Nvidia Patent | Prescription Augmented Reality Display
Patent: Prescription Augmented Reality Display
Publication Number: 20200326543
Publication Date: 20201015
Applicants: Nvidia
Abstract
In an embodiment, an augmented reality display is provided that incorporates a prescription lens for the wearer. In an embodiment, an image is generated from a display and directed into the edge of the prescription lens, and the lens acts as a waveguide. The image is internally reflected within the prescription lens, and is directed to the wearer by an image combiner embedded within the prescription lens. In an embodiment, the augmented reality display can be adjusted for many common vision problems including myopia, hyperopia, astigmatism, and presbyopia.
BACKGROUND
[0001] Augmented reality (“AR”) is an emerging field in which graphical elements are added to an image of the real world. Augmented reality displays can be constructed in a number of ways. For example, some handheld devices implement a type of augmented reality by capturing an image of the real world with a camera, adding computer-generated images to the captured image, and then displaying the augmented imaged on the mobile display. Other devices such as Google Glass attempt to add a generated image to eyeglasses similar to a heads-up display. Creating effective AR displays is particularly difficult when the user of the display uses a form of corrective vision. Allowing for use with existing corrective eyewear often results in a bulky and cumbersome display, and using the AR display without corrective eyewear results in a blurry or unclear display. Since a significant portion of the population relies on prescription eyewear to see properly, producing an effective AR display that allows for vision correction is an important problem.
BRIEF DESCRIPTION OF THE DRAWINGS
[0002] Various techniques will be described with reference to the drawings, in which:
[0003] FIG. 1 illustrates an example of a prescription augmented reality display worn by a user, in accordance with an embodiment;
[0004] FIG. 2 illustrates an example of an augmented reality display integrated into prescription eyeglasses, in accordance with an embodiment;
[0005] FIG. 3 illustrates an example of an image produced by an augmented reality display, in accordance with an embodiment;
[0006] FIG. 4 illustrates an example of a lens assembly of an augmented reality display, in accordance with an embodiment;
[0007] FIG. 5 illustrates an example of a display unit and lens geometry that combines the output of the display unit with a prescription lens to form an augmented reality display, in accordance with an embodiment;
[0008] FIG. 6 illustrates an example of a prescription lens assembly with an image combiner, in accordance with an embodiment;
[0009] FIG. 7 illustrates an example of prescription augmented reality for a myopic eye, in accordance with an embodiment;
[0010] FIG. 8 illustrates an example of a spot diagram for a prescription lens with and without CYL power, in accordance with an embodiment;
[0011] FIG. 9 illustrates an example of the angular resolution of a foveated AR display, in accordance with an embodiment;
[0012] FIG. 10 illustrates an example of a process that, as a result of being performed, optimizes a prescription lens of a prescription AR display, in accordance with an embodiment;
[0013] FIG. 11 illustrates an example of a process that, as a result of being performed, optimizes an AR display of a prescription AR display, in accordance with an embodiment;
[0014] FIG. 12 illustrates an example of a design trade-off space for lens thickness and eye box size for a prescription AR display, in accordance with an embodiment;
[0015] FIG. 13 illustrates an example of a correlation between a display panel shift and an image plane shift for a prescription AR display, in accordance with an embodiment;
[0016] FIG. 14 illustrates an example of a design trade-off space for vertical field of view and eye relief for a prescription AR display, in accordance with an embodiment;
[0017] FIG. 15 illustrates an example of an AR display with an adjustable image position, in accordance with an embodiment;
[0018] FIG. 16 illustrates an example of the angular resolution of a foveated display, in accordance with an embodiment;
[0019] FIG. 17 illustrates an example of a parallel processing unit (“PPU”), in accordance with an embodiment;
[0020] FIG. 18 illustrates an example of a general processing cluster (“GPC”), in accordance with one embodiment;
[0021] FIG. 19 illustrates an example of a memory partition unit, in accordance with one embodiment;
[0022] FIG. 20 illustrates an example of a streaming multi-processor, in accordance with one embodiment;* and*
[0023] FIG. 21 illustrates a computer system in which the various examples can be implemented, in accordance with one embodiment.
DETAILED DESCRIPTION
[0024] The present document describes an augmented reality display that integrates a prescription lens for vision correction. In an embodiment, an augmented reality (“AR”) display presents virtual images in real-world scenes while preserving the viewer’s natural vision. In at least one embodiment, an optical structure is provided that has a slim form factor, a high-resolution, large field-of-view (FOV), large eye box, and variable focus. In an embodiment, the diverse spectrum of human head shape and eye structure aggravates this challenge further. Various users have different interpupillary distance (IPD, 54-68 mm) and nose shapes, which raise the bar on eye box and eye relief coverage beyond the requirement for a single user. More than 40% of the population uses special aids for vision correction caused by myopia, hyperopia, astigmatism, and presbyopia. Unlike other designs that may be used with prescription eyeglasses, at least one embodiment described herein provides an AR display that includes corrective lenses adapted to the viewer’s prescription. By integrating the viewer’s prescription into the AR display, overall weight and size of the system can be improved significantly.
[0025] In an embodiment, a prescription-embedded AR display is provided. In an embodiment, an optical design for the AR display utilizes a prescription lens as a waveguide for the AR display. In an embodiment, a free-form image combiner is embedded in the prescription lens, allowing the one-piece lens to both deliver virtual scenes and also correct the vision of a real-world scene simultaneously. In at least one embodiment, the image combiner is a half-silvered mirror or semi-reflective film. In an example of an embodiment, a shape for the prescription lens is provided for a modified myopia eye model. In an embodiment, a free-form image combiner, in-coupling prism, and beam-shaping lens are optimized based on each individual prescription lens. In at least one embodiment, customized ergonomic eye-glasses design is achieved by using a 3D facial scanning. In at least one embodiment, a Prescription AR prototype with a 5-mm thick lens provides 1 diopter (1 D) vision correction, 23 cycles per degree (cpd) angular resolution at center, 4 mm eye box, and varifocal (0 D-2 D) capability. In an least one embodiment, the prototype is lightweight (169 g for dynamic and 79 g for static prototype), has 70% transparency, protects user’s privacy, and enables eye-contact interaction with surroundings.
[0026] FIG. 1 illustrates an example of a prescription augmented reality display worn by a user, in accordance with an embodiment. In at least one embodiment, the wearer 102 equips the augmented reality display in a manner similar to conventional eyeglasses. In at least one embodiment, at least one augmented reality lens 104 is held by a frame 106 which is worn by the wearer 102. In at least one embodiment, two augmented reality lenses are provided in the augmented reality display to provide binocular vision of the augmented images.
[0027] In at least one embodiment, the augmented reality display positions the lenses close to the wearer’s face so that the eye relief and eye box of the display can be minimized. In at least one embodiment, the augmented reality lens 104 provides three regions through which the wearer can look. In at least one embodiment, a first region 108 at the top of the augmented reality lens and a third region 112 at the bottom of the augmented reality lens provide an optical correction in accordance with a corrective vision prescription of the wearer. In at least one embodiment, a second region 110 in the middle of the augmented reality lens includes an image combiner constructed from a half mirrored surface embedded within the lens. In at least one embodiment, an image injected down through the edge of the lens from a display within the frame is reflected internally within the lens until it comes in contact with the image combiner. In at least one embodiment, the image is redirected towards the eye of the wearer along with an image of the real world that is transmitted through the lens and the image combiner. In at least one embodiment, the first region 108 and the third region 112 are coated with a neutral density filter so that the image transmission through the lens is roughly even from the top to the bottom of the lens. In at least one embodiment, the view through the second region 110 includes both transmitted images from the real-world and images generated from the electronic display within the frame of the augmented reality display.
[0028] In at least one embodiment, the profile of the lens 104 is adapted in accordance with a vision prescription of the wearer. In at least one embodiment, the image combiner is formed within the lens and has a surface profile that similarly presents an in-focus image in accordance with the vision correction needed by the wearer. In at least one embodiment, the position of the virtual image originating from within the display on the augmented reality display can be altered by moving the position of the display in relation to the frame either manually or by electronic servo.
[0029] FIG. 2 illustrates an example of an augmented reality display integrated into prescription eyeglasses, in accordance with an embodiment. In at least one embodiment, the augmented reality display is produced in an eyeglass form factor having a frame with two arms 202 and 204. In at least one embodiment, a power and control unit 206 drives a pair of electronic displays mounted in the top of the frame. In at least one embodiment, the power and control unit 206 includes one or more buttons to allow control of the display by the wearer. In at least one embodiment, the power and control unit 206 includes a battery, processor, and graphical interface. In at least one embodiment, the processor and graphical interface may include a CPU or GPU as described in FIGS. 16 through 20. In at least one embodiment, the augmented reality display includes two lenses 208 and 210 that include an image combiner within each lens. In at least one embodiment, the image combiner combines the image transmitted through the lens with the image created by the electronic display. In at least one embodiment, the augmented reality display includes a beam-shaping lens and prism, 212 and 214, in each lens that directs the image produced by the electronic display downward into the lens such that the image is internally reflected and directed to the image combiner of each lens.
[0030] FIG. 3 illustrates an example of an image produced by an augmented reality display, in accordance with an embodiment. In at least one embodiment, a first image 302 illustrates an image transmitted through the lens from the real-world to the wearer. In at least one embodiment, a second image 304 illustrates an augmented image seen by the wearer of the augmented reality display. In the example illustrated in FIG. 3, the second image includes a logo and lettering added by the image combiner and produced by an electronic display on the augmented reality display.
[0031] FIG. 4 illustrates an example of a lens assembly of an augmented reality display, in accordance with an embodiment. In at least one embodiment, the augmented reality display includes a free-form image combiner 402 embedded within a prescription lens 404. In at least one embodiment, the prescription lens 404 is fabricated in accordance with a vision correction prescription. In at least one embodiment, the free-form image combiner 402 is made by coating the interface between two parts of the prescription lens 404 with a half-silver material and joining the parts with optical glue.
[0032] In at least one embodiment, the lens assembly includes an in-coupling prism 406 and a beam-shaping lens 408 that, in combination, direct an image produced by a micro LED 412 into the edge of the prescription lens 404. In at least one embodiment, the beam-shaping lens 408 is retained in position by a lens holder 410 secured to a frame of the augmented reality display. In at least one embodiment, the micro-LED is held in pace with a panel holder 414. In at least one embodiment, the panel holder 414 includes a manual or electronic actuator that allows the micro-LED to be moved along the optical axis of the beam-shaping lens. In at least one embodiment, movement of the micro-LED panel is accomplished with a thumbscrew attached to the threaded rod. In at least one embodiment, movement of the micro LED panel is accomplished using an ultra-thin auto focus actuator module (“UTAF”).
[0033] FIG. 5 illustrates an example of a display unit and lens geometry that combines the output of the display unit with a prescription lens to form an augmented reality display, in accordance with an embodiment. FIG. 5 illustrates a side view and the beam path of an embodiment. In at least one embodiment, a prescription lens 502 works both for vision-correction and as a wave-guide for an AR image produced by a micro display 504. In at least one embodiment, light rays from the micro display 504 are refracted by a beam-shaping lens 506 and enter the prescription lens through an in-coupling prism 508 to create a magnified virtual image located a distance d.sub.i from an eye 510. In at least one embodiment, the virtual image depth can be dynamically changed from 0 D to 2 D by moving the micro display 504 axially (.DELTA.a).
[0034] In at least one embodiment, a prescription AR display optically corrects a user’s vision with a prescription lens, and utilizes the prescription lens as a waveguide in an AR display system. As shown in FIG. 5, the top surface of the prescription lens of thickness t.sub.1 is used as an entrance of the waveguide. In at least one embodiment, the light rays from a micro display of size w.sub.d.times.h.sub.d and resolution N.sub.x.times.N.sub.y located in front of the user’s forehead with an angle .theta..sub.d are refracted by a bi-convex (R.sub.11, R.sub.12) beam-shaping lens (refractive index: n.sub.1, thickness: t.sub.BSL) located at a distance a from the micro display with the tilted angle .theta..sub.1 and entered to the waveguide through an in-coupling prism (refractive index: n.sub.1) located at d.sub.p from the beam-shaping lens with the tilted angle .theta..sub.p. In at least one embodiment, the in-coupling prism is composed by a set of a plano-concave and a convex-plano cylindrical lens. In at least one embodiment, the rays are refracted by a cylindrical lens (R.sub.cy, refractive index: n.sub.2) located at t.sub.c from the prism surface with the tilted angle .theta..sub.c and travel in the waveguide (refractive index: n.sub.3, tilted angle: .theta..sub.w) located at t.sub.w from the cylindrical surface as shown in FIG. 4. In an embodiment, the light rays are internally reflected twice by the frontal surface (S.sub.f) and the rear surface (S.sub.r) of the prescription lens, reflected by a free-form half-mirror coated surface (S.sub.free, tilted angle: .theta..sub.f), and arrive at the pupil of the eye. In at least one embodiment, the in-coupling prism, cylindrical lens, upper part of the prescription lens, and lower part of the prescription lens are bonded by an optical adhesive, such that the prescription lens is comprised of two lens pieces: the main lens and the beam-shaping lens. In at least one embodiment, the enlarged virtual image of size w.sub.i.times.h.sub.i is located at distance d.sub.i from the eye in the vision-corrected real scene. In at least one embodiment, the virtual image depth can be dynamically adjusted (.DELTA.d.sub.i) by moving the micro display back and forth (.DELTA.a).
[0035] In at least one embodiment, the optical design process includes two phases: the prescription lens design (S.sub.f, S.sub.r) and the AR display path design using an optics simulation tool such as Zemax OpticStudio. The overall optical path is difficult to investigate using an analytic form because of the free-form surface and the multiple off-axis components utilized in the display. Nevertheless, in at least one embodiment, a universal design and optimization method is demonstrated which is valid for many prescriptions including myopia, astigmatism, hyperopia, and presbyopia. FIGS. 10-11 show an example of the two-phase optimization process in Prescription AR, which is started from the user’s eyeglasses prescription including spherical correction (SPH), cylinder correction (CYL), axis of astigmatism (AXIS), and add power (ADD).
[0036] FIG. 6 illustrates an example of a prescription lens assembly with an image combiner, in accordance with an embodiment. In at least one embodiment, the prescription lens is constructed using two injection molded pieces. In at least one embodiment, a first lens part 602 and a second lens part 604 are joined with optical glue at an interface. In at least one embodiment, a half-silvered image combiner is placed within the interface and is embedded within the assembled lens.
[0037] FIG. 7 illustrates an example of prescription augmented reality for a myopic eye, in accordance with an embodiment. In at least one embodiment, the first phase is the optimization of the prescription lens, including the frontal (S.sub.f) and rear (S.sub.r) surface profile. FIG. 7 shows, in one embodiment, how to design the prescription lens for a myopic eye. As shown in FIG. 7, the normal vision whose amplitude of accommodation is 4 D has a far point at 0 D and near point at 4 D. The 1 D myopic eye with the same amplitude of accommodation has a far point at 1 D and near point at 5 D. So the observer cannot perceive full-resolution image of the objects located at 0.6 D. In at least one embodiment, the prescription lens shifts the object at infinity to the myopic eye’s far point (1 D) so that the objects are imaged at 1.6 D plane, inside the depth of field (DOF). In at least one embodiment, the prescription lens compensates for astigmatism by adding inverse cylinder power to the given axis.
[0038] In at least one embodiment, instead of using direct calculation of surface profiles from the SPH, CYL, AXIS, and ADD values, both surfaces are determined using a human eye model. In at least one embodiment, this determination method reduces the aberration at the given thickness t.sub.1, refractive index n.sub.3, and given eye relief d.sub.e. Atchison built a human myopic eye model based on the measured data from 121 subjects, and it is known in the art that the total astigmatism is the sum of the corneal and internal astigmatism. However, there isn’t a general human eye model covering the both myopia and astigmatism. The techniques presented in the present document assume corneal astigmatism only and modified the corneal surface property of the Atchison’s model. This assumption is valid in this case because the prescription lens is affected by the sum of the astigmatism, not the source. The cornea surface profile C.sub.rv and C.sub.rh are calculated from the CYL and AXIS value, and the modified eye model is achieved with SPH value as shown in Table 1 below.
[0039] In at least one embodiment, Table 1 below shows the modified myopia eye model based on Atchison’s model where the r.sub.x and r.sub.y are the radius values of a bifocal system in horizontal and vertical respectively, k.sub.x and k.sub.y are the conic constant of bifocal system in horizontal and vertical respectively, N.sub.d is the reflective index of material, and V.sub.d is the Abbe number of the material. In at least one embodiment, the radius of cornea surface, r*.sub.x, is calculated by adding the CYL power into another direction as D.sub.x=D.sub.y+CYL, where the D.sub.y=(N.sub.d-1)/r.sub.y. The compete equation of r.sub.x is expressed below as Eq(1).
TABLE-US-00001 Surface Type Radius Conic Thickness Material Rotation Cornea biconic r*.sub.x = (Nd - 1)/D.sub.x k.sub.x = -0.15 0.55 Nd = 1.376 90-AXIS (.degree.) r.sub.y = 7.77 + 0.022SR k.sub.y = -0.15 Vd = 55.468 Aqueous standard 6.40 -0.275 3.05 Nd = 1.3337 – Vd = 50.522 Stop standard infinite – 0.1 Nd = 1.337 – Vd = 50.522 Anterior gradient 11.48 -5.00 1.44 1.371 + 0.0652778Z – lens lens -0.0226659Z.sup.2 -0.0020399(X.sup.2 + Y.sup.2) Posterior gradient infinite – 2.16 1.418 - 0.0100737Z.sup.2 – lens lens -0.0020399(X.sup.2 + Y.sup.2) Vitrous standard -5.90 -2.00 16.28 - 0.299SR Nd = 1.336 – Vd = 51.293 Retina biconic r.sub.x = -12.91 - 0.094SR k.sub.x = 0.7 + 0.026SR – – – r.sub.y = -12.72 + 0.004SR k.sub.y = 0.225 + 0.017SR
[0040] In at least one embodiment, based at least in part on this modified myopia eye model, S.sub.f and S.sub.r are determined. In at least one embodiment, S.sub.f is set as a spherical surface of radius r.sub.f while S.sub.r is set as a bifocal surface of radii r.sub.ro, r.sub.re and rotation angle .theta..sub.r, to correct the myopia and the astigmatism. In an embodiment, the values were optimized iteratively with the merit function for the range of 12 to 20 mm eye relief and 26.times.18 degrees of the field.
[0041] In at least one embodiment, FIG. 8 shows a spot diagram change around the retina plane of a myopic astigmatism eye (SPH: -2, CYL: -2, and AXIS: 30) without and with the prescription lens. In at least one embodiment, compared to the naked eye and the myopia-only correction lens, the designed prescription lens forms a smaller focal point at the retinal plane as shown in FIG. 8. In at least one embodiment, FIG. 8 illustrates a spot diagram on the retina through focus shifting: (a) the blurred spot on the retina from the infinite object without prescription lens, (b) the focused spot on the retina only optimized for SPH, and (c) optimized for SPH, CYL, and AXIS.
r x * = r y .times. ( N d - 1 ) ( N d - 1 ) + CYL .times. r y ( 1 ) ##EQU00001##
[0042] In at least one embodiment, based at least in part on the prescription lens design, other geometric parameters (R.sub.11, R.sub.12, R.sub.cy, a, d.sub.p, t.sub.BSL, t.sub.c, t.sub.w, .theta..sub.d, .theta..sub.1, .theta..sub.p, .theta..sub.c, .theta..sub.w, .theta..sub.free, and S.sub.free) are optimized in the second phase. In at least one embodiment, although actual numbers will be calculated by a tool such as Zemax OpticStudio, the geometry of optics, the materials, the constraints, and the priority (merit function) should be carefully considered at the design stage for the best performance.
[0043] In at least one embodiment, FIG. 5 shows a detailed diagram of the AR display path. In at least one embodiment, in the waveguide, the light rays are reflected at the positive power surface (S.sub.f) first, and at the negative power surface (S.sub.r) second. In at least one embodiment, it is reasonable to choose a positive power image combiner (S.sub.free) for the freeform surface to produce a flatter focal plane, symmetric power distribution, and less aberration. In at least one embodiment, the freeform surface is characterized by an extended polynomial equation including conic aspherical surfaces and extended polynomial terms as follows:
z = c r 2 1 + 1 - ( ( 1 + k ) c 2 r 2 ) + i N A i E i ( x , y ) , ( 2 ) ##EQU00002##
where c is the curvature for the base sphere, r is the normal radius expressed as r= {square root over (x.sup.2)}+y.sup.2, k is the conic constant, N is the number of polynomial terms, and A.sub.i is the coefficient of the i.sup.th extended polynomial terms as Eq(3). In at least one embodiment, as part of the optimization in freeform surface, the 4.sup.th polynomial has been considered, in which N=16 in the Eq(3) below.
.SIGMA..sub.i=0.sup.NA.sub.iE.sub.i(x,y)=A.sub.0+A.sub.1x.sup.1y.sup.0A.- sub.1x.sup.0y.sup.1+A.sub.3x.sup.2y.sup.0+A.sub.4x.sup.1y.sup.1+A.sub.5x.s- up.0y.sup.2+ (3)
[0044] In at least one embodiment, the bi-convex beam-shaping lens increases the system’s numerical aperture (NA) for higher resolution and compactness (shorter optical path). In at least one embodiment, the in-coupling prism guides the light rays into the waveguide with the total internal reflection condition. In at least one embodiment, the y-axis only cylindrical surface (R.sub.cy) inside the in-coupling prism compensates the astigmatism and the tilted image plane, which are caused by the off-axis folded path. In at least one embodiment, the tilted angle of the beam-shaping lens is identical to the tilted angle of the micro-display for the symmetric magnification (.theta..sub.d=.theta..sub.l), but the angles of other components were freely decided by the optimizer to maximize FOV and minimize aberration. In at least one embodiment, the materials for the beam shaping lens and the upper part of the in-coupling prism (n.sub.1, v.sub.1), the lower part of that (n.sub.2, v.sub.2), and the prescription lens (n.sub.3, v.sub.3), where n and v refer to index of refraction and Abbe number respectively, were carefully chosen to minimize the thicknesses and the chromatic aberration using the different dispersion characteristics. In at least one embodiment, the distances (a, d.sub.p, t.sub.BSL, t.sub.c, t.sub.w) were calculated to some non-negative values based on various constraints and the priorities.
[0045] In at least one embodiment, the optical configuration for AR function is limited by giving the constraints for the optical system in the Merit function. In at least one embodiment, the constraints are determined by the comprehensive consideration of lens implementation, distance from forehead, total internal reflection (TIR) inside prescription lens, and boundary on display panel. In at least one embodiment, the center thickness and edge thickness of each lens, t.sub.BSL, t.sub.c, t.sub.w, are limited to more than one mm for the manufacturability of the lens. In at least one embodiment, constraints for the air thickness, a, dp, are limited to more than 0.2 mm to avoid the superposition of the lens. In at least one embodiment, the sum of thickness a, d.sub.p, t.sub.BSL, t.sub.c, and t.sub.w are limited to within 8.5 mm to minimize total thickness of AR system.
[0046] FIGS. 10-11 illustrate an embodiment of the two-phase optimization of a prescription AR display. In at least one embodiment, the frontal and rear surfaces (S.sub.f, S.sub.r) are optimized at given lens thickness t.sub.1 in the first step based on user’s prescription. In at least one embodiment, other geometric parameters (R.sub.11, R.sub.12, R.sub.cy, a, d.sub.p, t.sub.BSL, t.sub.c, t.sub.w, .theta..sub.d, .theta..sub.l, .theta..sub.p, .theta..sub.c, .theta..sub.w, and .theta..sub.free) are optimized in the second step based on target foveated resolution and eye relief range d.sub.e.
[0047] FIG. 10 illustrates an example of a process 1000 that, as a result of being performed, optimizes a prescription lens of a prescription AR display, in accordance with an embodiment. In at least one embodiment, at block 1002, a prescription is obtained for a wearer. The prescription may be, in various embodiments, a prescription for myopia, astigmatism, presbyopia, or various combinations of vision problems. In at least one embodiment, at block 1004, a mathematical model for the eye is generated in accordance with the obtained prescription. In the present document, an example for a myopic eye is presented. In at least one embodiment, at block 1006, a script for Zemax Studio macro as described below is executed with appropriate vision correction parameters. In at least one embodiment, at block 1008, the bifocal power and rotation angle of the z-axis in the cornea surface are determined. In at least one embodiment, at block 1010, the prescription lens surface is initialized, and at block 1012, the Merit function criterion is set. In at least one embodiment, at block 1014, the bifocal radius and rotated angle of the prescription lens surfaces optimized, and at block 1016, optimization of the prescription portion of the AR display is complete.
[0048] FIG. 11 illustrates an example of a process 1100 that, as a result of being performed, optimizes an AR display of a prescription AR display, in accordance with an embodiment. In at least one embodiment, at block 1102, the prescription lens parameters determined above are obtained. In at least one embodiment, at block 1104, the relationship between the image combiner and the display panel is modeled. In at least one embodiment, the relationship establishes a foveated image that is presented to the wearer. In at least one embodiment, at block 1106, the parameters defining the AR display, including the image combiner, are determined. In at least one embodiment, at block 1108, the constant of the merit function is established. In at least one embodiment, at block 1110, the resolution distribution of the foveated display is set. In at least one embodiment, the resolution of the foveated display is achieved as a result of the electronic micro-display being flat, and the optics of the beam shaping lens and optical path correcting the shape of the display to match the image combiner. In at least one embodiment, the resolution density presented to the wearer’s illustrated in FIG. 9. In at least one embodiment, at block 1112, the polynomial coefficient surface performance of the surfaces optimized. In at least one embodiment, at block 1114, due to the adjustment of the foveated display, a center resolution of over 23 cycles per degree (“CPR”) is achieved. In at least one embodiment, at block 1116, the AR display optimization is complete.
[0049] In at least one embodiment, where the thickness of the prescription lens is 5 mm, the size of the free-form combiner is limited, especially in the vertical field of view. In at least one embodiment, the thicker prescription lens allows a larger field of view by the larger size of the combiner. In at least one embodiment, although it is complicated to evaluate the FoV from the free-form surface and reflection constraint of the light path, tools such as Zemax Studio provide an effective way to get the vertical field of view. As shown in FIGS. 12-14, the trend line is linear to the thickness of the prescription lens. In at least one embodiment, the eye box size grows with lens thickness.
[0050] FIGS. 12-14 illustrate an embodiment of a design trade-off space for the prescription AR display. In at least one embodiment, the micro display w.sub.d.times.h.sub.d=10.08.times.7.56 mm and pixel pitch 6.3 .mu.m, virtual image plane d.sub.i=1 D, and thickness t.sub.1=5 mm. FIG. 12 illustrates thickness vs. FOV and eye box. In at least one embodiment, both FOV and eye box are proportional to the t.sub.1. FIG. 13 illustrates focus cue. In at least one embodiment, the virtual image plane can be changed back and forth (.DELTA.d.sub.i) with the axial movement of the micro display (.DELTA.a). FIG. 14 illustrates Eye Relief vs. FOV. In at least one embodiment,* smaller eye relief provides larger FOV*
[0051] FIG. 9 illustrates an example of the angular resolution of a foveated AR display as viewed by the wearer, in accordance with an embodiment. In at least one embodiment, the AR display is a fixed foveated display. In at least one embodiment, the AR display is adjusted to the foveated resolution distribution, which presents a high angular resolution, 26 CPR, at the foveal region and a low angular resolution, 3 cpd, outside of foveated region in optics. In at least one embodiment, the panel used is a 6.3 .mu.m micro-OLED, which can reach to 23 CPR of angular resolution. In at least one embodiment, an optimization is performed done in Zemax Studio by giving the foveated weight of optimized priority order for the field. In at least one embodiment, the special frequency date of MTF30 is extracted from Zemax Studio and the data is converted into angular resolution by calculating the field of view of the AR image, as shown in FIG. 9. In at least one embodiment, the high-resolution region is not symmetric because it is hard to perfectly compensate the AXIS angle of astigmatism. FIG. 9 illustrates foveated optimization of angular resolution over FOV for a 1 D myopia prescription AR display.
[0052] In at least one embodiment, using the techniques described herein, a person of ordinary skill in the art is able to adjust the prescription AR display to correct for most vision problems including myopia, astigmatism, presbyopia, and various combinations these problems. In various embodiments, the prescription AR is adaptable to multiple myopia cases (0 D (normal vision), 1 D, 2 D, 3 D, 4 D, and 5 D) and a myopic astigmatism case (SPH=2 D, CYL=2, AXIS=30). Table 2 shows design parameters for one embodiment of a 1 D myopia Prescription AR display. Table 2 shows the geometric and optical parameters of one embodiment of prescription AR for 1 D myopia.
TABLE-US-00002 TABLE 2 The designed performance of implemented prescription embedded AR display. Items Units Values Prescription diopther -1 Lens thickness mm 5 Eye relief mm 20 Eye box mm 4 Image object m, through the lens 1 Field of view degrees 20 .times. 40 Resolution cycles per degree(CPR) 23** at center**
[0053] In at least one embodiment, the fabrication of the optical components may be accomplished with the following techniques. In at least one embodiment, since facial structure is unique to the wearer, the ergonomic frame design is as important as the optics design. In at least one embodiment, the optics for the eye relief of the AR display is optimized in the range of 12 mm to 20 mm. In at least one embodiment, however, smaller eye relief can provide a larger FOV and a more comfortable fit (closer center of mass). In at least one embodiment, the center of the pupil should be aligned with the optical axis for a superior foveated experience. In at least one embodiment, frame design of the glasses should be chosen in accordance with the wearer’s interpupillary distance (“IPD”) too.
[0054] In at least one embodiment, the facial structure of the intended wearer as illustrated in FIG. 1 is 3D-scanned with a 3D-Camera such as the Kinect sensor from Microsoft, and imported to 3D-rendering software (such as Fusion 360), and the glasses frame is designed and optimized for each user. In at least one embodiment, the glasses frame designs are parameterized with the input of the IPD and the width of the head, followed by fitting if the nose pieces.
[0055] In at least one embodiment, an OLED-based dynamic prototype was created with the following features. In at least one embodiment, two 10.08.times.7.56 mm Sony micro OLED (ECX339A) displays were used as binocular micro displays, where each display has 1600.times.1200 resolution, 6.3 .mu.m pixel pitch, and maximum brightness 1000 cd/m2. In at least one embodiment, the free-form optics with the 70% transparency for 1 D myopia were fabricated. In at least one embodiment, a 3D-printed frame housed and aligned the optical structures including main lens+in-coupling prism, beam-shaping lens, micro display, and driving board. In at least one embodiment, a 3D printed gear was also applied to change the IPD. In at least one embodiment, the weight of the dynamic prototype including the driving board was 164 g.
[0056] In at least one embodiment, an LVT-based static prototype was created with the following features. In at least one embodiment, two sets of a 10.08.times.7.56 mm, 3048 pixel per inch light valve technology (LVT) film with an ElectroLuminesent (EL) film back light were used for the static display. In at least one embodiment, a CR-2032 coin cell powered both EL films. In at least one embodiment, a 3D-printed housing aligned all of the optics, statics display modules, and the battery for wearable eye glasses form factor. In at least one embodiment, the weight of the static prototype was 79 g.
[0057] In at least one embodiment, the image content for the prototype is a binocular image. In at least one embodiment, the binocular image is produced by a G3D Innovation Engine which is a powerful rendering engine with the open source of C++ program. In at least one embodiment, the rendering engine supports the image rendering of virtual reality that allows the customer to add the scene by a virtual reality platform such as VRapp. In at least one embodiment, in the coding of the virtual reality platform, the field of view, depth of focus, pupillary distance, and resolution are set with same parameter of the prescription-embedded AR display. In at least one embodiment, the field of view measurement of the AR image covered 20 by 40 degrees in the vertical and horizontal direction respectively.
[0058] In at least one embodiment, the AR display achieves corrected vision. In an experiment conduced on a prototype of an embodiment, a scene for different real objects including a car, a horse, and an eye chart with a distance of 0.5 m, 1 m, and 3 m respectively, was used. In at least one embodiment, in order to imitate a wearer who has a 1 diopter myopia eye, the camera focused on the car in the scene without the prescription-embedded AR display. The clear details on the car show that a 1 diopter myopia eye is able to clearly view an object at 0.5 m. In at least one embodiment, using the prescription-embedded AR display, the focus point shifted to 1 m to target the horse, without changing the setting of focus on the camera. The focus shift amount demonstrates that the prescription lens has -1 diopter power. In at least one embodiment, a clear AR image is presented by the display panel at 1 m distance through the prescription embedded AR display, and the eye chart looks sharper due to the contribution of vision correction.
[0059] FIG. 15 illustrates an example of an AR display with an adjustable image position, in accordance with an embodiment. In at least one embodiment, the AR display can be adapted to operate as a vari-focal AR display. As shown in FIG. 15, a three-position Micro-OLED (“MOLED”) panel 1502 with size, Pd, and shifting distance, .delta.d, makes the different depth of AR image at d1, d2, and d3 from the eye, where equal to 0.5 m, 1 m, and 3 m, respectively. In at least one embodiment, three kinds of thickness of assemblies for Micro-OLED panel provide the shifting amount of 0.3 mm, .delta.d. In at least one embodiment, the depth of the clear AR image is controlled and produces a vari-focal display that reduces the problem of vergence and accommodation conflict (VAC) in the near-eye display system.
[0060] In at least one embodiment, a vision correction function is an important property in a near-eye display system. In at least one embodiment, an AR display is directly integrated into a prescription lens. In at least one embodiment, each individual AR display is adapted to include a customized prescription lens in accordance with a prescription of SPH, CYL, and AXIS. In at least one embodiment, the configuration of the optical components can be used for the myopia patient with 0 to -7 diopter, -2 diopter of astigmatism, and rotation angle of astigmatism.
[0061] In at least one embodiment, a free-form image combiner is made by molding a prescription lens in two pieces and coating the interface between the two pieces with anti-reflective coating and 30% of ND filter coating. In at least one embodiment, the system achieves a field of view of 20 by 40 degrees and a foveated resolution distribution of 23 CPR in the foveal region. In at least one embodiment, the eye box size is 4 mm. In at least one embodiment, the prescription-embedded AR display described herein offers both corrected vision and a clear AR image at 1 m. In at least one embodiment, the depth of the AR image is adjustable from 0.5 m to 3 m by applying a corresponding 0.3 mm shift to the position of the display panel.
[0062] In at least one embodiment, the prescription embedded AR display is a compact design, which provides a volume of 6.5 cm3 for the optical engine, including the 5 mm thickness prescription lens, other optical elements, and a micro-OLED. In at least one embodiment, the prescription embedded AR display achieves vision correction for the environment scene and also gives a clear AR image for the wearer.
[0063] FIGS. 16-20 illustrate various systems that can be used to implement various embodiments of the invention. The systems illustrated and discussed in connection with FIGS. 16-20 may be used, for example, to execute instructions to perform algorithms discussed herein including but not limited to image processing (e.g., object detection, object recognition, image segmentation, and other techniques) and calculating display information (e.g., the display to be rendered and/or a portion thereof, such as content to be added to an image captured through one or more cameras). Software to implement the various techniques described herein can be executed using one or more of the systems discussed below and illustrated in connection with FIGS. 16-20.
[0064] In at least one embodiment, the AR display includes an electronic display such as an organic light emitting diode (“OLED”), light emitting diode (“LED”), light valve technology (“LVT”) display, or liquid crystal display (“LCD”). In at least one embodiment, the electronic display produces an image which is directed through a beam-shaping lens and in-coupling prism into the edge of the lens of the AR display. In at least one embodiment, the image is internally reflected within the lens by the surfaces of the lens until the image encounters a free-form image combiner located internally to the lens. In at least one embodiment, the surface profile of the image combiner is constructed as described herein so that both the image transmitted through the lens, and the image generated by the AR display are presented to a wearer in accordance with a vision prescription for corrective eyewear.
[0065] In at least one embodiment, a computer system with one or more processors is coupled to the electronic display, and the computer system includes memory and instructions that, when executed, cause the computer system to generate electrical signals that are transmitted to the electronic display. In at least one embodiment, the electrical signals are converted by the electrical display into an image. In at least one embodiment, an augmented reality graphics framework such as Spark AR, Wikitude, ARKit or ARCore on the computer system allows an application developer to create software, that when run on the computer system, directs the addition of augmented reality elements on the AR display.
[0066] FIG. 17 illustrates a parallel processing unit (“PPU”) 1700, in accordance with one embodiment. In an embodiment, the PPU 1700 is configured with machine-readable code that, if executed by the PPU, causes the PPU to perform some or all of the processes and techniques described throughout this disclosure. In an embodiment, the PPU 1700 is a multi-threaded processor that is implemented on one or more integrated circuit devices and that utilizes multithreading as a latency-hiding technique designed to process computer-readable instructions (also referred to as machine-readable instructions or simply instructions) on multiple threads in parallel. In an embodiment, a thread refers to a thread of execution and is an instantiation of a set of instructions configured to be executed by the PPU 1700. In an embodiment, the PPU 1700 is a graphics processing unit (“GPU”) configured to implement a graphics rendering pipeline for processing three-dimensional (“3D”) graphics data in order to generate two-dimensional (“2 D”) image data for display on a display device such as a liquid crystal display (LCD) device. In an embodiment, the PPU 1700 is utilized to perform computations such as linear algebra operations and machine-learning operations. FIG. 17 illustrates an example parallel processor for illustrative purposes only and should be construed as a non-limiting example of processor architectures contemplated within the scope of this disclosure and that any suitable processor may be employed to supplement and/or substitute for the same.
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