Optical system for augmented reality head-up display with improved visual ergonomics

Abstract

The disclosed embodiments relate to an optical system for an augmented reality (AR) head-up display (HUD) device. The implementation of the disclosed optical system in an AR HUD device can improve visual ergonomics by providing an enhanced stereoscopic depth of field (SDoF). The SDoF is created by forming a suitable shape and spatial direction of a virtual image surface (VIS), with the convex surface directed towards the user or observer. When the optical system of the AR HUD device is implemented in a vehicle, the driving comfort and safety can be improved through improved visual ergonomics.

Description

Technical Field

[0001] Embodiments discussed herein generally relate to optics, heads-up displays (HUDs), and augmented reality (AR) systems, and more particularly to configurations and arrangements of optical elements and devices to enhance and / or improve visual ergonomics by improving depth of field. Background Art

[0002] A head-up display (HUD) is a transparent display that presents information without requiring the viewer to avert their gaze. A typical HUD consists of a combiner, a light projection device (called a "projector" or "projection unit"), and a video / image generating computer device. The combiner is usually a piece of glass located directly in front of the viewer that redirects the projected image from the projector so that both the real world environment and the projected virtual image are seen simultaneously. The projector is usually an optical unit that includes lenses or mirrors with a cathode ray tube, a light emitting diode (LED) display, or a liquid crystal display (LCD) that generates the image. However, these classic HUDs often produce optical aberrations and require multiple mirrors or lenses to correct for these aberrations. A holographic HUD (hHUD) usually consists of a laser projector and a holographic optical element (HOE) as a combiner. Some hHUDs place the HOE inside the display screen, such as the windshield or windshield of a car or airplane.

[0003] When implemented in vehicles such as cars or airplanes, HUDs can reduce the duration and frequency with which vehicle operators look away from the windshield. However, HUD-based augmented reality (AR) applications are somewhat limited due to the narrow field of view and fixed virtual image distance. These limitations make it difficult to match or otherwise project virtual images to related real objects. Summary of the invention

[0004] The present disclosure describes various configurations and arrangements of optical elements for augmented reality (AR) systems, such as heads-up displays (HUDs) and / or holographic HUDs (hHUDs). Embodiments of the present disclosure improve visual ergonomics by providing SDoF. This stereoscopic depth of field (SDoF) is created through the shape and orientation of a virtual image surface (VIS) in the AR system. The configurations and arrangements of various optical elements of the AR system, such as described below, provide a shape and orientation of the VIS, which can produce the SDoF. When such an AR system is implemented as a HUD or hHUD (collectively referred to as a "(h)HUD") in a vehicle, the improved visual ergonomics can provide improved driving comfort and safety.

[0005] The first conventional HUD, such as that discussed in U.S. Pat. No. 10,814,723, achieves SDoF by tilting the VIS in the vertical field of view (FoV) direction, and thus, virtual objects located in the lower region of the FoV appear closer than virtual objects located in the upper region of the FoV. In other words, the first conventional HUD provides an SDoF in the vertical FoV direction that tends to be significantly narrower (at least twice) than the horizontal FoV. In addition, the narrow vertical FoV limits the provision of sufficient SDoF for significantly improved visual ergonomics. In addition, the difficulty of SDoF in the first conventional HUD is significantly improved, while keeping the available size of the virtual object unchanged, but not exceeding the stereo threshold (i.e., the observer will not perceive it as tilted), which is caused by the limitation of the vertical size of the FoV.

[0006] A second conventional HUD, such as that discussed in Japanese application No. 2017227681, can achieve SDoF by forming a VIS with a curved shape. However, the convex side of the curved shape is away from the observer. In the second conventional HUD, virtual objects in the central area of ​​the FoV appear farther away than virtual objects on the side areas of the FoV. This limitation of visual ergonomics leads to defects in driving comfort and driving safety, and is caused by the curved VIS spatial orientation described above. Therefore, virtual interface elements that appear on the side of the VIS and display virtual objects of driving direction (e.g., navigation arrows or other graphical elements / objects) are inconsistent with the natural perception of the real driving direction seen by the observer. In addition, there is a risk that the central part of the VIS will either intersect with the moving vehicle in front of the vehicle or be located in front of the moving vehicle in front of the vehicle, which will have a negative impact on the comfort of the vehicle's visual perception.

[0007] In addition, the VIS spatial orientation of the second conventional HUD mentioned above provides an inverted perspective for virtual object representation. This means that virtual objects farther from the observer will have larger angular sizes than virtual objects closer to the observer, which is inconsistent with the natural perception of three-dimensional (3D) space. In addition, it is difficult to increase the SDoF of the second conventional HUD because of the limitation of the FoV size due to the inherent properties of the optical system. Here, the increase in FoV size also affects the system size.

[0008] The main disadvantage of conventional HUDs (such as those discussed above) is limited visual ergonomics. Limited visual ergonomics is related to the insufficient value provided by SDoF. The ability to increase SDoF in conventional HUDs is limited by the size of the FoV and the available size of virtual objects that are not perceived as tilted. Limited visual ergonomics leads to disadvantages in driving comfort and driving safety. These disadvantages are caused by the shape of the virtual image with its convex side facing away from the observer.

[0009] Compared to conventional HUDs, the optical systems / devices discussed herein can improve visual ergonomics. In particular, compared to conventional HUDs, the optical systems / devices discussed herein provide a larger SDoF. This larger SDoF is provided by the proper shape and spatial orientation of the VIS, which can align displayed virtual objects (e.g., objects / images generated by the HUD system) with real objects (e.g., objects seen through the vehicle windshield). The correct shape and spatial orientation of the VIS also reduce the likelihood that the center area of ​​the VIS will intersect with a vehicle traveling in front of the vehicle. In these ways, the optical systems / devices discussed herein improve comfort and safety when operating a vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The embodiments will be readily understood by the detailed description below together with the accompanying drawings and claims. The embodiments are described by way of example and not limitation in the drawings, in which:

[0011] Figure 1a Depicted is a vertical cross-sectional view of an example augmented reality (AR) heads-up display (HUD) system in accordance with various embodiments. Figure 1b Depiction Figure 1a Horizontal cross-section of an AR HUD system. Figure 2 Another example ARHUD system is depicted in accordance with various embodiments.

[0012] Figure 3 Depicts the HUD's field of view (FoV) and stereo depth of field (SDoF), showing an eye box relative to the virtual image. Figure 4 Depicted are vertical and horizontal cross sections of a virtual image surface (VIS) according to various embodiments. Figure 5 Depiction Figure 4 Example implementation of vertical and horizontal sections of VIS.

[0013] Figure 6 Depicting a comparison between AR HUD optical systems. Figure 7 Drawing display Figure 6 A chart comparing the droop of AR HUD optical systems. Figure 8 and 9 Example VIS shapes for different driving scenarios are shown. Fig.10 Depicted are example segmentation rules for horizontal FoV for natural viewing angles according to various embodiments.

[0014] Fig.11 , 12 and 13 to describe the various characteristics of (SDoF). Fig.14 Depicting the limitations of the vertical field of view size of a typical AR HUD. Fig.15A graph is depicted showing the dependence of the volume of a typical AR HUD on the light magnification of the combiner for different distances of the virtual image. DETAILED DESCRIPTION

[0015] A first implementation includes an optical system of an AR HUD configured to generate a three-dimensional (3D) virtual image. The optical system includes a picture generation unit (PGU), a combiner, and a corrector disposed between the PGU and the combiner. The corrector is implemented as a combination of optical surfaces. The optical surfaces include refractive surfaces, reflective surfaces, or both refractive surfaces and reflective surfaces. The result of the interaction of the PGU, the corrector, and the combiner forms a curved VIS. To improve the visual ergonomics (e.g., driving comfort and safety) of the optical system by aligning one or more real images with one or more displayed virtual images and increasing the SDoF, the combiner is implemented as a holographic optical element with a positive lens, and the corrector includes at least one rotationally asymmetric optical surface for monotonically increasing the optical path length of light propagating from the PGU to the combiner along the horizontal FoV direction from the center of the FoV. In these ways, a cylindrical VIS can be formed, whose convex surface faces the observer and whose directrix is ​​a continuous curve, which is located along the horizontal FoV (HFoV) direction and / or extends in the HFoV direction. This can make virtual objects displayed in the central area of ​​the FoV appear closer than virtual objects displayed on the side parts of the FoV.

[0016] The second implementation includes the optical system of the first implementation, wherein the corrector creates an optical path length that increases monotonically from the center of the FoV in the direction horizontal to the FoV for light rays propagating from the PGU to the combiner to form the VIS, in such a way that the angle between any chief ray aimed in the direction horizontal to the FoV and the normal of the VIS increases as any chief ray becomes farther from the center of the FoV. This implementation can improve the visual perception quality by imaging virtual objects in the display FoV according to a natural viewing angle.

[0017] A third implementation includes the optical system of the first implementation and the second implementation, wherein the corrector comprises at least one prism, the prism comprising at least one reflective optical surface located between at least two refractive optical surfaces.

[0018] A fourth implementation includes the optical system of the first implementation, the second implementation, and the third implementation, wherein the one or more real images include real driving directions, and the one or more displayed virtual images include displayed virtual driving directions aligned with the real driving directions. As an example, the displayed virtual driving directions may be a route planning (TBT) pointer, a turn arrow, or other similar graphical elements of a TBT navigation service.

[0019] 1. Optical system for configuration and arrangement of augmented reality head-up display device

[0020] Figure 1a depicts a side view of a heads-up display (HUD) system 100 (or “HUD 100 ”), and Figure 1b Depicts a top view of a HUD 100 according to various embodiments. In particular, Figure 1a A vertical cross section showing the relative positions and interactions of the components of the HUD 100. The "vertical cross section" refers to the plane where the light rays forming the vertical FoV lie. In addition, Figure 1b A horizontal cross section showing the relative positions and interactions of the components of the HUD 100. The "horizontal cross section" refers to the plane where the rays forming the horizontal FoV lie.

[0021] In some implementations, the HUD 100 is or is part of an augmented reality (AR) system, and thus the HUD 100 may be referred to as an “AR HUD 100” or the like. The HUD 100 includes a picture generation unit (PGU) 101, a correction optical assembly 102 (also referred to as a “corrector 102”, a “correction optical element 102”, or the like), and a combiner 103. As examples, the PGU 101 may be implemented as a liquid crystal display (LCD) projector, an LCD with laser illumination, a light emitting diode (LED) projector, a laser diode projector, a digital light processing (DLP) projector, a projector based on a digital micromirror device (DMD), a liquid crystal on silicon (LCOS) with laser illumination, a micro-electromechanical system (MEMS) with laser scanning, a micro-opto-electromechanical system (MOEMS) laser scanner, and / or any other suitable device (or combination of devices). In some implementations, PGU 101 may also include a diffusing element 105 (also referred to as a "diffusing screen 105," a "diffusing surface 105," a "microlens array 105," and / or the like).

[0022] PGU 101 may also include a computer device and / or controller, or be communicatively coupled to a computer device and / or controller. The computer device / controller includes one or more electronic components that create / generate digital content to be displayed by HUD 100 and provide appropriate signals to PGU 101 for generating and projecting light representing the digital content to be displayed on combiner 103. Digital content (e.g., text, images, video, etc.) can be stored locally, streamed from one or more remote devices via communication circuits, and / or based on outputs from various sensors, electronic control units (ECUs), and / or actuators disposed in or on the vehicle. The content to be displayed may include, for example, safety messages (e.g., collision warnings, emergency warnings, pre-collision warnings, traffic warnings, etc.), SMS / MMS messages, navigation system information (e.g., maps, route arrows), movies, television programs, video game images, sensor information (e.g., speed, driving distance, etc.), and / or other similar information. The computer device and / or controller may be or may include any suitable processing element, such as one or more microcontrollers, microprocessors, application processors or central processing units (CPUs), graphics processing units (GPUs), ECUs, digital signal processors (DSPs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), system-on-chips (SoCs), special purpose processors specifically constructed and configured to control PGU 101, and / or combinations thereof. This element is now shown for simplicity of description and discussion, and so as not to obscure the disclosure of the described embodiments.

[0023] The combiner 103 in this example is a (semi-)transparent display surface located directly in front of the viewer 104, which redirects the projected virtual image from the PGU 101 in a way that allows the viewer 104 to see both the real world around them and the virtual image within the FoV, thereby facilitating AR. Typically, the size of the FoV is defined by the largest optical element of the HUD, which is typically a combiner element, such as the combiner 103. In some implementations, the combiner is a large reflective surface or other similar display surface. In some implementations, the combiner 103 includes a holographic optical element (HOE) in or on the surface of the combiner 103, which redirects the image / object. In these implementations, the HUD 100 may be referred to as a holographic HUD (hHUD), etc. In an example implementation, the combiner 103 is implemented as a HOE with an optical magnification in the range of 1.1-6.6 diopters and formed on a photopolymer substrate. The substrate may be placed on the inside of the windshield / windshield or integrated into the windshield / windshield during a ternary manufacturing process and / or some other manufacturing method. The combiner 103 and the HOE may be formed of any suitable material and / or material composite, such as, for example, one or more of glass, plastic, polymer, and / or other similar materials and / or variations. The HOE within or on the combiner 103 may have a specific arrangement that works with the other optical elements of the HUD 100 to display an image that appears far in front of the observer 104.

[0024] Corrector 102 (also referred to as "correction optical element 102" or "auxiliary optical element 102") works with combiner 103 to display a virtual image. Corrector 102 can be configured to correct aberrations caused by combiner 103. In various implementations, corrector 102 is disposed between PGU 101 and combiner 103. Corrector 102 can include one or more optical elements, such as, for example, lenses, prisms, mirrors, HOEs, prismatic lenses, and / or other optical elements and / or combinations thereof. In this example, corrector 102 includes a rotationally asymmetric surface 120 facing one side of combiner 103. Rotationally asymmetric surface 120 is a surface that does not have rotational symmetry. That is, as discussed in further detail below, rotationally asymmetric surface 120 enables corrector 102 to provide a monotonically increasing optical path length starting from the center of the FoV, thereby providing a curved VIS after the corrected light reaches combiner 103. The combiner 103 redirects the light into the eye box 104 , allowing the observer 104 to view virtual images displayed at different distances from the eye box 104 .

[0025] In one example, the corrector 102 is implemented as one or more refractive optical surfaces, one or more reflective optical surfaces, or some combination of at least one refractive optical surface and at least one reflective optical surface. Any of these optical surfaces may have a spherical, aspherical, toroidal, or free-form shape. The properties of the corrector 102 are based on the specific arrangement and configuration of the various optical elements of the HUD 100 within a specific environment (e.g., within a car cabin, an aircraft cockpit, etc.). For example, when the HUD 100 is configured or deployed within a car, the corrector 102 may have a first set of properties, and when the HUD 100 is configured or deployed within an aircraft cockpit, the corrector 102 may have a second set of properties. In another example, when the HUD 100 is configured or deployed in a first car of a first brand and model, the corrector 102 may have a first set of attributes, and when the HUD 100 is configured or deployed in a second car of a second brand and model, the corrector 102 may have a first (second) set of attributes. The set of attributes includes, for example, a surface type or pattern of the corrector 102, a shape formed by the surface of the corrector 102, a size of the corrector 102, a position of the corrector 102 relative to at least one other optical element, an orientation of the corrector 102 relative to at least one other optical element, a material or substance used to manufacture the corrector 102, and / or other attributes.

[0026] Figure 2 Another diagram depicting the relative positions and interactions of the elements of the HUD 100 according to various embodiments. Figure 2 , like numbered elements are the same as those discussed above. Figure 2 Also shown are some elements of corrective optics assembly 102, including optical elements 202 and 203.

[0027] Optical elements 202 and 203 may be formed into any type of three-dimensional shape, including at least one rotationally asymmetric optical surface and one or more additional optical surfaces, including flat or planar, spherical, aspherical, cylindrical, toroidal, biconical, freeform, and / or any suitable type of surface or combination thereof. The at least one rotationally asymmetric optical surface may have any type of surface design or geometry, such as those listed herein, as long as the surface type / design / geometry is not rotationally symmetric. In addition, in implementations where there is more than one additional optical surface, the additional optical surfaces may be the same or different than the other additional optical surfaces (e.g., a first additional optical surface may be a non-spherical surface and a second additional optical surface may be a freeform surface). Additionally or alternatively, one or more of the additional optical surfaces may have the same surface design / geometry as the at least one rotationally asymmetric optical surface. Furthermore, the individual surfaces of optical elements 202 and 203 may be spherical, aspherical, anamorphic, cylindrical, freeform, and / or any suitable type of surface or combination thereof. In implementations involving free-form surfaces, the free-form surfaces may be modeled and / or formed based on mathematical descriptions. Examples of such mathematical descriptions include radial basis functions, basis splines, non-uniform rational basis splines (NURBS), orthogonal polynomials (such as Zernike polynomials, Q-type polynomials, φ polynomials, etc.), non-orthogonal basis (e.g., XY XY polynomials), Chebyshev polynomials, Legendre polynomials, hybrid stitching representations, and / or combinations thereof.

[0028] In some implementations, optical element 202 is a telecentric lens and includes at least two cylindrical optical surfaces. Additionally or alternatively, optical element 202 has a concave surface / side pointing toward PGU 101. Additionally or alternatively, optical element 202 is formed in a rectangular polyhedron shape. Additionally or alternatively, optical element 203 is a prism or has a prism shape and includes at least two refractive optical surfaces and at least one reflective optical surface. In one example, at least two refractive optical surfaces are free-form refractive optical surfaces, and at least one reflective optical surface is a plane reflective optical surface. Individual free-form refractive optical surfaces may have the same surface shape / geometry as other free-form refractive optical surfaces, or may have a different surface design / geometry than other free-form refractive optical surfaces. Additionally or alternatively, at least one plane reflective optical surface is placed between at least two free-form refractive optical surfaces. Additionally or alternatively, at least one reflective optical surface of optical element 203 is located within optical element 203 and is directed at an angle relative to optical element 202 and / or combiner 013. Other features of the corrector 102 and other components of the HUD 100 are discussed in International Application No. PCT / IB2021 / 056977, which was filed on July 20, 2021 and is hereby incorporated by reference in its entirety into this application.

[0029] During operation, the HUD 100 is capable of forming full-color images, as described below. The PGU 101 projects a laser (or otherwise generates light) through the various optical elements of the corrector 102. In particular, the PGU 101 creates an intermediate image and projects it onto the diffuser 105. After being scattered at the diffuser 105, the light propagates through the corrector 102 and arrives at the combiner 103. At least one optical surface of the corrector 102 does not have rotational symmetry (e.g., rotationally asymmetric surface 120), which provides a monotonically increasing optical path length from the center of the FoV along the horizontal FoV direction for the light propagating from the PGU 101 to the combiner 103. The combiner 103 redirects the light into the eye box 104. The observer 104 perceives stereoscopic depth and sees virtual objects at different distances from the eye box 104, which complement the surrounding world (e.g., real images / objects in the FoV). Furthermore, the perception of virtual objects in the HUD's FoV corresponds to the natural viewing angle.

[0030] In addition to the various implementations discussed above, other implementations of HUD 100 are possible. Additionally or alternatively, some or all of the components of HUD 100 may be incorporated into a single housing or frame. For example, PGU 101 (or multiple PGUs 101) may be placed in the same housing / frame as corrector 102. Any of the above implementations may be combined or rearranged depending on the specific use case involved and / or the environment in which HUD 100 is arranged / set up.

[0031] Figure 2 An example FoV and SDoF model 300 for a HUD is depicted, showing an eyebox 104 associated with a virtual image 301. The distance between the eyebox 104 and the closest segment of the 3D virtual image 301 is the minimum virtual image distance (VID) 310. The distance between the eyebox 104 and the farthest segment of the 3D virtual image 321 is called the maximum VID 311. The FoV includes a horizontal FoV (HFoV) 320 and a vertical FoV (VFoV) 330 specified in degrees (°), which define the display size or display area. In some implementations, the FoV of the HUD can be defined based on the area of ​​the entire display area that the observer / eyebox 104 can view, or can be expressed as the entire display area that can be observed by the observer / eyebox 104. The model 300 of the HUD has a stereoscopic depth of field 325 (ie, SDoF 325 ), which is the range or length of distances at which virtual objects may be displayed at different distances to supplement the real world surroundings viewed by the observer / eye box 104 .

[0032] Figure 4 The shape of a virtual image surface (VIS) 401 is shown according to various embodiments. In particular, a virtual image distance (VID) 410 from the eyebox 104 to the surface of the VIS 401 is shown in the vertical portion 400a and the horizontal portion 400b. Here, the VIS 401 is curved, and in some implementations, the VIS 401 may have a cylindrical shape or some other suitable shape. The vertical portion 400a includes a VFoV 430, and the horizontal portion 400b includes a HFoV 420. The ray path includes a ray having a maximum length L max The maximum VID 410 (in meters (m)). The maximum VID 410 includes the minimum length L min The minimum (min) VID 415 and SDoF 425 (expressed in meters (m)). The minimum VID 415 is the distance from the eyebox 104 to the vertex 422 of the cylindrical VIS 401, and the linearly measured SDoF 425 is the distance from the vertex 422 to the end (or maximum extent) of the VIS 401.

[0033] Figure 5 The shape of the VIS 401 of FIG. 1 is shown for a specific use case, wherein the vertical portion 500a corresponds to Figure 4 The vertical portion 400a and the horizontal portion 500b correspond to Figure 4 The horizontal portion 400b. Figure 4 In the example, the maximum VID 410 is 16.1m (e.g. L max =16.1m), the minimum VID 415 is 7.2m (for example, L min =7.2 m), and the linearly measured SDoF 425 is 8.9 m (eg, SDoF=8.9 m).

[0034] Additionally or alternatively, an example implementation of HUD 100 may include the parameters shown in Table 0.

[0035] Table 0: Optical system parameter examples

[0036]

[0037] Other values ​​for various parameters of an example implementation of HUD 100 are listed in Table 1.

[0038] Table 1: Examples of optical system parameters

[0039]

[0040]

[0041] In Table 1, "H-K9L" refers to borosilicate glass (sometimes called boron crown glass) used for optical components, which may have a refractive index of about 1.509 to 1.517 and a dispersion (Abbe number) of about 64.17 to 64.20. H-K9L is equivalent to and And other properties of this type of material are Optical Glass Series Data Sheet, available at the following URL:

[0042] https: / / www.schott.com / en-gb / products / optical-glass-p1000267 / downl oads

[0043] Schott AG (2014) ([Schott]), the contents of which are hereby incorporated by reference in their entirety. Additional or alternative materials that may be used include fused silica, calcium fluoride (CaF 2 ), zinc selenide (SeZn or ZnSe), germanium, and / or any other optical material with relatively high transmittance, such as those discussed in Schott.

[0044] In various implementations, the optical system (eg, HUD 100) includes spherical, cylindrical, and / or free-form surfaces. In some implementations, the lens 202 of the corrector 102 includes two cylindrical surfaces represented by equation (1).

[0045]

[0046] In equation (1), z is the sag of lens 202, and R x ,R y and k x ,k y are the radius of the two orthogonal sections and the cone constant. In particular, R x is the radius of curvature (RoC) in the horizontal portion 400b, R y is the RoC in the vertical portion 400a, k x is the cone constant of the horizontal portion 400b, and k y is the cone constant of the vertical portion 400a. In some implementations, the refractive surface of the prism 203 is a free-form surface, which can be expressed by equation (2).

[0047]

[0048] In equation (2), z is the sag of prism 203, R is the second order RoC, k is the second order cone constant, and A i is the polynomial E i The holographic combiner 103 represents a phase grating formed on a spherical substrate for a wavelength of 532 nanometers (nm), where the phase of the surface is given by equation (3).

[0049]

[0050] In equation (3), Φ is the phase of the surface, M is the diffraction order equal to 1, and A i is the Zernike Fringe polynomial Z i The coefficients on the surfaces 7 and 12 are listed in Table 2. i The coefficient A on the term i , for the polynomial Z of the holographic combiner 103 i The coefficient A on the term i Listed in Table 3.

[0051] Table 2: Coefficients of the polynomial terms for surfaces 7 and 12

[0052]

[0053]

[0054] Table 3: Coefficients on the Zernike Fringe polynomials

[0055]

[0056]

[0057] Figure 6 A VIS comparison of two optical systems of AR HUD 600a and AR HUD 600b is shown. AR HUD 600a and 600b include prisms 603a and 603b, respectively, and are capable of generating VIS. Specifically, AR HUD 600b is configured to generate a planar VIS 601b without SDoF, while AR HUD 600a is configured to generate a curved VIS 601a with SDoF (e.g., SDoF 25).

[0058] To create the curved VIS 601a, the AR HUD 600a includes at least one rotationally asymmetric and / or free-form optical surface 630a, which enables the optical path length of light rays (propagating from the PGU to the combiner) to increase monotonically from the center of the FoV (e.g., vertex 622) along the direction of the HFoV 420, and thus provides the SDoF 425. However, an AR HUD having a planar VIS without an SDoF (e.g., AR HUD 600b) may also include a rotationally asymmetric optical surface. Therefore, to create the SDoF 425, the difference in the surface sag (or sagittal plane) in the two nearly identical correctors 102 of the optical systems 600a and 600b is based on the shape, curve and / or other properties of the optical surfaces 630a and 630b of the prisms 603a and 603b. Specifically, in this example, the two AR HUDs 600a and 600b differ only in the shapes of the respective optical surfaces 630a and 630b of their respective prisms 603a and 603b. In other words, the optical surface 630a of the prism 603a has a shape, curve and / or other properties that are different from the shape, curve and / or other properties of the optical surface 630b of the prism 603b.

[0059] Figure 7A graph 700 is included showing a comparison of prism surface sag in AR HUD 600a and AR HUD 600b. The x-axis of graph 700 includes optical surface x-coordinate values ​​(in millimeters), and the y-axis of graph 700 includes surface sag values ​​(in millimeters). In graph 700, curve 701a corresponds to the sag of optical surface 630a of prism 603a, curve 701b corresponds to the sag of optical surface 630b of prism 603b, and difference curve 711 is the difference between curves 701a and 701b. Difference curve 711 increases monotonically from the center of FoV along the HFoV direction. Considering the fact that all other optical surfaces (except surfaces 630a and 630b) in the AR HUD 600a and the AR HUD 600b are equal, the monotonic increase of the difference curve 711 can explain the monotonic increase of the optical path length in the AR HUD 600a for the light rays propagating from the PGU 101 to the combiner 103 via the corrector 102. The monotonic increase of the optical path length provides the SDoF 425 and the visual ergonomic effect of the front side.

[0060] Figure 8 An example driving scenario is shown in which vehicles 820a, 820b are performing a turn maneuver using virtual navigation arrows that guide the routes of the vehicles 820a, 820b. The vehicle 820b includes an AR HUD that generates a VIS shape 800b, wherein the virtual navigation arrows do not correspond to the real track 803. The VIS shape 800b has a VIS 801b along which the virtual objects will be placed. The VIS shape 800b also includes a virtual interface 811b that shows the direction and / or orientation of the virtual objects when displayed with the real world objects. Here, the convex side 802b of the VIS shape 800b is pointed away from the observer in the vehicle 820b. This means that the virtual image will be placed along the VIS 801b and the virtual interface 811b pointing to the vertex of the convex side 802b. In this example, when vehicle 820b approaches the intersection to make a right turn maneuver, the virtual driving arrow on the right side of the observer's field of view points to the left front instead of the right front, which may lead to a disorienting and unsafe driving scenario.

[0061] Figure 8 The AR HUD (e.g., Figure 6800a) with a virtual driving direction corresponding to a real track 803. The VIS shape 800a has a VIS 801a, along which virtual objects will be placed, and a virtual interface 811a, which displays the direction and / or orientation of the virtual objects when displayed with real-world objects. Here, the convex side 802a of the VIS shape 800a is toward the observer in the vehicle 820a. This means that the virtual image will be placed along the VIS 801a and the virtual interface 811a pointing away from the vertex of the convex side 802a. In this example, when the vehicle 820a approaches the intersection to make a right turn maneuver, the virtual driving arrow on the right side of the observer's field of view will be directed to the right front, consistent with the real track 803. Unlike the VIS shape 800b, the convex side 802a of the VIS shape 800a is oriented toward the observer, so that the virtual object (e.g., TBT pointer / arrow) corresponds to the real-world object (e.g., real track 803). The aforementioned implementation and the various embodiments discussed below provide advantages over conventional HUDs because the shape of the VIS 801a (including the SDoF) allows the virtual driving direction to be displayed based on the natural perception of the real driving direction. For example, when the AR HUD 100 displays a TBT pointer for the driving route, the shape of the VIS 801a (including the SDoF) enables the TBT pointer to be displayed on or at the real-world driving direction (real track 803). In the conventional HUD discussed above, the VIS is provided with a convex side oriented away from the observer, which is opposite to the direction of the VIS generated according to the embodiments of the present case.

[0062] Fig. 9 An example driving scenario is shown in which vehicles 920a, 920b are following (or approaching) another vehicle 922a, 922b. Vehicle 920a includes an AR HUD (e.g., Figure 6 AR HUD 600a), which can be used with Figure 8 Here, VIS shape 900a "wraps" around vehicle 922a in front of vehicle 920a. In contrast, vehicle 920b includes an AR HUD that generates VIS shape 900b, which can be used with Figure 8The VIS shape 900b is the same as or similar to the VIS shape 800b of the vehicle 920b. Here, the VIS shape 900b surrounds or overlaps the vehicle 922b in front of the vehicle 920b. In this case, the virtual image placed along the VIS shape 900b will appear to be farther away from the vehicle 920b than the front vehicle 922b. The situation where virtual objects overlap with real-world objects (e.g., the front vehicle 922b) or are displayed outside the real-world objects (e.g., outside the front vehicle 922b) may be quite unpleasant in terms of visual perception comfort and driving safety. In other words, the distance of the displayed virtual objects does not correctly correspond to the distance of the real objects they should be supplemented with. This situation may often occur in crowded areas, such as highways or urban environments, where speeds are generally low and / or vehicles are relatively close to each other.

[0063] Fig.10 An example partitioning rule 1000 for partitioning the HFoV into segments 1010 according to various embodiments is depicted. As previously described, an optical system (e.g., HUD 100) improves visual perception quality by imaging virtual objects in the display FoV according to a natural viewing angle. The corrector 102 is implemented in such a way that, for a ray 1015 propagating from the PGU 101 to the combiner 103, it enables the optical path length to increase monotonically from the center of the FoV along the direction of the HFoV. Therefore, the VIS 401 has a U-shape and / or a cylindrical shape with a convex side 1022 facing the observer 104. In addition, the side regions of the VIS 401 gradually move away from the observer 104. At the same time, as the chief ray 1015 travels away from the center of the convex side 1022 of the FoV, the angle between any chief ray 1015 aimed along the HFoV direction and the normal of the VIS 1001 becomes larger. This means that the available size of a virtual object, which appears not to be tilted, will appear smaller the further the virtual object is from the viewer 104 and therefore from the center of the FoV along the direction of the HFoV.

[0064] The segmentation rule 1000 includes a set of local segments 1010 (or simply "segments 1010"). Fig.10 , only half of the HFoV segments 1010 are shown. Each segment 1010 has two endpoints 1005 based on a respective ray 1015 between the observer 104 and the VIS 1001. In the present implementation, each segment 1010 has an SDoF of approximately 150 arc seconds ("). Here, if the true stereo threshold of the interface is at or near 150", the virtual objects displayed within each segment 1010 should not appear tilted to the observer 104. According to an exemplary embodiment, the angular size of each local segment 1010 is determined by the angle of the local segment 1010. Fig.10 (in degrees), but other angle sizes are possible in other implementations.

[0065] The segmentation rule 1000 also includes an angle α at each end point 1005 between two segments 1010 (note that for clarity, Fig.10 Only two angles are shown, angle α 1 and angle α 2 ). Each angle α is the angle between the normal 1002 of the VIS 1001 and the light 1015 propagating between the observer 104 and the VIS 401. Here, the angle α 1 is the normal 1002 of VIS 1001 and the first principal ray 1015 1 The angle between 2 is the normal 1002 of VIS 1001 and the second principal ray 1015 2 The angle between the second main ray 1015 2 1015 times the first principal ray 1 propagates further away from the center of the FoV, and the first chief ray 1015 1 Propagates 1015 times longer than the second principal ray 2 closer to the center of the FoV. In this implementation, the angle α 2 Greater than angle α 1 , and the segment 1010 closer to the observer 104 has a larger angular size than the segment 1010 farther from the observer 104. This characteristic corresponds to the natural perspective of the observer 104. Displaying virtual objects according to the natural perspective can improve the quality of visual perception by more effectively utilizing FoV and SDoF, because the natural perspective corresponds to the perception of real humans to 3D space.

[0066] Fig.11 Depicting the SDoF model 1100. As previously described, since the AR HUD 100 provides a greater SDoF, the AR HUD 100 may provide improved visual ergonomics compared to existing / conventional AR HUDs. The SDoF δ may be expressed as the difference between the angle ω of convergence on an object A located close to the eye box 104 and the angle θ of an object B located far from the eye box 104. The SDoF δ may be calculated using equation (4).

[0067] δ=ω-θ (4)

[0068] The difference between these angles depends on the viewing distance L to the object, the interocular distance b, and therefore SDoFδ can also be expressed using equation (5).

[0069]

[0070] In equation (5), the viewing distance L 1 is the visual distance between the eye box 104 and the object A, the visual distance L2 is the visual distance between the eye box 104 and the object B, and b is the inter-eye distance. 1 and sight distance L 2 The difference between them is the perceived depth Δd measured linearly. In one example implementation, the viewing distance L 1 and L 2 Varying in the range of 7.2m to 16.1m (e.g., Δd=8.9m) and interocular distance b, SDoFδ is equal to 4.9 milliradians (mrad). In the AR HUD 100, the SDoFδ achieved through a wider FoV becomes larger, while the size of virtual objects that do not exceed the stereo threshold (e.g., the virtual objects do not appear tilted) remains unaffected.

[0071] Fig.12 Shows the dependence of SDoF on the size of FoV. Here, SDoF increases as the FoV becomes wider. Fig.12 In FIG. 1 , VIS 1201 has a one-dimensional tilt around the center point of the FoV. For example, assuming that the tilt angle 1223 is 79° (e.g., α=79°), and the center point 1210 of the FoV is 10 m away from the observer 104, then the SDoFδ for the 4° FoV 1220 will be 2.3 mrad, and for the 7° FoV 21, the SDoFδ will be 4.1 mrad. Converted to distance range, for FoV 1220, the perceived depth is 3.7 m (e.g., Δd=3.7 m), and for FoV 1221, the perceived depth is 7.1 m (e.g., Δd'=3.7 m).

[0072] Fig.13 The maximum available size 1330 of the virtual object 1302 is displayed, which does not exceed the stereoscopic threshold 1340. Here, the maximum available size 1330 of the virtual object 1302 that does not exceed the stereoscopic threshold 1340 is a size at which the virtual object does not appear to be tilted toward the observer 104. Fig.13 In the example of 1340, the stereo threshold is 150".

[0073] One of the reasons why the AR HUD 100 may have a larger SDoF than the SDoF in existing / conventional AR HUDs is that the SDoF of the ARHUD 100 is achieved in the HFoV direction, whereas the SDoF in existing / conventional AR HUDs is achieved in the VFoV direction. Fig.14 Shows the difficulty of increasing the VFoV size for typical AR HUD geometries. Fig.14 As shown, the difficulty of increasing the size of the VFoV compared to increasing the HFoV is based on the relationship between the projected length L of the combiner 1403 on the vertical plane 1410 and the actual size L′ of the combiner 1403 .

[0074] The typical combiner 1403 tilt angle 1423 is no less than 60 degrees (e.g., α≧60), and the vertical dimension L' of the combiner 1403 will be at least twice larger than its projection on the vertical plane 1410. However, there is no such problem for the horizontal plane. Therefore, all things being equal, the maximum achievable typical VFoV will be at least twice smaller than the HFoV due to the limit of the combiner size L', the large numerical aperture, and the fact that aberrations increase rapidly in the VFoV direction (especially astigmatism). This can also be illustrated by the typical values ​​of FoV of existing HUDs, including the previously discussed 5.4x1.8; 10×4; 12x3 degrees.

[0075] Another reason why the AR HUD 100 can have a larger SDoF than existing / conventional AR HUDs is that the combiner 103 is implemented as a holographic optical element (HOE) with positive optical power, which can further increase the HFoV and VFoV compared to existing HUDs (see, e.g. Fig.12 , showing the dependency between SDoF and FoV size). In an example implementation, the optical magnification of the combiner 103 is 2.85 diopters, and the combiner focal length is 350mm. In existing / traditional AR HUDs, one of the factors limiting the expansion of FoV is the limit of the combiner size, which is related to the low optical magnification of the combiner (~<1 diopters). The lower the optical magnification of the combiner, the smaller the achievable field of view, but the optical system size is still limited.

[0076] Fig.15 A graph 1500 is depicted showing the dependence of the volume of a typical AR HUD on the optical magnification of the combiner for different distances to the virtual image. The data given in graph 1500 is provided in millimeters (mm) for different distances from the virtual image. Fig.15 , a typical AR HUD gives the following system parameter values: the distance from the eye box to the combiner is 700mm, the radius of the circular eye box is 71mm, and the FoV radius is 6.5°.

[0077] Graph 1500 shows that the volume of a typical AR HUD increases quite rapidly given sufficient distances of the virtual image (>3m). The optical magnification or focal length of the combiner is implemented as an area of ​​the windshield and can be estimated by considering the minimum closest radius of curvature at that area. Thus, the typical focal length of a conventional combiner is typically greater than 1000mm, while the holographic combiner 103 of the AR HUD 100 has a significantly higher optical magnification (e.g., shorter focal length). The high optical magnification enables the holographic AR HUD 100 to have a wider FoV and therefore a larger SDoF, thereby providing improved visual ergonomics.

[0078] In addition to the various embodiments of the HUD 100 previously described, the HUD 100 may also contain additional or alternative elements other than those shown. For example, the HUD 100 may also include one or more additional optical elements / components that manipulate light, such as lenses, filters, prisms, mirrors, beam splitters, diffusers, diffraction gratings, multivariate optical elements (MOEs), etc. In addition, the various elements / components shown and described herein may be manufactured or constructed using any suitable manufacturing means (such as those discussed herein). In addition, the various elements / components shown and described herein may be connected to other elements / components and / or to a portion / section of a vehicle by any suitable fastening device (such as those discussed herein). In addition, the geometry (shape, volume, etc.), position, orientation and / or other parameters of the elements / components shown and described herein may be different from the shapes, positions, orientations and / or other parameters described in the example embodiments of FIGS. 1-15 , depending on the shape, size and / or other parameters / characteristics of the vehicle in which the AR HUD 100 is configured, and / or based on the shapes, sizes, positions, orientations and / or other parameters / characteristics of other elements / components of the AR HUD 100 and / or the vehicle in which the AR HUD 100 is configured.

[0079] 2. Example Implementation

[0080] Some non-limiting examples are provided below. The following examples involve further embodiments. The details in the examples can be used anywhere in one or more embodiments. All optional features of the device described in this disclosure can also be implemented for the method or program.

[0081] Example A01 includes an optical system comprising a picture generating unit (PGU), a combiner, and a corrector disposed between the PGU and the combiner, wherein the corrector includes at least one rotationally asymmetric optical surface arranged to provide a stereoscopic depth of field (SDoF) for light propagating from the PGU through the corrector to the combiner by monotonically increasing the optical path length from the center of the field of view (FoV) along a horizontal FoV (HFoV) direction.

[0082] Example A02 includes the optical system of Example A01 and / or some other examples of the present disclosure, wherein at least one rotationally asymmetric optical surface is configured to form a curved virtual image surface (VIS) based on light projected by the PGU.

[0083] Example A03 includes the optical system of Example A01 or A02 and / or some other examples of the present disclosure, wherein the optical system is configured to form a curved virtual image surface (VIS) due to the interaction between the PGU, the corrector, and the combiner, and to improve the visual ergonomics (e.g., driving comfort and safety) of the optical system by aligning one or more real objects with one or more displayed virtual images.

[0084] Example A04 includes the optical system of Example A03 and / or some other examples of the present disclosure, wherein one or more real objects include real driving directions, and one or more displayed virtual images include displayed virtual driving directions, and the displayed virtual driving directions are one or more of a route planning (TBT) pointer, a turn arrow, or other similar graphical elements of a TBT navigation service.

[0085] Example A05 includes the optical system of Examples A03-A04 and / or some other examples of the present disclosure, wherein the VIS has a cylindrical shape, and the convex side of the cylindrical shape is directed toward the observer.

[0086] Example A06 includes the optical system of example A05 and / or some other examples of the present disclosure, wherein the directrix of the VIS is a continuous curve positioned along the direction of the HFoV.

[0087] Example A07 includes the optical system of Examples A01-A06 and / or some other examples of the present disclosure, wherein the corrector is implemented as a combination of optical surfaces including one or more refractive surfaces, one or more reflective surfaces, or a combination of at least one refractive surface and at least one reflective surface.

[0088] Example A08 includes the optical system of Examples A01-A07 and / or some other examples of the present disclosure, wherein the combiner is implemented as a holographic optical element with positive optical power.

[0089] Example A09 includes the optical system of Examples A01-A08 and / or some other examples of the present disclosure, wherein the corrector is configured to produce an optical path length that increases monotonically from the center of the FoV in the direction of the HFoV for light rays propagating from the PGU to the combiner to form the VIS, so that the angle between the chief ray and the aimed chief ray increases along the HFoV direction and the distance from the VIS normal as the chief ray is farther from the center of the FoV.

[0090] Example A09 includes the optical system of examples A01-A08 and / or some other examples of the present disclosure, wherein the optical system displays virtual objects at different distances from an observer according to natural perspective.

[0091] Example A10 includes the optical system of examples A01-A09 and / or some other examples of the present disclosure, wherein the corrector further includes at least one prism including at least one reflective optical surface disposed between at least two refractive optical surfaces.

[0092] Example A11 includes the optical system of example A10 and / or some other examples of the disclosure, wherein the at least two refractive optical surfaces are surfaces of the at least one prism.

[0093] Example A12 includes the optical system of examples A01-A11 and / or some other examples of the disclosure, wherein the combiner includes a holographic optical element (HOE) having an optical power between 1.1-6.6 diopters.

[0094] Example A13 includes the optical system of Examples A01-A12 and / or some other examples of the present disclosure, wherein the combiner includes a HOW having an optical power of 2.85 diopters and a focal length of 350 millimeters (mm).

[0095] Example A14 includes the optical system of Examples A01-A13 and / or some other examples of the present disclosure, wherein the corrector includes at least one optical element having at least two refractive surfaces.

[0096] Example A15 includes the optical system of Examples A01-A14 and / or some other examples of the present disclosure, wherein the PGU is communicatively coupled to a vehicle-mounted computing system, and the PGU is configured to generate a three-dimensional (3D) virtual image based on a signal obtained from the vehicle-mounted computing system.

[0097] Example A16 includes the optical system of Examples A01-A15 and / or some other examples of the present disclosure, wherein the optical system is, or is incorporated into, an augmented reality (AR) head-up display (HUD) device with improved visual ergonomics.

[0098] Example B01 includes an optical system comprising: a combiner; a picture generating unit (PGU) configured to project light toward the combiner; and a corrective optical component disposed between the PGU and the combiner, wherein the corrective optical component includes at least one rotationally asymmetric optical surface arranged to provide a stereoscopic depth of field (SDoF) by generating an optical path having a monotonically increasing optical path length for light to propagate through the corrective optical component PGU to a horizontal field of view (HFoV) of the combiner.

[0099] Example B02 includes the optical system of Example B01 and / or some other examples of the present disclosure, wherein no SDoF is provided in the direction of the vertical field of view (VFoV).

[0100] Example B03 includes the optical system of examples B01-B02 and / or some other examples of the present disclosure, wherein at least one rotationally asymmetric optical surface is configured to form a curved virtual image surface (VIS) based on light propagating from the PGU.

[0101] Example B04 includes the optical system of example B03 and / or some other examples of the present disclosure, wherein the apex of the curved VIS is directed toward the observer.

[0102] Example B05 includes the optical system of examples B03-B04 and / or some other examples of the present disclosure, wherein the VIS has a cylindrical shape, and the convex side of the cylindrical shape is directed toward the observer.

[0103] Example B06 includes the optical system of example B05 and / or some other examples of the present disclosure, wherein the directrix of the curved VIS is a continuous curve positioned along the direction of the HFoV.

[0104] Example B07 includes the optical system of examples B01-B06 and / or some other examples of the present disclosure, wherein the directrix of the curved VIS is a continuous curve positioned along the direction of the HFoV.

[0105] Example B08 includes the optical system of examples B01-B07 and / or some other examples of the present disclosure, wherein the monotonically increasing optical path length increases monotonically from a center point of a field of view (FoV) in a direction of the HFoV.

[0106] Example B09 includes the optical system of examples B01-B08 and / or some other examples of the present disclosure, wherein a first angle between a first chief ray and a normal to the VIS is smaller than a second angle between a second chief ray and the normal to the VIS, wherein the first chief ray is closer to the center of the FoV than the second chief ray, and both the first chief ray and the second chief ray are aimed along the HFoV direction.

[0107] Example B10 includes the optical system of Examples B01-B09 and / or some other examples of the present disclosure, wherein the corrective optical assembly includes at least one optical element, wherein the at least one optical element includes a plurality of surfaces.

[0108] Example B11 includes the optical system of Example B10 and / or some other examples of the present disclosure, wherein at least one optical element is formed into a three-dimensional shape, which is selected from the group consisting of a plane, a sphere, an aspheric surface, a prism, a pyramid, an ellipse, a cone, a cylinder, and a torus, or a combination of any two or more shapes of the group consisting of a plane, a sphere, an aspheric surface, a prism, a pyramid, an ellipse, a cone, a cylinder, and a ring.

[0109] Example B12 includes the optical system of examples B10-B11 and / or some other examples of the present disclosure, wherein the plurality of surfaces includes at least two refractive surfaces and at least one reflective surface.

[0110] Example B13 includes the optical system of example B12 and / or some other examples of the present disclosure, wherein the at least one rotationally asymmetric optical surface is one of the at least two refractive surfaces.

[0111] Example B14 includes the optical system of examples B12-B13 and / or some other examples of the present disclosure, wherein at least one reflective surface is disposed between each of the at least two refractive surfaces.

[0112] Example B15 includes an optical system of Example B14 and / or some other examples of the present disclosure, wherein the first surface of at least two refractive surfaces is a spherical surface, a non-spherical surface, a deformed surface or a free-form surface; and the second surface of the at least two refractive surfaces is a spherical surface, a non-spherical surface, a deformed surface or a free-form surface.

[0113] Example B16 includes the optical system of examples B14-B15 and / or some other examples of the present disclosure, wherein each of the at least two refractive surfaces is a freeform optical surface and at least one reflective surface is a planar optical surface.

[0114] Example B17 includes an optical system of Example B16 and / or some other examples of the present disclosure, wherein the free-form surface is formed based on a function selected from the group consisting of radial basis functions, basis splines, non-uniform rational basis splines, orthogonal polynomials, non-orthogonal polynomials, and a hybrid stitched representation of a combination of two or more functions selected from the group consisting of radial basis functions, basis splines, non-uniform rational basis splines, orthogonal polynomials, and non-orthogonal polynomials.

[0115] Example B18 includes the optical system of examples B12-B17 and / or some other examples of the disclosure, wherein at least one rotationally asymmetric optical surface is directed toward the combiner.

[0116] Example B19 includes the optical system of examples B12-B18 and / or some other examples of the present disclosure, wherein at least one optical element is a prism.

[0117] Example B20 includes the optical system of Example B19 and / or some other examples of the present disclosure, wherein the corrective optical assembly further includes a lens disposed between the prism and the PGU.

[0118] Example B21 includes the optical system of example B20 and / or some other examples of the present disclosure, wherein the lens includes at least two cylindrical optical surfaces.

[0119] Example B22 includes the optical system of Example B21 and / or some other examples of the present disclosure, wherein the lens includes a concave surface directed toward the PGU.

[0120] Example B23 includes the optical system of Examples B21-B22 and / or some other examples of the present disclosure, wherein the lens is a telecentric lens.

[0121] Example B24 includes the optical system of Examples B01-B23 and / or some other examples of the present disclosure, wherein the corrective optical component includes one or more lenses, one or more prisms, one or more prismatic lenses, one or more mirrors, one or more holographic optical elements.

[0122] Example B25 includes the optical system of Example B24 and / or some other examples of the present disclosure, wherein the corrective optical component further includes a diffuser element onto which light is projected by the PGU, wherein the diffuser element includes a combination of one or more diffuse screens, diffuser plates, scattering surfaces or microlens arrays.

[0123] Example B26 includes the optical system of examples B01-B25 and / or some other examples of the disclosure, wherein the combiner includes a holographic optical element (HOE) with positive optical power.

[0124] Example B27 includes the optical system of Example B26 and / or some other examples of the present disclosure, wherein the optical power of the HOE is between 1.1 and 6.6 diopters.

[0125] Example B28 includes the optical system of example B27 and / or some other examples of the present disclosure, wherein the optical power of the HOE is between 2.85 diopters.

[0126] Example B29 includes the optical system of Example B28 and / or some other examples of the present disclosure, wherein the HOE has a focal length of 350 millimeters (mm).

[0127] Example B30 includes an optical system of Examples B01-B29 and / or some other examples of the present disclosure, wherein the PGU is communicatively coupled to a vehicle-mounted computing system, and the PGU is configured to generate light based on a signal obtained from the vehicle-mounted computing system, wherein the light represents one or more three-dimensional (3D) virtual images.

[0128] Example B31 includes the optical system of Examples B01-B30 and / or some other examples of the present disclosure, wherein the optical system is, or is incorporated into, an augmented reality (AR) head-up display (HUD) device.

[0129] Example C01 includes an optical system comprising: a combiner; an image generation unit (PGU) configured to project light toward the combiner; and a corrective optical component disposed between the PGU and the combiner, wherein the corrective optical component includes at least one rotationally asymmetric optical surface arranged to form a virtual image surface (VIS) with its vertex facing an observer, this is achieved by generating an optical path having an optical path length that monotonically increases from the vertex in the direction of a horizontal field of view (HFoV) from propagating light rays to propagate from the PGU to the combiner through the corrective optical component, so that the optical system can provide a stereoscopic depth of field (SDoF) to display virtual objects at different distances from the observer.

[0130] Example C02 includes the optical system of example C01 and / or some other examples of the present disclosure, wherein the monotonically increasing optical path length increases monotonically from a center point of a field of view (FoV) in a direction of the HFoV.

[0131] Example C03 includes the optical system of example C02 and / or some other examples of the present disclosure, wherein a first angle between a first chief ray and a VIS normal is smaller than a second angle between a second chief ray and the VIS normal, wherein the first chief ray is closer to a center of the FoV than the second chief ray, and both the first chief ray and the second chief ray are aimed along a HFoV direction.

[0132] Example C04 includes the optical system of example C03 and / or some other examples of the present disclosure, wherein the optical system displays virtual objects at different distances from an observer according to natural perspective.

[0133] Example C05 includes the optical system of examples C01-C04 and / or some other examples of the present disclosure, wherein the VIS has a cylindrical shape, and the convex side of the cylindrical shape is directed toward the observer.

[0134] Example C06 includes the optical system of example C05 and / or some other examples of the disclosure, wherein the VIS has a directrix that is a continuous curve positioned along the direction of the HFoV.

[0135] Example C07 includes the optical system of example C05 and / or some other examples of the present disclosure, wherein the VIS has a directrix that is a continuous curve extending linearly in the direction of the HFoV.

[0136] Example C08 includes the optical system of examples C01-C07 and / or some other examples herein, wherein the combiner includes a holographic optical element (HOE) with positive optical power.

[0137] Example C09 includes the optical system of example C08 and / or some other examples of the present disclosure, wherein the optical power of the HOE is between 1.1 and 6.6 diopters.

[0138] Example C10 includes the optical system of examples C01-C09 and / or some other examples of the present disclosure, wherein the corrective optical assembly includes at least one optical element, and the at least one optical element includes a plurality of surfaces.

[0139] Example C11 includes the optical system of Example C10 and / or some other examples of the present disclosure, wherein a plurality of surfaces are formed into a three-dimensional shape including at least one rotationally asymmetric optical surface and one or more additional optical surfaces, wherein individual additional optical surfaces of the one or more additional optical surfaces are selected from the group consisting of a plane, a sphere, an asphericity, a cylinder, an annulus, a bicone, and a free form.

[0140] Example C12 includes the optical system of Example C10 and / or some other examples of the present disclosure, wherein a plurality of surfaces are formed into a three-dimensional shape including the at least one rotationally asymmetric optical surface and one or more additional optical surfaces, wherein individual additional optical surfaces of the one or more additional optical surfaces are planar surfaces, spherical surfaces, aspherical surfaces, cylindrical surfaces, annular surfaces, biconical surfaces, or free-form surfaces.

[0141] Example C13 includes an optical system of Examples C10-C12 and / or some other examples of the present disclosure, wherein the plurality of surfaces include at least two refractive optical surfaces and at least one reflective optical surface, and at least one optical element is formed such that the at least one reflective optical surface is disposed between individual refractive optical surfaces of the at least two refractive optical surfaces.

[0142] Example C14 includes the optical system of example C13 and / or some other examples of the present disclosure, wherein the at least one rotationally asymmetric optical surface is one of the at least two refractive optical surfaces.

[0143] Example C15 includes the optical system of examples C13-C14 and / or some other examples of the present disclosure, wherein at least one optical element is a prism.

[0144] Example C16 includes an optical system of Examples C13-C15 and / or some other examples of the present disclosure, wherein the first surface of at least two refractive optical surfaces is a spherical surface, an aspherical surface, a biconical surface or a free-form surface; and the second surface of the at least two refractive optical surfaces is a spherical surface, an aspherical surface, a biconical surface or a free-form surface.

[0145] Example C17 includes the optical system of examples C13-C16 and / or some other examples of the present disclosure, wherein at least one optical reflective optical surface is a spherical surface, a non-spherical surface, a biconical surface, or a free-form surface.

[0146] Example C18 includes the optical system of examples C13-C17 and / or some other examples of the present disclosure, wherein each of the at least two refractive optical surfaces is a freeform optical surface and at least one reflective optical surface is a planar optical surface.

[0147] Example C19 includes the optical system of Examples C10-C18 and / or some other examples of the present disclosure, wherein the corrective optical component further includes one or more additional optical elements, wherein the one or more additional optical elements include one or more of lenses, filters, prisms, mirrors, beam splitters, diffusers, diffraction gratings, and multivariate optical elements.

[0148] Example C20 includes the optical system of examples C01-C19 and / or some other examples of the present disclosure, wherein the optical system is, or is incorporated into, an augmented reality (AR) head-up display (HUD) device with improved visual ergonomics.

[0149] Example D01 includes an optical system for an augmented reality (AR) head-up display (HUD) device with improved visual ergonomics, the optical system comprising: a combiner comprising a holographic optical element (HOE) having a positive optical power; a picture generation unit (PGU) configured to project light toward the combiner; and a corrective optical component disposed between the PGU and the combiner, wherein the corrective optical component comprises at least one rotationally asymmetric optical surface arranged to provide a stereo depth of field (SDoF) by generating a monotonically increasing optical path along a horizontal field of view (HFoV) for light propagating from the PGU to the combiner, so that the optical system is able to display virtual objects at different distances from an observer.

[0150] Example D02 includes the optical system of example D01 and / or some other examples of the present disclosure, wherein the monotonically increasing optical path increases monotonically from a center point of a field of view (FoV) along a direction of the HFoV.

[0151] Example D03 includes the optical system of Examples D01-D02 and / or some other examples of the present disclosure, wherein at least one rotationally asymmetric optical surface is configured to form a curved virtual image surface (VIS) based on light propagating from the PGU, and wherein the curved VIS has a cylindrical shape, the vertex of the curved VIS is toward the observer, and the directrix of the curved VIS is a continuous curve extending in the horizontal field of view (HFoV) direction.

[0152] Example D04 includes the optical system of example D03 and / or some other examples of the present disclosure, wherein the corrective optical assembly includes at least one optical element, and the at least one optical element includes at least two refractive optical surfaces and at least one reflective optical surface.

[0153] Example D05 includes the optical system of Example D04 and / or some other examples of the present disclosure, wherein the at least one optical element is formed to have a prism shape, and the at least one reflective optical surface is disposed between respective refractive optical surfaces of the at least two refractive optical surfaces.

[0154] Example D06 includes an optical system of Examples D04-D05 and / or some other examples of the present disclosure, wherein the at least one rotationally asymmetric optical surface is one of the at least two refractive optical surfaces, and one of the at least two refractive optical surfaces is a flat or planar surface, a spherical surface, an aspherical surface, a cylindrical surface, an annular surface, a biconical surface or a free-form surface, and wherein the at least one reflective optical surface is a planar surface, a spherical surface, an aspherical surface, a cylindrical surface or a cylindrical surface, an annular surface, a biconical surface or a free-form surface.

[0155] Example D07 includes the optical system of examples D04-D06 and / or some other examples of the present disclosure, wherein each of the at least two refractive optical surfaces is a freeform optical surface and at least one reflective optical surface is a planar optical surface.

[0156] Example E01 includes an optical system of an augmented reality head-up display device with improved visual ergonomics, comprising: a combiner device for displaying one or more virtual objects; an image generating device for projecting light rays representing the one or more virtual objects toward the combiner device; and a corrective optical device arranged between the image generating device and the combiner device, wherein the corrective optical device is used to form a virtual image surface (VIS) whose vertex is toward an observer by generating an optical path having an optical path length that monotonically increases from the vertex in a horizontal field of view (HFoV) direction of the light rays propagating from the image generating device to the combiner device, so that the optical system can provide a stereo depth of field (SDoF) to display one or more virtual objects at different distances from the observer.

[0157] Example E02 includes the optical system of example E01 and / or some other examples of the present disclosure, wherein the monotonically increasing optical path length increases monotonically from a center point of a field of view (FoV) along a direction of the HFoV.

[0158] Example E03 includes the optical system of Example E02 and / or some other examples of the present disclosure, wherein a first angle between a first chief ray and a normal to the VIS is smaller than a second angle between a second chief ray and the normal to the VIS, wherein the first chief ray is closer to the center of the FoV than the second chief ray, and both the first and second chief rays are aimed along the direction of the HFoV.

[0159] Example E04 includes the optical system of example E03 and / or some other examples of the present disclosure, wherein the correction optical device is used to form a VIS so that one or more virtual objects are displayed at different distances from the observer according to natural perspective.

[0160] Example E05 includes the optical system of examples E01-E04 and / or some other examples of the present disclosure, wherein the VIS has a cylindrical shape, and the convex side of the cylindrical shape is directed toward the observer.

[0161] Example E06 includes the optical system of example E05 and / or some other examples of the present disclosure, wherein the VIS has a continuously curved directrix positioned along the HFoV direction and / or a continuously curved directrix extending straight along the HFoV direction.

[0162] Example E07 includes the optical system of examples E01-E06 and / or some other examples of the present disclosure, wherein one or more virtual objects are holographic objects.

[0163] Example E08 includes an optical system of Examples E01-E07 and / or some other examples of the present disclosure, wherein the corrective optical device is any one or more of the corrective optical components of Examples A01-D07, the combiner device is any one or more of the combiners of Examples A01-D07, and the image generating device is any one or more of the PGUs of Examples A01-D07.

[0164] Example F01 includes a computer device communicatively coupled to the AR HUD of any one of Examples A01-E08, and the computer device is configured to generate one or more signals to control the PGU of any one or more of Examples A01-E08.

[0165] Example F02 includes one or more computer-readable media containing instructions, wherein a processor circuit executes the instructions to cause a computer device to generate one or more signals to control any one or more PGUs of Examples A01-E08.

[0166] Example F03 includes an electromagnetic signal generated as a result of executing instructions stored by one or more computer-readable media, wherein the electromagnetic signal causes any one or more PGUs in Examples A01-E08 to generate light representing any one or more virtual objects in Examples A01-E08.

[0167] 3. Terminology

[0168] As used herein, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprising" and / or "containing" when used in this specification specifically refer to the presence of the stated characteristics, entities, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other characteristics, entities, steps, operations, elements, components, and / or groups thereof. The phrase "A and / or B" means (A), (B), or (A and B). For the purposes of this disclosure, the phrase "A, B, and / or C" means (A), (B), (C), (A and B), (A and C), (B and C), or (A, B and C). The description may use the phrases "in one embodiment" or "in some embodiments", each of which may refer to one or more of the same or different embodiments. In addition, as used herein, the terms "comprising", "including", "having", etc. are synonymous.

[0169] The term "deformed surface" refers, at least in some embodiments, to an asymmetric surface having biaxial symmetry. The terms "deformed element" and / or "deformed optical element" refer to an optical element having at least one deformed surface and / or an optical element having a combination of spherical, aspherical and toroidal surfaces.

[0170] The term "aperture" refers, in at least some embodiments, to an optically relevant portion of an optical surface. Additionally or alternatively, the term "aperture" refers, in at least some embodiments, to a hole or opening through which light travels. Additionally or alternatively, the "aperture" and focal length of an optical system determine the cone angle of a bundle of light rays that arrive at a focal point in an image plane.

[0171] The term "aperture stop" refers, at least in some embodiments, to an opening or structure that limits the amount of light that passes through an optical system. Additionally or alternatively, the term "aperture stop" refers, at least in some embodiments, to a stop that primarily determines the ray cone angle and brightness at the image point. The term "stop" refers, at least in some embodiments, to an opening or structure that limits a light beam, and may include a diaphragm of an aperture, the edge of a lens or mirror, a fixture that holds an optical element in place, and / or the like.

[0172] Depending on the context, the term "facing" at least in some embodiments refers to the direction of the slope, which can be measured clockwise from 0 to 360 degrees, where 0 is facing north, 90 is facing east, 180 is facing south, and 270 is facing west.

[0173] The term "augmented reality" or "AR" refers, at least in some embodiments, to an interactive experience of a real-world environment in which objects in the real world are "augmented" by computer-generated sensory information, sometimes across multiple sensory modalities including vision, hearing, touch, body sensation, and smell.

[0174] The term "chief ray" refers, at least in some embodiments, to the central ray of a bundle of rays. Additionally or alternatively, the term "chief ray" refers, at least in some embodiments, to a ray from an off-axis object point that passes through the center of an aperture stop of an optical system. Additionally or alternatively, the term "chief ray" refers, at least in some embodiments, to a meridional ray that originates at the edge of an object and passes through the center of an aperture stop. The term "chief ray" or "chief ray" may also be referred to as "chief ray" or "b-ray".

[0175] The terms "coupled", "communicatively coupled" and their derivatives are used in this disclosure. The term "coupled" may refer to two or more elements being in direct physical or electrical contact with each other, may refer to two or more elements being in indirect contact with each other but still cooperating or interacting with each other, and / or may refer to one or more other elements being coupled or connected between the elements referred to as being coupled to each other. The term "directly coupled" may mean that two or more elements are in direct contact with each other. The term "communicatively coupled" may mean that two or more elements may be in contact with each other via communication means including through a wired or other interconnect connection, through a wireless communication channel or link, and the like.

[0176] The term "curvature" refers, at least in some embodiments, to the rate at which the direction of a curve changes with respect to the distance along the curve.

[0177] The term "diffuser" refers, at least in some embodiments, to any device or material that diffuses or scatters light in some manner. A "diffuser" may include materials that reflect light, translucent materials (e.g., glass, frosted glass, reflective glass / reflow solder, opal glass, gray glass, etc.), and / or other materials. The term "diffractive diffuser" refers, at least in some embodiments, to a diffuser or diffractive optical element (DOE) that utilizes the principles of diffraction and refraction. The term "speckle diffuser device" (also referred to as a "speckle diffuser") refers, at least in some embodiments, to a device in optics that is used to destroy the spatial coherence (or coherent interference) of laser light before it reflects from a surface.

[0178] The term "diopter" refers, at least in some embodiments, to the unit of refractive power of an optical element.

[0179] The term "directrix" refers, at least in some embodiments, to a curve associated with a process that generates geometric objects such as cylindrical surfaces.

[0180] In at least some embodiments, the term "virtual surface" refers to a surface that does not have a refractive effect and / or does not change the path of light rays. Additionally or alternatively, the term "virtual surface" refers to a reference in a description of an optical system to indicate where parts will be located when or after the optical system is manufactured; these parts may include, for example, mechanical diaphragms, apertures, shields, mounts, baffles, and / or some other mechanical parts.

[0181] The terms "self" (as in, e.g., "self device") and "subject" (as in, e.g., "data subject"), at least in some embodiments, refer to an entity, component, device, system, etc. that is being considered or under consideration. The terms "neighbor" and "neighbor" (as in, e.g., "neighboring device"), at least in some embodiments, refer to an entity, component, device, system, etc. other than the self device or subject device.

[0182] The term "element" refers, at least in some embodiments, to an indivisible unit at a given level of abstraction and having well-defined boundaries, where an element may be any type of entity including, for example, one or more devices, systems, controllers, network elements, modules, etc., or a combination thereof.

[0183] The term "eye box" refers, at least in some embodiments, to the volume of space in which a virtual image is observable, and represents a combination of the exit pupil size and the eye exit pupil distance.

[0184] The term "manufacturing" refers, at least in some embodiments, to creating a metal structure using manufacturing means. The term "manufacturing means" as used in this disclosure refers to any appropriate tool or machine used during the manufacturing process, and may involve tools or machines for cutting (e.g., using manual or electric saws, scissors, chisels, routers, torches, including hand-held torches, such as oxy-fuel torches or plasma torches, and / or computer numerical control (CNC) cutting machines, including lasers, milling cutters, torches, water jets, routers, etc.), bending (e.g., manual, electric or CNC hammers, disc brakes, bending machines, tube bending machines, crimping machines, special mechanical presses, etc.), assembling (e.g., by welding, soldering, brazing, crimping, coupling with adhesives, riveting, using fasteners, etc.), etc.), molding or casting (e.g., die casting, centrifugal casting, injection molding, extrusion molding, matrix molding, three-dimensional (3D) printing) technology, including melt deposition modeling, selective laser melting, selective laser sintering, composite filament manufacturing, fused filament manufacturing, stereolithography, directed energy deposition, electron beam free-form manufacturing, etc.) and PCB and / or semiconductor manufacturing technology (e.g., screen printing, photolithography, photoengraving, PCB milling, laser resist ablation, laser etching, plasma exposure, atomic layer deposition (ALD), molecular layer deposition (MLD), chemical vapor deposition (CVD), rapid thermal processing (RTP) and / or others, etc.).

[0185] The term "field of view" or "FoV" refers, at least in some embodiments, to the observable or viewable area or range at a particular location and orientation in space and / or at a given moment in time. Additionally or alternatively, the term "field of view" or "FoV" refers, at least in some embodiments, to the angular size of a viewing cone (e.g., viewing angle). Additionally or alternatively, the term "field of view" or "FoV" refers, at least in some embodiments, to the viewing angle that can be seen through an optical system.

[0186] The term "focal length" refers, at least in some embodiments, to a measure of how strongly an optical system or optical device converges or diverges light. Additionally or alternatively, the term "focal length" refers, at least in some embodiments, to the inverse of the optical power of an optical system.

[0187] The term "focal plane" refers, at least in some embodiments, to a plane passing through a focal point.

[0188] The term "focal point" refers, at least in some embodiments, to the point to which parallel input light rays are focused by an optical system or optical element.

[0189] The term "focus" refers, at least in some embodiments, to the point where light rays originating from a point on an object converge. In some embodiments, the term "focus" may be referred to as "primary focus", "focal point" or "image point".

[0190] The terms "freeform optical element" and / or "FOE" refer, at least in some embodiments, to an optical element having at least one freeform surface. Additionally or alternatively, the terms "freeform optical element" and / or "FOE" refer, at least in some embodiments, to an optical element that does not have translational or rotational symmetry about an axis perpendicular to a mean plane. Additionally or alternatively, the terms "freeform optical element" and / or "FOE" refer, at least in some embodiments, to an optical element that has a specially shaped surface that refracts an incident light beam in a predetermined manner. Relative to a diffractive optical element (DOE), a FOE has a smooth surface structure without sudden height jumps or high-frequency modulations. Similar to a classical lens, a FOE affects a light beam by refraction at its curved surface structure. The FOE refractive behavior is determined by geometric optics (e.g., ray tracing), which is different from the DOE described by a wave optics model. Rolland et al., "Freeform optics for imaging", Optica, vol. 8, pp. 161-176 (2021), is hereby incorporated by reference in its entirety.

[0191] The term "free-form surface" refers, at least in some embodiments, to a geometric element that does not have a rigid radial dimension. Additionally or alternatively, the term "free-form surface" refers, at least in some embodiments, to a surface that does not have a rotationally invariant axis. Additionally or alternatively, the term "free-form surface" refers, at least in some embodiments, to an asymmetric surface whose asymmetry goes beyond biaxial symmetry, spherical, rotationally symmetric non-spherical, off-axis conical, toroidal, and biconical. Additionally or alternatively, the term "free-form surface" refers, at least in some embodiments, to a free-form surface that can be identified by a coma shape component or a higher-order rotational variable of an orthogonal polynomial pyramid (or its equivalent). Additionally or alternatively, the term "free-form surface" refers, at least in some embodiments, to a surface of a particular shape that refracts an incident light beam in a predetermined manner. Free-form surfaces have more degrees of freedom than rotationally symmetric surfaces.

[0192] The term "front focal point" refers, at least in some embodiments, to any light ray that passes through an optical element or optical system and emerges from the optical element / system parallel to the optical axis.

[0193] The term "holographic optical element" or "HOE" refers, at least in some embodiments, to an optical element that generates a holographic image using a holographic imaging process (e.g., a mirror, a lens, a filter, a beam splitter, a directional diffuser, a diffraction grating, etc.) or a principle, such as the principle of diffraction. The shape and structure of the HOE depends on the required hardware. Coupled wave theory is a common tool for calculating diffraction efficiency or grating volume, which helps in the design of the HOE.

[0194] The term "laser" refers, at least in some embodiments, to light amplification by stimulated emission of radiation. Additionally or alternatively, the term "laser" refers, at least in some embodiments, to a device that emits light by an optical amplification process based on stimulated emission of electromagnetic radiation. As used herein, the term "laser" may refer to a device that emits laser light, the light produced by such a device, or both.

[0195] The term "lateral" refers, at least in some embodiments, to a geometric term for a position or direction extending from one side to another side. Additionally or alternatively, the term "lateral" refers, at least in some embodiments, to a direction or position relative to an object across the width of the object body, relative to a side of the object, and / or relative to movement of the object in a lateral direction.

[0196] The term "lens" refers, at least in some embodiments, to a transparent substance or material (usually glass) that is used to focus light from an object to form an image of the object. A lens is usually round in shape, with two polished surfaces, one or both of which are curved and can be convex (convex) or concave (concave). The curve is almost always spherical; that is, the radius of curvature is constant.

[0197] The term "linear" at least in some embodiments refers to a direction or position relative to an object traveling along a given path relative to the object, where the shape of the path is straight or non-straight (eg, curved, etc.).

[0198] The term "linear" at least in some embodiments refers to a direction or position relative to an object that follows a straight line relative to the object and / or refers to a motion or force that occurs along a straight line rather than a curve.

[0199] The term "longitudinal" refers, at least in some embodiments, to a geometric term for a position or direction extending the length of a body. Additionally or alternatively, the term "longitudinal" refers, at least in some embodiments, to a direction or position relative to an object spanning the length of the body of the object; relative to the top or bottom of the object, and / or relative to the object moving in an upward and / or downward direction.

[0200] The term "marginal ray" refers, at least in some embodiments, to a ray that passes through an optical system near the edge of an aperture. Additionally or alternatively, the term "marginal ray" refers, at least in some embodiments, to a ray in an optical system that begins at the point where the object intersects the optical axis and touches the edge of an aperture stop of the optical system. The term "marginal ray" may also be referred to as a "marginal axial ray" or simply a "ray."

[0201] The term "meridian ray" refers, at least in some embodiments, to a ray that is confined to a plane that includes the optical axis of the optical system and the object point from which the ray originates. The term "meridian ray" may also be referred to as a "tangential ray."

[0202] The term "mirror" refers, at least in some embodiments, to a surface of a material or substance that deflects light according to the law of reflection.

[0203] The term "monotonic" or "unidirectional" refers, at least in some embodiments, to a variable that increases or decreases and / or has no inflection point. Additionally or alternatively, the term "monotonic" or "unidirectional" refers, at least in some embodiments, to a variable that increases or decreases as a second variable increases or decreases, respectively (the relationship is not necessarily linear, but the direction does not change). Additionally or alternatively, the term "monotonically increasing" refers to a variable that increases continuously and / or a variable that increases continuously as a second variable increases.

[0204] The term "natural perspective" refers, at least in some embodiments, to the manner in which objects are depicted as they appear to the human visual system. Additionally or alternatively, the term "natural perspective" refers, at least in some embodiments, to a phenomenon in which objects farther away in a series of objects of the same size appear smaller than objects closer in the series, and conversely, objects closer appear larger, with the apparent size decreasing in proportion to the distance.

[0205] The term "normal" refers, at least in some embodiments, to a line, ray, or vector that is perpendicular to a given object. The term "normal" refers to an outward-pointing ray that is perpendicular to the surface of an optical medium and / or optical element at a given point.

[0206] The term "off-axis optical system" refers, at least in some embodiments, to an optical system in which the optical axis of the aperture does not coincide with the mechanical center of the aperture.

[0207] The term "obtain" refers, at least in some embodiments, to the action, task, operation, etc., of intercepting, moving, copying, retrieving, or acquiring (e.g., from memory, an interface, or a buffer) (partial or complete) on the original packet stream or on a copy (e.g., a new instance) of the packet stream. Other features of obtaining or receiving may involve instantiating, enabling, or controlling the ability to obtain or receive the packet stream (or the following parameters and templates or template values).

[0208] In the context of optics, the term "object" refers, at least in some embodiments, to a figure or element that is viewed or imaged through an optical system and / or can be viewed as a collection of points. For the purposes of this disclosure, in the context of optics, the term "object" can be, at least in some embodiments, a real or virtual image of an object formed by another optical system.

[0209] In the context of optics, the term “objective lens” refers, at least in some embodiments, to an optical component and / or an optical element that receives light from an object.

[0210] The terms "optical aberration" and / or "aberration" refer, at least in some embodiments, to a property of an optical system and / or optical element that causes light to be spread out over certain regions of space rather than being focused at a point. Aberrations can be defined as deviations in the performance of an optical system from a predicted performance level (or prediction for paraxial optical elements).

[0211] The term "optical axis" refers, at least in some embodiments, to a line in an optical system along which there exists a certain degree of rotational symmetry. Additionally or alternatively, the term "optical axis" refers, at least in some embodiments, to a straight line passing through the geometric center of an optical element. Light paths along the optical axis are perpendicular to the surface of the optical element. The term "optical axis" may also be referred to as a "primary axis". All other light paths passing through an optical element and its optical center (the geometric center of the optical element) may be referred to as "secondary axes". The optical axis of a lens is a straight line passing through the geometric center of the lens and connecting the two centers of curvature of its surface. The optical axis of a curved mirror passes through the geometric center of the mirror and its center of curvature.

[0212] The term "optical element" refers, at least in some embodiments, to any component, object, substance, and / or material used for, or otherwise related to, the generation and propagation of light, the changes that light undergoes and produces, and / or other phenomena related to the principles governing the image-forming properties of various devices that utilize light and / or the nature and properties of light itself. For the purposes of this disclosure, the term "optical element" refers, at least in some embodiments, to a portion of an optical system constructed or formed from one or more optical materials.

[0213] The term "optical power" refers, at least in some embodiments, to the degree to which an optical element or optical system converges or diverges light. The optical power of an optical element is equal to the reciprocal of the focal length of the device. A high optical power corresponds to a short focal length. The SI unit of optical power is the reciprocal meter (m-1), commonly referred to as diopter (or "refractive index"). The term "optical power" is sometimes referred to as optical power, refractive power, focusing power, or focusing power.

[0214] The term "optical path" refers, at least in some embodiments, to the path that light follows as it propagates through an optical medium.

[0215] The term "optical path length" refers, at least in some embodiments, to the geometric length of the optical path followed by the light and the refractive index of the medium through which the light propagates. The term "optical path length" may also be referred to as "optical distance."

[0216] The term "optical surface" (or simply "surface") refers, at least in some embodiments, to a location, area, or region of interest in an optical system and having a specific shape (curvature) and extension (aperture) in space. Additionally or alternatively, the term "optical surface" refers, at least in some embodiments, to a reflective or refractive surface that closely approximates a desired geometric surface.

[0217] The term "prism" refers, at least in some embodiments, to a transparent optical element having a flat, polished surface that can refract light. Additionally or alternatively, the term "prism" refers, at least in some embodiments, to a polyhedron comprising an n-sided polygonal base, a second base that is a translational copy (rigid translation without rotation) of the first base, and other faces connecting corresponding sides of the two bases.

[0218] The term "back focus" or "back focal point" refers, at least in some embodiments, to any light rays that enter an optical element or optical system parallel to the optical axis and are focused such that they pass through the back focal point.

[0219] The terms "rotational symmetry" and "radial symmetry" refer to the property of a shape or surface to look the same after a partial rotation. The degree of rotational symmetry of an object refers to the number of different orientations in which the object looks exactly the same each time it is rotated.

[0220] The term "sagittal plane" or "sagittal sag" refers, at least in some embodiments, to the height of a curve measured from a chord (i.e., a line segment connecting two points on the curve). Additionally or alternatively, the term "sagittal plane" or "sag" refers, at least in some embodiments, to the height or depth of an optical surface, such as an optical surface of a convex or concave lens. Additionally or alternatively, the term "sagittal plane" or "sagittal sag" refers, at least in some embodiments, to the perpendicular distance (or displacement) from the vertex of a curve of an optical surface to a plane passing through the curve of the optical surface.

[0221] The terms "stereoscopic" or "stereoscopic vision" refer, at least in some embodiments, to three-dimensional vision resulting from the spacing of the eyes, allowing the eyes to see objects from slightly different viewpoints.

[0222] The terms "stereoscopic depth of field", "stereoscopic DoF" or "SDoF" refer, at least in some embodiments, to the property or ability of a virtual image to be displayed at different distances within a field of view.

[0223] The term "stereo threshold" or "stereo threshold value" refers, at least in some embodiments, to the minimum relative binocular disparity that produces depth perception.

[0224] The term "slope" refers, at least in some embodiments, to the steepness or inclination of a surface.

[0225] The term "signal" refers, at least in some embodiments, to an observable change in quality and / or quantity. Additionally or alternatively, the term "signal" refers, at least in some embodiments, to a function that carries information about an object, event, or phenomenon. Additionally or alternatively, the term "signal" refers, at least in some embodiments, to any time-varying voltage, current, or electromagnetic wave that may or may not carry information. The term "digital signal" refers, at least in some embodiments, to a signal constructed from a set of discrete waveforms of a physical quantity to represent a sequence of discrete values.

[0226] The term "spherical" refers, at least in some embodiments, to an object having a shape similar to or substantially similar to a sphere. A "sphere" is the set of all points in three-dimensional space that are the same distance (radius) from a given point (center), or the result of rotating a circle about one of its diameters.

[0227] The term "substrate" refers, at least in some embodiments, to a supporting material on which or in which components of a semiconductor device are fabricated or attached. Additionally or alternatively, the term "substrate of a thin film integrated circuit" refers, at least in some embodiments, to a piece of material that forms a supporting base for thin film circuit components and possible additional components. Additionally or alternatively, the term "substrate of a flip chip die" refers, at least in some embodiments, to a supporting material on which one or more semiconductor flip chips are attached. Additionally or alternatively, the term "original substrate" refers, at least in some embodiments, to the original semiconductor material being processed. The original material can be a layer of semiconductor material cut from a single crystal, a layer of semiconductor material deposited on a supporting substrate, or the supporting substrate itself. Additionally or alternatively, the term "remaining substrate" refers, at least in some embodiments, to a portion of the original material that remains substantially unchanged when device components are formed on or in the original material.

[0228] The term "surface" refers, at least in some embodiments, to the outermost or uppermost layer of a physical object or space.

[0229] The term "annular" refers, at least in some embodiments, to an object having a shape that is or is substantially similar to a torus. A "torus" is a surface of revolution produced by rotating a circle in three-dimensional space about an axis that is coplanar with the circle.

[0230] The term "vergence" refers, at least in some embodiments, to the angle formed by light rays that are not completely parallel to each other. Additionally or alternatively, the term "vergence" refers, at least in some embodiments, to the curvature of an optical wavefront. The terms "convergence," "convergence," and "convergent" refer to light rays approaching an optical axis as they propagate. Additionally or alternatively, the terms "convergence," "convergence," and "convergent" refer to wavefronts that propagate toward a single point and / or produce a wavefront that has positive convergence. The terms "divergence," "divergence," and "divergent" refer to light rays that propagate away from an optical axis as they propagate. Additionally or alternatively, the terms "divergence," "divergence," and "divergent" refer to wavefronts that propagate away from a single source point and / or produce a wavefront that has negative convergence. Typically, convex lenses and concave mirrors converge parallel light rays, while concave lenses and convex mirrors diverge parallel light rays.

[0231] The term "visual ergonomics" refers, at least in some embodiments, to the theory, knowledge, design, engineering, and / or evaluation of systems involving human visual processes and / or the interaction of human visual processes with other components of the system. Visual ergonomics generally involves designing, engineering, and / or evaluating systems by optimizing human well-being and overall system performance, and may include aspects such as the visual environment (e.g., lighting, etc.), visually demanding tasks, visual function and performance, visual comfort and safety, optical correction and other tasks and / or assistive tools, etc.

[0232] The foregoing detailed description refers to the accompanying drawings, which show by way of example embodiments that may be implemented. The same reference numerals may be used in different figures to identify the same or similar elements. Various operations may be described sequentially as multiple discrete operations to aid in understanding the embodiments; however, the order of description should not be interpreted as implying that the operations have sequential dependencies. The present disclosure may use perspective-based descriptions, such as up / down, back / front, top / bottom, etc. These descriptions are only for ease of understanding and are not intended to limit the present application to the disclosed embodiments.

[0233] The foregoing description of one or more implementations provides illustrations and descriptions of various exemplary embodiments, but is not intended to be exhaustive or to limit the scope of the embodiments to the precise form disclosed. Modifications and variations may be made in accordance with the foregoing teachings, or may be derived from the practice of the various embodiments. Where specific details are set forth to describe features of the present disclosure, it should be apparent to one skilled in the art that the present disclosure may be practiced without these specific details, or with variations of these specific details. Therefore, the present disclosure should be considered illustrative rather than restrictive.

Claims

1. An optical system comprising: Combiner; a picture generation unit (PGU) configured to project light toward the combiner; and A corrective optical assembly is disposed between the PGU and the combiner, wherein the corrective optical assembly includes at least one rotationally asymmetric optical surface arranged to form a virtual image surface (VIS) by generating an optical path having an optical path length that increases monotonically in a horizontal direction from a vertex, whose vertex specifies a horizontal field of view (HFoV) of light rays propagating from the PGU to the combiner through the corrective optical assembly toward an observer, so that the optical system provides a stereoscopic depth of field (SDoF) for displaying virtual objects at different distances from the observer.

2. The optical system of claim 1, wherein the monotonically increasing optical path length increases monotonically from a center point of a field of view (FoV) in a direction of the HFoV.

3. The optical system of claim 2, wherein a first angle between a first chief ray and a normal to the VIS is less than a second angle between a second chief ray and the normal to the VIS, wherein the first chief ray is closer to a center of the FoV than the second chief ray, and wherein both the first and second chief rays are aimed in the direction of the HFoV.

4. The optical system of claim 1, wherein the VIS has a cylindrical shape with a convex side facing the observer, and the cylindrical shape has a directrix which is a continuous curve extending in the direction of the HFoV.

5. The optical system of claim 1, wherein the combiner comprises a holographic optical element (HOE) having positive optical power.

6. The optical system of claim 5, wherein the optical power of the HOE is between 1.1 and 6.6 diopters.

7. The optical system of claim 1, wherein the corrective optical assembly comprises at least one optical element, and the at least one optical element comprises a plurality of surfaces.

8. An optical system as described in claim 7, wherein the multiple surfaces are formed into a three-dimensional shape including the at least one rotationally asymmetric optical surface and one or more additional optical surfaces, wherein each of the one or more additional optical surfaces is selected from the group consisting of a plane, a sphere, an asphericity, a cylinder, a ring, a biconic, and a free shape.

9. The optical system of claim 7, wherein the at least one optical element is a prism, the plurality of surfaces include at least two refractive optical surfaces and at least one reflective optical surface, and the at least one optical element is formed such that the at least one reflective optical surface is disposed between respective refractive optical surfaces of the at least two refractive optical surfaces.

10. The optical system of claim 9, wherein the at least one rotationally asymmetric optical surface is one of the at least two refractive optical surfaces.

11. The optical system of claim 9, wherein a first surface of the at least two refractive optical surfaces is a spherical surface, an aspherical surface, a biconical surface, or a free-form surface; and a second surface of the at least two refractive optical surfaces is a spherical surface, an aspherical surface, a biconical surface, or a free-form surface.

12. The optical system of claim 9, wherein the at least one reflective optical surface is a plane, a spherical surface, an aspherical surface, a cylindrical surface, a toroidal surface, a biconical surface, or a free-form surface.

13. The optical system of claim 9, wherein each of the at least two refractive optical surfaces is a free-form optical surface and the at least one reflective optical surface is a planar optical surface.

14. The optical system of claim 1, wherein the optical system is or is included in an augmented reality (AR) heads-up display (HUD) device with improved visual ergonomics.

15. An optical system for an augmented reality (AR) head-up display (HUD) device with improved visual ergonomics, the optical system comprising: a combiner including a holographic optical element (HOE) having a positive optical power; a picture generation unit (PGU) configured to project light toward the combiner; and a corrective optical assembly disposed between the PGU and the combiner, wherein the corrective optical assembly comprises at least one rotationally asymmetric optical surface arranged to provide a stereoscopic depth of field (SDoF) by generating a monotonically increasing optical path along a horizontal field of view (HFoV) for light rays propagating from the PGU to the combiner, such that the optical system displays virtual objects at different distances from an observer.

16. The optical system of claim 15, wherein the monotonically increasing optical path increases monotonically from a center point of a field of view (FoV) in a direction of the HFoV.

17. The optical system of claim 15, wherein the at least one rotationally asymmetric optical surface is configured to form a curved virtual image surface (VIS) based on light rays propagating from the PGU, and wherein the curved VIS has a cylindrical shape, a vertex of the curved VIS is pointed toward an observer, and a directrix of the curved VIS is a continuous curve extending in the HFoV direction.

18. The optical system of claim 17, wherein the corrective optical assembly comprises at least one optical element, and the at least one optical element comprises at least two refractive optical surfaces and at least one reflective optical surface.

19. The optical system of claim 18, wherein the at least one optical element is formed to have a prism shape, and the at least one reflective optical surface is disposed between respective refractive optical surfaces of the at least two refractive optical surfaces.

20. The optical system of claim 18, wherein the at least one rotationally asymmetric optical surface is one of the at least two refractive optical surfaces, and the other of the at least two refractive optical surfaces is one of a flat or planar surface, a spherical surface, an aspherical surface, a cylindrical surface, a toroidal surface, a biconical surface, or a free-form surface, and wherein the at least one reflective optical surface is one of a planar surface, a spherical surface, an aspherical surface, a cylindrical surface, a toroidal surface, a biconical surface, or a free-form surface.

21. The optical system of claim 18, wherein each of the at least two refractive optical surfaces is a free-form optical surface and the at least one reflective optical surface is a planar optical surface.

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