The accompanying drawings illustrate a number of example embodiments and are a part of the specification. Together with the following description, these drawings demonstrate and explain various principles of the present disclosure.
Throughout the drawings, identical reference characters and descriptions indicate similar, but not necessarily identical, elements. While the example embodiments described herein are susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and will be described in detail herein. However, the example embodiments described herein are not intended to be limited to the particular forms disclosed. Rather, the present disclosure covers all modifications, equivalents, and alternatives falling within this disclosure.
Imaging lenses utilized in display devices may be limited by various optical aberrations. One such aberration is known as field curvature, which can be described as a predisposition to focus light at a curved image “plane” (i.e., field surface), rather than a flat plane. Field curvature is typically attributed to curved focusing surfaces of optical elements, which project images in a curved, rather than flat, manner. The effect of the field curvature aberration may be more pronounced in regions further from the optical axis of a focusing lens. In some display systems, field curvature has been compensated by using additional optical elements and surfaces within the systems. However, the inclusion of additional optical elements can be size, weight, and cost prohibitive for various display devices. In headset display systems (e.g., virtual-reality headsets, augmented-reality headsets, etc.), field curvature may be resolved, for example, using certain lenses (e.g., Fresnel lenses, pancake lenses, etc.) that inherently compensate for field curvature. However, such lenses may produce stray light and/or diffraction effects that can reduce contrast and/or cause image artifacts. Additionally, display brightness may be undesirably degraded in virtual-reality devices due to low transmission efficiency and non-ideal coatings utilized in some cases may present contrast challenges. Some lenses may also be cost-prohibitive due to high tolerances required by their alignment sensitivity. While curved displays may address field curvature aberrations, such displays suitable for use in various systems, including virtual-reality systems, are not commonly available.
The present disclosure is generally directed to display systems and devices including curved diffusers that may compensate for optical aberrations, such as field curvature aberrations, while providing a sufficiently large eye box for users of the devices. The curved diffusers may enable the use of relatively small projectors and displays without requiring additional optical components to provide a suitably large eye box. A curved reflective or transmissive diffuser may follow a curved path that matches the field curvatures of both projected light incident on the diffuser and the viewing optics to which the diffused light is transmitted. Accordingly, curved diffusers may be utilized to increase the cone angle of light output from displays or projectors to accommodate viewing optics for presenting images covering an increased field of view for users.
Features from any of the embodiments described herein may be used in combination with one another in accordance with the general principles described herein. These and other embodiments, features, and advantages will be more fully understood upon reading the following detailed description in conjunction with the accompanying drawings and claims.
The following will provide, with reference to
As shown in
Curved diffusers, as described herein, may include any suitable type of reflective and/or transmissive diffusers having one or more curved surfaces for reflecting and/or transmitting diffused light. In some examples, a diffuser may have a reflective or semi-reflective surface, such as a metallic surface, having surface features (e.g., regular or irregular surface structures) that are configured to enlarge the cone angle of reflected light. In at least one example, a reflective diffuser may include a transmissive or semi-transmissive diffusing layer coating a reflective surface. In some examples, a transmissive diffuser may be at least partially transmissive and may be configured to enlarge the cone angle of light passing through the diffuser. A transmissive or partially transmissive diffusing material may include any suitable material or combination of materials, including additives such as diffractive particles. The diffusing material may additionally or alternatively include surface features and/or internal features that diffuse light passing through the diffusing layer. In at least one example, correlations between surface and/or internal features (e.g., feature diameters, surface roughness, patterning, etc.) may be used to produce curved diffusers that diffuse light to a specified extent, resulting in a desired degree of increase in light cone angles. In at least one example, a thickness and/or or volume of the curved diffuser and/or a diffusing layer coating a reflective surface of the curved diffuser may be selected to diffuse light to a desired extent without degrading image contrast and/or focus (e.g., a layer may be selected to provide a desired amount of light diffusion while remaining suitably thin so as to avoid a noticeable impact to image quality).
Curved reflective diffuser 220 may be located such that intermediate image 232 is focused on concave intermediate image surface 234. Curved reflective diffuser 220 may diffuse the projected light 224 from display device 222 to expand the cone angle (i.e., increase the etendue) of light reflected from intermediate image surface 234 toward viewing optics 238 of display system 200. Viewing optics 238 may include one or more lenses and/or other optical components configured to produce a final image viewable by a user of display system 200. The expanded cone angle of diffused light reflected from intermediate image surface 234 of curved reflective diffuser 220 is represented by expanded light cone 242 in
Viewing optics 238 may direct the expanded light from curved reflective diffuser 220 toward eye box 240, as shown in
The curvature of intermediate image surface 234 of curved reflective diffuser 220 may be configured to compensate for field curvature of both projection path 302 and viewing path 304. Projected light 224 from display device 222 that is focused on intermediate image surface 234 of curved reflective diffuser 220 may be diffused during reflection. Accordingly, the relatively smaller projected light cone 226 of projected light 224 from display device 222 may be diffused and reflected by intermediate image surface 234 as an expanded light cone 242 toward viewing optics 238, enabling viewing optics 238 to form a sufficiently large eye box 240 for the user.
In some examples, viewing optics 438 may include and/or may be utilized in conjunction with a beamsplitter, such as a beamsplitter having pancake surfaces 448 as illustrated in
While
Light 556 from light source 550 focused on or directed to concave intermediate image surface 534 of curved diffuser 520 by concave intermediate image surface 534 may then be diffused as it is reflected by curved diffuser 520 (see, e.g., curved reflective diffuser 220 shown in
Light focused on intermediate image surface 634 of curved diffuser 620 may be diffused as it is reflected by curved diffuser 620 (see, e.g., the curved reflective diffuser shown in
At operation 720, a curved diffuser may be positioned so that light emitted from the display device is focused on a concave surface of the curved diffuser. Operation 720 may be performed in a variety of ways. For example, light from a projector or small display (e.g., an LED display) may be focused on a concave intermediate image surface of the curved diffuser in any of the ways disclosed herein. The curved diffuser may include a reflective or transmissive diffuser that is positioned to emit diffused light toward any suitable viewing optics, as described herein. In some examples, the curved diffuser may be mounted within an enclosed portion of the display system, such a location within a headset housing that also encloses the display device.
At operation 730, viewing optics may be positioned so that light output from the curved diffuser is directed to an eye box of the display system. Operation 730 may be performed in a variety of ways. The curved diffuser may reflect or transmit diffused light toward the viewing optics, as described herein. The viewing optics may direct the light received from the curved differ to an eye box of the display system that is viewable to a user while wearing the display system. In additional embodiments, other components of the display system, as explained and described above with reference to
Accordingly, the present disclosure includes display systems, devices, and methods that include curved diffusers that enable a sufficiently large eye box to be produced for users using a variety of display devices, including smaller display devices and projectors. The curved diffusers enable the use of relatively small projectors and displays devices without requiring additional optical components to provide the suitably large eye box. A curved reflective or transmissive diffuser may follow a curved path that matches the field curvatures of both projected light incident on the diffuser and viewing optics to which the diffused light is transmitted. Accordingly, curved diffusers may be utilized to increase the cone angle of light output from displays or projectors to accommodate viewing optics for presenting images covering an increased field of view to users.
Example 1: A display system includes 1) a diffuser having a curved surface, 2) a display device positioned to emit light that is focused on the curved surface of the diffuser, 3) at least one viewing optic, and 4) an eye box, where i) the light focused on the curved surface of the diffuser has a first cone angle and is diffused by the diffuser such that light output from the diffuser has a second cone angle, ii) the second cone angle is larger than the first cone angle, and iii) the light output from the diffuser propagates through the at least one viewing optic to the eye box.
Example 2: The display system of Example 1, where the diffuser is reflective.
Example 3: The display system of Example 2, further including a beamsplitter positioned between the diffuser and the eye box, where the light emitted from the display device is reflected from a surface of the beamsplitter toward the curved surface of the diffuser, and the light output from the diffuser transmits through the beamsplitter
Example 4: The display system of Example 1, where the diffuser is transmissive.
Example 5: The display system of any of Examples 1-4, where the light emitted from the display device and focused on the curved surface of the diffuser forms an intermediate image on the curved surface of the diffuser.
Example 6: The display system of any of Examples 1-5, where the light that propagates through the at least one viewing optic forms a final image that is viewable at the eye box.
Example 7: The display system of any of Examples 1-6, where the display device is a projector having a scanning mirror and the scanning mirror reflects light from the projector toward the diffuser.
Example 8: The display system of Example 7, where the projector includes a focusing optic to focus light from the light source toward the scanning mirror.
Example 9: The display system of Example 7, where the projector includes a laser emitter.
Example 10: The display system of any of Examples 1-9, where the display device includes at least one of a light-emitting diode (LED) display or a μLED display.
Example 11: The display system of any of Examples 1-10, where the display device includes at least one of a laser projector or an LED projector.
Example 12: The display system of any of Examples 1-11, where the intermediate image is formed on a concave surface of the diffuser.
Example 13: The display system of Example 12, where the diffuser is transmissive and the light forming the intermediate image on the concave surface of the diffuser propagates through the diffuser and is output from a convex surface of the diffuser.
Example 14: The display system of Example 12, where the concave surface of the diffuser is reflective and the light forming the intermediate image on the concave surface of the diffuser is reflected from the reflective surface of the diffuser.
Example 15: The display system of Example 14, where the light forming the intermediate image on the concave surface of the diffuser is diffused through a layer coating the reflective surface of the diffuser.
Example 16: The display system of Example 14, where the at least one viewing optic further includes a beamsplitter
Example 17: A display system includes a diffuser having a curved surface and a display device positioned to emit light that is focused on the curved surface of the diffuser, where the light focused on the curved surface of the diffuser has a first cone angle and is diffused by the diffuser such that light output from the diffuser has a second cone angle and the second cone angle is larger than the first cone angle.
Example 18: The display system of Example 17, where the diffuser is reflective.
Example 19: The display system of Example 17, where the diffuser is transmissive.
Example 20: A method that includes 1) positioning a display device, 2) positioning a curved diffuser so that light emitted from the display device is focused on a concave surface of the curved diffuser, and 3) positioning viewing optics so that light output from the curved diffuser is directed to an eye box of the display system.
Embodiments of the present disclosure may include or be implemented in conjunction with various types of artificial-reality systems. Artificial reality is a form of reality that has been adjusted in some manner before presentation to a user, which may include, for example, a virtual reality, an augmented reality, a mixed reality, a hybrid reality, or some combination and/or derivative thereof. Artificial-reality content may include completely computer-generated content or computer-generated content combined with captured (e.g., real-world) content. The 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 (such as stereo video that produces a three-dimensional (3D) effect to the viewer). Additionally, in some embodiments, artificial reality may also be associated with applications, products, accessories, services, or some combination thereof, that are used to, for example, create content in an artificial reality and/or are otherwise used in (e.g., to perform activities in) an artificial reality.
Artificial-reality systems may be implemented in a variety of different form factors and configurations. Some artificial-reality systems may be designed to work without near-eye displays (NEDs). Other artificial-reality systems may include an NED that also provides visibility into the real world (such as, e.g., augmented-reality system 800 in
Turning to
In some embodiments, augmented-reality system 800 may include one or more sensors, such as sensor 840. Sensor 840 may generate measurement signals in response to motion of augmented-reality system 800 and may be located on substantially any portion of frame 810. Sensor 840 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, augmented-reality system 800 may or may not include sensor 840 or may include more than one sensor. In embodiments in which sensor 840 includes an IMU, the IMU may generate calibration data based on measurement signals from sensor 840. Examples of sensor 840 may include, without limitation, accelerometers, gyroscopes, magnetometers, other suitable types of sensors that detect motion, sensors used for error correction of the IMU, or some combination thereof.
In some examples, augmented-reality system 800 may also include a microphone array with a plurality of acoustic transducers 820(A)-820(J), referred to collectively as acoustic transducers 820. Acoustic transducers 820 may represent transducers that detect air pressure variations induced by sound waves. Each acoustic transducer 820 may be configured to detect sound and convert the detected sound into an electronic format (e.g., an analog or digital format). The microphone array in
In some embodiments, one or more of acoustic transducers 820(A)-(J) may be used as output transducers (e.g., speakers). For example, acoustic transducers 820(A) and/or 820(B) may be earbuds or any other suitable type of headphone or speaker.
The configuration of acoustic transducers 820 of the microphone array may vary. While augmented-reality system 800 is shown in
Acoustic transducers 820(A) and 820(B) may 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. Or, there may be additional acoustic transducers 820 on or surrounding the ear in addition to acoustic transducers 820 inside the ear canal. Having an acoustic transducer 820 positioned next to an ear canal of a user may enable the microphone array to collect information on how sounds arrive at the ear canal. By positioning at least two of acoustic transducers 820 on either side of a user's head (e.g., as binaural microphones), augmented-reality device 800 may simulate binaural hearing and capture a 3D stereo sound field around about a user's head. In some embodiments, acoustic transducers 820(A) and 820(B) may be connected to augmented-reality system 800 via a wired connection 830, and in other embodiments acoustic transducers 820(A) and 820(B) may be connected to augmented-reality system 800 via a wireless connection (e.g., a BLUETOOTH connection). In still other embodiments, acoustic transducers 820(A) and 820(B) may not be used at all in conjunction with augmented-reality system 800.
Acoustic transducers 820 on frame 810 may be positioned in a variety of different ways, including along the length of the temples, across the bridge, above or below display devices 815(A) and 815(B), or some combination thereof. Acoustic transducers 820 may also be oriented such that the microphone array is able to detect sounds in a wide range of directions surrounding the user wearing the augmented-reality system 800. In some embodiments, an optimization process may be performed during manufacturing of augmented-reality system 800 to determine relative positioning of each acoustic transducer 820 in the microphone array.
In some examples, augmented-reality system 800 may include or be connected to an external device (e.g., a paired device), such as neckband 805. Neckband 805 generally represents any type or form of paired device. Thus, the following discussion of neckband 805 may also apply to various other paired devices, such as charging cases, smart watches, smart phones, wrist bands, other wearable devices, hand-held controllers, tablet computers, laptop computers, other external compute devices, etc.
As shown, neckband 805 may be coupled to eyewear device 802 via one or more connectors. The connectors may be wired or wireless and may include electrical and/or non-electrical (e.g., structural) components. In some cases, eyewear device 802 and neckband 805 may operate independently without any wired or wireless connection between them. While
Pairing external devices, such as neckband 805, with augmented-reality eyewear devices may enable the eyewear devices to achieve the form factor of a pair of glasses while still providing sufficient battery and computation power for expanded capabilities. Some or all of the battery power, computational resources, and/or additional features of augmented-reality system 800 may be provided by a paired device or shared between a paired device and an eyewear device, thus reducing the weight, heat profile, and form factor of the eyewear device overall while still retaining desired functionality. For example, neckband 805 may allow components that would otherwise be included on an eyewear device to be included in neckband 805 since users may tolerate a heavier weight load on their shoulders than they would tolerate on their heads. Neckband 805 may also have a larger surface area over which to diffuse and disperse heat to the ambient environment. Thus, neckband 805 may allow for greater battery and computation capacity than might otherwise have been possible on a stand-alone eyewear device. Since weight carried in neckband 805 may be less invasive to a user than weight carried in eyewear device 802, a user may tolerate wearing a lighter eyewear device and carrying or wearing the paired device for greater lengths of time than a user would tolerate wearing a heavy standalone eyewear device, thereby enabling users to more fully incorporate artificial-reality environments into their day-to-day activities.
Neckband 805 may be communicatively coupled with eyewear device 802 and/or to other devices. These other devices may provide certain functions (e.g., tracking, localizing, depth mapping, processing, storage, etc.) to augmented-reality system 800. In the embodiment of
Acoustic transducers 820(1) and 820(J) of neckband 805 may be configured to detect sound and convert the detected sound into an electronic format (analog or digital). In the embodiment of
Controller 825 of neckband 805 may process information generated by the sensors on neckband 805 and/or augmented-reality system 800. For example, controller 825 may process information from the microphone array that describes sounds detected by the microphone array. For each detected sound, controller 825 may perform a direction-of-arrival (DOA) estimation to estimate a direction from which the detected sound arrived at the microphone array. As the microphone array detects sounds, controller 825 may populate an audio data set with the information. In embodiments in which augmented-reality system 800 includes an inertial measurement unit, controller 825 may compute all inertial and spatial calculations from the IMU located on eyewear device 802. A connector may convey information between augmented-reality system 800 and neckband 805 and between augmented-reality system 800 and controller 825. The information may be in the form of optical data, electrical data, wireless data, or any other transmittable data form. Moving the processing of information generated by augmented-reality system 800 to neckband 805 may reduce weight and heat in eyewear device 802, making it more comfortable to the user.
Power source 835 in neckband 805 may provide power to eyewear device 802 and/or to neckband 805. Power source 835 may include, without limitation, lithium ion batteries, lithium-polymer batteries, primary lithium batteries, alkaline batteries, or any other form of power storage. In some cases, power source 835 may be a wired power source. Including power source 835 on neckband 805 instead of on eyewear device 802 may help better distribute the weight and heat generated by power source 835.
As noted, some artificial-reality systems may, instead of blending an artificial reality with actual reality, substantially replace one or more of a user's sensory perceptions of the real world with a virtual experience. One example of this type of system is a head-worn display system, such as virtual-reality system 900 in
Artificial-reality systems may include a variety of types of visual feedback mechanisms. For example, display devices in augmented-reality system 800 and/or virtual-reality system 900 may include one or more liquid crystal displays (LCDs), light emitting diode (LED) displays, microLED displays, organic LED (OLED) displays, digital light project (DLP) micro-displays, liquid crystal on silicon (LCoS) micro-displays, and/or any other suitable type of display screen. These artificial-reality systems may include a single display screen for both eyes or may provide a display screen for each eye, which may allow for additional flexibility for varifocal adjustments or for correcting a user's refractive error. Some of these artificial-reality systems may also include optical subsystems having one or more lenses (e.g., concave or convex lenses, Fresnel lenses, adjustable liquid lenses, etc.) through which a user may view a display screen. These optical subsystems may serve a variety of purposes, including to collimate (e.g., make an object appear at a greater distance than its physical distance), to magnify (e.g., make an object appear larger than its actual size), and/or to relay (to, e.g., the viewer's eyes) light. These optical subsystems may be used in a non-pupil-forming architecture (such as a single lens configuration that directly collimates light but results in so-called pincushion distortion) and/or a pupil-forming architecture (such as a multi-lens configuration that produces so-called barrel distortion to nullify pincushion distortion).
In addition to or instead of using display screens, some of the artificial-reality systems described herein may include one or more projection systems. For example, display devices in augmented-reality system 800 and/or virtual-reality system 900 may include micro-LED projectors that project light (using, e.g., a waveguide) into display devices, such as clear combiner lenses that allow ambient light to pass through. The display devices may refract the projected light toward a user's pupil and may enable a user to simultaneously view both artificial-reality content and the real world. The display devices may accomplish this using any of a variety of different optical components, including waveguide components (e.g., holographic, planar, diffractive, polarized, and/or reflective waveguide elements), light-manipulation surfaces and elements (such as diffractive, reflective, 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 retinal projectors used in virtual retina displays.
The artificial-reality systems described herein may also include various types of computer vision components and subsystems. For example, augmented-reality system 800 and/or virtual-reality system 900 may include one or more optical sensors, such as two-dimensional (2D) or 3D cameras, structured light transmitters and detectors, time-of-flight depth sensors, single-beam or sweeping laser rangefinders, 3D LiDAR sensors, and/or any other suitable type or form of optical sensor. An artificial-reality system may process data from one or more of these sensors to identify a location of a user, to map the real world, to provide a user with context about real-world surroundings, and/or to perform a variety of other functions.
The artificial-reality systems described herein may also include one or more input and/or output audio transducers. Output audio transducers may include voice coil speakers, ribbon speakers, electrostatic speakers, piezoelectric speakers, 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.
In some embodiments, the artificial-reality systems described herein may also include tactile (i.e., haptic) feedback systems, which may be incorporated into headwear, gloves, body suits, handheld controllers, environmental devices (e.g., chairs, floormats, etc.), and/or any other type of device or system. Haptic feedback systems may provide various types of cutaneous feedback, including vibration, force, traction, texture, and/or temperature. Haptic feedback systems may also provide various types of kinesthetic feedback, such as motion and compliance. Haptic feedback may be implemented using motors, piezoelectric actuators, fluidic systems, and/or a variety of other types of feedback mechanisms. Haptic feedback systems may be implemented independent of other artificial-reality devices, within other artificial-reality devices, and/or in conjunction with other artificial-reality devices.
By providing haptic sensations, audible content, and/or visual content, artificial-reality systems may create an entire virtual experience or enhance a user's real-world experience in a variety of contexts and environments. For instance, artificial-reality systems may assist or extend a user's perception, memory, or cognition within a particular environment. Some systems may enhance a user's interactions with other people in the real world or may enable more immersive interactions with other people in a virtual world. Artificial-reality systems may also be used for educational purposes (e.g., for teaching or training in schools, hospitals, government organizations, military organizations, business enterprises, 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 may enable or enhance a user's artificial-reality experience in one or more of these contexts and environments and/or in other contexts and environments.
The process parameters and sequence of the steps described and/or illustrated herein are given by way of example only and can be varied as desired. For example, while the steps illustrated and/or described herein may be shown or discussed in a particular order, these steps do not necessarily need to be performed in the order illustrated or discussed. The various example methods described and/or illustrated herein may also omit one or more of the steps described or illustrated herein or include additional steps in addition to those disclosed.
The preceding description has been provided to enable others skilled in the art to best utilize various aspects of the example embodiments disclosed herein. This example description is not intended to be exhaustive or to be limited to any precise form disclosed. Many modifications and variations are possible without departing from the spirit and scope of the present disclosure. The embodiments disclosed herein should be considered in all respects illustrative and not restrictive. Reference should be made to any claims appended hereto and their equivalents in determining the scope of the present disclosure.
Unless otherwise noted, the terms “connected to” and “coupled to” (and their derivatives), as used in the specification and/or claims, are to be construed as permitting both direct and indirect (i.e., via other elements or components) connection. In addition, the terms “a” or “an,” as used in the specification and/or claims, are to be construed as meaning “at least one of.” Finally, for ease of use, the terms “including” and “having” (and their derivatives), as used in the specification and/or claims, are interchangeable with and have the same meaning as the word “comprising.”
Number | Date | Country | |
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63392472 | Jul 2022 | US |