Systems and methods for ambient light management

Abstract

To provide an augmented reality system.SOLUTION: An augmented reality system includes a light source to generate a virtual light beam, the virtual light beam carrying information on a virtual object. The system also includes a light guiding optical element, the light guiding optical element allowing a first portion of a first real-world light beam to pass therethrough, where the virtual light beam enters the light guiding optical element, propagates through the light guiding optical element by substantially total internal reflection (TIR), and exits the light guiding optical element. The system further includes a lens disposed adjacently to the light guiding optical element and exterior to a surface thereof, the lens comprising a light modulating mechanism to absorb a second portion of the real-world light beam and to allow the first portion of the real-world light to pass through the lens.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application claims priority to U.S. Provisional Patent Application No. 62 / 731,755, filed on September 14, 2018, entitled "SYSTEMS AND METHODS FOR EXTERNAL LIGHT MANAGEMENT", which is hereby incorporated by reference in its entirety as if fully set forth herein. This application is related to U.S. Patent Application No. 15 / 479,700, filed on April 5, 2017, under Attorney Docket No. ML.20065.00, entitled "SYSTEM AND METHOD FOR AUGMENTED REALITY"; U.S. Patent Application No. 14 / 331,218, filed on July 14, 2014, under Attorney Docket No. ML.20020.00, entitled "PLANAR WAVEGUIDE APPARATUS WITH DIFFRACTION ELEMENT(S) AND SYSTEM EMPLOYING SAME"; U.S. Patent Application No. 14 / 555,585, filed on November 27, 2014, under Attorney Docket No. ML.20011.00, entitled "VIRTUAL AND AUGMENTED REALITY SYSTEMS AND METHODS"; U.S. Patent Application No. 14 / 726,424, filed on May 29, 2015, under Attorney Docket No. ML.20016.00, entitled "METHODS AND SYSTEMS FOR VIRTUAL AND AUGMENTED REALITY"; U.S. Patent Application No. 14 / 726,429, filed on May 29, 2015, under Attorney Docket No. ML.20017.00, entitled "METHODS AND SYSTEMS FOR CREATING FOCAL PLANES IN VIRTUAL AND AUGMENTED REALITY".This application is related to U.S. Patent Application No. 14 / 726,396, filed May 29, 2015 under Attorney Docket No. ML-0676USPRV and entitled "METHODS AND SYSTEMS FOR DISPLAYING STEREOSCOPY WITH A FREEFORM OPTICAL SYSTEM WITH ADDRESSABLE FOCUS FOR VIRTUAL AND AUGMENTED REALITY," U.S. Provisional Patent Application No. 62 / 702,212, filed July 23, 2018 under Attorney Docket No. ML-0676USPRV and entitled "SYSTEMS AND METHODS FOR EXTERNAL LIGHT MANAGEMENT," and U.S. Patent Application No. 16 / 557,706, filed August 30, 2019 under Attorney Docket No. ML-0607US and entitled "SPATIALLY-RESOLVED DYNAMIC DIMMING FOR AUGMENTED REALITY DEVICE." The contents of the aforementioned patent applications are expressly and completely incorporated herein by reference in their entirety as if fully set forth. [Background technology]

[0002] Modern computing and display technologies have facilitated the development of systems for so-called "augmented reality" experiences, in which digitally reproduced images, or portions thereof, are presented to a user in a manner that appears or can be perceived as real. Augmented reality, or "AR," scenarios typically involve the presentation of digital or virtual image information as an extension to the visualization of the real world around the user (i.e., transparent to other actual real-world visual input). Thus, AR scenarios involve the presentation of digital or virtual image information with transparency to other actual real-world visual input. The human visual perception system is highly complex, making it difficult to produce AR technologies that facilitate a comfortable, natural-feeling, and rich presentation of virtual image elements among other virtual or real-world image elements.

[0003] The brain's visual centers derive useful perceptual information from the relative movement of the eyes and their components. The relative movement of the eyes (i.e., the rotation of the pupils toward or away from each other to converge the gaze of the eyes and fixate on an object) is closely linked to the focusing of the eye's lenses (or "accommodation"). Under normal conditions, changing the focus of the eye's lenses, i.e., accommodating the eyes to focus on objects at different distances, will automatically produce a corresponding change in vergence to the same distance, a relationship known as the "accommodation-vergence reflex." Similarly, a change in vergence will also induce a corresponding change in accommodation under normal conditions. Opposing this reflex (as in most conventional stereoscopic AR configurations) is known to cause eye strain, headaches, or other forms of discomfort to users.

[0004] Stereoscopic wearable glasses generally feature two displays, one for the left and one for the right eye, configured to display images with slightly different element presentations so that a three-dimensional perspective is perceived by the human visual system. Such configurations have been found to be uncomfortable for many users due to a mismatch between vergence and accommodation (the "vergence-accommodation conflict") that must be overcome to perceive images in three dimensions. In fact, some AR users are unable to tolerate stereoscopic configurations. Thus, most conventional AR systems are not optimally suited to presenting a rich, binocular three-dimensional experience in a manner that would be comfortable and maximally useful to users, in part because conventional systems fail to address some fundamental aspects of the human perceptual system, including vergence-accommodation conflict.

[0005] The AR system must also be able to display virtual digital content at various perceived positions and distances relative to the user. The design of the AR system also presents a number of other challenges, including the speed of the system when delivering virtual digital content, the quality of the virtual digital content, the user's exit pupil distance (to address vergence-accommodation conflict), the size and portability of the system, and other system and optical issues.

[0006] One possible approach to addressing these problems (including vergence-accommodation conflict) is to project the image onto multiple depth planes. To implement this type of system, one approach is to use multiple light-guiding optical elements to direct light into the user's eye such that the light appears to originate from multiple depth planes. The light-guiding optical elements are designed to internally couple virtual light corresponding to a digital or virtual object, propagate it by total internal reflection ("TIR"), and then externally couple the virtual light to display the digital or virtual object to the user's eye. The light-guiding optical elements are also designed to be transmissive to light from actual real-world objects (e.g., reflected therefrom).

[0007] However, some real-world light can be internally coupled into the light-guiding optical elements and externally coupled in an uncontrolled manner, resulting in unintended rainbow artifacts being presented to the user's eye as a result of the real-world light being diffracted by the light-guiding optical elements. The appearance of unintended rainbow artifacts in an AR scenario can interfere with the intended effect of the AR scenario. The systems and methods described herein are configured to address these challenges. SUMMARY OF THE INVENTION MEANS FOR SOLVING THE PROBLEM

[0008] In one embodiment, the augmented reality system includes a light source configured to generate a virtual light beam, where the virtual light beam carries information about a virtual object. The system also includes a light guiding optical element that is transparent to a first real-world light beam, and the virtual light beam is incident on the light guiding optical element and propagates through the light guiding optical element by total internal reflection (TIR) and exits the light guiding optical element. Additionally, the system also includes a lens disposed adjacent to the light guiding optical element and outside its surface, and the lens is configured with a coloring that absorbs a certain amount of real-world light and allows a portion of the real-world light to transmit through the light guiding optical element.

[0009] In one or more embodiments, the coloring is a gradient coloring that allows little real-world light to transmit through the upper world-side portion of the lens and more real-world light to transmit through the lower world-side portion of the lens, minimizing rainbow artifacts generated from accidental diffraction of real-world light from above by the light guiding optical element.

[0010] In one or more embodiments, the gradient coloring gradually allows more real-world light to transmit from the upper world-side portion of the lens to the lower world-side portion of the lens. The first transmittance average (T avg ) at the upper edge of the lens is 5%, the second T avg at the central portion of the lens is 28%, the third T avg at the bottom portion of the lens is consistently 33% across the bottom portion, and the amount of real-world light transmitted through the lens with gradient coloring is represented as T avg . The lens provides a protective element to the light guiding optical element.

[0011] In one or more embodiments, the lens further includes a deflector disposed adjacent thereto, and the deflector is configured to modify the optical path of a second real-world light beam at the surface of the lens, where the second real-world light beam originates from an overhead position relative to the upper world side.

[0012] In one or more embodiments, the lens is configured with a deflector and gradient coloring, and the combination of the deflector and gradient coloring minimizes a rainbow effect generated from an accidental diffraction of a second real-world light beam by the light guiding optical element.

[0013] In one or more embodiments, the deflector is configured to reflect a second real-world light beam.

[0014] In one or more embodiments, the deflector is configured to refract or diffract a second real-world light beam.

[0015] In one or more embodiments, the lens further comprises orientation markings that are used to mount the lens on an eyeglass frame during assembly. The orientation markings comprise a special ink that renders the orientation markings visible under special illumination during assembly and invisible to the user during normal use.

[0016] In one or more embodiments, the special ink is an infrared ink.

[0017] In one or more embodiments, the special ink is an ultraviolet ink.

[0018] In one or more embodiments, the special ink is not removed after the initial assembly of the lens onto the eyeglass frame, and the lens is reused and reassembled after maintenance operations are completed on the lens or the eyeglass frame.

[0019] In another embodiment, the augmented reality system includes a lens having a flat peripheral surface that is substantially orthogonal to the frame. The system also includes a frame having a flat surface for mounting the flat peripheral surface to the flat surface of the frame, and the lens provides a protective element to the optical elements of the augmented reality system.

[0020] In one or more embodiments, the lens is constructed with Trivex. The center thickness of the lens is 1.2 mm + / - 0.2 mm. The lens has a radius of curvature of 86.8 mm + / - 0.9 mm. The lens comprises at least one of a gradient tint coating, a hard coating, a mirror coating, an anti-fouling coating, and / or an anti-reflection coating.

[0021] In yet another embodiment, the augmented reality system includes a light source for generating a virtual light beam, the virtual light beam carrying information about a virtual object. The system also includes a light guiding optical element that allows a first portion of a first real-world light beam to pass therethrough, the virtual light beam being incident on the light guiding optical element and propagating through the light guiding optical element by total internal reflection (TIR) and exiting the light guiding optical element. The system further includes a lens disposed adjacent to the light guiding optical element and outside its surface, the lens comprising a light modulation mechanism that attenuates a second portion of the real-world light beam and allows the first portion of the real-world light to pass through the lens.

[0022] In one or more embodiments, the light modulation mechanism includes a liquid crystal layer, first and second electrodes disposed adjacent to the liquid crystal layer and on opposite sides thereof, first and second compensation films disposed adjacent to and outside the first and second electrodes respectively, and first and second polarizers disposed adjacent to and outside the first and second compensation films respectively. The first and second polarizers may each include a plurality of regions configured to impart different degrees of polarization to light passing therethrough. The liquid crystal layer may be configured to impart a retardation or a polarization rotation degree to light passing therethrough in response to a voltage applied by the first and second electrodes. The degree of polarization imparted by the liquid crystal layer may be proportional to the voltage applied by the first and second electrodes.

[0023] In one or more embodiments, the first and second electrodes are configured to apply a voltage to the liquid crystal layer that varies along a direction within the liquid crystal layer. The direction may be from the bottom of the liquid crystal layer to the top of the liquid crystal layer. The first and second electrodes may be separated by a distance that increases along the direction within the liquid crystal layer. The first electrode may taper away from the second electrode such that the distance increases along the direction within the liquid crystal layer. The first electrode may include multiple segments, with each adjacent pair of segments having a leading segment that is positioned farther from the second electrode in the direction than the trailing segment. The first electrode may have a thickness that decreases along the direction.

[0024] In one or more embodiments, the first electrode includes first, second, and third segments arranged along a direction, the first and third segments having first and third resistances lower than the second resistance of the second segment. The first and third segments may comprise indium tin oxide. The second segment may comprise graphene. The system may also include first and second voltage sources electrically coupled to the first and third segments of the first electrode.

[0025] In one or more embodiments, the first electrode includes a plurality of segments arranged along the direction and electrically separated from one another by a corresponding plurality of resistors. The system may also include a voltage source electrically coupled to a first segment of the plurality of segments at a distal end of the first electrode along the direction. The first electrode may have a planar shape, and the plurality of resistors may be arranged along an edge of the first electrode. The plurality of segments may be physically separated from one another by a plurality of electrically insulating members. Each of the plurality of resistors may be physically disposed between a respective pair of the plurality of segments.

[0026] In one or more embodiments, the head-mounted device comprises a frame configured to be worn about the head of a user of the head-mounted device, and a controllable dimming assembly physically coupled to the frame such that when the head-mounted device is worn by the user, the controllable dimming assembly is positioned between the user's eyes and the user's environment, the controllable dimming assembly being configured to exhibit a level of opacity that varies from a first level of opacity to a second level of opacity as a function of a location on the controllable dimming assembly, and a control circuitry electrically coupled to the controllable dimming assembly and configured to apply one or more electrical signals to the controllable dimming assembly to adjust one or both of the first and second levels of opacity.

[0027] In some implementations, the controllable dimming assembly is configured to exhibit (i) a first level of opacity at a first location on the controllable dimming assembly and (ii) a level of opacity that varies as a function of the distance from the first location on the controllable dimming assembly. In some of these implementations, the controllable dimming assembly is configured to exhibit a second level of opacity at a second location on the controllable dimming assembly, the second location being different from the first location. In some such implementations, the first location or the second location corresponds to a set of one or more points along at least a portion of the outer perimeter of the controllable dimming assembly. Further, in some such implementations, the first location corresponds to a location within an inner region of the controllable dimming assembly. In some embodiments, the location within the inner region of the controllable dimming assembly corresponds to the center of the controllable dimming assembly.

[0028] In some embodiments, the first level of opacity represents a global minimum level of opacity and the second level of opacity represents a global maximum level of opacity.

[0029] In some implementations, the controllable dimming assembly is configured to exhibit levels of opacity that vary linearly, exponentially, or logarithmically as a function of a location on the controllable dimming assembly.

[0030] In some embodiments, the controllable dimming assembly is configured such that a first level of opacity and a second level of opacity vary based on a level of voltage of one or more electrical signals applied as an input to the controllable dimming assembly.

[0031] In some implementations, the controllable dimming assembly is configured such that a first level of opacity and a second level of opacity change at different rates as the level of voltage changes.

[0032] In some embodiments, the controllable dimming assembly includes a first polarizer and a second polarizer, first and second electrode assemblies disposed between the first polarizer and the second polarizer, and a liquid crystal layer disposed between the first electrode assembly and the second electrode assembly. In some of these embodiments, the control circuitry is electrically coupled to the first and second electrode assemblies and is configured to apply one or more electrical signals to the controllable dimming assembly to produce an electric field between the first electrode assembly and the second electrode assembly.

[0033] Further, in some such embodiments, one or both of the first and second polarizers are configured to impart a spatially varying degree of polarization to light passing therethrough.

[0034] In at least some of these embodiments, to produce an electric field between the first electrode assembly and the second electrode assembly, the controllable dimming assembly is configured to produce an electric field having a spatially varying level of electric field strength between the first electrode assembly and the second electrode assembly.

[0035] In some such embodiments, one or both of the first and second electrode assemblies are configured to spatially vary one or more properties thereof, in some examples, the one or more properties include thickness, resistivity, conductivity, orientation, composition, or a combination thereof.

[0036] In some implementations, the control circuitry comprises one or more of a voltage divider network, conductors, a processor, and a power supply.

[0037] In some embodiments, the controllable dimming assembly is physically coupled to the frame such that when the head-mounted device is worn by a user, it is positioned between the user's eyes and the user's environment.

[0038] In some implementations, the control circuitry is further configured to receive input from one or more data sources and apply one or more electrical signals to the controllable dimming assembly to adjust one or both of the first and second opacity levels, wherein the control circuitry is configured to apply one or more electrical signals to the controllable dimming assembly to adjust one or both of the first and second opacity levels based on the input received from the one or more data sources. In some such implementations, the one or more data sources include one or more sensing devices, user interface components, display system components, network-accessible resources, or combinations thereof. The present invention provides, for example, the following. (Item 1) 1. An augmented reality system, comprising: a light source for generating a virtual light beam, the virtual light beam carrying information about a virtual object; a light guiding optical element, the light guiding optical element allowing a first portion of a first real-world light beam to pass therethrough, the virtual light beam entering the light guiding optical element, propagating through the light guiding optical element by substantially total internal reflection (TIR), and exiting the light guiding optical element; a lens disposed adjacent to and on an exterior surface of the light directing optical element, the lens comprising a light modulation mechanism that attenuates a second portion of the real-world light beam and allows a first portion of the real-world light to pass through the lens; A system comprising: (Item 2) The light modulation mechanism includes: A liquid crystal layer; first and second electrodes disposed adjacent to and on opposite sides of the liquid crystal layer; first and second compensation films disposed adjacent to and external to the first and second electrodes, respectively; first and second polarizers, the first and second polarizers being disposed adjacent to and external to the first and second compensation films, respectively; Item 1. The system of item 1, comprising: (Item 3) Item 3. The system of item 2, wherein the first and second polarizers each include a plurality of regions configured to impart different degrees of polarization onto light passing therethrough. (Item 4) Item 4. The system of item 3, wherein the liquid crystal layer is configured to impart a degree of retardation or polarization rotation onto light passing therethrough in response to a voltage applied by the first and second electrodes. (Item 5) Item 5. The system of item 4, wherein the degree of polarization imparted by the liquid crystal layer is proportional to the voltage applied by the first and second electrodes. (Item 6) Item 3. The system of item 2, wherein the first and second electrodes are configured to apply a voltage to the liquid crystal layer that varies along a direction within the liquid crystal layer. (Item 7) 7. The system of claim 6, wherein the direction is from the bottom of the liquid crystal layer to the top of the liquid crystal layer. (Item 8) The system according to item 6, wherein the first and second electrodes are separated by a distance that increases along the direction in the liquid crystal layer. (Item 9) The system according to item 8, wherein the first electrode is tapered away from the second electrode such that the distance increases along the direction in the liquid crystal layer. (Item 10) The system according to item 8, wherein the first electrode comprises a plurality of segments, and each adjacent pair of segments has a leading segment that is disposed farther from the second electrode than a subsequent segment in the direction. (Item 11) The system according to item 6, wherein the first electrode has a thickness that decreases along the direction. (Item 12) The first electrode comprises first, second, and third segments disposed along the direction, wherein the first and third segments have first and third resistances that are lower than a second resistance of the second segment, The system according to item 6. (Item 13) The system according to item 12, wherein the first and third segments comprise indium tin oxide. (Item 14) The system according to item 12, wherein the second segment comprises graphene. (Item 15) The system according to item 12, further comprising first and second voltage sources electrically coupled to the first and third segments of the first electrode. (Item 16) The system according to item 2, wherein the first electrode comprises a plurality of segments, the plurality of segments are disposed along the direction, and are electrically separated from each other by corresponding resistors. (Item 17) The system according to item 16, further comprising a voltage source electrically coupled to a first segment of the plurality of segments at a distal end of the first electrode along the direction. (Item 18) the first electrode has a flat shape; the plurality of resistors are arranged along an edge of the first electrode; Item 17. The system according to item 16. (Item 19) 20. The system of claim 18, wherein the plurality of segments are physically separated from one another by a plurality of electrically insulating members. (Item 20) Item 17. The system of item 16, wherein each of the plurality of resistors is physically positioned between a respective pair of the plurality of segments. [Brief explanation of the drawings]

[0039] The drawings illustrate the design and utility of various embodiments of the present invention. It should be noted that the drawings are not drawn to scale, and elements of similar structure or function are represented by the same reference numerals throughout the drawings. To better understand how the foregoing and other advantages and objects of the various embodiments of the present invention are obtained, a detailed description of the invention, briefly described above, will be given by reference to specific embodiments thereof that are illustrated in the accompanying drawings. With the understanding that these drawings depict only exemplary embodiments of the invention and therefore should not be considered as limiting its scope, the present invention will be described and explained with additional specificity and detail through the use of the accompanying drawings.

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[0057] Various embodiments of the present invention are directed to systems, methods, and articles of manufacture for implementing optical systems in single or multiple embodiments. Other objects, features, and advantages of the present invention are set forth in the detailed description, drawings, and claims.

[0058] Here, various embodiments will be described in detail with reference to the drawings, which are provided as illustrative examples of the present invention to enable those skilled in the art to practice the present invention. It should be noted that the following figures and examples are not meant to limit the scope of the present invention. If an element of the present invention can be implemented partially or fully using known components (or methods or processes), only those parts of such known components (or methods or processes) necessary for understanding the present invention will be described, and detailed descriptions of other parts of such known components (or methods or processes) will be omitted so as not to obscure the present invention. Further, various embodiments include currently and future known equivalents of the components referenced herein by way of illustration.

[0059] The optical system may be implemented independently of the AR system, but many of the following embodiments will be described in relation to the AR system for illustrative purposes only. (Overview of Problems and Solutions)

[0060] One type of optical system for generating virtual images at various depths while allowing real-world light to pass through includes at least partially transparent light-guiding optical elements (e.g., prisms including diffractive optical elements). However, these light-guiding optical elements can unintentionally internally couple real-world light from real-world light sources. The inadvertently internally coupled real-world light can be diffracted within the light-guiding optical element towards the user's eye. The externally coupled real-world light exits the light-guiding optical element in a diffractive pattern, thereby generating artifacts such as "rainbow" images or artifacts like an artifact in the user's field of view and / or in the vicinity of the virtual object displayed by the light-guiding optical element within the AR scenario. The rainbow artifact hinders the effect of the AR scenario using a discordant image.

[0061] The following disclosure describes various embodiments of systems and methods for creating a 3D perception using multi-planar focal optical elements that address this problem by including an external cover lens ("window") for the light directing optical elements. In particular, the external window has a gradient tint to reduce light (e.g., sunlight, overhead light, etc.) that enters the light directing optical elements from above the user. For example, the gradient tint may allow 5% light transmission at the top portion of the lens and gradually allow more light transmission (e.g., 33%) toward the bottom portion of the lens. The gradient tinted external window is a key component for improving virtual content solidity by reducing the amount of ambient light entering the AR system and for blocking / reducing rainbow artifacts by reducing the amount of overhead light that can inadvertently diffract within the AR system and create "rainbow" artifacts displayed to the user. Gradient coloring allows for a lighting balance between blocking bright overhead light and minimizing rainbow artifacts that appear near virtual content, while allowing enough ambient light (e.g., reflecting off actual real-world objects) to pass through to the AR system, still allowing the user to visibly see and interact with the physical environment.

[0062] The increase in perceived virtual content solidity as a result of the reduction of ambient light unintentionally coupled into and out of light-guiding optical elements may be similar to, for example, the room lighting of a movie theater and the light source behind the display screen in a movie theater environment. For example, as the room lighting inside the movie theater is reduced, the image quality of a movie displayed on the screen may appear enhanced. As another example, if a light source is inadvertently illuminated behind the display screen, the image quality of a movie displayed on the display screen may appear significantly reduced. This reduction in image quality may be due to the light source behind the screen canceling out the image of the movie displayed on the screen. Similarly, the reduction in illumination from overhead real-world light sources while a user is wearing an augmented reality display system is similar to the reduction in room lighting, insofar as it enhances the virtual objects displayed to the user. Furthermore, light sources emanating from the back of a display screen in a theater may be similar to overhead light sources that are inadvertently received and displayed by the augmented reality display system. If overhead lighting is minimized, the impact of rainbow artifacts is correspondingly reduced, while the content realism of virtual objects displayed to the user is enhanced.

[0063] Having a gradient-colored external lens reduces most of the light (e.g., sunlight, overhead light, etc.) that enters the light-guiding optical element from above the user, thereby reducing the diffraction of inadvertently internally coupled light that can diffract within the LOE and produce rainbow artifacts. Since ambient light is generally typically generated from a light source that is above the user of an augmented reality system, more light is reduced in the upper portion of the lens as contrasted with the lower portion of the lens. Examples of typical overhead light sources include sunlight, indoor ceiling lights, outdoor street lights, etc. In other words, most of the light sources for illuminating a room or physical environment are typically generated from above the user. Thus, a window external to the light-guiding optical element can substantially reduce real-world light from above the user and minimize the unintentional internal coupling of real-world light into the light-guiding optical element and the associated rainbow artifacts. At the same time, the gradient of the coloring allows for more light transmittance towards the central portion (e.g., the field of view), and even more light transmittance at the bottom portion of the lens, allowing more ambient light from the physical environment to enter the augmented reality system and enabling the user to interact with the physical environment and virtual objects presented by the AR system.

[0064] The controllable gradient-colored external lens disclosed herein enables the AR system to respond to changes in external light intensity and direction. The AR system can increase the coloring when the external illumination is of relatively high intensity and / or when the external light originates from a high angle (compared to the angle parallel to the optical axis). Controlling the intensity of the coloring enables the AR system to reduce inadvertently internally coupled light and corresponding artifacts while minimizing the impact on external light transmittance in order to improve the AR scenario. (Illustrative Augmented Reality System)

[0065] Before describing the details of an embodiment of a window external to the light-guiding optical element, the present disclosure will here provide a description of an illustrative AR system.

[0066] One possible approach for implementing an AR system is to use multiple volume phase holograms, surface relief holograms, or light guiding optical elements that generate images in which depth plane information is embedded and appears to originate from individual depth planes. In other words, a diffraction pattern, i.e., a diffractive optical element (“DOE”), is embedded within or etched onto a light guiding optical element (“LOE”), e.g., a planar waveguide, such that as collimated light (a light beam with a substantially planar wavefront) is substantially totally internally reflected along the LOE, the diffraction pattern intersects at multiple locations and exits towards the user's eye. The DOE is configured such that the light exiting through it from the LOE touches, and thus appears to originate from, a particular depth plane. The collimated light may be generated using an optical condenser lens (“condenser”).

[0067] For example, a first LOE may be configured to deliver collimated light that appears to originate from an optically infinite depth plane (0 diopters) to the eye. Another LOE may be configured to deliver collimated light that appears to originate from a distance of 2 meters (1 / 2 diopter). Yet another LOE may be configured to deliver collimated light that appears to originate from a distance of 1 meter (1 diopter). By using a stacked LOE assembly, it can be understood that multiple depth planes can be generated and each LOE can be configured to display an image that appears to originate from a particular depth plane. It should be understood that the stack may include any number of LOEs. However, at least N stacked LOEs are required to generate N depth planes. Further, N, 2N, or 3N stacked LOEs may be used to generate an RGB-colored image at N depth planes.

[0068] To present 3D virtual content to a user, an augmented reality (AR) system projects images of the virtual content into the user's eye so that they appear to originate from different depth planes in the Z direction (i.e., orthogonally away from the user's eye). In other words, the virtual content may appear to vary not only in the X and Y directions (i.e., 2D planes orthogonal to the central visual axis of the user's eye) but also in the Z direction, so that the user may perceive objects as being very close, at infinite distance, or any distance in between. In other embodiments, the user may simultaneously perceive multiple objects at different depth planes. For example, the user may see a virtual dragon emerging from infinity and running toward the user. Alternatively, the user may simultaneously see a virtual bird at a distance of 3 meters from the user and a virtual coffee cup at arm's length (approximately 1 meter) from the user.

[0069] A multi-plane focusing system creates the perception of variable depth by projecting images onto some or all of multiple depth planes located at discrete fixed distances in the Z direction from the user's eyes. Referring now to FIG. 4 , it should be understood that a multi-plane focusing system typically displays frames at fixed depth planes 202 (e.g., the six depth planes 202 shown in FIG. 4 ). While an AR system can include any number of depth planes 202, one exemplary multi-plane focusing system has six fixed depth planes 202 in the Z direction. When generating virtual content at one or more of the six depth planes 202, a 3D perception is created such that the user perceives one or more virtual objects at variable distances from the user's eyes. Given that the human eye is more sensitive to objects at closer distances than to objects that appear farther away, more depth planes 202 are generated closer to the eyes, as shown in FIG. 4 . In other embodiments, the depth planes 202 may be positioned equidistant from each other.

[0070] The depth plane position 202 is measured in diopters, which is typically a unit of refractive power equal to the reciprocal of the focal length measured in meters. For example, in one embodiment, depth plane 1 may be separated by 1 / 3 diopter, depth plane 2 may be separated by 0.3 diopter, depth plane 3 may be separated by 0.2 diopter, depth plane 4 may be separated by 0.15 diopter, depth plane 5 may be separated by 0.1 diopter, and depth plane 6 may represent infinity (i.e., 0 diopters away). It should be understood that other embodiments may generate the depth plane 202 at other distances / diopters. Thus, when generating virtual content at a strategically placed depth plane 202, the user can perceive the virtual object in three dimensions. For example, when displayed on depth plane 1, the user can perceive a first virtual object as being near it, while another virtual object appears at infinity in depth plane 6. Alternatively, the virtual object may first be displayed on depth plane 6 and then on depth plane 5 until the virtual object appears very close to the user, and so on. It should be understood that the foregoing examples are greatly simplified for illustrative purposes. In another embodiment, all six depth planes may be concentrated at a specific focal length away from the user. For example, if the virtual content to be displayed is a coffee cup that is 1 / 2 meter away from the user, all six depth planes may be generated at various cross-sections of the coffee cup, providing the user with a very fine-grained 3D view of the coffee cup.

[0071] In one embodiment, the AR system may function as a multi-plane focusing system. In other words, all six LOEs may be illuminated simultaneously so that images appearing to originate from six fixed depth planes are generated in rapid succession with the light source rapidly communicating image information to LOE 1, then LOE 2, then LOE 3, etc. For example, a portion of a desired image, including an image of the sky at optical infinity, may be projected at time 1, and an LOE 190 that maintains light collimation (e.g., depth plane 6 from FIG. 4) may be used. An image of a closer tree branch may then be projected at time 2, and an LOE 190 configured to generate an image that appears to originate from a depth plane 10 meters away (e.g., depth plane 5 from FIG. 4) may be used. An image of a pen may then be projected at time 3, and an LOE 190 configured to generate an image that appears to originate from a depth plane 1 meter away may be used. This type of paradigm can be repeated in a rapid time-sequential manner (eg, 360 Hz) such that the user's eyes and brain (eg, visual cortex) perceive the inputs as being all part of the same image.

[0072] The AR system is required to project images (i.e., by diverging or converging light beams) that appear to originate from various locations along the Z axis (i.e., depth planes) and generate images for a 3D experience. As used herein, light beams include, but are not limited to, directional projections of light energy (including visible and non-visible light energy) emanating from a light source. Generating images that appear to originate from various depth planes accommodates the vergence and accommodation of the user's eyes, minimizing or eliminating vergence-accommodation conflicts for the images.

[0073] Figure 1 depicts a portion of a basic optical system 100 for projecting an image onto a single depth plane. System 100 includes a light source 120 and a LOE 190 having a diffraction optical element (not shown) and an internal coupling grating 192 (ICG) associated therewith. The diffraction optical element may be of any type, including volume or surface relief. In one embodiment, ICG 192 is a reflective-mode aluminum-coated portion of LOE 190. In another embodiment, ICG 192 is a transmissive diffraction portion of LOE 190. When system 100 is in use, a light beam from light source 120 is incident on LOE 190 via ICG 192 and propagates along LOE 190 by means of substantially total internal reflection (“TIR”) for display to the user's eye. Although only one beam is shown in FIG. 1, it should be understood that multiple beams may be incident on LOE 190 from a wide range of angles through the same ICG 192. A light beam “incident on” or “received by” an LOE includes, but is not limited to, a light beam that interacts with the LOE such that it propagates along the LOE by means of substantially TIR. The system 100 depicted in FIG. 1 can include various light sources 120 (e.g., LEDs, OLEDs, lasers, and masked wide-area / broadband emitters). In other embodiments, light from light source 120 may be delivered to LOE 190 via an optical fiber cable (not shown).

[0074] 2 depicts another optical system 100′ that includes a light source 120, three LOEs 190, and three individual internal coupling gratings 192. The optical system 100′ also includes three beam splitters or dichroic mirrors 162 (to direct light to the individual LOEs) and three LC shutters 164 (to control when the LOEs are illuminated). When the system 100′ is in use, the light beam from the light source 120 is split into three sub-beams / beamlets by the three beam splitters 162. The three beam splitters also redirect the beamlets toward the individual internal coupling gratings 192. After the beamlets enter the LOEs 190 through the individual internal coupling gratings 192, they propagate along the LOEs 190 by substantial TIR, where they interact with additional optical structures to produce a display to a user's eye. The surface of the internal coupling grating 192 on the far side of the optical path can be coated with an opaque material (e.g., aluminum) to prevent light from passing through the internal coupling grating 192 to the next LOE 190. In one embodiment, the beamsplitter 162 can be combined with wavelength filters to generate red, green, and blue beamlets. In such an embodiment, three LOEs 190 are required to display a color image in a single depth plane. In another embodiment, the LOEs 190 may each present a portion of a larger single depth plane image area that is angularly displaced laterally within the user's field of view, either of similar or different colors (a "tiled field of view").

[0075] FIG. 3 depicts yet another optical system 100″ having six beam splitters 162, six LC shutters 164, and six LOEs 190, each with its own ICG 192. As explained above during the discussion of FIG. 2, three LOEs 190 are required to display a color image in a single depth plane. Thus, the six LOEs 190 of this system 100″ are capable of displaying color images in two depth planes.

[0076] FIG. 5 depicts the LOE 190 having the ICG 192, the orthogonal pupil expander 194 (“OPE”), and the exit pupil expander 196 (“EPE”).

[0077] As shown in FIGS. 1-4, as the depth plane, the field tile, or the number of colors generated increases (e.g., with an increase in AR scenario quality), the number of LOEs 190 and ICGs 192 also increases. For example, a single RGB color depth plane requires at least three LOEs 190 with three ICGs 192. As a result, the chance of accidental internal coupling of real-world light in these optical elements also increases. Further, all real-world light can be internally coupled along the LOE 190, including an external coupling grating (not shown). Thus, the increase in the number of optical elements required to produce an acceptable AR scenario exacerbates the problem of rainbow artifacts from internally coupled real-world light. (Pupil Expander)

[0078] The LOE 190 discussed above can additionally function as the exit pupil expander 196 (“EPE”) to increase the numerical aperture of the light source 120, thereby increasing the resolution of the system 100. Since the light source 120 generates light with a small diameter / spot size, the EPE 196 expands the apparent size of the pupil of the light exiting the LOE 190, increasing the system resolution. In other embodiments of the AR system 100, the system may further include an orthogonal pupil expander 194 (“OPE”) in addition to the EPE 196 to expand the light in both the X and Y directions. Further details regarding the EPE 196 and the OPE 194 are described in U.S. Patent Application Nos. 14 / 555,585 and 14 / 726,424, the contents of which are already incorporated by reference.

[0079] FIG. 5 depicts the LOE 190 having the ICG 192, the OPE 194, and the EPE 196. FIG. 5 depicts the LOE 190 from a top view that is similar to the view from the user's eye. The ICG 192, the OPE 194, and the EPE 196 may be any type of DOE including a solid or surface relief.

[0080] The ICG 192 is a DOE (e.g., a linear grating) configured to receive light from the light source 120 for propagation by TIR. In the embodiment depicted in FIG. 5, the light source 120 is disposed on the side surface of the LOE 190.

[0081] The OPE 194 is a DOE (e.g., a linear grating) that is tilted in a lateral plane (i.e., perpendicular to the optical path) such that the light beam propagating through the system 100 will be deflected 90 degrees laterally. The OPE 194 is also partially transmissive and partially reflective along the optical path such that the light beam passes partially through the OPE 194 and forms a plurality (e.g., 11) of beamlets. In one embodiment, the optical path is along the X-axis and the OPE 194 is configured to bend the beamlets with respect to the Y-axis.

[0082] The EPE 196 is a DOE (e.g., a linear grating) that is tilted in an axial plane (i.e., parallel to the optical path or the Y-direction) such that the beamlets propagating through the system 100 will be deflected 90 degrees axially. The EPE 196 is also partially transmissive and partially reflective along the optical path (Y-axis) such that the beamlets pass partially through the EPE 196 and form a plurality (e.g., 7) of beamlets. The EPE 196 is also tilted in the Z-direction with respect to the direction portion of the beamlets propagating towards the user's eye.

[0083] Both OPE 194 and EPE 196 are also at least partially transmissive along the Z axis, allowing real-world light (e.g., reflected from real-world objects) to pass through OPE 194 and EPE 196 in the Z direction and reach the user's eyes. In some embodiments, ICG 192 is at least partially transmissive along the Z axis and also at least partially transmissive along the Z axis to accept real-world light. However, when ICG 192, OPE 194, or EPE 196 are transmissive diffractive portions of LOE 190, they may unintentionally incouple real-world light into LOE 190. As explained above, this unintentionally incoupled real-world light may be outcoupled into the user's eyes and form rainbow artifacts. (Rainbow artifact problem)

[0084] FIG. 6 is an end view of a prior art AR system 100 having an LOE 190. The LOE 190 is similar to that depicted in FIG. 5, but only the ICG 192 and EPE 196 are depicted in FIG. 6, and the OPE 194 is omitted for clarity. Several example light beams from various sources are illustrated to demonstrate the rainbow artifact problem mentioned above. A virtual light beam 302 generated by the light source 120 is internally coupled into the LOE 190 by the ICG 192. The virtual light beam 302 carries information about a virtual object 338 (e.g., a virtual robot) generated by the AR system 100.

[0085] Virtual light beam 302 propagates through LOE 190 by TIR and partially exits each time it impinges on EPE 196. In FIG. 6 , virtual light beam 302 impinges at two locations on EPE 196. The exiting virtual light beamlets 302′ are sent to user's eye 304 at angles determined by AR system 100. The virtual light beamlets 302′ depicted in FIG. 6 are approximately parallel to one another. Virtual light beamlets 302′ would therefore render an image (e.g., virtual robot virtual object 338) that appears to originate from near infinity. Virtual light beamlets 302′ can be sent to user's eye 304 at a wide range of angles relative to one another to render an image that appears to originate from a wide range of distances from the user's eye.

[0086] LOE 190 is also transparent to real-world light beams 306, such as those reflected from real-world objects 308 (e.g., distant trees). Because the tree 308 depicted in FIG. 6 is far from the user's eye 304, the real-world light beams 302 are generally parallel to one another. Real-world light beams 306 pass through LOE 190 because LOE 190 is transparent to light. Real-world objects 308 at closer distances to the user's eye 304 will diverge from one another but will still pass substantially through LOE 190.

[0087] The problem is that this prior art LOE190 also internally couples (by refraction) an overhead real-world light beam 312a from above the user (e.g., an overhead light source such as sunlight, ceiling light, street light, etc.) that is sent to the LOE190 in the upper portion of the LOE190. The upper portion of the LOE190 corresponds to, for example, the upper portion on the world side such as the upper portion of the headset when the headset is worn as designed and the user is standing upright or sitting. For example, the overhead real-world light source 314 (e.g., the sun) above the user depicted in FIG. 6 is in an overhead position relative to the LOE190. Although the sun 314 is depicted to the right of the LOE190, the sun 314 can be in a high position in the air above the LOE190 and typically is. Since sunlight from the sun is typically above the user, the sunlight will enter the headset from the upper portion on the world side, while most light beams from physical objects in the user's physical environment will enter the headset more in the field of view portion of the headset, in contrast to the upper portion on the world side of the headset through which the overhead light source enters (assuming the user is looking at a physical object).

[0088] The sun 314 is an overhead real-world light source that can generate a rainbow artifact 316a because it is also bright. Other objects 314 that can generate a rainbow artifact 316a include overhead light sources (e.g., ceiling lights, street lights, etc.) that accidentally collide onto the LOE190 from above the user. The brightness of the overhead real-world light source can cause diffraction within the LOE190 and thus generate a rainbow artifact in the vicinity of the virtual object 338 generated from the light source 302. Diffraction is a process by which light waves are split into dark and bright bands or spectral colors. Light passing through a narrow opening in a blind that covers the floor with bright and dark shadows and patterns is an example of diffraction.

[0089] As shown in FIG. 6 , overhead real-world beam 312a may be internally coupled into LOE 190 at its exterior surface 310. Due to the refractive index of the material from which LOE 190 is fabricated, internally coupled overhead real-world beam 312a′ changes its trajectory from overhead real-world beam 312a. Finally, when internally coupled overhead real-world beam 312a′ impinges on EPE 196, it exits LOE 190 as outgoing overhead real-world beam 312a″ with a further changed trajectory. As shown in FIG. 6 , outgoing overhead real-world beam 312a″ renders a rainbow image / artifact 316a within the field of view near virtual object 338. In FIG. 6 , rainbow image / artifact 316a appears to occur within a location near virtual object 338. The unintended juxtaposition of the rainbow image / artifact 316a next to the virtual object 338 may interfere with the intended effect of the AR scenario.

[0090] Because AR system 100 requires some transparency to real-world light beam 306, its LOE 190 suffers from unintended in-coupling of overhead real-world light beam 312 a and rainbow artifacts created when the in-coupling overhead real-world beam 312 a″ exits LOE 190. While single beams and beamlets are depicted in FIG. 6 for clarity, it should be understood that each single beam or beamlet depicted in FIG. 6 represents multiple beams or beamlets that carry related information and have similar trajectories. While embodiments herein are described with respect to reducing rainbow artifacts, embodiments may also reduce other optical artifacts resulting from the inadvertent in-coupling of external light. (External covering lens for light-guiding optical elements)

[0091] 7 is an end view of a lens disposed adjacent to and external to a light directing optical element of an augmented reality system, according to some embodiments of the present disclosure. LOE 190 includes ICG 192, OPE (not shown), EPE 196, and lens 350. Lens 350 is disposed adjacent to and external to surface 310 of LOE 190. Lens 350 can include tinting and be configured to absorb real-world light via the tinting, such that the amount of real-world light transmitted through the tinted lens and transmitted through the light directing optical element (e.g., LOE 190) is reduced. The tinted lens may also be configured as a gradient tinted lens, where the world-side top portion of the lens absorbs more real-world light (e.g., reduces more light / transmits less light) to minimize "rainbow" artifacts produced from bright overhead light sources, and the world-side bottom portion of the lens absorbs less real-world light (e.g., reduces less light / transmits more light) to allow sufficient light to transmit through the LOE 190. The amount of real-world light transmitted through a gradient lens may be such that 5% of the light transmitted through the lens is T avg = 5%, 33% of the light transmitted through the lens is T avg The transmittance average (T) is expressed as 33%. avg ").

[0092] For example, in Figure 7, the sun 314 is overhead / above the user of the augmented reality system. The real-world overhead light source 314 (e.g., the sun) emits an overhead real-world light beam 312b. As the overhead real-world light beam enters lens 350 at the upper portion of the gradient-tinted lens (e.g., depicted as on the right side of Figure 7), a significant percentage of the overhead real-world light beam 312b is absorbed within the tinting of lens 350, such that a reduced real-world light beam 312b' (shown as a dashed line) is transmitted through lens 350 and through the clear LOE 190. For example, if the upper portion of lens 350 is gradient-tinted with 5% T avg, only 5% of the overhead real-world light beam 312b (eg, reduced real-world light beam 312b') is transmitted through lens 350 and through LOE 190.

[0093] As reduced real-world light beam 312b′ exits LOE 190, it may still be diffracted by elements within LOE 190, such that diffracted light beam 312b″ may enter user's eye 304 and thus create reduced rainbow artifact 316b perceived by the user of the AR system. Note that rainbow artifact 316a in FIG. 6 appears significantly brighter than reduced rainbow artifact 316b in FIG. 7 because, in FIG. 6, overhead real-world light beam 312a enters LOE 190 with its full intensity (e.g., without lens 350 having gradient coloration to absorb some of light 312b as illustrated in FIG. 7, or any coloration to absorb any portion of the overhead light). At full intensity, the diffraction of light beam 312a'' into the eye is much stronger and brighter, thus providing a rainbow artifact 316a that is perceived by the user as a brighter rainbow effect than the reduced rainbow artifact 316b in FIG. 7, which minimizes the rainbow effect compared to FIG. 6. Because reduced real-world light beam 312b' is not as strong as real-world light beam 312a', the intensity and brightness of reduced real-world light beam 312b' produces a rainbow artifact 316b that is less bright and less intense.

[0094] As discussed above, a balance exists between the amount of light that should be allowed through lens 350 to maintain the augmented reality of the displayed virtual content with sufficient lighting in the user's physical environment, and the amount of light that should be blocked by lens 350 to minimize rainbow artifacts.

[0095] Figure 8 is a front view of a gradient-colored lens of an AR system according to some embodiments of the present disclosure. Note that the dashed lines depicted in Figure 8 merely illustrate imaginary lines transverse to the y-axis of the lens having a uniform / fixed coloring degree. Lens 350 has variable coloring where the variation in coloring is a function of the geometry. The coloring degree at any given location is fixed with respect to the y-axis of lens 350. The percentage of transmittance of the coloring (e.g., T avg ) is determined by balancing the user's perception of the opacity of the virtual content (e.g., the opacity improves with less external light transmittance), the reduced rainbow artifacts (e.g., improves with less external light transmittance), and enabling sufficient external light transmittance for the user to clearly see / interact with the real world (improves with more external light transmittance). The transmittance (e.g., T avg ) measured at various points on the EPE is shown in Figure 8 and the specifications are defined at each of the various points. In some embodiments, the "sweet spot" transmittance percentage gradient (e.g., shown in Figure 8) provides content substantially without rainbows at an acceptable opacity while enabling sufficient world light to be seen for the user to interact with the physical objects viewed by the user through the AR system of the real world.

[0096] As discussed above, gradient coloring controls (a) the peripheral light effects of rainbow artifacts and (b) the brightness that cancels or improves the virtual content perception through the lens assembly. Lens 350 has various T avg values with respect to the y-axis of the lens. As shown in Figure 8, in some embodiments, the gradient-colored lens may include the upper edge 810 of the lens where the coloring at the upper edge 810 may have, as an example, 5% T avg . At position 820 with respect to the y-axis of the lens, the coloring has, as an example, 18% T avgThis area of lens 350 that has a gradient tint (e.g., between top edge 810 and location 820) may be referred to in this disclosure as the upper portion of the gradient-tinted lens.

[0097] At position 830 relative to the y-axis of the lens, the tint is, for example, 28% T avg which may have a T avg 8. As shown in FIG. 8, the gradient coloration absorbs less light than that incident at positions 830 and 840, where T avg , and thus the area of lens 350 between location 840 and the bottom edge 850 of the lens may be referred to as the bottom portion of the gradient-tinted lens in this disclosure. avg and different positions (eg, 820, 830, and 840) may be different based on additional optimization studies.

[0098] The gradient is neutral density so that each wavelength of light is absorbed equally, and therefore ambient light transmitted through the window appears neutral to the user in terms of temperature and coloration. That is, the gradient is true gray. In some embodiments, T avg is the 5% T at the top edge 810 of the lens 350 in a linear fashion. avg to 33% T at position 840 avg Those skilled in the art will appreciate that the T avg It can be appreciated that the actual values of are merely example configurations to strike a balance between controlling the ambient light impact of rainbow artifacts and brightness that counteracts virtual content perception.

[0099] Referring back to FIG. 7, in some embodiments, the augmented reality system may also include a selective reflective coating 320 (e.g., a diverter) that may be reflected from an overhead light source so as not to be accidentally internally coupled within the LOE 190. The selective reflective coating can be angularly selective such that the coated optical element is substantially transmissive to real-world light with a low angle of incidence (“AOI”, e.g., about 90 degrees from the surface of the optical element). At the same time, the coating makes the coated optical element highly reflective to oblique real-world light with a high AOI (e.g., substantially parallel to the surface of the optical element, about 170 degrees).

[0100] The combination of both the gradient tinted lens and the selective reflective coating 320 can significantly reduce rainbow artifacts resulting from overhead lighting such as sunlight and / or ceiling lighting, as an example. Since sunlight and / or ceiling lights can impinge on the reflective coating 320 from a relatively high AOI, the light beam 312b can be reflected as illustrated by the reflected light beam 313, thereby further reducing the amount of overhead light from entering the LOE 190. The selective reflective coating 320 is disposed on the outer surface 310 of the LOE 190. The selective reflective coating 320 can be configured to reflect light having various characteristics depending on the state in which the coating 320 is “tuned”. In one embodiment, the coating is adjusted to selectively reflect light impinging on the coating 320 at a relatively high AOI while allowing light impinging on the coating 320 at a relatively low AOI to pass through the coating. The coating 320 is also adjusted to allow relatively low AOI light to pass through it without significantly changing the angle of its trajectory. Further details regarding the coating 320 (e.g., a diverter) are described in U.S. Patent Application No. 15 / 479,700, which is incorporated by reference above.

[0101] Alternatively, or in addition, a reflective coating 320 (e.g., a deflector) such as that depicted in U.S. Patent Application No. 15 / 479,700 may be incorporated into the coating of lens 350 to reflect overhead light, thereby further reducing the amount of overhead light that can be transmitted through lens 350 and through LOE 190.

[0102] Single beams and beamlets are depicted in FIGS. 6 and 7, which it should be understood are for clarity. Each single beam or beamlet depicted in FIGS. 6 and 7 represents a plurality of beams or beamlets that carry related information and have similar trajectories.

[0103] Lens 350, having gradient coloring, may reduce the field of view by reducing real-world overhead light, but reduction or minimization of rainbow artifacts is an advantage that may outweigh the sacrifice of reduced illumination in the user's field of view. Further, the gradient coloring of lens 350 may be adjusted to reduce rainbow artifacts while retaining an acceptable field of view. Indeed, reducing overhead light improves the realism in the content of virtual objects displayed within the field of view, as discussed above.

[0104] The embodiments described herein include gradient tinted lenses, and one skilled in the art can understand that the gradient tinted lenses may include a lens 350 having a gradient tinting coating applied to the surface of the lens 350. In some embodiments, an optical coating may be applied to the surface of the lens, and the optical coating may include a gradient tinting coating, an anti-reflection coating, a hard coating, a mirror coating, a dirt-repellent coating, and / or an alignment marking. The alignment marking provides a marker for aligning the gradient during assembly. In some embodiments, the gradient tinted lens is elliptical and not circular. One skilled in the art can understand that the shape of the gradient tinted lens may be a different shape other than elliptical or circular, and the shape of the lens may be according to the use case for solving a certain problem. The alignment marking is further disclosed below.

[0105] In some embodiments, the gradient of the tint may be a gradient film attached to the protective lens. In some embodiments, the gradient of the tint may be manufactured directly into the lens itself. In some embodiments, the gradient of the tint may be coated on the surface 310 of the LOE 190 such that the outer lens can be used as a protective structure instead of an absorptive structure.

[0106] In some embodiments, blocking external overhead light transmission may be accomplished by a combination of absorption of some external light (gradient tinting) and reflection of some external light (e.g., a diverting element such as a reflective and / or mirror coating).

[0107] In some embodiments, the lens material may be, by way of example, Trivex material, which may be approximately 1 mm thick, (a) weatherproof, (b) impart minimal (ideally zero) distortion / optical power to external light transmitted through the exterior window, and (c) have a refractive index of 1.58, approximately the same as the waveguide glass refractive index. In other embodiments, the lens material may be, by way of example, polycarbonate. In still other embodiments, the lens material may be, by way of example, plastic and / or glass.

[0108] In some embodiments, lens 350 is geographically modulated relative to the eyebox instead of EPE 196. An eyebox may be a box that provides a means of seeing or observing in a particular way. An eyebox may be a volume of space within which a virtually visible image is formed by a lens system or visual display (e.g., an augmented reality system) and represents a combination of exit pupil size and pupil distance.

[0109] 9 illustrates multiple views of a flat peripheral surface around the edge of a lens 350 of an augmented reality system, according to some embodiments of the present disclosure. The lens 350 may include an outwardly facing surface 910, an inwardly facing surface 920, a first flat peripheral surface 930 having a flat surface width 950, and a second flat peripheral surface 940 having a flat surface height 960. The first flat peripheral surface 930 and the second flat peripheral surface 940, which are configured around the edge of the gradient lens and enable interfacing and / or sealing with a mounting portion, an eyeglass frame, and / or an AR headset, may all be referred to hereinafter as a "mounting portion."

[0110] Conventional lens designs generally include a curved or rounded peripheral surface of the lens, facilitating simple snap fit / snap fit release configuration and assembly of the lens into its respective mounting portion. However, the present disclosure includes flat peripheral surfaces 930 and 940 around the edge of the lens 350, facilitating interfacial contact and / or sealing with the mounting portion. For example, in some embodiments, the lens 350 may rely on the flat peripheral surface of the lens because it is a protective cover lens that is disposed outside the surface of the light guiding optical element adjacent to the light guiding optical element and protects the light guiding optical element from physical contact with external objects in the user's physical environment. Having a rounded edge lens that can protrude from the mounting portion in response to contact with an external object in the user's physical environment may not serve its purpose of protecting the light guiding optical element. Thus, in some embodiments, the lens 350 may include a flat peripheral surface and enable interfacial contact / sealing with the mounting portion.

[0111] Measurements of the flat surface width 950 and the flat surface height 960 may depend on the flat surface area of the mounting portion for attachment. In some embodiments, the flat surface area of the mounting portion may depend on the flat surface width 950 and the flat surface height 960 because the measurements of the flat peripheral surfaces (e.g., 950 and 960) may depend on the thickness of the lens 350, the curvature of the lens 350, or a combination thereof.

[0112] In some embodiments, the shape of the lens 350 may include a flat portion around the edge where an adhesive is applied during the assembly of a window (e.g., the lens 350) external to the magnesium mounting portion / frame. Sunglass lenses generally include a chamfered bevel that allows the lens to snap fit into the mounting portion / frame, and the mounting portion / frame may have some flexibility. However, in some embodiments including a magnesium mounting portion / frame, such flexibility is not available. Thus, the lens must be glued onto it.

[0113] In some embodiments, the lens 350 may include at least one or more coatings such as gradient tinting coating, hard coating, mirror coating, anti-fouling coating, and / or anti-reflection. The lens 350 may have a center thickness of 1.20+ / -0.2 mm. The lens 350 may have a radius of curvature of 86.8+ / -0.9 mm.

[0114] Figure 10 is a front view of the lens 350 of an extended reality system according to some embodiments of the present disclosure. The external lens / window (e.g., the lens 350) may not be uniform in size and shape (e.g., elliptical, circular, square, etc.). The lens 350 has gradient tinting and is not a perfect circle. Alignment / orientation markers 1010 may be used to ensure that the lens is correctly oriented within its mounting during assembly. The orientation markers may be placed at the east, north, and west locations with respect to the lens 350 as depicted in FIG. 10. In conventional embodiments, the ink used for the alignment marker 1010 is wiped off so that the orientation marks are not visible to the user after the assembly of the lens to its mounting is complete. Since the alignment / orientation markers 1010 are removed, the external window (e.g., the lens 350) cannot be reattached to its mounting once the alignment / orientation markers 1010 are removed from the mounting, for example, for maintenance of the AR system.

[0115] In some embodiments, a special type of ink may be used as the alignment / orientation marker 1010. The special type of ink may be visible under certain types of light within a factory or repair facility. However, the special type of ink will be invisible to the user during normal use of the AR system. The special type of ink may then be left on the outer lens after the initial assembly of the lens onto the eyeglass frame so that after maintenance work is completed on the lens or eyeglass frame, the lens can be reused and reassembled. In some embodiments, the special type of ink may be an infrared (IR) ink or an ultraviolet (UV) fluorescent ink. In some embodiments, the marking material and / or the marking process may be developed by Essilor®, by way of example. (Controllable External Coating Lens System)

[0116] FIG. 11 depicts a controllable dimming assembly that can form all or part of an external coating lens of a system (e.g., an augmented reality system) according to some embodiments of the present disclosure. More specifically, FIG. 11 depicts a controllable dimming assembly that includes a liquid crystal layer 1108 sandwiched between an outer electrode 1106A and an inner electrode 1106B, and thus between an outer polarizer 1102A and an inner polarizer 1102B. In some examples, the controllable dimming assembly may further include an outer compensation film layer 1104A (or wave plate) positioned between the outer polarizer 1102A and the outer electrode 1106A, an inner compensation film layer 1104B (or wave plate) positioned between the inner polarizer 1102B and the inner electrode 1106B, or both.

[0117] In operation, the outer polarizer 1102A may impart a first polarization state (e.g., vertical polarization) to ambient light propagating therethrough toward the user's eyes. Liquid crystal molecules contained within the liquid crystal layer 1108 may then further rotate / polarize the polarized ambient light in accordance with one or more electric fields applied across the outer and inner electrodes 1106A, 1106B. It follows that the polarization rotation imparted by the pair of electrodes 1106A, 1106B and the liquid crystal layer 1108 may effectively modify the polarization state of the ambient light passing therethrough. In some embodiments, retardation and / or additional polarization rotation may be imparted using the outer and / or inner compensation film layers 1104A, 1104B. Finally, the inner polarizer 1102B may impart a second, different polarization state (e.g., horizontal polarization) to ambient light propagating therethrough toward the user's eyes. The second polarization state may be configured to be approximately orthogonal to the cumulative polarization state imparted on the ambient light by the combined effect of the outer polarizer 1102A, the liquid crystal layer 1108, and optionally the outer and / or inner compensation film layers 1104A, 1104B. Thus, the inner polarizer 1102B may allow the portion of the ambient light in the second polarization state that passes therethrough to be unaffected and may attenuate the portion of the ambient light in a polarization state other than the second polarization state.

[0118] In some implementations, the controllable dimming assembly of FIG. 11 may be configured to generate a gradient or otherwise non-uniform coloring / dimming pattern and attenuate ambient light incident thereon in a manner similar to that of lens 350 (see FIG. 7). The controllable dimming assembly of FIG. 11 may be configured to generate a gradient in response to the application of one or more electric fields / voltages across outer and inner electrodes 1106A, 1106B. Examples of such patterns are shown in FIGS. 12A-12D. Additionally, the system to which the controllable dimming assembly of FIG. 11 belongs may provide for the temporal adjustment of the global level of opacity of such spatially varying dimming patterns based on any of a variety of different factors. In some embodiments, the controllable dimming assembly is configured to impart a polarization state that varies based on the location and / or angle at which ambient light is incident on the component, at least one of its components (e.g., outer polarizer 1102A, inner polarizer 1102B, outer compensating film layer 1104A, inner compensating film layer 1104B, outer electrode 1106A, inner electrode 1106B, a network of circuitry electrically coupled to outer electrode 1106A and / or inner electrode 1106B, liquid crystal layer 1108, substrate material disposed adjacent to outer electrode 1106A, and / or inner electrode 1106B, etc.) is used to attenuate ambient light passing therethrough according to the gradient coloring / dimming pattern.

[0119] As will be described in further detail below, one or both of outer and inner polarizers 1102A, 1102B may be configured to polarize ambient light passing therethrough in a spatially varying or otherwise non-uniform manner. For example, outer polarizer 1102A may be configured to impart a particular polarization state to ambient light incident on one of its portions / divisions, while imparting a different polarization state to ambient light incident on other portions / divisions.

[0120] In addition, in some implementations, the controllable dimming assembly includes at least one compensating film layer (e.g., one or both of the outer and inner compensating film layers 1104A, 1104B). In some such implementations, such compensating film layers 1104A, 1104B are configured to polarize / rotate / delay ambient light passing therethrough in a manner that varies based on the location and / or angle at which the ambient light impinges on the compensating film layers 1104A, 1104B. In some implementations, the compensating film layers 1104A, 1104B are configured to interact with the light impinging thereon in a manner similar to that of the coating 320, as described above with reference to FIG. 7 and described in further detail in U.S. Patent Application No. 15 / 479,700, which is hereby incorporated by reference in its entirety. For example, the outer compensating film layer 1104A may be configured to polarize / rotate / delay ambient light impinging on one portion / section thereof by a certain amount, while polarizing / rotating / delaying ambient light impinging on other portions / sections thereof by other different amounts. In another example, the outer compensating film layer 1104A may be configured to polarize / rotate / delay ambient light impinging on its surface at a particular angle by a certain amount, while polarizing / rotating / delaying ambient light impinging on its surface at other angles by other different amounts.

[0121] Furthermore, in some embodiments, one or more of the outer and inner electrodes 1106A, 1106B may be configured to produce a spatially varying or otherwise non-uniform electric field therebetween, which in turn may create non-uniformity in the liquid crystal phase within the liquid crystal layer 1108 such that the liquid crystal layer 1108 polarizes / rotates / delays ambient light passing therethrough in the spatially varying or otherwise non-uniform manner. For example, the outer electrode 1106A may be configured to produce a relatively strong electric field at one end thereof, but a relatively weak electric field at another different end thereof. The one end and the different end may be opposing ends along a certain direction on the outer electrode 1106A. This direction may correspond from the bottom to the top of the liquid crystal layer 1108. In various embodiments, the liquid crystal layer 1108 may employ liquid crystal technologies such as dye-doped or guest-host liquid crystals, twisted nematic (TN) or vertical alignment (VA) liquid crystals, or ferroelectric liquid crystals. In some implementations, the liquid crystal layer 1108 may employ an electrically controlled birefringence (ECB) technology such as an ECB cell.

[0122] Similar to the external cover lenses described above with reference to FIGS. 8-10, in some implementations, the geometry of the controllable dimming assembly of FIG. 11 may feature one or more rounded or curved edges and / or surfaces. In some embodiments, the geometry of the controllable dimming assembly of FIG. 11 may be shaped to follow the contours of the frame to which the controllable dimming assembly is physically coupled. In some of these embodiments, the frame may be configured to be centered on the user's head. Thus, in some embodiments, a pair of controllable dimming assemblies may be physically coupled to the frame such that, when the frame is worn by a user, the two controllable dimming assemblies are positioned in front of / aligned with the user's eyes, respectively, in a manner similar to that of a pair of eyepieces. In other embodiments, a single, relatively wide controllable dimming assembly may be physically coupled to the frame such that, when the frame is worn by a user, the controllable dimming assembly is positioned in front of the user's eyes, in a manner similar to that of a visor, face mask, or shield.

[0123] 12A-12D show example dimming patterns according to some embodiments of the present disclosure. FIG. 12A shows a radial gradient dimming pattern G1 whose opacity / transparency varies as a function of Euclidean distance from a corresponding point P1. More specifically, the radial gradient dimming pattern G1 exhibits little / no opacity at point P1 and exhibits increasing amounts of opacity as the Euclidean distance from point P1 increases. Point P1, as depicted in FIG. 12A, may represent a point in the radial gradient dimming pattern G1 that exhibits a global minimum level of opacity. It follows that the point in the radial gradient dimming pattern G1 located farthest from point P1 may represent a point in the dimming pattern G1 that exhibits a global maximum level of opacity. FIG. 12B shows a radial gradient dimming pattern G2 whose opacity / transparency varies as a function of Euclidean distance from a corresponding point P2. As shown in Figure 12B, radial gradient dimming pattern G2 exhibits a high level of opacity at point P2 and a decreasing amount of opacity as the Euclidean distance from point P2 increases. Point P2 may represent the point in radial gradient dimming pattern G2 that exhibits a global maximum level of opacity, as depicted in Figure 12B, while the point in radial gradient dimming pattern G2 located furthest from point P2 may represent the point in dimming pattern G2 that exhibits a global minimum level of opacity. Figure 12C shows linear gradient dimming pattern G3, in which opacity / transparency varies linearly from one end to another in a manner similar to the gradient coloring pattern of lens 350. Similar to dimming patterns G1 and G2, a set of one or more points at one end of linear gradient dimming pattern G3 may represent points within dimming pattern G3 that exhibit a global minimum level of opacity, while a set of one or more points at another end of linear gradient dimming pattern G3 may represent points within dimming pattern G3 that exhibit a global maximum level of opacity. Figure 12D shows a radial gradient dimming pattern G4 whose opacity / transparency varies as a function of Euclidean distance from its center. As shown in Figure 12D, radial gradient dimming pattern G4 exhibits little / no opacity at its center and exhibits increasing amounts of opacity as the Euclidean distance from the center increases.Similar to dimming patterns G1-G3, a set of one or more points at the center of radial gradient dimming pattern G4 may represent points within dimming pattern G4 at which a global minimum level of opacity is exhibited, while multiple points positioned along the periphery of dimming pattern G4 may represent points within dimming pattern G4 at which a global maximum level of opacity is exhibited.

[0124] In some implementations, the change in opacity as a function of position for a set of one or more points within a given dimming pattern that exhibit a global minimum or maximum opacity level may be linear, exponential, logarithmic, or otherwise polynomial in nature. Furthermore, in some examples, the gradient vectors associated with a given dimming pattern may all have the same magnitude and direction. In some embodiments, such as those employing a radial gradient dimming pattern, the gradient vectors associated with a given dimming pattern may not all have the same direction. In some implementations, a system, such as the controllable dimming assembly of FIG. 11 , may adjust the global level of opacity of a dimming pattern over time by making adjustments to one or both of the global minimum and maximum opacity levels. As noted above, in some examples, adjustments to the global opacity level may be made based on any of a variety of different factors, some of which are described in further detail below.

[0125] 13A-13D illustrate exemplary polarizers configured to create dimming patterns according to some embodiments of the present disclosure. In some implementations, one or more of the exemplary polarizers in FIGS. 13A-13D may be implemented within a controllable dimming assembly in a manner similar to that of the outer and / or inner polarizers 1102A, 1102B as described above with reference to FIG. 11. In some examples, the exemplary polarizers illustrated in FIGS. 13A-13D may each include one or more linear wire-grid polarizer components. Alternatively, or in addition, in some implementations, the exemplary polarizers illustrated in FIGS. 13A-13D may each include multiple thin-film micropolarizer components. Furthermore, the exemplary polarizers illustrated in FIGS. 13A-13D may each include multiple distinct polarizer regions / segments R1-R4, each configured to impart a different polarization state to ambient light propagating therethrough. For example, ambient light propagating through the distinct polarizer region / section R1 of a given exemplary polarizer of a controllable dimming system may subsequently experience little or no attenuation, while ambient light propagating through the distinct polarizer region / section R4 of such exemplary polarizer may subsequently experience a relatively large amount of attenuation (e.g., 10 degrees or 45 degrees). In this example, ambient light passing through the distinct polarizer region / section R2 may be attenuated to an extent greater than that passing through the distinct polarizer region / section R1 and less than that passing through the distinct polarizer region / section R4. In this example, ambient light passing through the distinct polarizer region / section R3 may be attenuated to an extent greater than that passing through the distinct polarizer region / section R2 and less than that passing through the distinct polarizer region / section R4.

[0126] FIG. 13A illustrates an exemplary polarizer 1102-G1 of a controllable dimming system configured to polarize ambient light passing therethrough such that a controllable dimming assembly attenuates the ambient light according to the radial gradient dimming pattern G1 of FIG. 12A. FIG. 13B illustrates an exemplary polarizer 1102-G2 of a controllable dimming system configured to polarize ambient light passing therethrough such that a controllable dimming assembly attenuates the ambient light according to the radial gradient dimming pattern G2 of FIG. 12B. FIG. 13C illustrates an exemplary polarizer 1102-G3 of a controllable dimming system configured to polarize ambient light passing therethrough such that a controllable dimming assembly attenuates the ambient light according to the linear gradient dimming pattern G3 of FIG. 12C. FIG. 13D illustrates an exemplary polarizer 1102-G4 of a controllable dimming system configured to polarize ambient light passing therethrough such that a controllable dimming assembly attenuates the ambient light according to the radial gradient dimming pattern G4 of FIG. 12D.

[0127] As described above, in some embodiments, the controllable dimming assembly is configured to interact with ambient light passing therethrough in a manner that varies based on the angle at which the ambient light impinges thereon, and may include at least one compensating film layer (e.g., one or both of the outer and inner compensating film layers 1104A, 1104B). Examples of components that may serve as or be included as part of the at least one compensating film layer include one or more coatings such as coating 320 described above, and / or a uniaxial retardation film (e.g., a polycarbonate resin film such as PureAce®), a biaxial retardation film (e.g., a triacetyl cellulose (“TAC”) film, a cycloolefin polymer (“COP”) film, etc.), and a liquid crystal film (e.g., a wide viewing (“WV”) film, a twisted nematic film, a hybrid nematic film, a vertical alignment film, etc.), and equivalents, and may be configured to interact with light impinging thereon in a manner similar to that of coating 320 described above. In implementations where the at least one compensating film includes one or more retardation films or other optical compensating films, such films may be adjusted or otherwise processed using any of a variety of techniques (e.g., a directional “stretching” and / or “rubbing” process, etc.) such that the controllable dimming system is configured to attenuate a relatively large amount of oblique ambient light with a high AOI and a relatively small amount of ambient light with a lower AOI. Additional examples of materials, configurations, techniques, and operating principles that may be utilized in implementing the at least one compensating film layer described above are provided in U.S. Patent Application No. 15 / 479,700, which is hereby incorporated herein by reference in its entirety.

[0128] As mentioned above, in some embodiments, the controllable dimming assembly may include at least one compensation film layer (e.g., one or both of the outer and inner compensation film layers 1104A, 1104B) configured to interact with ambient light passing therethrough in a manner that varies based on where the ambient light impinges thereon. Examples of components that may serve as or be included as part of the at least one compensation film layer in such embodiments may include retarders and wave plates that are spatially varied or otherwise patterned in a manner similar to one or more of the exemplary polarizers described herein with reference to FIGS. 13A-13D. In other words, such components may comprise distinct sections / regions that are configured to retard or rotate light passing therethrough in different manners. For example, such a component may be configured to retard or rotate ambient light incident on an upper portion / segment thereof by a particular amount (similar to segment / region R4 in FIGS. 13A-13D ), but polarize / rotate / retard ambient light incident on other, lower portions / segments thereof by other, lesser amounts (similar to one or more of segments / regions R1, R2, and R3 in FIGS. 13A-13D ). In some implementations, such a component may include one or more liquid crystal layers that are tuned or otherwise processed using any of a variety of techniques, such as one or more of those described in U.S. Patent Application No. 15 / 815,449 and / or U.S. Patent Application No. 15 / 795,067 (both of which are incorporated herein by reference in their entireties).

[0129] 14A-14C illustrate exemplary electrode assemblies configured to create a dimming pattern according to some embodiments of the present disclosure. In some implementations, one or more of the exemplary electrode assemblies in FIGS. 14A-14C may be implemented within a controllable dimming assembly in a manner similar to that of the outer and / or inner electrodes 1106A, 1106B as described above with reference to FIG. 11. More specifically, FIGS. 14A-14C each illustrate exemplary electrode assemblies including at least one electrode component 1106 embedded in and / or disposed on a substrate material 1107. In some examples, the at least one electrode component 1106 illustrated in one or more of the exemplary electrode assemblies in FIGS. 14A-14C may be a transparent conductive film such as an indium tin oxide (“ITO”) film. Each exemplary electrode assembly may be implemented within a controllable dimming assembly in a manner similar to that of the inner or outer electrodes 1106A, 1106B as described above with reference to FIG. 11. Thus, while each exemplary electrode assembly may be positioned parallel to another electrode assembly, the electrode components 1106 are not necessarily parallel to another electrode assembly. In some embodiments, such another electrode assembly may include a single planar layer of ITO or other transparent conductive film. A layer of liquid crystal molecules, similar to the liquid crystal layer 1108 described above with reference to FIG. 11, may be disposed between each pair of electrode assemblies.

[0130] Figure 14A illustrates an exemplary electrode assembly that includes an inclined planar electrode component 1106. The exemplary electrode assembly of Figure 14A may be implemented, for example, within a controllable dimming assembly in parallel with another electrode assembly and may include a single planar layer of ITO. That is, the surface of the substrate material 1107 may be positioned parallel to the surface of the single planar layer of ITO within the other electrode assembly. Thus, the surface of the electrode component 1106 of the exemplary electrode assembly of Figure 14A may be inclined or otherwise non-parallel with respect to the surface of the single planar layer of ITO within the other electrode assembly, while the exemplary electrode assembly and the other electrode assembly may be stacked in parallel (e.g., on opposite sides of a liquid crystal layer). Accordingly, the distance between the surface of the electrode component 1106 of the exemplary electrode assembly of Figure 14A and the surface of the single planar layer of ITO within the other electrode assembly may be non-uniform. Thus, during operation, a non-uniform electric field may be produced between the exemplary electrode assembly of Figure 14A and the other electrode assembly. The non-uniform electric field may result in non-uniform polarization by the liquid crystal layer, which may in turn result in non-uniform or stepwise attenuation of the light passing through it. The distance between the surface of the electrode component 1106 of the electrode assembly in Figure 14A and the other electrode assembly increases from the bottom to the top of the electrode assembly, so both the electric field and the resulting polarization are stronger at the top of the electrode assembly compared to the bottom, and the light attenuation is greater at the top of the liquid crystal layer.

[0131] Figure 14B illustrates an exemplary electrode assembly comprising a plurality of planar electrode components / segments 1106 positioned at different distances from its planar surface. The exemplary electrode assembly of Figure 14B may be implemented, for example, within a controllable dimming assembly parallel to another electrode assembly and may include a single planar layer of ITO. Similar to the exemplary electrode assembly of Figure 14A, the surface of the substrate material 1107 within the exemplary electrode assembly of Figure 14B may be positioned parallel to the surface of the single planar layer of ITO within another electrode assembly. Due to the relative positions of the planar electrode components / segments 1106 with respect to each other, the distance between the surface of each planar electrode component / segment 1106 within the electrode assembly of Figure 14B and the surface of the single planar layer of ITO within another electrode assembly varies. That is, the distance increases from the bottom to the top of the electrode assembly. Thus, during operation, a non-uniform (i.e., increasing from the bottom to the top) electric field can be produced between the exemplary electrode assembly of Figure 14B and another electrode assembly. As explained above, the increasing electric field results in greater light attenuation at the top of the liquid crystal layer compared to the bottom.

[0132] FIG. 14C illustrates an exemplary electrode assembly comprising an electrode component 1106 with (1) a surface that tilts away from the surface of the substrate material 1107 or is otherwise non-parallel thereto, and (2) a thickness that decreases from the bottom to the top of the electrode assembly. The exemplary electrode assembly of FIG. 14C may be implemented, for example, within a controllable dimming assembly parallel to another electrode assembly and may include a single planar layer of ITO. Similar to the exemplary electrode assemblies of FIGS. 14A and 14B, the surface of the substrate material 1107 within the exemplary electrode assembly of FIG. 14C may be positioned parallel to the surface of the single planar layer of ITO within another electrode assembly. The distance between one surface of the electrode component 1106 within the electrode assembly of FIG. 14C and the surface of the single planar layer of ITO within another electrode assembly varies. That is, the distance increases from the bottom to the top of the electrode assembly. Additionally, the thickness of the electrode component 1106 decreases from the bottom to the top of the electrode assembly. Since the resistance of a given electrical conductor is inversely proportional to the cross-sectional area of the conductor, the resistance of the electrode component 1106 can vary from the bottom to the top of the electrode assembly in response to variations in the thickness of the electrode component 1106. Such a characteristic of the electrode component 1106 depicted in FIG. 14C produces a non-uniform (i.e., increasing from the bottom to the top) electric field between the exemplary electrode assembly of FIG. 14C and other electrode assemblies during operation. As explained above, the increasing electric field results in greater light attenuation at the top of the liquid crystal layer compared to the bottom.

[0133] FIG. 15 illustrates an exemplary electrode assembly comprising a first electrode 1106A of a non-uniform multi-segmented plane and a second electrode 1106B of a uniform plane, according to some embodiments of the present disclosure. In some implementations, the exemplary electrode assembly of FIG. 15 may be implemented within a controllable dimming assembly in a manner similar to that of the outer and inner electrodes 1106A, 1106B as described above with reference to FIG. 11. The second electrode 1106B of the uniform plane may include a single planar layer of ITO. The first and second electrodes 1106A, 1106B may be parallel to each other and disposed on opposite sides of the liquid crystal layer. The first electrode 1106A may include three segments / portions 1116, 1117, 1118 disposed adjacent to each other on the surface of the first electrode 1106A. The first segment 1116 is disposed on top of the first electrode 1106A, the third segment 1118 is disposed at the bottom of the first electrode 1106A, and the second segment 1117 is disposed between the first and third segments 1116, 1118. The first and third segments 1116, 1118 may be formed from a relatively conductive transparent material such as a layer of ITO or other transparent conductive oxide (“TCO”), and the intervening second segment 1117 may be formed from a relatively less conductive transparent material such as a layer including graphene, graphene oxide, and / or carbon nanotube (“CNT”). The exemplary electrode assembly also includes a first voltage source 1126 electrically coupled to the first segment 1116 and a ground electrode electrically coupled to the second electrode 1106B. The exemplary electrode assembly also includes an optional second voltage source 1128 electrically coupled to the third segment 1118.

[0134] In operation, when first and second voltages are applied to the first electrode 1106A (via the first and second voltage sources 1126, 1128), a non-uniform electric field is generated between the first and second electrodes 1106A, 1106B. In particular, when a stronger voltage is applied by the first voltage source 1126 and a weaker voltage is applied by the second voltage source 1128, a non-uniform electric field is generated that approximately increases from the bottom to the top of the first electrode 1106A. In embodiments without the second voltage source 1128, applying a voltage to the first voltage source may generate a similar non-uniform electric field. A non-uniform electric field may result in non-uniform polarization by the liquid crystal layer, which in turn may result in non-uniform or gradual attenuation of light passing therethrough. Because the non-uniform electric field increases approximately from the bottom to the top of the first electrode 1106A, both the electric field and the resulting polarization are stronger at the top of the electrode assembly compared to the bottom, and light attenuation is greater at the top of the liquid crystal layer. In some embodiments, one or more of the example electrode assemblies described herein with reference to Figures 15 and 16A-16D may include only segments 1116 and 1117, and not segment 1118. In these embodiments, segment 1117 may be electrically coupled directly to corresponding circuitry.

[0135] FIG. 16A illustrates an exemplary first electrode 1106-G1 of a controllable dimming system configured to polarize ambient light passing therethrough such that the controllable dimming assembly attenuates the ambient light according to the radial gradient dimming pattern G1 of FIG. 12A. The exemplary first electrode 1106-G1 has three sections / portions 1116, 1117, 1118 that are arranged and shaped similar to the first electrode 1106A depicted in FIG. 15. FIG. 16B illustrates an exemplary first electrode 1106-G2 of a controllable dimming system configured to polarize ambient light passing therethrough such that the controllable dimming assembly attenuates the ambient light according to the radial gradient dimming pattern G2 of FIG. 12B. The exemplary first electrode 1106-G2 has three sections / portions 1116, 1117, 1118 like the first electrode 1106A depicted in FIG. 15, however, the three sections / portions 1116, 1117, 1118 are shaped differently from the corresponding sections within the first electrode 1106A depicted in FIG. 15. FIG. 16C illustrates an exemplary first electrode 1106-G3 of a controllable dimming system configured to polarize ambient light passing therethrough such that the controllable dimming assembly attenuates the ambient light according to the linear gradient dimming pattern G3 of FIG. 12C. The exemplary first electrode 1106-G3 has three sections / portions 1116, 1117, 1118 like the first electrode 1106A depicted in FIG. 15, however, the three sections / portions 1116, 1117, 1118 are shaped differently from the corresponding sections within the first electrode 1106A depicted in FIG. 15. FIG. 16D illustrates an exemplary first electrode 1106-G4 of a controllable dimming system configured to polarize ambient light passing therethrough such that the controllable dimming assembly attenuates the ambient light according to the radial gradient dimming pattern G4 of FIG. 12D. The exemplary first electrode 1106-G3 has three sections / portions 1116, 1117, 1118 like the first electrode 1106A depicted in FIG. 15, however, the three sections / portions 1116, 1117, 1118 are shaped and arranged differently from the corresponding sections within the first electrode 1106A depicted in FIG. 15.

[0136] FIG. 17A illustrates an exemplary electrode assembly comprising first and second electrodes 1106A, 1106B of a non-uniform multi-segmented plane, according to some embodiments of the present disclosure. In some implementations, the exemplary electrode assembly of FIG. 17 may be implemented within a controllable dimming assembly in a manner similar to that of the outer and inner electrodes 1106A, 1106B as described above with reference to FIG. 11. The first and second electrodes 1106A, 1106B may be parallel to each other and disposed on opposite sides of the liquid crystal layer. The first electrode 1106A may include four segments / portions S1, S2, S3, S4 that are disposed adjacent to each other on the surface of the first electrode 1106A but electrically insulated from each other. Insulators may be disposed between segments S1 and S2, S2 and S3, and S3 and S4 to insulate segments S1, S2, S3, S4 from each other. The first segment S1 is disposed on top of the first electrode 1106A, the second segment S2 is disposed further below the first electrode 1106A, the third segment S3 is disposed even further below the first electrode 1106A, and the fourth segment S4 is disposed at the bottom of the first electrode 1106A. Segments S1, S2, S3, S4 may be formed from a relatively conductive transparent material such as a layer of ITO. The second electrode 1106B may include four segments / portions S1’, S2’, S3’, S4’ that are disposed adjacent to each other on the surface of the second electrode 1106B. The first segment S1’ is disposed on top of the second electrode 1106B, the second segment S2’ is disposed further below the second electrode 1106B, the third segment S3’ is disposed even further below the second electrode 1106B, and the fourth segment S4’ is disposed at the bottom of the second electrode 1106B. Segments S1’, S2’, S3’, S4’ may be formed from a relatively conductive transparent material such as a layer of ITO. In some implementations, the exemplary electrode assembly of FIG. 17A may be driven, at least in part, by a voltage divider network such as a circuit or equivalent circuit network described below with reference to FIG. 17B. For example, segments S1, S2, S3, and S4 may be electrically coupled to the circuit described below with reference to FIG. 17B at points A, B, C, and D, respectively.Similarly, in such an embodiment, segments S1’, S2’, S3’, and S4’ may be electrically coupled to the circuit of FIG. 17B at points B, C, D, and E, respectively. During operation, the segments of the first electrode 1106A and the segments of the second electrode 1106B may function as anodes and cathodes, respectively, by virtue of their electrical connection to the circuit network of FIG. 17B. FIG. 17B is a circuit diagram for the exemplary electrode assembly illustrated in FIG. 17A. In particular, FIG. 17B depicts an exemplary voltage divider circuit network for driving each of the electrode segments within the exemplary electrode assembly described above with reference to FIG. 17A. It should be understood that other electrical and / or computational circuits and components may be implemented instead of or in conjunction with the circuit network of FIG. 17B. As shown in FIG. 17B, such a voltage divider circuit network may include at least a voltage source that is electrically coupled in series to a plurality of resistors. In some implementations, the voltage source may be variable, switchable, or otherwise controllable by one or more hardware components electrically coupled thereto, such as a processor, a power supply, a logic gate, and the like. Each anode-cathode pair present within the exemplary electrode assembly illustrated in FIG. 17A may be electrically coupled in parallel with a different one or different combinations of a plurality of resistors. In the embodiments of FIGS. 17A and 17B, the S1-S1’ electrode pair is electrically coupled in parallel with the first resistor R1, the S2-S2’ electrode pair is electrically coupled in parallel with the second resistor R2, the S3-S3’ electrode pair is electrically coupled in parallel with the third resistor R3, and the S4-S4’ electrode pair is electrically coupled in parallel with the fourth resistor R4. Further, in the present embodiment, the resistance of the fourth resistor R4 is greater than the resistance of the third resistor R3, which is greater than the resistance of the second resistor R2, which is greater than the resistance of the first resistor R4. In some embodiments, one or more of the plurality of resistors (e.g., R1, R2, R3, R4) may be disposed along the edge of one of the electrodes (e.g., the first electrode 1106A) within the electrode assembly.In other embodiments, one or more of the plurality of resistors (e.g., R1, R2, R3, R4) may be disposed on the surface of one of the electrodes (e.g., the first electrode 1106A) within the electrode assembly between its respective segments (e.g., S1, S2, S3, S4).

[0137] During operation, when a voltage is applied to the first and second electrodes 1106A, 1106B, a non-uniform electric field is generated between the first and second electrodes 1106A, 1106B. In particular, when the voltage is applied by a voltage source to the first section A of the first electrode 1106A, the voltage is reduced using resistors R1, R2, R3, R4 that are sequentially coupled such that a substantially lower voltage is applied to each subsequent section S2, S3, S4 of the first electrode 1106A. As a result, a non-uniform electric field that approximately increases from the bottom to the top of the first electrode 1106A is generated. The non-uniform electric field can cause non-uniform polarization by the liquid crystal layer, which can in turn cause non-uniform or stepwise attenuation of the light passing through it. Since the non-uniform electric field approximately increases from the bottom to the top of the first electrode 1106A, both the electric field and the resulting polarization are stronger at the top of the electrode assembly compared to the bottom, and the light attenuation is greater at the top of the liquid crystal layer. In some implementations, sections S1’, S2’, and S3’ may not be electrically coupled to the circuit network of FIG. 17B at points B, C, and D respectively, and instead may all be electrically coupled to the circuit network of FIG. 17B at point E in the same manner as section S4’. Thus, all sections of the second electrode 1106B may be electrically coupled to a common ground such that each anode-cathode pair present within the exemplary electrode assembly illustrated in FIG. 17A can be electrically coupled in parallel with different combinations of a plurality of resistors. For example, referring again to the embodiments of FIGS. 17A and 17B, in these implementations, the S1-S1’ electrode pair is electrically coupled in parallel with resistors R1-R4, the S2-S2’ electrode pair is electrically coupled in parallel with resistors R2-R4, the S3-S3’ electrode pair is electrically coupled in parallel with resistors R3-R4, and the S4-S4’ electrode pair is electrically coupled in parallel with the fourth resistor R4. In such implementations, the quantitative relationship between the values of the plurality of resistors R1-R4 (i.e., the relationship R4 > R3 > R2 > R1) does not necessarily have to match that described above and depicted in FIG. 17B. For example, in some embodiments, some or all of the plurality of resistors R1-R4 may have substantially equal resistor values.In some embodiments, one or more of the plurality of resistors may have a higher resistance value than one or more of the resistors downstream therefrom in sequence.

[0138] Figure 18A illustrates an exemplary first electrode 1106-G1 of a controllable dimming system configured to polarize ambient light passing therethrough such that the controllable dimming assembly attenuates the ambient light according to the radial gradient dimming pattern G1 of Figure 12A. The exemplary first electrode 1106-G1 has four segments / portions S1, S2, S3, S4 arranged and shaped similarly to the first electrode 1106A depicted in Figure 17. Figure 18B illustrates an exemplary first electrode 1106-G2 of a controllable dimming system configured to polarize ambient light passing therethrough such that the controllable dimming assembly attenuates the ambient light according to the radial gradient dimming pattern G2 of Figure 12B. The exemplary first electrode 1106-G2 has four segments / portions S1, S2, S3, S4 like the first electrode 1106A depicted in Figure 17; however, the four segments / portions S1, S2, S3, S4 are shaped differently than the corresponding segments in the first electrode 1106A depicted in Figure 17. Figure 18C illustrates an exemplary first electrode 1106-G3 of a controllable dimming system configured to polarize ambient light passing therethrough such that the controllable dimming assembly attenuates the ambient light according to the linear gradient dimming pattern G3 of Figure 12C. The exemplary first electrode 1106-G3 has four segments / portions S1, S2, S3, S4 like the first electrode 1106A depicted in Figure 17; however, the four segments / portions S1, S2, S3, S4 are shaped differently than the corresponding segments in the first electrode 1106A depicted in Figure 17. Figure 18D illustrates an exemplary first electrode 1106-G4 of a controllable dimming system configured to polarize ambient light passing therethrough such that the controllable dimming assembly attenuates the ambient light according to the radial gradient dimming pattern G4 of Figure 12D. The exemplary first electrode 1106-G3 has four sections / portions S1, S2, S3, S4 like the first electrode 1106A depicted in FIG. 17, however, the four sections / portions S1, S2, S3, S4 are shaped and positioned differently than the corresponding sections in the first electrode 1106A depicted in FIG. 17.

[0139] The controllable dimming assembly and its various components described above include a specific number of sections / parts with a specific shape, but these numbers and shapes are for illustration only. The number and shape of the sections / parts can vary while remaining within the scope of the present disclosure. Various mechanisms for controllably dimming have been described above independently, but the scope of the present disclosure includes combinations and sub-combinations of the mechanisms described above. For example, the polarizer depicted in FIGS. 13A - 13D can be combined with the electrodes depicted in FIGS. 14, 15, and 17A. The controllable dimming assembly described above enables a stepwise attenuation of light passing through the controllable dimming assembly with the application of a number (e.g., 1 or 2) volts. This simple activation mechanism simplifies light attenuation for an AR system, which can activate a stepwise light attenuation in response to the detected intensity and / or direction of ambient light.

[0140] As described above with reference to FIG. 11, in some embodiments, the controllable dimming system may drive the dimming assembly to effect an adjustment of the opacity at a global level of a spatially varying dimming pattern (e.g., a gradient dimming pattern) over time based on any of a variety of different factors. In some implementations, such factors may include inputs received from one or more data sources. That is, in some implementations, the controllable dimming system may drive or otherwise adjust the amount of voltage applied to the dimming assembly based on inputs received from one or more data sources. Examples of such one or more data sources may include sensing devices, user interface components, display system components, network-accessible resources, and the like.

[0141] For example, in some embodiments, the controllable dimming system may include one or more ambient light sensors (e.g., photodiodes, imaging sensors, etc.) configured to measure the intensity of ambient light incident thereon, and may adjust in real time the amount of voltage applied to the dimming assembly based on data received from the one or more ambient light sensors. In some examples, the controllable dimming system may include one or more user interface components (e.g., a handheld controller, buttons, dials, touch pads, microphones, cameras, and other components through which user input may be provided), and may adjust the amount of voltage applied to the dimming assembly based on data received from such one or more user interface components. In this way, the user may interact with such one or more user interface components (e.g., using touch input, voice input, gesture input, etc.) and may be able to adjust the dimming assembly according to their preferences. In some embodiments, the controllable dimming system may adjust the amount of voltage applied to the dimming assembly based on data received from one or more display system components, such as one or more processing units, configured to generate, render, and present virtual content. In some implementations, the controllable dimming system may adjust the amount of voltage applied to the dimming assembly based on data received from one or more resources via one or more communication networks, such as websites, cloud computing systems, remotely located computing and / or sensing devices, and the like.

[0142] In some embodiments, the controllable dimming system may adjust the amount of voltage applied to the dimming assembly based on inputs received from a plurality of data sources, including one or more sensing devices, one or more user interface components, one or more display system components, one or more network-accessible resources, or combinations thereof. Additional examples of such data sources and dimming assembly control schemes are described in further detail in U.S. Patent Application No. 16 / 557,706, which is hereby incorporated by reference in its entirety. In some implementations, one or more of the foregoing data sources and / or dimming system control schemes may be employed in one or more of the systems and techniques described herein.

[0143] The AR system described above is provided as an example of various optical systems that can enjoy the advantages from more selectively and controllably transmissive optical elements. Thus, the use of the optical systems described herein is not limited to the disclosed AR system, but rather is applicable to any optical system. In fact, although mainly described in the context of AR and VR display systems, it should be understood that one or more of the systems and techniques described herein may also be utilized in various other paradigms and settings. For example, in some implementations, one or more of the systems and techniques described herein may be employed in any of various other types of eyewear, such as prescription glasses, sunglasses, safety glasses, swimming goggles, and the like, and in any of various other types of wearable gear that may include visors, face masks, and / or protective shields, such as helmets (e.g., football helmets, hockey helmets, motorcycle helmets, etc.), ski and snowboard goggles, paintball masks, and the like. For example, in some embodiments, two controllable dimming assemblies are employed in one of the aforementioned types of eyewear, and when the eyewear is worn by a user, the two controllable dimming assemblies may be configured to be positioned in front of and aligned with the user's both eyes, such as in the form of a pair of eyepieces. Further, in other embodiments, a single relatively wide controllable dimming assembly is employed in one of the aforementioned types of wearable gear, and when the wearable gear is worn by a user, the controllable dimming assembly may be configured to be positioned in front of the user's both eyes in a manner similar to that of a visor, face mask, or shield. In these embodiments, the controllable dimming assembly may in fact serve as a visor, face mask, or shield of the wearable gear, or may be physically coupled to the visor, face mask, or shield of the wearable gear.

[0144] Additional examples are provided below.

[0145] Example 1: A head-mounted device, comprising: a frame configured to be worn around a user's head of the head-mounted device; a controllable dimming assembly physically coupled to the frame so as to be positioned between the user's eyes and the user's environment when the head-mounted device is worn by the user, the controllable dimming assembly being configured to exhibit a level of opacity that varies from a first level of opacity to a second level of opacity as a function of a location on the controllable dimming assembly; and a control circuitry electrically coupled to the controllable dimming assembly and configured to apply one or more electrical signals to the controllable dimming assembly to adjust one or both of the first and second levels of opacity.

[0146] Example 2: The head-mounted device according to Example 1, wherein the controllable dimming assembly is configured to exhibit (i) a first level of opacity at a first location on the controllable dimming assembly and (ii) a level of opacity that varies as a function of the distance from the first location on the controllable dimming assembly.

[0147] Example 3: The head-mounted device according to Example 2, wherein the controllable dimming assembly is configured to exhibit a second level of opacity at a second location on the controllable dimming assembly, the second location being different from the first location.

[0148] Example 4: The head-mounted device according to Example 2, wherein the first location or the second location corresponds to a set of one or more points along at least a portion of the outer periphery of the controllable dimming assembly.

[0149] Example 5: The head-mounted device according to Example 2, wherein the first location corresponds to a location within the inner region of the controllable dimming assembly.

[0150] Example 6: The head-mounted device according to Example 2, wherein the location within the inner region of the controllable dimming assembly corresponds to the center of the controllable dimming assembly.

[0151] Example 7: The head-mounted device according to Example 1, wherein the first opacity level represents the global minimum opacity level and the second opacity level represents the global maximum opacity level.

[0152] Example 8: The head-mounted device according to Example 1, wherein the controllable dimming assembly is configured to exhibit an opacity level that varies linearly, exponentially, or logarithmically as a function of a location on the controllable dimming assembly.

[0153] Example 9: The head-mounted device according to Example 1, wherein the controllable dimming assembly is configured such that the first opacity level and the second opacity level vary based on the voltage level of one or more electrical signals applied as an input to the controllable dimming assembly.

[0154] Example 10: The head-mounted device according to Example 9, wherein the controllable dimming assembly is configured such that the first opacity level and the second opacity level change at different rates as the voltage level changes.

[0155] Example 11: The head-mounted device according to Example 1, wherein the controllable dimming assembly includes a first and a second polarizer, a first and a second electrode assembly disposed between the first polarizer and the second polarizer, and a liquid crystal layer disposed between the first electrode assembly and the second electrode assembly.

[0156] Example 12: The head-mounted device according to Example 11, wherein one or both of the first and second polarizers are configured to impart a spatially varying degree of polarization to light passing therethrough.

[0157] Example 13: A head-mounted device as described in Example 11, wherein the control circuitry is electrically coupled to the first and second electrode assemblies and configured to apply one or more electrical signals to the controllable dimming assembly to generate an electric field between the first electrode assembly and the second electrode assembly.

[0158] Example 14: A head-mounted device as described in Example 13, wherein the controllable dimming assembly is configured to produce an electric field between the first electrode assembly and the second electrode assembly, the electric field exhibiting a spatially varying level of electric field strength.

[0159] Example 15: A head-mounted device as described in Example 13, wherein one or both of the first and second electrode assemblies are configured to have one or more properties thereof spatially varied.

[0160] Example 16: The head-mounted device of Example 15, wherein the one or more properties include thickness, resistance, conductivity, orientation, position, composition, or a combination thereof.

[0161] Example 17: The head-mounted device of Example 1, wherein the control circuitry comprises one or more of a voltage divider network, conductors, a processor, and a power supply.

[0162] Example 18: A head-mounted device as described in Example 1, wherein the controllable dimming assembly is physically coupled to the frame so that when the head-mounted device is worn by a user, it is positioned between the user's eyes and the user's environment.

[0163] Example 19: The control circuitry is further configured to receive inputs from one or more data sources, apply one or more electrical signals to a controllable dimming assembly, and adjust one or both of the first and second opacity levels. To do so, the control circuitry is configured to apply one or more electrical signals to the controllable dimming assembly based on inputs received from one or more data sources and adjust one or both of the first and second opacity levels, the head-mounted device according to Example 1.

[0164] Example 20: The one or more data sources include one or more sensing devices, user interface components, display system components, network-accessible resources, or combinations thereof, the head-mounted device according to Example 19.

[0165] Various exemplary embodiments of the present invention are described herein. These examples are referred to in a non-limiting sense. They are provided to illustrate more broadly applicable aspects of the present invention. Various changes may be made to the invention described, and equivalents may be substituted without departing from the true spirit and scope of the invention. Additionally, many modifications may be made to adapt a particular situation, material, composition of matter, process, process act, or step to the objectives, spirit, or scope of the present invention. Further, as will be understood by those skilled in the art, each of the individual variations described and illustrated herein can be readily separated from or combined with features of any of the other several embodiments without departing from the scope or spirit of the present invention. All such modifications are intended to be within the scope of the claims associated with this disclosure.

[0166] The present invention includes a method that can be implemented using a target device. The method may include the act of providing such a suitable device. Such provision may be performed by an end user. In other words, the act of "providing" simply requires that the end user acts to obtain, access, approach, locate, configure, activate, power on, or otherwise provide the device required in the method of the present subject matter. The methods described herein may be performed in any order of the described events that is logically possible, and in the order in which the events are described.

[0167] Exemplary aspects of the present invention are described above, along with details regarding material selection and manufacturing. Regarding other details of the present invention, these are to be understood in relation to the patents and publications referenced above and are generally known or understandable by those skilled in the art. The same may apply to the method-based aspects of the present invention from the perspective of additional acts that are generally or logically employed.

[0168] In addition, although the present invention has been described with reference to several embodiments that optionally incorporate various features, the present invention is not limited to what is described and indicated as contemplated for each variation of the present invention. Various changes may be made to the described invention, and equivalents (whether or not described herein and whether included for the sake of brevity) may be substituted without departing from the true spirit and scope of the present invention. Additionally, when a range of values is provided, it is to be understood that all intervening values between the upper and lower limits of that range, and any other defined or intervening values within that defined range, are included within the present invention.

[0169] It is also contemplated that any optional features of the described variations of the present invention may be described and claimed independently or in combination with any one or more of the features described herein. References to items in the singular include the possibility that there are plural identical items. More specifically, as used herein and in the claims associated herewith, the singular forms "a", "an", "said", and "the" include the referents in the plural unless specifically stated otherwise. In other words, the use of the articles enables "at least one" of the item in question in the above description and the claims associated with this disclosure. Further, note that such claims may be drafted to exclude any optional elements. Accordingly, this description serves the purpose of acting as a preamble for the use of such exclusive terms as "solely", "only", and equivalents, or the use of "negative" limitations, in relation to the recitation of elements of the claims.

[0170] Without using such exclusive terms, the term "comprising" in the claims associated with this disclosure shall be taken to enable the inclusion of any additional elements, whether or not a given number of elements are recited in such claims or the addition of features can be regarded as a transformation of the nature of the elements recited in such claims. Unless specifically defined herein, all technical and scientific terms used herein are to be given the broadest generally understood meaning possible while maintaining the validity of the claims.

[0171] The scope of the present invention is not limited to the provided examples and / or the specification of the subject matter, but rather is limited only by the scope of the language of the claims associated with this disclosure.

[0172] In the foregoing specification, the present invention has been described with reference to its specific embodiments. However, it will be apparent that various modifications and changes may be made thereto without departing from the broader spirit and scope of the present invention. For example, the foregoing process flow is described with reference to a particular order of process actions. However, many of the orders of the described process actions may be changed without affecting the scope or operation of the present invention. The specification and drawings are, therefore, to be regarded in an illustrative rather than a limiting sense.

Claims

1. A head-mounted device, comprising: a frame configured to be worn around a user's head of the head-mounted device; a controllable dimming assembly physically coupled to the frame in a manner positioned between the user's eyes and the user's environment when the head-mounted device is worn by the user, the controllable dimming assembly comprising a first electrode assembly including a first electrode, a second electrode assembly including a second electrode, a first polarizer, a second polarizer, and a liquid crystal layer, the first and second electrode assemblies being disposed between the first and second polarizers, the liquid crystal layer being disposed between the first and second electrode assemblies, the first and second electrodes being configured to produce an electric field having a spatially varying level of electric field strength between the first and second electrode assemblies, the controllable dimming assembly being configured to exhibit a level of opacity varying from a first level of opacity to a second level of opacity as a function of a location on the controllable dimming assembly, and at least one of the first and second polarizers being configured to impart a spatially varying degree of polarization to light passing therethrough; a control network electrically coupled to the first and second electrodes of the controllable dimming assembly, the control network being configured to produce the electric field between the first and second electrode assemblies and to adjust one or both of the first and second levels of opacity by applying one or more electrical signals to the first and second electrodes; a device.

2. The controllable dimming assembly is configured to exhibit: the first level of opacity at a first location on the controllable dimming assembly; and a level of opacity varying as a function of the distance from the first location on the controllable dimming assembly. The controllable dimming assembly is further configured to exhibit the second level of opacity at a second location on the controllable dimming assembly, the second location being different from the first location. ​ The device according to claim 1, wherein the second location corresponds to a set of one or more points along at least a portion of the outer periphery of the controllable dimming assembly.

3. The device according to claim 2, wherein the first location corresponds to a set of one or more points along at least a portion of the outer periphery of the controllable dimming assembly.

4. The first location corresponds to a location within an inner region of the controllable dimming assembly, The device according to claim 2, wherein the location within the inner region of the controllable dimming assembly corresponds to the center of the controllable dimming assembly.

5. The device according to claim 1, wherein the first opacity level represents the minimum opacity level on the controllable dimming assembly, and the second opacity level represents the maximum opacity level on the controllable dimming assembly.

6. The device according to claim 1, wherein the controllable dimming assembly is configured to exhibit an opacity level that varies linearly, exponentially, or logarithmically as a function of a location on the controllable dimming assembly.

7. The controllable dimming assembly is configured such that the first opacity level and the second opacity level vary based on the level of voltage of one or more electrical signals applied as an input to the controllable dimming assembly, The device according to claim 1, wherein the controllable dimming assembly is configured such that the first opacity level and the second opacity level change at different rates as the level of the voltage changes.

8. The device according to claim 1, wherein the controllable dimming assembly is configured to produce an electric field having a spatially varying level of electric field strength between the first electrode assembly and the second electrode assembly.

9. The device according to claim 1, wherein the control circuitry comprises one or more of a voltage divider network, a conductor, a processor, and a power supply.

10. The device according to claim 1, wherein the controllable dimming assembly is physically coupled to the frame in such a manner that when the head-mounted device is worn by the user, it is positioned between both eyes of the user and the user's environment.

11. The control circuit network receives an input from a data source, and adjusts at least one of the first and second opacity levels based on the input received from the data source by applying one or more electrical signals to the controllable dimming assembly and is further configured to perform The data source comprises a sensing device, the device according to claim 1. **Claim 12** The data source comprises a user interface component, a display system component, a network-accessible resource, or a combination thereof, the device according to claim 11. **Claim 13** The control circuit network receives inputs from a plurality of data sources, and adjusts at least one of the first and second opacity levels based on the inputs received from the plurality of data sources by applying one or more electrical signals to the controllable dimming assembly and is further configured to perform, the device according to claim 1. **Claim 14** The plurality of data sources includes a sensing device and one or more of a user interface component, a display system component, and a network-accessible resource, the device according to claim 13. **Claim 15** The plurality of data sources includes at least two of a user interface component, a display system component, and a network-accessible resource, the device according to claim 14. **Claim 16** The thickness, resistance, conductivity, composition, or a combination thereof of one or both of the first and second electrode assemblies varies spatially, the device according to claim 1. **Claim 17** The first electrode comprises a non-uniform multi-segment electrode, and the second electrode comprises a uniform electrode, the device according to claim 1. **Claim 18** The first electrode and the second electrode are parallel to each other and are planar electrodes disposed on both sides of the liquid crystal layer, the device according to claim 17. **Claim 19** The first electrode comprises a first or upper electrode portion, a second electrode portion, and a third or bottom electrode, and the second electrode portion is disposed between the first or upper electrode portion and the third or bottom electrode portion, the device according to claim 17. **Claim 20** The control circuit network is electrically coupled to the first and second electrode assemblies and is configured to produce a non-uniform electric field between the first electrode assembly and the second electrode assembly and non-uniform light attenuation within the liquid crystal layer by applying one or more electrical signals to the controllable dimming assembly. The device according to claim 1.

21. The controllable dimming assembly comprises a single component configured as a visor, mask, or shield positioned between the user's eyes and the user's environment when the head-mounted device is worn by the user. The device according to claim 1.

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