Imprint lithography processes and methods on curved surfaces

Abstract

Methods for creating a pattern on a curved surface and an optical structure (e.g., a curved waveguide, a lens with anti-reflective features, an optical structure of a wearable head device) are disclosed. In some embodiments, the method includes: depositing a patterning material on a curved surface; positioning a superstrate on the patterning material, the superstrate including a template for creating a pattern; applying a force between the curved surface and the superstrate using the patterning material; curing the patterning material, wherein the cured patterning material includes the pattern; and removing the superstrate. In some embodiments, the method includes: using the pattern to form an optical structure.

Description

[0001] Cross-references to related applications

[0002] This application claims the benefit of U.S. Provisional Application No. 63 / 182,522, filed April 30, 2021, the contents of which are incorporated herein by reference in their entirety. Technical Field

[0003] This disclosure generally relates to curved surfaces, such as imprint lithography on the surface of a curved waveguide. Background Technology

[0004] It may be desirable to pattern micro- or nano-patterns on curved surfaces. For example, fabricating curved waveguides for mixed reality (MR) devices may include patterning micro- or nano-patterns on curved surfaces (e.g., curved waveguide substrates), and the patterning can improve the presentation of MR content on the device. The process of patterning micro- or nano-patterns on curved surfaces can be complex because conventional patterning processes using rigid supersubstrates (e.g., templates) (e.g., substrate thickness control (e.g., photolithography), total thickness variation (TTV)) may not reliably fabricate these patterns on curved surfaces. For example, conventional processes may lack the ability to control the volume of curable material distributed on such surfaces (e.g., on a substrate, under a superstrate).

[0005] To reliably and efficiently fabricate these patterns on curved surfaces, an understanding of the patterning mechanisms may be required. For example, some process parameters may be inflexible, while others may be flexible. Identifying adjustable parameters that can be optimized and allowing these parameters to be adjusted can enable the efficient fabrication of these patterns on curved surfaces. Summary of the Invention

[0006] Methods for creating patterns on curved surfaces and optical structures (e.g., curved waveguides, lenses with anti-reflective features, optical structures of wearable head devices) are disclosed. In some embodiments, a method includes: depositing a patterned material on a curved surface; positioning a cover plate on the patterned material, the cover plate including a template for creating the pattern; applying a force between the curved surface and the cover plate using the patterned material; curing the patterned material, wherein the cured patterned material includes the pattern; and removing the cover plate.

[0007] In some embodiments, the method further includes forming an optical structure using the pattern.

[0008] In some embodiments, the optical structure is formed using the pattern-molded curable resin.

[0009] In some embodiments, the optical structure includes a bent waveguide.

[0010] In some embodiments, the pattern corresponds to the focal point of the curved waveguide.

[0011] In some embodiments, the optical structure includes a lens having anti-reflective features corresponding to the pattern.

[0012] In some embodiments, the curved surface includes one or more nanochannel arrangements.

[0013] In some embodiments, each of the one or more nanochannel arrangements is arranged at an angle of zero, twelve, or twenty-two degrees relative to the edge of the curved surface.

[0014] In some embodiments, the method further includes: diffusing the patterned material onto the nanochannel arrangement.

[0015] In some embodiments, the force includes capillary force.

[0016] In some embodiments, the force is based on the thickness of the patterned material, the contact angle of the patterned material, or both.

[0017] In some embodiments, the force maintains the position of the applied cover plate relative to the curved surface.

[0018] In some embodiments, depositing the patterned material on the curved surface includes inkjet printing the patterned material.

[0019] In some embodiments, positioning the cover plate on the patterned material includes applying a force to the cover plate to bend the cover plate toward the curved surface.

[0020] In some embodiments, a force is applied to the cover plate using a roller or mechanism.

[0021] In some embodiments, the force on the cover plate maintains the distance between the cover plate and the curved surface, and the distance corresponds to the applied force.

[0022] In some embodiments, the method further includes: after applying a force between the curved surface and the cover plate using the patterned material, stopping the application of the force on the cover plate.

[0023] In some embodiments, the cover plate includes a flexibly coated resist template.

[0024] In some embodiments, the cladding includes PC, polyethylene terephthalate, or both.

[0025] In some embodiments, the cover plate has a thickness of 50-550 μm.

[0026] In some embodiments, the cladding has an elastic modulus of less than 10 GPa.

[0027] In some embodiments, the method further includes coating the pattern with a release layer.

[0028] In some embodiments, the method further includes bonding the patterned material to the curved surface via covalent bonds.

[0029] In some embodiments, the first patterned material has a first volume, and the first patterned material is deposited at a first location relative to the curved surface. The method further includes depositing a second patterned material having a second volume at a second location relative to the curved surface. A first thickness of the first patterned material at the first location corresponds to the thickness of the first volume, and a second thickness of the second patterned material at the second location corresponds to the thickness of the second volume.

[0030] In some embodiments, the first patterned material comprises a first material, and the first patterned material is deposited at a first location relative to the curved surface. The method further comprises depositing a second patterned material comprising a second material at a second location relative to the curved surface. A first thickness of the first patterned material at the first location corresponds to the properties of the first material, and a second thickness of the second patterned material at the second location corresponds to the properties of the second material.

[0031] In some embodiments, the first patterned material is deposited at a plurality of first locations on the curved surface, the first locations being separated by a first interval, and the cured patterned material further includes a second pattern. The method further includes depositing a second patterned material at a plurality of second locations on the curved surface, the second locations being separated by a second interval. The first interval corresponds to a first thickness for applying a first force to create the first pattern, and the second interval corresponds to a second thickness for applying a second force to create the second pattern.

[0032] In some embodiments, the method further includes transferring the pattern onto the curved surface via the etching.

[0033] In some embodiments, an optical stack includes optical features. The optical features are formed using any of the methods described above.

[0034] In some embodiments, a system includes: a wearable head device including a display. The display includes an optical stack including optical features, and the optical features are formed using any of the methods described above; and one or more processors configured to perform a method including the step of: presenting content associated with a mixed reality environment on the display, wherein the content is presented based on the optical features. Attached Figure Description

[0035] Figures 1A to 1C An exemplary environment according to one or more embodiments of this disclosure is shown.

[0036] Figures 2A to 2D Components of an exemplary mixed reality system according to embodiments of the present disclosure are shown.

[0037] Figure 3A An exemplary mixed reality handheld controller according to an embodiment of the present disclosure is shown.

[0038] Figure 3B An exemplary auxiliary unit according to an embodiment of the present disclosure is shown.

[0039] Figure 4 An exemplary functional block diagram of an exemplary mixed reality system according to an embodiment of the present disclosure is shown.

[0040] Figures 5A to 5B An exemplary waveguide layer according to an embodiment of the present disclosure is shown.

[0041] Figures 6A to 6D An exemplary nanochannel arrangement according to an embodiment of the present disclosure is shown.

[0042] Figures 7A to 7F The fabrication of an exemplary pattern on a curved surface according to an embodiment of the present disclosure is shown.

[0043] Figures 8A to 8C The fabrication of an exemplary pattern on a curved surface according to an embodiment of the present disclosure is shown.

[0044] Figure 9 An exemplary force transfer method for creating patterns on a curved surface is illustrated according to an embodiment of the present disclosure.

[0045] Figures 10A to 10E An exemplary application of a pattern manufactured on a curved surface according to an embodiment of the present disclosure is shown.

[0046] Figures 11A to 11D An exemplary application of a pattern manufactured on a curved surface according to an embodiment of the present disclosure is shown.

[0047] Figure 12An exemplary method for creating patterns on a curved surface according to embodiments of the present disclosure is shown. Detailed Implementation

[0048] In the following description of the examples, reference is made to the accompanying drawings, which form part of the description and illustrate specific examples that can be implemented by way of example. It should be understood that other examples may be used and structural changes may be made without departing from the scope of the disclosed examples.

[0049] Like everyone else, users of mixed reality systems exist within a real-world environment—that is, the three-dimensional portion of the “real world” that the user can perceive, and all of its contents. For example, users perceive the real world using ordinary human senses (sight, sound, touch, taste, smell) and interact with it by moving their bodies within it. A position in the real-world environment can be described as coordinates in a coordinate space; for example, coordinates may include latitude, longitude, and altitude relative to sea level; distance from a reference point in three orthogonal dimensions; or other suitable values. Similarly, vectors can describe quantities that have direction and magnitude in coordinate space.

[0050] A computing device may maintain a representation of a virtual environment, for example, in memory associated with the device. As used herein, a virtual environment is a computational representation of a three-dimensional space. A virtual environment may include a representation of any object, action, signal, parameter, coordinate, vector, or other characteristic associated with that space. In some examples, the circuitry of the computing device (e.g., a processor) may maintain and update the state of the virtual environment; that is, the processor may determine the state of the virtual environment at a first time t0 based on data associated with the virtual environment and / or input provided by the user at a second time t1. For example, if an object in the virtual environment is located at a first coordinate at time t0 and has some programmed physical parameter (e.g., mass, coefficient of friction); and input received from the user indicates that a force should be applied to the object in a direction vector; then the processor may apply laws of kinematics to determine the position of the object at time t1 using fundamental mechanics. The processor may use any suitable information known about the virtual environment and / or any suitable input to determine the state of the virtual environment at time t1. While maintaining and updating the state of the virtual environment, the processor may execute any suitable software, including software related to the creation and deletion of virtual objects in the virtual environment; software for defining the behavior of virtual objects or characters in the virtual environment (e.g., scripts); 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 processing inputs and outputs; software for implementing network operations; software for applying asset data (e.g., animation data of virtual objects moving over time); or many other possibilities.

[0051] Output devices, such as displays or speakers, can present any or all aspects of a virtual environment to a user. For example, a virtual environment can include virtual objects that can be presented to the user (which may include representations of inanimate objects; people; animals; lights, etc.). A processor can determine a view of the virtual environment (e.g., corresponding to a “camera” with a coordinate origin, a viewing axis, and a viewing frustum); and render a visual scene of the virtual environment corresponding to that view to the display. For this purpose, any suitable rendering technique can be used. In some examples, the visual scene may include some virtual objects in the virtual environment and exclude certain other virtual objects. Similarly, a virtual environment can include audio aspects that can be presented to the user as one or more audio signals. For example, virtual objects in the virtual environment can generate sounds derived from the object's location coordinates (e.g., a virtual character can speak or cause sound effects); or the virtual environment may be associated with musical cues or ambient sounds, which may or may not be associated with a specific location. The processor can determine the audio signal corresponding to the “listener” coordinates—for example, a composite of sounds in a virtual environment that is mixed and processed to simulate the audio signal that will be heard by the listener at the listener’s coordinates—and present the audio signal to the user via one or more speakers.

[0052] Because the virtual environment exists as a computational structure, users can perceive it directly without using their ordinary senses. Instead, users can perceive the virtual environment indirectly, such as through displays, speakers, haptic output devices, etc. Similarly, users can interact with the virtual environment without directly touching, manipulating, or otherwise engaging with it; however, they can provide input data to a processor that can update the virtual environment using input devices or sensors. For example, a camera sensor can provide optical data indicating that a user is attempting to move an object in the virtual environment, and the processor can use this data to make the object react accordingly in the virtual environment.

[0053] Mixed reality systems can present a mixed reality environment (MRE) to a user, combining aspects of a real and a virtual environment, for example, using a transmissive display and / or one or more speakers (which may be included, for example, in a wearable head-mounted device). In some embodiments, one or more speakers may be external to the wearable head-mounted device. As used herein, an 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, the real coordinate space and the corresponding virtual coordinate space are correlated with each other through a transformation matrix (or other suitable representation). Thus, a single coordinate (in some examples, together with the transformation matrix) can define a first position in the real environment and a second corresponding position in the virtual environment; and vice versa.

[0054] In MRE, virtual objects (e.g., in a virtual environment associated with the MRE) can correspond to real objects (e.g., in a real environment associated with the MRE). For example, if the real environment of the MRE includes a real lamppost (real object) at location coordinates, then the virtual environment of the MRE can include a virtual lamppost (virtual object) at the corresponding location coordinates. As used herein, real objects combined with their corresponding virtual objects constitute "mixed reality objects." Virtual objects do not need to perfectly match or align with their corresponding real objects. In some examples, virtual objects can be simplified versions of their corresponding real objects. For example, if the real environment includes a real lamppost, the corresponding virtual object can include a cylinder with approximately the same height and radius as the real lamppost (reflecting that the lamppost can be approximately cylindrical in shape). Simplifying virtual objects in this way allows for computational efficiency and simplifies the computations performed on such virtual objects. Furthermore, in some examples of the MRE, not all real objects in the real environment can be associated with corresponding virtual objects. Similarly, in some examples of the MRE, not all virtual objects in the virtual environment can be associated with corresponding real objects. That is, some virtual objects can exist only in the virtual environment of MRE without any real-world counterparts.

[0055] In some examples, virtual objects can possess characteristics that differ from (and sometimes even drastically differ from) their corresponding real-world counterparts. For instance, while a real-world environment in an MRE might include a green, two-armed cactus—a thorny, inanimate object—the corresponding virtual object in the MRE could possess the characteristics of a green, two-armed virtual character with human-like features and aggressive behavior. In this example, the virtual object resembles its real-world counterpart in some characteristics (color, number of arms); but differs from it in other characteristics (facial features, personality). In this way, virtual objects have the potential to represent real-world objects in a creative, abstract, exaggerated, or imaginative way; or to impart behavior to other inanimate real-world objects (e.g., human personalization). In some examples, virtual objects can be purely imaginary creations without any real-world counterpart (e.g., a virtual monster in a virtual environment, perhaps occupying a location corresponding to an empty space in a real environment).

[0056] In some examples, virtual objects can possess characteristics similar to their corresponding real-world counterparts. For instance, virtual characters can be presented as lifelike figures in virtual or mixed reality environments to provide users with an immersive mixed reality experience. By giving virtual characters lifelike characteristics, users can feel as if they are interacting with a real person. In this case, actions such as the virtual character's muscle movements and gaze are expected to appear natural. For example, the virtual character's movements should resemble their corresponding real-world counterpart (e.g., a virtual person should walk or move their arms like a real person). As another example, the virtual person's gestures and positioning should appear natural, and the virtual person should be able to initiate interactions with the user (e.g., a virtual person can guide the user through a collaborative experience). This paper will describe the presentation of virtual characters with lifelike characteristics in more detail.

[0057] Compared to Virtual Reality (VR) systems, which present a virtual environment to the user while blurring the real environment, Mixed Reality (MR) systems, which present a virtual environment, offer the advantage of maintaining the perceptibility of the real environment while the virtual environment is presented. Therefore, users of MR systems can experience and interact with the corresponding virtual environment using visual and audio cues associated with the real environment. For example, while a VR user might struggle to perceive or interact with virtual objects displayed in the virtual environment—as described herein, the user doesn't directly perceive or interact with the virtual environment—a MR user can discover their interaction with virtual objects more intuitively and naturally by seeing, hearing, and touching corresponding real objects in their own real environment. This level of interactivity can enhance the user's sense of immersion, connection, and engagement with the virtual environment. Similarly, by simultaneously presenting the real and virtual environments, MR systems can reduce the negative psychological sensations (e.g., cognitive dissonance) and negative physical sensations (e.g., motion sickness) associated with VR systems. Furthermore, MR systems offer numerous possibilities for applications that can enhance or alter our experiences of the real world.

[0058] Figure 1A An exemplary real-world environment 100 in which user 110 uses a mixed reality system 112 is illustrated. The mixed reality system 112 may include a display (e.g., a transmissive display), one or more speakers, and one or more sensors (e.g., cameras), such as those described herein. The illustrated real-world environment 100 includes a rectangular room 104A in which user 110 stands; and real-world objects 122A (lamp), 124A (table), 126A (sofa), and 128A (painting). Room 104A can be spatially described using positional coordinates (e.g., coordinate system 108); the location of the real-world environment 100 can be described about the origin of the positional coordinates (e.g., point 106). Figure 1AAs shown, an environment / world coordinate system 108 (including x-axis 108X, y-axis 108Y, and z-axis 108Z) with its origin at point 106 (world coordinates) can define the coordinate space for the real environment 100. In some embodiments, the origin 106 of the environment / world coordinate system 108 can correspond to the location where the mixed reality environment 112 is powered. In some embodiments, the origin 106 of the environment / world coordinate system 108 can be reset during operation. In some examples, user 110 can be considered a real object in the real environment 100; similarly, body parts of user 110 (e.g., hands, feet) can be considered real objects in the real environment 100. In some examples, a user / listener / head coordinate system 114 (including x-axis 114X, y-axis 114Y, and z-axis 114Z) with its origin at point 115 (e.g., user / listener / head coordinates) can define the coordinate space of the user / listener / head where the mixed reality system 112 is located. The origin 115 of the user / listener / head coordinate system 114 can be defined relative to one or more components of the mixed reality system 112. For example, the origin 115 of the user / listener / head coordinate system 114 can be defined relative to the display of the mixed reality system 112, such as during the initial calibration of the mixed reality system 112. Matrices (which may include translation matrices and quaternion matrices or other rotation matrices) or other suitable representations can characterize the transformation between the user / listener / head coordinate system 114 space and the environment / world coordinate system 108 space. In some embodiments, the left ear coordinates 116 and the right ear coordinates 117 can be defined relative to the origin 115 of the user / listener / head coordinate system 114. Matrices (which may include translation matrices and quaternion matrices or other rotation matrices) or other suitable representations can characterize the transformation between the left ear coordinates 116 and the right ear coordinates 117 and the user / listener / head coordinate system 114 space. User / listener / head coordinate system 114 can simplify the representation of position relative to the user's head or head-mounted device, for example, relative to environment / world coordinate system 108. The transformation between user coordinate system 114 and environment coordinate system 108 can be determined and updated in real time using simultaneous localization and mapping (SLAM), visual odometry, or other techniques.

[0059] Figure 1BAn exemplary virtual environment 130 corresponding to the real environment 100 is shown. The virtual environment 130 shown includes a virtual rectangular room 104B corresponding to the real rectangular room 104A; a virtual object 122B corresponding to the real object 122A; a virtual object 124B corresponding to the real object 124A; and a virtual object 126B corresponding to the real object 126A. Metadata associated with virtual objects 122B, 124B, and 126B may include information derived from the corresponding real objects 122A, 124A, and 126A. The virtual environment 130 additionally includes a virtual character 132, which may not correspond to any real object in the real environment 100. A real object 128A in the real environment 100 may not correspond to any virtual object in the virtual environment 130. A persistent coordinate system 133 (including x-axis 133X, y-axis 133Y, and z-axis 133Z) with its origin at point 134 (persistent coordinates) can define the coordinate space used for the virtual content. The origin 134 of the persistent coordinate system 133 can be defined relative to / about one or more real objects, such as real object 126A. Matrices (which may include translation matrices and quaternion matrices or other rotation matrices) or other suitable representations can characterize the transformation between the space of the persistent coordinate system 133 and the environment / world coordinate system 108. In some embodiments, each of the virtual objects 122B, 124B, 126B, and 132 can have its own persistent coordinate point relative to the origin 134 of the persistent coordinate system 133. In some embodiments, multiple persistent coordinate systems can exist, and each of the virtual objects 122B, 124B, 126B, and 132 can have its own persistent coordinate point relative to one or more persistent coordinate systems.

[0060] Persistent coordinate data can be coordinate data that persists relative to the physical environment. Persistent coordinate data can be used by MR systems (e.g., MR systems 112, 200) to place persistent virtual content, which can be independent of the movement of the display showing the virtual object. For example, a 2D screen can display a virtual object relative to a certain position on the screen. As the 2D screen moves, the virtual content can move with the screen. In some embodiments, persistent virtual content can be displayed in a corner of a room. An MR user might look towards the corner, see the virtual content, look away from the corner (the virtual content may no longer be visible because it may have moved from within the user's field of vision to outside due to head movement), and then look back at the virtual content in the corner (similar to the behavior of a real object).

[0061] In some embodiments, persistent coordinate data (e.g., a persistent coordinate system and / or a persistent coordinate frame) may include an origin and three axes. For example, a persistent coordinate system may be assigned to the center of a room by the MR system. In some embodiments, a user can move around the room, leave 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, transformations to persistent coordinate data may be used to display virtual objects, which may enable the display of persistent virtual content. In some embodiments, the MR system may use simultaneous localization and map creation to generate persistent coordinate data (e.g., the MR system may assign persistent coordinate systems to points in space). In some embodiments, the MR system may map the environment by generating persistent coordinate data at fixed intervals (e.g., the MR system may assign persistent coordinate systems in a grid, where the persistent coordinate systems may be at least five feet from another persistent coordinate system).

[0062] In some embodiments, persistent coordinate data may be generated by the MR system and transmitted to a remote server. In some embodiments, the remote server may be configured to receive persistent coordinate data. In some embodiments, the remote server may be configured to synchronize persistent coordinate data from multiple observation instances. For example, multiple MR systems may map the same room using persistent coordinate data and transmit that data to a remote server. In some embodiments, the remote server may use the observation data to generate canonical persistent coordinate data, which may be based on one or more observations. In some embodiments, canonical persistent coordinate data may be more accurate and / or more 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, an MR system may use image recognition and / or location data to identify that it is located in a room with corresponding canonical persistent coordinate data (e.g., because other MR systems have previously mapped the room). In some embodiments, an MR system may receive canonical persistent coordinate data corresponding to its location from a remote server.

[0063] about Figure 1A and Figure 1BThe environment / world coordinate system 108 defines a shared coordinate space for both the real environment 100 and the virtual environment 130. In the example shown, the coordinate space has its origin at point 106. Furthermore, the coordinate space is defined by the same three orthogonal axes (108X, 108Y, 108Z). Therefore, a first position in the real environment 100 and a second corresponding position in the virtual environment 130 can be described relative to the same coordinate space. This simplifies the identification and display of corresponding positions in the real and virtual environments, as the same coordinates can be used to identify both positions. However, in some examples, the corresponding real and virtual environments do not need to use a shared coordinate space. For example, in some examples (not shown), matrices (which may include translation matrices and quaternion matrices or other rotation matrices) or other suitable representations can characterize the transformation between the real environment coordinate space and the virtual environment coordinate space.

[0064] Figure 1C An exemplary MRE 150 is shown that simultaneously presents aspects of a real environment 100 and a virtual environment 130 to a user via a mixed reality system 112. In the illustrated example, the MRE 150 simultaneously presents to the user 110 real objects 122A, 124A, 126A, and 128A from the real environment 100 (e.g., transmissive portions of the display of the mixed reality system 112); and virtual objects 122B, 124B, 126B, and 132 from the virtual environment 130 (e.g., active display portions of the display of the mixed reality system 112). As described herein, origin 106 serves as the origin for the coordinate space corresponding to the MRE 150, and coordinate system 108 defines the x-axis, y-axis, and z-axis for the coordinate space.

[0065] In the illustrated example, the mixed reality object comprises corresponding pairs of real and virtual objects (e.g., 122A / 122B, 124A / 124B, 126A / 126B) occupying corresponding positions in coordinate space 108. In some examples, both the real and virtual objects may be simultaneously visible to the user 110. This may be desirable in instances where the virtual object presents information designed to enhance the view of the corresponding real object (such as in a museum application where the virtual object presents a missing piece of an ancient damaged sculpture). In some examples, the virtual object (122B, 124B, and / or 126B) may be displayed (e.g., via active pixelation occlusion using a pixelation occlusion shutter) to occlude the corresponding real object (122A, 124A, and / or 126A). This may be desirable in 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).

[0066] In some examples, real-world objects (e.g., 122A, 124A, 126A) can be associated with virtual content or assistant data that may not necessarily constitute virtual objects. Virtual content or assistant data can facilitate the processing or disposal of virtual objects in a mixed reality environment. For example, such virtual content may include a two-dimensional representation of: the corresponding real-world object; a custom asset type associated with the corresponding real-world object; or statistical data associated with the corresponding real-world object. This information enables or facilitates computations involving real-world objects without incurring unnecessary computational overhead.

[0067] In some examples, the presentation described herein may also include audio aspects. For example, in MRE 150, a virtual character 132 may be associated with one or more audio signals, such as footsteps generated when the character walks around MRE 150. As further described herein, the processor of Mixed Reality System 112 may calculate a composite audio signal corresponding to the mixing and processing 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.

[0068] Example mixed reality system 112 may include a wearable head-mounted device (e.g., a wearable augmented reality or mixed reality head-mounted device) comprising: a display (which may include left and right transmissive displays, which may be near-eye displays, and associated components for coupling light from the display 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 side arm of the head-mounted device); an orthogonal coil electromagnetic receiver (e.g., mounted to a left support); left and right cameras (e.g., depth (time-of-flight) cameras) oriented away from the user; and left and right eye cameras oriented towards the user (e.g., for detecting the user's eye movements). However, mixed reality system 112 may incorporate any suitable display technology and any suitable sensors (e.g., optical, infrared, acoustic, LiDAR, EOG, GPS, magnetic). Additionally, the mixed reality system 112 may include network features (e.g., Wi-Fi capability, mobile network capability (e.g., 4G, 5G)) to communicate with other devices and systems (including neural networks (e.g., in the cloud) for data processing and training data associated with the presentation of elements (e.g., virtual character 132) in the MRE 150) and other mixed reality systems). The mixed reality system 112 may also include a battery (which may be housed in an assistive unit, such as a belt bag designed to be worn around the user's waist), a processor, and memory. The wearable head-mounted device of the 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-mounted device relative to the user's environment. In some examples, the tracking components may provide input to a processor performing Simultaneous Localization and Mapping (SLAM) and / or visual odometry. In some examples, the mixed reality system 112 may also include a handheld controller 300 and / or an assistive unit 320, which may be a wearable belt bag, as further described herein.

[0069] In some embodiments, the animation apparatus is used to present a virtual character 132 in the MRE 150. Although the animation apparatus is described in relation to the virtual character 132, it should be understood that the animation apparatus may be associated with other characters in the MRE 150 (e.g., human characters, animal characters, abstract characters). The movement of the animation apparatus will be described in more detail herein.

[0070] Figure 2A-2D Components of an exemplary mixed reality system 200 (which may correspond to mixed reality system 112) that can be used to present an MRE (which may correspond to MRE 150) or other virtual environment to a user are shown. Figure 2A A perspective view of a wearable head-mounted device 2102 included in an example mixed reality system 200 is shown. Figure 2BA top view of a wearable head device 2102 worn on a user's head 2202 is shown. Figure 2C A front view of the wearable head device 2102 is shown.

[0071] Figure 2D An edge view of an example eyepiece 2110 of a wearable head device 2102 is shown. Figure 2A-2C As shown, the example wearable head device 2102 includes an exemplary left eyepiece (e.g., a left transparent waveguide eyepiece) 2108 and an exemplary right eyepiece (e.g., a right transparent waveguide eyepiece) 2110. Each eyepiece 2108 and 2110 may include: a transmission element through which the real environment can be visible; and a display element for presenting a display superimposed on the real environment (e.g., via image-modulated light). In some examples, such display elements may include surface diffraction optics for controlling the flow of image-modulated light. For example, the left eyepiece 2108 may include a left-coupled-in grating set 2112, a left orthogonal pupil expansion (OPE) grating set 2120, and a left-exit (output) pupil expansion (EPE) grating set 2122. Similarly, the right eyepiece 2110 may include a right-coupled-in grating set 2118, a right OPE grating set 2114, and a right EPE grating set 2116. Image-modulated light can be delivered to the user's eye via coupling gratings 2112 and 2118, OPEs 2114 and 2120, and EPEs 2116 and 2122. Each coupling grating set 2112, 2118 can be configured to deflect light toward its corresponding OPE grating set 2120, 2114. Each OPE grating set 2120, 2114 can be designed to deflect light downwards in an incremental manner toward its associated EPEs 2122, 2116, thereby horizontally expanding the resulting exit pupil. Each EPE 2122, 2116 can be configured to progressively redirect at least a portion of the light received from its corresponding OPE grating set 2120, 2114 outwards to a user eyebox location (not shown) defined behind eyepieces 2108, 2110, thereby vertically expanding the exit pupil formed at the eyebox. Alternatively, instead of coupling grating sets 2112 and 2118, OPE grating sets 2114 and 2120, and EPE grating sets 2116 and 2122, eyepieces 2108 and 2110 may include other arrangements of gratings and / or refractive and reflective features for controlling the coupling of image-modulated light to the user's eye.

[0072] In some examples, the wearable head device 2102 may include a left support arm 2130 and a right support arm 2132, wherein the left support arm 2130 includes a left speaker 2134 and the right support arm 2132 includes a right speaker 2136. An orthogonal coil electromagnetic receiver 2138 may be positioned in the left support arm or at another suitable location within the wearable head unit 2102. An inertial measurement unit (IMU) 2140 may be positioned in the right support arm 2132 or at another suitable location within the wearable head device 2102. The wearable head device 2102 may also include a left depth (e.g., time-of-flight) camera 2142 and a right depth camera 2144. The depth cameras 2142 and 2144 may be suitably oriented in different directions to cover a wider field of view together.

[0073] exist Figure 2A-2D In the example shown, the left image modulation light source 2124 can be optically coupled to the left eyepiece 2108 via the left coupling grating set 2112, and the right image modulation light source 2126 can be optically coupled to the right eyepiece 2110 via the right coupling grating set 2118. The image modulation light sources 2124, 2126 may include, for example, fiber optic scanners; projectors including electro-optic modulators, such as digital light processing (DLP) chips or liquid crystal on silicon (LCoS) modulators; or emitting displays, such as micro light-emitting diode (μLED) or micro organic light-emitting diode (μOLED) panels, which are coupled to the coupling grating sets 2112, 2118 using one or more lenses on each side. The coupling grating sets 2112, 2118 can deflect light from the image modulation light sources 2124, 2126 to an angle greater than the critical angle for total internal reflection (TIR) ​​for the eyepieces 2108, 2110. OPE grating sets 2114 and 2120 incrementally deflect light propagating through TIR toward EPE grating sets 2116 and 2122. EPE grating sets 2116 and 2122 incrementally couple light toward the user's face, including the pupils of the user's eyes.

[0074] In some examples, such as Figure 2DAs shown, each of the left eyepiece 2108 and the right eyepiece 2110 includes multiple waveguides 2402. For example, each eyepiece 2108, 2110 may include multiple individual waveguides, each dedicated to a corresponding color channel (e.g., red, blue, and green). In some examples, each eyepiece 2108, 2110 may include multiple sets of such waveguides, wherein each set is configured to impart a different wavefront curvature to the emitted light. The wavefront curvature may be convex relative to the user's eye, for example, to present a virtual object positioned at a distance in front of the user (e.g., by a distance corresponding to the reciprocal of the wavefront curvature). In some examples, the EPE grating sets 2116, 2122 may include curved grating recesses to achieve a convex wavefront curvature by varying the Poynting vector of the emitted light across each EPE.

[0075] In some examples, to create a perception that the displayed content is three-dimensional, stereoscopically accommodated left and right eye images can be presented to the user via image-forming light modulators 2124, 2126 and eyepieces 2108, 2110. The perceptual realism of the presented three-dimensional virtual objects can be enhanced by selecting waveguides (and therefore corresponding wavefront curvatures) so that the virtual objects are displayed at distances approximately indicated by the stereoscopic left and right images. This technique can also reduce motion sickness experienced by some users, which can be caused by the discrepancy between the depth perception cues provided by the stereoscopic left and right eye images and the autoacoustic function of the human eye (e.g., object distance-related focus).

[0076] Figure 2D An edge-facing view is shown from the top of the right eyepiece 2110 of the example wearable head device 2102. (See image.) Figure 2D As shown, the multiple waveguides 2402 may include a first subset 2404 having three waveguides and a second subset 2406 having three waveguides. The two subsets 2404 and 2406 of the waveguides can be distinguished by different EPE gratings characterized by different grating line curvatures to impart different wavefront curvatures to the outgoing light. Within each of the waveguide subsets 2404 and 2406, each waveguide can be used to couple a different spectral channel (e.g., one of the red, green, and blue spectral channels) to the user's right eye 2206. Although not shown in Figure 2D As shown, however, the structure of the left eyepiece 2108 can be mirrored with the structure of the right eyepiece 2110.

[0077] Figure 3AAn exemplary handheld controller assembly 300 of a mixed reality system 200 is shown. In some examples, the handheld controller 300 includes a handle 346 and one or more buttons 350 disposed along a top surface 348. In some examples, the buttons 350 may be configured as optical tracking targets, for example, for use in conjunction with a camera or other optical sensor (which may be mounted in the head unit of the mixed reality system 200, such as wearable head device 2102) to track the six degrees of freedom (6DOF) motion of the handheld controller 300. In some examples, the handheld controller 300 includes a tracking component (e.g., an IMU or other suitable sensor) for detecting position or orientation (such as position or orientation relative to wearable head device 2102). In some examples, such a tracking component may be positioned in the handle of the handheld controller 300 and / or may be mechanically attached to the handheld controller. The handheld controller 300 may be configured to provide one or more output signals corresponding to a button press state; or one or more of the position, orientation, and / or motion (e.g., via an IMU) of the handheld controller 300. Such output signals can be used as inputs to the processor of the mixed reality system 200. Such inputs can correspond to the position, orientation, and / or movement of a handheld controller (e.g., by extension, to the position, orientation, and / or movement of a user's hand holding the controller). Such inputs can also correspond to a user pressing button 350.

[0078] Figure 3B An exemplary auxiliary unit 320 of a mixed reality system 200 is shown. The auxiliary unit 320 may include a battery that provides power to operate the system 200 and may include a processor for executing programs to operate the system 200. As shown, the example auxiliary unit 320 includes a clip 2128, such as for attaching the auxiliary unit 320 to a user's belt. Other form factors suited to the auxiliary unit 320 and will be apparent, including those not involved in mounting the unit to a user's belt. In some examples, the auxiliary unit 320 is coupled to a wearable head device 2102 via a multi-conduit cable, which may include, for example, wires and optical fibers. A wireless connection between the auxiliary unit 320 and the wearable head device 2102 may also be used.

[0079] In some examples, the mixed reality system 200 may include one or more microphones that detect sound and provide corresponding signals to the mixed reality system. In some examples, the microphone may be attached to or integrated with a wearable head device 2102 and may be configured to detect the user's voice. In some examples, the microphone may be attached to or integrated with a handheld controller 300 and / or auxiliary unit 320. Such a microphone may be configured to detect ambient sound, ambient noise, the voice of the user or a third party, or other sounds.

[0080] Figure 4 An exemplary functional block diagram is shown that can correspond to an exemplary mixed reality system, such as the mixed reality system 200 described herein (which can correspond to the mixed reality system 112 with respect to FIG1). Elements of the wearable system 400 can be used to implement the methods, operations, and features described herein. Figure 4 As shown, the example handheld controller 400B (which may correspond to the handheld controller 300 (“Totem”)) includes a totem-to-wear head-mounted device six-DOF (6DOF) totem subsystem 404A, and the example wearable head-mounted device 400A (which may correspond to the wearable head-mounted device 2102) includes a totem-to-wearable head-mounted device 6DOF subsystem 404B. In the example, the 6DOF totem subsystem 404A and 6DOF subsystem 404B cooperate to determine the six coordinates of the handheld controller 400B relative to the wearable head-mounted device 400A (e.g., offsets in three translational directions and rotations along three axes). The six degrees of freedom can be represented relative to the coordinate system of the wearable head-mounted device 400A. The three translational offsets can be represented as X, Y, and Z offsets in such a coordinate system, translation matrices, or some other representation. The rotational degrees of freedom can be represented as a sequence of yaw, pitch, and roll rotations, rotation matrices, quaternions, or some other representation. In some examples, a wearable head device 400A; one or more depth cameras 444 (and / or one or more non-depth cameras) included in the wearable head device 400A; and / or one or more optical targets (e.g., a button 450 of a handheld controller 400B as described herein, or a dedicated optical target included in the handheld controller 400B) can be used for 6DOF tracking. In some examples, as described herein, the handheld controller 400B may include a camera; and the wearable head device 400A may include an optical target for optical tracking in conjunction with the camera. In some examples, the wearable head device 400A and the handheld controller 400B each include a set of three orthogonally oriented solenoids for wirelessly transmitting and receiving three distinguishable signals. The 6DOF of the wearable head device 400A relative to the handheld controller 400B can be determined by measuring the relative amplitudes of the three distinguishable signals received in each of the coils used for receiving. In addition, the 6DOF totem subsystem 404A may include an inertial measurement unit (IMU), which is useful for providing improved accuracy and / or more timely information about the rapid movements of the handheld controller 400B.

[0081] In some embodiments, the wearable system 400 may include a microphone array 407, which may include one or more microphones disposed on a head device 400A. In some embodiments, the microphone array 407 may include four microphones. Two microphones may be positioned in front of the head device 400A, and two microphones may be positioned behind the head device 400A (e.g., one on the left rear and one on the right rear). In some embodiments, signals received by the microphone array 407 may be transmitted to a DSP 408. The DSP 408 may be configured to perform signal processing on the signals received from the microphone array 407. For example, the DSP 408 may be configured to perform noise reduction, echo cancellation, and / or beamforming on the signals received from the microphone array 407. The DSP 408 may be configured to transmit signals to a processor 416.

[0082] In some examples, transforming the 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) may become necessary, for example, to compensate for the motion of the wearable head device 400A (e.g., MR system 112) relative to coordinate system 108. For example, such a transformation may be necessary for the display of the wearable head device 400A to present virtual objects at a desired position and orientation relative to the real environment (e.g., a virtual person sitting in a real chair, facing forward, regardless of the position and orientation of the wearable head device), rather than at a fixed position and orientation on the display (e.g., at the same position in the lower right corner of the display), to maintain the illusion that the virtual objects exist in the real environment (and, for example, not appear unnaturally positioned in the real environment when the wearable head device 400A moves and rotates). In some examples, the compensation transformation between coordinate spaces can be determined by processing images from depth camera 444 using SLAM and / or visual odometry procedures to determine the transformation of the wearable head device 400A relative to coordinate system 108. exist Figure 4 In the example shown, a depth camera 444 is coupled to a SLAM / visual odometry block 406 and can provide imagery to the block 406. SLAM / visual odometry block 406 implementations may include a processor configured to process the imagery and determine the position and orientation of the user's head, which can then be used to identify transformations between the head coordinate space and another coordinate space (e.g., inertial coordinate space). Similarly, in some examples, an additional source of information about the user's head pose and position is obtained from an IMU 409. Information from the IMU 409 can be integrated with information from the SLAM / visual odometry block 406 to provide improved accuracy and / or more timely information regarding the user's head pose and position through rapid adjustment.

[0083] In some examples, depth camera 444 can feed 3D images to gesture tracker 411, which can be implemented in the processor of wearable head device 400A. Gesture tracker 411 can recognize a user's gestures, for example, by matching the 3D images received from depth camera 444 with stored patterns representing gestures. Other suitable techniques for recognizing user gestures will be apparent.

[0084] In some examples, one or more processors 416 may be configured to receive data from a 6DOF head-mounted subsystem 404B, IMU 409, SLAM / visual odometry block 406, depth camera 444, and / or gesture tracker 411 of a wearable head-mounted device. Processor 416 may also send and receive control signals from a 6DOF totem system 404A. Processor 416 may be wirelessly coupled to the 6DOF totem system 404A, as in an example where the handheld controller 400B is unrestricted. Processor 416 may also communicate with add-on components such as audio-visual content memory 418, graphics processing unit (GPU) 420, and / or digital signal processor (DSP) audio spatializer 422. DSP audio spatializer 422 may be coupled to head-related transfer function (HRTF) memory 425. GPU 420 may include a left channel output coupled to left image modulation light source 424 (e.g., for displaying content on left eyepiece 428) and a right channel output coupled to right image modulation light source 426 (e.g., for displaying content on right eyepiece 430). GPU 420 may output stereoscopic image data to image modulation light sources 424, 426, for example, as described herein with respect to... Figure 2A-2D As described. In some examples, GPU 420 can be used to render virtual elements in the ME presented on the display of wearable system 400. DSP audio spatializer 422 can output audio to left speaker 412 and / or right speaker 414. DSP audio spatializer 422 can receive input from processor 419 indicating a direction vector from the user to the virtual sound source (which can be moved by the user, e.g., via handheld controller 320). Based on the direction vector, DSP audio spatializer 422 can determine the corresponding HRTF (e.g., by accessing the HRTF or by interpolating multiple HRTFs). DSP audio spatializer 422 can then apply the determined HRTF to an audio signal, such as an audio signal corresponding to a virtual sound generated by a virtual object. This can improve the credibility and realism of the virtual sound by incorporating the user's relative position and orientation to the virtual sound in the mixed reality environment—that is, by presenting a virtual sound that matches the user's expectation of what the virtual sound will sound like (if it is a real sound in a real environment).

[0085] In some examples, such as Figure 4 As shown, one or more of the processor 416, GPU 420, DSP audio spatializer 422, HRTF memory 425, and audio / visual content memory 418 may be included in the auxiliary unit 400C (which may correspond to the auxiliary unit 320 described herein). The auxiliary unit 400C may include a battery 427 that powers its components and / or powers the wearable head device 400A or the handheld controller 400B. Including such components in an auxiliary unit that can be mounted to a user's waist can limit the size and weight of the wearable head device 400A, which in turn can reduce fatigue in the user's head and neck.

[0086] Although Figure 4 Elements corresponding to various components of the example wearable system 400 are shown, but various other suitable arrangements of these components will become apparent to those skilled in the art. For example, the head device 400A shown may include a processor and / or a battery (not shown). The included processor and / or battery may operate together with the processor and / or battery of the auxiliary unit 400C or may operate in place of the processor and / or battery of the auxiliary unit 400C. Typically, as another example, regarding Figure 4 The elements or functions presented or described in connection with the assistive unit 400C may alternatively be associated with the head device 400A or the handheld controller 400B. Furthermore, some wearable systems may completely omit the handheld controller 400B or the assistive unit 400C. Such changes and modifications will be understood to be included within the scope of the disclosed examples.

[0087] Figures 5A to 5B An exemplary waveguide layer according to an embodiment of the present disclosure is shown. Figure 5A This is a simplified cross-sectional view of the waveguide layer of the eyepiece and the light projected from the waveguide layer when the waveguide layer is characterized by a predetermined curvature, according to some embodiments. Waveguide layer 504 can be a waveguide layer created using the methods described herein. Figure 5A As shown, the surface profile characterizes waveguide layer 504. In some embodiments, the surface profile forms a curved surface, which may be defined by the radius of curvature of a spherical curvature. In some embodiments, the surface profile is aspherical, but may be approximated by a spherical shape. Due to the structure of waveguide layer 504, input surface 506 may extend through waveguide layer 504 substantially parallel to output surface 508 along its length.

[0088] When light propagates through waveguide layer 504 via total internal reflection (TIR), the output light is diffracted outside waveguide layer 504, as shown in the output ray diagram. For low curvature levels, the input surface 506 and the output surface 508 are substantially parallel to each other at the points where they pass through the waveguide layer. Therefore, when light propagates through the waveguide layer via TIR, the parallelism of the waveguide surfaces maintains the reflection angle during TIR, such that the angle between the output ray and the output surface remains constant across the waveguide layer. Since the surface normal changes slightly across the curved waveguide layer at the output surface, the output ray also changes slightly, producing... Figure 5A The divergence shown.

[0089] The divergence of the output light produced by the curvature of the output surface 508 can render the input beam 502 as if it were a point light source located at a specific distance behind the waveguide layer 504. Therefore, the surface profile or curvature of the waveguide layer 504 produces a divergence of light toward the user's or observer's eye 510, effectively rendering the light as originating from a depth plane located behind the waveguide layer relative to the eye.

[0090] The distance from which the input beam appears to originate can be correlated with the radius of curvature of waveguide layer 504. A waveguide with a higher radius of curvature can render the light source as originating from a greater distance from the waveguide layer compared to a waveguide with a lower radius of curvature. For example, as... Figure 5A As shown, waveguide layer 504 can have a radius of curvature of 0.5 m, which can be achieved, for example, by bending waveguide layer 504 by 0.4 mm across an EPE with a lateral dimension (e.g., length or width) of 40 mm. Given this example curvature of waveguide layer 504, input beam 502 appears to originate from a distance of 0.5 m from waveguide layer 504. As another example, another waveguide layer can be operated to have a radius of curvature of 0.2 m, thereby rendering the light source as appearing to the user to originate from a distance of 0.2 m from the waveguide layer. Thus, by utilizing a small amount of curvature compatible with the waveguide layer material, i.e., a fraction of a millimeter bend across a waveguide layer with a length / depth of tens of millimeters, depth-plane functionality of a two-dimensional extended waveguide (also known as a two-dimensional waveguide) can be achieved. The curvature used in embodiments of the invention can be used in a variety of commercial products, including sunglasses, vehicle windshields, etc., which may have a curvature of a few millimeters (e.g., 1-5 mm). Therefore, the small amount of curvature used in the various embodiments of the invention will not degrade the optical performance of the eyepiece; for example, examples may introduce less than 0.1 arcminutes of blur at the center field of view and less than 2 arcminutes of blur across the field of view of an eyepiece with a curvature radius of 0.5m.

[0091] Figure 5AOnly a one-dimensional cross-sectional view of the waveguide layer 504, which serves as an element of the eyepiece, is shown. However, it should be understood that the surface profile applied to the waveguide layer can also be applied in a direction orthogonal to the plane of the diagram, resulting in a two-dimensional curvature of the waveguide layer. Therefore, embodiments of the present invention provide a depth plane function to the structure of the eyepiece, particularly the waveguide layer of the eyepiece. As described herein, the depth plane function can be dual-mode or continuous, depending on the specific implementation.

[0092] Figure 5B This is a simplified cross-sectional view of the waveguide layer of the eyepiece and the light passing through it, according to some embodiments, when the waveguide layer is characterized by a predetermined curvature. (See also: Regarding...) Figure 5A As described, light projected from waveguide layer 504 allows a light source to appear towards the user's eyes in three-dimensional space. Real-world light 512, or light not projected through waveguide layer 504 for virtual reality (VR), augmented reality (AR), or mixed reality (MR) purposes, can pass through the input surface 506 and output surface 508 of waveguide layer 504 and be directed towards the user's eyes 510. A waveguide with low thickness variation (e.g., less than 1.0 μm) has negligible refractive power and allows real-world light 512 to pass through the curved surface of waveguide layer 504 with little or no interference. In some embodiments, no correction of the real-world light is required, and off-axis degradation of the real-world light caused by the surface profile of waveguide layer 504 is reduced or absent. Therefore, applying a surface profile or curvature to the waveguide layer allows virtual content to be projected from a position at a distance from the eyepiece while maintaining the integrity of the real-world light, thus allowing the real-world light to be observed by the user while the virtual content is rendered in real-time for the user in three-dimensional space.

[0093] In some embodiments, the radius of curvature of the waveguide layer (which may be a polymer waveguide layer) can dynamically vary between a first distance (e.g., 0.1 m) and infinity, which can also dynamically vary the depth plane of the eyepiece (i.e., the distance at which the projected light source appears to be rendered) between the first distance and infinity. Therefore, embodiments of the invention enable the depth plane to vary between a first distance (e.g., 0.1 m) and infinity, including depth planes commonly used in augmented or mixed reality applications. The surface profile of the waveguide layer (e.g., a flexible polymer waveguide layer) can be adjusted using various methods and mechanisms, as described in more detail herein.

[0094] In some embodiments, dynamic eyepieces are provided, wherein the depth plane of the eyepiece can vary to display virtual content at different depth planes, for example, a time-varying change as a function of time. Thus, 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 invention. In these static implementations, a fixed and predetermined surface profile or curvature characterizes the waveguide layer of the eyepiece, thereby presenting virtual content at a fixed depth plane. In contrast to some systems using external lenses, diffractive lenses, or other optical elements, embodiments using static implementations can achieve depth planes through the curvature of the waveguide layer, reducing system complexity and improving optical quality. Furthermore, some embodiments can implement a set of eyepieces, each comprising a stack of bent waveguide layers to provide two static depth planes. As an example, a first stack of three bent waveguide layers can achieve a tri-color scene at a depth plane located at 1 m using a bend of 0.2 mm width / length across the waveguide stack, and a second stack of three bent waveguide layers can achieve a second tri-color scene at a depth plane located at 0.5 m using a bend of 0.4 mm width / length across the waveguide stack. Other suitable dimensions are within the scope of the invention. In addition, binocular and monocular systems were envisioned.

[0095] In some embodiments, the disclosed waveguide is as described in U.S. Patent Publication No. US2021 / 0011305, the entire disclosure of which is incorporated herein by reference. The disclosed waveguide can enhance the presentation of images to users (e.g., mixed reality (MR) content) by improving optical properties in a cost-effective manner.

[0096] Therefore, it may be desirable to create micropatterns or nanopatterns on curved surfaces, for example, to fabricate curved waveguides for MR applications and achieve the advantages described above, or to create anti-reflective features on curved optical structures (e.g., curved lenses with anti-reflective characteristics). The process of creating micropatterns or nanopatterns on curved surfaces can be complex. Embodiments of this disclosure describe patterning mechanisms and / or parameters for efficiently creating such patterns on curved surfaces.

[0097] For example, nanoimprint lithography processes (e.g., J-FIL) using coated resist templates (CRTs) (e.g., including a cover plate for creating a desired pattern) on flexible plastics, glass meshes, or sheets can overcome process barriers experienced in conventional processes (e.g., by allowing control over the volume of patterned material). As disclosed herein, nanoimprint lithography processes using J-FIL and flexible CRTs (e.g., glass, plastics, sheets) advantageously allow (1) the distribution of material with varying refractive indices and / or volumes across any region of a curved surface, and / or (2) the use of a mold (e.g., a thin, flexible mold) to directly conform to the surface (e.g., a curved surface) using capillary forces. Capillary forces can be applied to a thin, controlled-volume resist fluid coating, thereby allowing the formation of micropatterns and / or nanopatterns on a varying TTV surface.

[0098] The magnitude of fluid capillary forces (e.g., associated with patterned materials) can be influenced by fluid flow, flow time, and / or fluid resistance. Fluid dynamics equations can describe these forces and thus describe the contact-based imprinting principle. Equation (1) describes the Young-Laplace equation, where boundary conditions are applied between two surfaces (e.g., between a curved surface and a cover plate) with patterned material (e.g., a resist fluid) and air as the medium.

[0099] (1)

[0100] As described by equation (1), the force acting on each surface is proportional to the area of ​​the patterned material interaction between the two surfaces. The area can have a width w and a length l. r This could be the surface tension of the patterning material (e.g., a photoresist) in the air. The force is inversely proportional to the distance *d* between the two surfaces. In some instances, the distance parameter *d* is important because it may determine the magnitude of the force acting on the surfaces. The control of the distance parameter can be determined by the type of process used to distribute the patterning material under specific conditions.

[0101] Using the Young-Laplace equation and the Navier-Stokes equation for incompressible laminar flow, the time required for capillary filling of a given patterned material can be described in equation (2).

[0102] (2)

[0103] Equation (2) can be further used to understand the magnitude of the laminar flow velocity. The Reynolds number can be calculated, which is the ratio of inertial force to viscous force. For example, the Reynolds number for this type of flow is about 10⁻⁵, and therefore the flow is considered laminar.

[0104] Equations (1) and (2) can provide a generalized approximation trend as shown in Table 1. Table 1 shows exemplary forces applied to a surface for a given material surface tension of 30 mN / m, based on variations in the contact angle (wetting (e.g., less than 5 degrees) vs. non-wetting (e.g., greater than 5 degrees)) and volume / thickness of the patterned material (e.g., resist fluid). Specifically, Table 1 shows the forces, in Newtons, applied per unit area of ​​1 mm x 1 mm due to capillary wetting for resists with varying ultra-low volume fill and resists with varying contact angles.

[0105]

[0106] Table 1

[0107] Table 1 highlights the importance of patterned materials (e.g., wetting resist fluids) that can be distributed at low volume (e.g., corresponding to thicknesses less than 50 nm) to achieve high capillary forces (e.g., greater than or equal to 1 N per square millimeter) applied to a surface. That is, distributing patterned materials at a thickness of less than 50 nm can achieve capillary forces applied to a surface greater than or equal to 1 N per square millimeter. As described in more detail herein, achieving high capillary forces allows for more efficient creation of micro- or nano-patterns on curved surfaces.

[0108] In some embodiments, the patterning material is a nanoimprint resist that (1) has good wetting properties for filling and / or for volume distribution control and / or (2) requires low release force upon curing. For example, the patterning material may be a resist used in J-FIL type processes, wherein 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 about 30 mN / m. As shown in Table 1, these conditions can allow for high capillary forces. For example, to provide a low volume for achieving high capillary forces, inkjet printing is used to distribute a volume of less than 500 nL of resist over a large area (e.g., 50 mm x 50 mm); on average, droplets smaller than 6 pL are distributed on a square grid of 180 μm x 180 μm.

[0109] In some embodiments, inkjet deposition of patterning materials (e.g., resist fluids) results in lower surface tension compared to spin coating or slot extrusion coating. For example, lower surface tension allows the patterning material to diffuse and fill (e.g., diffuse and fill the stencil) more quickly compared to spin coating materials that may evaporate. Using inkjet, the patterning material advantageously remains in its desired material state and at a lower viscosity, thereby reducing viscous forces. Therefore, lower viscous forces can increase capillary fill time, thus advantageously increasing the capillary forces applied over large areas for imprinting. Furthermore, the lower surface tension and lower viscosity of the fluid form of the resist material achieved by inkjet can reduce patterning defects such as dewetting, unfilling, or underfilling.

[0110] As described above, the contact angle and wetting properties of the resist affect the applied capillary force, which can be influenced by the type of nanogeometry and the resist density compared to a blank surface when the resist is in contact. Regions including nanochannels can help fluids (e.g., patterned materials) flow in a specific direction. By facilitating fluid flow, the diffusion of the patterned material (e.g., the resist) can be increased. By increasing diffusion, the fluid between the two surfaces holding the fluid (e.g., a cladding and a substrate) can be reduced. Reducing the fluid between the two holding surfaces can increase the force (e.g., capillary force) that keeps the two surfaces in contact. As described in more detail herein, the method of applying increased forces between two surfaces allows for the more efficient and reliable creation of micropatterns or nanopatterns on curved surfaces.

[0111] Figures 6A to 6D An exemplary nanochannel arrangement according to embodiments of the present disclosure is shown. Although the nanochannel arrangement is described with respect to a flat surface, it should be understood that this arrangement can be used for curved surfaces. For example, regarding... Figures 6A to 6D The described nanochannel arrangements can be included in relation to Figures 7 to 7. Figure 12 The described curved surface. Although the nanochannel arrangement is described as having a specific pitch and angle, it should be understood that the described geometry is exemplary. The geometry of the nanochannel arrangement on the surface can vary on the surface depending on diffusion requirements (e.g., achieving desired capillary forces at specific locations).

[0112] Figure 6A The side and top views of substrate 600 without nanochannels are shown. As shown, with respect to... Figures 6B to 6D Compared to the described arrangement, the patterned material 602 (e.g., resist fluid) does not diffuse as extensively across the substrate 600. In some examples, as shown, the patterned material can be distributed at a distance of 176 μm.

[0113] Figure 6B A side view and a top view of a substrate 610 including a nanochannel arrangement 614 are shown. In some embodiments, the nanochannel arrangement 614 has a pitch (e.g., the spacing between two adjacent lines of the nanochannel arrangement) and an angle. For example, the nanochannel arrangement 614 has a pitch of 50-500 nm, a linewidth of 10-400 nm, a height of 10-500 nm, and an angle of zero degrees relative to the axis of the substrate 610. The nanochannel arrangement 614 advantageously improves the filling speed of the patterned material. As shown, with respect to... Figure 6A Compared to the described arrangement, the patterned material 612 (e.g., resist fluid) diffuses more extensively across the substrate 610 to create a thinner patterned material layer.

[0114] Figure 6C A side view and a top view of a substrate 620 including a nanochannel arrangement 624 are shown. In some embodiments, the nanochannel arrangement 624 has a pitch (e.g., the spacing between two adjacent lines of the nanochannel arrangement) and an angle. For example, the nanochannel arrangement 624 has a pitch of 50-500 nm, a linewidth of 10-400 nm, a height of 10-500 nm, and an angle of 12 degrees relative to the axis of the substrate 620. The nanochannel arrangement 624 advantageously improves the filling speed of the patterned material. As shown, with respect to... Figure 6A and Figure 6B Compared to the described arrangement, the patterned material 622 (e.g., resist fluid) diffuses more extensively across the substrate 620 to create a thinner patterned material layer.

[0115] Figure 6D A side view and a top view of a substrate 630 including a nanochannel arrangement 634 are shown. In some embodiments, the nanochannel arrangement 634 has a pitch (e.g., the spacing between two adjacent lines of the nanochannel arrangement) and an angle. For example, the nanochannel arrangement 634 has a pitch of 50-500 nm, a linewidth of 10-400 nm, a height of 10-500 nm, and an angle of 22 degrees relative to the axis of the substrate 630. The nanochannel arrangement 634 advantageously improves the filling speed of the patterned material. As shown, with respect to... Figures 6A to 6C Compared to the described arrangement, the patterned material 632 (e.g., resist fluid) diffuses more extensively across the substrate 630 to create a thinner patterned material layer.

[0116] The described nanochannel arrangement can improve the filling rate of patterned material (compared to a surface without a nanochannel arrangement), thereby reducing the gap thickness occupied by the patterned material and exerting greater capillary forces when interacting between two surfaces (e.g., two curved surfaces; a curved substrate and a curved cover). In some embodiments, by using a nanochannel arrangement having a pitch that is the same as its width (i.e., 50% spatial periodicity), for a given filling volume (assuming no unfilled voids), micropatterning or nanopatterning can improve capillary retention (e.g., by a factor of two).

[0117] Figures 7A to 7F The fabrication of exemplary patterns on a curved surface according to embodiments of the present disclosure is illustrated. For example, Figures 7A to 7F The J-FIL process and the use of flexible CRTs for micro- or nano-patterning on curved substrates are illustrated. Although the curved surfaces are shown as having specific convexity and curvature (e.g., specific radii of curvature), it should be understood that the convexity and curvature shown are exemplary. In some embodiments, patterns can be created on convex or concave curved surfaces with different curvatures using the disclosed process. Although patterns are shown across one dimension, it should be understood that patterns can be created across more than one dimension.

[0118] Figure 7A A patterned material 702 deposited on a curved surface 700 is shown. In some embodiments, the patterned material 702 is a resist fluid (e.g., a UV-curable resist), and the patterned material 702 is deposited using inkjet printing as described herein. In some embodiments, the volume of each deposit is precisely controlled (e.g., to achieve desired thickness and capillary force). For the sake of brevity, the description and advantages of inkjet printing are not repeated here. In some embodiments, the curved surface 700 has a height of less than 20 mm from its center to its edge. It should be understood that the patterned material 702 can be deposited in different sequences (e.g., all droplets simultaneously, one droplet at a time, more than one droplet at a time).

[0119] In some embodiments, such as regarding Figures 6A to 6D As described, the curved surface 700 includes a nanochannel arrangement. The nanochannel arrangement advantageously allows the patterned material 702 to diffuse over a wider area, thereby allowing for a reduction in the thickness of the patterned material and achieving greater capillary forces for creating the desired pattern.

[0120] In some embodiments, the location of the patterned material 702 deposit corresponds to a desired pattern (e.g., micropattern, nanopattern). For example, the center of the deposited patterned material corresponds to the periodicity of the desired pattern (e.g., pattern pitch) to be molded by the cover plate. Specifically, the location of the deposit can allow sufficient capillary force (as described with respect to equations (1) and (2) and Table 1) to efficiently and reliably create the desired pattern using a CRT. Furthermore, the desired pattern can become an imprint or mold for creating optical patterns on curved optical elements (e.g., optical patterns on curved waveguides, anti-reflective features on curved optical elements).

[0121] Figure 7B A patterned material 702 and a cover plate 704 deposited on a curved surface 700 are shown. In some embodiments, as shown, the deposited patterned material 702 is positioned to correspond to a desired pattern (e.g., micropattern, nanopattern) to be molded by the cover plate. In some embodiments, the cover plate 704 is a CRT, and the CRT molds the patterned material 702 into the desired pattern. For example, the CRT is a flexible CRT comprising PC or polyethylene terephthalate (PET) and having a thickness of 50-550 μm. In some embodiments, the cover plate 704 has an elastic modulus E of less than 10 GPa (e.g., at a thickness of 50-550 μm).

[0122] Figure 7C A cover plate 704 is shown applied to a patterned material 702 and a curved surface 700. The cover plate 704 can mold the patterned material 702 into a desired pattern. In some embodiments, capillary forces are generated on the patterned material 702 due to the interaction between the patterned material 702 and the surfaces of the curved surface 700 and the cover plate 704. For example, the capillary forces can be described with respect to equations (1) and (2) and Table 1. In some embodiments, the thickness of the patterned material can be reduced due to the nanochannel arrangement and the characteristics of the cover plate, and stronger capillary forces can be achieved to effectively and reliably create desired micro- or nano-patterns on the curved surface (e.g., sufficient force can be applied to allow the CRT to effectively and reliably create the desired pattern on the patterned material 702). Figure 9 An exemplary process for positioning the cover plate 704 is described in more detail.

[0123] Referring back to Table 1, when considering the type of cladding (e.g., CRT) used to form enclosed spaces filled with patterned material of a specific volume, the magnitude of the force per unit 1mm x 1mm area may be important. For example, these considerations include the cladding's bending capacity and / or the maximum deflection of the cladding due to bending.

[0124] The Euler-Bernoulli beam equation shown in equation (3) can give an idea of ​​the deflection and / or the required force achieved by bending a certain distance for a specific type of cladding material (e.g., CRT) with a specific thickness.

[0125] (3)

[0126] Equation (3) can be used to determine the type of cladding or CRT used to form enclosed spaces and create micro or nanopatterns, as described herein. In Equation (3), q is a constant force on a length L (e.g., the length of the cladding) of a material (e.g., the cladding material) having an elastic modulus E and a second moment on an area perpendicular to the load I. The result of Equation (3) produces a maximum deflection D at the center (e.g., the center of the CRT). C This equation can represent a slice from the edge to the center of, for example, a spherical embossing (e.g., a lens-type profile).

[0127] Using Equation (3) and understood as the capillary force applied to maintain curvature (e.g., from the relationships in Table 1), Table 2 shows resist volume thicknesses below 250 nm that can be maintained. Specifically, Table 2 shows the maximum deflection, in mm, on a 20 mm long polycarbonate (PC)-based CRT at thicknesses of 50–550 μm, by applying different forces based on Table 1 at specific resist gap thicknesses and resist contact angles:

[0128]

[0129] Table 2

[0130] Figure 7D The patterned material 702, cured after a cover plate 704 is applied to a patterned material 702 and a curved surface 700, is shown. For example, the patterned material 702 is a UV-curable resist, the patterned material 702 is cured using UV light, and a pattern is created on the patterned material 702 based on the pattern of the cover plate. In some embodiments, after the cover plate 704 is applied and during the curing of the patterned material 702, a force is applied across the patterned material due to the volume of the patterned material deposit, the diffusion of the patterned material (e.g., caused by the arrangement of nanochannels on the curved surface), and / or the thickness of the patterned material (e.g., based on cover plate properties, diffusion, and / or the application of the cover plate). The applied force can be sufficiently large to allow the desired pattern to be effectively and reliably formed on the curved surface and under the cover plate.

[0131] Figure 7EThe diagram shows the cover plate 704 removed after the patterned material 702 has finished curing. In some embodiments, the cover plate 704 is peeled off after the patterned material 702 has finished curing and has formed the desired micro or nanopatterns on the curved surface 700.

[0132] In some instances, template release can depend on the interaction between the cured resist surface and the template surface (e.g., the surface of the cover plate), the pattern density, and the complexity of the pattern being created (e.g., recessed shapes, sloping sidewalls). Release requirements from the cover plate may depend on adhesion to the substrate type. In some embodiments, the bonding between the patterned material and the substrate is enhanced via additional covalent bonding chemistry.

[0133] Figure 7F A pattern 706 created on a curved surface 700 is shown. In some embodiments, the pattern 706 is based on the pattern of the cladding and the force acting on the patterned material 702 during material curing. For example, the force is based on the volume of the deposited patterned material 702, the diffusion of the patterned material (e.g., caused by the arrangement of nanochannels on the curved surface), and / or the thickness of the patterned material (e.g., based on cladding properties, diffusion, and / or the application of the cladding).

[0134] In some embodiments, pattern 706 can be used to create antireflective features (e.g., antireflective nanopatterns) on a lens. For example, pattern 706 can be part of a mold; the lens and its antireflective pattern can advantageously be formed together with the mold (i.e., pattern 706) in a single step (e.g., without antireflective film deposition). In some embodiments, pattern 706 can be used (e.g., as a mold) to create waveguide patterns (e.g., on curved glass, on curved plastic, on patterned geometric phase (GP) (e.g., based on liquid crystal materials), on a curved substrate, or on a waveguide or metalens pattern with a small form factor on a curved substrate (e.g., a contact lens)).

[0135] In some embodiments, pattern 706 is coated with a release layer to form a pattern transfer surface (e.g., for demolding when pattern 706 is used as a mold). For example, the release layer coating comprises SiO2, Au, Al, or Al2O3 with or without fluorosilane treatment (e.g., FOTS).

[0136] In some embodiments, regarding Figures 7A to 7F The described process advantageously allows for the efficient and reliable creation of micro- or nano-patterns on curved surfaces. By using the disclosed nanochannel arrangement, cladding, and / or patterned material deposition process, forces can be applied to create patterns with the patterned material (e.g., sufficiently strong capillary forces for creating desired patterns on curved surfaces and under cladding).

[0137] In some embodiments, pattern 706 is transferred to a curved surface via an etching process such as reactive ion etching (RIE), inductively coupled plasma RIE, ion beam polishing, and etching using gases such as CHF3, CF3, SF6, Cl2, O2, and Ar. The curved surface 700 may comprise materials such as fused silica (SiO2), quartz (SiO2), chromium-coated fused silica, or soda lime. The etched pattern may also be transferred to a thin film deposited on the curved surface using physical vapor deposition processes (e.g., evaporation, sputtering) and / or chemical vapor deposition processes (e.g., plasma-enhanced CVD, atomic layer deposition). Such films may include silicon nitride (Si3N4), silicon oxynitride, and silicon dioxide (SiO2). It should be understood that other processes, gases, and materials may be used to transfer the pattern.

[0138] In some embodiments, the micro- or nano-patterns may vary across the curved regions covered by the cover plate. In some embodiments, the type of resist applied may vary across the curved regions covered by the substrate (e.g., to change surface tension, viscosity, or contact angle) to optimize capillary retention for different curvature depths (e.g., to form the varied micro- or nano-patterns).

[0139] Figures 8A to 8C The fabrication of an exemplary pattern on a curved surface according to an embodiment of the present disclosure is illustrated. Although the curved surface is shown as having a specific convexity and curvature (e.g., a specific radius of curvature), it should be understood that the convexity and curvature shown are exemplary. In some embodiments, patterns can be created on convex or concave curved surfaces with different curvatures using the disclosed process. Although patterns are shown across one dimension, it should be understood that patterns can be created across more than one dimension. Although specific variations in parameters are described, it should be understood that other parameters can be changed to create desired variations in patterns. For the sake of brevity, details regarding... Figures 7A to 7F The steps, features, and advantages described.

[0140] Figure 8A A patterned material 802 deposited on a curved surface 800 is shown. In some embodiments, as shown, the volume of the deposited patterned material 802 (e.g., using inkjet printing) varies across the curved surface 800 (e.g., 10 pL to 10 μL). For example, the deposition volume closer to the edge of the curved surface 800 may be smaller than the deposition volume closer to the center of the curved surface 800.

[0141] Due to the varying volumes, the thickness across the patterned material 802 (e.g., the distance between the curved surface 800 and the cover plate 804 at locations across the patterned material) can vary after the application of the cover plate 804 (e.g., to ensure proper curvature and conformal coverage). For example, as shown, the deposition volume closer to the edge of the curved surface 800 is smaller than the deposition volume closer to the center of the curved surface 800, and the first thickness 806 closer to the edge of the curved surface 800 is thinner than the second thickness 808 closer to the center of the curved surface 800. Therefore, the pattern 810 corresponding to the first thickness 806 is at a lower height relative to the curved surface 800 compared to the pattern 812 corresponding to the second thickness 808. The relationship between volume, thickness, and the created pattern can be predicted as described with respect to equations (1) and (2) and Table 1.

[0142] Figure 8B Patterned materials 822A and 822B are shown deposited on a curved surface 820. In some embodiments, as shown, the deposition associated with patterned material 822A is diffused differently compared to the deposition associated with patterned material 822B (e.g., using inkjet printing). In some embodiments, the diffusion is different because patterned material 822A comprises a different material than patterned material 822B.

[0143] For example, different materials may include materials with different refractive indices (e.g., a first material with a refractive index of 1.53 (e.g., patterned material 822A) and a second material with a refractive index of 1.9 (e.g., patterned material 822B)). The first material may include UV-curable polymers such as acrylates and vinyl esters. The second material may include sulfur, aromatic molecules in carbon chains, or high-refractive-index nanoparticles such as TiO2 and ZrO2. More generally, in some embodiments, the patterned materials disclosed herein include the first material, the second material, or both the first material and the second material.

[0144] In some embodiments, the diffusion differs because the nanochannel arrangement associated with patterned material 822A (e.g., a nanochannel arrangement located on a curved surface of the corresponding deposited material) differs from that of patterned material 822B. For example, the nanochannel arrangement associated with patterned material 822A allows patterned material 822A to diffuse more than that of patterned material 822B.

[0145] Due to the diffusion of the change, the thickness across the patterned materials 822A and 822B (e.g., the distance between the curved surface 820 and the cover plate 824 at the location across the patterned materials) can vary after the application of the cover plate 824. For example, as shown, the first thickness 826 corresponding to the patterned material 822A is thinner than the second thickness 828 corresponding to the patterned material 822B. Therefore, the pattern 830 corresponding to the patterned material 822A is at a lower height relative to the curved surface 800 compared to the pattern 832 corresponding to the patterned material 822B. The relationship between volume, thickness, and the created pattern can be predicted as described with respect to equations (1) and (2) and Table 1.

[0146] Figure 8C Patterned materials 842A and 842B are shown deposited on a curved surface 840. In some embodiments, as shown, patterned material 822A is deposited at different intervals (e.g., using inkjet printing) compared to the deposition location of patterned material 842B. For example, patterned material 842A is deposited between wider intervals (e.g., larger gaps between adjacent deposits) than the deposition of patterned material 842B. In some embodiments, patterned materials 824A and 824B comprise the same material.

[0147] Due to the varying deposition locations, the thickness across patterned materials 842A and 842B (e.g., the distance between the curved surface 840 and the cover plate 844 at locations across the patterned materials) can vary after the cover plate 844 is applied. For example, as shown, a first thickness 846 corresponding to patterned material 842A is thinner than a second thickness 848 corresponding to patterned material 842B.

[0148] Different thicknesses can correspond to different patterns created by the cover plate 844. For example, a first thickness 846 can be a thickness sufficient to apply a force to create pattern 850 (e.g., based on equations (1) and (2) and Table 1), and a second thickness 848 can be a thickness sufficient to apply a force to create pattern 852. Thus, sufficient force corresponding to the pattern to be created can be applied based on the thickness. The force used to create pattern 850 can be greater than the force used to create pattern 852, and therefore a thinner thickness is required to apply a larger capillary force to create pattern 850. The relationship between volume, thickness, and created pattern can be predicted as described with respect to equations (1) and (2) and Table 1.

[0149] In some embodiments, Figures 8A to 8CThe pattern created is coated with a release layer to form a pattern transfer surface (e.g., for demolding when the pattern is used as a mold). For example, the release layer coating comprises SiO2, Au, Al, or Al2O3 with or without fluorosilane treatment (e.g., FOTS).

[0150] In some instances, the ability to initiate surface contact with the bent surface using a resist may be required to provide the necessary power for bending and conforming of the cover (e.g., flexible CRT). Figure 9 An exemplary force transfer method for creating patterns on a curved surface is illustrated according to an embodiment of the present disclosure. This force can be transferred to position the cover plate 910 onto the patterned material. For example, as per [reference to...] Figures 7A to 7F and Figures 8A to 8C As described, a force can be applied by rollers 900A or 900B or mechanism 902A or 902B to bend the cover (e.g., to achieve a desired cover curvature and thus a desired distance between the cover and the bent surface) and initiate contact between the cover and the patterned material until capillary forces (e.g., based on the characteristics and thickness of the patterned material and the distance between the cover and the bent surface) hold the cover in its patterned position.

[0151] In some embodiments, concave / convex push rollers 900A or 900B (e.g., up-down, left-right) are used to provide forces for positioning the cover plate (e.g., by rolling rollers on top of the cover plate 910 so that the cover plate 910 contacts the patterned material used to form the micro- or nano-patterns described herein (below the cover plate)). In some embodiments, compatible Z-head mechanisms 902A or 902B are used to provide forces for positioning the cover plate (e.g., by utilizing up-down movement so that the cover plate 910 contacts the patterned material used to form the micro- or nano-patterns described herein (below the cover plate)).

[0152] In some embodiments, non-contact methods, such as using pressurized inert gas, air, or generating a pressure differential (e.g., by generating a lower pressure section), can be used to generate forces for positioning the cover plate (e.g., flexible CRT) and forming specific micro or nanopatterns.

[0153] For example, using the disclosed process for contacting the cladding with the patterned material, embossing can be achieved on a curved surface with a diameter of 50 mm using a flexible CRT (e.g., a co-extruded PC or PET mesh / roll with a thickness of 50-550 μm) onto an NBK-7 lens (n ​​= 1.53) with a refractive power of -1D. In this example, the flexible CRT can have a curvature depth of 600 μm at the center relative to the edge. When the CRT is pushed against the curved surface using the disclosed process, the CRT advantageously conforms to and maintains the shape of the curvature. In some examples, the cladding can have the additional benefit of flattening any scratches or voids (e.g., haze) on the curved surface.

[0154] Figures 10A to 10E An exemplary application of patterns created on a curved surface according to embodiments of the present disclosure is illustrated. Although the curved surface is shown as having a specific concavity and curvature (e.g., a specific radius of curvature), it should be understood that the concavity and curvature shown are exemplary. In some embodiments, patterns can be created on concave or convex curved surfaces with different curvatures using the disclosed process. Although patterns are shown across one dimension, it should be understood that patterns can be created across more than one dimension. For the sake of brevity, references to Figures 7 to 7 are not repeated here. Figure 9 The steps, features, and advantages described.

[0155] Figure 10A A patterned material 1002 deposited on a curved surface 1000 is shown. The patterned material 1002 may include, but is not limited to, patterns related to... Figures 7A to 7F and Figures 8A to 8C The patterned material described herein. In some embodiments, the patterned material 1002 is a resist fluid (e.g., a UV-curable resist), and the patterned material 1002 is deposited using inkjet printing, as described herein. In some embodiments, the volume of each deposit is precisely controlled (e.g., to achieve desired thickness and capillary force). For the sake of brevity, the description and advantages of inkjet printing are not repeated herein. It should be understood that the patterned material 1002 can be deposited in different sequences (e.g., all droplets simultaneously, one droplet at a time, more than one droplet at a time).

[0156] Figure 10B A patterned material 1002 deposited on a curved surface 1000 is shown. In some embodiments, Figure 10B As shown in the example about Figures 7A to 7F and Figures 8A to 8C The curved surface 1000 and patterned material 1002 described before the application of the cover plate. Figure 10C A pattern 1006 created on a curved surface 1000 is shown. Pattern 1006 can be used as shown in Figures 7 to 7. Figure 9 The process described is used to create it.

[0157] Figure 10D A patterned material 1008 deposited on a curved surface 1000 is shown. The patterned material 1008 may include, but is not limited to, patterns related to... Figures 7A to 7F and Figures 8A to 8C The patterned material described. In some embodiments, the patterned material 1008 is a resist fluid (e.g., a UV-curable resist), and the patterned material 1008 is deposited using a non-inkjet method, as in inkjet (e.g., as per [reference to inkjet printing]). Figure 10AAlternatives to the described method. In some embodiments, the volume of each deposit is precisely controlled (e.g., to achieve the desired thickness and capillary force).

[0158] Figure 10E It shows the use as inkjet (e.g., as about Figure 10B The described alternative (inkjet) method deposits patterned material 1008 on the curved surface 1000. In some embodiments, Figure 10E The curved surface 1000 and patterned material 1008 before the cladding are applied are shown, as per [reference to...]. Figures 7A to 7F and Figures 8A to 8C As described. Patterned material 1008 can be used as shown in Figures 7 to 7. Figure 9 The description and such as about Figure 10C The described process forms pattern 1006.

[0159] Figures 11A to 11D An exemplary application of a pattern manufactured on a curved surface according to embodiments of the present disclosure is shown. Although the pattern is shown across one dimension, it should be understood that patterns can be created across more than one dimension.

[0160] Figure 11A A first mold 1100A and a second mold 1100B are shown. The first mold 1100A includes a first pattern 1102, and the second mold 1100B includes a second pattern 1104. In some embodiments, unlike the illustration, both the first mold and the second mold are either concave or convex. In some embodiments, using figures 7 to... Figure 9 The described process creates pattern 1102 and / or pattern 1104. In some embodiments, pattern 1102 and / or pattern 1104 are coated with a release layer to form a pattern transfer surface (e.g., for demolding when the pattern is used as a mold). For example, the release layer coating comprises SiO2, Au, Al, or Al2O3 with or without fluorosilane treatment (e.g., FOTS).

[0161] Figure 11B Material 1106 is shown placed between a first mold 1100A and a second mold 1100B. In some embodiments, material 1106 is a material used to manufacture optical structures (e.g., waveguides, optical structures with anti-reflective features). For example, material 1106 is a curable waveguide resin.

[0162] In some embodiments, material 1106 is molded between a first mold 1100A and a second mold 1100B. For example, a curable waveguide resin is molded between the two molds. The patterns 1102 and 1104 and the curvature of the two molds are determined based on the desired radius of curvature of the final product created by molds 1100A and 1100B. For example, the desired radius of curvature is the desired waveguide radius of curvature, and the waveguide has patterns corresponding to patterns 1102 and 1104. The curvature of the two molds can be used with reference to Figures 7 to... Figure 9 The process described is used to create it.

[0163] Figure 11C The final product 1108 is shown. In some embodiments, the final product 1108 is a waveguide having a desired radius of curvature and pattern (e.g., a first optical pattern 1110, a second optical pattern 1112) that enable desired optical properties. In some embodiments, the first pattern 1102 corresponds to the first optical pattern 1110 (e.g., by molding material 1106 into the first pattern 1102 to form the first optical pattern 1120), and the second pattern 1104 corresponds to the second optical pattern 1112 (e.g., by molding material 1106 into the second pattern 1104 to form the second optical pattern 1112).

[0164] In some embodiments, the first optical pattern 1110 and / or the second optical pattern 1112 includes one or a combination of the following: an input coupling element that diffracts incident light from a light source into the substrate by total internal reflection; a pupil expansion element that helps guide and diffuse light to the vicinity of the user's eye; an exit pupil or coupling element that extracts light from the user to generate a virtual image; or an anti-reflection pattern for increasing transmittance.

[0165] In some embodiments, the final product 1108 is a refractive lens with anti-reflective features. As an example, the lens curvature can have a radius aperture of 20 mm, a lens refractive power of + / - 1.25D, and a radius of curvature of 425 mm. The height or depth of the curvature is approximately 450 μm for a 1.53 refractive index lens material, approximately 400 μm for a 1.65 refractive index lens material, and greater than 350 μm for a 1.75 refractive index lens material.

[0166] Figure 11DThe desired optical characteristics associated with the pattern of the final product 1108 are shown. For example, the final product 1108 is a waveguide of an MR system (as described with respect to Figures 1 through 5), and the pattern 1110 corresponds to a focal point 1114 with a specific depth of focus corresponding to an MR image. When MR content is presented to a user, a light source 1116 is optically coupled to the waveguide to provide light for presenting the MR content. The pattern 1110 improves the presentation of the MR image because it is configured to focus at the focal point 1114 corresponding to the MR image.

[0167] In some embodiments, regarding Figures 7 to Figure 9 The described process allows for the creation of molds 1100A and 1100B, and makes the manufacture of the final product 1108 more feasible. As an example advantage, compared to conventional methods, regarding... Figures 11A to 11D The process described for forming the final product 1108 could be more efficient. For example, if the final product 1108 is a waveguide, the process could avoid the need for post-annealing of a flat polymer waveguide substrate on a curved solid surface to create a specific curvature. The additional post-annealing step could be more time-consuming, less reliable, and more expensive.

[0168] In some embodiments, the system (e.g., the MR system described herein) includes a wearable head device (e.g., an MR device, the wearable head device described herein), the wearable head device including a display. In some embodiments, the display includes an optical stack including optical features (e.g., a final product 1108 including pattern 1110 and / or pattern 1112), and uses the information from Figures 6 to 1998. Figure 12 The described process or method forms optical features. In some embodiments, the system includes one or more processors configured to perform a method including presenting content associated with a mixed reality environment on a display, wherein the content is presented based on optical features.

[0169] Figure 12 An exemplary method 1200 for creating a pattern on a curved surface according to an embodiment of the present disclosure is shown. Although method 1200 is shown as including the described steps, it should be understood that steps in a different order, additional steps, or fewer steps may be included without departing from the scope of the present disclosure. For the sake of brevity, some of the advantages and patterns described with respect to Figures 5 through 11 are not described herein.

[0170] In some embodiments, method 1200 includes: depositing a patterned material on a curved surface (step 1202). For example, as per [reference to...] Figures 7A to 7F , Figures 8A to 8C and Figures 10A to 10CAs described, patterned materials (e.g., patterned materials 702, 802, 822A, 822B, 842A, 844B, 1002) are deposited on a curved surface. In some embodiments, depositing the patterned material on the curved surface includes inkjet patterned materials. For example, as per [reference to...] Figures 7A to 7F , Figures 8A to 8C and Figures 10A to 10C As described, inkjet printing is used to deposit patterned materials (e.g., patterned materials 702, 802, 822A, 822B, 842A, 844B, 1002) onto a curved surface.

[0171] In some embodiments, the curved surface includes one or more nanochannel arrangements. For example, as per [reference to...] Figures 6B to 6D , Figures 7A to 7F , Figures 8A to 8C and Figures 10A to 10C The described, disclosed curved surface includes one or more nanochannel arrangements. In some embodiments, method 1200 includes: diffusing a patterned material over the nanochannel arrangement. For example, as per [reference to...] Figures 6B to 6D , Figures 7A to 7F , Figures 8A to 8C and Figures 10A to 10C As described, the arrangement of one or more nanochannels on a curved surface facilitates the diffusion of patterned materials.

[0172] In some embodiments, each of one or more nanochannel arrangements is arranged at an angle of zero, twelve, or twenty-two degrees relative to the edge of the curved surface. For example, as per [reference to...] Figures 6B to 6D , Figures 7A to 7F , Figures 8A to 8C and Figures 10A to 10C As described, one or more nanochannel arrangements (e.g., nanochannel arrangements 614, 624, 634) are arranged at an angle of zero, twelve, or twenty-two degrees relative to the edge of the curved surface.

[0173] In some embodiments, method 1200 includes: positioning a cover plate on a patterned material (step 1204). In some embodiments, the cover plate includes a template for creating the pattern. For example, as per [reference to...] Figures 7A to 7F , Figures 8A to 8C , Figure 9 and Figures 10A to 10C As described, the cladding (e.g., cladding 704, 804, 824, 844, 910) is positioned on a patterned material.

[0174] In some embodiments, the cladding includes a flexibly coated resist template. For example, as per [reference to...] Figures 7A to 7F , Figures 8A to 8C , Figure 9 and Figures 10A to 10CAs described, the cladding (e.g., cladding 704, 804, 824, 844, 910) comprises a flexible CRT. In some embodiments, the cladding comprises polycarbonate. For example, as per [reference to...] Figures 7A to 7F , Figures 8A to 8C , Figure 9 and Figures 10A to 10C As described, the cladding (e.g., cladding 704, 804, 824, 844, 910) comprises PC, PET, or both. In some embodiments, the cladding has a thickness of 50-550 μm. For example, as per [reference to...] Figures 7A to 7F , Figures 8A to 8C , Figure 9 and Figures 10A to 10C As described, the cladding (e.g., cladding 704, 804, 824, 844, 910) has a thickness of 50-550 μm. In some embodiments, the cladding has an elastic modulus E of less than 10 GPa (e.g., at a thickness of 50-550 μm). For example, as per [reference to...] Figures 7A to 7F , Figures 8A to 8C , Figure 9 and Figures 10A to 10C As described, the cladding (e.g., cladding 704, 804, 824, 844, 910) has an elastic modulus E of less than 10 GPa.

[0175] In some embodiments, positioning the cover plate on a patterned material includes applying a force to the cover plate to bend it toward a curved surface. For example, as per [reference to...] Figures 7A to 7F , Figures 8A to 8C , Figure 9 and Figures 10A to 10C As described, a force is applied to the cladding (e.g., cladding 704, 804, 824, 844, 910) to cause the cladding to bend toward the curved surface.

[0176] In some embodiments, a force is applied to the cover plate using rollers or a mechanism. For example, as per [reference to...] Figures 7A to 7F , Figures 8A to 8C , Figure 9 and Figures 10A to 10C As described, a force is applied to a cover plate (e.g., cover plate 704, 804, 824, 844, 910) using rollers (e.g., rollers 900A, 900B) or mechanisms (e.g., mechanisms 902A, 902B).

[0177] In some embodiments, forces on the cladding maintain a distance between the cladding and the curved surface, and this distance corresponds to the applied force. For example, as per [reference to...] Figures 7A to 7F , Figures 8A to 8C , Figure 9 and Figures 10A to 10CAs described, the force applied to the cover plate (e.g., cover plate 704, 804, 824, 844, 910) maintains the distance between the cover plate and the curved surface, and the applied capillary force (e.g., as described with respect to Table 1) is related to this distance.

[0178] In some embodiments, method 1200 includes applying a force between a curved surface and a cover plate using a patterned material (step 1206). In some embodiments, the force includes capillary forces. For example, as per [reference to...] Figures 7A to 7F , Figures 8A to 8C and Figures 10A to 10C As described, capillary forces (as described with respect to Table 1) are applied between the curved surface and the cladding. This force can be sufficient to reliably create patterns using a template with patterned materials and cladding.

[0179] In some embodiments, the force is based on the thickness of the patterned material, the contact angle of the patterned material, or both. For example, as per [reference to...] Figures 7A to 7F , Figures 8A to 8C and Figures 10A to 10C As described in Table 1, the magnitude of the capillary force applied between the curved surface and the cover plate is a function of the thickness of the patterned material, the contact angle of the patterned material, or both. In some embodiments, the force maintains the position of the applied cover plate relative to the curved surface. For example, the capillary force maintains the distance between the cover plate and the curved surface in the absence of a force applied to the cover plate.

[0180] In some embodiments, method 1200 includes: after applying a force between the curved surface and the cover plate, stopping the application of force on the cover plate. For example, as per [reference to...] Figures 7A to 7F , Figures 8A to 8C , Figure 9 and Figures 10A to 10C As described, after the desired capillary force is applied between the cover plate and the curved surface, the capillary force can maintain the distance between the cover plate and the curved surface without any force applied to the cover plate; the application of force to the cover plate can be stopped.

[0181] In some embodiments, method 1200 includes: curing a patterned material (step 1208). In some embodiments, the cured patterned material includes a pattern. For example, as per [reference to...] Figures 7A to 7F , Figures 8A to 8C , Figures 10A to 10C and Figures 11A to 11D As described, a patterned material is cured (e.g., using UV light), and the cured patterned material includes a pattern (e.g., pattern 706, 810, 812, 830, 832, 850, 852, 1006, 1102, 1104) from a template of the cover plate.

[0182] In some embodiments, method 1200 includes removing the cover plate (step 1210). For example, as per [reference to...] Figures 7A to 7F , Figures 8A to 8C , Figures 10A to 10C and Figures 11A to 11D As described, after creating a pattern (e.g., patterns 706, 810, 812, 830, 832, 850, 852, 1006, 1102, 1104), the cover plate is removed. In some embodiments, method 1200 includes: bonding a patterned material to a curved surface via covalent bonds. For example, to increase the bonding strength between the patterned material and the curved surface and to reduce potential damage to the pattern during cover plate removal, the patterned material is covalently bonded to the curved surface.

[0183] In some embodiments, method 1200 includes: forming an optical structure using a pattern. For example, as per [reference to...] Figures 11A to 11D As described, patterns 1102 and 1104 are used to form the final product 1108. In some embodiments, the optical structure is formed by molding a curable resin using a pattern. For example, as per [reference to...] Figures 11A to 11D As described, the final product 1108 is formed using a molding material 1106 (e.g., a curable resin). In some embodiments, the final product 1108 comprises a molded polymer.

[0184] In some embodiments, the optical structure includes a bent waveguide. For example, as per [reference to...] Figures 11A to 11D As described, the final product 1108 includes a bent waveguide. In some embodiments, the pattern corresponds to the focal point of the bent waveguide. For example, as per [reference to...] Figures 11A to 11D As described, the curved waveguide includes optical patterns 1110 and 1112 formed by patterns 1102 and 1104, and the optical patterns correspond to a focal point 1114 for displaying MR content.

[0185] In some embodiments, the optical structure includes a lens having anti-reflective features corresponding to the pattern. For example, as per [reference to...] Figures 11A to 11D As described, the final product 1108 includes a lens having anti-reflective features formed by patterns 1102 and / or 1104.

[0186] In some embodiments, method 1200 includes: applying a pattern with a release layer. For example, as per [reference to...] Figures 7A to 7F , Figures 8A to 8C , Figures 10A to 10C and Figures 11A to 11DAs described, after creating patterns (e.g., patterns 706, 810, 812, 830, 832, 850, 852, 1006, 1102, 1104), a release layer is applied to the patterns to facilitate demolding of the final product (e.g., final product 1108) molded from the patterns (e.g., pattern 1102 of mold 1100A, pattern 1104 of mold 1100B).

[0187] In some embodiments, a first patterned material has a first volume, and the first patterned material is deposited at a first location relative to a curved surface. In some embodiments, method 1200 includes depositing a second patterned material having a second volume at a second location relative to a curved surface. In some embodiments, a first thickness of the first patterned material at the first location corresponds to the thickness of the first volume, and a second thickness of the second patterned material at the second location corresponds to the thickness of the second volume. For example, as per [reference to...] Figure 8A As described, patterns 810 and 812 are formed by changing the deposition volume of pattern material 802.

[0188] In some embodiments, the first patterned material comprises a first material, and the first patterned material is deposited at a first location relative to a curved surface. In some embodiments, method 1200 comprises depositing a second patterned material comprising a second material at a second location relative to a curved surface. In some embodiments, a first thickness of the first patterned material at the first location corresponds to a characteristic of the first material, and a second thickness of the second patterned material at the second location corresponds to a characteristic of the second material. For example, as per [reference to...] Figure 8B As described, pattern 830 is formed based on patterned material 822A, and pattern 832 is formed based on patterned material 822B. The properties of patterned material 822A cause it to diffuse in a first manner. Due to the diffusion of patterned material 822A, a first thickness 826 is created, and a first capillary force is applied based on the first thickness 826. The properties of patterned material 822B cause it to diffuse in a second manner. Due to the diffusion of patterned material 822B, a second thickness 828 is created, and a second capillary force is applied based on the second thickness 8260.

[0189] In some embodiments, a first patterning material is deposited at a plurality of first locations on a curved surface, the first locations being separated by a first spacing, and the cured patterning material further includes a second pattern. In some embodiments, method 1200 includes depositing a second patterning material at a plurality of second locations on a curved surface, the second locations being separated by a second spacing. In some embodiments, the first spacing corresponds to a first thickness for applying a first force for creating the first pattern, and the second spacing corresponds to a second thickness for applying a second force for creating the second pattern. For example, as per [reference to...] Figure 8C As described, patterned material 842A is deposited on a curved surface at a first location separated by a first interval, and patterned material 842B is deposited on a curved surface at a second location separated by a second interval. The first interval corresponds to a first thickness 846 for applying a first force to create a first pattern 850, and the second interval corresponds to a second thickness 848 for applying a second force to create a second pattern 852.

[0190] According to some embodiments, a method includes: depositing a patterned material on a curved surface; positioning a cover plate on the patterned material, the cover plate including a template for creating a pattern; applying a force between the curved surface and the cover plate using the patterned material; curing the patterned material, wherein the cured patterned material includes a pattern; and removing the cover plate.

[0191] According to some embodiments, the method further includes: forming an optical structure using a pattern.

[0192] According to some embodiments, the optical structure is formed by molding a curable resin using a pattern.

[0193] According to some embodiments, the optical structure includes a bent waveguide.

[0194] According to some embodiments, the pattern corresponds to the focal point of the curved waveguide.

[0195] According to some embodiments, the optical structure includes a lens having anti-reflective features corresponding to a pattern.

[0196] According to some embodiments, the curved surface includes one or more nanochannel arrangements.

[0197] According to some embodiments, each of one or more nanochannel arrangements is arranged at an angle of zero, twelve, or twenty-two degrees relative to the edge of the curved surface.

[0198] According to some embodiments, the method further includes: diffusing patterned material onto a nanochannel arrangement.

[0199] According to some embodiments, the force includes capillary force.

[0200] According to some embodiments, the force is based on the thickness of the patterned material, the contact angle of the patterned material, or both.

[0201] According to some embodiments, the force maintains the position of the applied cladding relative to the curved surface.

[0202] According to some embodiments, depositing patterned materials on curved surfaces includes inkjet patterned materials.

[0203] According to some embodiments, positioning the cover plate on a patterned material includes applying a force to the cover plate to bend it toward a curved surface.

[0204] According to some embodiments, a force is applied to the cover plate using a roller or mechanism.

[0205] According to some embodiments, the force on the cover plate maintains the distance between the cover plate and the curved surface, and this distance corresponds to the applied force.

[0206] According to some embodiments, the method further includes: after applying a force between the curved surface and the cover plate using a patterned material, stopping the application of force on the cover plate.

[0207] According to some embodiments, the cladding includes a flexibly coated resist template.

[0208] According to some embodiments, the cladding includes PC, polyethylene terephthalate, or both.

[0209] According to some embodiments, the cladding has a thickness of 50-550 μm.

[0210] According to some embodiments, the cladding has an elastic modulus of less than 10 GPa.

[0211] According to some embodiments, the method further includes: applying a release layer to the pattern.

[0212] According to some embodiments, the method further includes bonding the patterned material to the curved surface via covalent bonds.

[0213] According to some embodiments, a first patterned material has a first volume, and the first patterned material is deposited at a first location relative to a curved surface. The method further includes depositing a second patterned material having a second volume at a second location relative to the curved surface. A first thickness of the first patterned material at the first location corresponds to the thickness of the first volume, and a second thickness of the second patterned material at the second location corresponds to the thickness of the second volume.

[0214] According to some embodiments, the first patterned material comprises a first material, and the first patterned material is deposited at a first location relative to a curved surface. The method further includes depositing a second patterned material comprising a second material at a second location relative to the curved surface. A first thickness of the first patterned material at the first location corresponds to characteristics of the first material, and a second thickness of the second patterned material at the second location corresponds to characteristics of the second material.

[0215] According to some embodiments, a first patterning material is deposited at a plurality of first locations on a curved surface, the first locations being separated by a first interval, and the cured patterning material further includes a second pattern. The method further includes depositing a second patterning material at a plurality of second locations on the curved surface, the second locations being separated by a second interval. The first interval corresponds to a first thickness for applying a first force to create the first pattern, and the second interval corresponds to a second thickness for applying a second force to create the second pattern.

[0216] According to some embodiments, the method further includes transferring a pattern onto a curved surface via etching.

[0217] According to some embodiments, the optical stack includes optical features. The optical features are formed using any of the methods described above.

[0218] According to some embodiments, a system includes: a wearable head device including a display. The display includes an optical stack including optical features, and the optical features are formed using any of the methods described above; and one or more processors configured to perform a method including: presenting content associated with a mixed reality environment on the display, wherein the content is presented based on the optical features.

[0219] Although the disclosed examples have been fully described with reference to the accompanying drawings, it should be noted that various changes and modifications will be 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 should be understood to be included within the scope of the disclosed examples as defined in the appended claims.

Claims

1. A method for creating patterns on a curved surface, comprising: A first patterned material is deposited on the curved surface; The cover plate is positioned on the first patterned material, the cover plate including a template associated with the pattern; A force is applied between the curved surface and the cover plate using the first patterned material, wherein the force includes capillary force, wherein the curved surface includes one or more nanochannel arrangements configured to increase the diffusion of the first patterned material on the curved surface to reduce the gap thickness occupied by the first patterned material and increase the capillary force between the curved surface and the cover plate. Curing the first patterned material, the curing resulting in a cured patterned material including the pattern; and Remove the cover plate.

2. The method according to claim 1, further comprising: The pattern is used to form an optical structure.

3. The method according to claim 1, wherein, The force is based on one or more of the thickness of the first patterned material and the contact angle of the first patterned material.

4. The method according to claim 1, wherein, The force maintains the position of the applied cover plate relative to the curved surface.

5. The method according to claim 1, wherein, Depositing the first patterning material on the curved surface includes inkjet printing of the first patterning material.

6. The method according to claim 1, wherein, Positioning the cover plate on the first patterned material includes applying a force to the cover plate to bend it toward the curved surface.

7. The method according to claim 1, wherein, The cladding includes a flexibly coated resist template.

8. The method according to claim 1, wherein, The cladding comprises one or more of polycarbonate and polyethylene terephthalate.

9. The method according to claim 1, wherein, The cladding has a thickness of 50-550 μm.

10. The method according to claim 1, wherein, The cladding has an elastic modulus of less than 10 GPa.

11. The method according to claim 1, further comprising: The pattern is coated with a release layer.

12. The method according to claim 1, further comprising: The first patterned material is bonded to the curved surface via covalent bonds.

13. The method according to claim 1, wherein: The first patterned material has a first volume. The first patterned material is deposited at a first location relative to the curved surface, and The method further includes: depositing a second patterned material having a second volume at a second location relative to the curved surface, wherein: The first thickness of the first patterned material at the first location corresponds to the thickness of the first volume, and The second thickness of the second patterned material at the second position corresponds to the thickness of the second volume.

14. The method according to claim 1, wherein: The first patterned material includes a first material, The first patterned material is deposited at a first location relative to the curved surface, and The method further includes: depositing a second patterned material comprising a second material at a second location relative to the curved surface, wherein: The first thickness of the first patterned material at the first location corresponds to the characteristics of the first material, and The second thickness of the second patterned material at the second position corresponds to the properties of the second material.

15. The method according to claim 1, wherein: The first patterned material is deposited at a plurality of first locations on the curved surface, the first locations being separated by a first interval. The cured patterned material also includes a second pattern, and The method further includes: depositing a second patterned material at a plurality of second locations on the curved surface, the second locations being separated by a second interval, wherein: The first interval corresponds to the first thickness for applying the first force to create the first pattern, and The second interval corresponds to the second thickness used to apply the second force for creating the second pattern.

16. The method according to claim 1, further comprising: The pattern is etched onto the curved surface.

17. An optical stack including optical features, wherein, The optical feature is formed using a method comprising the following steps: Deposit a first patterned material on a curved surface; The cover plate is positioned on the first patterned material, the cover plate including a template associated with the pattern, wherein the optical features include the pattern; A force is applied between the curved surface and the cover plate using the first patterned material, wherein the force includes capillary force, wherein the curved surface includes one or more nanochannel arrangements configured to increase the diffusion of the first patterned material on the curved surface to reduce the gap thickness occupied by the first patterned material and increase the capillary force between the curved surface and the cover plate. Curing the first patterned material, the curing resulting in a cured patterned material including the pattern; and Remove the cover plate.

18. A system for having a pattern on a curved surface, comprising: A wearable head device, the wearable head device including a display, wherein: The display includes an optical stack, the optical stack including optical features, and The optical feature is formed using a method comprising the following steps: A first patterned material is deposited on the curved surface; The cover plate is positioned on the first patterned material, the cover plate including a template associated with the pattern, wherein the optical features include the pattern; A force is applied between the curved surface and the cover plate using the first patterned material, wherein the force includes capillary force, wherein the curved surface includes one or more nanochannel arrangements configured to increase the diffusion of the first patterned material on the curved surface to reduce the gap thickness occupied by the first patterned material and increase the capillary force between the curved surface and the cover plate. Curing the first patterned material, the curing resulting in a cured patterned material including the pattern; and Remove the cover plate; and One or more processors are configured to perform a method including the following steps: Content associated with a mixed reality environment is presented on the display, wherein the content is presented based on the optical features.

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