Head-mounted augmented reality systems, devices, and apparatuses

Abstract

An augmented reality device includes two optical combiners configured to correspond to two eyes of a user, each of the two optical combiners including an inner surface for reflecting light from an image source to a respective eye of the user, wherein the inner surface is a freeform surface having a surface function based on an XY polynomial including at least one multinomial; an image source positioned above the eyes of the user for emitting light to the optical combiners, wherein the image source includes two active display areas positioned on two different planes; and a housing structure configured to maintain relative positions and orientations of the optical combiners and the image source.

Description

[0001] Related applications

[0002] This application is based on and claims priority to provisional patent application No. 62 / 864,347, filed on June 20, 2019, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This invention generally relates to augmented reality systems, devices, and equipment. Background Technology

[0004] Augmented reality (AR) is achieved by displaying computer-generated images (also known as computer-generated content, virtual content, or virtual images) over a real image observed by a viewer. In video-transparent (VST) augmented reality, a real image is first captured by an imaging device (e.g., a smartphone camera); then, computer-generated content is rendered over the captured real image; finally, the rendered image is viewed on a physical display medium (e.g., a smartphone or tablet screen). In optically transparent (OST) augmented reality, light from the real world passes through an optical medium in which the light combines with computer-generated image content, allowing the viewer to simultaneously receive the combined content. This disclosure includes a head-mounted OST AR system. Summary of the Invention

[0005] Various embodiments described herein include, but are not limited to, systems, devices, and apparatuses for providing augmented reality, including head-mounted augmented reality devices.

[0006] In various embodiments, the augmented reality device may include two optical combiners, an image source, and a housing structure. In some embodiments, the two optical combiners are configured to correspond to the user's two eyes respectively, each of the two optical combiners including an inner surface for reflecting light from the image source to the user's respective eye and an outer surface for allowing light from the real world to enter the respective optical combiner, wherein the inner surface is a free surface having a surface function based on an XY polynomial comprising at least one multivariate monomial.

[0007] In some embodiments, the image source is located above the user's eyes and is configured to emit light onto the inner surfaces of two optical combiners, wherein the image source includes two active display areas located on two different planes.

[0008] In some embodiments, the housing structure is configured to maintain the relative position and orientation of the two optical combiners and the image source.

[0009] In some embodiments, the image source includes two independent display panels, and each of the two active display areas is a portion or all of a corresponding one of the two independent display panels; and each independent display panel is associated with a corresponding one of the two optical combiners.

[0010] In some embodiments, each display panel is at an angle about an orthogonal axis perpendicular to the respective display panel.

[0011] In some embodiments, each of the two active display areas is angled about the vertical axis, the absolute value of the angle being between 0 and 45 degrees. In some embodiments, each active display area is angled about a reference plane formed by the horizontal and vertical axes, the value of the angle being between 45 and 90 degrees.

[0012] In some embodiments, each active display area is angled about the vertical axis, the absolute value of which is between 0 degrees and 45 degrees.

[0013] In some embodiments, the image source includes a liquid crystal display, a micro LED display, an organic light-emitting diode display, or an active matrix organic light-emitting diode display.

[0014] In some embodiments, the inner surface is coated with a partially reflective and partially transmissive layer; the outer surface is coated with an anti-reflective layer; each of the two optical combiners further includes a semi-transparent substrate located between the inner surface and the outer surface.

[0015] In some embodiments, the surface function has parameters including vertex curvature, quadratic curve constant, and constants associated with a multivariate monomial, wherein all parameters are nonzero.

[0016] In some embodiments, the surface function of the outer surface of each of the two optical combiners is optimized by ray tracing based on the surface function of the inner surface and the refractive index of the corresponding optical combiner.

[0017] In some embodiments, the image source includes a foldable display having one or more fold lines dividing the display into two or more portions, each of which includes an active display area. In some embodiments, one of the fold lines forms an angle with a reference plane formed by the longitudinal and horizontal directions passing through the user's head, and the value of the angle is between 0 degrees and 90 degrees. In some embodiments, the rear surfaces of two adjacent portions form a fold angle, the value of which is between 180 and 90 degrees.

[0018] In some embodiments, the two active display areas are curved. In some embodiments, each curved display area has a cylindrical surface profile, a conical surface profile, a double-conical surface profile, an annular surface profile, a surface profile described by a Zernike polynomial, a surface profile described by an XY polynomial, a Bezier surface profile, or a B-spline surface profile.

[0019] In some embodiments, the housing structure further includes a headband configured to maintain the position and orientation of the two optical combiners and the image source relative to the user's head.

[0020] In some embodiments, the housing structure includes an optical clamp configured to allow each of the two optical combiners to: rotate about a horizontal axis to maintain a rotatable position, reflect light to the user's corresponding eye, or hide the enhanced image from the user's corresponding eye. In some embodiments, the housing structure includes an optical clamp configured to allow each of the two optical combiners to detach from the housing structure. In some embodiments, the housing structure further includes a thin-film light valve that controls the transparency level of the substrate of each of the two optical combiners.

[0021] In some embodiments, the augmented reality device further includes: a computing device connected to an image source, the computing device being configured to generate an image presented by the image source on the inner surfaces of two optical combiners; and a power source configured to provide power to the image source and the computing device.

[0022] In various embodiments, a head-mounted augmented reality device may include: an optical combiner located in front of a user's eyes, including an inner surface, wherein the inner surface is a free surface having a surface function based on an XY polynomial including at least one multivariate monomial; an image source located above the user's eyes and positioned longitudinally between the eye position and the optical combiner, the image source being configured to emit light toward the inner surface of the optical combiner, wherein the image source includes an active display area angled about a vertical axis passing through the user's head, the absolute value of the angle being between 0 degrees and 45 degrees; and a housing structure configured to maintain the relative position and orientation of the optical combiner and the image source.

[0023] These and other features of the systems, devices, and apparatuses disclosed herein will become more apparent when considering the following description and appended claims, all of which form part of this document, wherein like reference numerals denote corresponding portions in the respective figures. However, it should be clearly understood that the figures are for illustrative and descriptive purposes only and are not intended to be limiting of the invention. It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and do not limit the invention as described in the claims. Attached Figure Description

[0024] The preferred and non-limiting embodiments of the present invention can be more readily understood by referring to the accompanying drawings, in which:

[0025] Figure 1 An exemplary head-mounted augmented reality system is shown.

[0026] Figure 2 A side cross-sectional view of a combiner according to various embodiments of the present disclosure is shown.

[0027] Figure 3 The RMS spot size of augmented reality systems according to various embodiments of this disclosure is shown.

[0028] Figure 4 The image grid is distorted.

[0029] Figure 5A and Figure 5B Reference planes and angles for the relative placement of one or more display panels according to various embodiments of this disclosure are shown.

[0030] Figure 6A and Figure 6B A top cross-sectional view of a display and optical combiner according to various embodiments of the present disclosure is shown.

[0031] Figure 7A and Figure 7B Display placement relative to a third axis according to various embodiments of the present disclosure is shown.

[0032] Figure 8 A folding display with a single folding line is shown according to various embodiments of the present disclosure.

[0033] Figure 9 A folding display with three fold lines is shown according to various embodiments of the present disclosure.

[0034] Figure 10A and Figure 10B A single-curved surface display according to various embodiments of the present disclosure is shown.

[0035] Figure 11 Hyperbolic displays according to various embodiments of the present disclosure are shown. Detailed Implementation

[0036] Specific non-limiting embodiments of the invention will now be described with reference to the accompanying drawings. It should be understood that specific features and aspects of any embodiment disclosed herein may be used and / or combined with specific features and aspects of any other embodiment disclosed herein. It should also be understood that these embodiments are by way of example and are merely illustrative of a small number of embodiments within the scope of the invention. Various changes and modifications that will be apparent to those skilled in the art are considered to be within the spirit, scope, and concept of the invention as further defined in the appended claims.

[0037] OST AR headphones offer a large field of view (FOV) for their wearers with a lightweight and compact form factor. Off-axis optics can be composed of freeform surfaces to achieve a large FOV within a relatively compact headphone form factor. A major design challenge in augmented reality engineering is providing a large FOV without the severely degraded image quality typically found in off-axis optics outside the central region of the FOV. This disclosure includes using an XY polynomial with multivariate monomials as a surface function of the freeform surface to achieve a large FOV with high image quality and uniformity across the entire field of view. This disclosure provides a binocular FOV greater than 50 degrees vertically and greater than 90 degrees horizontally.

[0038] In some embodiments, the OST AR headset may include two optical combiners, an image source, a computing device, a power supply, and a housing structure. Each optical combiner may be located in front of one of the wearer's eyes and includes most of the AR FOV coverage of the human eye's field of view. The OST-AR headset may also include a partially reflective layer applied to one or more substrate surfaces of each or one of the optical combiners. The partially reflective layer may reflect light from the image source into the wearer's eye while also allowing light from the real world to pass through the combiner, such that light from the image source and light from the real world can reach the wearer's eye simultaneously. The optical combiners may form a symmetrical pair with respect to a vertical reference plane formed by the vertical and longitudinal axes from the center of the wearer's head. The image source may be located above the wearer's eyes, facing away from the wearer's head, and positioned longitudinally between the eye position and the optical combiner. The image source may include one or more foldable or formable display panels. Each panel or a portion of each panel may project a computer-generated image onto each of the wearer's eyes. The computing device may be functionally connected or communicatively coupled to the image source and generate an image for projection from the image source.

[0039] Figure 1An exemplary head-mounted augmented reality system 100 is illustrated. The head-mounted augmented reality system 100 includes a first optical combiner 110, a second optical combiner 120, an electronic chamber 130, and a headband 140. In some embodiments, the head-mounted augmented reality system has only one optical combiner. The optical combiners 110 and 120 of the head-mounted augmented reality system 100 may each include a substrate, an inner surface, and an outer surface. The substrate may be transparent. In some embodiments, the transparency of the substrate may be variably adjusted. The inner and / or outer surfaces of the optical combiners 110 and 120 may be freeform surfaces.

[0040] In some embodiments, the optical combiners 110, 120 can be arranged in a compact manner such that for the optical components in the smaller longitudinal dimension, the longitudinal eye relief is less than 5.5 cm but greater than 2 cm, to provide sufficient space to accommodate vision correction or safety glasses worn by the user.

[0041] Electronic compartment 130 may include a power supply and a computing device. The computing device may be functionally connected to or communicatively coupled to an image source to implement one or more programs and provide computer-generated images. In some embodiments, the computing device may include a system-on-a-chip (SoC) integrating a central processing unit, memory, auxiliary memory, and input / output ports. The SoC may also include a graphics processing unit. In some embodiments, the computer-generated images are stereoscopic images rendered from two perspectives in a three-dimensional scene, such that the stereoscopic images create a three-dimensional perception when viewed by a wearer. In some embodiments, the computing device may also include a wireless connectivity module providing wireless connectivity capabilities such as Wi-Fi, Bluetooth, and cellular networks. Furthermore, the computing device may be functionally connected to a power source. The power source may include one or more batteries. In some embodiments, the power source may be a rechargeable lithium-ion battery.

[0042] The headband 140 can be used to position or secure the head-mounted augmented reality system 100 to the wearer's head. In some embodiments, the headband 140 can be adjustable.

[0043] The head-mounted augmented reality system 100 may also include an optical clamp, a display clamp, and / or one or more thin-film light valves. The optical clamp may be rigidly connected to the optical combiners 110, 120 and maintain the relative position and orientation of the optical combiners 110, 120 relative to the image source within design tolerances. In some embodiments, the optical clamp may be allowed to rotate about a horizontal axis to lift the optical combiners 110, 120 upwards and switch between augmented reality mode and non-interference mode. In augmented reality mode, the optical combiners 110, 120 are held in a designed position to reflect light into the wearer's eyes. In non-interference mode, the optical combiners 110, 120 are held outside the wearer's natural field of vision, thus hiding the augmented image from the wearer. In some embodiments, the optics may include a detachable structure such that, in the event of damage to the optical combiners 110, 120 or the optics themselves, the components of the optical combiners 110, 120 and the optics can be detached from the housing structure that holds the head-mounted augmented reality system 100 together and replaced with new components.

[0044] The display device can be rigidly connected to the image source, maintaining the position and orientation of the image source within design tolerances. The image source can provide a computer-generated image to the wearer by projecting light onto the inner surfaces of the optical combiners 110, 120. The image source may include one or more display panels located between the optical combiners 110, 120 and the headband 140. The display panels may include, for example, liquid crystal displays, micro LED displays, organic light-emitting diode displays, or active-matrix organic light-emitting diode displays.

[0045] In some embodiments, the image source may include two separate flat display panels, each positioned above the wearer's eyes and facing outwards from the wearer. Each display panel may be further arranged such that light emitted from the display is reflected by the inner surface of the respective optical combiner 110, 120 to the respective eye to form a virtual image. Each display panel may also include an active display area such that light emitted from pixels within this area is reflected to form a virtual image within a defined field of view.

[0046] One or more thin-film light valves may be included in the head-mounted augmented reality system 100 to actively control the transparency of one or more of the optical combiners 110, 120, and may be functionally connected to a computing device. Each thin-film light valve may be positioned behind the respective optical combiner 110, 120 and longitudinally (orthogonal to the horizontal and vertical directions) away from the wearer's eyes. Furthermore, the thin-film light valve may be positioned in the optical path of the real image within a defined field of view to actively adjust the amount of real light allowed to reach the wearer's eyes based on ambient light intensity. In some embodiments, the thin-film light valve may be a liquid crystal light valve. Real light passing through the liquid crystal light valve may first pass through a first filter polarizing the real light in one direction, and then through a second filter filled with liquid crystal. By controlling the voltage applied to the second filter, light of different intensities can be produced.

[0047] Figure 2 A side cross-sectional view of a combiner 200 according to various embodiments of the present disclosure is shown. In some embodiments, the combiner 200 may be implemented in an augmented reality system, such as... Figure 1 A head-mounted augmented reality system 100. As shown in the figure, the combiner 200 includes a substrate 210, an inner surface 220, and an outer surface 230.

[0048] The inner surface 220 is concave and faces the wearer's eye. The outer surface 230 is convex and is located behind the first surface and positioned away from the wearer's eye. In some embodiments, the substrate 210 can be any translucent material, such as glass or a polymer, such as PMMA or polycarbonate. The inner surface 220 can reflect light from the image source to the wearer's eye and magnify the image. In some embodiments, a partially reflective and partially transmissive coating is applied to the inner surface 220. In some embodiments, an antireflective coating is applied to the outer surface 230 to reduce unwanted double images caused by reflections of light from the image source on the outer surface 230. The geometry within the optically transparent apertures of the inner and outer surfaces 220 and 230 can be further defined in a local coordinate system by a surface function comprising an XY polynomial added to the base conic section. One form of this surface function is shown below:

[0049]

[0050] In this equation, z is the concavity of the surface parallel to the z-axis, c is the vertex curvature, k is the conic constant, r equals √(x^2+y^2), and c j It is the j-th monomial x m y n The coefficients, where the exponents m and n are non-negative integers. Furthermore, the surface function according to this disclosure may contain at least one multivariable monomial c. j x m yn It has a non-zero coefficient c j The positive exponents m and n are included. Including multivariable monomials allows for additional degrees of freedom, enabling many potential advantages such as reduced optical aberrations and miniaturization of the entire system. Higher-order monomials can add more degrees of freedom to the optical system, significantly improving image quality outside the central portion of the field of view. In some embodiments, higher-order monomials can be removed from the surface function to reduce the complexity of the surface geometry and achieve lower manufacturing costs. The surface function of the inner surface 220 can be optimized to minimize the root-mean-square spot size of the optical design to correct off-axis aberrations in the virtual image.

[0051] Figure 3 The RMS spot size 340 of the augmented reality system 300 is shown. The augmented reality system 300 includes an inner surface 310 and an image source 320. The inner surface 310 may be the inner surface of an optical compiler. The image source 320 may be one or more displays.

[0052] The design of the optical surface geometry according to this disclosure can be formulated as an optical system optimization problem based on real ray tracing. During ray tracing in the optical system of this disclosure, a beam of light emitted from a sampling point on an image source 320 is simulated (tracked). The light is reflected by the inner surface 310 and enters the pupil at an angle within the field of view (FOV). The reflected light has corresponding hypothetical opposite rays converging on a virtual image plane 330. The RMS spot size 340 of each converging beam reflects the image quality of the corresponding local spot observed by the user (wearer) on the virtual image plane 330. Image quality can be improved by reducing the RMS spot size 340. In implementation, the error function, as a single positive number including weighted image errors, can be adjusted by adjusting parameters of the optical system, including c, k, c j The position and orientation of the local coordinate system of the surface function relative to the pupil, and the position and orientation of the image source 320 relative to the pupil, are defined and minimized. When the error function is minimized, the RMS spot size 340 is minimized.

[0053] Table 1 below provides RMS spot sizes for different optical surface profiles, allowing for a comparison of image quality for a first optical surface design using different surface profiles. The surface profiles in this table are common types typically used in optical lens designs and include, for example, aspherical, Zernike polynomial, XY polynomial (excluding multivariate mononomials), and XY polynomial (including multivariate mononomials). Table 1 provides RMS spot sizes sampled in a left-eye scene, where the beam enters the pupil on the horizontal plane from three angles (fields): -20°, 0°, and 40°. Neither the aspherical nor the Zernike design achieved a 40° field due to insufficient light power. While both XY polynomial designs achieved a wide field of view, the design including multivariate mononomials significantly improved the RMS spot size (and image quality) across all fields of view.

[0054] Table 1. RMS spot sizes for different optical surface profiles

[0055] RMS spot size (mm) 0° -20° 40° XY - a polynomial with multivariate monomials 0.61571 0.23522 0.43646 XY - a polynomial without multivariate monomials 1.3540 0.45230 0.96477 Zernike polynomials 1.3147 0.96568 N / A aspherical 1.0762 1.2398 N / A

[0056] Figure 4 A distorted image grid 400 is shown. When real light enters the optical combiner through the outer surface, it is transmitted through the substrate and exits at the inner surface. In the optical path, the light is refracted twice, causing distortion of the real image perceived by the wearer. The surface function of the outer surface can be optimized using real ray tracing, and based on the design of the inner surface and the refractive index of the combiner material, the difference between the light beams passing through the optical combiner and those not passing through the optical combiner in the real world within the field of view is minimized. Figure 4 In this context, the distorted image grid 400 includes a perceived image that overlays the real image. Solid lines represent the real image, while dashed lines represent the perceived image that the wearer can observe over the real image through the optical combiner without the aforementioned design optimizations to minimize distortion of the real image.

[0057] Figure 5A and Figure 5B Reference planes and angles for the relative placement of one or more display panels according to various embodiments of the present disclosure are shown. The reference planes and angles can be implemented by selecting a particular orientation and / or position for one or more display panels. As shown in the figures, Figure 5A It includes two displays 510, a lower edge 515, a first angle 520, a first reference line 525 parallel to the vertical axis passing through the center of the wearer's head, and a second reference line 535 parallel to the horizontal axis passing through the center of the wearer's head. (See figure.) Figure 5B Includes display 550, bottom edge 560, and second angle 570.

[0058] In some embodiments, the two displays 510 constitute the image source of the AR system, such as Figure 1 A head-mounted augmented reality system 100. For example... Figure 5A As shown, the two displays 510 can be located in two different planes. For example, the two displays 510 are not coplanar. Furthermore, each of the two displays 510 can be arranged relative to a first reference plane formed by a first reference line 525 and a second reference line 535. Each of the two displays 510 can be planar, or can be oriented based on rotation about a horizontal axis passing through the center of the wearer's head, a vertical axis passing through the center of the wearer's head, a longitudinal axis passing through the center of the wearer's head, a horizontal axis parallel to the horizontal axis passing through the center of the wearer's head, a vertical axis parallel to the vertical axis passing through the center of the wearer's head, and / or a longitudinal axis parallel to the longitudinal axis passing through the center of the wearer's head. Figure 5A The vertical axis, horizontal axis, and vertical axis shown may not necessarily be aligned with the vertical axis. Figure 5B The same as in [the previous sentence]. Figure 5A and Figure 5B The axes of the coordinate system in the image can be parallel to each other, but can pass through different origins. For example, as shown in the image... Figure 5B As shown, display 550 can be tilted about a vertical axis passing through the vertex of display 550. The active display area in each of the two displays 510 can be a portion or all of each display. Each of the two displays 510 has a lower edge 515 coinciding with a first reference plane. The display surface is arranged such that the display surface forms a first angle 520 with the first reference plane at the lower edge 515. In some embodiments, the first angle 520 can be greater than 45 degrees and less than 90 degrees to achieve a smaller display longitudinal footprint.

[0059] like Figure 5B As shown, display 550 may include one of two displays 510, or may include different displays. Display 550 is further arranged such that its lower edge 560 and the horizontal axis form a second angle 570 in a second reference plane formed by the horizontal and vertical axes, and the second angle 570 is greater than -45 degrees (i.e., negative 45 degrees) and less than 45 degrees. Therefore, the system has additional degrees of freedom to improve image quality. The origin of the coordinate system formed by the horizontal, vertical, and vertical axes (not shown) may be the vertex of display 550, which may be located at a certain distance (e.g., 1 inch, 1.5 inches, 2 inches, etc.) from the center of the wearer's head.

[0060] Figure 6A and Figure 6BA top cross-sectional view of a display 610 and an optical combiner 620 according to various embodiments of the present disclosure is shown. As shown, the optical combiner 620 has a first local curvature 635 and a second local curvature 640 corresponding to the outward field of view and the inward field of view, respectively. Figure 6A As shown, the optical combiner 620 is spaced apart from the display 610 by a first distance 625 and a second distance 630. Figure 6B As shown, the optical combiner 620 is spaced apart from the display 610 by a third distance 650 and a fourth distance 655. As shown in the figure, in Figure 6A and Figure 6B Between these points, the display 610 is rotated about the vertical axis by an angle 670, resulting in the third distance 650 being closer in magnitude to the fourth distance 655 than the first distance 625 is closer to the second distance 630. In some embodiments, the minimum distance between the display 610 and the first local curvature 635 can be set based on the angle 670 to be equal to the minimum distance between the display 610 and the second local curvature 640.

[0061] Due to the asymmetry of the human field of view for each eye, the design of large field-of-view optical systems typically distributes the field of view for each eye asymmetrically. For example, the horizontally inward field of view (from the vertical meridian of each eye toward the nose) is smaller than the horizontally outward field of view (from the vertical meridian of each eye toward time). Therefore, when the lower edge of the display coincides with the horizontal axis, the local optical system corresponding to the outer field of view has a shorter object distance than that of the inner field of view. Consequently, the first local curvature 635 corresponding to the outer field of view may require greater optical power to form a virtual image on the image plane compared to the second local curvature 640 corresponding to the inner field. By introducing angle 670, the additional degree of freedom can potentially alleviate the constraints on the first local curvature 635 and thus provide improved image quality.

[0062] Table 2 below shows the RMS spot size of the system with or without an angle of 670°. The results of the RMS spot size show that the image quality is significantly improved by introducing an angle of 670° into the positioning of the display 610.

[0063] Table 2. Comparison of RMS spot size between display positions with and without rotation.

[0064] Light spot diagram RMS (mm) 0° -25° 45° average No rotation 0.69203 0.86912 0.67302 0.744723 With rotation 0.57108 0.77305 0.4182 0.587443

[0065] Figure 7A and Figure 7B The arrangement of a display 710 relative to a third axis 620 is shown according to various embodiments of the present disclosure. Figure 7A Includes an ideal active display area 630 associated with the virtual image 615, which extends beyond the display 610 at an extended location 635.

[0066] like Figure 7A and Figure 7B As shown, the display 710 can rotate to a third angle of 650 degrees—attached to or replacing... Figure 5A , Figure 5B , Figure 6A and Figure 6B The rotation refers to an orthogonal axis 620 perpendicular to the surface of display 610. Due to the off-axis nature of the proposed optical system, the image displayed on display 610 may be distorted when reflected by the inner surface of optical combiner 625. Therefore, the ideal active display area corresponding to the undistorted virtual image in the defined field of view can be an irregular shape located on the plane of display 610 but extending beyond its boundaries. To accommodate this, display 610 is rotated by a third angle 650 to include the shape of the ideal active display area within display 610.

[0067] Figure 8 A foldable display 800 having a single fold line 810 is illustrated according to various embodiments of the present disclosure. In some embodiments, the foldable display 800 may be referred to as a "foldable display". In some embodiments, the foldable display 800 may include multiple fold lines that do not intersect each other within the physical boundaries of the foldable display 800. The foldable display 800 may include one or more active display areas. In some embodiments, the foldable display 800 is arranged in an augmented reality system such that the active display area faces outward in the longitudinal direction and away from the wearer's head. In some embodiments, the foldable display 800 may be implemented in an augmented reality system, such as... Figure 1 A head-mounted augmented reality system 100. The active display area can emit light reflected from the inner surface of a corresponding optical combiner and enter the wearer's corresponding eye to form a whole virtual image or a part of a virtual image within the defined field of view of that eye.

[0068] In some embodiments, the foldable display 800 may have a single fold line 810 dividing the display into two parts. The single fold line 810 may form a first angle 820 with a first reference plane formed by longitudinal and horizontal directions. The first angle 820 (in degrees) may be any angle greater than 0° and less than 90°. The single fold line 810 may also coincide with a second reference plane formed by longitudinal and vertical directions. Each of the two parts of the foldable display 800 also has a rear surface located on opposite sides of the surface containing the active display area. The two parts of the foldable display 800 may form a second angle 830 at the fold line. The second angle 830 may be any angle less than 180° and greater than 0°. In some embodiments, the two parts of the foldable display 800 are curved. The surface profile of the active display area in each of the two curved parts may be of various forms, including but not limited to cylindrical surfaces, conical surfaces, Bezier surfaces, and B-spline surfaces.

[0069] Figure 9 A folding display 900 with three fold lines 910 is shown according to various embodiments of the present disclosure.

[0070] Folding lines 910 divide the foldable display 900 into N+1 sections, where N is the number of folding lines. Each section also has a rear surface located on the opposite side of the surface containing the active display area. In some embodiments, these sections are non-planar; therefore, every two adjacent rear surfaces form a folding angle 920 at a shared folding line, and each folding angle 920 (in degrees) can be any degree less than 180° and greater than 90°. In some embodiments, these sections are curved. The surface profile of the active display area in each curved section can be of various forms, including but not limited to cylindrical surfaces, conical surfaces, Bézier surfaces, and B-spline surfaces.

[0071] Figure 10A and Figure 10B A single-curved display 1000, 1050 according to various embodiments of the present disclosure is illustrated. In some embodiments, one or more of the single-curved displays 1000, 1050 may be implemented as an augmented reality system (e.g., Figure 1 The image source in the head-mounted augmented reality system 100. As shown in the figure. Figure 10A The system includes a single-curved display 1000, which comprises a first axis 1010, a first angle 1020, and a basic curve 1030. (See figure.) Figure 10B It includes a single-curved display 1050, which includes a second axis 1060, a second angle 1070, a first radius 1080, and a basic curve 1090.

[0072] In some embodiments, one of the curved displays 1000, 1050 can be integrated into the augmented reality system and has an image display surface arranged longitudinally outward away from the wearer's head. The image display surface may also include at least one active display area, such that light emitted by pixels within each of one or more active display areas is reflected by the corresponding inner surface of the optical combiner to form a virtual image within the defined field of view of the corresponding eye. By having a curved display surface, the optical system can have additional degrees of freedom, allowing the position of the local display area to be optimized for the corresponding local optics. As a result, this design can further reduce the light power requirements on the local curvature of the inner surface of the optical combiner and achieve better image quality across the entire defined field of view. The surface profile of the active display area included within a single curved display 1000, 1050 can be of various forms defined in a local coordinate system. For example, the surface profile can be a portion of a cylindrical surface, a portion of a conical surface, a portion of a double-conical surface, a portion of a toroidal surface, a portion of a surface described by a Zernike polynomial, a portion of a surface described by an XY polynomial, a portion of a Bezier surface, or a portion of a B-spline surface.

[0073] like Figure 10A As shown, the single-curved display 1000 constitutes an image source and has two active display areas divided by a first axis 1010. Each active display area can emit light reflected by a corresponding optical combiner to a corresponding eye. The surface profile of the surface within each active display area can be, for example, a cylindrical surface formed by sliding a basic curve along the first axis 1010. The first axis 1010 can further coincide with a vertical reference plane formed by a vertical direction and a longitudinal direction, and further form a first angle 1020 with the longitudinal direction. The first angle 1020 (in degrees) can be any angle greater than 0° and less than 90°.

[0074] like Figure 10B As shown, a single-curved display 1050 constitutes an image source and has two active display areas divided by a second axis 1060. Each active display area can emit light reflected by a corresponding optical combiner to a corresponding eye. The surface profile of the surface within each active display area can be, for example, an annular surface formed by rotating a basic curve about the second axis 1060 with a first radius 1080. The second axis 1060 can further coincide with a vertical reference plane formed by the vertical direction and the longitudinal direction, and further form a second angle 1070 with the longitudinal direction. The second angle 1070 (in degrees) can be any angle greater than 0° and less than 90°.

[0075] Figure 11Two curved displays 1100, 1150 are shown according to various embodiments of the present disclosure. The two curved displays 1100, 1150 constitute an augmented reality system (e.g., Figure 1 The image source of the head-mounted augmented reality system 1150. The first of the two curved displays 1100 includes a first axis 1110, a first angle 1120, a second angle 1125, a first radius 1130, and a first basic curve 1140. The second of the two curved displays 1150 includes a second axis 1160, a third angle 1170, a fourth angle 1175, a second radius 1180, and a second basic curve 1190. In some embodiments, the first of the two curved displays 1100 and the second of the two curved displays 1150 may be symmetrical.

[0076] As shown in the figure, two curved displays 1100 and 1150 constitute an image source. Each of the two curved displays 1100 and 1150 has an active display area that emits light reflected to the corresponding eye by a corresponding optical combiner. For example, the surface profile of each surface within each active display area can be a cylindrical surface formed by sliding a first fundamental curve 1140 and a second fundamental curve 1190 along a first axis 1110 and a second axis 1160, respectively. For example, the surface profile of each surface within each active display area can be an annular surface formed by rotating the first fundamental curve 1140 and the second fundamental curve 1190 around the first axis 1110 and the second axis 1160 with a first radius 1130 and a second radius 1180, respectively. The first axis 1110 and the second axis 1160 form a first angle 1120 and a third angle 1170 relative to a horizontal reference plane parallel to the longitudinal and horizontal directions. The first angle 1120 and the third angle 1170 (in degrees) can be any angle greater than 0° and less than 90°. The first axis 1110 and the second axis 1160 may further form a second angle 1125 and a fourth angle 1175 relative to a vertical reference plane parallel to the longitudinal and horizontal directions. The second angle 1125 and the fourth angle 1175 (in degrees) may be any angle greater than or equal to 0° and less than 90°.

[0077] While examples and features of the disclosed principles are described herein, modifications, adjustments, and other implementations may be made without departing from the spirit and scope of the disclosed embodiments. Furthermore, the words “comprising,” “owning,” “including,” and “having,” and other similar forms are intended to be semantically equivalent and open-ended, as one or more items following any of these words do not imply an exhaustive list of such items or a limitation to the listed items. It must also be noted that, as used herein and in the appended claims, the singular forms “a” and “the” include plural references unless the context clearly specifies otherwise.

[0078] The embodiments shown herein have been described in sufficient detail to enable those skilled in the art to practice the disclosed teachings. Other embodiments may be used and derived therefrom, allowing for structural and logical substitutions and changes without departing from the scope of this disclosure. Therefore, the description is not intended to be restrictive, and the scope of the various embodiments is defined only by the appended claims and all their equivalents.

Claims

1. An augmented reality device comprising two optical combiners, an image source, and a housing structure, wherein: The two optical combiners are configured to correspond to the user's two eyes respectively. Each of the two optical combiners includes an inner surface for reflecting light from the image source to the user's corresponding eye and an outer surface for allowing light from the real world to enter the corresponding optical combiner. Both the outer and inner surfaces are free surfaces having a surface function based on an XY polynomial comprising at least one multivariate monomial. The surface functions of the outer and inner surfaces of the two optical combiners are: Where z is the concavity of the surface parallel to the z-axis, x and y are the coordinates in the coordinate system of the corresponding optical combiner, c is the vertex curvature, k is the conic constant, and r equals c j It is the j-th single item x m y n The coefficients, m and n are non-negative integers; Each surface function of the outer surface is optimized by using ray tracing and is based on the design of the corresponding inner surface and the refractive index of the material used for the two optical combiners; Each of the two optical combiners includes a first local curvature on the inner surface corresponding to an outward field of view and a second local curvature corresponding to an inward field of view; the image source is located above the user's eyes and is configured to emit light onto the inner surfaces of the two optical combiners, wherein the image source includes two active display areas located on two different planes; The image source includes two independent display panels, and the two independent display panels are respectively corresponding to the user's eyes; Each of the two active display areas is a part or all of one of the two independent display panels, and each of the independent display panels is associated with one of the two optical combiners. The two independent display panels are not coplanar and are arranged relative to a reference plane formed by a horizontal axis and a vertical axis, each of the two independent display panels having a lower edge that coincides with the reference plane; Each display surface of the two independent display panels forms a first angle with the reference plane at the lower edge of each independent display panel, wherein the first angle is between 45 degrees and 90 degrees; The lower edges of the two independent display panels each form a second angle with the horizontal axis, wherein the second angle from the horizontal axis to the left display panel is counterclockwise, and the second angle from the horizontal axis to the right display panel is clockwise; and The housing structure is configured to maintain the relative position and orientation of the two optical combiners and the image source.

2. The augmented reality device according to claim 1, wherein, Each of the two active display areas is at an angle about the vertical axis, with the absolute value of the angle being between 0 degrees and 45 degrees.

3. The augmented reality device according to claim 1, wherein, Each of the active display areas is at an angle about the vertical axis, the absolute value of which is between 0 degrees and 45 degrees.

4. The augmented reality device according to claim 1, wherein, The image source includes a liquid crystal display, a micro LED display, an organic light-emitting diode display, or an active matrix organic light-emitting diode display.

5. The augmented reality device according to claim 1, wherein: The inner surface is coated with a partially reflective and partially transmissive layer; The outer surface is coated with an anti-reflective layer; and Each of the two optical combiners also includes a semi-transparent substrate located between the inner surface and the outer surface.

6. The augmented reality device according to claim 1, wherein: The surface function has parameters including vertex curvature, quadratic curve constant, and constants associated with the multivariate monomial, wherein all parameters are nonzero.

7. The augmented reality device according to claim 1, wherein, The housing structure also includes a headband configured to maintain the position and orientation of the two optical combiners and the image source relative to the user's head.

8. The augmented reality device according to claim 1, wherein, The housing structure includes an optical clamp configured to allow each of the two optical combiners to: The image is rotated about the horizontal axis to maintain the rotational position, thereby reflecting light to or from the user's respective eyes and hiding the enhanced image.

9. The augmented reality device according to claim 1, wherein, The housing structure includes an optical clamp configured to allow each of the two optical combiners to be detached from the housing structure.

10. The augmented reality device according to claim 1, wherein, The housing structure also includes a thin-film light valve that controls the transparency level of the substrate of each of the two optical combiners.

11. The augmented reality device according to claim 1, further comprising: A computing device, connected to the image source, is configured to generate an image to be presented by the image source on the inner surfaces of the two optical combiners; as well as The power supply is configured to provide power to the image source and the computing device.

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