3D object rendering using detected features

Abstract

To provide 3D object rendering using detected suitable features.SOLUTION: An augmented reality display system is configured to use fiducial markers to align 3D content with real objects. The augmented reality display system can optionally include a depth sensor configured to detect a location of a real object. The augmented reality display system can also include a light source configured to illuminate at least a portion of the object with invisible light, and a light sensor configured to form an image using a reflected portion of the invisible light. Processing circuitry of the display system can identify a location marker based on the difference between the emitted light and the reflected light and determine an orientation of the real object based on the location of the real object and a location of the location marker.SELECTED DRAWING: Figure 10

Description

[Technical field]

[0001] (Incorporated by reference) This application claims priority under 35 USC § 119(e) from U.S. Provisional Application No. 62 / 433,767, filed December 13, 2016, entitled "3D OBJECT RENDERING USING DETECTED FEATURES," which is incorporated herein by reference in its entirety for all purposes. This application further incorporates by reference the entirety of each of the following patent applications: U.S. Application No. 14 / 555,585, filed November 27, 2014; U.S. Application No. 14 / 690,401, filed April 18, 2015; U.S. Application No. 14 / 212,961, filed March 14, 2014; U.S. Application No. 14 / 331,218, filed July 14, 2014; and U.S. Application No. 15 / 072,290, filed March 16, 2016.

[0002] The present disclosure relates to optical devices, including virtual reality and augmented reality imaging and visualization systems. [Background technology]

[0003] Modern computing and display technologies have facilitated the development of systems for so-called "virtual reality" or "augmented reality" experiences, in which digitally reproduced images or portions thereof are presented to a user in a manner that appears or may be perceived as real. Virtual reality, or "VR", scenarios typically involve the presentation of digital or virtual image information without transparency to other actual real-world visual inputs, while 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. Mixed reality or "MR" scenarios are a type of AR scenario that typically involve virtual objects that are integrated into and respond to the natural world. For example, in MR scenarios, AR image content may be blocked by or otherwise perceived to interact with objects in the real world.

[0004] 1, an augmented reality scene 10 is depicted in which a user of the AR technology sees a real-world park-like setting 20 featuring people, trees, buildings in the background, and a concrete platform 30. In addition to these items, the user of the AR technology also perceives that they are "seeing" "virtual content," such as a robotic figure 40 standing on the real-world platform 30 and a flying cartoon-like avatar character 50 that appears to be an anthropomorphic bumblebee, although these elements 40, 50 do not exist in the real world. The human visual perception system is complex, making it difficult to create AR technology that facilitates a comfortable, natural-feeling, and rich presentation of virtual image elements among other virtual or real-world image elements.

[0005] The systems and methods disclosed herein address various challenges associated with AR and VR technologies. Summary of the Invention [Means for solving the problem]

[0006] The details of one or more embodiments of the subject matter described herein are set forth in the accompanying drawings and the following description. Other features, aspects, and advantages will become apparent from the description, drawings, and claims. Neither this summary nor the following detailed description purports to define or limit the scope of the inventive subject matter. (Example) 1. An augmented reality display system configured to align 3D content with real objects, the system comprising: a frame configured to mount on a wearer; an augmented reality display mounted to the frame and configured to direct images to an eye of the wearer; a light source configured to illuminate at least a portion of an object by emitting invisible light; a light sensor configured to use the invisible light to image the portion of the object illuminated by the light source; a processing circuit configured to determine information regarding a location of the object, an orientation of the object, or both, based on one or more characteristics of a feature in an image formed using the reflected portion of the invisible light; and A system comprising: 2. The augmented reality display system of example 1, wherein features in the image formed using the reflected portion of the invisible light are invisible to the eye. 3. The augmented reality display system of any of Examples 1-2, wherein the invisible light comprises infrared light. 4. An augmented reality display system as described in any of Examples 1-3, wherein the invisible light emitted by the light source comprises a beam that forms a spot on the portion of the object. 5. The augmented reality display system of any of Examples 1-3, wherein the invisible light emitted by the light source comprises a light pattern. 6. The augmented reality display system of any of Examples 1-5, wherein the characteristics include a location of the feature. 7. The augmented reality display system of any of Examples 1-6, wherein the characteristics include a shape of the feature. 8. The augmented reality display system of any of Examples 1-7, wherein the characteristic comprises an orientation of the feature. 9. An augmented reality display system as described in any of Examples 1-8, further comprising a depth sensor configured to detect the location of a real object within the world. 10. An augmented reality display system as described in any of Examples 1-9, wherein the processing circuit is configured to determine a difference between the distribution of the emitted invisible light and the distribution of the reflected portion of the invisible light. 11. The augmented reality display system of Example 10, wherein the processing circuit is configured to identify a difference signature based on the determined difference. 12. The augmented reality display system of Example 11, wherein the processing circuit is configured to determine an orientation of the real object based on the location of the real object and the location of the difference signature. 13. The augmented reality display system of Example 12, wherein the processing circuit is configured to determine a location of a real object based, at least in part, on the location of the difference signature. 14. An augmented reality display system as described in any of Examples 1-13, further comprising an eyepiece disposed on the frame, at least a portion of the eyepiece being transparent and positioned in a location in front of the wearer's eye when the wearer wears the display system so as to transmit light from an environment in front of the wearer to the wearer's eye and provide a view of the environment in front of the wearer. 15. An augmented reality display system, comprising: a frame configured to mount on a wearer; an augmented reality display mounted to the frame and configured to direct images to an eye of the wearer; a depth sensor configured to map a surface of a real object within a field of view of the wearer; a light source configured to project light at least at a first wavelength incident on a surface of a real object; a light detector configured to form an image using a portion of the light reflected by a surface of the real object; a processing circuit configured to determine a light difference marker based at least in part on the reflected portion of the light pattern and to render a virtual object at a fixed displacement relative to the light difference marker; An augmented reality display system comprising: 16. Rendering a virtual object at a fixed displacement relative to a light difference marker receiving an initial location for rendering a virtual object relative to a real object at an initial time; determining a fixation displacement based on a distance between the initial location and the optical difference marker; detecting a subsequent location of the optical difference marker at a time subsequent to the initial time; Rendering the virtual object at a fixed displacement relative to the detected subsequent location of the optical difference marker; 16. The augmented reality display system of claim 15, comprising: 17. The augmented reality display system of Example 15 or 16, further comprising an eyepiece disposed on the frame, at least a portion of the eyepiece being transparent and positioned in a location in front of the wearer's eye when the wearer wears the display system so as to transmit light from an environment in front of the wearer to the wearer's eye and provide a view of the environment in front of the wearer. 18. An augmented reality display system configured to match 3D content with real objects, the system comprising: a frame configured to mount on a wearer; an augmented reality display mounted to the frame and configured to direct images to an eye of the wearer; a depth sensor configured to map a surface of a real object within a field of view of the wearer; a light source configured to emit light to illuminate at least a portion of the object; a light sensor configured to use the emitted light to image the portion of the object illuminated by the light source; a processing circuit configured to determine information regarding a location of a real object, an orientation of a real object, or both, based on one or more characteristics of features in the image of the object; A system comprising: 19. The augmented reality display system of Example 18, wherein the light emitted by the light source comprises a beam that forms a spot on the portion of the object. 20. The augmented reality display system of example 18, wherein the light emitted by the light source comprises a light pattern. 21. The augmented reality display system of any of Examples 18-20, wherein the characteristics include a location of the feature. 22. The augmented reality display system of any of Examples 18-21, wherein the characteristics include a shape of the feature. 23. The augmented reality display system of any of Examples 18-22, wherein the characteristic comprises an orientation of the feature. 24. An augmented reality display system as described in any of Examples 18-23, wherein the processing circuit is configured to determine a difference between the distribution of emitted light and the distribution of the emitted light reflected from the object. 25. The augmented reality display system of Example 24, wherein the processing circuit is configured to identify a light difference marker based on the determined difference. 26. The augmented reality display system of Example 25, wherein the processing circuit is configured to determine an orientation of the real object based on the location of the real object and the location of the optical difference marker. 27. The augmented reality display system of any one of Examples 25 to 26, wherein the processing circuit is configured to determine a location of a real object based, at least in part, on the location of the light difference marker. 28. An augmented reality display system as described in any of Examples 18-27, wherein the depth sensor comprises a laser or ultrasonic range finder. 29. An augmented reality display system as described in any of Examples 18-28, wherein the depth sensor comprises a camera. 30. An augmented reality display system as described in any of Examples 18-29, further comprising an eyepiece disposed on the frame, at least a portion of the eyepiece being transparent and positioned in a location in front of the wearer's eye when the wearer wears the display system so as to transmit light from an environment in front of the wearer to the wearer's eye and provide a view of the environment in front of the wearer. 31. The augmented reality display system of any of the previous embodiments, wherein the display is configured to render image content as if different image content were located at different depths. 32. The augmented reality display system of Example 31, wherein the display includes a multi-refractive power optical element having different refractive powers to provide the different depths. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 illustrates a user's view of an augmented reality (AR) device.

[0008] [Diagram 2] FIG. 2 illustrates an example of a wearable display system.

[0009] [Diagram 3] FIG. 3 illustrates a conventional display system for simulating a three-dimensional image for a user.

[0010] [Figure 4] FIG. 4 illustrates aspects of an approach for simulating a three-dimensional image using multiple depth planes.

[0011] [Diagram 5] 5A-5C illustrate the relationship between the radius of curvature and the radius of focus.

[0012] [Figure 6] FIG. 6 illustrates an embodiment of a waveguide stack for outputting image information to a user.

[0013] [Figure 7] FIG. 7 illustrates an example of an output beam output by a waveguide.

[0014] [Figure 8] FIG. 8 illustrates an example of a stacked waveguide assembly where each depth plane contains an image formed using multiple different primary colors.

[0015] [Figure 9A] FIG. 9A illustrates a cross-sectional side view of an embodiment of a set of stacked waveguides, each of which includes an internal coupling optical element.

[0016] [Figure 9B] FIG. 9B illustrates a perspective view of the multiple stacked waveguide embodiment of FIG. 9A.

[0017] [Figure 9C] FIG. 9C illustrates a top-down plan view of the multiple stacked waveguide embodiment of FIGS. 9A and 9B.

[0018] [Figure 10] FIG. 10 diagrammatically illustrates an augmented reality display system configured to track the orientation of objects in the world using markers.

[0019] [Figure 11] FIG. 11 illustrates an example method for using markers to track the orientation of an object in the world. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] Reference is now made to the figures, in which like reference numbers refer to like parts throughout. It should be understood that the embodiments disclosed herein generally include an optical system, including a display system. In some embodiments, the display system is wearable, which may advantageously provide a more immersive VR or AR experience. For example, a display containing one or more waveguides (e.g., a stack of waveguides) may be configured to be positioned and worn in front of a user's eyes or a viewer. In some embodiments, a stack of two waveguides (one for each eye of the viewer) may be utilized to provide a different image to each eye. Exemplary Display Systems

[0021] FIG. 2 illustrates an example of a wearable display system 60. The display system 60 includes a display 70 and various mechanical and electronic modules and systems to support the functionality of the display 70. The display 70 may be coupled to a frame 80, which is wearable by a display system user or viewer 90 and configured to position the display 70 in front of the eye of the user 90. The display 70 may be considered eyewear in some embodiments. In some embodiments, a speaker 100 is coupled to the frame 80 and configured to be positioned adjacent to the ear canal of the user 90 (in some embodiments, another speaker, not shown, may be positioned adjacent the user's other ear canal to provide stereo / shapeable sound control). In some embodiments, the display system may also include one or more microphones 110 or other devices to detect sound. In some embodiments, the microphones may be configured to allow the user to provide input or commands to the system 60 (e.g., voice menu command selections, natural language queries, etc.) and / or enable audio communication with other persons (e.g., other users of similar display systems). The microphone may further be configured as an ambient sensor to collect audio data (e.g., sounds from the user and / or the environment). In some embodiments, the display system may also include an ambient sensor 120a, which may be separate from the frame 80 and attached to the body of the user 90 (e.g., on the head, torso, limbs, etc. of the user 90). The ambient sensor 120a, in some embodiments, may be configured to obtain data characterizing a physiological state of the user 90. For example, the sensor 120a may be an electrode.

[0022] 2, the display 70 is operably coupled by a communication link 130, such as wired or wireless connectivity, to a local data processing module 140, which may be mounted in a variety of configurations, such as fixedly attached to the frame 80, fixedly attached to a helmet or hat worn by the user, built into headphones, or otherwise removably attached to the user 90 (e.g., in a backpack configuration, in a belt-coupled configuration). Similarly, the sensor 120a may be operably coupled to the local processor and data module 140 by a communication link 120b, such as wired or wireless connectivity. The local processing and data module 140 may include a hardware processor and digital memory, such as non-volatile memory (e.g., flash memory or hard disk drive), both of which may be utilized to aid in processing, caching, and storing data. The data includes a) data captured from sensors (e.g., which may be operatively coupled to the frame 80 or otherwise attached to the user 90), such as image capture devices (such as cameras), microphones, inertial measurement units, accelerometers, compasses, GPS units, wireless devices, gyroscopes, and / or other sensors disclosed herein, and / or b) data acquired and / or processed using the remote processing module 150 and / or remote data repository 160 (including data related to virtual content), possibly for passing to the display 70 after processing or reading. The local processing and data module 140 may be operatively coupled to the remote processing module 150 and the remote data repository 160 by communication links 170, 180, such as via wired or wireless communication links, such that these remote modules 150, 160 are operatively coupled to each other and available as resources to the local processing and data module 140.In some embodiments, local processing and data module 140 may include one or more of an image capture device, a microphone, an inertial measurement unit, an accelerometer, a compass, a GPS unit, a wireless device, and / or a gyroscope. In some other embodiments, one or more of these sensors may be mounted to frame 80 or may be a freestanding structure that communicates with local processing and data module 140 by a wired or wireless communication path.

[0023] 2, in some embodiments, remote processing module 150 may comprise one or more processors configured to analyze and process data and / or image information. In some embodiments, remote data repository 160 may comprise a digital data storage facility, which may be available through the Internet or other networking configurations in a "cloud" resource configuration. In some embodiments, remote data repository 160 may include one or more remote servers that provide information to local processing and data module 140 and / or remote processing module 150, e.g., information for generating augmented reality content. In some embodiments, all data is stored and all calculations are performed within the local processing and data module, allowing for fully autonomous use from the remote modules.

[0024] The perception of an image as "three-dimensional" or "3-D" may be achieved by providing a slightly different presentation of the image to each eye of a viewer. FIG. 3 illustrates a conventional display system for simulating a three-dimensional image for a user. Two distinct images 190, 200 (one for each eye 210, 220) are output to the user. The images 190, 200 are spaced apart from the eyes 210, 220 by a distance 230 along an optical axis or z-axis parallel to the viewer's line of sight. The images 190, 200 are flat and the eyes 210, 220 may focus on the images by assuming a single accommodated state. Such a 3-D display system relies on the human visual system to combine the images 190, 200 and provide a perception of depth and / or scale of the combined image.

[0025] However, it should be appreciated that the human visual system is more complex and more difficult to provide a realistic perception of depth. For example, many viewers of conventional "3-D" display systems may find such systems uncomfortable or may not perceive any sensation of depth at all. Without being limited by theory, it is believed that a viewer of an object may perceive the object as "three-dimensional" due to a combination of vergence and accommodation. Vergence of the two eyes relative to one another (i.e., rotation of the eyes such that the pupils move toward or away from one another, converging the line of sight of the eyes to fixate on an object) is closely linked to the focusing (or "accommodation") of the eye's lenses and pupils. Under normal conditions, a change in focus of the eye's lenses or accommodation of the eye to change focus from one object to another at a different distance will automatically produce a matching change in vergence at the same distance, a relationship known as the "accommodation-vergence-divergence reflex" and pupil dilation or constriction. Similarly, changes in vergence-divergence will induce matching changes in accommodation of the lens shape and pupil size under normal conditions. As described herein, many stereoscopic or "3-D" display systems display a scene using a slightly different presentation (and therefore a slightly different image) to each eye so that a three-dimensional perspective is perceived by the human visual system. However, such systems are uncomfortable for many viewers because, among other things, they simply provide a different presentation of the scene, but work against the "accommodation-vergence-divergence reflex" when the eyes view the entire image information in a single accommodated state. Display systems that provide better matching between accommodation and vergence-divergence may form a more realistic and comfortable simulation of a three-dimensional image, contributing to increased wear duration and therefore compliance with diagnostic and therapeutic protocols.

[0026] FIG. 4 illustrates aspects of an approach for simulating a three-dimensional image using multiple depth planes. With reference to FIG. 4, objects at various distances from the eyes 210, 220 on the z-axis are accommodated by the eyes 210, 220 such that the objects are in focus. The eyes 210, 220 assume a particular accommodated state and focus objects at different distances along the z-axis. As a result, a particular accommodated state may be said to be associated with a particular one of the depth planes 240 having an associated focal length such that an object or part of an object at a particular depth plane is in focus when the eye is in an accommodated state relative to that depth plane. In some embodiments, a three-dimensional image may be simulated by providing a different presentation of an image for each eye 210, 220, and by providing a different presentation of an image corresponding to each of the depth planes. Although shown as separate for clarity of illustration, it should be understood that the fields of view of the eyes 210, 220 may overlap, for example, as the distance along the z-axis increases. Additionally, while shown to be flat for ease of illustration, it should be understood that the contour of the depth plane may be curved in physical space such that all features within the depth plane are in focus with the eye in a particular accommodated state.

[0027] The distance between an object and the eye 210 or 220 may also change the amount of divergence of light from that object as viewed by that eye. Figures 5A-5C illustrate the relationship between distance and divergence of light rays. The distance between the object and the eye 210 is represented in the order of decreasing distances R1, R2, and R3. As shown in Figures 5A-5C, the light rays become more divergent as the distance to the object decreases. As the distance increases, the light rays become more collimated. In other words, the light field generated by a point (an object or part of an object) may be said to have a spherical wavefront curvature that is a function of the distance the point is away from the user's eye. The curvature increases with decreasing distance between the object and the eye 210. As a result, at different depth planes, the divergence of the light rays is also different, and the divergence increases with decreasing distance between the depth plane and the viewer's eye 210. Although only a monocular 210 is illustrated in FIGS. 5A-5C and other figures herein for clarity of illustration, it should be understood that the discussion regarding eye 210 may apply to both eyes 210 and 220 of a viewer.

[0028] Without being limited by theory, it is believed that the human eye is typically capable of interpreting a finite number of depth planes to provide depth perception. As a result, a highly realistic simulation of perceived depth may be achieved by providing the eye with different presentations of images corresponding to each of these limited number of depth planes. The different presentations may be focused separately by the viewer's eye, thereby serving to provide depth cues to the user based on the ocular accommodation required to focus on different image features for a scene located on the different depth planes and / or based on the observation of different image features on the different depth planes that are out of focus.

[0029] FIG. 6 illustrates an example of a waveguide stack for outputting image information to a user. The display system 250 includes a stack of waveguides or a stacked waveguide assembly 260 that may be utilized to provide a three-dimensional perception to the eye / brain using multiple waveguides 270, 280, 290, 300, 310. In some embodiments, the display system 250 is the system 60 of FIG. 2, of which FIG. 6 illustrates several portions in more detail. For example, the waveguide assembly 260 may be part of the display 70 of FIG. 2. It should be understood that the display system 250 may be considered a light field display in some embodiments.

[0030] Continuing with reference to FIG. 6, the waveguide assembly 260 may also include a number of features 320, 330, 340, 350 between the waveguides. In some embodiments, the features 320, 330, 340, 350 may be one or more lenses. The waveguides 270, 280, 290, 300, 310 and / or the number of lenses 320, 330, 340, 350 may be configured to transmit image information to the eye with various levels of wavefront curvature or light beam divergence. Each waveguide level may be associated with a particular depth plane and may be configured to output image information corresponding to that depth plane. The image input devices 360, 370, 380, 390, 400 may act as light sources for the waveguides and may be utilized to input image information into the waveguides 270, 280, 290, 300, 310, each of which may be configured to distribute incident light across each individual waveguide for output towards the eye 210, as described herein. Light exits output surfaces 410, 420, 430, 440, 450 of the image input devices 360, 370, 380, 390, 400 and is input into corresponding input surfaces 460, 470, 480, 490, 500 of the waveguides 270, 280, 290, 300, 310. In some embodiments, each of the input surfaces 460, 470, 480, 490, 500 may be an edge of the corresponding waveguide or may be a portion of the major surface of the corresponding waveguide (i.e., one of the waveguide surfaces that directly faces the world 510 or the viewer's eye 210). In some embodiments, a single beam of light (e.g., a collimated beam) may be launched into each waveguide, outputting a total field of cloned collimated beams that are directed towards the eye 210 at a particular angle (and divergence) corresponding to the depth plane associated with the particular waveguide. In some embodiments, a single one of the image launch devices 360, 370, 380, 390, 400 may be associated with and launch light into multiple (e.g., three) waveguides 270, 280, 290, 300, 310.

[0031] In some embodiments, each of the image input devices 360, 370, 380, 390, 400 is a discrete display that generates image information for input into a corresponding waveguide 270, 280, 290, 300, 310. In some other embodiments, the image input devices 360, 370, 380, 390, 400 are the output of a single multiplexed display that may, for example, send image information to each of the image input devices 360, 370, 380, 390, 400 via one or more optical conduits (such as fiber optic cables). It should be understood that the image information provided by the image input devices 360, 370, 380, 390, 400 may include light of different wavelengths or colors (e.g., different primary colors as discussed herein).

[0032] In some embodiments, the light injected into the waveguides 270, 280, 290, 300, 310 is provided by a light projector system 520, which includes a light module 530, which may include a light emitter such as a light emitting diode (LED). Light from the light module 530 may be directed and modified by a light modulator 540, e.g., a spatial light modulator, via a beam splitter 550. The light modulator 540 may be configured to change the perceived intensity of the light injected into the waveguides 270, 280, 290, 300, 310. Examples of spatial light modulators include liquid crystal displays (LCDs), including liquid crystal on silicon (LCOS) displays.

[0033] In some embodiments, the display system 250 may be a scanning fiber display comprising one or more scanning fibers configured to project light in various patterns (e.g., raster scan, spiral scan, Lissajous pattern, etc.) into one or more waveguides 270, 280, 290, 300, 310 and ultimately to the viewer's eye 210. In some embodiments, the illustrated image injection devices 360, 370, 380, 390, 400 may represent diagrammatically a single scanning fiber or a bundle of scanning fibers configured to inject light into one or more waveguides 270, 280, 290, 300, 310. In some other embodiments, the illustrated image injection devices 360, 370, 380, 390, 400 may represent diagrammatically multiple scanning fibers or multiple bundles of scanning fibers, each of which is configured to inject light into an associated one of the waveguides 270, 280, 290, 300, 310. It is understood that one or more optical fibers may be configured to transmit light from the optical module 530 to one or more of the waveguides 270, 280, 290, 300, 310. It is understood that one or more intervening optical structures may be provided between the scanning fiber(s) and one or more of the waveguides 270, 280, 290, 300, 310, for example, to redirect light exiting the scanning fiber into one or more of the waveguides 270, 280, 290, 300, 310.

[0034] The controller 560 controls the operation of one or more of the stacked waveguide assemblies 260, including the operation of the image input devices 360, 370, 380, 390, 400, the light source 530, and the light modulator 540. In some embodiments, the controller 560 is part of the local data processing module 140. The controller 560 includes programming (e.g., instructions in a non-transient medium) that coordinates the timing and provisioning of image information to the waveguides 270, 280, 290, 300, 310, for example, according to any of the various schemes disclosed herein. In some embodiments, the controller may be a single integrated device or a distributed system connected by wired or wireless communication channels. The controller 560 may be part of the processing module 140 or 150 (FIG. 2) in some embodiments.

[0035] Continuing with reference to FIG. 6, the waveguides 270, 280, 290, 300, 310 may be configured to propagate light within each individual waveguide by total internal reflection (TIR). Each of the waveguides 270, 280, 290, 300, 310 may be planar or have another shape (e.g., curved) with major top and bottom surfaces and edges extending between the major top and bottom surfaces. In the illustrated configuration, each of the waveguides 270, 280, 290, 300, 310 may include out-coupling optical elements 570, 580, 590, 600, 610 configured to extract light from the waveguides by redirecting the light to propagate within each individual waveguide and outputting image information from the waveguides to the eye 210. The extracted light may also be referred to as out-coupled light, and the optical elements that out-couple light may also be referred to as light extraction optical elements. The extracted beam of light may be output by the waveguide at a location where the light propagating within the waveguide strikes the light extraction optical element. The outcoupling optical element 570, 580, 590, 600, 610 may be a grating, for example, including diffractive optical features as further discussed herein. Although shown disposed on the bottom major surface of the waveguide 270, 280, 290, 300, 310 for ease of explanation and clarity of drawing, in some embodiments the outcoupling optical element 570, 580, 590, 600, 610 may be disposed on the top major surface and / or bottom major surface and / or directly within the volume of the waveguide 270, 280, 290, 300, 310 as further discussed herein. In some embodiments, the outcoupling optical elements 570, 580, 590, 600, 610 may be formed within a layer of material that is attached to a transparent substrate and forms the waveguide 270, 280, 290, 300, 310. In some other embodiments, the waveguide 270, 280, 290, 300, 310 may be a monolithic piece of material and the outcoupling optical elements 570, 580, 590, 600, 610 may be formed on and / or within that piece of material.

[0036] With continued reference to FIG. 6, as discussed herein, each waveguide 270, 280, 290, 300, 310 is configured to output light and form an image corresponding to a particular depth plane. For example, the waveguide 270 closest to the eye may be configured to deliver collimated light (injected into such waveguide 270) to the eye 210. The collimated light may represent an optical infinity focal plane. The next upper waveguide 280 may be configured to send collimated light that passes through a first lens 350 (e.g., a negative lens) before it can reach the eye 210. Such first lens 350 may be configured to generate a slight convex wavefront curvature such that the eye / brain interprets the light originating from the next upper waveguide 280 as originating from a first focal plane closer inward from optical infinity toward the eye 210. Similarly, the third upper waveguide 290 passes its output light through both the first lens 350 and the second lens 340 before reaching the eye 210. The combined refractive powers of the first lens 350 and the second lens 340 may be configured to produce another incremental amount of wavefront curvature such that the eye / brain interprets the light emerging from the third waveguide 290 as emerging from a second focal plane that is closer inward from optical infinity towards the person than was the light from the next upper waveguide 280.

[0037] The other waveguide layers 300, 310 and lenses 330, 320 are similarly configured, with the highest waveguide 310 in the stack sending its output through all of the lenses between it and the eye for an aggregate focal power that represents the focal plane closest to the person. To compensate the stack of lenses 320, 330, 340, 350 when viewing / interpreting light originating from the world 510 on the other side of the stacked waveguide assembly 260, a compensating lens layer 620 may be placed on top of the stack to compensate for the aggregate power of the lens stacks 320, 330, 340, 350 below. Such a configuration provides as many perceived focal planes as there are waveguide / lens pairs available. Both the outcoupling optical elements of the waveguides and the focusing sides of the lenses may be static (i.e., not dynamic or electroactive). In some alternative embodiments, one or both may be dynamic using electroactive features.

[0038] In some embodiments, two or more of the waveguides 270, 280, 290, 300, 310 may have the same associated depth plane. For example, multiple waveguides 270, 280, 290, 300, 310 may be configured to output images set at the same depth plane, or multiple subsets of the waveguides 270, 280, 290, 300, 310 may be configured to output images set at the same depth planes, with one set per depth plane. This may provide the advantage of forming tiled images to provide an extended field of view at those depth planes.

[0039] Continuing with reference to FIG. 6, the outcoupling optical elements 570, 580, 590, 600, 610 may be configured to redirect light from its respective waveguide and output the light with an appropriate amount of divergence or collimation for a particular depth plane associated with the waveguide. As a result, waveguides with different associated depth planes may have different configurations of outcoupling optical elements 570, 580, 590, 600, 610 that output light with different amounts of divergence depending on the associated depth plane. In some embodiments, the light extraction optical elements 570, 580, 590, 600, 610 may be volume or surface features that may be configured to output light at specific angles. For example, the light extraction optical elements 570, 580, 590, 600, 610 may be volume holograms, surface holograms, and / or diffraction gratings. In some embodiments, the features 320, 330, 340, 350 may not be lenses. Rather, they may simply be spacers (e.g., cladding layers and / or structures for forming air gaps).

[0040] In some embodiments, the outcoupling optical elements 570, 580, 590, 600, 610 are diffractive features that form a diffraction pattern or "diffractive optical element" (also referred to herein as "DOE"). Preferably, the DOE has a sufficiently low diffraction efficiency such that only a portion of the light in the beam is deflected toward the eye 210 at each intersection of the DOE, while the remainder continues traveling through the waveguide via TIR. The light carrying the image information is thus split into several related exit beams that exit the waveguide at multiple locations, resulting in a very uniform pattern of exit emission toward the eye 210 for this particular collimated beam bouncing within the waveguide.

[0041] In some embodiments, one or more DOEs may be switchable between an "on" state in which they actively diffract and an "off" state in which they do not significantly diffract. For example, a switchable DOE may comprise a layer of polymer dispersed liquid crystal in which microdroplets comprise a diffractive pattern in a host medium, and the refractive index of the microdroplets may be switched to substantially match the refractive index of the host material (in which case the pattern does not significantly diffract incident light), or the microdroplets may be switched to a refractive index that does not match that of the host medium (in which case the pattern actively diffracts incident light).

[0042] In some embodiments, a camera assembly 630 (e.g., a digital camera, including visible and infrared light cameras) may be provided to capture images of the eye 210 and / or tissue surrounding the eye 210, for example, to detect user input and / or monitor the physiological state of the user. As used herein, a camera may be any image capture device. In some embodiments, the camera assembly 630 may include an image capture device and a light source that projects light (e.g., infrared light) onto the eye, which may then be reflected by the eye and detected by the image capture device. In some embodiments, the camera assembly 630 may be mounted on the frame 80 (FIG. 2) and may be in electrical communication with the processing modules 140 and / or 150, which may process image information from the camera assembly 630 as discussed herein and, for example, make various determinations regarding the physiological state of the user. It should be understood that information regarding the physiological state of the user may be used to determine the behavior or emotional state of the user. Examples of such information include the user's movements and / or the user's facial expressions. The user's behavior or emotional state may then be triangulated with the collected environmental and / or virtual content data to determine relationships between the behavior or emotional state, the physiological state, and the environmental or virtual content data. In some embodiments, one camera assembly 630 may be utilized for each eye to monitor each eye separately.

[0043] 7, an example of an output beam output by a waveguide is shown. Although one waveguide is shown, it should be understood that other waveguides in the waveguide assembly 260 (FIG. 6) may function similarly and that the waveguide assembly 260 includes multiple waveguides. Light 640 is launched into the waveguide 270 at the input surface 460 of the waveguide 270 and propagates within the waveguide 270 by TIR. At the point where the light 640 impinges on the DOE 570, a portion of the light exits the waveguide as an output beam 650. The output beam 650 is shown as approximately parallel, but may be redirected to propagate to the eye 210 at an angle (e.g., divergent output beam formation) as discussed herein and depending on the depth plane associated with the waveguide 270. It should be understood that a nearly collimated exit beam may refer to a waveguide with out-coupling optics that out-couples light to form an image that appears to be set at a depth plane at a large distance (e.g., optical infinity) from the eye 210. Other sets of waveguides or other out-coupling optics may output a more divergent exit beam pattern, which would require the eye 210 to accommodate to a closer distance and focus on the retina, and would be interpreted by the brain as light from a distance closer to the eye 210 than optical infinity.

[0044] In some embodiments, a full color image may be formed at each depth plane by overlaying an image on each of the primary colors, for example, three or more primary colors. FIG. 8 illustrates an example of a stacked waveguide assembly, where each depth plane includes an image formed using multiple different primary colors. The illustrated embodiment shows depth planes 240a-240f, but more or less depths are also contemplated. Each depth plane may have three or more primary color images associated with it, including a first image of a first color G, a second image of a second color R, and a third image of a third color B. The different depth planes are indicated in the diagram by different numbers for diopters (dpt) following the letters G, R, and B. Merely by way of example, the numbers following each of these letters indicate the diopters (1 / m), i.e., the inverse distance of the depth plane from the viewer, and each box in the diagram represents an individual primary color image. In some embodiments, the exact locations of the depth planes for the different primary colors may be varied to account for differences in the eye's focusing of light of different wavelengths. For example, different primary color images for a given depth plane may be placed on depth planes that correspond to different distances from the user. Such an arrangement may increase visual acuity and user comfort, and / or reduce chromatic aberration.

[0045] In some embodiments, the light of each primary color may be output by a single dedicated waveguide, such that each depth plane may have multiple waveguides associated with it. In such embodiments, each box in the figure containing the letter G, R, or B may be understood to represent an individual waveguide, and three waveguides may be provided per depth plane, with three primary color images provided per depth plane. The waveguides associated with each depth plane are shown adjacent to each other in this drawing for ease of illustration, but it should be understood that in a physical device, the waveguides may all be arranged in a stack with one waveguide per level. In some other embodiments, multiple primary colors may be output by the same waveguide, such that, for example, only a single waveguide may be provided per depth plane.

[0046] 8, in some embodiments, G is green, R is red, and B is blue. In some other embodiments, other colors associated with other wavelengths of light, including magenta and cyan, may be used in addition to or may replace one or more of the red, green, or blue colors. In some embodiments, features 320, 330, 340, and 350 may be active or passive optical filters configured to block or select light from the surrounding environment to the viewer's eye.

[0047] It should be understood that references throughout this disclosure to a given color of light are understood to encompass light of one or more wavelengths within the range of wavelengths of light that are perceived by a viewer as that given color. For example, red light may include one or more wavelengths of light that are within the range of about 620-780 nm, green light may include one or more wavelengths of light that are within the range of about 492-577 nm, and blue light may include one or more wavelengths of light that are within the range of about 435-493 nm.

[0048] In some embodiments, the light source 530 (FIG. 6) may be configured to emit light at one or more wavelengths outside the range of a viewer's visual perception, such as light at infrared and / or ultraviolet wavelengths. Additionally, the waveguide in-coupling, out-coupling, and other light redirecting structures of the display 250 may be configured to direct and emit this light from the display toward the user's eye 210, for example, for imaging and / or user stimulation applications.

[0049] 9A, in some embodiments, light impinging on a waveguide may need to be redirected to in-couple the light into the waveguide. An in-coupling optical element may be used to redirect and in-couple the light into its corresponding waveguide. FIG. 9A illustrates a cross-sectional side view of an example of a plurality or set 660 of stacked waveguides, each including an in-coupling optical element. Each of the waveguides may be configured to output light of one or more different wavelengths or one or more different wavelength ranges. The stack 660 may correspond to the stack 260 (FIG. 6), and the illustrated waveguides of the stack 660 may correspond to a portion of the plurality of waveguides 270, 280, 290, 300, 310, although it should be understood that light from one or more of the image input devices 360, 370, 380, 390, 400 is launched into the waveguide from a position that requires the light to be redirected for in-coupling.

[0050] The illustrated set 660 of stacked waveguides includes waveguides 670, 680, and 690. Each waveguide includes an associated incoupling optical element (which may also be referred to as the light input area on the waveguide), for example, incoupling optical element 700 is disposed on a major surface (e.g., the top major surface) of waveguide 670, incoupling optical element 710 is disposed on a major surface (e.g., the top major surface) of waveguide 680, and incoupling optical element 720 is disposed on a major surface (e.g., the top major surface) of waveguide 690. In some embodiments, one or more of the incoupling optical elements 700, 710, 720 may be disposed on a bottom major surface of an individual waveguide 670, 680, 690 (particularly, one or more of the incoupling optical elements are reflective polarizing optical elements). As shown, the incoupling optical elements 700, 710, 720 may be disposed on the upper major surface of the respective waveguide 670, 680, 690 (or on top of the next lower waveguide), and in particular, the incoupling optical elements are transmissive deflecting optical elements. In some embodiments, the incoupling optical elements 700, 710, 720 may be disposed within the body of the respective waveguide 670, 680, 690. In some embodiments, as discussed herein, the incoupling optical elements 700, 710, 720 are wavelength selective such that they selectively redirect one or more wavelengths of light while transmitting other wavelengths of light. Although illustrated on one side or corner of the respective waveguide 670, 680, 690, it should be understood that the incoupling optical elements 700, 710, 720 may be disposed within other areas of the respective waveguide 670, 680, 690 in some embodiments.

[0051] As shown, the in-coupling optical elements 700, 710, 720 may be laterally offset from one another. In some embodiments, each in-coupling optical element may be offset to receive light without that light passing through another in-coupling optical element. For example, each in-coupling optical element 700, 710, 720 may be configured to receive light from different image input devices 360, 370, 380, 390, and 400 as shown in FIG. 6 and may be separated (e.g., laterally spaced) from the other in-coupling optical elements 700, 710, 720 so as to not substantially receive light from others of the in-coupling optical elements 700, 710, 720.

[0052] Each waveguide also includes an associated optically dispersive element, for example, optically dispersive element 730 is disposed on a major surface (e.g., the top major surface) of waveguide 670, optically dispersive element 740 is disposed on a major surface (e.g., the top major surface) of waveguide 680, and optically dispersive element 750 is disposed on a major surface (e.g., the top major surface) of waveguide 690. In some other embodiments, optically dispersive elements 730, 740, 750 may be disposed on the bottom major surfaces of the associated waveguides 670, 680, 690, respectively. In some other embodiments, the optically dispersive elements 730, 740, 750 may be disposed on both the top and bottom major surfaces of the associated waveguides 670, 680, 690, respectively, or the optically dispersive elements 730, 740, 750 may be disposed on different ones of the top and bottom major surfaces in different associated waveguides 670, 680, 690, respectively.

[0053] The waveguides 670, 680, 690 may be spaced apart and separated, for example, by gas, liquid, and / or solid layers of material. For example, as shown, layer 760a may separate the waveguides 670 and 680, and layer 760b may separate the waveguides 680 and 690. In some embodiments, layers 760a and 760b are formed from a low refractive index material (i.e., a material having a lower refractive index than the material forming the immediate neighbors of the waveguides 670, 680, 690). Preferably, the refractive index of the material forming layers 760a, 760b is 0.05 or more or 0.10 or less compared to the refractive index of the material forming the waveguides 670, 680, 690. Advantageously, the lower refractive index layers 760a, 760b may act as cladding layers to promote total internal reflection (TIR) ​​of light through the waveguides 670, 680, 690 (e.g., TIR between the top and bottom major surfaces of each waveguide). In some embodiments, the layers 760a, 760b are formed from air. Although not shown, it should be understood that the top and bottom of the illustrated set of waveguides 660 may include immediate cladding layers.

[0054] Preferably, for ease of manufacturing and other considerations, the materials forming the waveguides 670, 680, 690 are similar or the same, and the materials forming the layers 760a, 760b are similar or the same. In some embodiments, the materials forming the waveguides 670, 680, 690 may differ between one or more of the waveguides, and / or the materials forming the layers 760a, 760b may differ while still maintaining the various refractive index relationships discussed above.

[0055] 9A, light rays 770, 780, 790 are incident on the set of waveguides 660. It should be understood that light rays 770, 780, 790 may be injected into the waveguides 670, 680, 690 by one or more image injection devices 360, 370, 380, 390, 400 (FIG. 6).

[0056] In some embodiments, the light beams 770, 780, 790 have different wavelengths or different wavelength ranges that may correspond to different properties, e.g., different colors. The light beams 770, 780, 790 may also be displaced laterally to different locations that correspond to the lateral locations of the incoupling optical elements 700, 710, 720. Each of the incoupling optical elements 700, 710, 720 deflects the incident light such that the light propagates through a respective one of the waveguides 670, 680, 690 by TIR.

[0057] For example, incoupling optical element 700 may be configured to deflect light ray 770 having a first wavelength or range of wavelengths. Similarly, transmitted light ray 780 impinges on and is deflected by incoupling optical element 710, which is configured to deflect light of a second wavelength or range of wavelengths. Similarly, light ray 790 is deflected by incoupling optical element 720, which is configured to selectively deflect light of a third wavelength or range of wavelengths.

[0058] 9A, the deflected light beams 770, 780, 790 are deflected to propagate through the corresponding waveguides 670, 680, 690. That is, the incoupling optical elements 700, 710, 720 of each waveguide deflect the light into its corresponding waveguide 670, 680, 690 and incoupling the light into the corresponding waveguide. The light beams 770, 780, 790 are deflected at an angle that causes the light to propagate through, and thus be guided within, the respective waveguides 670, 680, 690 by TIR. For example, the deflection of the light beams 770, 780, 790 may be caused by one or more reflective, diffractive, and / or holographic optical elements, such as holographic, diffractive, and / or reflective redirection features, reflectors, or mirrors. Deflection may occur in some cases, for example, by microstructures such as one or more gratings and / or holographic and / or diffractive features in diffractive optical elements configured to turn or redirect the light as guided within the optical waveguide. The light rays 770, 780, 790 propagate through the individual waveguides 670, 680, 690 by TIR induced therein until they impinge on the corresponding optically dispersive elements 730, 740, 750 of the waveguides.

[0059] 9B, a perspective view of an embodiment of the multiple stacked waveguides of FIG. 9A is illustrated. As previously described, the incoupling light beams 770, 780, 790 are deflected by the incoupling optical elements 700, 710, 720, respectively, and then propagate and are guided by TIR within the waveguides 670, 680, 690, respectively. The guided light beams 770, 780, 790 then impinge on the light dispersive elements 730, 740, 750, respectively. The light dispersive elements 730, 740, 750 may comprise one or more reflective, diffractive, and / or holographic optical elements, such as holographic, diffractive, and / or reflective redirecting features, reflectors, or mirrors. The deflection may occur in some cases due to microstructures, such as one or more gratings and / or diffractive features within the holographic and / or diffractive optical elements, configured to redirect or redirect the light, such that it may be guided, for example, using an optical waveguide. The light rays 770, 780, 790 propagate through the respective waveguides 670, 680, 690 in a manner where they are deflected, however, the light rays 770, 780, 790 are still guided within the waveguides due to the TIR guided therein until they impinge on the corresponding optically dispersive elements 730, 740, 750 of the waveguides. The optically dispersive elements 730, 740, 750 deflect the light rays 770, 780, 790 to propagate towards the outcoupling optical elements 800, 810, 820, respectively.

[0060] The out-coupling optical elements 800, 810, 820 are configured to direct light, e.g., light rays 770, 780, 790, guided in the waveguide out of the waveguide toward the viewer's eye. The out-coupling optical elements 800, 810, 820 may therefore be configured to deflect and redirect light, e.g., light rays 770, 780, 790, guided in the waveguide at a more perpendicular angle to the surface of the waveguide to reduce the effects of total internal reflection (TIR) ​​so that the light is not guided in the waveguide but instead exits therefrom. Furthermore, these out-coupling optical elements 800, 810, 820 may be configured to deflect and redirect this light, e.g., light rays 770, 780, 790, toward the viewer's eye. Thus, the outcoupling optical elements 800, 810, 820 may comprise one or more reflective, diffractive, and / or holographic optical elements, such as holographic, diffractive, and / or reflective redirecting features, reflectors, or mirrors. Deflection may occur in some cases by microstructures, such as one or more gratings and / or diffractive features in the holographic and / or diffractive optical elements, configured to redirect or redirect light, for example, as guided with a light guide. The optical elements 800, 810, 820 may be configured to reflect, deflect, and / or diffractive the light rays 770, 780, 790 to propagate out of the waveguide toward the user's eye.

[0061] In some embodiments, the light dispersing element 730, 740, 750 is an orthogonal pupil expander (OPE). In some embodiments, the OPE both deflects or disperses the light to the outcoupling optical element 800, 810, 820 and replicates the beam or beams to form a larger number of beams that propagate to the outcoupling optical element. As the beam travels along the OPE, a portion of the beam may be split off from the beam and travel in a direction orthogonal to the beam, i.e., toward the outcoupling optical element 800, 810, 820. The orthogonal splitting of the beam within the OPE may occur repeatedly along the path of the beam and through the OPE. For example, the OPE may include a grating with an increasing reflectivity along the beam path such that a series of substantially uniform beamlets are produced from a single beam. In some embodiments, the outcoupling optical element 800, 810, 820 is an exit pupil (EP) or exit pupil expander (EPE) that directs the light to the viewer's eye 210 (FIG. 7). The OPE may be configured to increase a dimension of the eyebox, e.g., along the x direction, and the EPE may increase the eyebox in an axis that intersects (e.g., is perpendicular to) the axis of the OPE, e.g., along the y direction.

[0062] Thus, referring to Figures 9A and 9B, in some embodiments, the set of waveguides 660 includes, for each primary color, a waveguide 670, 680, 690, an in-coupling optical element 700, 710, 720, an optically dispersive element (e.g., OPE) 730, 740, 750, and an out-coupling optical element (e.g., EPE) 800, 810, 820. The waveguides 670, 680, 690 may be stacked with an air gap and / or cladding layer between each one. The in-coupling optical element 700, 710, 720 redirects or deflects the incoming light into its respective waveguide (with different in-coupling optical elements receiving different wavelengths of light). The light then propagates at an angle that will result in TIR within the respective waveguide 670, 680, 690, in which the light is guided. In the illustrated embodiment, light ray 770 (e.g., blue light) is polarized by the first in-coupling optical element 700 in the manner described above, then continues to propagate within the waveguide in which it is guided, interacting with the optically dispersive element (e.g., OPE) 730 where it is replicated into multiple light rays that propagate to the out-coupling optical element (e.g., EPE) 800. Light rays 780 and 790 (e.g., green and red light, respectively) pass through the waveguide 670, where light ray 780 is incident on and deflected by the in-coupling optical element 710. Light ray 780 will then proceed, via TIR, to its optically dispersive element (e.g., OPE) 740 where it bounces back down the waveguide 680 and is replicated into multiple light rays that propagate to the out-coupling optical element (e.g., EPE) 810. Finally, the light ray 790 (e.g., red light) passes through the waveguide 690 and impinges on the in-coupling optical element 720 of the waveguide 690. The in-coupling optical element 720 deflects the light ray 790 such that it propagates by TIR to the optical dispersive element (e.g., OPE) 750 where it is replicated into multiple light rays that propagate by TIR to the out-coupling optical element (e.g., EPE) 820. The out-coupling optical element 820 then finally replicates further and out-couples the light ray 790 to a viewer who also receives the out-coupled light from the other waveguides 670, 680.

[0063] FIG. 9C illustrates a top-down plan view (or front view) of the multiple stacked waveguide embodiment of FIGS. 9A and 9B. As shown, the waveguides 670, 680, 690 may be vertically aligned (e.g., along the x and y directions) along with each waveguide's associated light dispersive element 730, 740, 750 and associated out-coupling optical elements 800, 810, 820. However, as discussed herein, the in-coupling optical elements 700, 710, 720 are not vertically aligned. Rather, the in-coupling optical elements are preferably non-overlapping (e.g., spaced apart laterally along the x direction, as seen in the top-down view of the front view in this embodiment). Offsets in other directions, such as the y direction, can also be employed. This non-overlapping spatial arrangement facilitates the injection of light into different waveguides from different sources, such as different light sources and / or displays, on a one-to-one basis, thereby allowing a specific light source to be uniquely coupled to a specific waveguide. In some embodiments, arrays including non-overlapping laterally spatially separated internal coupling optical elements may be referred to as shifted pupil systems, and the internal coupling optical elements in these arrays may correspond to sub-pupils.

[0064] In addition to coupling light out of the waveguide, the external coupling optical elements 800, 810, 820 may collimate or diverge the light as if it originated from an object at a far or closer distance, depth, or depth plane. Collimated light corresponds, for example, to light from an object that is far from the view. Increasingly divergent light corresponds to light from an object that is closer, for example, 5-10 feet or 1-3 feet in front of the viewer. The natural lens of the eye accommodates when viewing an object that is closer to the eye, and the brain may sense this accommodation, which then also serves as a depth cue. Similarly, by diverging the light by a certain amount, the eye will accommodate and perceive the object as being at a closer distance. Thus, the external coupling optical elements 800, 810, 820 may be configured to collimate or diverge the light as if it originated from a far or near distance, depth, or depth plane. To that end, the out-coupling optical elements 800, 810, 820 may include refractive power. For example, the out-coupling optical elements 800, 810, 820 may include holographic, diffractive, and / or reflective optical elements, which in addition to deflecting or redirecting light out of the waveguide, may further include a refractive power to collimate or diverge the light. The out-coupling optical elements 800, 810, 820 may alternatively or additionally include a refractive surface, which includes a refractive power to collimate or diverge the light. The out-coupling optical elements 800, 810, 820 may thus comprise a refractive surface that provides a refractive power in addition to, for example, a diffractive or holographic redirecting feature. Such a refractive surface may also be included in addition to the out-coupling optical elements 800, 810, 820, for example, on top of the out-coupling optical elements 800, 810, 820. In some embodiments, for example, optical elements, such as diffractive optical elements, holographic optical elements, refractive lens surfaces, or other structures, may be positioned relative to the outcoupling optical elements 800, 810, 820 to provide optical power that results in collimation or divergence of light.A layer with refractive power, such as a layer with a refractive surface, or a layer with diffractive and / or holographic features, may, for example, be disposed relative to the outcoupling optical elements 800, 810, 820 and additionally provide refractive power. A combination of contributions from both the outcoupling optical elements 800, 810, 820 having refractive power and an additional layer with refractive power, such as a layer with a refractive surface, or a layer with diffractive and / or holographic features, is also possible.

[0065] Exemplary 3D Content Rendering Systems and Methods In various implementations, the augmented reality systems and methods described herein can be used to render virtual content, such as virtual objects, that appear to interact with real objects in the world around the wearer. In some embodiments, a depth sensor may be used to map the world around the wearer and / or the wearer's body parts, and the augmented reality system can render 3D virtual content, such as objects or graphics, onto real objects detected in the world. In one example, the virtual content can be a virtual watch rendered on the wearer's wrist. Thus, while the wearer of the head-mounted augmented reality device is not wearing a real watch, the virtual watch displayed to the wearer through the display of the device can appear to be located on the wearer's wrist. In another example, the virtual content can be a graphic design for display on a real object, such as a logo or advertising content for display on the side of a coffee cup.

[0066] The location of the real object associated with the virtual content can be tracked by a depth sensor or the like. The virtual content can be displayed at a location determined based on the location of the real object. For example, as the wearer moves the wrist associated with the virtual watch, the device can change the location of the virtual watch as it is displayed to the wearer so that the watch continues to appear on the wearer's wrist. However, existing depth sensors may not be able to detect the orientation of the real object associated with the virtual content. For example, if the wearer's wrist or coffee cup described above rotates, the information from the depth sensor may be insufficient to enable the system to distinguish between different symmetrical or near-symmetrical orientations of the real object. Thus, while a depth sensor may detect the location of a real object, the systems described herein may use secondary tracking of features of the real object (sometimes also referred to herein as landmarks or fiducial features) to identify more precise location and / or orientation information that the depth sensor cannot detect. Various systems and methods described herein may enable an augmented reality display system to track the location and orientation of an object based on the light reflectance and / or scattering properties of visible or invisible markers at or near the surface of the object. In some exemplary embodiments, the augmented reality display system may use a depth sensor to track the position of the object, identify features on the surface of the object, and determine the orientation of the object based on the location of the features relative to the object. The features (sometimes also referred to herein as fiducial features or fiducials) may be pre-existing features of the object such that the orientation of the object may be tracked without separately applying additional markers for the purpose of orientation tracking. As will be described in more detail, the features or fiducials may be detected using visible or invisible light, such as in the infrared or ultraviolet range. The fiducials or features may be background features, such as a birthmark on the wrist or a seam in a coffee cup, or invisible features, such as one or more veins on the wrist, arm, or hand.

[0067] Reference is now made to FIG. 10, which illustrates a schematic diagram of various components of an exemplary augmented reality display system 2010 configured to track the location and orientation of a real object as described herein. In some embodiments, the augmented reality display system may be a mixed reality display system. As shown, the augmented reality display system 2010 includes a frame 64 at least partially surrounding a left waveguide stack 2005 and a right waveguide stack 2006 configured to deliver augmented reality content to a left eye 2001 and a right eye 2002 of a wearer of the augmented reality display system 2010. The system further includes a depth sensor 28, a light source 26, and a light detector 24. The tracking system 22 may include a processing module 70, which may control and / or analyze data received from the depth sensor 28, the light detector 24, and / or the light source 26. The depth sensor 28, the light detector 24, and / or the light source 26 may communicate with the processing module 70 through data links 76, 78.

[0068] The depth sensor 28 can be configured to detect the shape and location of various objects in the world around the wearer. For example, objects detected by the depth sensor 28 can include walls, furniture, and other items in a room surrounding the wearer, other people or animals in the wearer's vicinity, outdoor objects such as trees, shrubs, cars, buildings, and the like, and / or parts of the wearer's body such as arms, hands, legs, and feet. In various embodiments, the depth sensor can be effective in mapping objects at a distance range of 0.5 meters to 4 meters, 1 meter to 3 meters, up to 5 meters, or any other range from the wearer. The depth sensor can be an optical depth sensor configured to determine depth using infrared light, visible light, or the like. In various embodiments, the depth sensor may include one or more of a laser source, a laser range finder, a camera, an ultrasonic range finder, or other distance sensing, imaging, and / or mapping device.

[0069] The photodetectors 24 can be configured to detect one or more of infrared light, visible light, ultraviolet light, or other ranges of electromagnetic radiation. Similarly, the light sources 26 may be configured to emit infrared light, visible light, ultraviolet light, or other ranges of electromagnetic radiation. In some embodiments, at least a portion of the spectrum emitted by the light sources 26 will be detectable by the photodetectors 24. In some designs, the light sources 26 can be mounted on a gimbal or other movable mount such that the direction of the emitted radiation can be controlled independently from the orientation of the augmented reality display device 2010. The photodetectors 24 can be imaging devices, such as cameras, configured to acquire images of light within at least a portion of the wearer's field of view. In various embodiments, each photodetector 24 can be a camera and may comprise a two-dimensional array of light sensors. In some exemplary embodiments, the light sources 26 are configured to emit infrared light within a defined wavelength range, and the photodetectors 24 comprise infrared sensors or infrared photodetectors configured to acquire infrared images using infrared light reflected by objects within the field of view of the photodetectors 24.

[0070] In some cases, features that are not noticeable in visible light create distinguishable features when illuminated with invisible light, such as infrared or ultraviolet light. For example, veins, which may be unresolvable to the eye, may become clearly resolvable by an infrared camera in response to infrared illumination. Such veins may be used as fiducials to identify the object and track its movement, its translation, and / or changes in orientation. Thus, illuminating an object with light, such as invisible light, may cause features that are otherwise invisible to be detected by a camera or imaging sensor. The movement of these features, which may be referred to as fiducials (or difference signatures, as described more fully below), may allow the movement of the object to be tracked, such that, for example, placement of virtual content relative to the moving object may be properly placed. Although veins are used as an example, other features may also be observable with illumination, such as infrared illumination, using infrared detectors. For example, other features of the skin may also reflect or absorb IR light (or UV light) to create features, markers, or fiducials that may be tracked using a camera sensitive to a suitable wavelength (e.g., an IR sensor) to track the movement of the object, including changes in the rotation or orientation of the object. Once the object's movements and orientation changes are known, virtual content can be accurately positioned and oriented. Such virtual content that is designed to follow the object or have a fixed location and / or orientation relative to the object can be rendered appropriately. Similarly, appropriate viewpoints for the virtual content can be provided. Although infrared and ultraviolet light are discussed in the examples above, other wavelengths of light or electromagnetic radiation, both visible and invisible, can also be used.

[0071] In some cases, the illumination may comprise a pattern, such as a grid or array. Additionally, an image of the pattern projected onto the surface may be compared by the processing module 70 to the emitted pattern of light to determine the difference between the emitted and reflected light. Similarly, the processing module 70 may be configured to identify locally unique differences in the image. Locally unique differences may be caused by portions of a real object having a different reflectance than the surrounding area. For example, birthmarks, moles, veins, scar tissue, or other structures on an arm or hand may have a different reflectance within the wavelength range being imaged (e.g., infrared or UV) that differs from the reflectance of the surrounding tissue. Thus, if an area of ​​scar tissue is present within the illuminated and imaged area, the light difference between the emitted and reflected radiation distributions may include an abnormal region in the shape of the scar tissue area. Such features, referred to herein as difference signatures, can be used to track the object so that virtual content can be properly located and oriented relative to the object.

[0072] With reference to both Figures 10 and 11, an example method 1100 of tracking a location and / or orientation of a 3D object using detected features will now be described. The method 1100 may be implemented by any of the systems described herein, such as the wearable augmented reality display systems 60, 2010 depicted in Figures 2 and 10. The method 1100 begins at block 1110, where virtual content is received. In one embodiment, the virtual content can be a 3D rendering of a wristwatch, which can serve as a virtual watch visible to a wearer of the augmented reality display system 2010. The system 2010 also receives the location of the virtual content relative to the detected real object. For example, the system 2010 may detect the wearer's wrist using the depth sensor 28, either automatically or based on an indication by the wearer. The location relative to the virtual watch may be determined automatically or may be indicated by the wearer, such as by gesture or using any suitable input device. For example, the wearer may select a location for the virtual watch such that the virtual watch appears to be placed around the wearer's wrist, like a real-world wrist watch. In another example, the virtual content may be a virtual name tag or item identifier, an advertising graphic for display on a real object such as a coffee cup, or any other type of virtual content that is intended to behave as if it were attached to a real object. Once the desired location of the virtual content has been determined relative to the real object, a relative location may be selected, aligned, or otherwise finalized. After the virtual content and its location relative to the real object have been received, method 1100 continues to block 1120.

[0073] In block 1120, the system 2010 emits a radiation pattern and determines the difference between the image of the pattern projected onto the object. The difference may depend on and be indicative of structural features of the real object. The difference may be indicative of variations in absorptivity, reflectivity, and / or scattering, for example, due to structural variations in the object. The difference may be used as a reference, difference signature, or marker to track changes in movement and / or orientation. The radiation pattern is emitted by the light source 26 and may be a light pattern such as a textured light field, a grid, or a series of dots, crosses, circles, (e.g., concentric circles or contours), or other patterns. Although patterns such as grids are discussed above, the illumination may also comprise substantially uniform illumination or spots of any shape (e.g., circles, squares, etc.) and still a difference signature or marker may be obtained. The emitted radiation pattern may comprise visible or invisible light, such as infrared light, ultraviolet light, or any other suitable wavelength or range of wavelengths. In some embodiments, non-visible wavelength ranges, such as infrared or ultraviolet, may be desirable to avoid distracting the wearer or others by projecting a visible light pattern or visible light. The direction of the radiation pattern may be selected such that at least a portion of the radiation pattern is incident on the surface of the real object. For example, in some configurations, the light source is movable, such as via a gimbal mount or other rotating and / or tiltable stage. In some embodiments, the radiation may be projected onto a location in close proximity to the received location of the virtual object. In an exemplary implementation of a virtual watch, the radiation may be projected onto the back of the wearer's hand or the wearer's forearm adjacent to the location of the virtual watch. In other embodiments, the radiation may be projected onto a location spaced apart from the location of the virtual object.

[0074] After the radiation pattern is emitted, a portion of the emitted radiation may be reflected by the real object to the augmented reality display system 2010. A portion of the emitted radiation may be reflected by an outer surface or an internal structure below the surface of the object. For example, if the radiation pattern is an infrared light pattern directed at a user's arm or hand, a portion of the infrared light may be reflected by the outer skin surface, an internal region of the skin, and / or veins or other structures below the skin. The reflected portion of the radiation pattern may be detected at the photodetector 24. For example, the light source 26 may be an infrared source that emits an infrared radiation pattern, and the photodetector 24 may be an infrared camera configured to capture an image in the infrared spectrum. Thus, when a portion of the emitted radiation pattern is reflected to the display system 2010, the photodetector 24 may capture an image of the reflected light pattern.

[0075] To determine a light difference signature, the image of the reflected light pattern can be compared to the distribution of the emitted radiation pattern. The determination of the light difference signature can occur in the processing module 70 or any other local or remote processing circuitry associated with the augmented reality display system 2010. The processing module 70 can look for unique differences between the emitted and reflected light patterns, which can be used as landmarks, markers, or references. If a unique difference is found between the emitted and reflected light patterns, the difference can be stored and the light difference signature or marker can also be recorded. In some cases, the unique difference can be caused by a part of a real object, such as a birthmark, mole, vein, scar tissue, or other structure on an arm or hand, having a different reflectance than the surrounding area. For example, if a region of scar tissue is present within the illuminated and imaged area, the light difference between the emitted and reflected radiation distributions may include an abnormal region in the shape of the scar tissue region, which may serve as a landmark or difference signature (because different types of biological tissue, such as skin, fat, oxygenated blood, deoxygenated blood, etc., may have different infrared absorption and scattering properties, the radiation pattern may include multiple wavelengths of light if a unique difference cannot be detected at the first wavelength). If a detectable and / or locally unique sub-region of light difference is found between the emitted and reflected light patterns, this difference may be stored as a light difference signature. If no unique difference that may be used as a landmark or reference is found after comparing the emitted and reflected light patterns, block 1120 may be repeated by emitting the radiation pattern at a different location on the real object, for example, adjacent to a different portion of the virtual object location and / or slightly further away from the virtual object location. If a unique difference that can be used as a landmark is identified and stored as a light difference signature or marker, the method 1100 continues to block 1130 .

[0076] At block 1130, a location of the virtual content is determined relative to the light difference signature, landmark, or "difference marker." The location of the light difference signature or landmark or difference marker can serve as a reference point for rendering the virtual content. A displacement can then be determined relative to the reference point with respect to the virtual object. For example, the displacement can include coordinates in one or more dimensions. In some embodiments, the displacement can be a location in a two-dimensional or three-dimensional coordinate system with an origin as a reference point. Thus, if the same light difference signature or marker or landmark is detected again, the virtual content can be rendered in the same location relative to the light difference signature, marker, or landmark.

[0077] In some implementations, the light difference signature, marker, or landmark may be further associated with a physical reference point in the real world detectable by the depth sensor 28. The physical reference point may be a feature of a real object, such as a finger or wrist bone in the virtual watch embodiment described herein. The location of the light difference signature, marker, or landmark, as well as the location of the virtual object relative to the light difference signature, marker, or landmark, relative to the physical reference point may include coordinates in one or more dimensions. The displacement between the virtual object and the light difference marker or landmark and between the physical reference point and the light difference marker or landmark may be recorded in the same or different reference frames or coordinate systems.

[0078] After the locations of the virtual content and the physical reference points have been determined relative to the light difference markers or landmarks, the system 2010 may intermittently or continuously monitor the locations of the physical reference points using the depth sensor 28. In some embodiments, the depth sensor 28 may not require as much power and / or processing capacity as the light detector 24 and light source 26 to continuously monitor the locations of the real objects and / or the physical reference points. Thus, while the depth sensor 28 may continuously monitor the locations of the physical reference points, the emission and detection of radiation or radiation patterns by the light source 26 and light detector 24 may be utilized less frequently, such as when a change is detected in the location of the physical reference points, when a frame of virtual content needs to be refreshed, or at any other regular or irregular interval. When the location of the virtual content rendering should be refreshed, the method 1100 continues to block 1140. In block 1140, radiation or a radiation pattern is again emitted. The radiation emitted in block 1140 can be the same distribution (e.g., uniform distribution, spots, patterns, textures, or the like) as the radiation emitted in block 1120. The radiation direction of the radiation pattern can be determined based on the location of a physical reference point as tracked by the depth sensor 28 such that the emitted radiation pattern falls, at least in part, on an area of ​​the real object where the light difference signature, marker, or landmark is expected to be found. The radiation direction can be selected by pivoting or otherwise moving the light source 24 on a gimbal or other movable mounting platform. For example, in an embodiment of the wearer's arm, the emitted radiation pattern can be directed to the location of a birthmark, vein, or other feature associated with the light difference signature, marker, or landmark based on a calculated displacement from the physical reference point. The radiation or radiation pattern can be emitted by the light source 24 in the same manner as described above with reference to block 1120. After the radiation or radiation pattern is emitted, the method 1100 continues to block 1150 .

[0079] In block 1150, the system 2010 obtains a reflected radiation distribution or pattern and locates a difference signature, marker, or landmark within the reflected radiation distribution or pattern. The reflected radiation or pattern can be detected and / or imaged by the photodetector 26, configured to detect one or more wavelengths of light emitted by the light source 24. A difference can then be determined and / or calculated between the emitted radiation pattern and the reflected radiation pattern. The stored light difference signature or marker or landmark can be compared to the difference between the emitted and reflected radiation distribution or pattern to verify the presence and determine the location of the light difference signature, marker, or landmark within the newly reflected radiation distribution. The location of the light difference signature, marker, or landmark can then be recorded to serve as a reference point for rendering of the virtual content when the virtual content is refreshed. After the light difference marker is located within the reflected radiation distribution or difference, the method 1100 continues to block 1160.

[0080] In block 1160, the virtual content is rendered relative to the location of the light difference signature, marker, or landmark. The location for rendering the virtual content can be determined based on the displacement between the light difference signature, marker, or landmark and the virtual content calculated in block 1130. By using the same displacement previously calculated, the augmented reality display system 2010 can achieve the advantage of displaying virtual content that appears to move with the associated real object. For example, by repeatedly rendering a virtual watch at the same displacement relative to a light difference signature, marker, or landmark caused by a birthmark or a group of veins on the wearer's hand, the face of the virtual watch can appear to remain adjacent to the top side of the wearer's wrist even if the wearer rotates the wrist or otherwise alters the orientation of the wrist in a manner that cannot be reliably detected by the depth sensor 28 alone. After the virtual content has been rendered for the light differential signatures, markers, or landmarks, method 1100 may return to block 1140, where blocks 1140-1160 may be repeated indefinitely at regular or irregular intervals, as necessary, whenever the virtual content frame is to be refreshed. For example, method 1100 may return to block 1140 any time a change in the location of the physical reference point is detected, or at regular intervals, such as every second, 5 times / second, 10 times / second, 50 times / second, 100 times / second, or any other suitable interval. In some embodiments, light source 24 may be configured to continuously project radiated light, such as infrared light, rather than transmitting a discrete pulse of light each time the differential marker is to be relocated. As discussed above, the systems, devices, methods, and processes discussed with respect to illuminating a pattern of light also apply to uniform illumination or the projection of spots of any shape, such as circular spots. Additionally, while the discussion above referenced the identification and use of a marker or landmark, multiple markers or landmarks may also be identified and used to provide tracking and placement of virtual image content.

[0081] It is contemplated that the innovative aspects may be implemented in or associated with a variety of applications and thus include a wide range of variations. For example, variations in the shape, number, and / or optical power of the EPEs are contemplated. The structures, devices, and methods described herein may find use in displays, such as wearable displays (e.g., head-mounted displays), that may be used for augmented and / or virtual reality, among others. More generally, the described embodiments may be implemented within any device, apparatus, or system that may be configured to display images, whether under motion (such as video) or stationary (such as still images), and whether text, graphics, or photographs. However, the described embodiments may be used in a variety of devices, including, but not limited to, mobile phones, multimedia Internet-enabled cellular phones, mobile television receivers, wireless devices, smartphones, Bluetooth devices, personal digital assistants (PDAs), wireless email receivers, handheld or portable computers, netbooks, notebooks, smartbooks, tablets, printers, copiers, scanners, fax devices, Global Positioning System (GPS) receivers / navigators, cameras, digital media players (such as MP3 players), camcorders, game consoles, watches, clocks, calculators, television monitors, flat panel displays, electronic readout devices, and the like. It is contemplated that the electronic device may be contained within or associated with a variety of electronic devices, such as electronic devices (e.g., electronic readers), computer monitors, automotive displays (including odometer and speedometer displays, etc.), cockpit controls and / or displays, camera view displays (such as a rear camera display in a vehicle), electronic photography, electronic billboards or signs, projectors, architectural structures, microwave ovens, refrigerators, stereo systems, cassette recorders or players, DVD players, CD players, VCRs, radios, portable memory chips, washing machines, dryers, washer-dryers, parking meters, head mounted displays, and various imaging systems.Accordingly, the present teachings are not limited to only the embodiments depicted in the figures, but instead are intended to have broad applicability that will be readily apparent to those skilled in the art.

[0082] Various modifications of the embodiments described in this disclosure may be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments without departing from the spirit or scope of the present disclosure. Thus, the claims are not intended to be limited to the embodiments shown herein, but should be accorded the widest scope consistent with the present disclosure, principles, and novel features disclosed herein. The word "exemplary" is used exclusively herein to mean "serving as an example, instance, or illustration." Any embodiment described herein as "exemplary" is not necessarily to be construed as being preferred or advantageous over other embodiments. In addition, those skilled in the art will readily appreciate that the terms "upper" and "lower," "above" and "below," and the like, are sometimes used for ease of illustrating the figures, and indicate relative positions that correspond to the orientation of the figures on a properly oriented page, and may not reflect the proper orientation of the structures described herein as those structures are implemented.

[0083] Certain features described herein in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable subcombination. Moreover, although features may be described above as acting in a combination and may even initially be claimed as such, one or more features from the claimed combination may in some cases be deviated from the combination and the claimed combination may be directed to a subcombination or a variation of the subcombination.

[0084] Similarly, although operations are depicted in the figures in a particular order, this should not be understood as requiring such operations to be performed in the particular order shown or in a sequential order, or that all of the depicted operations be performed, to achieve desirable results. Additionally, the figures may diagrammatically depict one or more exemplary processes in the form of a flow chart. However, other operations not depicted may also be incorporated within the diagrammatically depicted exemplary process. For example, one or more additional operations may be performed before, after, simultaneously with, or during any of the depicted operations. In some circumstances, multitasking and parallel processing may be advantageous. Furthermore, the separation of various system components in the embodiments described above should not be understood as requiring such separation in all embodiments, and it should be understood that the described program components and systems may generally be integrated together in a single software product or packaged into multiple software products. Additionally, other embodiments are within the scope of the following claims. In some cases, the actions recited in the claims may be performed in a different order and still achieve desirable results.

[0085] Various exemplary embodiments of the present invention are described herein. Reference is made to these examples in a non-limiting sense. They are provided to illustrate the more broadly applicable aspects of the present invention. Various modifications may be made to the described invention, and equivalents may be substituted without departing from the true spirit and scope of the invention. In addition, many modifications may be made to adapt a particular situation, material, composition, process, act or step of a process to the objective, spirit or scope of the present invention. Furthermore, as will be understood by those skilled in the art, each of the individual variations described and illustrated herein has discrete components and features that may be easily separated from or combined with the 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.

[0086] The present invention includes methods that may be performed using the 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" merely requires the end user to obtain, access, access, position, configure, activate, power on, or otherwise act to provide the requisite device in the method. The methods described herein may be carried out in any order of the recited events that is logically possible, and in the recited order of events.

[0087] Exemplary aspects of the invention have been described above, along with details regarding material selection and manufacturing. As to other details of the invention, these can be understood in conjunction with the above-referenced patents and publications, and generally understood or understood by those skilled in the art. The same may be true with respect to method-based aspects of the invention in terms of additional acts as generally or theoretically adopted.

[0088] 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 those described or indicated as being considered with respect to each variation of the present invention. Various modifications may be made to the invention described, and equivalents may be substituted (whether described herein or not included for some brevity) without departing from the true spirit and scope of the invention. In addition, when a range of values ​​is provided, it is understood that all intervening values ​​between the upper and lower limits of that range, and any other stated or intervening values ​​within that stated range, are encompassed within the present invention.

[0089] It is also contemplated that any optional feature of the inventive variations described herein may be described and claimed independently or in combination with any one or more of the features described herein. Reference to a singular item includes the possibility that there are multiple identical items. More specifically, as used herein and in the claims associated therewith, the singular forms "a," "an," "said," and "the" include multiple referents unless specifically stated otherwise. In other words, the use of articles allows for "at least one" of the subject item in the above description and in the claims associated with this disclosure. Furthermore, it is noted that such claims may be drafted to exclude any optional element. Thus, this statement is intended to serve as a predicate for the use of such exclusive terms, such as "only," "only," and the like, in connection with the description of claim elements, or the use of "negative" limitations.

[0090] Without using such exclusive terms, the term "comprising" in the claims associated with this disclosure is intended to permit the inclusion of any additional elements, regardless of whether a given number of elements are recited in such claims or whether the addition of features may be considered to change the nature of the elements recited in such claims. Unless specifically defined herein, all technical and scientific terms used in this specification are to be given the broadest possible commonly understood meaning while maintaining the validity of the claims.

[0091] The scope of the present invention is not intended to be limited to the examples provided and / or this specification, but rather is intended to be limited only by the scope of the claims associated with this disclosure. The present specification also provides, for example, the following items: (Item 1) 1. An augmented reality display system configured to align 3D content with real objects, the system comprising: a frame configured to mount on a wearer; an augmented reality display attached to the frame and configured to direct images to an eye of the wearer; a light source configured to illuminate at least a portion of the object by emitting invisible light; a light sensor configured to image the portion of the object illuminated by the light source using the invisible light; a processing circuit configured to determine information regarding a location of the object, an orientation of the object, or both based on one or more characteristics of features in the image formed using the reflected portion of the invisible light; and A system comprising: (Item 2) 2. The augmented reality display system of claim 1, wherein features in the image formed using the reflected portion of the invisible light are invisible to the eye. (Item 3) 3. The augmented reality display system of any of items 1-2, wherein the invisible light comprises infrared light. (Item 4) 4. The augmented reality display system of any of items 1-3, wherein the invisible light emitted by the light source comprises a beam that forms a spot on the portion of the object. (Item 5) 4. The augmented reality display system of any of items 1-3, wherein the invisible light emitted by the light source comprises a light pattern. (Item 6) 6. The augmented reality display system of any of claims 1-5, wherein the characteristics include a location of the feature. (Item 7) 7. The augmented reality display system of any of claims 1-6, wherein the characteristic comprises a shape of the feature. (Item 8) 8. The augmented reality display system of any of claims 1-7, wherein the characteristic comprises an orientation of the feature. (Item 9) 9. The augmented reality display system of any of items 1-8, further comprising a depth sensor configured to detect the location of real objects within the world. (Item 10) 10. The augmented reality display system of any of items 1-9, wherein the processing circuit is configured to determine a difference between a distribution of the emitted invisible light and a distribution of a reflected portion of the invisible light. (Item 11) Item 11. The augmented reality display system of item 10, wherein the processing circuitry is configured to identify a difference signature based on the determined difference. (Item 12) Item 12. The augmented reality display system of item 11, wherein the processing circuitry is configured to determine an orientation of the real object based on a location of the real object and a location of the difference signature. (Item 13) Item 12. The augmented reality display system of item 11, wherein the processing circuitry is configured to determine a location of the real object based, at least in part, on a location of the difference signature. (Item 14) 14. The augmented reality display system of any of items 1-13, further comprising an eyepiece disposed on the frame, at least a portion of the eyepiece being transparent and positioned in a location in front of the wearer's eye when the wearer wears the display system so as to transmit light from an environment in front of the wearer to the wearer's eye and provide a view of the environment in front of the wearer. (Item 15) 1. An augmented reality display system, comprising: a frame configured to mount on a wearer; an augmented reality display attached to the frame and configured to direct images to an eye of the wearer; a depth sensor configured to map a surface of a real object within the wearer's field of view; a light source configured to project light at least at a first wavelength incident on a surface of the real object; a light detector configured to form an image using a portion of the light reflected by a surface of the real object; a processing circuit configured to determine a light difference marker based at least in part on the reflected portion of the light pattern and to render a virtual object at a fixed displacement relative to the light difference marker; An augmented reality display system comprising: (Item 16) Rendering the virtual object at a fixed displacement relative to the light difference markers includes: receiving an initial location for rendering the virtual object relative to the real object at an initial time; determining the fixed displacement based on a distance between the initial location and the optical difference marker; detecting a subsequent location of the optical difference marker at a time subsequent to the initial time; rendering the virtual object at the fixed displacement relative to the detected subsequent location of the light difference marker; Item 16. The augmented reality display system of item 15, comprising: (Item 17) Item 17. The augmented reality display system of item 15 or 16, further comprising an eyepiece disposed on the frame, at least a portion of the eyepiece being transparent and positioned in a location in front of the wearer's eye when the wearer wears the display system so as to transmit light from an environment in front of the wearer to the wearer's eye and provide a view of the environment in front of the wearer. (Item 18) 1. An augmented reality display system configured to align 3D content with real objects, the system comprising: a frame configured to mount on a wearer; an augmented reality display attached to the frame and configured to direct images to an eye of the wearer; a depth sensor configured to map a surface of a real object within the wearer's field of view; a light source configured to emit light and thereby illuminate at least a portion of the object; a light sensor configured to image the portion of the object illuminated by the light source using the emitted light; a processing circuit configured to determine information regarding a location of the real object, an orientation of the real object, or both based on one or more characteristics of features in the image of the object; A system comprising: (Item 19) Item 19. The augmented reality display system of item 18, wherein the light emitted by the light source comprises a beam that forms a spot on the portion of the object. (Item 20) Item 19. The augmented reality display system of item 18, wherein the light emitted by the light source comprises a light pattern. (Item 21) 21. The augmented reality display system of any of items 18-20, wherein the characteristics include a location of the feature. (Item 22) 22. The augmented reality display system of any of claims 18-21, wherein the characteristic comprises a shape of the feature. (Item 23) 23. The augmented reality display system of any of items 18-22, wherein the characteristic comprises an orientation of the feature. (Item 24) 24. The augmented reality display system of any of items 18-23, wherein the processing circuit is configured to determine a difference between the distribution of the emitted light and the distribution of the emitted light reflected from the object. (Item 25) 25. The augmented reality display system of claim 24, wherein the processing circuitry is configured to identify a light difference marker based on the determined difference. (Item 26) 26. The augmented reality display system of claim 25, wherein the processing circuitry is configured to determine an orientation of the real object based, at least in part, on the location of the light difference marker. (Item 27) 27. The augmented reality display system of claim 25 or 26, wherein the processing circuitry is configured to determine a location of the real object based, at least in part, on a location of the light difference marker. (Item 28) 28. The augmented reality display system of any of items 18-27, wherein the depth sensor comprises a laser or an ultrasonic range finder. (Item 29) 29. The augmented reality display system of any of items 18-28, wherein the depth sensor comprises a camera. (Item 30) 30. The augmented reality display system of any of items 18-29, further comprising an eyepiece disposed on the frame, at least a portion of the eyepiece being transparent and positioned in a location in front of the wearer's eye when the wearer wears the display system so as to transmit light from an environment in front of the wearer to the wearer's eye and provide a view of the environment in front of the wearer. (Item 31) 2. The augmented reality display system of claim 1, wherein the display is configured to render image content as if different image content were located at different depths. (Item 32) 30. The augmented reality display system of claim 28, wherein the display includes a multi-refractive power optical element having different refractive powers to provide the different depths.

Claims

1. 1. An augmented reality display system configured to align 3D content with real objects, the system comprising: a frame configured to mount on a wearer; an augmented reality display attached to the frame, the augmented reality display configured to direct light representing visual information to an eye of the wearer; a light source configured to illuminate at least a portion of the real object by emitting invisible light; a light sensor configured to image the portion of the real object illuminated by the light source using the invisible light; a depth sensor configured to detect a location of the real object; Processing circuit and Equipped with The processing circuitry includes: monitoring a location of the real object using the depth sensor periodically at a first frequency; periodically at a second frequency, lower than the first frequency, monitoring an orientation of the real object based on one or more characteristics of a feature in an image formed using the reflected portion of the invisible light; 16. An augmented reality display system configured to:

2. The augmented reality display system of claim 1 , wherein the processing circuitry is further configured to render augmented reality content onto a view of the real object through the augmented reality display.

3. The augmented reality display of claim 2 , wherein the processing circuitry is configured to orient the rendered augmented reality content based at least in part on the monitored orientation of the real object.

4. The augmented reality display system of claim 1 , wherein the processing circuitry is further configured to determine a difference between a distribution of the emitted invisible light and a distribution of a reflected portion of the invisible light.

5. The augmented reality display system of claim 4 , wherein the processing circuitry is further configured to identify a difference signature based on the determined difference.

6. The augmented reality display system of claim 5 , wherein the processing circuitry is further configured to detect the feature in the image based at least in part on the difference signature.

7. 7. The augmented reality display system of claim 6, wherein the processing circuitry is further configured to select and store the features to be used as markers for rendering augmented reality content onto a view of the real object through the augmented reality display.

8. The augmented reality display system of claim 7 , wherein the real object comprises the skin of the wearer or of a person other than the wearer.

9. The augmented reality display system of claim 8 , wherein the features include existing surface features of the skin.

10. 2. The augmented reality display system of claim 1, wherein the augmented reality display is configured to transmit light from an environment in front of the wearer to the wearer's eye while the augmented reality display directs an image to the wearer's eye to provide a view of the environment in front of the wearer.

11. 1. A method for aligning 3D content with real objects, the method comprising, under control of a processing circuit, - illuminating at least a portion of the real object by causing a light source of an augmented reality display system to emit invisible light; imaging the portion of the real object illuminated by the light source using a light sensor of the augmented reality display system; monitoring a location of the real object periodically at a first frequency using a depth sensor of the augmented reality display system; periodically at a second frequency, lower than the first frequency, monitoring an orientation of the real object based on one or more characteristics of a feature in an image formed using the reflected portion of the invisible light; rendering augmented reality content to a wearer of the augmented reality display system on a view of the real object through an augmented reality display of the augmented reality display system; The method of claim 1, further comprising:

12. The method of claim 11 , wherein the rendered augmented reality content is oriented based at least in part on the monitored orientation of the real object.

13. The method of claim 11 , wherein a virtual location of the rendered augmented reality content is determined based at least in part on the monitored location of the real object.

14. The method of claim 11 , further comprising determining a difference between a distribution of the emitted invisible light and a distribution of a reflected portion of the invisible light.

15. The method of claim 14 , further comprising identifying a difference signature based on the determined differences.

16. The method of claim 15 , further comprising detecting the feature in the image based at least in part on the difference signature.

17. The method of claim 16 , further comprising selecting and storing the features to be used as markers for rendering the augmented reality content on a view of the real object.

18. The method of claim 17 , wherein the real object comprises the skin of the wearer or of a person other than the wearer.

19. The method of claim 18 , wherein the features include existing surface features of the skin.

20. 20. The method of claim 19, wherein the feature comprises a birthmark, a mole, or scar tissue.

Images