Patent Application
20240198578
This disclosure relates in general to imprint lithography on curved surfaces, for example, surfaces of curved waveguides.
It may be desirable to pattern micro-patterns or nano-patterns on curved surfaces. For example, fabricating a curved waveguide for a mixed reality (MR) device may include patterning micro-patterns or nano-patterns on a curved surface (e.g., a curved waveguide substrate), and the patterns may improve presentation of MR content on the device. The process of patterning micro-patterns or nano-patterns on curved surfaces may not be straightforward because conventional patterning processes (e.g., substrate thickness control (e.g., photo-lithography), total thickness variation (TTV), using a rigid super substrate (e.g., a template) may not reliably fabricate these patterns on a curved surface. For example, the conventional processes may lack an ability to control volume of curable material dispensed over such surfaces (e.g., on a substrate, under the superstrate).
To reliably and efficiently fabricate these patterns on a curved surface, an understanding of patterning mechanisms may be required. For example, some process parameters may not be flexible, while some other process parameters may be flexible. Identification of tunable parameters that may be optimized and allowing the parameters to be tuned may permit these patterns to be effectively fabricated on curved surfaces.
Methods for creating a pattern on a curved surface and an optical structure (e.g., curved waveguide, a lens having an antireflective feature, an optical structure of a wearable head device) are disclosed. In some embodiments, a method comprises: depositing a patterning material on a curved surface; positioning a superstrate over the patterning material, the superstrate comprising a template for creating a pattern; applying, using the patterning material, a force between the curved surface and the superstrate; curing the patterning material, wherein the cured patterning material comprises the pattern; and removing the superstrate.
In some embodiments, the method further comprises forming an optical structure using the pattern.
In some embodiments, the optical structure is formed by using the pattern to mold a curable resin.
In some embodiments, the optical structure comprises a curved waveguide.
In some embodiments, the pattern corresponds to a focal point of the curved waveguide.
In some embodiments, the optical structure comprises a lens having an antireflective feature corresponding to the pattern.
In some embodiments, the curved surface comprises one or more nano-channel arrangements.
In some embodiments, each of the one or more nano-channel arrangements is arranged at an angle of zero degree, twelve degrees, or twenty-two degrees relative to an edge of the curved surface.
In some embodiments, the method further comprises spreading the patterning material over the nano-channel arrangements.
In some embodiments, the force comprises a capillary force.
In some embodiments, the force is based on a thickness of the patterning material, a contact angle of patterning material, or both.
In some embodiments, the force maintains a position of the applied superstrate relative to the curved surface.
In some embodiments, depositing the patterning material on the curved surface comprises inkjetting the patterning material.
In some embodiments, positioning the superstrate over the patterning material comprises applying a force on the superstrate to bend the superstrate toward the curved surface.
In some embodiments, the force on the superstrate is applied using a roller or a mechanism.
In some embodiments, the force on the superstrate maintains a distance between the superstrate and the curved surface, and the distance corresponds to the applied force.
In some embodiments, the method further comprises ceasing applying the force on the superstrate after the force between the curved surface and the superstrate is applied using the patterning material.
In some embodiments, the superstrate comprises a flexible coated resist template.
In some embodiments, the superstrate comprises PC, polyethylene terephthalate, or both.
In some embodiments, the superstrate has a thickness of 50-550 μm.
In some embodiments, the superstrate has an elastic modulus less than 10 GPa.
In some embodiments, the method further comprises coating the pattern with a release layer.
In some embodiments, the method further comprises bonding the patterning material with the curved surface via a covalent bond.
In some embodiments, the first patterning material has a first volume, and the first patterning material is deposited at a first location with respect to the curved surface. The method further comprises depositing a second patterning material having a second volume at a second location with respect to the curved surface. A first thickness of the first patterning material at the first location corresponds to a thickness of the first volume, and a second thickness of the second patterning material at the second location corresponds to a thickness of the second volume.
In some embodiments, the first patterning material comprises a first material, and the first patterning material is deposited at a first location with respect to the curved surface. The method further comprises depositing a second patterning material comprising a second material at a second location with respect to the curved surface. A first thickness of the first patterning material at the first location corresponds to a property of the first material, and a second thickness of the second patterning material at the second location corresponds to a property of the second material.
In some embodiments, the first patterning material is deposited at a plurality of first locations of the curved surface, the first locations separated by first intervals, and the cured patterning material further comprises a second pattern. The method further comprises depositing a second patterning material at a plurality of second locations of the curved surface, the second locations separated by second intervals. The first intervals correspond to a first thickness for applying the first force for creating the first pattern, and the second intervals correspond to a second thickness for applying a second force for creating the second pattern.
In some embodiments, the method further comprises transferring, via etching, the pattern onto the curved surface.
In some embodiments, an optical stack comprises an optical feature. The optical feature is formed using any of the above methods.
In some embodiments, a system comprises: a wearable head device comprising a display. The display comprises an optical stack comprising an optical feature, and the optical feature is formed using any of the above methods; and one or more processors configured to execute a method comprising: presenting, on the display, content associated with a mixed reality environment, wherein the content is presented based on the optical feature.
In the following description of examples, reference is made to the accompanying drawings which form a part hereof, and in which it is shown by way of illustration specific examples that can be practiced. It is to be understood that other examples can be used and structural changes can be made without departing from the scope of the disclosed examples.
Like all people, a user of a mixed reality system exists in a real environment—that is, a three-dimensional portion of the “real world,” and all of its contents, that are perceptible by the user. For example, a user perceives a real environment using one's ordinary human senses—sight, sound, touch, taste, smell—and interacts with the real environment by moving one's own body in the real environment. Locations in a real environment can be described as coordinates in a coordinate space; for example, a coordinate can comprise latitude, longitude, and elevation with respect to sea level; distances in three orthogonal dimensions from a reference point; or other suitable values. Likewise, a vector can describe a quantity having a direction and a magnitude in the coordinate space.
A computing device can maintain, for example in a memory associated with the device, a representation of a virtual environment. As used herein, a virtual environment is a computational representation of a three-dimensional space. A virtual environment can include representations of any object, action, signal, parameter, coordinate, vector, or other characteristic associated with that space. In some examples, circuitry (e.g., a processor) of a computing device can maintain and update a state of a virtual environment; that is, a processor can determine at a first time t0, based on data associated with the virtual environment and/or input provided by a user, a state of the virtual environment at a second time t1. For instance, if an object in the virtual environment is located at a first coordinate at time t0, and has certain programmed physical parameters (e.g., mass, coefficient of friction); and an input received from user indicates that a force should be applied to the object in a direction vector; the processor can apply laws of kinematics to determine a location of the object at time t1 using basic mechanics. The processor can use any suitable information known about the virtual environment, and/or any suitable input, to determine a state of the virtual environment at a time t1. In maintaining and updating a state of a virtual environment, the processor can execute any suitable software, including software relating to the creation and deletion of virtual objects in the virtual environment; software (e.g., scripts) for defining behavior of virtual objects or characters in the virtual environment; software for defining the behavior of signals (e.g., audio signals) in the virtual environment; software for creating and updating parameters associated with the virtual environment; software for generating audio signals in the virtual environment; software for handling input and output; software for implementing network operations; software for applying asset data (e.g., animation data to move a virtual object over time); or many other possibilities.
Output devices, such as a display or a speaker, can present any or all aspects of a virtual environment to a user. For example, a virtual environment may include virtual objects (which may include representations of inanimate objects; people; animals; lights; etc.) that may be presented to a user. A processor can determine a view of the virtual environment (for example, corresponding to a “camera” with an origin coordinate, a view axis, and a frustum); and render, to a display, a viewable scene of the virtual environment corresponding to that view. Any suitable rendering technology may be used for this purpose. In some examples, the viewable scene may include some virtual objects in the virtual environment, and exclude certain other virtual objects. Similarly, a virtual environment may include audio aspects that may be presented to a user as one or more audio signals. For instance, a virtual object in the virtual environment may generate a sound originating from a location coordinate of the object (e.g., a virtual character may speak or cause a sound effect); or the virtual environment may be associated with musical cues or ambient sounds that may or may not be associated with a particular location. A processor can determine an audio signal corresponding to a “listener” coordinate—for instance, an audio signal corresponding to a composite of sounds in the virtual environment, and mixed and processed to simulate an audio signal that would be heard by a listener at the listener coordinate—and present the audio signal to a user via one or more speakers.
Because a virtual environment exists as a computational structure, a user may not directly perceive a virtual environment using one's ordinary senses. Instead, a user can perceive a virtual environment indirectly, as presented to the user, for example by a display, speakers, haptic output devices, etc. Similarly, a user may not directly touch, manipulate, or otherwise interact with a virtual environment; but can provide input data, via input devices or sensors, to a processor that can use the device or sensor data to update the virtual environment. For example, a camera sensor can provide optical data indicating that a user is trying to move an object in a virtual environment, and a processor can use that data to cause the object to respond accordingly in the virtual environment.
A mixed reality system can present to the user, for example using a transmissive display and/or one or more speakers (which may, for example, be incorporated into a wearable head device), a mixed reality environment (MRE) that combines aspects of a real environment and a virtual environment. In some embodiments, the one or more speakers may be external to the wearable head device. As used herein, a MRE is a simultaneous representation of a real environment and a corresponding virtual environment. In some examples, the corresponding real and virtual environments share a single coordinate space; in some examples, a real coordinate space and a corresponding virtual coordinate space are related to each other by a transformation matrix (or other suitable representation). Accordingly, a single coordinate (along with, in some examples, a transformation matrix) can define a first location in the real environment, and also a second, corresponding, location in the virtual environment; and vice versa.
In a MRE, a virtual object (e.g., in a virtual environment associated with the MRE) can correspond to a real object (e.g., in a real environment associated with the MRE). For instance, if the real environment of a MRE comprises a real lamp post (a real object) at a location coordinate, the virtual environment of the MRE may comprise a virtual lamp post (a virtual object) at a corresponding location coordinate. As used herein, the real object in combination with its corresponding virtual object together constitute a “mixed reality object.” It is not necessary for a virtual object to perfectly match or align with a corresponding real object. In some examples, a virtual object can be a simplified version of a corresponding real object. For instance, if a real environment includes a real lamp post, a corresponding virtual object may comprise a cylinder of roughly the same height and radius as the real lamp post (reflecting that lamp posts may be roughly cylindrical in shape). Simplifying virtual objects in this manner can allow computational efficiencies, and can simplify calculations to be performed on such virtual objects. Further, in some examples of a MRE, not all real objects in a real environment may be associated with a corresponding virtual object. Likewise, in some examples of a MRE, not all virtual objects in a virtual environment may be associated with a corresponding real object. That is, some virtual objects may solely in a virtual environment of a MRE, without any real-world counterpart.
In some examples, virtual objects may have characteristics that differ, sometimes drastically, from those of corresponding real objects. For instance, while a real environment in a MRE may comprise a green, two-armed cactus—a prickly inanimate object—a corresponding virtual object in the MRE may have the characteristics of a green, two-armed virtual character with human facial features and a surly demeanor. In this example, the virtual object resembles its corresponding real object in certain characteristics (color, number of arms); but differs from the real object in other characteristics (facial features, personality). In this way, virtual objects have the potential to represent real objects in a creative, abstract, exaggerated, or fanciful manner; or to impart behaviors (e.g., human personalities) to otherwise inanimate real objects. In some examples, virtual objects may be purely fanciful creations with no real-world counterpart (e.g., a virtual monster in a virtual environment, perhaps at a location corresponding to an empty space in a real environment).
In some examples, virtual objects hay have characteristics that resemble corresponding real objects. For instance, a virtual character may be presented in a virtual or mixed reality environment as a life-like figure to provide a user an immersive mixed reality experience. With virtual characters having life-like characteristics, the user may feel like he or she is interacting with a real person. In such instances, it is desirable for actions such as muscle movements and gaze of the virtual character to appear natural. For example, movements of the virtual character should be similar to its corresponding real object (e.g., a virtual human should walk or move its arm like a real human). As another example, the gestures and positioning of the virtual human should appear natural, and the virtual human can initial interactions with the user (e.g., the virtual human can lead a collaborative experience with the user). Presentation of virtual characters having life-like characteristics is described in more detail herein.
Compared to virtual reality (VR) systems, which present the user with a virtual environment while obscuring the real environment, a mixed reality system presenting a MRE affords the advantage that the real environment remains perceptible while the virtual environment is presented. Accordingly, the user of the mixed reality system is able to use visual and audio cues associated with the real environment to experience and interact with the corresponding virtual environment. As an example, while a user of VR systems may struggle to perceive or interact with a virtual object displayed in a virtual environment—because, as noted herein, a user may not directly perceive or interact with a virtual environment—a user of an mixed reality (MR) system may find it more intuitive and natural to interact with a virtual object by seeing, hearing, and touching a corresponding real object in his or her own real environment. This level of interactivity may heighten a user's feelings of immersion, connection, and engagement with a virtual environment. Similarly, by simultaneously presenting a real environment and a virtual environment, mixed reality systems may reduce negative psychological feelings (e.g., cognitive dissonance) and negative physical feelings (e.g., motion sickness) associated with VR systems. Mixed reality systems further offer many possibilities for applications that may augment or alter our experiences of the real world.
Persistent coordinate data may be coordinate data that persists relative to a physical environment. Persistent coordinate data may be used by MR systems (e.g., MR system 112, 200) to place persistent virtual content, which may not be tied to movement of a display on which the virtual object is being displayed. For example, a two-dimensional screen may display virtual objects relative to a position on the screen. As the two-dimensional screen moves, the virtual content may move with the screen. In some embodiments, persistent virtual content may be displayed in a corner of a room. A MR user may look at the corner, see the virtual content, look away from the corner (where the virtual content may no longer be visible because the virtual content may have moved from within the user's field of view to a location outside the user's field of view due to motion of the user's head), and look back to see the virtual content in the corner (similar to how a real object may behave).
In some embodiments, persistent coordinate data (e.g., a persistent coordinate system and/or a persistent coordinate frame) can include an origin point and three axes. For example, a persistent coordinate system may be assigned to a center of a room by a MR system. In some embodiments, a user may move around the room, out of the room, re-enter the room, etc., and the persistent coordinate system may remain at the center of the room (e.g., because it persists relative to the physical environment). In some embodiments, a virtual object may be displayed using a transform to persistent coordinate data, which may enable displaying persistent virtual content. In some embodiments, a MR system may use simultaneous localization and mapping to generate persistent coordinate data (e.g., the MR system may assign a persistent coordinate system to a point in space). In some embodiments, a MR system may map an environment by generating persistent coordinate data at regular intervals (e.g., a MR system may assign persistent coordinate systems in a grid where persistent coordinate systems may be at least within five feet of another persistent coordinate system).
In some embodiments, persistent coordinate data may be generated by a MR system and transmitted to a remote server. In some embodiments, a remote server may be configured to receive persistent coordinate data. In some embodiments, a remote server may be configured to synchronize persistent coordinate data from multiple observation instances. For example, multiple MR systems may map the same room with persistent coordinate data and transmit that data to a remote server. In some embodiments, the remote server may use this observation data to generate canonical persistent coordinate data, which may be based on the one or more observations. In some embodiments, canonical persistent coordinate data may be more accurate and/or reliable than a single observation of persistent coordinate data. In some embodiments, canonical persistent coordinate data may be transmitted to one or more MR systems. For example, a MR system may use image recognition and/or location data to recognize that it is located in a room that has corresponding canonical persistent coordinate data (e.g., because other MR systems have previously mapped the room). In some embodiments, the MR system may receive canonical persistent coordinate data corresponding to its location from a remote server.
With respect to
In the example shown, mixed reality objects comprise corresponding pairs of real objects and virtual objects (e.g., 122A/122B, 124A/124B, 126A/126B) that occupy corresponding locations in coordinate space 108. In some examples, both the real objects and the virtual objects may be simultaneously visible to user 110. This may be desirable in, for example, instances where the virtual object presents information designed to augment a view of the corresponding real object (such as in a museum application where a virtual object presents the missing pieces of an ancient damaged sculpture). In some examples, the virtual objects (122B, 124B, and/or 126B) may be displayed (e.g., via active pixelated occlusion using a pixelated occlusion shutter) so as to occlude the corresponding real objects (122A, 124A, and/or 126A). This may be desirable in, for example, instances where the virtual object acts as a visual replacement for the corresponding real object (such as in an interactive storytelling application where an inanimate real object becomes a “living” character).
In some examples, real objects (e.g., 122A, 124A, 126A) may be associated with virtual content or helper data that may not necessarily constitute virtual objects. Virtual content or helper data can facilitate processing or handling of virtual objects in the mixed reality environment. For example, such virtual content could include two-dimensional representations of corresponding real objects; custom asset types associated with corresponding real objects; or statistical data associated with corresponding real objects. This information can enable or facilitate calculations involving a real object without incurring unnecessary computational overhead.
In some examples, the presentation described herein may also incorporate audio aspects. For instance, in MRE 150, virtual character 132 could be associated with one or more audio signals, such as a footstep sound effect that is generated as the character walks around MRE 150. As described herein, a processor of mixed reality system 112 can compute an audio signal corresponding to a mixed and processed composite of all such sounds in MRE 150, and present the audio signal to user 110 via one or more speakers included in mixed reality system 112 and/or one or more external speakers.
Example mixed reality system 112 can include a wearable head device (e.g., a wearable augmented reality or mixed reality head device) comprising a display (which may comprise left and right transmissive displays, which may be near-eye displays, and associated components for coupling light from the displays to the user's eyes); left and right speakers (e.g., positioned adjacent to the user's left and right ears, respectively); an inertial measurement unit (IMU) (e.g., mounted to a temple arm of the head device); an orthogonal coil electromagnetic receiver (e.g., mounted to the left temple piece); left and right cameras (e.g., depth (time-of-flight) cameras) oriented away from the user; and left and right eye cameras oriented toward the user (e.g., for detecting the user's eye movements). However, a mixed reality system 112 can incorporate any suitable display technology, and any suitable sensors (e.g., optical, infrared, acoustic, LIDAR, EOG, GPS, magnetic). In addition, mixed reality system 112 may incorporate networking features (e.g., Wi-Fi capability, mobile network (e.g., 4G, 5G) capability) to communicate with other devices and systems, including neural networks (e.g., in the cloud) for data processing and training data associated with presentation of elements (e.g., virtual character 132) in the MRE 150 and other mixed reality systems. Mixed reality system 112 may further include a battery (which may be mounted in an auxiliary unit, such as a belt pack designed to be worn around a user's waist), a processor, and a memory. The wearable head device of mixed reality system 112 may include tracking components, such as an IMU or other suitable sensors, configured to output a set of coordinates of the wearable head device relative to the user's environment. In some examples, tracking components may provide input to a processor performing a Simultaneous Localization and Mapping (SLAM) and/or visual odometry algorithm. In some examples, mixed reality system 112 may also include a handheld controller 300, and/or an auxiliary unit 320, which may be a wearable beltpack, as described herein.
In some embodiments, an animation rig is used to present the virtual character 132 in the MRE 150. Although the animation rig is described with respect to virtual character 132, it is understood that the animation rig may be associated with other characters (e.g., a human character, an animal character, an abstract character) in the MRE 150. Movement of the animation rig is described in more detail herein.
In some examples, wearable head device 2102 can include a left temple arm 2130 and a right temple arm 2132, where the left temple arm 2130 includes a left speaker 2134 and the right temple arm 2132 includes a right speaker 2136. An orthogonal coil electromagnetic receiver 2138 can be located in the left temple piece, or in another suitable location in the wearable head unit 2102. An Inertial Measurement Unit (IMU) 2140 can be located in the right temple arm 2132, or in another suitable location in the wearable head device 2102. The wearable head device 2102 can also include a left depth (e.g., time-of-flight) camera 2142 and a right depth camera 2144. The depth cameras 2142, 2144 can be suitably oriented in different directions so as to together cover a wider field of view.
In the example shown in
In some examples, as shown in
In some examples, to create a perception that displayed content is three-dimensional, stereoscopically-adjusted left and right eye imagery can be presented to the user through the imagewise light modulators 2124, 2126 and the eyepieces 2108, 2110. The perceived realism of a presentation of a three-dimensional virtual object can be enhanced by selecting waveguides (and thus corresponding the wavefront curvatures) such that the virtual object is displayed at a distance approximating a distance indicated by the stereoscopic left and right images. This technique may also reduce motion sickness experienced by some users, which may be caused by differences between the depth perception cues provided by stereoscopic left and right eye imagery, and the autonomic accommodation (e.g., object distance-dependent focus) of the human eye.
In some examples, mixed reality system 200 can include one or more microphones to detect sound and provide corresponding signals to the mixed reality system. In some examples, a microphone may be attached to, or integrated with, wearable head device 2102, and may be configured to detect a user's voice. In some examples, a microphone may be attached to, or integrated with, handheld controller 300 and/or auxiliary unit 320. Such a microphone may be configured to detect environmental sounds, ambient noise, voices of a user or a third party, or other sounds.
In some embodiments, wearable system 400 can include microphone array 407, which can include one or more microphones arranged on headgear device 400A. In some embodiments, microphone array 407 can include four microphones. Two microphones can be placed on a front face of headgear 400A, and two microphones can be placed at a rear of head headgear 400A (e.g., one at a back-left and one at a back-right). In some embodiments, signals received by microphone array 407 can be transmitted to DSP 408. DSP 408 can be configured to perform signal processing on the signals received from microphone array 407. For example, DSP 408 can be configured to perform noise reduction, acoustic echo cancellation, and/or beamforming on signals received from microphone array 407. DSP 408 can be configured to transmit signals to processor 416.
In some examples, it may become necessary to transform coordinates from a local coordinate space (e.g., a coordinate space fixed relative to the wearable head device 400A) to an inertial coordinate space (e.g., a coordinate space fixed relative to the real environment), for example in order to compensate for the movement of the wearable head device 400A (e.g., of MR system 112) relative to the coordinate system 108. For instance, such transformations may be necessary for a display of the wearable head device 400A to present a virtual object at an expected position and orientation relative to the real environment (e.g., a virtual person sitting in a real chair, facing forward, regardless of the wearable head device's position and orientation), rather than at a fixed position and orientation on the display (e.g., at the same position in the right lower corner of the display), to preserve the illusion that the virtual object exists in the real environment (and does not, for example, appear positioned unnaturally in the real environment as the wearable head device 400A shifts and rotates). In some examples, a compensatory transformation between coordinate spaces can be determined by processing imagery from the depth cameras 444 using a SLAM and/or visual odometry procedure in order to determine the transformation of the wearable head device 400A relative to the coordinate system 108. In the example shown in
In some examples, the depth cameras 444 can supply 3D imagery to a hand gesture tracker 411, which may be implemented in a processor of the wearable head device 400A. The hand gesture tracker 411 can identify a user's hand gestures, for example by matching 3D imagery received from the depth cameras 444 to stored patterns representing hand gestures. Other suitable techniques of identifying a user's hand gestures will be apparent.
In some examples, one or more processors 416 may be configured to receive data from the wearable head device's 6DOF headgear subsystem 404B, the IMU 409, the SLAM/visual odometry block 406, depth cameras 444, and/or the hand gesture tracker 411. The processor 416 can also send and receive control signals from the 6DOF totem system 404A. The processor 416 may be coupled to the 6DOF totem system 404A wirelessly, such as in examples where the handheld controller 400B is untethered. Processor 416 may further communicate with additional components, such as an audio-visual content memory 418, a Graphical Processing Unit (GPU) 420, and/or a Digital Signal Processor (DSP) audio spatializer 422. The DSP audio spatializer 422 may be coupled to a Head Related Transfer Function (HRTF) memory 425. The GPU 420 can include a left channel output coupled to the left source of imagewise modulated light 424 (e.g., for displaying content on left eyepiece 428) and a right channel output coupled to the right source of imagewise modulated light 426 (e.g., for displaying content on right eyepiece 430). GPU 420 can output stereoscopic image data to the sources of imagewise modulated light 424, 426, for example as described herein with respect to
In some examples, such as shown in
While
As light propagates through waveguide layer 504 by total internal reflection (TIR), output light is diffracted out of waveguide layer 504 as illustrated by output rays. For low levels of curvature, input surface 506 and output surface 508 are substantially parallel to each other at positions across the waveguide layer. Accordingly, as light propagates through the waveguide layer by TIR, the parallel nature of the waveguide surfaces preserves the reflection angles during TIR so that the angle between the output ray and the output surface is preserved across the waveguide layer. Since the surface normals vary slightly across the curved waveguide layer output surface, the output rays also vary slightly, producing the divergence illustrated in
The divergence of output rays resulting from the curvature of output surface 508 can have the effect of rendering input light beam 502 so that it appears that light originates from a point source positioned at a particular distance behind waveguide layer 504. Accordingly, the surface profile or curvature of waveguide layer 504 produces a divergence of light toward the user's or viewer's eye 510, effectively rendering the light as originating from a depth plane positioned behind the waveguide layer with respect to the eye.
The distance from the waveguide layer at which the input light beam appears to originate can be associated with the radius of curvature of waveguide layer 504. A waveguide with a higher radius of curvature can render a light source as originating at a greater distance from waveguide layer than a waveguide with a lower radius of curvature. For example, as shown in
In some embodiments, a radius of curvature of the waveguide layer, which can be a polymer waveguide layer, can be dynamically varied between a first distance (e.g., 0.1 m) and infinity, which can dynamically vary the depth planes (i.e., the distance at which a projected light source appears to be rendered) of the eyepiece as well between the first distance and infinity. Thus, embodiments of the present invention enable variation of depth planes between the first distance (e.g., 0.1 m) and infinity, which includes depth planes typically utilized in augmented or mixed reality applications. The surface profile of the waveguide layers, e.g., flexible polymer waveguide layers, can be adjusted using various methodologies and mechanisms as described in more detail herein.
In some embodiments, dynamic eyepieces are provided in which a depth plane of the eyepiece can be varied to display virtual content at different depth planes, for example, temporal variation as a function of time. Accordingly, subsequent frames of virtual content can be displayed, appearing to originate from different depth planes. However, static implementations are also included within the scope of the present invention. In these static implementations, a fixed and predetermined surface profile or curvature characterizes the waveguide layers of the eyepiece, thereby presenting the virtual content at a fixed depth plane. In contrast with some systems utilizing external lenses, diffractive lenses, or other optical elements, embodiments utilizing a static implementation can implement a depth plane through curvature of the waveguide layers, reducing system complexity, and improving optical quality. Moreover, some embodiments can implement a set of eyepieces, each eyepiece including a stack of curved waveguide layers to provide two static depth planes. As an example, a first stack of three curved waveguide layers could utilize a bow of 0.2 mm across the width/length of the waveguide stack to implement a three-color scene at a depth plane positioned at 1 m and a second stack of three curved waveguide layers could utilize a bow of 0.4 mm across the width/length of the waveguide stack to implement a second three-color scene at a depth plane positioned at 0.5 m. Other suitable dimensions are within the scope of the present invention. In addition, binocular systems as well as monocular systems are contemplated.
In some embodiments, disclosed waveguides are as described in U.S. Patent Publication No. US2021/0011305, the entire disclosure of which is herein incorporated by reference. The disclosed waveguides may enhance presentation of images (e.g., mixed reality (MR) content) to a user by improving optical properties in a cost-effective manner.
Therefore, it may be desirable to create micro-patterns or nano-patterns on curved surfaces, for example, to fabricate curved waveguides for MR applications and to achieve the advantages described above, or to create antireflective features on a curved optical structure (e.g., a curved lens with antireflective features). The process of creating micro-patterns or nano-patterns on curved surfaces may not be straightforward. Embodiments of the disclosure describe patterning mechanisms and/or parameters for efficiently creating these patterns on a curved surface.
For example, using a nanoimprint lithography process (e.g., J-FIL) with a coated resist template (CRT) (e.g., a superstrate comprising a template for creating a desired pattern) on flexible plastic, glass web, or sheet may overcome process barriers experienced in conventional processes (e.g., by allowing ability to control volume of the patterning material). Using a nanoimprint lithography process such as J-FIL and a flexible CRT (e.g., glass, plastic, a sheet), as disclosed herein, advantageously allow (1) a material of varying material index and/or volume to be dispensed across any area of a curved surface, and/or (2) a mold (e.g., a thin flexible mold) to conform directly to a surface (e.g., a curved surface) using capillary forces. The capillary forces may be imparted to a thin, controlled volume resist fluid coating, allowing formation of micro-patterns and/or nano-patterns on varying TTV surfaces.
The magnitude of the fluid capillary forces (e.g., associated with the patterning material) may be affected by fluid flow, time of flow, and/or fluid resistance. Fluid mechanics equations may describe these forces and thereby, contact-based imprint principles. The Young-Laplace equation with boundary conditions applied between two surfaces (e.g., between a curved surface and a superstrate) with a patterning material (e.g., resist fluid) and air as media is described in equation (1).
As described in equation (1), force acting on each surface is directly proportional to an area of patterning material interaction between the two surfaces. The area may have a width, w, and length, l. γr may be patterning material (e.g., resist) surface tension in air. The force is inversely proportional to the distance, d, between the two surfaces. In some instances, the distance parameter, d, is of importance as it may dictate the magnitude of force acting on the surfaces. The control of the distance parameter may be dictated by process type for dispensing the patterning material in a specific condition.
Using the Young-Laplace equation and the Navier-Stokes equation for incompressible laminar flow, a time required for capillary fill for a given patterning material may be described in equation (2).
Equation (2) may be further used to understand a magnitude of flow velocity of the laminar flow. The Reynolds number may be calculated, which is the ratio of inertial force over viscous force. For example, the Reynolds number for such flow is at about 10−5, and thus the flow is considered laminar.
Equations (1) and (2) may provide a generalized approximate trend as shown in Table 1. Table 1 shows exemplary forces exerted on a surface based on change in patterning material (e.g., resist fluid) contact angle (wetting (e.g., less than 5 degrees) vs. non-wetting (e.g., greater than 5 degrees)) and volume/thicknesses for a given material surface tension at 30 mN/m. Specifically, Table 1 shows forces in Newtons over a 1 mm×1 mm unit area exerted due to capillary wetting for resist with varying ultra-low volume filling and for resist with varying contact angles.
Table 1 highlights the importance of a patterning material (e.g., a wetting resist fluid) that is capable of being dispensed at low volumes (e.g., corresponding to a thickness less than 50 nm) to achieve high capillary force exerted on surfaces (e.g., greater than or equal 1N per square mm). That is, dispensing the patterning material at a thickness less than 50 nm may achieve capillary forces exerted on surfaces greater than or equal to 1N per square mm. Achieving a high capillary force may allow micro-patterns or nano-patterns to be more efficiently created on curved surfaces, as described in more detail herein.
In some embodiments, the patterning material is a nanoimprint resist that (1) has good wetting characteristics for filling and/or for volume dispense control and/or (2) requires low release force upon curing. For example, the patterning material can be a resist used in J-FIL type processes, where the resist has low viscosity (e.g., less than 20 cP), low contact angle with Si and SiO2 type surfaces (e.g., less than 20 degrees), and a surface tension of around 30 mN/m. As illustrated in Table 1, these conditions may allow for high capillary forces. For example, to provide the low volumes for achieving the high capillary forces, an inkjet is used to dispense less than 500 nL volume of resist over large areas (e.g., 50 mm×50 mm); on average, a drop of less than 6 pL in size is dispensed over a square grid of 180 μm×180 μm.
In some embodiments, the patterning material (e.g., resist fluid) is deposited using inkjetting, which may result in lower surface tension, compared to spincoating or slot-die coating. For example, the lower surface tension may allow the patterning material to spread and fill (e.g., spread and fill a template) faster, compared to spincoated material, which may evaporate. Using inkjetting, the patterning material is advantageously kept in its desired material state and at a lower viscosity, reducing viscous forces. As a result, a lower viscous forces may increase capillary fill time, advantageously increasing capillary force exerted over a large area for imprinting. Additionally, the lower surface tension and lower viscosity of resist material in fluid form achieved by inkjetting may reduce patterning defects such as de-wetting, non-fill, or underfill.
The contact angle and wetting characteristic of the resist, which, as described above, affects capillary force exerted, may be affected by nano-geometry type and the resist's density compared to a blank surface when the resist is in contact. An area comprising nano-channels may help flow of a fluid (e.g., patterning material) in a particular direction. By helping flow of the fluid, the spreading of the patterning material (e.g., resist) may be increased. By increasing spreading, the fluid between the two surfaces (e.g., superstrate and substrate) sandwiching the fluid may be reduced. Reducing the fluid between the two sandwiching surfaces may increase the force (e.g., capillary force) keeping the two surfaces in contact, as described above. As described in more detail herein, methods of applying increased force between two surfaces allow micro-patterns or nano-patterns to be more effectively and reliably created on a curved surface.
The described nano-channel arrangements may improve patterning material filling speed (compared to a surface without the nano-channel arrangements), reducing gap thickness occupied by the patterning material and exerting more capillary force when interacting between two surfaces (e.g., two curved surfaces; a curved substrate and a curved superstrate). In some embodiments, by using a nano-channel arrangement with a same pitch as its width (i.e., a 50% spatial periodicity), micro-patterns or nano-patterns may be improve (e.g., by two times) the capillary hold for a given fill volume (assuming no non-fill voids).
In some embodiments, the curved surface 700 includes nano-channel arrangements, as described with respect to
In some embodiments, locations of the patterning material 702 deposits correspond to a desired pattern (e.g., a micro-pattern, a nano-pattern). For example, a center of a deposited patterning material corresponds to periodicity of a desired pattern (e.g., a pattern pitch) to be molded by a superstrate. Specifically, the locations of the deposits may allow a sufficient capillary force to be applied (as described with respect to equations (1) and (2) and Table 1) for effectively and reliably creating the desired pattern using a CRT. In turn, the desired pattern may become an imprint or a mold for creating optical patterns on a curved optical element (e.g., optical patterns on a curved waveguide, antireflective features on a curved optical element).
Referring back to Table 1, the force magnitude per unit 1 mm×1 mm area may be important while considering a type of superstrate (e.g., CRT) to use for forming an enclosed space filled with the patterning material of a particular volume. For example, these considerations include bending ability of a superstrate and/or maximum deflection of the superstrate due to the bending.
The Euler-Bernoulli beam equation, shown in equation (3), may give an idea of the deflection achieved and/or force required to bend a certain distance for a certain superstrate (e.g., CRT) material type with a specific thickness.
Equation (3) may be used to determine a type of superstrate or CRT to use for forming the enclosed space and creating micro-patterns or nano-patterns, as described herein. In equation (3), q is a constant force over a length L (e.g., length of the superstrate) on a material (e.g., superstrate material) with an elastic modulus E and second moment of area at an axis perpendicular to the loading l. The result of equation (3) yields a maximum deflection DC at a center (e.g., of the CRT). The equation may represent a slice from edge to center, for example, of a spherical imprint (e.g., a lens type profile).
Using equation (3) and understanding the capillary force exerted for holding the curvature (e.g., relationships from Table 1), Table 2 shows that a sub-250 nm resist volume thicknesses may be held. Specifically, Table 2 shows a maximum deflection, in mm, over a 20 mm length of Polycarbonate (PC) based CRT at 50-550 μm thickness with different force exerted, based on Table 1, with specific resist gap thickness and resist contact angle:
In some instances, template demolding may be relied on cured resist surface interaction with the template's surface (e.g., a superstrate's surface), pattern density, and complexity of pattern being created (e.g., re-entrant shapes, sloped sidewalls). The mold-release requirement from the superstrate may depend on adherence to a substrate type. In some embodiments, bonding of the patterning material to the substrate is enhanced chemically via additional covalent bonding.
In some embodiments, the pattern 706 may be used for creating antireflective features (e.g., antireflective nano-patterns) on a lens. For example, the pattern 706 may be part of a mold; a lens and its antireflective patterns may be advantageously formed with the mold (i.e., pattern 706) in one step (e.g., without antireflective film deposition). In some embodiments, the pattern 706 may be used (e.g., as a mold) for creating waveguide patterns (e.g., on curved glass, on curved plastic, on patterned Geometric Phase (GP) (e.g., based on Liquid Crystal material), meta-lens on curved substrates, waveguide or meta-lens pattern on curved substrates at a smaller form factor (e.g., contact lens)).
In some embodiments, the pattern 706 is coated with a release layer to form a pattern transfer surface (e.g., for releasing, when the pattern 706 is used as a mold). For example, the release layer coating comprises SiO2, Au, Al, or Al2O3 with or without Fluorinated Siliane treatment (e.g., FOTS).
In some embodiments, the process described with respect to
In some embodiments, the pattern 706 is transferred into the curved surface via etch processes, such a Reactive Ion Etching (RIE), Inductively Coupled Plasma-RIE, Ion Beam Milling, and Etching using gases such a CHF3, CF3, SF6, Cl2, O2, Ar. The curved surface 700 may comprise material such as Fused Silica (SiO2), Quartz (SiO2), Chrome coated Fused Silica, Soda Lime. The etched pattern can also be transferred into a thin film deposited over the curved surface using Physical Vapor Deposition processes (e.g., evaporation, sputter) and/or Chemical Vapor Deposition processes (e.g., plasma-enhanced CVD, Atomic layer deposition). Such films can comprise Silicon Nitride (Si3N4), Silicon Oxy-Nitride, and Silicon Dioxide (SiO2). It should be appreciated that other processes, gases, and material may be used to transfer the pattern.
In some embodiments, the micro-patterns or nano-patterns may be varied across a curved area covered by the superstrate. In some embodiments, the type of resist dispensed may be varied across the curved area covered by the substrate (e.g., to vary surface tension, to vary viscosity, to change contact angle) to optimize capillary hold force for different curvature depths (e.g., for forming the varying micro-patterns or nano-patterns).
Due to the varying volume, after the superstrate 804 is applied (e.g., ensuring proper bending and conformal coverage), a thickness across the patterning material 802 (e.g., a distance between the curved surface 800 and the superstrate 804 at a location across the patterning material) may vary. For example, as illustrated, volumes of deposition closer to an edge of the curved surface 800 being smaller than volumes of deposition closer to a center of the curved surface 800, a first thickness 806 closer to the edge of the curved surface 800 is thinner than a second thickness 808 closer to the center of the curved surface 800. As a result, pattern 810, which corresponds to the first thickness 806, is at a lower height relative to the curved surface 800, compared to pattern 812, which corresponds to the second thickness 808. The relationship between volume, thickness, and created pattern may be predicted as described with respect to equations (1) and (2) and Table 1.
For example, the different material may comprise a material with varying refractive index (e.g., a first material (e.g., patterning material 822A) having an index of 1.53 and a second material (e.g., patterning material 822B) having an index of 1.9). The first material may comprise UV curable polymers such as acrylates and vinyl esters. The second material may comprise Sulphur, aromatic molecule in the carbon chain, or a high-index nanoparticles such as TiO2 and ZrO2. More generally, in some embodiments, a patterning material disclosed herein comprises the first material, the second material, or both the first and second material.
In some embodiments, the spreading is different because nano-channel arrangements associated with patterning material 822A (e.g., nano-channel arrangements located on the curved surface where the corresponding material is deposited) and patterning material 822B are different. For example, the nano-channel arrangements associated with patterning material 822A allow the patterning material 822A to spread more, compared to the patterning material 822B.
Due to the varied spreading, after the superstrate 824 is applied, a thickness across the patterning material 822A and 822B (e.g., a distance between the curved surface 820 and the superstrate 824 at a location across the patterning material) may vary. For example, as illustrated, a first thickness 826 corresponding to the patterning material 822A is thinner than a second thickness 828 corresponding to the patterning material 822B. As a result, pattern 830, which corresponds to the patterning material 822A, is at a lower height relative to the curved surface 800, compared to pattern 832, which corresponds to the patterning material 822B. The relationship between volume, thickness, and created pattern may be predicted as described with respect to equations (1) and (2) and Table 1.
Due to the varied deposition locations, after the superstrate 844 is applied, a thickness across the patterning material 842A and 842B (e.g., a distance between the curved surface 840 and the superstrate 844 at a location across the patterning material) may vary. For example, as illustrated, a first thickness 846 corresponding to the patterning material 842A is thinner than a second thickness 848 corresponding to the patterning material 842B.
The different thicknesses may correspond to different patterns being created by the superstrate 844. For example, the first thickness 846 may be a thickness for applying a sufficient force (e.g., based on equations (1) and (2) and Table 1) for creating pattern 850, and the second thickness 848 may be a thickness for applying a sufficient force for creating pattern 852. As a result, sufficient forces, corresponding to patterns to be created, are allowed to be applied based on the thicknesses. The force for creating pattern 850 may be greater than the force for creating pattern 852, and thus a thinner thickness is needed to apply a larger capillary force for creating the pattern 850. The relationship between volume, thickness, and created pattern may be predicted as described with respect to equations (1) and (2) and Table 1.
In some embodiments, the pattern created in
In some instances, to provide a necessary impetus for the superstrate (e.g., a flexible CRT) to bend and conform, the ability to initiate surface contact towards the curved surface with resist may be needed.
In some embodiments, a concave/convex push roller 900A or 900B (e.g., up-down, left-right) is used to provide the force for positioning the superstrate (e.g., by rolling the roller on top of the superstrate 910 to cause the superstrate 910 to contact the patterning material (beneath the superstrate) for forming the micro-patterns or nano-patterns described herein). In some embodiments, a compliant z-head mechanism 902A or 902B is used to provide the force for positioning the superstrate (e.g., with up-down movement to cause the superstrate 910 to contact the patterning material (beneath the superstrate) for forming the micro-patterns or nano-patterns described herein).
In some embodiments, a non-contact method such as using a pressurized inert gas, air, or creation of pressure difference (e.g., by creating lower pressure sections) may be used for creating a force for positioning a superstrate (e.g., flexible CRT) and forming specific micro-patterns or nano-patterns.
For example, using a disclosed process for contacting the superstrate with the patterning material, imprinting on a NBK-7 lens (n=1.53) with −1D power using a flexible CRT (e.g., a co-extruded PC or PET web/roll at 50-550 μm thickness) may be achieved over a curved surface having 50 mm in diameter. In this example, the flexible CRT may have a depth of curvature in the center of 600 μm with respect to an edge. When pushed against the curve surface using a disclosed process, the CRT advantageously conforms to and held the shape of the curvature. In some examples, the superstrate may have an additional benefit of planarizing any scratch or void (e.g., haze) on the curved surface.
In some embodiments, the material 1106 is molded between the first mold 1100A and the second mold 1100B. For example, the curable waveguide resin is molded between the two molds. The curvature of the two molds and the patterns 1102 and 1104 are determined based on a desired radius of curvature of an end product created by the molds 1100A and 1100B. For example, the desired radius of curvature is a desired waveguide radius of curvature, and the waveguide has a pattern corresponding to patterns 1102 and 1104. The curvature of the two molds may be created using a process described with respect to
In some embodiments, the first optical pattern 1110 and/or the second optical pattern in 1112 comprises one or a combination of the following: input coupling element to diffract incoming light from source into the substrate in total internal reflection; pupil expanding element, which helps direct and spread light towards diffractive elements near a user's eye; exit pupil or out-coupling element, which extracts light outwards from the user to generate a virtual image; or anti-reflective pattern for increase transmissivity.
In some embodiments, the end product 1108 is a refractive lens having antireflective features. As an example, a lens curvature may have a 20 mm radius aperture +/−1.25 D lens power with a 425 mm radius of curvature. The height or depth of the curvature is about 450 μm for a 1.53 index lens material, about 400 μm for a 1.65 index lens material, and above 350 μm for a 1.75 index lens material.
In some embodiments, the processes described with respect to
In some embodiments, a system (e.g., a MR system described herein) includes a wearable head device (e.g., a MR device, a wearable head device described herein) comprising a display. In some embodiments, the display includes an optical stack that comprises an optical feature (e.g., end product 1108 including pattern 1110 and/or pattern 1112), and the optical feature is formed using a process or method described with respect to
In some embodiments, the method 1200 includes depositing a patterning material on a curved surface (step 1202). For example, as described with respect to
In some embodiments, the curved surface comprises one or more nano-channel arrangements. For example, as described with respect to
In some embodiments, each of the one or more nano-channel arrangements is arranged at an angle of zero degree, twelve degrees, or twenty-two degrees relative to an edge of the curved surface. For example, as described with respect to
In some embodiments, the method 1200 includes positioning a superstrate over the patterning material (step 1204). In some embodiments, the superstrate comprises a template for creating a pattern. For example, as described with respect to
In some embodiments, the superstrate comprises a flexible coated resist template. For example, as described with respect to
In some embodiments, positioning the superstrate over the patterning material comprises applying a force on the superstrate to bend the superstrate toward the curved surface. For example, as described with respect to
In some embodiments, the force on the superstrate is applied using a roller or a mechanism. For example, as described with respect to
In some embodiments, the force on the superstrate maintains a distance between the superstrate and the curved surface, and the distance corresponds to the applied force. For example, as described with respect to
In some embodiments, the method 1200 includes applying, using the patterning material, a force between the curved surface and the superstrate (step 1206). In some embodiments, the force comprises a capillary force. For example, as described with respect to
In some embodiments, the force is based on a thickness of the patterning material, a contact angle of patterning material, or both. For example, as described with respect to
In some embodiments, the method 1200 includes ceasing applying the force on the superstrate after the force between the curved surface and the superstrate is applied. For example, as described with respect to
In some embodiments, the method 1200 includes curing the patterning material (step 1208). In some embodiments, the cured patterning material comprises the pattern. For example, as described with respect to
In some embodiments, the method 1200 includes removing the superstrate (step 1210). For example, as described with respect to
In some embodiments, the method 1200 includes forming an optical structure using the pattern. For example, as described with respect to
In some embodiments, the optical structure comprises a curved waveguide. For example, as described with respect to
In some embodiments, the optical structure comprises a lens having an antireflective feature corresponding to the pattern. For example, as described with respect to
In some embodiments, the method 1200 includes coating the pattern with a release layer. For example, as described with respect to
In some embodiments, the first patterning material has a first volume, and the first patterning material is deposited at a first location with respect to the curved surface. In some embodiments, the method 1200 includes depositing a second patterning material having a second volume at a second location with respect to the curved surface. In some embodiments, a first thickness of the first patterning material at the first location corresponds to a thickness of the first volume, and a second thickness of the second patterning material at the second location corresponds to a thickness of the second volume. For example, as described with respect to
In some embodiments, the first patterning material comprises a first material, and the first patterning material is deposited at a first location with respect to the curved surface. In some embodiments, the method 1200 includes depositing a second patterning material comprising a second material at a second location with respect to the curved surface. In some embodiments, a first thickness of the first patterning material at the first location corresponds to a property of the first material, and a second thickness of the second patterning material at the second location corresponds to a property of the second material. For example, as described with respect to
In some embodiments, the first patterning material is deposited at a plurality of first locations of the curved surface, the first locations separated by first intervals, and the cured patterning material further comprises a second pattern. In some embodiments, the method 1200 includes depositing a second patterning material at a plurality of second locations of the curved surface, the second locations separated by second intervals. In some embodiments, the first intervals correspond to a first thickness for applying the first force for creating the first pattern, and the second intervals correspond to a second thickness for applying a second force for creating the second pattern. For example, as described with respect to
According to some embodiments, a method comprises: depositing a patterning material on a curved surface; positioning a superstrate over the patterning material, the superstrate comprising a template for creating a pattern; applying, using the patterning material, a force between the curved surface and the superstrate; curing the patterning material, wherein the cured patterning material comprises the pattern; and removing the superstrate.
According to some embodiments, the method further comprises forming an optical structure using the pattern.
According to some embodiments, the optical structure is formed by using the pattern to mold a curable resin.
According to some embodiments, the optical structure comprises a curved waveguide.
According to some embodiments, the pattern corresponds to a focal point of the curved waveguide.
According to some embodiments, the optical structure comprises a lens having an antireflective feature corresponding to the pattern.
According to some embodiments, the curved surface comprises one or more nano-channel arrangements.
According to some embodiments, each of the one or more nano-channel arrangements is arranged at an angle of zero degree, twelve degrees, or twenty-two degrees relative to an edge of the curved surface.
According to some embodiments, the method further comprises spreading the patterning material over the nano-channel arrangements.
According to some embodiments, the force comprises a capillary force.
According to some embodiments, the force is based on a thickness of the patterning material, a contact angle of patterning material, or both.
According to some embodiments, the force maintains a position of the applied superstrate relative to the curved surface.
According to some embodiments, depositing the patterning material on the curved surface comprises inkjetting the patterning material.
According to some embodiments, positioning the superstrate over the patterning material comprises applying a force on the superstrate to bend the superstrate toward the curved surface.
According to some embodiments, the force on the superstrate is applied using a roller or a mechanism.
According to some embodiments, the force on the superstrate maintains a distance between the superstrate and the curved surface, and the distance corresponds to the applied force.
According to some embodiments, the method further comprises ceasing applying the force on the superstrate after the force between the curved surface and the superstrate is applied using the patterning material.
According to some embodiments, the superstrate comprises a flexible coated resist template.
According to some embodiments, the superstrate comprises PC, polyethylene terephthalate, or both.
According to some embodiments, the superstrate has a thickness of 50-550 μm.
According to some embodiments, the superstrate has an elastic modulus less than 10 GPa.
According to some embodiments, the method further comprises coating the pattern with a release layer.
According to some embodiments, the method further comprises bonding the patterning material with the curved surface via a covalent bond.
According to some embodiments, the first patterning material has a first volume, and the first patterning material is deposited at a first location with respect to the curved surface.
The method further comprises depositing a second patterning material having a second volume at a second location with respect to the curved surface. A first thickness of the first patterning material at the first location corresponds to a thickness of the first volume, and a second thickness of the second patterning material at the second location corresponds to a thickness of the second volume.
According to some embodiments, the first patterning material comprises a first material, and the first patterning material is deposited at a first location with respect to the curved surface. The method further comprises depositing a second patterning material comprising a second material at a second location with respect to the curved surface. A first thickness of the first patterning material at the first location corresponds to a property of the first material, and a second thickness of the second patterning material at the second location corresponds to a property of the second material.
According to some embodiments, the first patterning material is deposited at a plurality of first locations of the curved surface, the first locations separated by first intervals, and the cured patterning material further comprises a second pattern. The method further comprises depositing a second patterning material at a plurality of second locations of the curved surface, the second locations separated by second intervals. The first intervals correspond to a first thickness for applying the first force for creating the first pattern, and the second intervals correspond to a second thickness for applying a second force for creating the second pattern.
According to some embodiments, the method further comprises transferring, via etching, the pattern onto the curved surface.
According to some embodiments, an optical stack comprises an optical feature. The optical feature is formed using any of the above methods.
According to some embodiments, a system comprises: a wearable head device comprising a display. The display comprises an optical stack comprising an optical feature, and the optical feature is formed using any of the above methods; and one or more processors configured to execute a method comprising: presenting, on the display, content associated with a mixed reality environment, wherein the content is presented based on the optical feature.
Although the disclosed examples have been fully described with reference to the accompanying drawings, it is to be noted that various changes and modifications will become apparent to those skilled in the art. For example, elements of one or more implementations may be combined, deleted, modified, or supplemented to form further implementations. Such changes and modifications are to be understood as being included within the scope of the disclosed examples as defined by the appended claims.
This application claims priority to U.S. Provisional Application No. 63/182,522, filed on Apr. 30, 2021, the contents of which are both incorporated by reference herein in its entirety.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2022/071986 | 4/28/2022 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 63182522 | Apr 2021 | US |
