one-dimensional grating and the coupling-out grating is a two-dimensional grating. Specifically, K-domain diagrams of the propagation of an image beam in a waveguide substrate are shown in fig. 5a-5 e. The image beam emitted by the optical machine is coupled into the waveguide for total reflection transmission through the coupling-in grating (Kin), as shown in fig. 5a, and the pupil expansion (as shown in fig. 5 b) and the coupling-out (as shown in fig. 5 c) are realized on the surface of the coupling-out grating (Kout) to enter the human eye. While coupled out, leakage orders are generated, and leakage images forming a dashed box emerge away from the human eye, as shown in fig. 5d. At this time, to reuse the leakage order, the additional grating on the side of the waveguide facing away from the eye may be a one-dimensional grating, and the grating direction of the additional grating is the same as one of the coupling-out gratings, and the grating period of the additional grating is the same as the grating period of the coupling-out grating in the grating direction, so that the additional grating (Kadd) may re-couple the light leakage image back into the waveguide, as shown in fig. 5e, and continue to transmit, and realize the coupling-out into the human eye on the surface of the coupling-out grating (Kout) in the subsequent path, as shown in fig. 5c. In a further embodiment, the additional grating on the side of the waveguide facing away from the eye may also be a two-dimensional grating, in which case it coincides with the outcoupling grating.

It will be appreciated that for AR devices, on the one hand, the image beam is coupled out of the waveguide into the human eye by total reflection propagation at the AR waveguide, and on the other hand, the real world beam is transmitted through the waveguide substrate into the human eye, enabling superposition of virtual and real content. The additional optical element provided by the invention is used for eliminating and utilizing the leaked image light beam of the waveguide away from the eye side, so that on one hand, the leaked image light beam can be eliminated and utilized as much as possible, and on the other hand, the additional optical element can influence the propagation of the real world light beam as little as possible.

In one embodiment, the diffraction efficiency of the additional optical element for the light beam within the predetermined wavelength range is greater than the diffraction efficiency for the light beam outside the predetermined wavelength range, please refer to fig. 6. The additional optical element thus has a high selectivity of the wavelength.

In an embodiment, the predetermined wavelength range is a wavelength range of the image beam, that is, the additional grating has high diffraction efficiency mainly in the wavelength range of the image beam emitted from the optical machine. Preferably, the diffraction efficiency of the additional optical element for the light beam outside the wavelength range of the image light beam approaches zero, so that more leakage-order image light beams can be re-coupled into the waveguide substrate, the energy of the leakage-order image light beams can be better utilized again, the diffraction efficiency of the wavelength range outside the image light beam emitted by the optical machine is low, and the diffraction response of the additional grating to the external environment light can be reduced when the external environment light enters the human eye through the additional grating.

In one embodiment, the additional optical element comprises multiple layers; the preset wavelength range corresponding to each layer of the additional optical element is a sub-range of the wavelength range of the image light beam and is different from each other. Such as: for the AR optical waveguide of full-color display, the additional grating may include three layers, and referring to fig. 7, the three layers of additional grating have higher diffraction efficiency in three wavelength ranges of red (R), green (G), and blue (B), respectively.

In one embodiment, the diffraction efficiency of the additional optical element for the light beam within the predetermined incident angle range is greater than the diffraction efficiency for the light beam outside the predetermined incident angle range; the predetermined incident angle range is the incident angle range of the leaked diffraction order, please refer to fig. 8. The accessory optical element is thus highly angularly selective.

In one embodiment, the diffraction efficiency of the additional optical element for the light beam within the predetermined incident angle range is much greater than the diffraction efficiency for the light beam outside the predetermined incident angle range. Preferably, the additional optical element has a diffraction efficiency approaching zero for a light beam in the total reflection angle range, i.e. a high diffraction efficiency mainly for the incidence angle range of the leakage image, whereas no diffraction effect is exerted on the light rays incident to the additional optical element by total reflection within the waveguide. As shown in fig. 8, the incident angle is the angle at which the image beam propagating in the waveguide substrate is incident on the additional optical element. The image light Beam incident on the additional optical element comprises a part of light Beam1 which continues to transmit in the waveguide substrate in a total reflection way after the output coupler acts, and diffraction order (leakage order) Beam2 which is not coupled out of the waveguide substrate after the output coupler acts and cannot transmit in a total reflection way, the incident angle of Beam1 is in a total reflection angle area, the diffraction efficiency of the additional optical element is low, the total reflection transmission of the additional optical element in the waveguide substrate is not affected basically, the diffraction efficiency of the additional optical element on the incident angle of Beam2 is high, and the energy of the leakage order can be utilized again well.

In an embodiment, the additional optical elements are zoned, i.e. the additional optical elements are zoned, so that the diffracted light beams transmitted in the echo guiding substrate can be transmitted towards the eye movement range (Eyebox) to the maximum extent through the additional optical elements, and then coupled out to the eye movement range through the output coupler on the surface of the waveguide substrate near the human eye side to enter the human eye for effective use, and fig. 9 is a schematic diagram of the Eyebox, in which S1 represents the surface near the human eye side.

Fig. 10 shows a schematic view of the arrangement of the coupling-in grating and the coupling-out grating of the waveguide substrate near the surface S1 of the human eye side, 11a, 11b, a schematic view of the non-zoned arrangement of the additional optical element, 12a,12b, and a schematic view of the zoned arrangement of the additional optical element, where S2 represents the surface away from the human eye side.

In an embodiment, the input grating is a one-dimensional grating and the output grating is a two-dimensional grating, and when the additional optical elements are not arranged in a partitioned manner, the additional optical elements are one-dimensional gratings, please refer to fig. 11a, and the additional optical elements are two-dimensional gratings, please refer to fig. 11b.

When the additional optical element is arranged in a partitioned manner, the additional optical element is a one-dimensional grating, and the one-dimensional grating is modulated in a partitioned manner in the grating direction, please refer to fig. 12a, the grating directions of the one-dimensional gratings in different areas are modulated, and the additional grating 1, the additional grating 2 and the additional grating 3 enable the diffracted light beams in the light waveguide re-coupled back at different positions to propagate towards the Eyebox direction, i.e. the image light beams can be coupled out in the Eyebox area and received by human eyes. The additional optical element is a two-dimensional grating, and by dividing the diffraction efficiency of the two-dimensional grating, please refer to fig. 12b, the diffraction efficiencies of different diffraction orders of the two-dimensional grating in different areas are modulated, so that the diffraction efficiency of the diffraction order propagating towards the Eyebox direction is the highest, and thus more image light beams can be coupled out in the Eyebox area and received by human eyes. In the one-dimensional grating zonal modulation, the diffraction efficiency may be modulated synchronously.

The diffraction efficiency can be realized by modulating the duty ratio, depth and tooth shape of the grating.

In an embodiment, the zoned additional optical element comprises at least two zoned arrangements, each zone having an additional optical element arranged therein, i.e. comprising at least two additional optical elements, the parameters of the additional optical elements of different zones being different.

The following describes in detail two specific examples.

In one embodiment, for the optical waveguides of at least two subareas of the additional optical elements, the output coupler is a two-dimensional output grating, and at least two additional optical elements are one-dimensional additional gratings. The grating direction of the one-dimensional additional grating is the same as one of the two-dimensional output gratings, and the grating period is the same as the grating period of the two-dimensional output grating in the grating direction.

The grating directions of the one-dimensional additional gratings in different partitions are modulated, so that diffracted light beams transmitted in the echo guide substrate are diffracted and re-coupled by the one-dimensional additional gratings from the partition where the one-dimensional additional gratings are located, and the diffracted light beams propagate towards the eye movement range.

For example, for a side-projection display configuration, the additional optical element may be divided into two zone arrangements, and for an up-projection display configuration, the additional optical element may be divided into three zone arrangements.

In one embodiment, for the additional optical element including at least two optical waveguides arranged in a partitioned manner, the output coupler is a two-dimensional output grating, and at least two additional optical elements are two-dimensional additional gratings. The grating direction of the two-dimensional additional grating is the same as the grating direction of the two-dimensional output grating, and the grating period of the two-dimensional additional grating is the same as the grating period of the two-dimensional output grating.

Wherein grating parameters of two-dimensional additional gratings of different partitions are modulated, such as: the diffraction efficiency of diffraction orders in different directions can be modulated by modulating the duty ratio, the depth and the tooth shape, so that the diffraction efficiency of diffraction orders propagating towards the eye movement range is highest from a plurality of diffraction orders transmitted in the echo guide substrate after being diffracted and re-coupled by the two-dimensional additional grating from the subarea where the two-dimensional additional grating is positioned.

In the above embodiments, the two-dimensional grating is taken as an example for both the output coupler and the additional optical element, and in different embodiments, the output coupler and the additional optical element may also be higher-dimension gratings, and the design principle is the same as that of the two-dimensional grating, which is not described herein.

In an embodiment, there is also provided an AR apparatus, comprising: the AR optical waveguide of any of the embodiments above.

In one embodiment, the AR device may further include: an apparatus body and a light machine. The equipment main body is used for bearing the AR optical waveguide and the optical machine; the optical machine is used for projecting an image beam.

In an embodiment, the apparatus body may be implemented as a spectacle frame, wherein the spectacle frame comprises a beam portion and a temple portion, and the temple portion extends rearward from at least one of the left and right sides of the beam portion, wherein the diffractive optical waveguide is correspondingly provided to the beam portion.

In one embodiment, the apparatus body may be implemented as a windshield, and the AR optical waveguide is correspondingly disposed on the inner side of the windshield, so that the image beam projected through the optical machine is projected to the windshield after being transmitted through the AR optical waveguide to form a virtual image.

In the description of the present specification, the descriptions of the terms "one embodiment," "an embodiment," "a particular implementation," "an example," and the like, mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiments or examples. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present invention, and not for limiting the same; although the invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some or all of the technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the invention.

Claims (12)

1. An AR optical waveguide, comprising: a waveguide substrate, an input coupler, an output coupler, and an additional optical element; wherein,

the input coupler is disposed on the waveguide substrate and configured to couple an image beam into the waveguide substrate;

the output coupler is disposed on the waveguide substrate and configured to diffractively couple out an image beam transmitted within the waveguide substrate from a first face of the waveguide substrate;

the additional optical element is arranged on the second surface of the waveguide substrate, and the period of the additional optical element is consistent with that of the output coupler; the additional optical element is configured to enable diffraction orders leaking from the second face of the waveguide substrate to produce a diffracted beam on the additional optical element, and at least a portion of the diffracted beam can be re-coupled back into the waveguide substrate for transmission and re-coupled out of the first face of the waveguide substrate by the output coupler;

the first surface of the waveguide substrate is the surface of the waveguide substrate, which is close to one side of human eyes; the output coupler is arranged on the first surface; the second surface of the waveguide substrate is the surface of the side, away from the human eyes, of the waveguide substrate; the leaked diffraction order is a reflection order generated by the diffraction of the image beam by the output coupler.

2. The AR optical waveguide according to claim 1, wherein the input coupler is disposed at the first face and/or the second face of the waveguide substrate; the area where the additional optical element is located covers at least the area where the output coupler is located.

3. The AR optical waveguide of claim 1, wherein the output coupler is an output grating; the additional optical element is an additional grating; the input coupler is an input grating;

the grating direction of the additional grating is the same as the grating direction of the output grating, or the grating direction of the additional grating is the same as the partial grating direction of the output grating.

4. The AR optical waveguide according to any one of claims 1 to 3, wherein the additional optical element has a diffraction efficiency for a light beam within a predetermined wavelength range that is greater than a diffraction efficiency for a light beam outside the predetermined wavelength range; the preset wavelength range is a wavelength range of the image light beam.

5. The AR optical waveguide of claim 4, wherein the additional optical element has a diffraction efficiency approaching zero for a light beam outside the wavelength range of the image light beam.

6. The AR optical waveguide of claim 4, wherein the additional optical element comprises multiple layers; the preset wavelength range corresponding to each layer of the additional optical element is a sub-range of the wavelength range of the image light beam and is different from each other.

7. The AR optical waveguide according to any one of claims 1 to 3, wherein the additional optical element has a diffraction efficiency for light beams within a predetermined range of angles of incidence that is greater than a diffraction efficiency for light beams outside the predetermined range of angles of incidence; the preset incident angle range is an incident angle range when the leaked diffraction order is incident to the second surface of the waveguide substrate.

8. The AR optical waveguide of claim 7, wherein the additional optical element has a diffraction efficiency approaching zero for a light beam in the total reflection angle range.

9. The AR optical waveguide according to any one of claims 1 to 3, wherein the additional optical element is a zoned additional optical element;

the zoned additional optical element is configured to: enabling the diffracted light beams transmitted in the waveguide substrate at different positions to be re-coupled back to propagate towards the eye movement range; or,

the zoned additional optical element is configured to: the diffraction efficiency of the diffraction orders propagating toward the eye's range can be maximized among the multiple diffraction orders propagating back into the waveguide substrate at each location.

10. The AR optical waveguide of claim 9, wherein the zoned additional optical element comprises at least two additional optical elements arranged in zones;

the output coupler is a two-dimensional output grating, the at least two additional optical elements are one-dimensional additional gratings, the grating direction of the one-dimensional additional gratings is the same as one of the two-dimensional output gratings, and the grating period is the same as the grating period of the two-dimensional output grating in the grating direction;

the grating direction of the one-dimensional additional gratings of different partitions is configured to: the diffraction light beams transmitted in the waveguide substrate from the subarea where the one-dimensional additional grating is located, diffracted and recoupled by the one-dimensional additional grating, can be transmitted towards the eye movement range.

11. The AR optical waveguide of claim 9, wherein the zoned additional optical element comprises at least two additional optical elements arranged in zones;

the output coupler is a two-dimensional output grating, the at least two additional optical elements are two-dimensional additional gratings, the grating direction of the two-dimensional additional gratings is the same as that of the two-dimensional output grating, and the grating period of the two-dimensional additional gratings is the same as that of the two-dimensional output grating;

the grating parameters of the two-dimensional additional gratings of different partitions are configured to: the diffraction efficiency of the diffraction orders propagating towards the eye movement range can be maximized from the subarea where the two-dimensional additional grating is located, the diffraction orders being diffracted and re-coupled back by the two-dimensional additional grating into the plurality of diffraction orders transmitted in the waveguide substrate.

12. An AR device, comprising: the AR optical waveguide of any one of claims 1 to 11.