An augmented reality display having a liquid crystal variable focusing element and a roll-to-roll method and apparatus for forming such a display

Abstract

A display device includes a waveguide assembly that includes a waveguide configured to couple light out of a main surface of the waveguide to form an image in a user's eye. The adaptive lens assembly has a main surface facing an output surface and a waveplate lens and a switchable waveplate assembly. The switchable waveplate assembly includes a quarter-wave plate on opposite sides of a switchable liquid crystal layer, and electrodes in a volume between the quarter-wave plates and on the quarter-wave plates. The electrodes can selectively establish an electric field and serve as an alignment structure for molecules of the liquid crystal layer. Portions of the adaptive lens assembly can be fabricated by roll-to-roll processing, where a substrate roll is unwound and an alignment layer and a liquid crystal layer are formed on the substrate as it moves toward a second roll to be wound on the second roll.

Description

[0001] Priority Benefit

[0002] This application claims priority benefit of U.S. Provisional Application No. 62 / 577,678, filed on Oct. 26, 2017, entitled “AUGMENTED REALITY DISPLAY HAVING LIQUID CRYSTAL VARIABLE FOCUS ELEMENT AND ROLL-TO-ROLL METHOD AND APPARATUS FOR FORMING THE SAME”, the entire content of which is incorporated herein by reference.

[0003] Incorporation by Reference

[0004] This application incorporates by reference in its entirety each of the following patent applications: U.S. Application No. 14 / 555,558, filed on Nov. 27, 2014, which was published as U.S. Publication No. 2015 / 0205126 on Jul. 23, 2015; U.S. Application No. 14 / 690,401, filed on Apr. 18, 2015, which was published as U.S. Publication No. 2015 / 0302652 on Oct. 22, 2015; U.S. Application No. 14 / 212,961, filed on Mar. 14, 2014, now U.S. Patent No. 9,417,452, issued on Aug. 16, 2016; U.S. Application No. 14 / 331,218, filed on Jul. 14, 2014, which was published as U.S. Publication No. 2015 / 0309263 on Oct. 29, 2015; U.S. Patent Application No. 15 / 683,706, filed on Aug. 22, 2017; U.S. Provisional Patent Application No. 62 / 424,341, filed on Nov. 18, 2016; U.S. Provisional Patent Application No. 62 / 518,539, filed on Jun. 12, 2017; and U.S. Patent No. 15 / 990,155, filed on May 25, 2018. Technical Field

[0005] This disclosure relates to display systems, and more particularly, to augmented reality display systems. Background Art

[0006] Modern computing and display technologies have facilitated the development of systems for so-called "virtual reality" or "augmented reality" experiences, in which digitally reproduced images or portions thereof are presented to a user in a manner that they appear real or can be perceived as real. A virtual reality or "VR" scenario typically involves the presentation of digital or virtual image information with no transparency to other actual real-world visual inputs; an augmented reality or "AR" scenario generally involves presenting digital or virtual image information as an enhancement to the visualization of the real world surrounding the user. A mixed reality or "MR" scenario is a type of AR scenario and generally involves virtual objects integrated into and responsive to the natural world. For example, in an MR scenario, AR image content can be blocked by objects in the real world or otherwise perceived as interacting with objects in the real world.

[0007] Reference Figure 1 , describes an augmented reality scenario 10, in which a user of AR technology sees a real-world park-like setting 20 characterized by people, trees, buildings in the background, and a concrete platform 30. In addition to these items, the user of AR technology also perceives that he "sees" "virtual content", such as a robotic figure 40 standing on the real-world platform 30, and a flying cartoon-like avatar character 50, which appears to be an anthropomorphic representation of a bumblebee, even though these elements 40, 50 do not exist in the real world. Because the human visual perception system is complex, it is challenging to produce AR technology that facilitates a comfortable, natural-feeling, rich presentation of virtual image elements with other virtual or real-world image elements.

[0008] The systems and methods disclosed herein address various challenges associated with AR and VR technologies. Summary of the Invention

[0009] Details of one or more implementations of the subject matter described in this specification are set forth in the accompanying drawings and the following description. Other features, aspects, and advantages will become apparent from the specification, the drawings, and the claims. This summary and the following detailed description are not intended to limit or restrict the scope of the subject matter of the present invention.

[0010] In a first embodiment, a display device is described. The display device includes: a waveguide assembly that includes a waveguide configured to output light to display an image; and an adaptive lens assembly having a main surface facing the main surface of the waveguide. The adaptive lens assembly includes a waveplate lens and a switchable waveplate assembly. The switchable waveplate assembly includes: a first non-liquid crystal quarter-wave plate and a second non-liquid crystal quarter-wave plate that define a volume therebetween; and a liquid crystal layer disposed in the volume between the first quarter-wave plate and the second quarter-wave plate, wherein the liquid crystal molecules of the liquid crystal layer have a selectively switchable orientation.

[0011] The switchable waveplate assembly may further include an electrode pattern disposed in the volume between the first quarter-waveplate and the second quarter-waveplate, the electrode pattern including a conductive material configured to selectively establish an electric field to change the orientation of liquid crystal molecules. The electrode pattern may be disposed on the first quarter-waveplate, and another electrode pattern may be disposed in the volume on the second quarter-waveplate. The waveplate lens may include a liquid crystal polymer layer. The adaptive lens assembly may further include an alignment layer disposed between the waveplate lens and the first quarter-waveplate, wherein the alignment layer at least partially determines the orientation of the liquid crystal molecules in the liquid crystal polymer layer. The waveplate lens may include another liquid crystal polymer layer on the liquid crystal polymer layer. The volume between the first quarter-waveplate and the second quarter-waveplate may be further defined by cell walls extending between the first quarter-waveplate and the second quarter-waveplate, wherein the cell walls include an inkjet-printable material. The waveplate lens and the switchable waveplate assembly may form an adaptive lens assembly, wherein the adaptive lens assembly includes a plurality of adaptive lens sub-assemblies, each adaptive lens sub-assembly including a waveplate lens and a switchable waveplate assembly. The display device may further include another adaptive lens assembly on the side of the waveguide assembly opposite the adaptive lens assembly, wherein the another adaptive lens assembly includes an associated waveplate lens and an associated switchable waveplate assembly.

[0012] In another embodiment, an adaptive lens assembly is described. The adaptive lens assembly includes a waveplate lens and a switchable waveplate assembly. The switchable waveplate assembly includes: a first non-liquid-crystal quarter-waveplate and a second non-liquid-crystal quarter-waveplate that define a volume therebetween; and a liquid crystal layer disposed in the volume between the first quarter-waveplate and the second quarter-waveplate, wherein the liquid crystal molecules of the liquid crystal layer have a selectively switchable orientation.

[0013] The switchable waveplate assembly may further include: an electrode pattern disposed in the volume between the first quarter-waveplate and the second quarter-waveplate, the electrode pattern including a conductive material configured to selectively establish an electric field to change the orientation of liquid crystal molecules. The electrode pattern may be disposed on the first quarter-waveplate, and another electrode pattern may be disposed in the volume on the second quarter-waveplate. The waveplate lens may include a liquid crystal polymer layer. The adaptive lens assembly may further include an alignment layer disposed between the waveplate lens and the first quarter-waveplate, wherein the alignment layer at least partially determines the orientation of the liquid crystal molecules in the liquid crystal polymer layer. The waveplate lens may include another liquid crystal polymer layer on the liquid crystal polymer layer. The volume between the first quarter-waveplate and the second quarter-waveplate may be further defined by a cell wall extending between the first quarter-waveplate and the second quarter-waveplate, wherein the cell wall includes an inkjet-printable material. The waveplate lens and the switchable waveplate assembly may form an adaptive lens subassembly, wherein the adaptive lens assembly includes a plurality of adaptive lens subassemblies, each adaptive lens subassembly including a waveplate lens and a switchable waveplate assembly.

[0014] In another example, a display device is described. The display device includes: a waveguide assembly including a waveguide configured to output light to display an image; and an adaptive lens assembly having a main surface facing the main surface of the waveguide. The adaptive lens assembly includes a waveplate lens and a switchable waveplate assembly. The switchable waveplate assembly includes: a first substrate and a second substrate defining a volume therebetween; a liquid crystal layer disposed in the volume; a first set of guides for aligning the liquid crystal molecules of the liquid crystal layer, the first set of guides including a first electrode pattern disposed in the volume and on the first substrate; and a second set of guides for aligning the liquid crystal molecules of the liquid crystal layer, the second set of guides including a second electrode pattern disposed in the volume and on the first substrate. The first electrode pattern and the second electrode pattern are configured to establish an electric field for selectively changing the orientation of the liquid crystal molecules of the liquid crystal layer.

[0015] At least one of the first electrode pattern and the second electrode pattern may include an array of parallel conductors. At least one of the first electrode pattern and the second electrode pattern may include a wire mesh. Each of the first substrate and the second substrate may include a quarter-waveplate. The waveplate lens and the switchable waveplate assembly may form an adaptive lens subassembly, wherein the adaptive lens assembly includes a plurality of adaptive lens subassemblies, each adaptive lens subassembly including a waveplate lens and a switchable waveplate assembly. The display device may further include another adaptive lens assembly on a side of the waveguide assembly opposite the adaptive lens assembly, wherein the another adaptive lens assembly includes an associated waveplate lens and an associated switchable waveplate assembly.

[0016] In another embodiment, an adaptive lens assembly is described. The adaptive lens assembly includes a waveplate lens and a switchable waveplate assembly. The switchable waveplate assembly includes: a first substrate and a second substrate that define a volume therebetween; a liquid crystal layer within the volume; a first set of guides for aligning the liquid crystal molecules of the liquid crystal layer, the first set of guides including a first electrode pattern disposed in the volume and on the first substrate; a second set of guides for aligning the liquid crystal molecules of the liquid crystal layer, the second set of guides including a second electrode pattern disposed in the volume and on the first substrate. The first electrode pattern and the second electrode pattern are configured to establish an electric field for selectively changing the orientation of the liquid crystal molecules of the liquid crystal layer.

[0017] At least one of the first electrode pattern and the second electrode pattern may include an array of parallel conductors. At least one of the first electrode pattern and the second electrode pattern may include a wiring screen. Each of the first substrate and the second substrate may include a quarter-wave plate. The waveplate lens may include a liquid crystal polymer layer. The adaptive lens assembly may further include an alignment layer disposed between the waveplate lens and the first quarter-wave plate, wherein the alignment layer at least partially determines the orientation of the liquid crystal molecules in the liquid crystal polymer layer. The waveplate lens may include another liquid crystal polymer layer on the liquid crystal polymer layer. The waveplate lens and the switchable waveplate assembly may form an adaptive lens subassembly, wherein the adaptive lens assembly includes a plurality of adaptive lens subassemblies, each adaptive lens subassembly including a waveplate lens and a switchable waveplate assembly.

[0018] In another embodiment, a roll-to-roll apparatus for manufacturing a liquid crystal lens is described. The apparatus includes: a supply substrate roll for providing a roll of substrates for processing; a lens substrate roll for receiving the processed substrates having lens structures thereon; a substrate path that defines a path for the unwound substrates from the supply substrate roll to the lens substrate roll; an alignment structure applicator in the substrate path and configured to form an alignment structure for guiding the orientation of liquid crystal molecules on a first side of the substrate; and a first lens layer applicator in the substrate path and including a slot die configured to apply a first liquid crystal layer to the first side of the supply substrate and a first curing station configured to cure the first liquid crystal layer.

[0019] The first curing station may include an ultraviolet (UV) light source configured to polymerize the liquid crystal molecules of the first liquid crystal layer. The first curing station may include a heat source configured to heat the first liquid crystal layer. The roll-to-roll apparatus may further include a second lens layer applicator including a slot die configured to apply a second liquid crystal layer over the cured first lens layer and a second curing station configured to cure the second liquid crystal layer. The second curing station may include an ultraviolet (UV) light source configured to polymerize the liquid crystal molecules of the second liquid crystal layer. The second curing station may include a heat source configured to heat the second liquid crystal layer. The alignment structure applicator may include: a slot die configured to apply an alignment layer resist material to a first side of a supply substrate; a curing station configured to cure the alignment layer resist material to form a solid alignment layer; and an optical aligner configured to optically pattern one or more alignment structures within the solid alignment layer. The alignment structure applicator may include: an inkjet printer configured to print a liquid resist material onto a first side of a supply substrate; a conformal roll template configured to imprint the liquid resist material to form a liquid crystal alignment structure; and an energy source configured to cure the liquid resist material while the liquid resist material is in contact with the conformal roll template to form a solid resist forming a pattern including the alignment structure on the first side of the supply substrate.

[0020] In another embodiment, a roll-to-roll apparatus for manufacturing a liquid crystal lens is described. The apparatus includes: a supply substrate roll for providing a roll of substrates for processing; an intermediate substrate roll for receiving the processed substrates having alignment structures thereon; a substrate path defining a path for the unwound substrate from the supply substrate roll to the intermediate substrate roll; a deposition device configured to deposit an imprint resist; a continuous template ring configured to travel along a closed template path defined by a plurality of rolls, wherein an imprint portion of the template path coincides with a portion of the substrate path; and an energy source configured to cure the alignment structure to form a solid alignment layer.

[0021] The energy source may include an ultraviolet (UV) light source. The deposition device may include a slot die upstream of the energy source configured to apply the imprint resist to a first side of the supply substrate, and the template ring may be configured to imprint the imprint resist along the imprint portion of the roll template path. The deposition device may include an inkjet printer upstream of the energy source, the inkjet printer may be configured to print the imprint resist, and the template is configured to imprint the imprint resist along the imprint portion of the template path. The inkjet printer may be configured to deposit the imprint resist onto the template.

[0022] In another example, a method for manufacturing a liquid crystal lens is described. The method includes: unwinding a supply roll of a substrate at a supply substrate roll; processing the unwound substrate that extends between the supply substrate roll and a lens substrate roll; and subsequently rewinding the unwound substrate at the lens substrate roll, wherein processing the unwound substrate includes forming an alignment layer on a first side of the unwound substrate, depositing a first liquid crystal layer over the alignment structure, and curing the first liquid crystal layer to form a first lens layer.

[0023] Depositing the first liquid crystal layer may include applying the liquid crystal onto the alignment structure using a slot die. Curing the first liquid crystal layer may include irradiating the first liquid crystal layer with ultraviolet (UV) light. Curing the first liquid crystal layer may include heating the first liquid crystal layer in an oven. Forming the alignment layer may include depositing a selectively definable material onto the first side of the substrate and patterning the deposited selectively definable material. Patterning the selectively definable material may include exposing the selectively definable material to light to form a holographic record. The selectively definable material may be a resist, wherein patterning the selectively definable material includes imprinting the resist using a conformal roll template; and curing the liquid resist material when the liquid resist material is in contact with the conformal roll template to form a solid alignment structure on the first side of the supply substrate. The method may further include applying a second liquid crystal layer over the first lens layer and curing the second liquid crystal layer to form a solid second lens layer. The method may further include forming an electrode pattern on a lower side of the substrate opposite the side on which the alignment layer is formed before unwinding the supply roll. The method may further include, after rewinding the unwound substrate, unwinding the substrate and forming a plurality of liquid crystal cell walls on the lower side of the substrate. Forming the plurality of liquid crystal cell walls may include inkjet deposition. The method may further include attaching the substrate to another substrate to form an open volume defined by the substrate and the other substrate and the liquid crystal cell walls, and filling the open volume with a liquid crystal. The substrate may be a quarter-wave plate.

[0024] In another embodiment, a method for manufacturing a liquid crystal lens is described. The method includes unwinding a supply roll of a substrate at a supply substrate roll, wherein the unwound substrate extends between the supply substrate roll and an intermediate substrate roll; forming alignment features on the unwound substrate for guiding the orientation of liquid crystal molecules on the substrate, wherein forming the alignment features includes imprinting the alignment features using a closed-loop template having a travel path defined by a plurality of rolls; and subsequently rewinding the unwound substrate at the intermediate substrate roll.

[0025] Forming the alignment features may include depositing an imprint resist on a substrate, imprinting the imprint resist using a template, and curing the imprint resist while imprinting the imprint resist using the template to form a solid-state alignment structure on the supply substrate. The supply roller may include an electrode pattern on a lower side of the substrate opposite an upper side on which the alignment layer is to be formed. The method may further include, after re-rolling the unwound substrate, unwinding the substrate and forming a plurality of liquid crystal cell walls on the upper side of the substrate. Forming the plurality of liquid crystal cell walls may include printing the cell walls by inkjet deposition. The method may further include attaching the substrate to another substrate to form an open volume defined by the substrate, the another substrate, and the liquid crystal cell walls, and filling the open volume with a liquid crystal. The substrate may be a quarter-wave plate.

[0026] In another example, a method for manufacturing a liquid crystal lens is described. The method includes: unwinding a roll of an intermediate substrate at an intermediate substrate roller, the intermediate substrate including alignment features for liquid crystal molecules on a first side of the intermediate substrate; processing the unwound substrate extending between the intermediate substrate roller and a lens substrate roller; and subsequently re-rolling the unwound substrate at the lens substrate roller. Processing the unwound substrate includes depositing a first liquid crystal layer on the alignment features and curing the first liquid crystal layer to form a first lens layer.

[0027] Depositing the first liquid crystal layer may include applying a liquid crystal material using a slot die. Curing the first liquid crystal layer may include irradiating the first liquid crystal layer with ultraviolet (UV) light. Curing the first liquid crystal layer may include heating the first liquid crystal layer in an oven. The method may further include applying a second liquid crystal layer over the first lens layer and curing the second liquid crystal layer to form a solid-state second lens layer. The method may further include, after re-rolling the unwound substrate, unwinding the substrate and forming a plurality of liquid crystal cell walls on the substrate. Forming the plurality of liquid crystal cell walls may include inkjet deposition. The method may further include attaching the substrate to another substrate to form an open volume defined by the substrate, the another substrate, and the liquid crystal cell walls, and filling the open volume with a liquid crystal material. The substrate may be a quarter-wave plate including alignment features thereon. Description of the Drawings

[0028] Figure 1 A view of augmented reality (AR) of a user through an AR device is shown.

[0029] Figure 2 A conventional display system for a simulated three-dimensional image for a user is shown.

[0030] Figures 3A - 3C The relationship between the radius of curvature and the focal radius is shown.

[0031] Figure 4A A representation of the accommodation-vergence response of the human visual system is shown.

[0032] Figure 4B Examples of different accommodation states and convergence states of a pair of eyes of a user are shown.

[0033] Figure 4C An example of a representation of a top view of a user viewing content via a display system is shown.

[0034] Figure 4D Another example of a representation of a top view of a user viewing content via a display system is shown.

[0035] Figure 5 Aspects of a method for simulating three-dimensional images by modifying wavefront divergence are shown.

[0036] Figure 6 An example of a waveguide stack for outputting image information to a user is shown.

[0037] Figure 7 An example of an outgoing light beam output from a waveguide is shown.

[0038] Figure 8 An example of a stacked waveguide assembly is shown, where each depth plane includes an image formed using multiple different component colors.

[0039] Figure 9A A cross-sectional side view of an example of a stacked waveguide group is shown, each stacked waveguide including an optical element coupled therein.

[0040] Figure 9B Shows Figure 9A A perspective view of an example of multiple stacked waveguides.

[0041] Figure 9C Shows Figure 9A And 9B A top plan view of an example of multiple stacked waveguides.

[0042] Figure 9D An example of a wearable display system is shown.

[0043] Figure 10 An example of a display system including a pair of adaptive lens assemblies is shown.

[0044] Figure 11A Shows Figure 10 An example of a display system that displays virtual content to a user at a virtual depth plane.

[0045] Figure 11B Shows Figure 10 An example of a display system that provides a view of real-world content to a user.

[0046] Figure 12 An example of a display device including a pair of adaptive lens assemblies is shown, each adaptive lens assembly including a waveplate lens and a switchable waveplate stacked alternately.

[0047] Figure 13A and 13B An example of a display device including a pair of adaptive lens assemblies and a pair of fixed lenses is shown.

[0048] Figure 14 An example of a display device including a pair of adaptive lens assemblies and a fixed lens is shown.

[0049] Figure 15 An example of an adaptive lens assembly including three adaptive lens layers is shown.

[0050] Figure 16A and 16B Another example of an adaptive lens assembly is shown, each including three adaptive lens layers.

[0051] Figures 17A - 17E An example of a process for manufacturing an adaptive lens assembly is shown.

[0052] Figure 18A An example of an apparatus for roll-to-roll manufacturing of a lens substrate using an optical alignment process for an adaptive lens assembly is shown.

[0053] Figure 18B -C shows an example of an apparatus for roll-to-roll manufacturing of a lens substrate using an imprint alignment process for an adaptive lens assembly.

[0054] Figure 18D An example of an apparatus for roll-to-roll manufacturing of an intermediate substrate using an imprint alignment process for an adaptive lens assembly is shown.

[0055] Figure 18E shows an example of an apparatus for roll-to-roll manufacturing of a lens substrate using an intermediate substrate produced by Figure 18D the apparatus.

[0056] Figure 19A An example of an apparatus for sheet manufacturing of a lens substrate using an imprint alignment process for an adaptive lens assembly is shown.

[0057] Figure 19B An example of an apparatus for plate manufacturing of a lens substrate using an optical alignment process for an adaptive lens assembly is shown.

[0058] Figure 20A An example of an apparatus for spin coating manufacturing of a lens substrate using an imprint alignment process for an adaptive lens assembly is shown.

[0059] Figure 20B An example device for spin coating a lens substrate using an optical alignment process for an adaptive lens assembly is shown.

[0060] Figures 21A - 21C An example of a process for forming a pattern of a conductive material by directional etching is shown.

[0061] Figures 22A - 22C An example of a process for forming a pattern of a conductive material using a solvent - soluble layer is shown.

[0062] Figures 23A - 23C An example of a process for forming a pattern of a conductive material using a seed layer is shown.

[0063] Figures 24A - 24C Another example of a process for forming a pattern of a conductive material using a seed layer is shown.

[0064] Figures 25A - 25C An example of a process for forming a pattern of a conductive material by depositing a suspension of a metal material into openings in a patterned layer is shown.

[0065] Figures 26A - 26F An example of a top - view of a pattern of a conductive material is shown.

[0066] Figures 27A - 27D An example of a cross - sectional side - view of a conductive material line is shown. Detailed Description

[0067] An AR system can display virtual content to a user or observer while still allowing the user to see the world around them. Preferably, the content is displayed on a head - mounted display (e.g., as part of glasses) that projects image information onto the user's eyes. Additionally, the display can also transmit light from the surrounding environment to the user's eyes to allow a view of the surrounding environment. As used herein, it will be understood that a "head - mounted" or "head - mountable" display is a display that can be mounted on the head of an observer or user.

[0068] In some AR systems, multiple waveguides can be configured to form virtual images at multiple virtual depth planes (also simply referred to herein as "depth planes"). Different waveguides among the multiple waveguides can have different optical powers, which can provide images on different depth planes that appear to be at different distances from the user's eyes. The display system can also include multiple lenses that provide optical power or modify the optical power of the waveguides. Unfortunately, each of the waveguides and lenses can increase the overall thickness and weight of the display.

[0069] In methods for reducing the thickness and weight of a display, adaptive lens assemblies have been proposed, which may also be referred to as variable focus lens assemblies. The adaptive lens assembly provides a variable optical power to, for example, modify the wavefront divergence of light propagating through the lens assembly to provide a plurality of different virtual depth planes. For example, instead of a plurality of waveguides, a single adaptive lens assembly can be utilized to provide a set of different optical powers and associated depth planes. Examples of adaptive lens assemblies and related structures are disclosed in U.S. Provisional Patent Application No. 62 / 424,341 filed on November 18, 2016 and U.S. Provisional Patent Application No. 62 / 518,539 filed on June 12, 2017, the entire disclosures of which are hereby incorporated by reference herein.

[0070] The adaptive lens assembly can include a stack of adaptive lens sub-assemblies, each of the adaptive lens sub-assemblies can include a waveplate lens and a switchable waveplate assembly, the switchable waveplate assembly can include a liquid crystal layer having liquid crystal molecules that can be switched between different states having different orientations. The switchable waveplate assembly can include: a pair of substrates for confining the liquid crystal layer; an alignment layer for establishing the orientation of the liquid crystal molecules in the liquid crystal layer; and a conductive layer for providing an electric field to switch the orientation of the liquid crystal molecules. It will be understood that each adaptive lens sub-assembly can differently affect the wavefront of the passing light depending on the state of the switchable waveplate. The optical powers of the plurality of sub-assemblies can be combined to provide different total optical powers. However, it has been found that an adaptive lens assembly having a large number of such sub-assemblies may still be thicker than desired.

[0071] Advantageously, in some embodiments, a thin adaptive lens assembly and methods and apparatuses for manufacturing such an assembly are provided. In some embodiments, the switchable waveplate assembly can include a pair of substrates that are themselves waveplates (e.g., quarter-wave plates), and a switchable waveplate (preferably, a liquid crystal layer having liquid crystal molecules with selectively switchable orientations) is disposed therebetween. Preferably, the substrates do not contain liquid crystal. In some other embodiments, the switchable waveplate assembly can include a pattern of electrodes that serves both as an alignment guide for the liquid crystal molecules and as a conductive layer for selectively establishing an electric field for switching the orientation of the liquid crystal molecules. In some embodiments, the electrode pattern can be disposed on the surface of a substrate that also serves as a waveplate. For example, the electrodes can be disposed on opposite faces of the substrate and in the same volume occupied by the liquid crystal layer between the substrates. It will be understood that the electrodes can be freely placed on the surface of the substrate or can be embedded in other material layers.

[0072] Advantageously, the thin switchable waveplate assembly can form an adaptive lens subassembly with a passive waveplate lens that does not include liquid crystal molecules whose orientation changes with the application of the above-mentioned electric field. It will be understood that the switchable waveplate assembly and the passive waveplate lens can change the polarization of light and thereby provide optical power. The passive waveplate lens can be formed from polymeric liquid crystal molecules that have been locked into a specific pattern and / or orientation. The specific pattern and / or orientation can provide a desired optical response only within a narrow wavelength range of light. In some embodiments, to provide a more broadband response over a wider wavelength range, multiple waveplate lenses can be provided. Each of the waveplate lenses can have a peak response within a different wavelength range, and overall, the waveplate lenses provide a response over a wider wavelength range.

[0073] As described herein, multiple subassemblies can be stacked together to form an adaptive lens assembly that provides a range of optical powers. In some other embodiments, the adaptive lens assembly can include only a single subassembly.

[0074] In some embodiments, roll-to-roll manufacturing equipment can be used to manufacture the adaptive lens assembly or portions thereof. A substrate that forms part of the volume containing the switchable liquid crystal layer can be used as the substrate on which adjacent layers are formed, and then a pair of substrates can be placed together to form the volume that is subsequently filled with the switchable liquid crystal. The substrate is preferably formed from a flexible, mechanically stable, optically transmissive material that can be rolled up and unrolled during the manufacturing process. For example, a supply of the substrate can be provided on a first roller and extended to a second roller. The substrate is unrolled on the first roller and then re-rolled on the second roller. In between, an alignment layer can be deposited and patterned on the substrate, and one or more liquid crystal layers can be deposited and cured on the alignment layer. Preferably, the substrate supplied on the first roller can include a previously formed electrode pattern on the back side of the substrate.

[0075] In some embodiments, a first roll-to-roll device can be used for the manufacture of the alignment layer, where the substrate roll is unrolled and an imprinted alignment layer (including alignment features for the liquid crystal molecules) is formed on the substrate, and after the imprinted alignment layer is formed, the substrate roll is re-rolled. Subsequently, a second roll-to-roll manufacturing device uses the substrate having the imprinted alignment layer including alignment features as a starting material, deposits the liquid crystal layer on the substrate, and then re-rolls the substrate having the deposited liquid crystal layer.

[0076] In some embodiments, after roll-to-roll processing, a processed substrate sheet having electrodes on one side and a deposited layer on the opposite side of the sheet may be joined to another substrate sheet having electrodes on the surface of another sheet. Before joining the substrate sheets together, walls may be formed on one or both sheets to laterally confine the subsequent liquid crystal filling. The walls may be of a shape required for the display eyepiece. The sheets may then be joined together with the electrodes facing each other to form an open volume. This open volume is subsequently filled with liquid crystal, and then the sheets may be cut to form individual display eyepieces. In some other embodiments, liquid crystal may be provided in the volume defined by the walls and the underlying substrate, and then the overlying substrate may be adhered to the walls to form a closed volume.

[0077] Advantageously, in some embodiments, the adaptive lens assemblies described herein may be thin and / or lightweight structures. For example, an adaptive lens assembly having three adaptive lens sub-assemblies may have a relatively small thickness (e.g., less than 2 mm in some embodiments). By using the quarter-wave plate both as an optical element within the adaptive lens sub-assembly and as a support substrate, an additional support substrate may not be required. Further, a wiring mesh or wiring array on the surface of the quarter-wave plate adjacent to the liquid crystal layer may be arranged to serve both as a source of electric potential and as an alignment structure for guiding the alignment of liquid crystal molecules in the liquid crystal layer. Additionally, the disclosed roll-to-roll manufacturing apparatus and method allow for the efficient, high-volume manufacture of adaptive lens assemblies.

[0078] Reference will now be made to the drawings, where like reference numerals refer to like components throughout. Unless otherwise noted, the drawings are schematic and not necessarily drawn to scale.

[0079] Figure 2 A conventional display system for simulating three-dimensional images for a user is shown. It will be understood that a user's eyes are separated, and when viewing a real object in space, each eye will have a slightly different view of the object, and an image of the object may be formed at different locations on the retina of each eye. This may be referred to as binocular parallax and may be utilized by the human visual system to provide depth perception. The conventional display system simulates binocular parallax by presenting two different images 190, 200 having slightly different views of the same virtual object (one for each eye 210, 220), the different views corresponding to the views of the virtual object that each eye would see, the virtual object being a virtual object of a real object located at a desired depth. These images provide binocular cues, which the user's visual system may interpret to obtain depth perception.

[0080] Continuing to refer Figure 2, Images 190, 200 are separated from eyes 210, 220 by a distance 230 on the z-axis. The z-axis is parallel to the observer's optical axis, and their eyes are focused on an object at optical infinity directly in front of the observer. Images 190, 200 are flat and at a fixed distance from eyes 210, 220. Based on slightly different views of a virtual object in the images presented to eyes 210, 220 respectively, the eyes can rotate naturally so that the images of the object fall on corresponding points on the retina of each eye to maintain single binocular vision. This rotation can cause the lines of sight of each eye 210, 220 to converge to a point in the space where the virtual object is perceived to exist. As a result, providing a three-dimensional image generally involves providing binocular cues that can manipulate the convergence of the user's eyes 210, 220, and the human visual system interprets these binocular cues to provide depth perception.

[0081] However, generating a realistic and comfortable depth perception is challenging. It will be understood that light from objects at different distances from the eyes has wavefronts with different amounts of divergence. Figures 3A - 3C Shows the relationship between distance and the divergence of light rays. The distances between the object and eye 210 are represented by R1, R2, and R3 in decreasing order of distance. As shown in Figures 3A - 3C , when the distance to the object decreases, the light rays become more divergent. Conversely, when the distance increases, the light rays become more collimated. In other words, it can be said that the light field generated by a point (the object or a part of the object) has a spherical wavefront curvature that is a function of how far the point is from the user's eyes. The curvature increases as the distance between the object and eye 210 decreases. Although for clarity of illustration only a single eye 210 is shown in Figures 3A - 3C and other figures in this document, the discussion regarding eye 210 can apply to both eyes 210 and 220 of the observer.

[0082] Continuing to refer to Figures 3A - 3C, the light from an object that is being looked at by an observer's eye can have different degrees of wavefront divergence. Due to the different amounts of wavefront divergence, the light can be focused differently by the eye's lens, which in turn may require the lens to assume different shapes to form a focused image on the retina of the eye. In the case where a focused image is not formed on the retina, the resulting retinal blur serves as a cue for accommodation, which causes a change in the shape of the eye's lens until a focused image is formed on the retina. For example, the cue for accommodation can trigger the relaxation or contraction of the ciliary muscles surrounding the eye lens, thereby adjusting the force applied to the zonular ligaments that hold the lens, and thus causing the shape of the eye lens to change until the retinal blur of the object being looked at is eliminated or minimized, thereby forming a focused image of the object being looked at on the retina (e.g., fovea) of the eye. The process by which the shape of the eye lens changes can be referred to as accommodation, and the shape of the eye lens required to form a focused image of the object being looked at on the retina (e.g., fovea) of the eye can be referred to as the accommodative state.

[0083] Now refer to Figure 4A , which shows a representation of the accommodation-convergence response of the human visual system. Eye movements are made to look at an object such that the eyes receive light from the object, where the light forms an image on each of the retinas of the eyes. The presence of retinal blur in the images formed on the retinas can provide a cue for accommodation, and the relative positions of the images on the retinas can provide a cue for convergence. The cue for accommodation causes accommodation to occur, resulting in each of the eye lenses assuming a particular accommodative state, which forms a focused image of the object on the retina (e.g., fovea) of the eye. On the other hand, the cue for convergence causes a convergence movement (rotation of the eyes) to occur such that the images formed on each retina of each eye are at corresponding retinal points that maintain single binocular vision. At these positions, it can be said that the eyes are in a particular convergence state. Continuing to refer to Figure 4A , accommodation can be understood as the process by which the eyes achieve a particular accommodative state, and convergence can be understood as the process by which the eyes achieve a particular convergence state. As Figure 4A shown, if the user looks at another object, the accommodative and convergence states of the eyes can change. For example, if the user looks at a new object at a different depth along the z-axis, the accommodative state can change.

[0084] Without being limited by theory, it is believed that an observer of an object can perceive the object as "three-dimensional" due to a combination of convergence and accommodation. As described above, the convergence movement of the two eyes relative to each other (e.g., the rotation of the eyes such that the pupils move towards or away from each other to converge the lines of sight of the eyes to fixate on an object) is closely related to the accommodation of the lenses of the eyes. Under normal circumstances, changing the shape of the lens of the eye to change the focus from one object to another object located at a different distance will automatically cause a matching change in convergence to the same distance in a relationship called the "accommodation-convergence reflex". Similarly, under normal circumstances, a change in convergence will trigger a matching change in the shape of the lens.

[0085] Now referring to Figure 4B , an example of different accommodation and convergence states of the eyes is shown. The eye pair 222a is fixated on an object at optical infinity, while the eye pair 222b is fixated on an object 221 that is less than optically infinite. It is noted that the convergence states of each eye pair are different, where the eye pair 222a is pointed straight ahead, while the eye pair 222 converges on the object 221. The accommodation states of the eyes forming each eye pair 222a and 222b can also be different, as indicated by the different shapes of the lenses 210a, 220a.

[0086] Unfortunately, many users of conventional "3-D" display systems find these conventional systems uncomfortable or do not perceive a sense of depth at all due to the mismatch between the accommodation and convergence states in these displays. As described above, many stereoscopic or "3-D" display systems display a scene by providing slightly different images to each eye. Such systems are uncomfortable for many observers because they provide only different renderings of the scene among other things and cause a change in the convergence state of the eyes, but without a corresponding change in the accommodation state of those eyes. However, the images are shown by a display at a fixed distance from the eyes such that the eyes view all image information in a single accommodation state. This arrangement violates the "accommodation-convergence reflex" by causing a change in the convergence state without a matching change in the accommodation state. This mismatch is thought to cause discomfort to the observer. A display system that provides a better match between accommodation and convergence can form a more realistic and comfortable three-dimensional image simulation.

[0087] Without being limited by theory, it is believed that the human eye can typically interpret a limited number of depth planes to provide depth perception. Therefore, by providing different renderings of images corresponding to each of these limited number of depth planes to the eyes, a highly believable simulation of perceived depth can be achieved. In some embodiments, the different renderings can provide cues for convergence and matching cues for accommodation, thus providing a physiologically correct accommodation-convergence match.

[0088] Continuing to refer to Figure 4B, shows two depth planes 240, which correspond to different distances from the eyes 210, 220 in space. For a given depth plane 240, convergence cues can be provided by displaying appropriately different perspective images for each eye 210, 220. Additionally, for a given depth plane 240, the light forming the images provided to each eye 210, 220 can have a wavefront divergence corresponding to the light field generated by points at the distance of that depth plane 240.

[0089] In the illustrated embodiment, the distance of the depth plane 240 containing the point 221 along the z-axis is 1 m. As used herein, the distance or depth along the z-axis can be measured by a zero point located at the exit pupil of the user's eye. Thus, on the optical axis of those eyes that are pointed at optical infinity, the depth plane 240 located at a depth of 1 m corresponds to a distance of 1 m from the exit pupil of the user's eye. As an approximation, the depth or distance along the z-axis can be measured from a display in front of the user's eyes (e.g., from the surface of the waveguide), plus the value of the distance between the device and the exit pupil of the user's eye. This value can be referred to as eye relief and corresponds to the distance between the exit pupil of the user's eye and the display worn by the user in front of the eyes. In practice, the value of the eye relief can be a standardized value commonly used for all observers. For example, it can be assumed that the eye relief is 20 mm, and the depth plane at a depth of 1 m can be at a distance of 980 mm in front of the display.

[0090] Now refer to Figure 4C and 4D , which respectively show examples of a matched accommodation-convergence distance and a mismatched accommodation-convergence distance. As Figure 4C shown, the display system can provide images of virtual objects to each eye 210, 220. The images can cause the eyes 210, 220 to assume a convergence state where the eyes converge on the point 15 on the depth plane 240. Additionally, the images can be formed by light having a wavefront curvature corresponding to a real object at that depth plane 240. As a result, the eyes 210, 220 assume an accommodation state where the images are in focus on the retinas of those eyes. Thus, the user can perceive the virtual object at the point 15 on the depth plane 240.

[0091] It will be understood that each of the accommodation and convergence states of the eyes 210, 220 is associated with a specific distance on the z-axis. For example, an object at a specific distance from the eyes 210, 220 causes those eyes to assume a specific accommodation state based on the distance of the object. The distance associated with a specific accommodation state can be referred to as the accommodation distance A d . Similarly, there is a specific convergence distance V dWhen the accommodation distance and the vergence distance match, it can be said that the relationship between accommodation and vergence is physiologically correct. This is considered the most comfortable scenario for the viewer.

[0092] However, in a stereoscopic display, the accommodation distance and the vergence distance may not always match. For example, as Figure 4D shown, the images presented to eyes 210, 220 can be presented with a wavefront divergence corresponding to depth plane 240, and eyes 210, 220 can be in a specific accommodation state focused on points 15a, 15b on that depth plane. However, the images presented to eyes 210, 220 may provide a cue for vergence that causes eyes 210, 220 to converge at point 15 that is not located on depth plane 240. As a result, in some embodiments, the accommodation distance corresponds to the distance from the exit pupils of eyes 210, 220 to depth plane 240, while the vergence distance corresponds to a greater distance from the exit pupils of eyes 210, 220 to point 15. The accommodation distance is different from the vergence distance. Thus, there is an accommodation-vergence mismatch. This mismatch is considered undesirable and may cause discomfort to the user. It will be understood that the mismatch corresponds to a distance (e.g., V d -A d ) and can be characterized using diopters.

[0093] In some embodiments, it will be understood that a reference point other than the exit pupils of eyes 210, 220 can be used to determine the distances for determining the accommodation-vergence mismatch, as long as the same reference point is used for both the accommodation distance and the vergence distance. For example, the distance can be measured from the cornea to the depth plane, from the retina to the depth plane, from the eyepiece (e.g., the waveguide of the display device) to the depth plane, etc.

[0094] Without being limited by theory, it is believed that users can still perceive accommodation-vergence mismatches of up to about 0.25 diopters, up to about 0.33 diopters, and up to about 0.5 diopters as being physiologically correct, without significant discomfort caused by the mismatch itself. In some embodiments, the display system (e.g., Figure 6 display system 250) disclosed herein presents an image having an accommodation-vergence mismatch of about 0.5 diopters or less to an observer. In some other embodiments, the accommodation-vergence mismatch of the image provided by the display system is about 0.33 diopters or less. In other embodiments, the accommodation-vergence mismatch of the image provided by the display system is about 0.25 diopters or less, including about 0.1 diopters or less.

[0095] Figure 5Aspects of a method for simulating a three-dimensional image by modifying wavefront divergence are shown. The display system includes a waveguide 270 configured to receive light 770 encoded with image information and output the light to a user's eye 210. The waveguide 270 can output light 650 having a limited amount of wavefront divergence corresponding to the wavefront divergence of the light field generated by points on a desired depth plane 240. In some embodiments, the same amount of wavefront divergence is provided for all objects presented on the depth plane. Additionally, it will be described that image information from a similar waveguide can be provided to the user's other eye.

[0096] In some embodiments, a single waveguide can be configured to output light with a set amount of wavefront divergence corresponding to a single or a limited number of depth planes and / or the waveguide can be configured to output light within a limited wavelength range. Thus, in some embodiments, multiple waveguides or a waveguide stack can be utilized to provide different amounts of wavefront divergence for different depth planes and / or output light with different wavelength ranges. As used herein, it will be understood that at a depth plane, the contour of a flat or curved surface can be followed. In some embodiments, for simplicity, advantageously, the depth plane can follow the contour of a flat surface.

[0097] Figure 6 An example of a waveguide stack for outputting image information to a user is shown. The display system 250 includes a stack of waveguides or a stacked waveguide assembly 260 that can be used to provide a three-dimensional perception to the eye / brain using multiple waveguides 270, 280, 290, 300, 310. It will be understood that in some embodiments, the display system 250 can be considered a light field display. Additionally, the waveguide assembly 260 can also be referred to as an eyepiece.

[0098] In some embodiments, the display system 250 can be configured to provide substantially continuous cues regarding convergence and multiple discrete cues regarding accommodation. Cues regarding convergence can be provided by displaying different images to each of the user's eyes, and cues regarding accommodation can be provided by outputting the light forming the image with a selectable discrete amount of wavefront divergence. In other words, the display system 250 can be configured to output light with a variable level of wavefront divergence. In some embodiments, each discrete level of wavefront divergence corresponds to a particular depth plane and can be provided by a particular one of the waveguides 270, 280, 290, 300, 310.

[0099] Continuing to refer to Figure 6, the waveguide assembly 260 may also include a plurality of features 320, 330, 340, 350 between waveguides. In some embodiments, the features 320, 330, 340, 350 may be one or more lenses. The waveguides 270, 280, 290, 300, 310 and / or the plurality of lenses 320, 330, 340, 350 may be configured to send image information to the eye with different levels of wavefront curvature or light divergence. Each waveguide level may be associated with a particular depth plane and may be configured to output image information corresponding to that depth plane. The image injection devices 360, 370, 380, 390, 400 may act as light sources for the waveguides and may be used to inject image information into the waveguides 270, 280, 290, 300, 310, as described herein, where each of the waveguides may be configured to distribute incident light across each corresponding waveguide for output toward the eye 210. Light leaves the output surfaces 410, 420, 430, 440, 450 of the image injection devices 360, 370, 380, 390, 400 and is injected into the corresponding input surfaces 460, 470, 480, 490, 500 of the waveguides 270, 280, 290, 300, 310. In some embodiments, each of the input surfaces 460, 470, 480, 490, 500 may be an edge of the corresponding waveguide or may be a portion of the major surface of the corresponding waveguide (i.e., one of the waveguide surfaces that directly faces the world 510 or the observer's eye 210). In some embodiments, a single light beam (e.g., a collimated beam) may be injected into each waveguide to output an entire field of cloned collimated beams that are directed toward the eye 210 at a particular angle (and amount of divergence) corresponding to the depth plane associated with the particular waveguide. In some embodiments, a single one of the image injection devices 360, 370, 380, 390, 400 may be associated with a plurality (e.g., three) of the waveguides 270, 280, 290, 300, 310 and inject light into the plurality (e.g., three) of the waveguides 270, 280, 290, 300, 310.

[0100] In some embodiments, the image injection devices 360, 370, 380, 390, 400 are discrete displays, each of which generates image information for injection into the corresponding waveguides 270, 280, 290, 300, 310, respectively. In some other embodiments, the image injection devices 360, 370, 380, 390, 400 are output terminals of a single multiplexed display, and the output terminals of the single multiplexed display can convey image information to each of the image injection devices 360, 370, 380, 390, 400 via, for example, one or more optical conduits such as fiber optic cables. It will be appreciated that the image information provided by the image injection devices 360, 370, 380, 390, 400 can include light of different wavelengths or colors (e.g., different component colors as discussed herein).

[0101] In some embodiments, the light injected into the waveguides 270, 280, 290, 300, 310 is provided by a light projector system 520, which includes a light module 530 that can include a light emitter such as a light emitting diode (LED). The light from the light module 530 can be directed to a light modulator 540 (e.g., a spatial light modulator) via a beam splitter 550 and modified by the light modulator 540. The light modulator 540 can be configured to change the perceived intensity of the light injected into the waveguides 270, 280, 290, 300, 310 to encode the light with image information. Examples of spatial light modulators include liquid crystal displays (LCDs), which include liquid crystal on silicon (LCOS) displays. It will be appreciated that the image injection devices 360, 370, 380, 390, 400 are schematically shown, and in some embodiments, these image injection devices can represent different optical paths and positions in a common projection system that is configured to output light into the associated waveguides among the waveguides 270, 280, 290, 300, 310. In some embodiments, the waveguides of the waveguide assembly 260 can act as ideal lenses while relaying the light injected into the waveguides out to the user's eyes. In this concept, the object can be the spatial light modulator 540, and the image can be an image on a depth plane.

[0102] In some embodiments, the display system 250 can be a scanned fiber optic display that includes one or more scanned optical fibers configured to project light into one or more waveguides 270, 280, 290, 300, 310 and ultimately to the viewer's eye 310 in various patterns (e.g., raster scan, helical scan, Lissajous pattern, etc.). In some embodiments, the illustrated image injection devices 360, 370, 380, 390, 400 can schematically represent a single scanned optical fiber or a bundle of scanned optical fibers configured to inject light into one or more waveguides 270, 280, 290, 300, 310. In some other embodiments, the illustrated image injection devices 360, 370, 380, 390, 400 can schematically represent multiple scanned optical fibers or multiple bundles of scanned optical fibers, each of which is configured to inject light into an associated one of the waveguides 270, 280, 290, 300, 310. It will be understood that one or more optical fibers can be configured to transmit light from the optical module 530 to one or more waveguides 270, 280, 290, 300, 310. It will be understood that one or more intermediate optical structures can be provided between the scanned optical fiber or fibers and one or more waveguides 270, 280, 290, 300, 310 to, for example, redirect light exiting the scanned optical fiber to one or more waveguides 270, 280, 290, 300, 310.

[0103] The controller 560 controls the operation of one or more of the stacked waveguide assemblies 260, including the operation of the image injection devices 360, 370, 380, 390, 400, the light source 530, and the light modulator 540. In some embodiments, the controller 560 is part of the local data processing module 140. The controller 560 includes programming (e.g., instructions in a non-transitory medium) for regulating the timing and providing the image information to the waveguides 270, 280, 290, 300, 310 according to any of the various schemes disclosed herein, for example. In some embodiments, the controller can be a single integral device or a distributed system connected by wired or wireless communication channels. In some embodiments, the controller 560 can be part of the processing module 140 or 150 ( Figure 9D ).

[0104] Continuing reference Figure 6, waveguides 270, 280, 290, 300, 310 can be configured to propagate light within each respective waveguide by total internal reflection (TIR). Waveguides 270, 280, 290, 300, 310 can each be planar or have an alternative shape (e.g., curved), having a major top surface and a major bottom surface and an edge extending between those major top and bottom surfaces. In the illustrated configuration, waveguides 270, 280, 290, 300, 310 can each include outcoupling optical elements 570, 580, 590, 600, 610, which are configured to extract light from the waveguide by redirecting the light propagating within each respective waveguide out of the waveguide to output image information to the eye 210. The extracted light can also be referred to as outcoupled light, and the outcoupling optical elements can also be referred to as light extraction optical elements. The extracted light beam can be output by the waveguide at the location where the light propagating in the waveguide impinges on the light extraction optical element. The outcoupling optical elements 570, 580, 590, 600, 610 can be, for example, gratings including diffractive optical features, as further discussed herein. Although illustrated as being disposed at the bottom major surface of waveguides 270, 280, 290, 300, 310 for ease of description and clarity of the drawings, in some embodiments, the outcoupling optical elements 570, 580, 590, 600, 610 can be disposed at the top and / or bottom major surfaces, and / or can be disposed directly within the volume of waveguides 270, 280, 290, 300, 310, as further discussed herein. In some embodiments, the outcoupling optical elements 570, 580, 590, 600, 610 can be formed in a material layer attached to a transparent substrate to form waveguides 270, 280, 290, 300, 310. In some other embodiments, waveguides 270, 280, 290, 300, 310 can be a single-piece material, and the outcoupling optical elements 570, 580, 590, 600, 610 can be formed on and / or within the surface of the piece of material.

[0105] Continue to refer to Figure 6, as discussed herein, each of waveguides 270, 280, 290, 300, 310 is configured to output light to form an image corresponding to a particular depth plane. For example, the waveguide 270 closest to the eye can be configured to deliver collimated light (which is injected into such waveguide 270) to the eye 210. The collimated light can represent an optically infinite focal plane. The next upper waveguide 280 can be configured to send out collimated light that passes through a first lens 350 (e.g., a negative lens) before it can reach the eye 210; such a first lens 350 can be configured to produce a slightly convex wavefront curvature such that the eye / brain interprets the light from this next upper waveguide 280 as coming from a first focal plane that is closer inward from the optically infinite towards the eye 210. Similarly, the third upper waveguide 290 has its output light pass through the first lens 350 and a second lens 340 before reaching the eye 210; the combined optical power of the first lens 350 and the second lens 340 can be configured to produce another increase in the wavefront curvature such that the eye / brain interprets the light from the third waveguide 290 as coming from a second focal plane that is closer inward from the optically infinite towards the person than the light from the next upper waveguide 280.

[0106] The other waveguide layers 300, 310 and lenses 330, 320 are configured similarly, where the highest waveguide 310 in the stack sends its output through all of the lenses between it and the eye, for a total optical power representing the focal plane closest to the person. To compensate for the stack of lenses 320, 330, 340, 350 when viewing / interpreting light from the world 510 on the other side of the stacked waveguide assembly 260, a compensation lens layer 620 can be provided at the top of the stack to compensate for the total optical power of the underlying lens stack 320, 330, 340, 350. Such a configuration provides as many focal planes as there are available waveguide / lens pairings. Both the outcoupling optical elements of the waveguides and the focusing aspects of the lenses can be static (i.e., non-dynamic or electroactive). In some alternative embodiments, one or both can be dynamic using electroactive features.

[0107] In some embodiments, two or more of the waveguides 270, 280, 290, 300, 310 can have the same associated depth plane. For example, multiple waveguides 270, 280, 290, 300, 310 can be configured to output a set of images to the same depth plane, or multiple subsets of the waveguides 270, 280, 290, 300, 310 can be configured to output a set of images to the same multiple depth planes, where there is one set for each depth plane. This can provide the advantage of forming a stitched image to provide an extended field of view at those depth planes.

[0108] Continuing to refer to Figure 6, the output optical elements 570, 580, 590, 600, 610 can be configured to redirect light out of their respective waveguides and output the light with an appropriate amount of divergence or collimation for a particular depth plane associated with the waveguide. Thus, waveguides with different associated depth planes can have different configurations of output optical elements 570, 580, 590, 600, 610, which depend on the associated depth plane to output light with different amounts of divergence. In some embodiments, the light extraction optical elements 570, 580, 590, 600, 610 can be volume or surface features, which can be configured to output light at a specific angle. For example, the light extraction optical elements 570, 580, 590, 600, 610 can be volume holograms, surface holograms, and / or diffraction gratings. In some embodiments, the features 320, 330, 340, 350 can not be lenses; instead, they can simply be spacers (e.g., cladding and / or structures for forming voids).

[0109] In some embodiments, the output optical elements 570, 580, 590, 600, 610 are diffraction features that form a diffraction pattern, or "diffractive optical elements" (also referred to herein as "DOEs"). Preferably, the DOE has a low enough diffraction efficiency such that only a portion of the light beam is deflected away from the eye 210 through each intersection of the DOE, while the remaining portion continues to travel through the waveguide via TIR. The light carrying the image information is thus split into many associated outgoing beams that leave the waveguide at many locations, and the result is a fairly uniform pattern of outgoing emission towards the eye 210 for that particular collimated beam that bounces around within the waveguide.

[0110] In some embodiments, one or more DOEs can be switched between an "on" state in which they actively diffract and an "off" state in which they do not significantly diffract. For example, a switchable DOE can include a polymer dispersed liquid crystal layer, where the microdroplets include a diffraction pattern in a host medium, and the refractive index of the microdroplets can be switched to substantially match the refractive index of the host material (in which case the pattern does not significantly diffract the incident light) or the microdroplets can be switched to a refractive index that does not match the refractive index of the host medium (in which case the pattern actively diffracts the incident light).

[0111] In some embodiments, a camera component 630 (e.g., a digital camera, including visible light and infrared cameras) may be provided to capture images of the eye 210 and / or tissue surrounding the eye 210 to, for example, detect user input and / or monitor the user's physiological state. As used herein, a camera may be any image capture device. In some embodiments, the camera component 630 may include an image capture device and a light source that projects light (e.g., infrared light) toward the eye, which may then be reflected by the eye and detected by the image capture device. In some embodiments, the camera component 630 may be attached to the frame 80( Figure 9D ) and may be in electrical communication with the processing module 140 and / or 150, which may process image information from the camera component 630. In some embodiments, one camera component 630 may be utilized for each eye to separately monitor each eye.

[0112] Now referring to Figure 7 , an example of an output beam exiting a waveguide is shown. One waveguide is illustrated, but it will be understood that in cases where the waveguide assembly 260 includes multiple waveguides, the other waveguides in the waveguide assembly 260( Figure 6 ) may operate similarly. Light 640 is injected into the waveguide 270 at the input surface 460 of the waveguide 270 and propagates within the waveguide 270 by TIR. At the point where the light 640 is incident on the DOE 570, a portion of the light exits the waveguide as an output beam 650. The output beam 650 is illustrated as being substantially parallel, but as discussed herein, it may also be redirected to propagate at an angle toward the eye 210 (e.g., to form a diverging output beam), depending on the depth plane associated with the waveguide 270. It will be understood that a substantially parallel output beam may indicate a waveguide having an outcoupling optical element that outcouples light to form an image that appears to be set on a depth plane at a large distance (e.g., optically infinite) from the eye 210. Other waveguides or other sets of outcoupling optical elements may output a more diverging output beam pattern, which will require the eye 210 to accommodate to a closer distance to focus on the retina and will be interpreted by the brain as light from a distance closer to the eye 210 than optically infinite.

[0113] In some embodiments, a full-color image may be formed at each depth plane by overlapping images of each of the component colors (e.g., three or more component colors). Figure 8Illustrated is an example of a stacked waveguide assembly where each depth plane includes an image formed using multiple different component colors. The illustrated embodiment shows depth planes 240a–240f, although more or fewer depths are also contemplated. Each depth plane may have three or more component color images associated therewith, including: a first image of a first color G; a second image of a second color R; and a third image of a third color B. Different depth planes are indicated in the figures by different numbers for diopters (dpt) following the letters G, R, and B. By way of example only, the numbers following each of these letters indicate the diopter (1 / m), or the inverse distance of the depth plane from the observer, and each box in the figures represents a single component color image. In some embodiments, to account for differences in the eye focusing of light of different wavelengths, the exact positioning of the depth planes for different color components may vary. For example, the different component color images for a given depth plane may be placed on depth planes corresponding to different distances from the user. Such an arrangement may increase visual sensitivity and user comfort and / or may reduce chromatic aberration.

[0114] In some embodiments, light of each component color may be output by a single dedicated waveguide, and thus, each depth plane may have multiple waveguides associated therewith. In such embodiments, each box in the figures including the letters G, R, or B may be understood to represent a separate waveguide, and three waveguides may be provided per depth plane, where three component color images are provided per depth plane. Although the waveguides associated with each depth plane are shown adjacent to each other in this figure, it will be understood that in a physical device, the waveguides may all be arranged in a stack, with one waveguide per layer. In some other embodiments, multiple component colors may be output by the same waveguide, such that, for example, only a single waveguide may be provided per depth plane.

[0115] Continuing to refer Figure 8 , in some embodiments, G is green, R is red, and B is blue. In some other embodiments, other colors associated with other wavelengths of light (including magenta and cyan) may additionally be used or may replace one or more of red, green, or blue.

[0116] It will be understood that references throughout this disclosure to a given light color are to be understood as encompassing light of one or more wavelengths within the range of wavelengths of light that are perceived by an observer as having that given color. For example, red light may include light of one or more wavelengths in the range of approximately 620–780 nm, green light may include light of one or more wavelengths in the range of approximately 492–577 nm, and blue light may include light of one or more wavelengths in the range of approximately 435–493 nm.

[0117] In some embodiments, light source 530 (Figure 6 ) can be configured to emit light at one or more wavelengths outside the visual perception range of an observer, e.g., infrared and / or ultraviolet wavelengths. Additionally, the input, output, and other light redirecting structures of the waveguide of the display 250 can be configured to direct and emit the light towards the user's eye 210 and outside the display, e.g., for imaging and / or user stimulation applications.

[0118] Now referring to Figure 9A , in some embodiments, light incident on the waveguide may need to be redirected to couple the light into the waveguide. Input optics can be used to redirect and couple the light into its corresponding waveguide. Figure 9A FIG. shows an example cross-sectional side view of a plurality of stacked waveguides or a set of stacked waveguides 660 each including input optics. The waveguides can each be configured to output light at one or more different wavelengths or one or more different wavelength ranges. It will be appreciated that the stack 660 can correspond to the stack 260 ( Figure 6 ), and the waveguides of the illustrated stack 660 can correspond to a portion of the plurality of waveguides 270, 280, 290, 300, 310, except that light from one or more of the image injection devices 360, 370, 380, 390, 400 is injected into the waveguide from a location where the desired light redirection for coupling is to occur.

[0119] The illustrated stacked waveguide assembly 660 includes waveguides 670, 680, and 690. Each waveguide includes an associated optical input element (which may also be referred to as an optical input region on the waveguide), where, for example, the optical input element 700 disposed on the main surface (e.g., the upper main surface) of the waveguide 670, the optical input element 710 disposed on the main surface (e.g., the upper main surface) of the waveguide 680, and the optical input element 720 disposed on the main surface (e.g., the upper main surface) of the waveguide 690. In some embodiments, one or more of the optical input elements 700, 710, 720 may be disposed on the bottom main surface of the respective waveguides 670, 680, 690 (particularly, where one or more of the optical input elements are reflective deflecting optical elements). As illustrated, the optical input elements 700, 710, 720 may be disposed on the upper main surface of their respective waveguides 670, 680, 690 (or on top of the next lower waveguide), particularly where those optical input elements are transmissive deflecting optical elements. In some embodiments, the optical input elements 700, 710, 720 may be disposed within the body of the respective waveguides 670, 680, 690. In some embodiments, as discussed herein, the optical input elements 700, 710, 720 are wavelength selective such that they selectively redirect one or more wavelengths of light while transmitting other wavelengths of light. Although illustrated on one side or corner of their respective waveguides 670, 680, 690, it will be understood that in some embodiments, the optical input elements 700, 710, 720 may be disposed in other regions of their respective waveguides 670, 680, 690.

[0120] As illustrated, the optical input elements 700, 710, 720 may be laterally offset from each other. In some embodiments, each optical input element may be offset such that it receives light without the light passing through another optical input element. For example, each of the optical input elements 700, 710, 720 may be configured to receive light from different image injection devices 360, 370, 380, 390, and 400 as shown in Figure 6 and may be separated (e.g., laterally spaced apart) from the other optical input elements 700, 710, 720 such that it substantially does not receive light from the other optical input elements among the optical input elements 700, 710, 720.

[0121] Each waveguide also includes an associated light distribution element, e.g., a light distribution element 730 disposed on the main surface (e.g., the top main surface) of waveguide 670, a light distribution element 740 disposed on the main surface (e.g., the top main surface) of waveguide 680, and a light distribution element 750 disposed on the main surface (e.g., the top main surface) of waveguide 690. In some other embodiments, the light distribution elements 730, 740, 750 may be disposed on the bottom main surfaces of the associated waveguides 670, 680, 690, respectively. In some other embodiments, the light distribution elements 730, 740, 750 may be disposed on the top main surfaces and the bottom main surfaces of the associated waveguides 670, 680, 690, respectively; or the light distribution elements 730, 740, 750 may be disposed on different main surfaces of the top main surfaces and the bottom main surfaces in different associated waveguides 670, 680, 690.

[0122] Waveguides 670, 680, 690 may be separated and isolated by, e.g., a gas, a liquid, and / or a solid material layer. For example, as illustrated, layer 760a may separate waveguides 670 and 680; and layer 760b may separate waveguides 680 and 690. In some embodiments, layers 760a and 760b are formed of a low refractive index material (i.e., a material having a lower refractive index than the material of a directly adjacent one of waveguides 670, 680, 690). Preferably, the refractive index of the material forming layers 760a, 760b is less than the refractive index of the material forming waveguides 670, 680, 690 by 0.05 or more, or 0.10 or less. Advantageously, the lower refractive index layers 760a, 760b may serve as claddings that facilitate total internal reflection (TIR) of light passing through waveguides 670, 680, 690 (e.g., TIR between the top main surface and the bottom main surface of each waveguide). In some embodiments, layers 760a, 760b are formed of air. Although not illustrated, it will be understood that the top and bottom of the illustrated waveguide set 660 may include directly adjacent claddings.

[0123] Preferably, for ease of manufacturing and other considerations, the materials forming waveguides 670, 680, 690 are similar or the same, and the materials forming layers 760a, 760b are similar or the same. In some embodiments, the materials forming waveguides 670, 680, 690 may be different between one or more waveguides, and / or the materials forming layers 760a, 760b may be different, while still maintaining the various refractive index relationships noted above.

[0124] Continuing reference Figure 9A, light rays 770, 780, 790 are incident on waveguide set 660. It will be understood that light rays 770, 780, 790 can be injected into waveguides 670, 680, 690 by one or more image injection devices 360, 370, 380, 390, 400( Figure 6 ).

[0125] In some embodiments, light rays 770, 780, 790 have different properties, e.g., different wavelengths or different wavelength ranges corresponding to different colors. Coupling optical elements 700, 710, 720 each deflect the incident light such that the light propagates through a respective one of waveguides 670, 680, 690 by TIR. In some embodiments, coupling optical elements 700, 710, 720 each selectively deflect one or more specific wavelengths of light while transmitting other wavelengths to the underlying waveguide and associated coupling optical element.

[0126] For example, coupling optical element 700 can be configured to deflect light ray 770 having a first wavelength or wavelength range while transmitting light rays 1242 and 1244 having different second and third wavelengths or wavelength ranges, respectively. The transmitted light ray 780 is incident on coupling optical element 710 and is deflected by coupling optical element 710, which is configured to deflect light of the second wavelength or wavelength range. Light ray 790 is deflected by coupling optical element 720, which is configured to selectively deflect light of the third wavelength or wavelength range.

[0127] Continuing to refer to Figure 9A , the deflected light rays 770, 780, 790 are deflected such that they propagate through corresponding waveguides 670, 680, 690; that is, the coupling optical elements 700, 710, 720 of each waveguide deflect light into that corresponding waveguide 670, 680, 690 to couple the light into that corresponding waveguide. Light rays 770, 780, 790 are deflected at an angle such that the light propagates through the respective waveguides 670, 680, 690 by TIR. Light rays 770, 780, 790 propagate through the respective waveguides 670, 680, 690 by TIR until incident on corresponding light distribution elements 730, 740, 750 of the waveguide.

[0128] Now referring to Figure 9B , there is shown Figure 9APerspective view of an example of multiple stacked waveguides. As described above, the coupled-in light rays 770, 780, 790 are deflected by the coupled-in optical elements 700, 710, 720 respectively, and then propagate through the waveguides 670, 680, 690 by TIR respectively. The light rays 770, 780, 790 then impinge on the light distribution elements 730, 740, 750 respectively. The light distribution elements 730, 740, 750 deflect the light rays 770, 780, 790 such that they propagate towards the coupled-out optical elements 800, 810, 820 respectively.

[0129] In some embodiments, the light distribution elements 730, 740, 750 are orthogonal pupil expanders (OPEs). In some embodiments, the OPE deflects or distributes light to the coupled-out optical elements 800, 810, 820, and in some embodiments the size or spot size of the light beam can also be increased as the light propagates to the coupled-out optical elements. In some embodiments, the light distribution elements 730, 740, 750 can be omitted and the coupled-in optical elements 700, 710, 720 can be configured to deflect light directly to the coupled-out optical elements 800, 810, 820. For example, referring to Figure 9A , the light distribution elements 730, 740, 750 can be replaced by the coupled-out optical elements 800, 810, 820 respectively. In some embodiments, the coupled-out optical elements 800, 810, 820 are exit pupils (EPs) or exit pupil expanders (EPEs) that direct light into the observer's eye 210 ( Figure 7 ). It will be understood that the OPE can be configured to increase the size of the eye box on at least one axis, and the EPE can increase the eye box on an axis that spans (e.g., is orthogonal to) the axis of the OPE. For example, each OPE can be configured to redirect a portion of the light incident on the OPE to the EPE of the same waveguide while allowing the remaining portion of the light to continue propagating down the waveguide. When the remaining light is incident on the OPE again, another portion of the remaining light is redirected to the EPE, and the remaining portion of that portion continues to propagate further down the waveguide, and so on. Similarly, when incident on the EPE, a portion of the incident light is directed out of the waveguide towards the user, and the remaining portion of the light continues to propagate through the waveguide until it is incident on the EP again, at which time another portion of the incident light is directed out of the waveguide, and so on. Thus, a single beam of coupled-in light can be "copied" each time a portion of the light is redirected by the OPE or EPE, forming a field of cloned beams, as shown in Figure 6 . In some embodiments, the OPE and / or EPE can be configured to modify the size of the light beam.

[0130] Thus, referring to Figure 9A and 9B, in some embodiments, the waveguide assembly 660 includes waveguides 670, 680, 690 for each component color; input optical elements 700, 710, 720; light distribution elements (e.g., OPE) 730, 740, 750; and output optical elements (e.g., EPE) 800, 810, 820. The waveguides 670, 680, 690 may be stacked with a gap / cladding between each one. The input optical elements 700, 710, 720 redirect or deflect the incident light (wherein different input optical elements receive light of different wavelengths) into their respective waveguides. The light then propagates at an angle that will result in TIR within the respective waveguides 670, 680, 690. In the illustrated example, the light ray 770 (e.g., blue light) is deflected by the first input optical element 700 in the manner previously described and then continues to bounce downward along the waveguide, interacting with the light distribution element (e.g., OPE) 730 and then the output optical element (e.g., EP) 800. The light rays 780 and 790 (e.g., green light and red light, respectively) will pass through the waveguide 670, wherein the light ray 780 impinges on the input optical element 710 and is deflected by the input optical element 710. The light ray 780 then bounces downward along the waveguide 680 via TIR, continues to its light distribution element (e.g., OPE) 740 and then the output optical element (e.g., EP) 810. Finally, the light ray 790 (e.g., red light) passes through the waveguide 690 to impinge on the light input optical element 720 of the waveguide 690. The light input optical element 720 deflects the light ray 790 such that the light ray propagates to the light distribution element (e.g., OPE) 750 via TIR and then propagates to the output optical element (e.g., EP) 820 via TIR. Then, the output optical element 820 finally couples out the light ray 790 to an observer, who also receives the output light from the other waveguides 670, 680.

[0131] Figure 9C illustrates Figure 9A and Figure 9B a top-down plan view of an example of a plurality of stacked waveguides. As illustrated, the waveguides 670, 680, 690 together with the associated light distribution elements 730, 740, 750 and the associated output optical elements 800, 810, 820 of each waveguide may be vertically aligned. However, as discussed herein, the input optical elements 700, 710, 720 are not vertically aligned; rather, the input optical elements are preferably non-overlapping (e.g., laterally spaced apart as seen in the top-down view). As further discussed herein, this non-overlapping spatial arrangement facilitates injecting light from different sources into different waveguides on a one-to-one basis, thereby allowing a particular light source to be uniquely coupled to a particular waveguide. In some embodiments, an arrangement including non-overlapping spatially separated input optical elements may be referred to as an offset pupil system, and the input optical elements within these arrangements may correspond to sub-pupils.

[0132] Figure 9D illustrates an example of a wearable display system 60 into which various waveguides and related systems disclosed herein can be integrated. In some embodiments, the display system 60 is Figure 6 system 250, where Figure 6 some portions of the system 60 are shown schematically in more detail. For example, Figure 6 the waveguide assembly 260 can be part of the display 70.

[0133] Continuing to refer to Figure 9D , the display system 60 includes a display 70 and various mechanical and electronic modules and systems that support the functions of the display 70. The display 70 can be coupled to a frame 80 that can be worn by a user or observer 90 of the display system and is configured to position the display 70 in front of the eyes of the user 90. In some embodiments, the display 70 can be considered glasses. In some embodiments, a speaker 100 is coupled to the frame 80 and is configured to be located near the ear canal of the user 90 (in some embodiments, another speaker, not shown, can alternatively be located near the other ear canal of the user to provide stereo / plastic sound control). The display system 60 can also include one or more microphones 110 or other devices to detect sound. In some embodiments, the microphone is configured to allow the user to provide input or commands to the system 60 (e.g., selection of voice menu commands, natural language questions, etc.) and / or can allow audio communication with other people (e.g., other users of a similar display system). The microphone can also be configured as a peripheral sensor to collect audio data (e.g., sounds from the user and / or the environment). In some embodiments, the display system 60 can also include one or more outwardly directed environmental sensors 112 that are configured to detect objects, stimuli, people, animals, locations, or other aspects of the world around the user. For example, the environmental sensors 112 can include one or more cameras that can be positioned, for example, facing outward to capture images similar to at least a portion of the normal field of view of the user 90. In some embodiments, the display system can also include a peripheral sensor 120a that can be separated from the frame 80 and attached to the body of the user 90 (e.g., on the head, torso, limb, etc. of the user 90). In some embodiments, the peripheral sensor 120a can be configured to acquire data characterizing the physiological state of the user 90. For example, the sensor 120a can be an electrode.

[0134] Continuing to refer to Figure 9D, the display 70 is operatively coupled to the local data processing module 140 via a communication link 130 (such as via a wired lead or a wireless connection). The local data processing module 140 can be installed in various configurations, such as being fixedly attached to the frame 80, being fixedly attached to a helmet or hat worn by a user, being embedded within a headset, or being detachably attached to the user 90 (e.g., in a backpack configuration, in a belt-coupled configuration). Similarly, the sensor 120a can be operatively coupled to the local processor and data module 140 via a communication link 120b (e.g., a wired lead or a wireless connection). The local processing and data module 140 can include a hardware processor and a digital memory such as a non-volatile memory (e.g., flash memory or a hard disk drive), both of which can be used to assist in processing, caching, and storing data. Alternatively, the local processor and data module 140 can include one or more central processing units (CPUs), graphics processing units (GPUs), dedicated processing hardware, etc. The data can include: a) data captured from sensors (e.g., the sensor can be operatively coupled to the frame 80 or otherwise attached to the user 90), such sensors as image capture devices (such as cameras), microphones, inertial measurement units, accelerometers, compasses, GPS units, radios, gyroscopes, and / or other sensors disclosed herein; and / or b) data obtained and / or processed using the remote processing module 150 and / or the remote data repository 160 (including data related to virtual content), which can be transmitted to the display 70 after such processing or retrieval. The local processing and data module 140 can be operatively coupled to the remote processing module 150 and the remote data repository 160 via communication links 170, 180 (such as via wired or wireless communication links), such that these remote modules 150, 160 are operatively coupled to each other and can be used as resources for the local processing and data module 140. In some embodiments, the local processing and data module 140 can include one or more of an image capture device, a microphone, an inertial measurement unit, an accelerometer, a compass, a GPS unit, a radio, and / or a gyroscope. In some other embodiments, one or more of these sensors can be attached to the frame 80, or can be independent structures that communicate with the local processing and data module 140 via a wired or wireless communication path.

[0135] Continuing to refer to Figure 9D, in some embodiments, the remote processing module 150 may include one or more processors configured to analyze and process data and / or image information, such as one or more central processing units (CPUs), graphics processing units (GPUs), dedicated processing hardware, etc. In some embodiments, the remote data repository 160 may include a digital data storage facility that may be available via the Internet or other network configurations in a "cloud" resource configuration. In some embodiments, the remote data repository 160 may include one or more remote servers that provide information to the local processing and data module 140 and / or the remote processing module 150, such as information for generating augmented reality content. In some embodiments, all data is stored and all computations are performed in the local processing and data module, allowing for fully autonomous use from the remote module. Alternatively, an external system (e.g., a system with one or more processors, one or more computers) including a CPU, GPU, etc. may perform at least a portion of the processing (e.g., generating image information, processing data) and provide information to and receive information from modules 140, 150, 160, e.g., via a wireless or wired connection.

[0136] Adaptive lens assembly

[0137] Referring again to Figure 9A , some display systems include a waveguide assembly 660 configured to form images at multiple virtual depth planes. In the illustrated embodiment, multiple waveguides 670, 680, 690, such as those configured to form an image on one of the different depth planes, may be used to form the image. The waveguide assembly 660 may also include additional waveguides with different optical powers to form images at different virtual depth planes. However, since each of the waveguides 670, 680, 690 increases the overall thickness, weight, and cost of the waveguide assembly 660, it is desirable to use fewer waveguides to form images at multiple virtual depth planes.

[0138] In various embodiments described herein, the display device is configured to form images at different virtual depth planes using a waveguide assembly and one or more adaptive lens assemblies. In some embodiments, the adaptive lens assembly includes liquid crystal, which may form a lens assembly that is lighter and thinner (micrometers) than a conventional lens, and the liquid crystal may advantageously be configured to be switchable (e.g., electrically switchable). Advantageously, such an adaptive lens assembly may reduce the number, thickness, and weight of the waveguide assembly, such as assembly 660.

[0139] As used herein, the optical power (also referred to as refractive power, focusing power, or converging power) is the degree to which a lens, mirror, or other optical system converges or diverges light. It is equal to the reciprocal of the focal length of the device: P = 1 / f. That is, high optical power corresponds to a short focal length. The SI unit of optical power is inverse meter (m -1 -1), which is commonly referred to as diopter. As described herein, a converging lens is described as having positive optical power, while a diverging lens is described as having negative power. Without being bound by theory, when light passes through two or more thin lenses that are relatively close to each other, the optical power of the combined lens can be approximated as the sum of the optical powers of the individual lenses. Thus, when light passes through a first lens having a first optical power P1 and further through a second lens having a second optical power P2, it can be understood that the light is converged or diverged according to the sum of the optical powers P = P1 + P2.

[0140] Figure 10 An example of a display device 1000 is shown, for example, a wearable display device, which includes one or more adaptive lens assemblies, such as a pair of adaptive lens assemblies 1004, 1008 in the optical path 1016, between which a waveguide assembly 1012 is inserted. In some embodiments, the waveguide assembly 1012 may correspond to the waveguide stack 260 or 660. As described herein, the waveguide assembly is configured to propagate light (e.g., visible light) under total internal reflection and couple out light within the optical axis extending from the light output surface of the waveguide (e.g., in a direction perpendicular to the light output surface). Preferably, the light output surface is the main surface of the waveguide (e.g., the main surface of the waveguide can be understood as the wide surface of the waveguide, and the thickness of the waveguide, e.g., the minimum dimension, extends between the wide surfaces). In some embodiments, the light can be coupled out through a diffraction grating. Each of the adaptive lens assemblies 1004, 1008 can be configured to at least partially transmit the coupled-out light passing through it. As shown, each of the adaptive lens assemblies 1004, 1008 can be configured to receive the coupled-out light from the waveguide assembly 1012 and converge or diverge the coupled-out light in the optical axis direction. Each of the adaptive lens assemblies 1004, 1008 can include a waveplate lens and a switchable waveplate assembly, which itself can include a first and a second waveplate lens inserted by the switchable waveplate. Each of the waveplates can be configured to change the polarization state of the coupled-out light passing through the waveplate. The switchable waveplate can be configured to change the polarization state of the coupled-out light passing through the switchable waveplate when activated (e.g., electrically activated).

[0141] As used herein, an adaptive lens assembly refers to a lens assembly having at least one optical property that can be adjusted using an external stimulus, e.g., reversibly activated and deactivated. Among other properties, example optical properties that can be reversibly activated and deactivated include optical power (focal length), phase, polarization, polarization selectivity, transmittance, reflectance, birefringence, and diffraction properties. In various embodiments, the adaptive lens assembly is capable of changing the optical power and polarization state of light passing therethrough by such selective application of an electric field.

[0142] In the illustrated embodiment, each of a pair of adaptive lens assemblies 1004, 1008 is configured to be electrically activated and deactivated, where in the deactivated state, each of the adaptive lens assemblies 1004, 1008 provides a first optical power and when in the activated state, each of the adaptive lens assemblies 1004, 1008 provides a second optical power different from the first optical power. Additionally, in some embodiments, in one state, each of the adaptive lens assemblies 1004, 1008 changes the polarization state of light passing therethrough (e.g., visible light), while in another state, each of the adaptive lens assemblies 1004, 1008 maintains the polarization state of light passing therethrough.

[0143] Still referring to Figure 10 , the display device 1000 further includes a waveguide assembly 1012 inserted between the pair of adaptive lens assemblies 1004, 1008. The waveguide assembly 1012 may be similar to the waveguide assemblies 260 or 660 described above with respect to Figure 6 and 9A -9C, respectively. The waveguide assembly 1012 may include waveguides similar to the waveguides 270, 280, 290, 300, 310 in Figure 6 or the waveguides 670, 680, 690 in Figures 9A - 9C . As described herein, the waveguide may be configured to propagate light in a transverse direction parallel to the main surface of the waveguide under total internal reflection. The waveguide may further be configured to couple out light to output the light to the user's eye 210 through the adaptive lens assembly 1008.

[0144] Still referring to Figure 10, the first adaptive lens assembly 1004 in the pair of adaptive lens assemblies is disposed on a first side of the waveguide assembly 1012, e.g., the side of the world 510 that the user observes, and the second adaptive lens assembly 1008 in the pair of adaptive lens assemblies is disposed on a second side of the waveguide assembly 1012, e.g., the side closest to the user's eye 210. As described below, the pair of configured adaptive lens assemblies provides virtual content from the waveguide assembly 1012 to the user at multiple virtual depth planes, as well as a view of the real world to the user. In some embodiments, there is little or no distortion due to the presence of the adaptive lens assemblies. As described below with respect to Figure 11A and 11B , when the first and second adaptive lens assemblies 1004, 1008 are activated, a virtual content and a view of the real world are provided to the user.

[0145] Figure 11A and 11B illustrate examples of display devices 1100A / 1100B, each display device including an adaptive lens assembly that outputs image information to the user in operation. The display devices 1100A and 1100B in the unpowered state may be structurally identical. The display device 1100A is used herein to illustrate outputting a virtual image to the user, while the display device 1100B is used herein to illustrate sending a real world image to the user through the display device 1100B. The display device 1100A / 1100B includes a pair of adaptive lens assemblies 1004, 1008 that are configured to be electrically activated, e.g., by applying a voltage or current. In some embodiments, in the deactivated state, e.g., when no voltage or current is applied, each of the first switchable lens assembly 1004 and the second switchable lens assembly 1008 has a low optical power, e.g., approximately zero. In some embodiments, in the activated state, e.g., when a voltage or current is applied, the first world-side adaptive lens assembly 1004 on the world side may provide a first net optical power (Pnet1) having a first sign, e.g., a positive optical power. When in the activated state, the second user-side adaptive lens assembly 1008 on the user side may provide a second net optical power (Pnet2) having a second sign, e.g., a negative optical power.

[0146] Figure 11A illustrates according to some embodiments Figure 10An example of a display system that displays virtual content to a user at a virtual depth plane. As described herein, a waveguide assembly 1012 inserted between a pair of adaptive lens assemblies 1004, 1008 includes a waveguide configured to receive light containing virtual image information and propagate the light under total internal reflection. The waveguide assembly 1012 is further configured to couple out the light towards the eye 210, for example, via a diffraction grating. The coupled-out light passes through the second adaptive lens assembly 1008 before entering the eye 210. When activated, the second adaptive lens assembly 1008 has a second net optical power Pnet2, which may have a negative value such that the user sees a virtual image located at the virtual depth plane 1104.

[0147] In some embodiments, the second net optical power Pnet2 can be electrically adjusted to adjust the second net optical power (Pnet2) of the second adaptive lens assembly 1008, thereby adjusting the distance to the virtual depth plane 1104. For example, as a virtual object "moves" closer or farther relative to the eye 210 within the virtual three-dimensional space, the second net optical power Pnet2 of the second adaptive lens assembly 1008 can be adjusted accordingly such that the virtual depth plane 1104 is adjusted to track the virtual object. Thus, the user may experience relatively few or no accommodation / convergence mismatches that exceed an acceptable threshold. In some embodiments, the magnitude of the distance to the virtual depth plane 1104 can be adjusted in discontinuous steps, while in some other embodiments, the magnitude of the distance to the virtual depth plane 1104 can be adjusted continuously.

[0148] Figure 11B Shows according to some embodiments Figure 10Example of a display system that provides a view of real-world content to a user. When the second adaptive lens assembly 1008 is activated to have a second net optical power (Pnet2) to display virtual content at the virtual depth plane 1104, the light from the real world passing through the second adaptive lens assembly 1008 can also be converged or diverged according to the Pnet2 of the activated second adaptive lens assembly 1008. Thus, objects in the real world may appear out of focus. To mitigate this distortion, according to some embodiments, when activated, the first and second adaptive lens assemblies 1004, 1008 can be configured to have optical powers with opposite signs. In some embodiments, the light passing through the first and second adaptive lens assemblies 1004, 1008 converges or diverges according to the combined optical power, the magnitude of which is approximately the difference between the magnitudes of the first and second net optical powers Pnet1, Pnet2 of the first and second adaptive lens assemblies 1004, 1008, respectively. In some embodiments, the waveguide assembly 1012 may also have an optical power, and the adaptive lens assembly 1008 can be configured to address the distortion caused by both the lens assembly 1004 and the waveguide assembly 1012. For example, the sign of the optical power of the adaptive lens assembly 1008 can be opposite to the sum of the optical powers of the lens assembly 1004 and the waveguide assembly 1012.

[0149] In some embodiments, the first adaptive lens assembly 1004 is configured to have a first net optical power Pnet1, the magnitude of which is close to or equal to the magnitude of the second net optical power Pnet2 of the second adaptive lens assembly 1008. As a result, when the first adaptive lens assembly 1004 and the second adaptive lens assembly 1008 are activated simultaneously, objects in the real world appear relatively unaffected by the optical power of the second adaptive lens assembly 1008 provided for displaying virtual content.

[0150] In some embodiments, the first adaptive lens assembly 1004 can be configured such that when activated, the first net optical power Pnet1 dynamically matches the second net optical power Pnet2 of the second adaptive lens assembly 1008. For example, when the second net optical power Pnet1 of the second switchable assembly 1008 is adjusted to track a moving virtual object within the virtual three-dimensional space, the first net optical power Pnet1 of the first adaptive lens assembly 1004 can be dynamically adjusted such that the magnitude of the combined optical power P = Pnet1 + Pnet2 is maintained less than a predetermined value. Thus, according to an embodiment, unacceptable defocusing of objects in the real world can be prevented by compensating the second net optical power (Pnet2) (which can be negative) of the second adaptive lens assembly 1008 with the first net optical power (Pnet1) of the first adaptive lens assembly 1004, such that the combined optical power P = Pnet1 + Pnet2 remains small, e.g., approximately 0 m.-1 .

[0151] Figure 12 An example of a display device 1500 is shown. The display device 1500 includes a pair of adaptive lens assemblies, each of which includes an adaptive lens sub-assembly including a waveplate lens and a switchable waveplate. Each of the first and second adaptive lens assemblies 1504, 1508 includes a plurality of waveplate lenses stacked alternately with a plurality of switchable waveplate assemblies. The plurality of waveplate lenses are, for example, the first to third waveplate lenses 1308-1, 1308-2, 1308-3, and the plurality of switchable waveplate assemblies are, for example, the first to third switchable waveplate assemblies 1312-1, 1312-2, 1312-3. The waveplate lenses 1308-1, 1308-2, 1308-3 and the adjacent switchable waveplate assemblies 1312-1, 1312-2, 1312-3 form sub-assemblies 1504-1, 1504-2, 1504-3 respectively. Each of the plurality of switchable waveplate assemblies 1312 can be independently activated using a switching circuit. In some embodiments, depending on different net optical powers, electrically activating different switchable waveplates in the switchable waveplates causes light passing through the adaptive lens assembly to diverge or converge. The magnitude of the different net optical powers is approximately the sum of the optical powers of the immediately adjacent waveplate lenses inserted by different switchable waveplate assemblies in the switchable waveplate assembly.

[0152] Advantageously, by selecting one or more different sub-assemblies among the sub-assemblies 1508-1, 1508-2, 1508-3 in the second adaptive lens assembly 1508, virtual images at different depth planes can be displayed to the user, and by additionally selecting different corresponding sub-assemblies among the sub-assemblies 1504-1, 1504-2, 1504-3 in the first adaptive lens assembly 1504, defocusing or distortion of the real-world image that may be caused by the optical powers of the sub-assemblies 1508-1, 1508-2, 1508-3 can be compensated for or reduced.

[0153] Adaptive lens assembly with a fixed lens

[0154] In the above example display device including an adaptive lens assembly, the adaptive lens assembly including a waveplate lens and a switchable waveplate has a reduced number of waveguides among other advantages, thereby reducing the weight and thickness of the entire device. In some embodiments, additional fixed lenses can be stacked on one or more adaptive lens assemblies. Advantageously, the additional lenses provide various possible benefits. For example, in some cases, such lenses can be provided to increase additional optical power. Additionally, some wearable display devices using some embodiments (such as regarding Figure 10The user of the wearable device 1000 described has eyes with refractive errors that prevent light from focusing correctly on the retina of their eyes. In some embodiments, an additional lens element may be configured to provide a specific prescription optical power to allow the user to clearly view image information projected by the display and / or image information transmitted from the real world through the display. Additionally, the additional lens may be provided with surfaces having curvature to better conform the device to the user's facial profile, better integrate with a normal eyeglass frame, and / or provide a more aesthetically pleasing appearance for the display device.

[0155] Figure 13A and Figure 13B FIG. shows a display device including a pair of adaptive lens assemblies and a pair of fixed lenses according to some embodiments. As described above, the display device 1800A / 1800B includes a pair of adaptive lens assemblies (e.g., Figure 12 1504, 1508 in ) and a waveguide assembly 1012 inserted between the pair of adaptive lens assemblies, where the waveguide assembly includes a waveguide configured to propagate light under total internal reflection and couple the light out to one of the pair of adaptive lens assemblies (including 1005, 1504 on one side and 1508, 1008 on the other side) to display virtual content on a plurality of virtual depth planes.

[0156] As described above, in some cases, it may be desirable to add additional fixed lenses, such as corrective lenses, to allow the user to view more clearly. In some embodiments, a first fixed focusing lens element 1808 may be provided between the waveguide assembly 1012 and the observer's eye 210. The addition of the first fixed focusing lens element may provide an appropriate adjustment to adjust the light (which may include virtual content) coupled out from the waveguide assembly 1012 to be correctly focused on the observer's eye 210. However, the first fixed lens element 1808 is also in the path of light propagating from the world 510 to the observer's eye 210. As a result, the first lens element may modify the light from the surrounding environment, thereby causing aberrations in the observer's world view. To correct such aberrations, a second fixed focusing lens element 1804 may be provided on the side of the waveguide assembly 1012 opposite the first variable focusing lens element 1808. The second fixed focusing lens element 1804 may be configured to compensate for the aberrations caused by the first variable focusing lens element 1808.

[0157] In some embodiments, the focusing of the second fixed focusing lens element 1804 may be inverse or opposite to the focusing of the first fixed focusing lens element 1808. For example, if the first fixed focusing lens element 1808 has a positive optical power, the second fixed focusing lens element 1804 may have a negative optical power, and vice versa. In some embodiments, they may have similar magnitudes.

[0158] In some embodiments, a display device 1800A / 1800B without fixed focusing lens elements 1804, 1808 may not have sufficient optical power, and the first variable focusing lens element may be configured to provide an appropriate amount of additional divergence to the light for image information so that the image information is interpreted by an observer as being located on a specific depth plane.

[0159] It will be understood that the first and second fixed focusing lens elements 1804, 1808 may be provided for one eye of the observer, and third and fourth fixed focusing lens elements (not shown), which may be similar to the first and second fixed focusing lens elements respectively (but may have different optical powers), may be provided for the other eye of the observer.

[0160] In various embodiments, each of the first and second fixed focusing lens elements may provide a net optical power (positive or negative) in the range between about ±5.0 diopters and 0 diopters, ±4.0 diopters and 0 diopters, ±3.0 diopters and 0 diopters, ±2.0 diopters and 0 diopters, ±1.0 diopters and 0 diopters, including any range defined by these values, such as ±1.5 diopters.

[0161] In some embodiments, such as Figure 13A and 13B shown in, for example, the first fixed focusing lens element 1804, which may be a concave lens or a plano-concave lens, has a positive optical power, and the second fixed focusing lens element 1808, which may be a convex lens or a plano-convex lens, has a negative optical power, such that the optical powers of the first and second focusing lens elements 1804, 1808 compensate each other. However, in some other embodiments, the second fixed focusing lens element 1808 may have a positive optical power, and the first fixed focusing lens element 1804 may have a negative optical power, such that the optical powers of the first and second fixed focusing lens elements 1804, 1808 may compensate each other.

[0162] Figure 14 A display device 1900 is shown in accordance with some other embodiments. Similar to the display devices 1800A / 1800B described above with respect to Figure 13A , 13B the display device 1900 includes a pair of adaptive lens assemblies (e.g., Figure 12 1504, 1508 in Figure 13A and 13BUnlike the display devices 1800A / 1800B, in order to adjust the light including virtual content coupled out from the waveguide assembly 1012 to be correctly focused on the observer's eye 210, the waveguide assembly 1012 can be configured to have a built-in optical power instead of having a first fixed focusing lens element 1808 between the waveguide assembly 1012 and the observer's eye 210. Similar to the above-described display devices 1800A / 1800B, the built-in optical power in the waveguide assembly 1012 can modify the wavefront of the light from the surrounding environment, thereby causing aberration in the observer's world view. To correct this aberration, a fixed focusing lens element 1804 similar to the second fixed focusing lens element 1804 described above with respect to Figure 13A and 13B can be provided between the world and the waveguide assembly 1012. Similar to the compensation mechanism described above with respect to Figure 13A and 13B , the fixed focusing lens element 1804 can be configured to compensate for the aberration caused by the built-in optical power in the waveguide assembly 1012. In some embodiments, the built-in optical power in the waveguide assembly 1012 can have a negative value, and the optical power of the fixed focusing lens element 1804 can have a positive value, such that the optical powers of the waveguide assembly and the fixed focusing lens element compensate each other. Various characteristics of the fixed focusing lens element 1804 are similar to those described above with respect to Figure 13A and 13B .

[0163] It will be understood that in the Figure 14 illustrated embodiment, although the fixed focusing lens element 1804 is provided between the world 510 and the waveguide assembly 1012, other embodiments are possible. For example, similar to the first fixed focusing lens element 1808 described above with respect to Figure 13A and 13B , a fixed focusing lens element 1808 can be provided between the eye 210 and the waveguide assembly 1012. In these embodiments, the built-in optical power in the waveguide assembly 1012 can have a positive value, and the optical power of the fixed focusing lens element 1808 can have a negative value, such that the optical powers of the waveguide assembly and the fixed focusing lens element compensate each other (e.g., sum to substantially 0).

[0164] Switchable variable focusing element component

[0165] Figure 15 Shows an example adaptive lens assembly 1200 including three adaptive lens sub-assemblies 1210. The adaptive lens assembly 1200 can be, for example, the front lens assembly 1004, 1504 or the rear lens assembly 1008, 1508, as Figures 10 - 12As shown. Each layer 1210 includes a waveplate lens 1212 and a switchable liquid crystal layer 1214. A conductive layer 1216, such as one or more wiring or screen layers, is included within each of some of the components 1210 for selectively switching the switchable liquid crystal layer 1214. In some proposed configurations, the sub-component 1210 may require an additional support substrate 1218 and an alignment layer 1222. An adhesive 1220 and additional coatings 1224 (e.g., anti-reflection layers) are provided between the respective layers and between the lens layers 1210. It will be appreciated that the presence of multiple support substrates 1218 and alignment layers 1222 can significantly increase the weight and thickness of the adaptive lens assembly 1200. Thus, a thinner and lighter adaptive lens assembly structure may be desired.

[0166] Figure 16A and 16B FIG. shows an exemplary adaptive lens assembly 1400 according to various embodiments, each adaptive lens assembly 1400 including three adaptive lens sub-components. Advantageously, the adaptive lens assembly 1400 has a simplified structure relative to Figure 15 the adaptive lens assembly 1200. In some embodiments, Figure 16A and 16B the structure shown can advantageously provide an adaptive lens assembly that is thinner and lighter than existing adaptive lens assemblies and can be manufactured more efficiently. Figure 16A and 16B Each of the illustrated adaptive lens assemblies 1400 depicted in FIGS. and includes three adaptive lens sub-components 1410. However, it will be appreciated that the adaptive lens assembly 1400 can be implemented with fewer than three adaptive lens sub-components (e.g., one or two sub-components) or more than three adaptive lens sub-components (e.g., four, five, six, or more sub-components). It will be appreciated that the adaptive lens assembly 1400 can correspond to Figures 10 - 14 the lens assemblies 1004, 1504, 1008, 1508 in FIGS., such that the adaptive lens assembly 1400 can be used in place of the lens assemblies 1004, 1504, 1008, 1508.

[0167] Continuing to refer to Figure 16A and 16B , the adaptive lens assembly 1400 includes three adaptive lens sub-components 1410 coupled by an adhesive layer 1424 (e.g., including an index-matching adhesive). Each adaptive lens sub-component 1410 includes at least one waveplate lens 1412, 1412a, 1412b. For example, Figure 16A FIG. depicts an adaptive lens sub-component 1410 including a single waveplate lens 1412, while Figure 16BAn adaptive lens subassembly 1410 is shown that includes a first waveplate lens 1412a and a second waveplate lens 1412b. In the case where the lenses 1412a, 1412b are of a type that affects only a subset of wavelengths, Figure 16B the multi-lens configuration shown may be desirable. Thus, multiple adjacent lenses 1412a, 1412b can be combined to form a system that will provide a desired optical power over a larger wavelength range.

[0168] Each adaptive lens subassembly 1410 further includes a switchable waveplate assembly that includes two quarter-waveplates 1416 and a switching unit wall 1418 that defines an enclosed volume between the quarter-waveplates 1416. Preferably, the quarter-waveplates 1416 are formed of a light-transmissive material that is bendable (allowing the quarter-waveplates 1416 to be rolled up and unrolled), mechanically stable, and sufficiently inelastic for roll-to-roll processing as disclosed herein. Preferably, the material does not include liquid crystal. Examples of suitable materials for the quarter-waveplates 1416 include plastic (polymer) sheets such as polycarbonate and the like.

[0169] The quarter-waveplates 1416 and the switching unit wall 1418 encapsulate a switching medium 1414 (e.g., a liquid crystal material) and a conductive material 1420 (e.g., wiring, conductive mesh, etc.). In some embodiments, the conductive material 1420 is an indium tin oxide (ITO) layer that can be patterned into a pattern of electrodes. An alignment layer may be provided between the switchable waveplate assembly and the waveplate lenses 1412, 1412a, 1412b. The alignment layer may include one or more alignment structures for proper vertical, horizontal, and / or rotational alignment of the adaptive lens subassembly 1410. Alternatively, in some embodiments, the alignment layer 1422 may be omitted and one or more alignment structures may be added to and / or imprinted on the surfaces of adjacent quarter-waveplates 1416 and / or lenses 1412, 1412a.

[0170] Relative to Figure 15 the adaptive lens subassembly 1210 shown, Figure 16A and 16B the adaptive lens subassembly 1410 shown may advantageously have fewer component layers. The quarter-waveplates 1416 can provide sufficient structural support for each lens subassembly 1410 such that no additional support substrate 1218 ( Figure 15 ) is required. Additionally, the switchable waveplate of the adaptive lens subassembly 1410 can include a conductive material 1420 in the form of a wire mesh or wiring integral with the quarter-waveplates 1416 and located within the space occupied by the switchable waveplate layer 1414 (e.g., a liquid crystal layer) such that no additional conductive layer 1216 ( Figure 15)。As a non - limiting example of the advantageous thin adaptive lens assembly described herein, Figure 16B the adaptive lens assembly 1400 depicted in Figure 16B can have an overall thickness between 1 mm and 3 mm, for example, approximately 1.3 mm. For example, each quarter - wave plate can have a thickness between 100 microns and 300 microns (e.g., 200 microns), each switching cell wall 1418 can have a thickness between 5 and 20 microns (e.g., 10 microns), each wave - plate lens 1412a, 1412b can have a thickness between 1 and 5 microns (e.g., 2 microns), and each alignment layer (if present) can have a thickness less than 100 nm (e.g., between 20 nm and 30 nm). Thus, each adaptive lens sub - assembly 1410 can have a thickness of approximately 414 microns. The adhesive layers 1424 can each have a thickness between 10 and 50 microns (e.g., 20 microns), such that the adaptive lens assembly 1400 has a total thickness of approximately 1.3 mm.

[0171] Method and apparatus for manufacturing a variable focusing element

[0172] Figures 17A - 17E An example process for manufacturing an adaptive lens assembly, such as the adaptive lens assembly 1400 described with reference to Figure 16A and 16B is shown. It will be understood that various parts of the process can be added or omitted without departing from the scope of the present disclosure. As will be described in more detail, the process generally can include forming a quarter - wave plate substrate 1430 and a lens substrate 1440 (which can be formed by adding a lens layer to an existing quarter - wave plate substrate 1430), and combining the quarter - wave plate substrate 1430 with the lens substrate 1440 to form an adaptive lens sub - assembly 1410 having a gap or volume that encapsulates Figure 16A and 16B the switchable liquid - crystal layer 1414. Then, multiple adaptive lens sub - assemblies 1410 can be combined in a stack (e.g., bonded together by a refractive - index - matching adhesive layer) to form the adaptive lens assembly 1400.

[0173] As Figure 17A shown, the conductive material 1420 can be formed on each quarter - wave plate 1416 as a screen and / or wiring array (e.g., parallel wiring) to form the quarter - wave plate substrate 1430. For example, the conductive material 1420 can be directly formed on each quarter - wave plate 1416 by a process including one or more of imprinting, deposition, etching, sputtering, and / or cleaning. In this context, for example, with respect to Figures 21A - 27DVarious methods for forming the pattern of the conductive material 1420 are further discussed. Additionally, methods for forming the pattern of the conductive material 1420 are also disclosed in U.S. Patent Application No. 15 / 683,706, filed on August 22, 2017, the entire disclosure of which is incorporated herein by reference. In some embodiments, a metal layer may be deposited on the quarter-wave plate substrate 1430 and then patterned to define electrodes that form an electrode pattern on the surface of the substrate 1430. In various embodiments, the conductive material 1420 may be formed on a sheet of the quarter-wave plate substrate, on an individual quarter-wave plate layer, and / or on a larger roll of the quarter-wave plate substrate (e.g., in a roll-to-roll manufacturing process). In some embodiments, the orientation, size, spacing, or other aspects of the conductive layer may be selected such that the wiring forms an alignment guide for the liquid crystal layer 1414 ( Figure 16A , 16B ). In some embodiments, additional surface features may be further imprinted into the quarter-wave plate substrate to further guide the alignment of the liquid crystal molecules in the liquid crystal layer 1414. In some embodiments, the substrate supplied on the first roll may include a pattern of previously formed electrodes on the back side of the substrate. Other methods of forming features on the substrate are also disclosed in U.S. Patent Application No. 15 / 990,155, filed on May 25, 2018, the entire disclosure of which is incorporated herein by reference.

[0174] Figure 17B Depicts another step in an exemplary manufacturing process. As Figure 17B shown, the quarter-wave plate 1416 has been provided with an alignment layer 1422, a first wave plate lens 1412a, and a second wave plate lens 1412b to form a lens substrate 1440. In some embodiments, the alignment layer 1422 may include one or more alignment features printed on the side of the quarter-wave plate 1416 opposite to the electrodes or the conductive material 1420. After creating the alignment layer 1422 and / or other alignment structures on the surface of the quarter-wave plate 1416, the first wave plate lens 1412a and the second wave plate lens 1412b are formed. For example, each lens 1412a, 1412b may be formed by depositing a liquid crystal layer (e.g., by a slot die or other deposition device) and curing each layer to polymerize the liquid crystal and form the wave plate lenses 1412a, 1412b. It will be understood that the alignment structures of the alignment layer 1422 and / or the alignment structures on the surface of the quarter-wave plate 1416 assist in the alignment of the liquid crystal molecules in the first wave plate lens 1412a. Then, when the first lens 1412a is cured, for example, by ultraviolet (UV) radiation and / or heating, the alignment of the crystals (e.g., by the polymerization of the liquid crystal molecules) may be maintained. The second lens 1412b may be similarly applied in a flowable form and cured using UV radiation and / or heating.

[0175] AsFigure 17C As shown, a switching cell wall 1418 can be further added to the side of the lens substrate 1440 that includes the conductive material 1420. For example, the cell wall 1418 can include an inkjet-printable material such that the cell wall 1418 can be printed onto the quarter-wave plate 1416 by inkjet printing. In some embodiments, additional spacer structures can be added at positions between the cell walls 1418 to maintain the substrate spacing along all positions between the cell walls 1418. For example, the spacer structures can be inkjet printed with the same or a different material as that used to print the cell walls 1418. Additionally, during the inkjet printing stage, the conductive material can be printed to interconnect the conductive material 1420. For example, if the conductive material 1420 includes an array of parallel wiring, one or more lines of conductive inkjet-printable material can be printed perpendicular to or at an angle to the parallel wiring such that the conductive material 1420 is interconnected and a voltage difference can be effectively applied across Figure 16A and 16B the liquid crystal layer 1414 as shown. In an exemplary manufacturing process, Figure 17B the components shown in Figure 17C can be formed in a roll-to-roll process and cut into sheets before printing the cell walls 1418 as shown in

[0176] As Figure 17DAs shown, a quarter-wave plate substrate 1430 is coupled to a lens substrate 1440 to complete the adaptive lens subassembly 1410. A gap created between the quarter-wave plate substrate 1430 and the lens substrate 1440 is filled with a liquid crystal material. For example, the lens substrate 1440 can be placed in a horizontal orientation. The liquid crystal material can be dispersed onto the lens substrate 1440 such that the space between the cell walls 1418 is filled with the liquid crystal material. The quarter-wave plate substrate 1430 can then be glued or otherwise secured in place against the lens substrate 1440 to hold the liquid crystal material. Preferably, the adaptive lens subassembly 1410 is formed such that no air is trapped by the liquid crystal material. For example, the filling and assembly can be performed in a vacuum and / or the space for the liquid crystal can be overfilled and vent holes provided in at least one of the cell walls 1418 such that the space between the quarter-wave plates 1416 is substantially filled with the switching medium and substantially free of air. In some other embodiments, the lens substrate 1440 and the quarter-wave plate substrate 1430 can be adhered together to form an open volume, after which the liquid crystal is introduced to fill the volume. Although the cell walls 1418 are shown as being printed on the lens substrate 1440, in some embodiments, the cell walls 1418 can be printed on the quarter-wave plate substrate 1430 instead of on the lens substrate 1440, and the filling and assembly steps can be performed by placing the lens substrate 1440 on top of the quarter-wave plate substrate. In some embodiments, portions of the cell walls 1418 can be printed on both the quarter-wave plate substrate 1430 and the lens substrate 1440.

[0177] After the adaptive lens subassembly 1410 is formed, it can be stacked with one or more additional adaptive lens subassemblies 1410 to form an adaptive lens assembly 1400 including a stack of adaptive lens subassemblies 1410 as Figure 17E shown. Each pair of adaptive lens subassemblies 1410 can be coupled together by an adhesive layer 1424. It will be appreciated that the relative orientation of the wave plates with respect to each other affects the optical characteristics of the subassembly 1410 and the larger adaptive lens assembly 1400. Preferably, when the adaptive lens subassemblies 1410 are coupled together, it may be desirable to align each lens subassembly 1410 with an adjacent lens subassembly 1410 with a precision of, for example, within approximately 100 microns laterally in the x and y dimensions and a rotation of approximately 0.1 mrad.

[0178] Figure 18A An example apparatus for roll-to-roll manufacturing of a lens substrate using an optical alignment process for an adaptive lens assembly is shown. The lens substrate 1650 formed by the apparatus 1600A can be, for example Figure 17BThe lens substrate 1440 depicted. Device 1400A is configured to receive a supply substrate 1605 in the form of a supply substrate roll, which can be disposed around a roller 1602 and produce a lens substrate 1650, which can similarly be in the form of a lens substrate roll 1655 for further processing. In some embodiments, the supply substrate can have a composition and / or cross-sectional profile consistent with Figure 17A the quarter-wave plate substrate 1430 depicted therein.

[0179] The supply substrate roll 1602 can include a supply substrate 1605 having a protective film 1610. The protective film 1610 can be removed before applying additional layers. An alignment slit die 1615 applies an alignment layer 1617, which can include a photosensitive material such as a resist material (e.g., a photoresist, such as a positive photoresist or a negative photoresist) or a holographic medium on which holographic recording can be performed. The supply substrate 1605 can travel on an alignment application roller 1619 near the alignment slit die 1615 (e.g., the alignment application roller 1619 can be located directly below or near the alignment slit die 1615). The alignment application roller 1619 can stabilize the supply substrate 1605 as it travels below the alignment slit die 1615 to ensure that the alignment layer 1617 is uniformly coated on the supply substrate 1605. The alignment layer 1617 on the supply substrate 1605 can include a solvent, which can be at least partially removed by, for example, heating in an oven 1620, irradiation, or other solvent removal methods to prepare the alignment layer 1617 for subsequent processing. As used herein, it will be understood that an oven is a device that provides thermal energy to heat an object. After removing the solvent from the alignment layer 1617, an optical aligner 1625 creates an alignment pattern in the alignment layer 1617. For example, the optical aligner 1625 can create the pattern using various lithography techniques, such as direct write (maskless) lithography, lithography using an optical mask and / or a large exposure lens, an optical master lens, etc. In some embodiments, the alignment layer 1617 can be a holographic medium, and the optical aligner 1625 can direct light onto the medium for direct holographic recording. In some embodiments, the substrate 1605 and the alignment layer 1617 can be fixed when the optical aligner 1625 produces an alignment pattern in the alignment layer 1617.

[0180] After imprinting and curing the alignment layer, the first lens slit die 1630 applies a first waveplate lens layer 1632 onto the alignment layer 1617. A first waveplate lens application roller 1634 can be provided to stabilize the supply substrate 1605 and the alignment layer 1617 as the supply substrate 1605 and the alignment layer 1617 travel under the first lens slit die 1615, to ensure that the first waveplate lens layer 1632 is uniformly coated on the alignment layer 1617. In some embodiments, the first waveplate lens layer 1632 includes liquid crystal. The liquid crystal molecules of the liquid crystal layer can adopt an alignment that is at least partially determined by the pattern and / or structure in the alignment layer 1617 adjacent to the first waveplate lens layer 1632. The solvent present in the first waveplate lens layer can be removed by drying and / or passing the substrate through an oven 1637 or other heat source. An ultraviolet (UV) light source then irradiates the first waveplate lens layer 1632 with UV light to cure the first waveplate lens layer 1632, which can polymerize the liquid crystal molecules to lock the orientation of these molecules.

[0181] After depositing and curing the first waveplate lens layer 1632, an optional second waveplate lens layer 1642 can be added. The second lens slit die 1640 deposits the second waveplate lens layer 1642 as a liquid crystal polymer. A second lens application roller 1644 can be provided to stabilize the supply substrate 1605, the alignment layer 1617, and the first waveplate lens layer 1632 as they travel under the second lens slit die 1640, to ensure that the second waveplate lens layer 1642 is uniformly coated on the first waveplate lens layer 1632. The second waveplate lens layer 1642 can be similarly cured by radiation from a UV light source 1645, and the solvent can be removed by applying heat in an oven 1647. It will be understood that a single waveplate lens layer 1632 or more than two waveplate lens layers can be added by a device similar to Figure 18A the device 1600A. For example, if three waveplate lens layers are required, the device 1600A can have more lens slit dies (e.g., three lens slit dies) to apply additional waveplate lens layers.

[0182] When all the waveplate lens layers 1632, 1642 are applied and cured, the resulting lens substrate 1650 can be wound onto a lens substrate roller 1655. In some embodiments, an additional protective film 1652 can be applied to one or both sides of the lens substrate 1650 to protect the surface and structure of the lens substrate 1650 during handling of the lens substrate roll 1655.

[0183] Figures 18B - 18C Other examples of devices for roll-to-roll manufacturing of lens substrates are shown. Similar to Figure 18ADevices 1600A, 1600B, and 1600C are configured to receive a supply substrate 1605 in the form of a supply substrate roll disposed around a roller 1602 and produce a lens substrate 1650, which can similarly be in the form of a lens substrate roll 1655 for further processing. Device 1600B also includes lens slit dies 1630, 1640 to apply liquid crystal polymer waveplate lens layers 1632, 1642, which can be cured by UV light sources 1635, 1645 and / or heat sources 1637, 1647.

[0184] Devices 1600B and 1600C are configured to perform an imprint alignment process, in which alignment features 1662 are added to the surface of the supply substrate 1605 by imprinting. Deposition devices 1660, such as an inkjet printer or a slit die, a conformal roll template (CRT) reel 1665, and a curing device 6070, such as a UV light source, can be used to form the imprint alignment. The deposition device 1660 can be located at various positions within devices 1600B, 1600C. In Figure 18B the example configuration of device 1600B shown, the deposition device 1660 is located upstream of the CRT reel 1665 to directly apply an imprintable material onto the supply substrate 1605. It will be understood that the device is configured to move the substrate in a particular direction (e.g., from roller 1602 to substrate roll 1655), and thus, the terms "upstream" and "downstream" refer to points in the substrate path. "Upstream" refers to a position opposite to the direction in which the device is configured to move the substrate, while "downstream" refers to a position in the direction in which the device is configured to move the substrate.

[0185] In Figure 18B the configuration shown, when the supply substrate 1605 passes through the deposition device 1660, the deposition device 1660 deposits a layer or pattern of droplets onto the supply substrate 1605. In some embodiments, the pattern of droplets can form a continuous layer of the material to be imprinted, e.g., a resist material. An alignment printing roll 1664 can be provided to stabilize the supply substrate 1605 as it travels past the deposition device 1660 to provide a stable surface and enable the deposition device 1660 to deposit the material onto the supply substrate 1605. One side of the supply substrate 1605 bears the deposited material and then contacts the CRT reel 1665. The surface of the CRT reel 1665 includes a pattern of physical features that imprint a pattern in the deposited imprintable material on the surface of the supply substrate 1605. Alternatively, as Figure 18CAs shown in the configuration of the device 1600C, the deposition device 1660 can be placed to directly deposit the imprintable material onto the CRT reel 1665. In this case, the imprintable material on the surface of the CRT reel 1665 can be applied to the surface of the supply substrate 1605, and when the CRT reel 1665 contacts the supply substrate 1605, the material is imprinted and adhered to the supply substrate 1605.

[0186] The UV light source 1670 cures the imprinted material so that the negative tone of the features on the surface of the CRT reel 1665 remains on the supply substrate 1605 as the alignment feature 1662. When the liquid crystal polymer for the first waveplate lens layer 1632 is applied to the supply substrate 1605 above the alignment feature 1662 at the first lens slit mold 1630, the alignment feature 1662 can guide the alignment of the crystals of the liquid crystal polymer before curing caused by an energy source 1635 such as a UV light source. In some embodiments, the imprinted layer applied by the device 1600B forms an imprinting alignment process that allows for continuous operation of the device 1600B (e.g., continuous processing of the entire roll of the supply substrate 1605 to the lens substrate 1650), because the imprinting alignment process can be continuously operated without pausing parts of the supply substrate 1605 for, e.g., fixed optical alignment.

[0187] In some embodiments, the Figures 18A - 18C roll-to-roll manufacturing process described and depicted can be performed, for example, using different manufacturing devices in two or more sub-processes. Referring to Figure 18D , the device 1600D can implement a first roll-to-roll manufacturing process to produce an intermediate substrate 1607 with alignment features from the supply substrate 1605. Referring to Figure 18E , the device 1600E can then implement a second roll-to-roll manufacturing process to use the intermediate substrate 1607 to produce a lens substrate 1655 with a deposited liquid crystal layer.

[0188] Referring to Figure 18D , the device 1600D is configured to perform the same as Figure 18B and 18CA stamping alignment process that is partially similar to the stamping alignment process. Device 1600D is configured to receive a supply substrate 1605 in the form of a supply substrate roll disposed around a supply substrate roll 1602. In some embodiments, the supply substrate roll includes a protective film 1610 that can be removed before alignment features are formed on the supply substrate 1605. The supply substrate 1605 travels through device 1600D supported by a plurality of supply substrate rollers 1676, which can be located, for example, at a point where the path of the supply substrate 1605 changes direction. The rollers 1676 facilitate the movement of the supply substrate 1605 along a substrate path from the substrate supply roll 1602 to the roll 1607, around which an intermediate substrate is wound to form an intermediate substrate roll. As used herein, a substrate supply roll is a roll of the supply substrate 1605 before alignment features are formed thereon, which can be wound around the substrate supply roll 1602, and an intermediate substrate roll is a roll of the supply substrate 1605 after alignment features are formed, which can be wound around the roll 1607.

[0189] Device 1600D further includes a template 1672 (e.g., a conformal roll template), which can be a closed or continuous or continuous loop formed of a flexible material having an imprint template pattern on its surface. Preferably, the roll 1674 supports, moves the template 1672 and provides tension to the template 1672. Thus, the roll 1674 defines a closed template path or travel loop for the template 1672. In some embodiments, the template 1672 may include a repeating template pattern similar to the template pattern on the surface of the CRT drum 1665 in Figure 18B and 18C . It will be understood that the template path converges or is directly adjacent to a portion of the substrate path, and the pattern can be transferred from the template 1672 to the substrate 1605 at the location where the two paths coincide (the imprinted portion of the template path).

[0190] The closed-loop template 1672 can advantageously provide advantages over a CRT reel arrangement. For example, it will be understood that a CRT reel may have a template wound around its surface, where the ends of the template are formed on a sheet of material having ends spliced together on the reel. At the point of end splicing, there may be an overlap between these ends. undesirably, due to, for example, the height difference between the overlap and other areas of the template, this overlap does not provide acceptable imprinting results. Thus, the overlap undesirably reduces the yield and / or throughput of the lens structures formed in the substrate 1605. Advantageously, although the template 1672 may also have an overlap region, the length of the template ring 1672 is generally longer than the circumference of the CRT reel. As a result, the percentage of the template 1672 occupied by the overlap is less than the percentage of the overlap region of the CRT reel. This can increase the yield and / or throughput relative to a typical CRT reel. Additionally, in some embodiments, the length of the template 1672 can be increased as needed by appropriately lengthening and / or routing the template 1672 along the path defined by the roller 1674. It will be understood that the length of the template associated with a CRT reel is not easily manipulated as it depends on the size of the reel. Additionally, as Figure 18B and 18C shown, the CRT reel 1665 contacts the substrate along its curved surface, which may tend to change the tension at different contact points with the substrate and, because the reel surface is curved, does not provide the same high fidelity for transferring the imprint pattern as contact along the flat area provided by the template 1672.

[0191] Continuing to refer Figure 18D , at least one deposition device 1660 is disposed above the supply substrate 1605 and / or the conformal roll template 1672. Similar to the deposition devices 1660 of Figure 18B and 18C , the deposition device 1660 can be any suitable device for depositing material onto one or both of the conformal roll template 1672 and the supply substrate 1605, such as an inkjet printer, a slot die, etc. In some embodiments, the deposited material can be a selectively definable material, such as an imprint resist. Preferably, the supply substrate 1605 and the template 1672 travel in the same direction at the same speed along at least a portion of their paths through the device 1600D. In some embodiments, adjacent portions of the paths of the supply substrate 1605 and the template 1672 are located downstream of the deposition device 1660 such that the deposited material can be imprinted by the template features of the conformal roll template 1672. An energy source 1670 (e.g., a light source such as an ultraviolet light source) is disposed along the adjacent portions and cures the imprint material such that a negative of the features of the template 1672 surface is retained on the supply substrate 1605 as one or more alignment features, which is different from after contact with the CRT reel 1665 in Figure 18B and 18CSimilar to those depicted in. In some embodiments, the adjacent portions are preferably linear portions showing the paths of the display substrate 1605 such that when the deposited material is imprinted and cured, both the conformal roll template 1672 and the supply substrate 1605 are substantially flat. The negatively toned imprinting and curing on the supply substrate 1605 produces an intermediate substrate. Then, before rolling up the intermediate substrate on the roller 1607 to complete the first part of the roll-to-roll manufacturing process, the imprinted side of the intermediate substrate can be covered with a protective film 1608.

[0192] Reference Figure 18E , the second part of the roll-to-roll manufacturing process can be used to form a wave plate layer on the intermediate substrate to produce a finished lens substrate 1650. The device 1600E is configured to receive the intermediate substrate, which in some embodiments is formed using the device 1600D. In some embodiments, the device 1600E can be located at a different position from the device 1600D, and the intermediate substrate can be transported to the location of the device 1600E in the form of a roll to be converted into the lens substrate 1650. In the device 1600E, the intermediate substrate can be unrolled at the intermediate substrate roller 1607'. During this unrolling, any protective film 1608 can also be removed. Similar to Figures 18A - 18C the process described in, after removing the protective film 1608 from the intermediate substrate, the first wave plate lens layer 1632 can be deposited by a first wave plate lens layer dispenser 1615 (e.g., a slot die) and then the first wave plate lens layer 1632 can be cured using a heat source 1637 (e.g., an oven) and / or a light source 1635 (e.g., a UV light source). Similarly, the second wave plate lens layer can be deposited by a second wave plate lens layer dispenser 1640 (e.g., a second slot die), and then the second wave plate lens layer can be cured using a second heat source 1647 (e.g., a second oven) and / or a second light source 1645 (e.g., a second UV light source). The resulting lens substrate 1650 can be rolled onto the lens substrate roller 1655. In some embodiments, another protective film 1652 can be applied on one or both sides of the lens substrate 1650 to protect the surface and structure of the lens substrate 1650 during the handling of the lens substrate roller 1655.

[0193] Figure 19A and 19B show other example systems for fabricating lens substrates for adaptive lens assemblies for sheet materials. Similar to the Figures 18A - 18E configuration of, the systems 1700A and 1700B are configured to apply one or more thin wave plate lens layers, such as liquid crystal polymer wave plate lens layers, onto a supply substrate to form a lens substrate. Figure 19A and 19B The processes applied in respectively correspond to Figures 18A - 18EThe processes applied in [the system]. Systems 1700A and 1700B differ from devices 1600A, 1600B, 1600C, 1600D, and 1600E mainly in that systems 1700A and 1700B are configured for sheet-based manufacturing processes rather than the roll-to-roll manufacturing process described in reference to Figures 18A - 18E For example, a substrate sheet 1705 rather than a roll can be used for processing. In various embodiments, the sheet can be square or rectangular and have dimensions between 6” and 36” on each side.

[0194] System 1700A receives a supply substrate sheet 1705, which can be, for example, a quarter-wave plate substrate of a wire mesh or other array having a conductive material formed on one side of the substrate. System 1700A includes an optical aligner 1710, an alignment layer applicator 1715, a first waveplate lens layer applicator 1720, a second waveplate lens layer applicator 1725, a UV light source 1730, and an oven 1735, which can be similar to Figure 18A the deposition and curing devices of device 1600A in [the reference]. The alignment layer applicator 1715 and the waveplate lens layer applicators 1720, 1725 can each include a slot die and / or other mechanisms for depositing a material layer onto the supply substrate sheet 1705. The supply substrate sheet 1705 travels along a processing path 1707 through other components of system 1700A. The optical aligner 1710 is configured to travel along an axis 1712 transverse to the processing path 1707 such that the optical aligner can apply one or more alignment structures to the supply substrate sheet 1705 and / or the alignment layer material 1715 by lithography, direct writing methods, holographic recording, or other optical processes. In some embodiments, the optical aligner 1710 can apply the alignment structure when the supply substrate sheet 1705 is in a fixed position that at least partially intersects the axis 1712.

[0195] Figure 19B System 1700B of [the reference] employs a sheet processing method similar to that shown in Figure 19A System 1700B is configured to receive a supply substrate sheet 1705 that has been previously prepared with alignment features 1708. For example, it can be done by a method similar to that in reference to Figure 18BA jetting and flashing process similar to the described imprint alignment process is used to apply the alignment structure 1708 (involving the deposition of a resist layer and patterning the resist layer by imprinting to form the alignment structure 1708). It will be understood that the alignment structure 1708 is schematically represented and may have any other shape and more complex arrangement compared to the depicted features. Examples of alignment structures are disclosed in U.S. Provisional Patent Application No. 62 / 424,341 filed on November 18, 2016 and U.S. Provisional Patent Application No. 62 / 518,539 filed on June 12, 2017, the entire contents of which are incorporated herein by reference. Thus, the alignment feature 1708 can at least partially determine the orientation of the crystals in the liquid crystal polymer applied by the first waveplate lens layer applicator 1720.

[0196] Figure 20A and 20B FIGS. show an example system for spin-coating a lens substrate for an adaptive lens subassembly. Similar to Figure 19A and 19B systems 1700A and 1700B, systems 2000A and 2000B are configured to apply one or more thin waveplate lens layers, such as liquid crystal waveplate lens layers, to discrete portions of a supply substrate to form a lens substrate. Figure 20A and 20B The processes applied in Figure 19A and 19B correspond to the processes applied in Figure 19A and 19B respectively. The main difference between systems 2000A and 2000B and systems 1700A and 1700B is that systems 2000A and 2000B are configured to form the waveplate lens layer on a substantially circular supply substrate 2005 rather than on the rectangular supply substrate sheet 1705 depicted in

[0197] System 2000A receives a supply substrate 2005, which can be, for example, a quarter-waveplate substrate having a conductive material screen or other array previously formed on one side of the substrate 2005. Similar to Figure 19AIn the system 1700A, the system 2000A includes an optical aligner 2010, an alignment layer applicator 2015, a first waveplate lens layer applicator 2020, a second waveplate lens layer applicator 2025, a UV light source 2030, and an oven 2035, some or all of which may be located on a frame 2040. The frame is movable along a frame axis 2042 such that the frame 2040 can travel partially or completely over a rotating supply substrate wafer 2005 to any of various positions. The optical aligner 2010 can be configured to travel along an alignment axis 2012 on the frame 2040. The alignment layer applicator 1715 and the waveplate lens layer applicators 1720, 1725 can each include a dispensing mechanism configured to deposit a portion of a liquid material. For example, the dispensing mechanism can be a spin coating deposition device. In some embodiments, the dispensing mechanism can apply the liquid material to the center of the supply substrate wafer 2005 such that rotation of the supply substrate 2005 causes the liquid to be radially distributed outwardly over the surface of the supply substrate wafer 2005 by centrifugal force.

[0198] As the frame 2040 passes over the wafer 2005 along the frame axis 2042, the supply substrate wafer 2005 is rotated about the center of the substrate 2005. In some embodiments, the frame 2040 can pass over the supply substrate wafer 2005 several times. For example, during a first pass, the alignment layer applicator 2015 can apply a liquid alignment layer that is distributed by centrifugal force and cured as the UV light source 2030 and / or the oven 2035 pass over the wafer 2005. Then, before the waveplate lens layers are applied by the first and second waveplate lens layer applicators 2020, 2025, the optical aligner 2010 can pass over the wafer 2005 to optically generate one or more alignment structures within the alignment layer. It will be understood that each of the alignment and waveplate lens layers can be deposited by spin coating, by depositing material toward the center of the substrate 2005, and by spinning the substrate to distribute the material over the substrate.

[0199] Figure 20B The system 2000B of Figure 20A employs a similar sheet handling method as shown in Figure 19B . The system 2000B is configured to receive a supply substrate wafer 2005 that has been prepared with alignment features 2008, which can be similar to the alignment features 1708 of Figure 20AOne or more waveplate lens layer applicators 2020, 2025 as described form one or more waveplate lenses on the alignment feature 2008.

[0200] Common reference Figures 18A - 20B , each of the devices, systems, and methods described can produce rolls or sheets of lens substrates that are larger and / or of a different shape than the adaptive lens assemblies (e.g., adaptive lens assemblies 1004, 1008 as Figure 10 shown) that will be incorporated into a display device. For example, a roll or sheet of lens substrates can contain enough lens substrate to form multiple adaptive lens assemblies or sub-assemblies. Thus, at some point during the manufacturing process, the adaptive lens assemblies, sub-assemblies, and / or substrates can be divided, shaped, and / or segmented. In one example, a roll of lens substrate can be cut into sheets. Cell walls (e.g., cell wall 1418 as Figure 17C and 17D shown) can be printed onto the sheets in the desired shape of the adaptive lens assemblies. Then, liquid crystal can be added, along with quarter-waveplate substrates that adhere to the cell walls as described herein, to form sheets of adaptive lens sub-assemblies. Alternatively, before adding the liquid crystal, portions of the substrate can be divided into lens substrates for individual adaptive lens sub-assemblies. If sheets of adaptive lens sub-assemblies are formed, then the sheets can be divided into individual adaptive lens sub-assemblies, which can then be combined into multiple layers to form a complete adaptive lens assembly.

[0201] Method for forming a wiring screen and an electrode pattern

[0202] As described above, various methods can be employed to form the electrode patterns or meshes 1420 disclosed herein.

[0203] Figures 21A - 21C An example of a process for forming a pattern of a conductive material by directional etching is shown. A metal layer 1420 is deposited on a substrate 1416, and a resist layer 2100 is deposited (e.g., by inkjet deposition) on the metal layer 1420. Subsequently, the resist layer 2100 is patterned (e.g., by imprinting and then hardened by UV exposure). Then, the patterned resist layer 2100 can be used as a mask for directional or anisotropic etching of the underlying metal layer to define the patterned conductive feature 1420, which can be an electrode as disclosed herein. It will be understood that the substrate 1416 can correspond to the substrates 1605, 1705, 2005 discussed with reference to the various figures herein.

[0204] Figures 22A - 22CAn example of a process for forming a pattern of a conductive material using a solvent - soluble “lift - off” layer is shown. A solvent - soluble layer 2102 is deposited on a substrate 1416, and a resist layer 2100 is deposited on the solvent - soluble layer 2102 (e.g., by ink - jet deposition). The resist layer 2100 is then patterned (e.g., by imprinting and then hardened by UV exposure). The patterned resist layer 2100 can include a pattern of openings 2101a and can be used as a mask for wet - etching the underlying solvent - soluble layer 2102, thereby opening volumes into which a metal (e.g., silver) is deposited using blanket deposition, as Figure 22B shown. It will be understood that blanket deposition can include chemical vapor deposition (CVD or AP - CVD), physical vapor deposition (PVD), slot - die deposition, ink - jet printing, blade deposition, etc. In some embodiments, the solvent - soluble layer is formed of a water - soluble material, and the wet - etching includes exposure to water. In some other embodiments, the solvent - soluble layer is formed of PMMA, and the wet - etching includes exposure to acetone or toluene. After the metal deposition, referring to Figure 22C , the entire structure is again exposed to the solvent, which causes the solvent - soluble layer 2102 to be removed or easily lifted off, leaving the deposited metal to retain the pattern indicated by the original patterned resist layer 2100.

[0205] Figures 23A - 23C An example of a process for forming a pattern of a conductive material using a seed layer is shown. A resist layer 2100 is deposited on a substrate 1416 (e.g., by ink - jet deposition), and a solvent - soluble layer 2102 is deposited on the resist layer 2100. The resist layer 2100 and the solvent - soluble layer 2102 are patterned (e.g., by imprinting and then hardened by UV exposure) and have a shared open volume 2101a. A conductive seed layer (e.g., a metal layer) is deposited by blanket deposition (e.g., by CVD or PVD) over the entire structure. Subsequently, the solvent - soluble layer 2102 is exposed to the solvent, allowing portions of the seed layer 2104’ that cover the solvent - soluble layer 2102 to be removed. Then, a conductive metal is selectively deposited in the openings 2101a, e.g., by electroplating.

[0206] Figures 24A - 24C Another example of a process for forming a pattern of a conductive material using a seed layer is shown. A conductive seed layer 2104 is deposited on a substrate 1416 (e.g., by CVD or PVD), and a resist layer 2100 is deposited on the seed layer 2104. The resist layer 2100 is patterned (e.g., by imprinting and then hardened by UV exposure) to define, for example, a volume 2101a. The volume 2101a can be extended downward to expose the seed layer 2104, e.g., by using anisotropic etching selective to the material forming the resist layer 2100. Then, a conductive metal is selectively deposited in the openings 2101a, e.g., by electroplating.

[0207] Figures 25A - 25C An example of a process for forming a pattern of a conductive material by depositing a suspension of a metallic material into openings of a patterned layer is shown. A resist layer 2100 is deposited (e.g., by CVD or PVD) on a substrate 1416 and patterned (e.g., by imprinting and subsequent hardening by UV exposure) to define, for example, a volume 2101a. A solution or suspension 1420” containing metal is then deposited into the opening 2101a, for example, by inkjet deposition, slot die deposition, etc. The liquid in the suspension or solution can then be removed, for example, by exposure to heat (e.g., sintering), to leave metal in the opening. In some embodiments, the solution or suspension 1420” can be exposed to timed wet or dry etching to remove a top portion of the deposited metal-containing layer extending over the opening 2101a, and the solution or suspension 1420” can alternatively not be exposed to heat to drive off the liquid from the solution or suspension. In some embodiments, the resist 2100 can then be removed. In some other embodiments, the resist can be retained to provide additional mechanical and structural stability.

[0208] Figures 26A - 26F An example of a top view of a pattern of a conductive material is shown. In some embodiments, Figures 26A - 26F the conductive material 1420 in each of Figures 21A - 25C can be formed by the method described above with reference to Figure 26A . Generally, the conductive material 1420 can be arranged along the substrate in various shapes, patterns, paths, and / or orientations. In some embodiments, the arrangement of the conductive material 1420 can be selected to provide a sufficiently uniform electric field on a liquid crystal material disposed adjacent to the substrate. In various non-limiting examples, the arrangement of the conductive material 1420 can include a square or rectangular array (e.g., Figure 26B ), an array of parallel wirings connected by one or more lateral wirings (e.g., Figure 26C ), non-overlapping serpentine wirings (e.g., Figure 26D ), multiple overlapping serpentine wirings (e.g., Figure 26E ), a generally spiral-shaped wiring (e.g., Figure 26F ), a parallelogram array (e.g., ), or various other arrangements of straight and / or curved elongated material wirings. Endpoints of the various wirings of the conductive material 1420 can be in contact with other circuits configured to selectively apply a voltage difference across the conductive material 1420 to generate an electric field.

[0209] Figures 27A - 27D Now referring to Figures 27A - 27D

[0209] The methods and layers depicted, for example, can be used to form various shapes and / or layers of conductive material 1420 or other materials. For example, additional layers can be used to form an anti-reflection coating. For example, a capping material layer 1421 (e.g., an optically transmissive material) can be applied over at least a portion of the conductive material 1421. The thickness of the capping material 1421 can be selected to allow the capping material 1421 to function as an anti-reflection coating to provide, for example, destructive interference at a desired wavelength range.

[0210] As Figure 27A shown, in some embodiments, the conductive material 1420 can be applied in a desired shape by angled deposition. In Figure 27A FIG. 21, the pattern layer 2100 includes a plurality of features that protrude away from the substrates 1416, 1605, 1705, 2005. Angled deposition of the conductive material 1420, such as silver, can result in a configuration where one side of the protruding features is substantially covered while other portions of the pattern layer 2100 remain exposed to provide, for example, a relatively large cross-sectional area for current flow.

[0211] As Figure 27B shown, the capping material 1421 can be applied over the layer of the conductive material 1420. For example, the capping material 1421 can be an additional metal such as chromium, an ionic compound such as MgF2, SiO2, TiO2, or any other capping material that can be deposited over the conductive material 1420 and provide the desired electrical and / or optical properties. Figure 27C FIG. 22 depicts an arrangement Figure 27B similar to FIG. 21, where an additional seed layer 2104 or adhesion layer is provided between the conductive material 1420 and the substrates 1416, 1605, 1705, 2005. For example, a seed layer can be left behind during the process of forming the conductive material 1420 using Figures 23A - 24C FIG. 23. As Figure 27D shown, the conductive material 1420 can be formed in various shapes on the substrates 1416, 1605, 1705, 2005. For example, the cross-sectional profile of the conductive material 1420 can be a rectangular profile 1420a, a triangular profile 1420b, a circular profile 1420c, a trapezoidal profile 1420d, or any other desired profile shape.

[0212] Other Considerations

[0213] In the foregoing specification, the invention has been described with reference to specific embodiments of the invention. However, it is apparent that various modifications and changes can be made thereto without departing from the broader spirit and scope of the invention. The specification and drawings are accordingly to be regarded as illustrative rather than restrictive.

[0214] In fact, it will be understood that each of the systems and methods of the present disclosure has several innovative aspects, none of which is solely responsible for or essential to the desired attributes disclosed herein. The various features and methods described above may be used independently of each other or may be combined in various ways. All possible combinations and sub-combinations will fall within the scope of the present disclosure.

[0215] Specific features described in the context of separate embodiments in this specification may also be implemented in combination in a single embodiment. Conversely, the various features described in the context of a single embodiment may also be implemented separately in multiple embodiments or in any suitable sub-combination. Additionally, although features may be described above as acting in a particular combination and even initially claimed as such, one or more features from the claimed combination may in some cases be removed from the combination, and the claimed combination may be directed to a sub-combination or variation of a sub-combination. For each embodiment, a single feature or group of features is not necessary or essential.

[0216] It will be understood that conditional language used herein, e.g., "can", "could", "might", "may", "such as", etc., unless specifically stated otherwise or otherwise understood in the context in which it is used, is generally intended to convey that certain embodiments include, while other embodiments do not include, certain features, elements, and / or steps. Thus, such conditional language is not generally intended to imply that one or more embodiments require, in any way, any features, elements, and / or steps, or that one or more embodiments necessarily include logic for determining, with or without author input or prompting, whether such features, elements, and / or steps are included or performed in any particular embodiment. The terms "comprising", "including", "having", etc. are synonyms and are used inclusively in an open-ended manner and do not exclude additional elements, features, acts, operations, etc. Further, the term "or" is used in its inclusive sense (and not in its exclusive sense) such that when used, for example, to connect a list of elements, the term "or" means one, some, or all of the elements in the list. Additionally, unless otherwise specified, the articles "a", "an", and "the" as used in this application and the appended claims are to be construed as "one or more" or "at least one". Similarly, although operations may be described in a particular order in the figures, it should be recognized that such operations need not be performed in the particular order shown or in sequential order, or that all of the illustrated operations be performed, to achieve the desired result. Further, the figures may schematically depict one or more example processes in the form of a flowchart. However, other operations not shown may be incorporated into the example methods and processes schematically shown. For example, one or more additional operations may be performed before, after, simultaneously with, or between any of the illustrated operations. Additionally, in other embodiments, the operations may be rearranged or reordered. In certain cases, multitasking and parallel processing may be advantageous. Further, the separation of various system components in the above-described embodiments should not be understood to be required in all embodiments, and it will be understood that the described program components and systems can generally be integrated in a single software product or packaged as multiple software products. Additionally, other embodiments are within the scope of the following claims. In certain cases, the acts recited in the claims may be performed in a different order and still achieve the desired result.

[0217] Accordingly, the claims are not intended to be limited to the embodiments shown herein but are to be accorded the broadest scope consistent with the disclosure, the principles and novel features disclosed herein.

Claims

1. A display device, comprising: A waveguide assembly, which includes a waveguide configured to output light for displaying an image; And An adaptive lens assembly having a main surface facing the main surface of the waveguide, the adaptive lens assembly comprising: A waveplate lens; and A switchable waveplate assembly, which includes: A first quarter-wave plate and a second quarter-wave plate that define a volume therebetween, wherein each of the first quarter-wave plate and the second quarter-wave plate includes a flexible material suitable for roll-to-roll manufacturing of the adaptive lens assembly; and A liquid crystal layer disposed in the volume between the first quarter-wave plate and the second quarter-wave plate, wherein the volume is substantially filled with the liquid crystal layer and substantially no air is retained in the volume, wherein each of the first quarter-wave plate and the second quarter-wave plate is configured to serve both as an optical element of the adaptive lens assembly and as a support substrate, and the adaptive lens assembly does not have an additional support substrate, and wherein the liquid crystal molecules of the liquid crystal layer have selectively switchable orientations.

2. The display device according to claim 1, wherein, The switchable waveplate assembly further includes: an electrode pattern disposed in the volume between the first quarter-wave plate and the second quarter-wave plate, the electrode pattern including a conductive material configured to selectively establish an electric field to change the orientation of the liquid crystal molecules.

3. The display device according to claim 2, wherein, The electrode pattern is disposed on the first quarter-wave plate, and another electrode pattern is disposed in the volume on the second quarter-wave plate.

4. The display device according to claim 1, wherein, The waveplate lens includes a liquid crystal polymer layer.

5. The display device according to claim 4, wherein, The adaptive lens assembly further includes an alignment layer disposed between the waveplate lens and the first quarter-wave plate, wherein the alignment layer at least partially determines the orientation of the liquid crystal molecules in the liquid crystal polymer layer.

6. The display device according to claim 4, wherein, The waveplate lens includes another liquid crystal polymer layer on the liquid crystal polymer layer.

7. The display device according to claim 1, wherein, The volume between the first quarter-wave plate and the second quarter-wave plate is further defined by a cell wall extending between the first quarter-wave plate and the second quarter-wave plate, wherein the cell wall includes an inkjet-printable material.

8. The display device according to claim 1, wherein, The waveplate lens and the switchable waveplate assembly constitute an adaptive lens sub-assembly, wherein the adaptive lens assembly includes a plurality of adaptive lens sub-assemblies, and each adaptive lens sub-assembly includes: A waveplate lens; and A switchable waveplate assembly.

9. The display device according to claim 1, further comprising another adaptive lens assembly on a side of the waveguide assembly opposite to the adaptive lens assembly, wherein the another adaptive lens assembly includes an associated waveplate lens and an associated switchable waveplate assembly.

10. An adaptive lens assembly, comprising: A waveplate lens; And A switchable waveplate assembly, which includes: A first quarter-wave plate and a second quarter-wave plate that define a volume therebetween, wherein each of the first quarter-wave plate and the second quarter-wave plate includes a flexible material suitable for roll-to-roll manufacturing of the adaptive lens assembly; and A liquid crystal layer in the volume disposed between the first quarter-wave plate and the second quarter-wave plate, wherein the volume is substantially filled with the liquid crystal layer and substantially no air is retained in the volume, wherein each of the first quarter-wave plate and the second quarter-wave plate is configured to serve both as an optical element of the adaptive lens assembly and as a support substrate, and the adaptive lens assembly does not have an additional support substrate, and wherein the liquid crystal molecules of the liquid crystal layer have a selectively switchable orientation.

11. The adaptive lens assembly according to claim 10, wherein, The switchable wave plate assembly further includes: an electrode pattern in the volume disposed between the first quarter-wave plate and the second quarter-wave plate, the electrode pattern including a conductive material configured to selectively establish an electric field to change the orientation of the liquid crystal molecules.

12. The adaptive lens assembly according to claim 11, wherein, The electrode pattern is disposed on the first quarter-wave plate, and another electrode pattern is disposed in the volume on the second quarter-wave plate.

13. The adaptive lens assembly according to claim 10, wherein, The wave plate lens includes a liquid crystal polymer layer.

14. The adaptive lens assembly according to claim 13, wherein, The adaptive lens assembly further includes an alignment layer disposed between the wave plate lens and the first quarter-wave plate, wherein the alignment layer at least partially determines the orientation of the liquid crystal molecules in the liquid crystal polymer layer.

15. The adaptive lens assembly according to claim 13, wherein, The wave plate lens includes another liquid crystal polymer layer on the liquid crystal polymer layer.

16. The adaptive lens assembly according to claim 10, wherein, The volume between the first quarter-wave plate and the second quarter-wave plate is further defined by a cell wall extending between the first quarter-wave plate and the second quarter-wave plate, wherein the cell wall includes an inkjet-printable material.

17. The adaptive lens assembly according to claim 10, wherein, The wave plate lens and the switchable wave plate assembly constitute an adaptive lens subassembly, wherein the adaptive lens assembly includes a plurality of adaptive lens subassemblies, each adaptive lens subassembly including: A wave plate lens; and A switchable wave plate assembly.

18. A display device, comprising: A waveguide assembly including a waveguide configured to output light to display an image; And An adaptive lens assembly having a main surface facing the main surface of the waveguide, the adaptive lens assembly including: A wave plate lens; and A switchable wave plate assembly, including: A first substrate and a second substrate defining a volume therebetween, wherein each of the first substrate and the second substrate includes a flexible non-liquid crystal material suitable for roll-to-roll manufacturing of the adaptive lens assembly; A liquid crystal layer disposed within the volume; A first set of guides for aligning the liquid crystal molecules of the liquid crystal layer, the first set of guides including a first electrode pattern disposed in the volume and on the first substrate; and A second set of guides for aligning the liquid crystal molecules of the liquid crystal layer, the second set of guides including a second electrode pattern disposed in the volume and on the first substrate; Wherein the first substrate is a first quarter-wave plate and the second substrate is a second quarter-wave plate. Wherein, the volume is substantially filled with the liquid crystal layer and substantially no air is retained in the volume, wherein each of the first quarter-wave plate and the second quarter-wave plate is configured to serve both as an optical element of the adaptive lens assembly and as a support substrate, and the adaptive lens assembly does not have an additional support substrate. Wherein, the first electrode pattern and the second electrode pattern are configured to establish an electric field for selectively changing the orientation of the liquid crystal molecules of the liquid crystal layer.

19. The display device according to claim 18, wherein, At least one of the first electrode pattern and the second electrode pattern includes an array of parallel conductors.

20. The display device according to claim 18, wherein, At least one of the first electrode pattern and the second electrode pattern includes a wire mesh.

21. The display device according to claim 18, wherein, Each of the first substrate and the second substrate includes a quarter-wave plate.

22. The display device according to claim 18, wherein, The wave plate lens and the switchable wave plate assembly constitute an adaptive lens sub-assembly, wherein the adaptive lens assembly includes a plurality of adaptive lens sub-assemblies, and each adaptive lens sub-assembly includes: A wave plate lens; and A switchable wave plate assembly.

23. The display device according to claim 18, further comprising another adaptive lens assembly on a side of the waveguide assembly opposite to the adaptive lens assembly, wherein the another adaptive lens assembly includes an associated wave plate lens and an associated switchable wave plate assembly.

24. An adaptive lens assembly, comprising: A wave plate lens; And A switchable wave plate assembly, which includes: A first substrate and a second substrate that define a volume therebetween, wherein each of the first substrate and the second substrate includes a flexible non-liquid crystal material suitable for roll-to-roll manufacturing of the adaptive lens assembly; A liquid crystal layer disposed in the volume; A first set of guides for aligning the liquid crystal molecules of the liquid crystal layer, the first set of guides including a first electrode pattern disposed in the volume and on the first substrate; and A second set of guides for aligning the liquid crystal molecules of the liquid crystal layer, the second set of guides including a second electrode pattern disposed in the volume and on the first substrate; Wherein, the first substrate is a first quarter-wave plate, and the second substrate is a second quarter-wave plate. Wherein, the volume is substantially filled with the liquid crystal layer and substantially no air is retained in the volume, wherein each of the first quarter-wave plate and the second quarter-wave plate is configured to serve both as an optical element of the adaptive lens assembly and as a support substrate, and the adaptive lens assembly does not have an additional support substrate. Wherein, the first electrode pattern and the second electrode pattern are configured to establish an electric field for selectively changing the orientation of the liquid crystal molecules of the liquid crystal layer.

25. The adaptive lens assembly according to claim 24, wherein, At least one of the first electrode pattern and the second electrode pattern includes an array of parallel conductors.

26. The adaptive lens assembly according to claim 24, wherein, At least one of the first electrode pattern and the second electrode pattern includes a wire mesh.

27. The adaptive lens assembly according to claim 24, wherein, Each of the first substrate and the second substrate includes a quarter-wave plate.

28. The adaptive lens assembly according to claim 24, wherein, The wave plate lens includes a liquid crystal polymer layer.

29. The adaptive lens assembly according to claim 28, wherein, The adaptive lens assembly further includes an alignment layer disposed between the waveplate lens and the first quarter-wave plate, wherein the alignment layer at least partially determines the orientation of the liquid crystal molecules in the liquid crystal polymer layer.

30. The adaptive lens assembly according to claim 28, wherein, The waveplate lens includes another liquid crystal polymer layer on the liquid crystal polymer layer.

31. The adaptive lens assembly according to claim 24, wherein, The waveplate lens and the switchable waveplate assembly constitute an adaptive lens subassembly, wherein the adaptive lens assembly includes a plurality of adaptive lens subassemblies, and each adaptive lens subassembly includes: a waveplate lens; and a switchable waveplate assembly.

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