Systems and methods for variable astigmatism correction in head mounted displays

Abstract

Systems and methods for variable astigmatism correction in a head mounted display are disclosed. An apparatus may include viewing optics. The viewing optics may include a first rotatable phase plate, a second rotatable phase plate, and an adjustable focus device. The viewing optics may be configured to image light from the display, the imaged light having a spherical power, a cylindrical power, and a cylindrical axis. The spherical focal power, the cylindrical focal power and the cylindrical axis of the imaging light can be controlled by adjusting the adjustable focal length device, rotating the first rotatable phase plate and rotating the second rotatable phase plate. Other apparatus, devices, systems, and methods of manufacture are also disclosed.

Description

Cross-references to related applications

[0001] This application claims the benefit of U.S. Provisional Application No. 63 / 701,069, filed September 30, 2024, and U.S. Non-Provisional Application No. 19 / 315,252, filed August 29, 2025, the disclosures of which are incorporated herein by reference in their entirety. Technical Field

[0002] This application relates to systems and methods for variable astigmatism correction in head-mounted displays. Background Technology

[0003] Users requiring vision correction when using augmented reality / virtual reality (AR / VR) headsets can provide their own prescription lenses. For users who wear glasses while using the headset, there are significant issues with comfort and compatibility. Summary of the Invention

[0004] In some examples, a device may include an optical assembly comprising a first phase plate and a second phase plate, the first and second phase plates being disposed on a rotary table that allows mechanical rotation about an optical axis. Focus adjustment may be achieved using any one or more of the following: mechanical translation along the optical axis of a display, lens, or mirror; deformation of an optical element for changing optical power, such as a liquid lens or a deformed refractive or reflective surface; electro-actuated adjustment of a liquid crystal optical element for active focus adjustment; and / or any other suitable focusing mechanism. Attached Figure Description

[0005] The accompanying drawings illustrate several exemplary embodiments and are part of the specification. These drawings, together with the following description, illustrate and explain various principles of this disclosure.

[0006] Figure 1 This is a flowchart of an exemplary method for variable astigmatism correction in a head-mounted display.

[0007] Figure 2 This is a block diagram of an example device for variable astigmatism correction in a head-mounted display.

[0008] Figure 3A This is a graphical illustration of an example optical operation performed by a device used for variable astigmatism correction in a head-mounted display.

[0009] Figure 3B This is a graphical illustration of an example optical operation performed by a device used for variable astigmatism correction in a head-mounted display.

[0010] Figure 4This is a graphical illustration of an example phase diagram of a phase plate used in a device for variable astigmatism correction in a head-mounted display.

[0011] Figure 5 This is a graphic illustration of a pancake lens used in a device for variable astigmatism correction in a head-mounted display.

[0012] Figure 6 It is a graphical illustration of an augmented reality system.

[0013] Figure 7 It is a graphical description of a virtual reality system.

[0014] Throughout the accompanying drawings, the same reference numerals and descriptions indicate similar but not necessarily identical elements. While the exemplary embodiments described herein are readily adaptable and have alternative forms, specific embodiments have been shown by way of example in the drawings and will be described in detail herein. However, the exemplary embodiments described herein are not intended to be limited to the specific forms disclosed. Rather, this disclosure covers all modifications, equivalents, and alternatives falling within the scope of the appended claims. Detailed Implementation

[0015] When using augmented reality / virtual reality (AR / VR) headsets, users requiring vision correction can provide their own prescription lenses. For users who wear glasses while wearing the headset, comfort and compatibility are significant issues. The device can accept "prescription inserts," which can be custom-made prescription lenses attached to the headset. However, each user may require a different prescription, causing considerable inconvenience, especially when different users share a single headset. For example, each user might be required to obtain a custom insert, which may not be convenient to change between device uses.

[0016] VR headsets can adjust for spherical prescription vision correction. For example, the position of a spherical corrective lens can be adjustable by mechanically moving optics or a display along an axis. However, this method cannot correct astigmatism, which may limit the number of users compatible with a particular headset. Ideally, AR / VR headsets would allow for vision correction within both spherical and cylindrical (astigmatism) prescription ranges.

[0017] Example AR / VR devices may include optical components comprising two astigmatic phase plates, such as cylindrical power and cylindrical axis. The optical corrections of the individual phase plates can be additive, so the clocking (e.g., relative rotation) between the phase plates can be used to adjust the total cylindrical power of the optical component. The common clocking of the phase plates relative to the eye (e.g., rotation about an axis passing through the optical center of the phase plates) can be used to adjust the orientation of the axis of cylindrical power. In some examples, the optical component may include at least one additional optical element, such as a separate spherical correction lens, which can be adjusted to compensate for any residual spherical power introduced by the two phase plates and / or control spherical prescription correction.

[0018] In some examples, a VR device may include an optical assembly, as described herein, between a display and an eyebox. As used herein, the eyebox can refer to, for example, the location of virtual reality or augmented reality elements generated by the display that a user can see when wearing the device. In some examples, the augmented reality device may also include an optical combiner configured to combine augmented reality elements with a real-world view. In an augmented reality device, the optical assembly may be located between the optical combiner and the eyebox.

[0019] In some examples, a device may include an optical assembly comprising a first phase plate and a second phase plate, the first and second phase plates being disposed on a rotary table that allows mechanical rotation about an optical axis. Focus adjustment may be achieved using any one or more of the following: mechanical translation along the optical axis of a display, lens, or mirror; deformation of an optical element for changing optical power, such as a liquid lens or a deformed refractive or reflective surface; electro-actuated adjustment of a liquid crystal optical element for active focus adjustment; and / or any other suitable focusing mechanism.

[0020] Figure 1 This is a flowchart of an exemplary method 100 for variable astigmatism correction in a head-mounted display. Figure 1 One or more of the steps shown can be performed by people and / or machines (e.g., workstations, equipment for polishing, grinding, coating, and testing optics, systems for aligning and integrating components into finished assemblies, etc.) in various environments. Alternatively or additionally, Figure 1 One or more of the steps shown can be performed by any suitable computer-executable code and / or computing system, including... Figure 6 and Figure 7 One or more systems are shown. In one example, Figure 1One or more of the steps shown can represent an algorithm whose structure includes and / or is represented by multiple sub-steps, examples of which will be provided in more detail below. In another example, Figure 1 One or more of the steps shown can be performed by user-actuated components, such as a rotatable ring configured to mechanically translate, rotate, or deform optical components.

[0021] like Figure 1 As shown, at step 110, one or more systems in the various systems described herein may configure the viewing optics. For example, at step 110, method 100 may include configuring the viewing optics to image light from a display, wherein the viewing optics includes a first rotatable phase plate, a second rotatable phase plate, and an adjustable focal length device, and the imaging light has spherical power, cylindrical power, and cylindrical axis.

[0022] As used herein, the term "viewing optics" can broadly refer to optical instruments or systems used for viewing or observing things. For example, but not limited to, viewing optics can refer to optical components configured for use in VR, AR, mixed reality (MR), and / or surreal (XR) head-mounted devices. In this context, the optical components can image light from a display and deliver the imaged light to the eyes of the user of the head-mounted device.

[0023] As used herein, the term "display" can broadly refer to one or more active display screens. For example, but not limited to, a display screen can refer to one or more microdisplays designed for viewing by magnification. In this context, such a display screen can be used in head-mounted displays (HMDs), such as VR headsets, AR headsets, MR headsets, and / or XR headsets.

[0024] As used herein, the term "phase plate" can broadly refer to an optical element that manipulates the phase of light. For example, but not limited to, a phase plate can refer to an optical window designed to impart a known and predetermined phase to the wavefront (beam) at output. In this context, the optical window (e.g., an astigmatic phase plate, a Pancharatnam-Berry phase lens surface, a standard refractive optical lens surface or element, etc.) can have varying thickness or material properties that cause light to experience different delays at different points in the beam to provide aberration correction and / or color correction. Also in this context, a rotatable phase plate can have one or more mechanical features (such as gear teeth located at the edge of the rotatable phase plate) that facilitate rotation of the rotatable phase plate under the control of a physical processor.

[0025] As used herein, the term "adjustable focus device" can broadly refer to an optical component or system designed to manipulate light rays to converge at or diverge from a specific point. For example, but not limited to, an adjustable focus device can refer to active liquid crystal optics, lenses, mirrors, liquid lenses, deformable refractive or reflective surfaces, electro-actuated liquid crystal optics for active focus adjustment, etc. In this context, an adjustable focus device may have one or more mechanical features (e.g., rack and pinion systems, etc.) that facilitate linear translation along an optical axis under the control of a physical processor.

[0026] As used herein, the term "spherical power" can broadly refer to the optical power of a lens required to correct myopia (nearsightedness) or hyperopia (farsightedness). For example, but not limited to, spherical power can refer to the amount of correction required to properly focus light onto the retina. In this context, spherical power can be measured in diopters; a negative value can indicate myopia, while a positive value can indicate hyperopia.

[0027] As used herein, the term “cylindrical power” can broadly refer to the amount of lens power required to correct astigmatism. For example, but not limited to, cylindrical power can refer to the degree of irregularity in the curvature of the cornea or lens, which causes light to focus on multiple points on the retina instead of a single point, resulting in blurred or distorted vision.

[0028] As used herein, the term "cylindrical axis" can generally refer to the orientation, measured in diopters, of a cylindrical lens component used for astigmatism correction. For example, but not limited to, the cylindrical axis can refer to the direction in which the lens has no cylindrical power, essentially defining the angle at which the lens should be corrected for astigmatism.

[0029] Method 100 may configure the viewing optics in various ways at step 110. For example, configuring the viewing optics at step 110 may include configuring a viewing optics having an adjustable focus device, the adjustable focus device including an active liquid crystal optics. In another example, configuring the viewing optics at step 110 may include configuring a viewing optics having a first rotatable phase plate, the first rotatable phase plate including an astigmatic phase plate. In another example, configuring the viewing optics at step 110 may include configuring a viewing optics having a first rotatable phase plate, the first rotatable phase plate including a Pancharatnam-Berry phase lens surface. In yet another example, configuring the viewing optics at step 110 may include configuring a viewing optics having a first rotatable phase plate, the first rotatable phase plate including a standard refractive optical lens surface or element. In another example, configuring the viewing optics at step 110 may include configuring the viewing optics having a first rotatable phase plate that provides aberration correction and / or color correction.

[0030] like Figure 1 As shown, at step 120, one or more systems in the various systems described herein can control the spherical power, cylindrical power, and cylindrical axis of the imaging light. For example, method 100 may include at step 120 controlling the spherical power, cylindrical power, and cylindrical axis of the imaging light by adjusting the adjustable focal length device, rotating the first rotatable phase plate, and rotating the second rotatable phase plate.

[0031] Method 100 may control the spherical power, cylindrical power, and cylindrical axis of the imaging light in various ways at step 120. For example, controlling the spherical power, cylindrical power, and cylindrical axis of the imaging light at step 120 may include adjusting the position of the lens relative to the display along the optical axis of the viewing optics including the lens. Alternatively or additionally, controlling the spherical power, cylindrical power, and cylindrical axis of the imaging light at step 120 may include looking up linear translation and / or rotation values ​​by a physical processor based on an input parameter reference lookup table. In this context, the input parameters may include a prescription for correcting vision. Furthermore, the retrieved values ​​may include one or more amounts for mechanically translating the display, lens, and / or mirror along the optical axis. Alternatively or additionally, the retrieved values ​​may include one or more amounts for deforming optical elements (e.g., liquid lenses, deformable refractive or reflective surfaces, etc.) to change the power. Alternatively or additionally, the retrieved values ​​may include one or more amounts for electro-actuating liquid crystal optics for active focus adjustment. Furthermore, the retrieved values ​​may include one or more quantities for mechanically rotating the first and second rotatable phase plates. Finally, controlling the spherical power, cylindrical power, and cylindrical axis of the imaging light at step 120 may include: applying the retrieved values ​​by the physical processor to adjust the adjustable focus device, rotating the first and second rotatable phase plates.

[0032] Figure 2 It shows that it may include according to Figure 1 Method 100 describes an example device 200 configured for viewing optics. For example, device 200 may include a display 202 and an optical assembly 204 (e.g., a viewing optics device) that receives light 206 from the display 202 and directs the light 206 to at least one eye of a user. Optical assembly 204 includes a spherical power adjuster 208 (e.g., a translational and / or deformable lens) and a cylindrical power adjuster that includes a first phase plate 210 and a second phase plate 212.

[0033] In some examples, the first phase plate 210 and / or the second phase plate 212 may be rotatable (e.g., coupled to a rotatable platform). Therefore, as will be explained in more detail below, the optical assembly 204 can allow adjustment of cylindrical power and cylindrical axis (for astigmatism correction) as well as spherical power. Each phase plate 210 and 212 may have cylindrical power. Rotation of phase plates 210 and 212 relative to each other can allow the introduction of adjustable cylindrical power, and may also introduce spherical power. Overall rotation of the pair of phase plates can allow adjustment of the cylindrical axis. An adjustable spherical lens (e.g., spherical power adjuster 208) can allow further adjustment of the spherical power.

[0034] Phase plates 210 and 212 may include any suitable optical elements. Examples of phase plates 210 and 212 may include cylindrical refractive or reflective lenses or any lens having cylindrical power and optional other optical parameters, such as freeform lenses with a cylindrical power component, Pancharatnam-Berry phase lenses (PBP lenses), electrically adjustable liquid crystal lenses, etc. In some examples, the phase plates may have both cylindrical and spherical power (e.g., ellipsoidal power lenses). In some examples, one or more elements of optical assembly 204 may be configured as (e.g., providing a folded optical path via one or more partial reflectors and / or selective reflectors) pancake lenses.

[0035] In some examples, optical component 204 can allow focus adjustment via any of a variety of techniques. For example, optical component 204 can provide mechanical translation of display 202, one or more lenses (e.g., spherical power adjuster 208), and / or reflectors along optical axis 214. In some examples, focus adjustment can be achieved by changing the power by deforming optical elements (e.g., liquid lenses and / or deformed refractive and / or reflective surfaces). In some examples, focus adjustment can be achieved via electro-actuated liquid crystal optics.

[0036] Figure 3A and Figure 3B This demonstrates how various rotational states can be combined. Figure 2 Various optical operations are performed by rotating phase plate 210 (hereinafter referred to as "plate 1") and phase plate 212 (hereinafter referred to as "plate 2"). For example, line 302 shows plate 1 rotated by 0 degrees (producing, for example, 1 diopter along the x-axis) and plate 2 rotated by 0 degrees (producing, for example, 1 diopter along the x-axis). The combined optical effect of plates 1 and 2 can be 2 diopters along the x-axis.

[0037] In another example, line 304 shows plate 1 rotated 0 degrees (producing, for example, 1 diopter along the x-axis) and plate 2 rotated 90 degrees (producing, for example, 1 diopter along the y-axis). The combined optical effect of plates 1 and 2 can be a spherical power of 1 diopter.

[0038] In another example, line 306 shows plate 1 rotated by 0 degrees (producing, for example, 1 diopter along the x-axis) and plate 2 rotated by 45 degrees (producing, for example, 1 diopter at 45 degrees). As shown in line 308, this can produce an intermediate result 314 of 1.25 diopter at 22 degrees when the resulting combined optical effect 310 is further modified by removing the remaining optical power at 312 (e.g., 0.4 diopter using a spherical focusing mechanism). Then, at 316, both plates 1 and 2 can be rotated together to control the axis of cylindrical optical power generation. In this way, rotation of the two phase plates, consistent with the adjustment of the spherical focusing mechanism, can produce cylindrical adjustment with the desired optical power and orientation.

[0039] Figure 4 Example phase diagrams 400 and 402 with two phase plates are shown. In various examples, one or both phase plates can be combined with additional optical power, aberration correction, color correction, and / or other optical adjustments besides cylindrical optical power. The combined effect of the phase plates may still depend on the rotation of the phase plates.

[0040] like Figure 4 As shown, lookup table 404 can provide rotation values ​​for implementing various parameters. In one example, lookup table 404 can provide clock angles (e.g., in degrees) as rotation values ​​used to obtain the effective cylindrical power (e.g., diopter) from the combined phase plates. Therefore, given an input parameter corresponding to diopter, the corresponding rotation value of the phase plate can be determined using lookup table 404.

[0041] Figure 5 A pancake lens 500 is shown, which may include, according to Figure 1 Method 100 configures the viewing optics and / or can correspond to Figure 2 Example of device 200. For example, pancake lens 500 can project an image from display 502 onto user's eye 504 through a folded optical path that generates light 514. Figure 5 As shown, the pancake lens 500 assembly may include a pair of rotatable phase plates 506 and 508. In one example, the phase plates may be implemented as Pancharatnam-Berry Phase (PBP) lens surfaces. In some examples, the reflective polarizing lens 510 of the pancake lens 500 (e.g., a defocusing mechanism) may be translated along the optical axis to provide spherical focus adjustment. The phase plates 506 and 508 may be positioned at any of a plurality of locations in the optical stack of the pancake lens 500, including before and / or after any or all of the lenses 510 and 512 of the pancake lens 500.

[0042] Applications of the aforementioned devices, systems, and methods include augmented reality devices and virtual reality devices. Example devices may allow for autofocus adjustment to reduce convergence-autofocus conflict. Examples also include other devices, methods, systems, and computer-readable media.

[0043] Examples also include computer-implemented methods corresponding to, for example, the methods described herein. Example methods include computer-implemented methods for operating or manufacturing devices (e.g., the various devices described herein). Steps of the example methods (e.g., displaying virtual reality or augmented reality elements to a user) can be performed by any suitable computer-executable code and / or computing system. In some examples, one or more steps of the example methods can represent an algorithm whose structure includes and / or can be represented by multiple sub-steps. In some examples, a non-transitory computer-readable medium includes one or more computer-executable instructions that, when executed by at least one processor of a computing device, cause the computing device to perform methods as described herein, such as driving an electronic display (e.g., a liquid crystal display) where display light is transmitted to a user as described herein. In some examples, computer-implemented methods can include, for example, the methods described herein. In some examples, methods for operating devices (e.g., AR / VR devices) can include computer control of the device. In some examples, a non-transitory computer-readable medium may include one or more computer-executable instructions that, when executed by at least one processor of a device, cause the device to operate an electronic device (e.g., an AR / VR device) using methods described herein, for example.

[0044] Example couplers can couple light propagating along a waveguide to an out-of-plane direction, for example, to guide display light propagating along the waveguide to a user's eye. Example couplers can include any one or more of the following: grating couplers; arrangements of scatterers; anti-reflective coatings; other grating structures; or holographic optical elements (HOEs). Example grating couplers can have one-dimensional (1D), two-dimensional (2D), or three-dimensional (3D) grating profiles, and the grating couplers can be directly etched into the waveguide or can be separated from but close to the waveguide. For example, evanescent optical coupling can exist between the waveguide and the grating coupler. Arrangements of scatterers (e.g., arrays) can include non-resonant and / or resonant structures and can be fabricated close to one or more waveguide layers. Scatterers can include meta-grating scatterers, such as multilayer and / or resonant scatterers. An anti-reflective (AR) coating can be formed on the other side of the waveguide to improve coupling efficiency and reduce unwanted light leakage and loss. Example AR coatings may include one or more stacked dielectric, metal, or semiconductor material layers. Grating structures may include volume Bragg gratings. Holographic optical elements (HOEs) may include any suitable optical element, such as liquid crystal-based polarimetric holograms.

[0045] Example couplers may include straight or angled grating elements and / or reflectors, which may be formed on, within, or near the waveguide but separated from it. An example AR coating may be formed on the side of the grating opposite the coupler. In some examples, different couplers may be formed at different locations along the waveguide. For example, an angled grating may be formed near the edge portion of the waveguide.

[0046] In some examples, the projection unit may include an electronic display. Example displays may include any one or more of the following: liquid crystal on silicon (LCOS); ferroelectric LCOS; TFT-LC (thin-film transistor liquid crystal or active matrix configuration); polymer-based EO display panels (e.g., including electroluminescent polymers, polymer-stabilized or encapsulated liquid crystals); and / or display panels based on organic or inorganic semiconductor materials.

[0047] In some examples, the device (e.g., an AR / VR device) may include a liquid crystal display, such as a transmissive LCOS (liquid crystal on silicon), a transmissive ferroelectric liquid crystal on silicon (FLCOS), an active matrix nematic liquid crystal (e.g., a thin-film transistor (TFT) display), or any other suitable display technology. The display may include a nematic liquid crystal display or other liquid crystal displays. In some examples, the light source may include one or more of the following: semiconductor lasers (e.g., laser diodes, vertical-cavity surface-emitting lasers (VCSELs) or other semiconductor lasers), fiber lasers, heterogeneous integrated lasers, light-emitting diodes (LEDs), superluminescent LEDs (SLEDs), and / or nonlinear conversion light sources, such as pump lasers combined with nonlinear optical elements, such as second-harmonic generation (SHG), third-harmonic generation (THG), four-wave mixing (FWM), difference-frequency generation (DFG), and parametric downconversion (PDC). Light sources may illuminate the display in one or more of the following ways: optical fibers; nanowires; free-space edge coupling; waveguide grating couplers; and / or an arrangement of one or more light sources in the backlight unit.

[0048] The embodiments of this disclosure may include various types of artificial reality systems, or combinations thereof. Artificial reality is a form of reality that has been modulated in some way before being presented to a user. This artificial reality may include, for example, virtual reality, augmented reality, mixed reality, or some combination and / or derivative thereof. Artificial reality content may include entirely computer-generated content or computer-generated content combined with acquired (e.g., real-world) content. Artificial reality content may include video, audio, haptic feedback, or some combination thereof, any of which may be presented in a single channel or in multiple channels (e.g., stereoscopic video that provides a three-dimensional (3D) effect to the viewer). Furthermore, in some embodiments, artificial reality may also be associated with applications, products, accessories, services, or some combination thereof used for, for example, creating content in artificial reality and / or otherwise using it in artificial reality (e.g., to perform activities in artificial reality).

[0049] Artificial reality systems can be implemented in a variety of different shapes and configurations. Some artificial reality systems can be designed to operate without a near-eye display (NED). Other artificial reality systems may include NEDs that also provide visibility into the real world (e.g., Figure 6 Augmented reality systems (600) or NEDs that visually immerse users in artificial reality (e.g., Figure 7 (Virtual Reality System 700). While some artificial reality devices may be standalone systems, others may communicate with and / or cooperate with external devices to provide an artificial reality experience to a user. Examples of such external devices include handheld controllers, mobile devices, desktop computers, devices worn by the user, devices worn by one or more other users, and / or any other suitable external system.

[0050] Go to Figure 6 The augmented reality system 600 may include a glasses device 602 with a frame 610 configured to hold a left display device 615(A) and a right display device 615(B) in front of the user's eyes. The left display device 615(A) and the right display device 615(B) may operate together or independently to present an image or a series of images to the user. Although the augmented reality system 600 includes two displays, the various embodiments of this disclosure can be implemented in augmented reality systems having a single NED or more than two NEDs.

[0051] In some examples, the augmented reality system 600 may include one or more sensors, such as sensor 640. Sensor 640 may generate measurement signals in response to motion of the augmented reality system 600, and the sensor may be located on substantially any part of the frame 610. Sensor 640 may represent one or more of a variety of different sensing mechanisms, such as a position sensor, an inertial measurement unit (IMU), a depth camera assembly, a structured light emitter and / or detector, or any combination thereof. In some embodiments, the augmented reality system 600 may or may not include sensor 640, or may include more than one sensor. In examples where sensor 640 includes an IMU, the IMU may generate calibration data based on measurement signals from sensor 640. Examples of sensor 640 may include, but are not limited to, accelerometers, gyroscopes, magnetometers, other suitable types of sensors for detecting motion, sensors for error correction of the IMU, or some combination thereof.

[0052] In some examples, the augmented reality system 600 may also include a microphone array having multiple acoustic transducers 620(A) to 620(J), collectively referred to as acoustic transducers 620. Acoustic transducers 620 may represent transducers that detect changes in air pressure caused by sound waves. Each acoustic transducer 620 may be configured to detect sound and convert the detected sound into an electronic format (e.g., analog or digital). Figure 6 The microphone array may include, for example, ten acoustic transducers: acoustic transducers 620(A) and 620(B) which may be designed to be placed in the corresponding ears of the user; acoustic transducers 620(C), 620(D), 620(E), 620(F), 620(G) and 620(H) which may be positioned at various locations on the frame 610; and / or acoustic transducers 620(I) and 620(J) which may be positioned on the corresponding neckband 605.

[0053] In some embodiments, one or more of the acoustic transducers 620(A) to 620(J) may be used as output transducers (e.g., loudspeakers). For example, acoustic transducers 620(A) and / or 620(B) may be earbuds, or any other suitable type of headphones or loudspeakers.

[0054] The configuration of the acoustic transducers 620 in the microphone array can be varied. Although the augmented reality system 600... Figure 6The array is shown as having ten acoustic transducers 620, but the number of acoustic transducers 620 may be more or less than ten. In some embodiments, using a larger number of acoustic transducers 620 can increase the amount of audio information collected and / or the sensitivity and accuracy of the audio information. In contrast, using a smaller number of acoustic transducers 620 can reduce the computational power required by the associated controller 650 to process the collected audio information. Furthermore, the position of each acoustic transducer 620 in the microphone array can vary. For example, the position of the acoustic transducer 620 may include a defined position on the user, defined coordinates on the frame 610, an orientation associated with each acoustic transducer 620, or some combination thereof.

[0055] Acoustic transducers 620(A) and 620(B) can be positioned on different parts of the user's ear, such as behind the pinna, behind the tragus, and / or within the auricle or fossa. Alternatively, additional acoustic transducers 620 may be present on or around the ear in addition to the acoustic transducers 620 within the ear canal. Positioning the acoustic transducers 620 near the user's ear canal allows the microphone array to collect information about how sound reaches the ear canal. By positioning at least two of the acoustic transducers 620 on either side of the user's head (e.g., as binaural microphones), the augmented reality system 600 can simulate binaural hearing and acquire a 3D stereo sound field around the user's head. In some embodiments, acoustic transducers 620(A) and 620(B) can be connected to the augmented reality system 600 via a wired connection 630, while in other embodiments, acoustic transducers 620(A) and 620(B) can be connected to the augmented reality system 600 via a wireless connection (e.g., Bluetooth connection). In still other embodiments, acoustic transducers 620(A) and 620(B) may not be used in conjunction with the augmented reality system 600 at all.

[0056] The plurality of acoustic transducers 620 on frame 610 can be positioned in a variety of different ways, including along the length of the temples, across the bridge of the nose, above or below display devices 615(A) and 615(B), or some combination thereof. The acoustic transducers 620 can also be oriented such that the microphone array can detect sound in a wide range of directions around a user wearing the augmented reality system 600. In some embodiments, an optimization process can be performed during the manufacture of the augmented reality system 600 to determine the relative positioning of each acoustic transducer 620 in the microphone array.

[0057] In some examples, the augmented reality system 600 may include an external device (e.g., a pairing device) or be able to connect to such an external device, such as a neckband 605. Neckband 605 broadly represents any type or form of pairing device. Therefore, the following discussion of neckband 605 can also be applied to a variety of other pairing devices, such as charging cases, smartwatches, smartphones, wristbands, other wearable devices, handheld controllers, tablets, laptops, other external computing devices, etc.

[0058] As shown in the figure, the neck strap 605 can be coupled to the eyewear device 602 via one or more connectors. The connectors can be wired or wireless and can include electronic components and / or non-electronic (e.g., structural) components. In some cases, the eyewear device 602 and the neck strap 605 can operate independently without any wired or wireless connection between them. Although Figure 6 The illustration shows example locations of components of the eyeglasses device 602 and the neckband 605 on the eyeglasses device 602 and neckband 605, but these components may be located at other locations on the eyeglasses device 602 and / or neckband 605 and / or be distributed differently on the eyeglasses device 602 and / or neckband 605. In some examples, the components of the eyeglasses device 602 and the neckband 605 may be located on one or more additional peripheral devices paired with the eyeglasses device 602, on the neckband 605, or some combination thereof.

[0059] Pairing an external device (e.g., neckband 605) with an augmented reality glasses device allows the glasses device to achieve the shape features of a pair of glasses while still providing sufficient battery power and computing power for the expanded capabilities. Some or all of the battery power, computing resources, and / or additional features of the augmented reality system 600 can be provided by the paired device or shared between the paired device and the glasses device, thereby reducing the overall weight, heat distribution, and shape features of the glasses device while still retaining the desired functionality. For example, the neckband 605 can allow components that would otherwise be included in the glasses device to be incorporated into the neckband 605, as users can bear a heavier weight load on their shoulders compared to the weight load on their head. The neckband 605 can also have a large surface area, through which heat can be diffused and dispersed to the surrounding environment. Therefore, the neckband 605 can allow for a larger battery and computing power than might be achievable on a standalone glasses device. Since the weight carried in the neck strap 605 is less invasive to the user than the weight carried in the eyewear device 602, the user can tolerate wearing the lighter eyewear device and carrying or wearing the paired device for a longer period of time compared to the user having to endure wearing a heavy standalone eyewear device. This allows the user to more fully integrate the artificial reality environment into their daily activities.

[0060] The neckband 605 can be communicatively coupled to the glasses device 602 and / or other devices. These other devices can provide certain functions to the augmented reality system 600 (e.g., tracking, localization, depth mapping, processing, storage, etc.). Figure 6 In some embodiments, the neckband 605 may include two acoustic transducers (e.g., acoustic transducers 620(I) and 620(J)) as part of a microphone array (or potentially forming its own microphone subarray). The neckband 605 may also include a controller 625 and a power supply 635. The acoustic transducers 620(I) and 620(J) in the neckband 605 can be configured to detect sound and convert the detected sound into an electronic format (analog or digital). Figure 6 In some embodiments, acoustic transducers 620(I) and 620(J) may be positioned on the neckband 605, thereby increasing the distance between the acoustic transducers 620(I) and 620(J) on the neckband and other acoustic transducers 620 positioned on the eyewear device 602. In some cases, increasing the distance between the individual acoustic transducers 620 in the microphone array can improve the accuracy of beamforming performed by the microphone array. For example, if acoustic transducers 620(C) and 620(D) detect sound, and the distance between acoustic transducers 620(C) and 620(D) is greater than, for example, the distance between acoustic transducers 620(D) and 620(E), then the determined source location of the detected sound can be more accurate compared to if the sound was detected by acoustic transducers 620(D) and 620(E).

[0061] The controller 625 of the neckband 605 can process information generated by sensors on the neckband 605 and / or the augmented reality system 600. For example, the controller 625 can process information from a microphone array describing sounds detected by the microphone array. For each detected sound, the controller 625 can perform direction-of-arrival (DOA) estimation to estimate the direction of arrival of the detected sound at the microphone array. When the microphone array detects sound, the controller 625 can populate the audio dataset with the information. In embodiments where the augmented reality system 600 includes an inertial measurement unit (IMU), the controller 625 can perform all inertial and spatial calculations based on the IMU located on the glasses device 602. Connectors can transmit information between the augmented reality system 600 and the neckband 605, and between the augmented reality system 600 and the controller 625. This information can be in optical, electronic, wireless, or any other transmissible data format. By transferring the processing of information generated by the augmented reality system 600 to the neckband 605, the weight and heat in the glasses device 602 can be reduced, making the glasses device more comfortable for the user.

[0062] The power source 635 in the neckband 605 can provide power to the eyeglass device 602 and / or to the neckband 605. The power source 635 may include, but is not limited to, a lithium-ion battery, a lithium polymer battery, a disposable lithium battery, an alkaline battery, or any other form of power storage device. In some cases, the power source 635 may be a wired power source. Including the power source 635 on the neckband 605 rather than on the eyeglass device 602 can help to better distribute the weight and heat generated by the power source 635.

[0063] As noted, some artificial reality systems can essentially replace one or more of a user's sensory perceptions of the real world with virtual experiences, rather than blending artificial reality with real reality. An example of this type of system is a head-mounted display system that largely or completely covers the user's field of vision, such as... Figure 7 The virtual reality system 700 may include a front rigid body 702 and a strap 704 shaped to fit around the user's head. The virtual reality system 700 may also include output audio transducers 706(A) and 706(B). Furthermore, although in Figure 7 Not shown, but the front rigid body 702 may include one or more electronic components, including one or more electronic displays, one or more inertial measurement units (IMUs), one or more tracking transmitters or detectors, and / or any other suitable devices or systems for creating artificial reality experiences.

[0064] Artificial reality systems can include various types of visual feedback mechanisms. For example, the display devices in augmented reality system 600 and / or virtual reality system 700 can include one or more liquid crystal displays (LCDs), one or more light-emitting diode (LED) displays, one or more micro-LED displays, one or more organic LED (OLED) displays, one or more digital light projector (DLP) micro-displays, one or more liquid crystal on silicon (LCoS) micro-displays, and / or any other suitable type of display screen. These artificial reality systems can include a single display screen for each eye, or a display screen for each eye, which can provide additional flexibility for zoom adjustment or for correcting the user's refractive errors. Some artificial reality systems may also include optical subsystems with one or more lenses (e.g., concave or convex lenses, Fresnel lenses, adjustable liquid lenses, etc.) through which the user views the display screen. These optical subsystems can be used for a variety of purposes, including collimating light (e.g., making an object appear at a distance greater than its physical distance), magnifying light (e.g., making an object appear larger than its actual size), and / or transmitting light (e.g., delivering light to a viewer's eye). These optical subsystems can be used in non-pupil-forming architectures (e.g., a single-lens configuration that directly collimates light but results in so-called pincushion distortion) and / or pupil-forming architectures (e.g., a multi-lens configuration that produces so-called barrel distortion to eliminate pincushion distortion).

[0065] In addition to or instead of using a display screen, some of the various artificial reality systems described herein may include one or more projection systems. For example, the display device in augmented reality system 600 and / or virtual reality system 700 may include (e.g., using waveguides) a miniature LED projector that projects light onto the display device, such as a transparent combination lens that allows ambient light to pass through. The display device can refract the projected light toward the user's pupil, allowing the user to simultaneously view both the artificial reality content and the real world. This can be achieved using any of a variety of optical components, including waveguide components (e.g., holographic waveguide elements, planar waveguide elements, diffractive waveguide elements, polarizing waveguide elements, and / or reflective waveguide elements), light manipulation surfaces and elements (e.g., diffractive elements and gratings, reflective elements and gratings, and refractive elements and gratings), coupling elements, etc. Artificial reality systems may also be configured with any other suitable type or form of image projection system, such as a retinal projector for a virtual retinal display.

[0066] The artificial reality system described herein may also include various types of computer vision components and subsystems. For example, augmented reality system 600 and / or virtual reality system 700 may include one or more optical sensors, such as two-dimensional (2D) cameras or three-dimensional (3D) cameras, structured light emitters and detectors, time-of-flight depth sensors, single-beam rangefinders or scanning laser rangefinders, 3D lidar (LiDAR) sensors, and / or any other suitable type or form of optical sensor. The artificial reality system may process data from one or more of these sensors to identify the user's location, map the real world, provide the user with context about the real-world environment, and / or perform various other functions.

[0067] The artificial reality system described herein may also include one or more input audio transducers and / or output audio transducers. Output audio transducers may include voice coil loudspeakers, ribbon loudspeakers, electrostatic loudspeakers, piezoelectric loudspeakers, bone conduction transducers, cartilage conduction transducers, tragus vibration transducers, and / or any other suitable type or form of audio transducer. Similarly, input audio transducers may include condenser microphones, dynamic microphones, ribbon microphones, and / or any other type or form of input transducer. In some embodiments, a single transducer may be used for both audio input and audio output.

[0068] In some embodiments, the artificial reality system described herein may also include a tactile (i.e., haptic) feedback system that can be integrated into headwear, gloves, clothing, handheld controllers, environmental devices (e.g., chairs, floor mats, etc.), and / or any other type of device or system. The haptic feedback system can provide various types of skin feedback, including vibration, thrust, tension, texture, and / or temperature. The haptic feedback system can also provide various types of kinematic feedback, such as motion and compliance. Haptic feedback can be implemented using motors, piezoelectric actuators, fluid systems, and / or various other types of feedback mechanisms. The haptic feedback system can be implemented independently of other artificial reality devices, within other artificial reality devices, and / or in conjunction with other artificial reality devices.

[0069] By providing tactile, auditory, and / or visual content, artificial reality (AVR) systems can create complete virtual experiences or enhance a user's real-world experiences in a variety of contexts and environments. For example, AVR systems can assist or extend a user's perception, memory, or cognition within a specific environment. Some systems can enhance a user's interaction with others in the real world or enable more immersive interaction with others in the virtual world. AVR systems can also be used for educational purposes (e.g., for teaching or training in schools, hospitals, businesses, etc.), entertainment purposes (e.g., for playing video games, listening to music, watching video content, etc.), and / or for accessibility purposes (e.g., as hearing aids, visual aids, etc.). The embodiments disclosed herein can realize or enhance a user's AVR experience in one or more of these contexts and environments, and / or in other contexts and environments.

[0070] The process parameters and order of steps described and / or illustrated herein are given by way of example only and may be changed as desired. For example, while the steps shown and / or described herein may be shown or discussed in a particular order, these steps do not necessarily need to be performed in the shown or discussed order. The various exemplary methods described and / or illustrated herein may omit one or more of the steps described or illustrated herein, or may include additional steps in addition to those disclosed.

[0071] Unless otherwise stated, the terms “connected to” and “coupled to” (and their derivatives) as used in this specification and / or claims shall be interpreted as allowing both direct and indirect (i.e., via other elements or components) connections. Furthermore, the terms “a” or “an” as used in the specification and claims shall be interpreted as meaning “at least one”. Finally, for ease of use, the terms “comprising” and “having” (and their derivatives) as used in the specification and claims may be used interchangeably with the word “including” and have the same meaning.

[0072] The foregoing description has been provided to enable those skilled in the art to best utilize various aspects of the exemplary embodiments disclosed herein. This exemplary description is not intended to be exhaustive or limited to any precise form disclosed. Many modifications and variations are possible without departing from the spirit and scope of this disclosure. The embodiments disclosed herein should be considered illustrative rather than restrictive in all respects. Reference should be made to any claims appended herein and their equivalents in determining the scope of this disclosure.

Claims

1. An apparatus comprising: a viewing optic comprising: a first rotatable phase plate; a second rotatable phase plate; and a tunable focal length device; wherein the viewing optic is configured to image light from a display, the imaged light having spherical power, cylindrical power, and a cylindrical axis; and wherein the spherical power, the cylindrical power, and the cylindrical axis of the imaged light are controlled by adjusting the tunable focal length device, rotating the first rotatable phase plate, and rotating the second rotatable phase plate.

2. The apparatus of claim 1, wherein: the viewing optic further comprises a lens; and the tunable focal length device adjusts a position of the lens relative to the display along an optical axis of the viewing optic.

3. The apparatus of claim 1, wherein, the tunable focal length device comprises an active liquid crystal optic.

4. The apparatus of claim 1, wherein, the first rotatable phase plate comprises an astigmatic phase plate.

5. The apparatus of claim 1, wherein, the first rotatable phase plate comprises a Pancharatnam-Berry phase lens surface.

6. The apparatus of claim 1, wherein, the first rotatable phase plate provides aberration correction.

7. The apparatus of claim 1, wherein, the first rotatable phase plate provides color correction.

8. A method comprising: configuring a viewing optic to image light from a display, wherein the viewing optic comprises a first rotatable phase plate, a second rotatable phase plate, and a tunable focal length device, and the imaged light has spherical power, cylindrical power, and a cylindrical axis; and controlling the spherical power, the cylindrical power, and the cylindrical axis of the imaged light by adjusting the tunable focal length device, rotating the first rotatable phase plate, and rotating the second rotatable phase plate.

9. The method of claim 8, wherein, the viewing optic further comprises a lens, and adjusting the tunable focal length device comprises adjusting a position of the lens relative to the display along an optical axis of the tunable focal length device.

10. The method of claim 8, wherein, the tunable focal length device comprises an active liquid crystal optic.

11. The method of claim 8, wherein, the first rotatable phase plate comprises an astigmatic phase plate.

12. The method of claim 8, wherein, the first rotatable phase plate comprises a Pancharatnam-Berry phase lens surface.

13. The method of claim 8, wherein, the first rotatable phase plate provides aberration correction.

14. The method of claim 8, wherein, the first rotatable phase plate provides color correction.

15. A system comprising: a display configured to transmit light; a viewing optic configured to image the light transmitted by the display, wherein the viewing optic comprises a first rotatable phase plate, a second rotatable phase plate, and a tunable focal length device, and the imaged light has spherical power, cylindrical power, and a cylindrical axis; and at least one processor configured to control the spherical power, the cylindrical power, and the cylindrical axis of the imaged light by adjusting the tunable focal length device, rotating the first rotatable phase plate, and rotating the second rotatable phase plate.

16. The system of claim 15, wherein, the viewing optic further comprises a lens, and adjusting the tunable focal length device comprises adjusting a position of the lens relative to the display along an optical axis of the viewing optic.

17. The system of claim 15, wherein, the tunable focal length device comprises an active liquid crystal optic.

18. The system of claim 15, wherein, The first rotatable phase plate comprises an astigmatic phase plate.

19. The system of claim 15, wherein, The first rotatable phase plate comprises a Pancharatnam-Berry phase lens surface.

20. The system of claim 15, wherein, The first rotatable phase plate provides at least one of aberration correction or color correction.

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