Augmented reality display device

Abstract

An augmented reality display device (100) includes: an optical engine (102) for emitting image light rays; at least one optical waveguide lens (101) including an insertion grating region (1012), an optical waveguide substrate (1011), and a deflection and coupling grating region (1013), wherein the insertion grating region (1012) is disposed on a first optical surface of the optical waveguide substrate (1011); the optical waveguide substrate (1011) is used to transmit image light rays by total internal reflection; the deflection and coupling grating region (1013) is disposed on the first optical surface of the optical waveguide substrate (1011), receives total internal reflection light, and couples it out; the sum of the insertion grating vector and the deflection and coupling grating vector is not zero, wherein the insertion angle of the optical engine (102) and each optical waveguide lens (101) is the same. This allows the optical engine (102) and the optical waveguide lens (101) to still coincide in the center field of view of the optical engine (102) with the center field of view of the human eye even when they are not perpendicularly coupled. This greatly increases the freedom of design for the structure of the optical engine (102) and the optical waveguide lens (101), thereby making the structure of the augmented reality display device (100) more diverse and the manufactured display device smaller in size.

Description

Technical Field

[0001] This application relates to the field of augmented reality technology, and more specifically, to an augmented reality display device. Background Technology

[0002] Currently, Augmented Reality (AR) technology integrates virtual information with the real world. Augmented Reality glasses, in particular, are gaining traction across various industries, especially in security and industrial sectors, where they offer unparalleled advantages and significantly improve information interaction. Mature AR technologies primarily fall into four categories: prism, birdbath, freeform surface, off-axis holographic lens, and waveguide. The first three are relatively bulky, limiting their application in smart wearables, specifically AR glasses. Holographic lens solutions utilize the unique optical properties of holograms, offering advantages such as a large field of view (FOV) and small size, but are limited by a relatively small eye movement range. Holographic waveguide solutions excel in color uniformity (no rainbow effect) and achieving full-color waveguides, but are currently limited in mass production and large field of view. Waveguides are currently the best solution for AR glasses. Waveguide solutions are further divided into geometric waveguides, embossed grating waveguides, and volume holographic waveguides. Geometric waveguide schemes generally include sawtooth waveguides and polarized thin-film array mirror waveguides (or simply polarized array waveguides). The mainstream polarized array waveguide uses a partially transmissive, partially reflective thin-film mirror array to achieve virtual information display. This scheme offers advantages such as thinness, a large eye-tracking range, and uniform color. Embossed grating waveguides can be mass-produced using nanoimprint lithography, offering advantages such as a large field of view and a wide eye-tracking range. However, this also presents challenges in achieving uniformity in both field of view and color, and the related micro / nano fabrication processes also pose significant challenges.

[0003] The inventors discovered that, typically, to make the central field of view of the optical engine coincide with the central field of view of the human eye, the optical engine needs to be perpendicularly coupled to the waveguide mirror. This method limits the freedom of structural design. Due to the limitations of the waveguide mirror and the optical engine itself, the field of view of the coupled image rays is relatively small.

[0004] The information disclosed in the background section is only intended to enhance the understanding of the background of this application, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0005] Based on this, this application provides an augmented reality display device, and addresses the dispersion problem of optical waveguide lenses by selecting a visible laser light source. The technical solution of this application ensures that the central field of view of the optical engine coincides with the central field of view of the human eye even when the optical engine and optical waveguide lenses are not perpendicularly coupled, greatly improving the freedom of design for the optical engine and optical waveguide lens structures.

[0006] The features and advantages of the technical solutions of this application will become apparent from the following detailed description, or may be learned in part from practice of this application.

[0007] According to one aspect of this application, an augmented reality display device is proposed, comprising: an optical engine for emitting image light rays; at least one optical waveguide lens for coupling in and deflecting and coupling out the image light rays emitted by the optical engine, the at least one optical waveguide lens comprising: a coupling grating region, an optical waveguide substrate, and a deflection and coupling out grating region, wherein the coupling grating region is disposed on a first optical surface of the optical waveguide substrate and receives the transmitted image light rays emitted by the optical engine; the optical waveguide substrate is used to transmit image light rays through total internal reflection; the deflection and coupling out grating region is disposed on the first optical surface of the optical waveguide substrate and receives and couples out the total internal reflection light transmitted by the optical waveguide substrate; the sum of the coupling grating vector and the deflection and coupling out grating vector is not zero, wherein the coupling angle between the optical engine and each optical waveguide lens layer is the same.

[0008] According to some embodiments, each layer of optical waveguide lens corresponds to an image light of a certain color.

[0009] According to some embodiments, the gratings in the transition and coupling grating regions must satisfy the following formula:

[0010]

[0011] in The angle θ between the optomechanical coupling direction and the normal of the surface of at least one optical waveguide lens, the wavelength of the transmitted image light is λ, the angle γ between the surface of at least one optical waveguide lens and the vertical direction, the coupling grating period Λ1, and the turning and coupling grating period Λ2.

[0012] According to some embodiments, the angle θ between the optical engine and the surface normal of at least one layer of optical waveguide lens ranges from 0° to 15°.

[0013] According to some embodiments, the angle γ between the surface of at least one optical waveguide lens and the vertical direction and the angle θ between the surface normal of at least one optical waveguide lens satisfy the following formula:

[0014] θ+γ≤20°

[0015] According to some embodiments, the transition and coupling grating region includes a one-dimensional surface relief grating or a two-dimensional surface relief grating.

[0016] According to some embodiments, the light source of the optomechanism transmits image light including visible laser light, and the dispersion of the optical waveguide lens is limited by the narrow linewidth characteristic of the light source.

[0017] According to some embodiments, the linewidth, insertion grating period, inflection grating period, and extraction grating period of the visible light laser satisfy the following formula:

[0018]

[0019] Where ε is the angular resolution of the human eye, θ is the angle between the optomechanical coupling direction and the normal of the surface of at least one optical waveguide lens, Λ1 is the coupling grating period, Λ2 is the turning and coupling grating period, and δλ is the linewidth of the visible laser.

[0020] According to some embodiments, when the transition and coupling grating regions are two-dimensional surface relief gratings, the periods of the transition and coupling gratings in both directions are Λ3, and the included angle is α. The linewidth of the visible light laser satisfies the following formula:

[0021]

[0022] Where ε is the angular resolution of the human eye, θ is the angle between the optomechanical coupling direction and the normal to the surface of at least one optical waveguide lens, and λ is the wavelength of the transmitted image light.

[0023] According to some embodiments, the optical engine emits RGB three-color light; at least one optical waveguide lens includes three optical waveguide lenses, each optical waveguide lens having a coupling period and a turning and coupling period corresponding to each color of light; the sum of the coupling grating vector and the turning and coupling grating vector is not zero, wherein the coupling angle between the optical engine and the three optical waveguide lenses is the same.

[0024] According to some embodiments, the optical engine emits RGB three-color light, including:

[0025] The linewidth of blue light ranges from 0 to 2 nm, with an optional range of 0 to 0.5 nm.

[0026] The linewidth of green light ranges from 0 to 2.3 nm, with an optional range of 0 to 0.5 nm.

[0027] The linewidth of red light ranges from 0 to 2.7 nm, with an optional range of 0 to 0.5 nm.

[0028] According to some embodiments, the thickness of the optical waveguide substrate is 0.3 mm to 2.5 mm, and the refractive index is 1.4 to 2.2.

[0029] According to some embodiments, the optical waveguide substrate is transparent and has a fixed thickness, has two opposing optical planes, and the material includes glass or quartz.

[0030] According to the technical solution of this application, a planar optical waveguide lens with a non-zero grating vector sum is proposed, which ensures that the optical engine and the optical waveguide lens can still coincide with the central field of view of the human eye even when they are not perpendicularly coupled. The combination of a visible light laser and a waveguide with a non-zero grating vector sum greatly enhances the freedom of design for the structure of the optical engine and the optical waveguide lens.

[0031] It should be understood that the above general description and the following detailed description are merely exemplary and do not limit this application. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings, without exceeding the scope of protection claimed by this application.

[0033] Figure 1 A side view of an augmented reality display device according to an exemplary embodiment is shown.

[0034] Figure 2 A side view showing the optical mechanism and optical waveguide lens coupled in a vertical manner according to an exemplary embodiment.

[0035] Figure 3 This diagram illustrates a scenario where the sum of the coupled-in grating vector and the inflection point and the coupled-out grating vector is zero, according to an exemplary embodiment.

[0036] Figure 4 A side view showing the optomechanical and waveguide mirrors coupled in a non-perpendicular manner according to an exemplary embodiment.

[0037] Figure 5 This diagram illustrates a non-zero sum of the coupled-in grating vector and the inflection point and the coupled-out grating vector, according to an exemplary embodiment.

[0038] Figure 6 A side view showing the optomechanical and waveguide mirrors coupled in a non-perpendicular manner according to another exemplary embodiment.

[0039] Figure 7 The diagram shows the distribution of the light source of an optical engine in K-space according to an exemplary embodiment.

[0040] Figure 8 The diagram shows the distribution of the light source of the optomechanism after coupling into the K-space according to an exemplary embodiment.

[0041] Figure 9 The diagram shows the distribution of the light source of an optomechanism after coupling out according to an exemplary embodiment in K-space.

[0042] Figure 10 A three-dimensional schematic diagram of a transition and coupling grating as a two-dimensional grating according to an exemplary embodiment is shown.

[0043] Figure 11 A distribution diagram of the light source of an optical engine according to another exemplary embodiment in K-space is shown.

[0044] Figure 12 The diagram shows the distribution of the light source of the optomechanism after coupling into the K-space according to an exemplary embodiment.

[0045] Figure 13 The diagram shows the distribution of the light source of an optomechanism after being coupled out of a two-dimensional grating in K-space according to an exemplary embodiment.

[0046] Figure 14 A side view showing the optomechanic and RGB three-layer waveguide lens coupled in a non-perpendicular manner according to an example embodiment.

[0047] Figure 15 A side view showing the optomechanic coupled to the RGB three-layer waveguide lens in a non-perpendicular manner according to another example embodiment. Detailed Implementation

[0048] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, they are provided so that this application will be thorough and complete, and will fully convey the concept of the exemplary embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar parts, and therefore repeated descriptions of them will be omitted.

[0049] The described features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. Numerous specific details are provided in the following description to give a full understanding of embodiments of this disclosure. However, those skilled in the art will recognize that the technical solutions of this disclosure can be practiced without one or more of these specific details, or other methods, components, materials, devices, etc. In these cases, well-known structures, methods, devices, implementation steps, materials, or operations will not be shown or described in detail.

[0050] Furthermore, the terms “comprising” and “having”, and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the steps or units listed, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to such process, method, product, or apparatus.

[0051] The terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion.

[0052] Figure 1 A side view of an augmented reality display device according to an exemplary embodiment is shown.

[0053] There are currently 100 known augmented reality display devices, such as Figure 1 As shown, it includes an optical waveguide lens 101 and an optomechanical system 102. The optical waveguide lens 101 includes an optical waveguide substrate 1011, a coupling grating region 1012, and a turning and coupling grating region 1013. The coupling grating region is a one-dimensional surface relief grating. The turning and coupling grating region can be a one-dimensional surface relief grating or a two-dimensional surface relief grating.

[0054] According to the embodiment, after the image light from the optomechanical system 102 passes through the coupling grating region 1012, the diffracted light is transmitted by total internal reflection by the optical waveguide substrate 1011 to the turning and coupling grating region 1013, and is finally diffracted to the human eye 103. The sum of the coupling grating vector and the turning and coupling grating vector is not zero, and the coupling angle of the optomechanical system and each layer of optical waveguide lens is the same.

[0055] The optical waveguide substrate 1011 is transparent to visible light and has two opposing optical planes for total internal reflection transmission of image light. Optionally, the optical waveguide substrate 1011 has a thickness of 0.3 mm to 2.5 mm and a refractive index of 1.4 to 2.2 (currently, the refractive index of commercially available optical materials is generally within this range), and the material of the optical waveguide substrate includes glass or quartz.

[0056] Based on known theoretical characteristics, the waveguide substrate 1011 in this application is preferably thin and light with a high refractive index. Utilizing the principle of total internal reflection, light entering the optical engine under certain conditions can undergo total internal reflection, thus achieving the task of transporting light from the optical engine to in front of the human eye.

[0057] The known augmented reality display device 100 achieves the ability to move a large optical engine around the eyes to the side, such as the side or forehead, without obstructing the line of sight, and then bring light to the front of the eyes through a transmission medium such as a light waveguide lens 101.

[0058] Another significant advantage is that it can increase the range of eye movement (the range of x and y movement of the eyes around the center point of the system while wearing glasses, allowing for clear image viewing). This increased range of eye movement makes it easier to adapt products to all groups of people.

[0059] Of course, there are also some drawbacks. For example, the optical efficiency is relatively low, and for diffractive waveguides, there will be some rainbow phenomenon caused by dispersion and uneven color, resulting in alternating bright and dark light. Usually, in order to make the central field of view of the optical engine coincide with the central field of view of the human eye, the optical engine needs to be perpendicularly coupled to the optical waveguide mirror, which limits the freedom of structural design.

[0060] Figure 2 A side view showing the optical mechanism and optical waveguide lens coupled in a vertical manner according to an exemplary embodiment.

[0061] like Figure 2 As shown, the optical engine and waveguide lens are typically coupled perpendicularly. This ensures that the central field of view of the optical engine corresponds to the central field of view observed by the human eye. However, this perpendicular coupling restricts the flexibility of the optical engine and waveguide lens layout, which is detrimental to the structural design of AR glasses. If the optical engine and waveguide lens are coupled non-perpendicularly, the human eye and the waveguide lens will not be parallel in order to make the central field of view observed by the human eye coincide with the central field of view of the optical engine (see...). Figure 4 This will affect the user's viewing experience.

[0062] Figure 3 This diagram illustrates the sum of the coupled-in grating vector and the inflection point and the coupled-out grating vector according to an exemplary embodiment.

[0063] like Figure 3 As shown, generally speaking, in the design of optical waveguide lenses, the sum of the coupled-in grating vector and the inflection point vector and the coupled-out grating vector is 0, that is, the coupled-in grating vector... Transformation grating vector Coupled grating vector

[0064] According to the embodiment, when the turning and coupling grating area is a one-dimensional surface relief grating, the corresponding grating vector refers to the vector sum of the turning grating vector and the coupling grating vector; when the turning and coupling grating area is a two-dimensional surface relief grating, the corresponding grating vector refers to the grating vector of the two-dimensional surface relief grating.

[0065] Commonly used relief gratings mainly include one-dimensional gratings, such as tilted gratings, trapezoidal gratings, blazed gratings, and rectangular grating structures. Two-dimensional gratings, such as the hexagonal cylindrical grating structure commonly used in waveguides, also exist. The feature dimensions of these grating structures are all in the nanometer range. Therefore, the current main approaches to relief grating waveguides are: relief grating waveguide schemes based on one-dimensional gratings, as shown in the schematic diagram. Figure 1 As shown, it is divided into coupling in, turning and coupling out regions. All three regions use a one-dimensional grating, and the turning and coupling out regions are extended in one direction respectively.

[0066] The relief grating waveguide scheme based on a two-dimensional grating is divided into coupling-in and coupling-out regions. The classic structure of the coupling-in region is a one-dimensional grating, while the structure of the coupling-out region is a two-dimensional grating (not shown in the figure). Multiple orders of the two-dimensional grating structure are used to simultaneously ensure beam coupling and multi-directional propagation. The K-domain diagram of the two-dimensional grating waveguide is calculated through simulation (see...). Figures 11 to 13 The inner ring represents the total internal reflection condition of light in the waveguide, and the outer ring represents the maximum K value that the waveguide material can achieve. The coupling grating shifts the K value of the light beam to the annular region, so that the light beam satisfies the condition of total internal reflection propagation in the waveguide. The coupling grating shifts the K value of part of the light beam from the annular region to the inner ring region, so that the light beam is coupled out to the human eye.

[0067] At this point, in the case of transmission, the light rays coupled out to the human eye are in the same direction as the light rays coupled into the optical waveguide lens by the optomechanic; in the case of reflection, the light rays coupled out to the human eye and the light rays coupled into the optical waveguide lens by the optomechanic are mirror-symmetrical about the normal to the surface of the optical waveguide lens.

[0068] Figure 5 This diagram illustrates a non-zero sum of the coupled-in grating vector and the inflection point and the coupled-out grating vector, according to an exemplary embodiment.

[0069] like Figure 5 As shown, when the sum of the grating vectors of the coupled-in grating and the inflection grating and the coupled-out grating is not zero, that is, the coupled-in grating vector... Transformation grating vector Coupled grating vector According to existing theory, since the grating period is inversely proportional to the grating vector magnitude, the technical solution of this application calculates the coupling grating period and the transition and coupling grating periods of different periods under the condition of total internal reflection. This allows the human eye to observe the central field of view of the optical engine from the angle parallel to the optical waveguide mirror when the optical engine and the optical waveguide mirror are not perpendicularly coupled (see [link]). Figure 6 ).

[0070] Since the grating vector sum of the optical waveguide lens is not zero, chromatic dispersion will occur. However, using a narrow linewidth light source can prevent the human eye from observing the dispersion phenomenon. The linewidth that does not affect the imaging quality of the optical waveguide lens can be obtained as described below.

[0071] Figure 7 The diagram shows the distribution of the light source of an optical engine in K-space according to an exemplary embodiment.

[0072] Figure 8 The diagram shows the distribution of the light source of the optomechanism after coupling into the K-space according to an exemplary embodiment.

[0073] Figure 9The diagram shows the distribution of the light source of an optomechanism after coupling out according to an exemplary embodiment in K-space.

[0074] See Figures 7 to 9 The distribution of the light source of the optical engine in K-space (see Figure 7 According to the embodiment, when the turning and coupling gratings are one-dimensional surface relief gratings, the angle θ between the optomechanical coupling and the normal to the surface of the optical waveguide lens is set to 10°, and the center wavelength of the light source is λ. c =460nm, half-width at half-maximum wavelength λ1, field of view of the optomechanical system is 40°, refractive index of the waveguide mirror is n = 1.7216, the period of the coupling grating is set to Λ1, and its size is preferably such that it is distributed exactly in the ring. The distribution of the light output from the optomechanical system in K-space after passing through the coupled one-dimensional surface relief grating is as follows: Figure 8 As shown.

[0075] After passing through a one-dimensional surface relief transition and coupling grating, with the period of the transition and coupling grating set to adjust the coupling center field of view to be vertically output from the optical waveguide mirror, the distribution in K-space after passing through the one-dimensional surface relief transition and coupling grating is as follows: Figure 9 As shown. Because the grating vector sum of the optical waveguide mirror is not zero, dispersion of the optical waveguide mirror is unavoidable (compare). Figure 7 (Distribution).

[0076] According to an embodiment, a visible light laser can be used as the light source, and its narrow linewidth characteristic can be used to limit the dispersion of the optical waveguide mirror, making the dispersion phenomenon invisible to the human eye. The required linewidth of the visible light laser can be calculated using the following formula. Where ε is the angular resolution of the human eye, specifically, it can be 1′, and for AR glasses, 2′ is also acceptable. It is known that the angle between the optomechanical coupling and the normal to the surface of the optical waveguide lens is θ = 10°. For the above embodiment, under the condition that the human eye resolution is 1′, the linewidth of the visible light laser can be calculated to be 0.76nm, where Λ1 = 460nm and Λ2 = 384.7nm.

[0077] When the light source emits RGB three-color light, the method for calculating the linewidth of the visible laser is the same, which will not be repeated here and does not limit this application.

[0078] Specifically, light emitted from an object passes through the pupil of the human eye and is refracted by the eye's refractive system to form an image on the retina. Since the focal length of the human eye is only about 20mm, the image on the retina is a Fraunhofer circular aperture diffraction pattern. The pupil is essentially a circular aperture, its diameter of which is adjusted by the iris within the range of 2mm-8mm. Under normal lighting conditions, the pupil diameter is approximately 3mm. The wavelength of green light to which the human eye is most sensitive is 550nm, and the minimum resolvable angle of the human eye is 1′.

[0079] Specifically, a 40° field of view for an optical instrument can be understood as the angle between the two edges of the lens (with the lens as the vertex) representing the maximum range through which the image of the target object can pass through the lens. The size of the field of view determines the field of view of the optical instrument; the larger the field of view, the wider the field of view, but the lower the optical magnification. In simpler terms, objects exceeding this angle will not be captured by the lens.

[0080] Figure 10 A three-dimensional schematic diagram of a transition and coupling grating as a two-dimensional grating according to an exemplary embodiment is shown.

[0081] like Figure 10 According to the embodiment, the optical waveguide substrate 1011 of the optical waveguide lens 101 has a one-dimensional surface relief grating in the coupling grating region 1012. The turning and coupling grating region 1013 is a two-dimensional surface relief grating, which is composed of two one-dimensional surface relief gratings and the period of the two-dimensional grating in both directions is Λ3, with an included angle of α.

[0082] Figure 11 A distribution diagram of the light source of an optical engine according to another exemplary embodiment in K-space is shown.

[0083] Figure 12 The diagram shows the distribution of the light source of the optomechanism after coupling in K-space according to another exemplary embodiment.

[0084] Figure 13 The diagram shows the distribution of the light source of an optomechanism after being coupled out of a two-dimensional grating in K-space according to an exemplary embodiment.

[0085] See Figures 11 to 13 According to the embodiment, when the turning and coupling gratings are two-dimensional gratings, the angle θ between the optomechanical coupling and the normal to the surface of the optical waveguide lens is set to 10°, and the center wavelength of the light source is λ. c =460nm, half-width at half maximum (FWHM) wavelength is λ1, field of view of the optical engine is 40°, refractive index of the optical waveguide lens is n=1.7216, distribution of the optical engine in K space at the center wavelength.

[0086] The period of the coupling grating is set to Λ1, and its size is preferably such that it is distributed exactly in the ring. The distribution of the light output from the optomechanical engine in K-space after passing through the coupling grating is as follows: Figure 12 As shown. The light source is coupled out through a two-dimensional grating. The period of the two-dimensional grating in both directions is Λ3, and the included angle is α, so that the center field of view of the coupled-out light source is perpendicular to the output of the waveguide mirror, as shown. Figure 13 As shown. The required linewidth of the visible light laser can be calculated using the following formula: Where ε is the angular resolution of the human eye, specifically, it can be taken as 1′, and for AR glasses, 2′ is also acceptable. It is known that the angle θ between the optomechanical coupling and the normal to the surface of the waveguide lens is 10°. The linewidth of the visible light laser can then be calculated to be 0.76 nm. Therefore, the required linewidth and inflection point of the visible light laser are independent of whether the output grating is one-dimensional or two-dimensional.

[0087] When the light source emits RGB three-color light, the method for calculating the linewidth of the visible laser is the same, which will not be elaborated here and should not be used as a limitation of this application.

[0088] Since the sum of the grating vectors of the optical waveguide lens is not zero, there will be a dispersion problem. The K-space distribution map obtained through experiments, and the linewidth of the visible light laser calculated based on known set conditions and parameters, make the dispersion phenomenon invisible to the human eye.

[0089] The following will further illustrate this with reference to the embodiments.

[0090] According to an embodiment, three RGB waveguide lenses are stacked vertically on the waveguide surface in the order of blue, green, and red light filters (not shown in the figure). Optionally, cutoff filters can be placed between each waveguide lens layer to prevent light of the cutoff wavelength from passing through. Specifically, a blue cutoff filter is placed between the blue and green light filters to prevent blue light from passing through; correspondingly, a green cutoff filter is placed between the green and red light filters to prevent green light from passing through. The angle between the surfaces of the three waveguide lenses and the vertical direction is γ, and the angle between the optomechanical coupling direction and the normal to the surface of each waveguide lens layer is θ. The waveguide lens substrate material with a refractive index of n = 1.72 is selected, and the dominant wavelengths of the optomechanical system are 460 nm, 530 nm, and 620 nm. Currently, the minimum linewidth of optomechanical visible light lasers is generally 0.5nm. To meet the requirement of a 0.5nm linewidth for optomechanical visible light lasers, the tilt angle of the optomechanical system can be in the range of 0-15°. The tilt angle should not be too large, otherwise it will cause image distortion.

[0091] The embodiments described below, which include the above conditions, are not intended to limit this application.

[0092] Figure 14 A side view showing an optomechanical system coupled to at least one layer of optical waveguide lens in a non-perpendicular manner according to an example embodiment.

[0093] like Figure 14As shown, in this embodiment, the angle θ between the optical engine and the surface normal of the optical waveguide lens is 10°, and the angle γ between the surface of the optical waveguide lens and the vertical direction is 5°. Therefore, θ + γ should not exceed 20°. If the linewidth of the visible laser is further reduced, this restriction can be relaxed. For different wavelengths of light, the coupling period and the turning and coupling periods of the grating are different. Generally, different optical waveguide lenses are used to transmit light of different wavelengths. When the light emitted by the optical engine consists of RGB colors, three layers of optical waveguide lenses serve as the transmission medium. Each layer of optical waveguide lens has its own coupling period and turning and coupling periods corresponding to each color of light. In this embodiment, blue light with λ = 460nm is used as an example; the same logic applies to red and green light, which will not be elaborated here. To ensure that the coupled light rays can all satisfy total internal reflection transmission within the optical waveguide lens substrate, the coupling grating period Λ1 = 460nm is set. The turning and coupling gratings ensure that the light rays in the central field of view of the optical engine are coupled out of the central field of view of the human eye after transmission through the optical waveguide lens, which must satisfy... in With clockwise rotation of the vertical centerline defined as positive, γ can be negative, meaning the angle γ between the optical waveguide lens 101 and the vertical centerline rotates counterclockwise. In other words, the optical waveguide lens tilts towards the eye. Therefore, the period Λ2 of the bend and coupling grating in this embodiment is 364.9 nm.

[0094] Figure 15 A side view showing the optomechanic coupled to a three-layer RGB waveguide lens in a non-perpendicular manner according to another example embodiment.

[0095] like Figure 15 As shown, in this embodiment, the angle θ between the optical engine and the normal to the waveguide surface is 10°, and the angle γ between the surface of the vertically set waveguide lens and the vertical direction is 0°. In this case, θ + γ should not exceed 20°. If the linewidth of the visible laser is further reduced, this restriction can be relaxed. For different wavelengths of light, the coupling period and the turning and coupling periods of the grating are different. Generally, different waveguide lenses are used to transmit light of different wavelengths. When the light emitted by the optical engine consists of RGB colors, three layers of waveguide lenses are used as the transmission medium. Each layer of waveguide lens has its own coupling period and turning and coupling periods corresponding to each color of light. In this embodiment, blue light with λ = 460nm is used as an example; the same logic applies to red and green light. To ensure that the coupled light rays can all satisfy total internal reflection transmission within the waveguide lens substrate, the coupling grating period Λ1 = 460nm is set. The turning and coupling gratings ensure that the light rays in the central field of view of the optical engine are coupled out of the central field of view of the human eye after transmission through the waveguide lens, which must satisfy... in The corresponding transition and coupling grating period Λ2 = 391.94 nm.

[0096] Continue to refer to Figure 15In this embodiment, the angle θ between the optical engine and the normal to the waveguide surface is 10°, and the angle γ between the surface of the waveguide lens and the vertical direction is 0° when the waveguide is vertically set. In this case, θ + γ should not exceed 20°. If the linewidth of the visible laser is further reduced, this restriction can be relaxed. For different wavelengths of light, the coupling period and turning / exit periods of the grating are different. Generally, different waveguide lenses are used to transmit light of different wavelengths. When the light emitted by the optical engine consists of RGB colors, three layers of waveguide lenses serve as the transmission medium. Each layer of waveguide lens has its own coupling period and turning / exit period corresponding to each color of light. In this embodiment, blue light with λ = 460nm is used as an example; the same logic applies to red and green light, which will not be elaborated here. To ensure that all coupled light rays can be transmitted through total internal reflection within the waveguide lens substrate, a coupling grating period of Λ1 = 460 nm is set. The deflection and coupling gratings ensure that light rays from the central field of view of the optomechanical system are coupled out of the central field of view of the human eye after being transmitted through the waveguide lens. The corresponding deflection and coupling gratings are two-dimensional gratings, which are composed of two one-dimensional gratings, each with a period of Λ3 = 337 nm and an angle of 52° between them.

[0097] Continue to refer to Figure 15 In this embodiment, the angle θ between the optical engine and the normal to the waveguide surface is 15°, the waveguide is vertically positioned, and the angle γ between the surface of the optical waveguide lens and the vertical direction is 0°. Therefore, θ + γ should not exceed 20°. This restriction can be relaxed if the visible laser linewidth is further reduced. For different wavelengths of light, the coupling period and turning / exit periods of the grating are different. Generally, different optical waveguide lenses are used to transmit different wavelengths of light. When the light emitted by the optical engine consists of RGB colors, three layers of optical waveguide lenses serve as the transmission medium. Each layer of optical waveguide lens has its own coupling period and turning / exit periods corresponding to each color of light. In this embodiment, blue light with λ = 460nm is used as an example; the same logic applies to red and green light, which will not be elaborated here. To ensure that the coupled light rays can all satisfy total internal reflection transmission within the optical waveguide lens substrate, the coupling grating period Λ1 = 500nm is set. The turning and exit gratings ensure that the light rays in the central field of view of the optical engine are coupled out of the central field of view of the human eye after transmission through the optical waveguide lens, satisfying the following conditions. in The corresponding transition and coupling grating period Λ2 = 390.2 nm.

[0098] Continue to refer to Figure 15According to the embodiment, the angle between the optical engine and the normal to the waveguide surface is θ = 3.83°, and the angle between the surface of the waveguide lens and the vertical direction is γ = 0° when the waveguide is vertically set. At this time, θ + γ should not exceed 20°. If the linewidth of the visible light laser is further reduced, this restriction can be relaxed. For light of different wavelengths, the coupling period and the turning and coupling periods of the grating are different. Generally, different optical waveguide lenses are used to transmit light of different wavelengths. When the light emitted by the optical engine consists of RGB colors, three layers of optical waveguide lenses are used as the transmission medium. Each layer of optical waveguide lens has its own coupling period and turning and coupling periods corresponding to each color of light. In this embodiment, taking blue light with λ = 460nm as an example, in order to ensure that the coupled light rays can be transmitted in the optical waveguide lens substrate to meet total internal reflection, the coupling grating period Λ1 = 400nm is set. The turning and coupling gratings ensure that the light rays in the central field of view of the optical engine are coupled out of the central field of view of the human eye after being transmitted through the optical waveguide lenses. The corresponding turning and coupling grating Λ2 = 378nm is calculated according to the required laser linewidth. Given δλ = 2nm, similarly, when the green light wavelength λ = 530nm, in order to ensure that the coupled light rays can all satisfy total internal reflection transmission in the optical waveguide lens substrate, the coupling grating period Λ1 = 440nm is set, and the turning and coupling grating periods Λ2 = 416.9nm are set. Then, the corresponding laser linewidth is calculated to be δλ = 2.3nm.

[0099] Similarly, when the wavelength of the red light is λ = 620nm, in order to ensure that the coupled light rays can all satisfy total internal reflection transmission in the optical waveguide lens substrate, the period of the coupling grating is set to Λ1 = 510nm, and the period of the turning and coupling gratings is set to Λ2 = 483.3nm. Then the corresponding laser linewidth is calculated to be δλ = 2.7nm.

[0100] Table 1 shows that, according to the embodiment, the laser linewidth ranges from 0 to 2 nm with different included angles and grating periods for blue light λ = 460 nm, and the selectable range is less than or equal to 0.5 nm.

[0101]

[0102] The statistical data for red and green light are as described above and will not be repeated here.

[0103] Through the technical solutions of the embodiments of this application, this application provides an augmented reality display device, and addresses the chromatic dispersion problem existing in optical waveguide lenses by using a narrow linewidth light source, which makes the chromatic dispersion phenomenon invisible to the human eye. Detailed and feasible conditions for satisfying this problem are explained in the embodiments. Through the technical solutions of this application, the optical engine and optical waveguide lenses can still ensure that the central field of view of the optical engine coincides with the central field of view of the human eye even when they are not perpendicularly coupled, greatly improving the freedom of design for the optical engine and optical waveguide lens structures.

[0104] The embodiments of this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the embodiments above are only for the purpose of helping to understand the method and core ideas of this application. Furthermore, any changes or modifications made by those skilled in the art based on the ideas of this application, and on the specific implementation methods and application scope of this application, are all within the scope of protection of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. An augmented reality display device, characterized in that, include: Optical engines are used to emit light for images; At least one optical waveguide lens is provided for coupling in, deflecting, and coupling out image light emitted by the optomechanical system. The at least one optical waveguide lens includes an input grating region, an optical waveguide substrate, and a deflecting and coupling out grating region. in, The coupling grating region is disposed on the first optical surface of the optical waveguide substrate and receives the image light emitted by the optomechanical system. The optical waveguide substrate is used to transmit image light through total internal reflection; The turning and coupling grating region is disposed on the first optical surface of the optical waveguide substrate, and receives the total internal reflection light transmitted by the optical waveguide substrate and couples it out. The sum of the input grating vector and the inflection vector and the output grating vector is not zero. Wherein, the optomechanic has the same coupling angle with at least one layer of optical waveguide lens; The light source of the optical engine transmits image light including visible laser, and the narrow linewidth characteristic of the light source limits the dispersion of the optical waveguide lens; The linewidth of the visible laser, the period of the input grating, and the periods of the inflection and output gratings satisfy the following formula: ， in, The angle between the optomechanical coupling direction and the surface normal of the at least one optical waveguide lens, which is the angular resolution of the human eye. Coupled grating period The transition and coupling grating period The visible laser linewidth .

2. The display device according to claim 1, characterized in that, At least one optical waveguide lens corresponds to an image light of one color.

3. The display device according to claim 1, characterized in that, The transition and coupling grating region includes a one-dimensional surface relief grating or a two-dimensional surface relief grating.

4. The display device according to claim 3, characterized in that, When the transition and coupling grating regions are two-dimensional surface relief gratings, the periods of the transition and coupling gratings in both directions are both... The included angle is The linewidth of the visible laser satisfies the following formula: in, The angle between the optomechanical coupling direction and the surface normal of the at least one optical waveguide lens, which is the angular resolution of the human eye. The wavelength of the light used to transmit the image is .

5. The display device according to claim 1, characterized in that, The optical engine emits RGB three-color light; The at least one optical waveguide lens includes three optical waveguide lenses, each of which has a coupling period and a turning and coupling period corresponding to each color of light. The sum of the coupled-in grating vector and the inflection vector and the coupled-out grating vector is not zero. The coupling angles of the optical engine and the three-layer optical waveguide lens are all the same.

6. The display device according to claim 5, characterized in that, The optical engine emits RGB three-color light, including: The linewidth range of the RGB three-color light emitted by the optical engine is between 0 and 2.7 nm.

7. The display device according to claim 6, characterized in that, The linewidth range of the RGB three-color light emitted by the optical engine is between 0 and 0.5 nm.

8. The display device according to claim 1, characterized in that, The optical waveguide substrate has a thickness of 0.3 mm to 2.5 mm and a refractive index of 1.4 to 2.

2.

9. The display device according to claim 8, characterized in that, The optical waveguide substrate is transparent and has a fixed thickness, has two opposing optical planes, and is made of materials including glass or quartz.

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