Waveguide-based lighting for head-mounted display systems

Abstract

To provide a head-mounted display system configured to project light to an eye of a user wearing the head-mounted display system to display content in a visual field of the user.SOLUTION: The head-mounted display system comprises: at least one diffusive optical element; at least one out-coupling optical element; at least one mask comprising at least one mask opening; at least one illumination in-coupling optical element configured to in-couple light from at least one illumination source into a light-guiding component; an image projector configured to in-couple an image; an at least one illumination source configured to in-couple light into at least one illumination in-coupling optical element; an eyepiece; a curved light-guiding component; a light-guiding component forming a portion of a frame; and / or two light-guiding components disposed on opposite sides of at least one out-coupling optical element.SELECTED DRAWING: Figure 10A

Description

[Technical Field]

[0001] (Priority Claim) This application claims the benefit of priority to U.S. Provisional Patent Application No. 62 / 694,366, filed July 5, 2018, which is incorporated herein by reference in its entirety.

[0002] The present disclosure relates to display systems, and more particularly to augmented and virtual reality display 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 can 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 input, while augmented reality, or "AR," scenarios typically involve the presentation of digital or virtual image information as an augmentation to the user's visualization of the real world around them. Mixed reality, or "MR," scenarios are a type of AR scenario that typically involve virtual objects integrated into and responsive to the natural world. For example, MR scenarios may include AR image content that appears to be occluded by or otherwise perceived to interact with objects in the real world.

[0004] Referring to FIG. 1 , an augmented reality scene 10 is depicted. A user of the AR technology sees a real-world park-like setting 20 featuring people, trees, a building in the background, and a concrete platform 30. The user 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. These elements 50, 40 are "virtual" in that they 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 or VR technology.

[0006] Physical LEDs for IR eye tracking impose mechanical installation constraints that are aesthetically undesirable and result in suboptimal eye tracking performance. Improved system configurations for illuminating a user's eyes with IR light without significantly impacting the overall system mass, power, volume, and cost are desired. Summary of the Invention [Means for solving the problem]

[0007] Various examples are provided below.

[0008] 1. A head mounted display system configured to project light onto an eye of a user wearing the head mounted display system to display content within the user's field of view, comprising: a frame configured to be supported on a user's head; and an image projector configured to project an image; at least one illumination source; a light guiding component configured to be positioned in front of one of the user's eyes when the frame is worn by the user; and at least one illumination in-coupling optical element configured to in-couple light from the at least one illumination source into the light directing component so as to direct light from the at least one illumination source therein; at least one diffusing optical element disposed on the light directing component so as to be positioned in front of one of the user's eyes when the frame is worn by a user, the at least one diffusing optical element configured to diffusively couple light from the at least one illumination source out of the light directing component; A head-mounted display system comprising:

[0009] 1. A head mounted display system configured to project light onto an eye of a user wearing the head mounted display system to display content within the user's field of view, comprising: a frame configured to be supported on a user's head; and an image projector configured to project an image; at least one illumination source; a light guiding component configured to be positioned in front of one of the user's eyes when the frame is worn by the user; and at least one illumination in-coupling optical element configured to in-couple light from the at least one illumination source into the light directing component so as to direct light from the at least one illumination source therein; at least one outcoupling optical element disposed on the light guiding component so as to be positioned in front of one of the user's eyes when the frame is worn by a user, the at least one outcoupling optical element configured to couple light from the at least one illumination source out of the light guiding component and to diverge the light coupled out of the light guiding component to match light originating from a location at a distance in front of the light guiding component; A head-mounted display system comprising:

[0010] 1. A head mounted display system configured to project light onto an eye of a user wearing the head mounted display system to display content within the user's field of view, comprising: a frame configured to be supported on a user's head; and an image projector configured to project an image; at least one illumination source; a light guiding component configured to be positioned in front of one of the user's eyes when the frame is worn by the user; and at least one illumination in-coupling optical element configured to in-couple light from the at least one illumination source into the light directing component so as to direct light from the at least one illumination source therein; at least one mask including at least one mask opening disposed on the light directing component so as to be positioned in front of one of the user's eyes when the frame is worn by the user, the at least one mask and the at least one mask opening configured to couple light from the at least one illumination source out of the light directing component through the at least one mask opening; A head-mounted display system comprising:

[0011] 1. A head mounted display system configured to project light onto an eye of a user wearing the head mounted display system to display content within the user's field of view, comprising: a frame configured to be supported on a user's head; and an image projector configured to project an image; at least one illumination source; a light guiding component configured to be positioned in front of one of the user's eyes when the frame is worn by the user; and at least one illumination in-coupling optical element configured to in-couple light from the at least one illumination source into the light directing component so as to guide the light from the at least one illumination source therein, the at least one in-coupling optical element comprising a prism; wherein the light directing component is configured such that light from an illumination source that is directed within the light directing component is coupled out of the light directing component.

[0012] 1. A head mounted display system configured to project light onto an eye of a user wearing the head mounted display system to display content within the user's field of view, comprising: a frame configured to be supported on a user's head; and an image projector configured to project an image; at least one illumination source; a light guiding component configured to be positioned in front of one of the user's eyes when the frame is worn by the user; and at least one illumination in-coupling optical element configured to in-couple light from the at least one illumination source into the light directing component so as to direct light from the at least one illumination source therein; Equipped with the light directing component is configured such that light from the illumination source that is directed within the light directing component is coupled out of the light directing component; the image projector is configured to incouple an image, and the at least one illumination source is configured to incouple light into the at least one illumination incoupling optical element; Head-mounted display system.

[0013] 1. A head mounted display system configured to project light onto an eye of a user wearing the head mounted display system to display content within the user's field of view, comprising: a frame configured to be supported on a user's head; and an image projector configured to project an image; at least one illumination source; a light guiding component configured to be positioned in front of one of the user's eyes when the frame is worn by the user; and at least one illumination in-coupling optical element configured to in-couple light from the at least one illumination source into the light directing component so as to direct light from the at least one illumination source therein; an eyepiece configured to direct light into the user's eye and display augmented reality image content in the user's field of view, at least a portion of the eyepiece being transparent and positioned at a location in front of the user's eye when the user wears the frame such that the transparent portion transmits light from an environment in front of the user to the user's eye and provides a view of the environment in front of the user; wherein the eyepiece comprises a waveguide and at least one image incoupling optical element configured to incoupling light from an image projector into the waveguide so as to guide the light from the image projector therein.

[0014] 1. A head mounted display system configured to project light onto an eye of a user wearing the head mounted display system to display content within the user's field of view, comprising: a frame configured to be supported on a user's head; and an image projector configured to project an image; at least one illumination source; a light guiding component configured and curved to be positioned in front of one of the user's eyes when the frame is worn by the user; and at least one illumination in-coupling optical element configured to in-couple light from the at least one illumination source into the light directing component so as to direct light from the at least one illumination source therein; wherein the light directing component is configured such that light from an illumination source that is directed within the light directing component is coupled out of the light directing component.

[0015] 1. A head mounted display system configured to project light onto an eye of a user wearing the head mounted display system to display content within the user's field of view, comprising: a frame configured to be supported on a user's head; and an image projector configured to project an image; at least one illumination source; a light guiding component configured to be positioned in front of one of the user's eyes when the frame is worn by the user, the light guiding component forming part of the frame; at least one illumination in-coupling optical element configured to in-couple light from the at least one illumination source into the light directing component so as to direct light from the at least one illumination source therein; wherein the light directing component is configured such that light from an illumination source that is directed within the light directing component is coupled out of the light directing component.

[0016] 1. A head mounted display system configured to project light onto an eye of a user wearing the head mounted display system to display content within the user's field of view, comprising: a frame configured to be supported on a user's head; and an image projector configured to project an image; at least one illumination source; a light guiding component configured to be positioned in front of one of the user's eyes when the frame is worn by the user; and at least one illumination in-coupling optical element configured to in-couple light from the at least one illumination source into the light directing component so as to direct light from the at least one illumination source therein; at least one outcoupling optical element disposed on the light directing component so as to be positioned in front of one of the user's eyes when the frame is worn by a user, the at least one outcoupling optical element configured to couple light from the at least one illumination source out of the light directing component; wherein the light directing component comprises two light directing components disposed on opposite sides of the at least one out-coupling optical element.

[0017] 10. The system of any preceding embodiment, wherein the image projector comprises a visible light source and a modulator.

[0018] 10. The system of any preceding embodiment, wherein the light modulator comprises a spatial light modulator.

[0019] 10. The system of any of the preceding examples, wherein the at least one illumination source comprises an infrared (IR) light source configured to emit IR light.

[0020] 10. The system of any of the preceding examples, wherein the at least one illumination source comprises a visible light source configured to emit visible light.

[0021] 10. The system of any of the preceding examples, wherein the light directing component comprises a material transparent to visible light having a refractive index sufficient to direct light from the at least one illumination source within the light directing component by total internal reflection.

[0022] A system as described in any of the above examples, wherein at least a portion of the light directing component is transparent and positioned in a location in front of the user's eye when the user wears the frame so as to transmit light from the environment in front of the user to the user's eye and provide a view of the environment in front of the user.

[0023] 10. The system of any of the preceding embodiments, wherein the at least one illumination in-coupling optical element comprises at least one prism.

[0024] 10. The system of any of the preceding examples, further comprising at least one image incoupling optical element configured to incoupling light from the image projector into the light directing component so as to direct light from the image projector therein.

[0025] 10. The system of any of the preceding examples, wherein the image projector is configured to incoupling an image and the at least one illumination source is configured to incoupling light into the at least one illumination incoupling optical element.

[0026] The system of any of the above examples further comprises an eyepiece configured to direct light into the user's eye and display augmented reality image content in the user's field of view, at least a portion of the eyepiece being transparent and positioned in a location in front of the user's eye when the user wears the frame so as to transmit light from the environment in front of the user to the user's eye and provide a view of the environment in front of the user.

[0027] A system as described in any of the above examples, wherein the eyepiece lens comprises a waveguide and at least one image incoupling optical element configured to incoupling light from the image projector into the waveguide so as to guide the light from the image projector therein.

[0028] 10. The system of any of the preceding embodiments, wherein the light directing component is disposed on an inner portion of the eyepiece, the inner portion being between the user's eye and the eyepiece.

[0029] 10. The system of any of the preceding embodiments, wherein the light-guiding component is disposed on an outer portion of the eyepiece, the outer portion being between the environment and the eyepiece.

[0030] 10. The system of any preceding embodiment, wherein the light directing component is curved.

[0031] 10. The system of any preceding embodiment, wherein the light directing component has the shape of a portion of a cylinder.

[0032] 10. The system of any preceding embodiment, wherein the light directing component comprises a shield or visor attached to the frame.

[0033] 10. The system of any preceding embodiment, wherein the shield or visor is disposed on an interior portion of the display system.

[0034] 10. The system of any preceding embodiment, wherein the shield or visor is disposed on an outer portion of the display system.

[0035] The system of any preceding embodiment, wherein the light directing component forms part of the frame.

[0036] 10. The system of any of the preceding examples, wherein the at least one diffusing optical element is configured to couple light from the at least one illumination source out of the light directing component and towards the user's eye.

[0037] A system as described in any of the above examples, wherein the at least one diffusing optical element is configured to couple light from the at least one illumination source out of the light guiding component toward the user's eyes and toward an environment in front of the user.

[0038] The system of any of the previous examples, wherein at least one mask blocks light guided within the light directing component from exiting the light directing component.

[0039] 10. The system of any preceding embodiment, wherein the at least one mask reflects light from the at least one illumination source back into the light directing component.

[0040] 10. The system of any of the preceding embodiments, wherein the at least one mask is dichroic, reflecting certain wavelengths emitted by the at least one illumination source and transmitting other wavelengths not emitted by the at least one illumination source.

[0041] 10. The system of any of the preceding examples, wherein the at least one mask is dichroic, reflecting certain infrared wavelengths emitted by the at least one illumination source and transmitting other visible wavelengths not emitted by the at least one illumination source.

[0042] 10. The system of any preceding embodiment, wherein the at least one mask is configured to absorb light emitted by the illumination source.

[0043] The system of any of the preceding examples, wherein the at least one mask opening is about 10 μm in diameter.

[0044] The system of any of the previous examples, wherein the at least one diffusing optical element extends across an area that is less than 5% of an area of ​​the at least one light directing component.

[0045] The system of any of the previous examples, wherein the at least one mask opening extends across an area that is less than 5% of an area of ​​the at least one light directing component.

[0046] 10. The system of any of the preceding examples, further comprising a light redirecting element configured to direct light received from the at least one illumination in-coupling optical element into the light directing component such that the light directing component redirects the light to the at least one diffusing optical element.

[0047] 10. The system of any of the preceding examples, further comprising a light redirecting element configured to direct light received from the at least one illumination in-coupling optical element into the light directing component such that the light directing component redirects the light to the at least one mask opening.

[0048] 10. The system of claim 1, further comprising a light redirecting element configured to direct light received from the at least one illumination in-coupling optical element into the light guiding component such that the light guiding component redirects the light to the at least one out-coupling element.

[0049] 10. The system of any preceding example embodiment, wherein the light redirecting element comprises an orthogonal pupil expander.

[0050] 10. The system of any of the preceding examples, further comprising at least one camera configured to image the user's eye using light from the at least one illumination source reflected from the eye.

[0051] 10. The system of any of the preceding examples, wherein the at least one camera comprises an eye-tracking camera configured to communicate with electronics configured to track movement of the eye based on images from the at least one camera.

[0052] 10. The system of any preceding embodiment, wherein the light directing component has a circular shape.

[0053] 10. The system of any of the preceding examples, wherein the light directing component comprises two light directing components positioned on opposite sides of the at least one diffusing optical element.

[0054] The system of any of the preceding examples, wherein the at least one light directing component comprises first and second light directing components disposed on opposite sides of a diffusion film.

[0055] 10. The system of any of the preceding examples, wherein the at least one diffusing optical element comprises a pair of diffusing optical elements disposed on opposite sides of the light directing component.

[0056] The system of any of the preceding examples, wherein the at least one diffusing optical element comprises first and second diffusing films disposed on opposite sides of the light directing component.

[0057] The system of any of the above examples, wherein the at least one diffusive optical element comprises first and second diffusive optical elements configured to direct light into distributions oriented in different first and second directions.

[0058] The system of any of the above examples, wherein the at least one diffusing optical element comprises first and second diffusing optical elements configured to selectively direct light having first and second wavelengths into distributions oriented in different first and second directions, respectively, and the at least one illumination source comprises first and second light sources that selectively emit the first and second wavelengths, respectively.

[0059] 10. The system of any of the preceding embodiments, wherein the at least one illumination source comprises a plurality of illumination sources.

[0060] 10. The system of any of the preceding embodiments, wherein the at least one illumination source comprises a plurality of illumination sources, and the at least one diffusing optical element directs light from different illumination sources into individual distributions oriented in different directions.

[0061] The system of any of the preceding examples, wherein the at least one illumination source comprises a plurality of illumination sources, and the at least one diffusing optical element directs light from the different illumination sources as if they originate from different, separate locations in front of the at least one light-guiding component.

[0062] 10. The system of any of the preceding examples, wherein the at least one illumination source comprises a laser, an LED, or a vertical cavity surface emitting laser (VCSEL).

[0063] 10. The system of any of the preceding embodiments, wherein the at least one illumination source further comprises at least one filter.

[0064] 10. The system of any of the preceding embodiments, wherein the at least one diffractive optical element is refractive, reflective, diffractive, or any combination thereof.

[0065] The system of any of the above examples, wherein the at least one diffusing optical element comprises one or more diffuser sheets, one or more light shaping diffusers, one or more diffuser films, one or more etchings, one or more transmissive optical elements, one or more particles, one or more irregular surfaces, one or more surface relief structures, PTFE, Teflon, frosted glass, milk glass, gray glass, one or more white surfaces, colored gels, one or more holograms, or any combination thereof.

[0066] A system described in any of the above examples, wherein the at least one diffusing optical element is wavelength selective such that it substantially selectively diffuses one or more wavelengths of light emitted from the at least one illumination source and does not diffuse others.

[0067] The system of any of the above examples, wherein the system includes a plurality of diffusing optical elements and at least one illumination source emitting a plurality of wavelength bands of light, wherein different ones of the diffusing optical elements selectively diffuse respective ones of the plurality of wavelength bands from the at least one illumination source.

[0068] 10. The system of any of the preceding embodiments, wherein the at least one diffusing optical element does not redirect visible light from the environment.

[0069] 10. The system of any preceding embodiment, wherein the at least one diffusing optical element is configured to direct light from the illumination source towards the environment.

[0070] 10. The system of claim 1, wherein the at least one illumination source comprises an infrared source configured to output infrared light, and the at least one diffusing optical element is configured to direct the infrared light from the at least one illumination source toward the environment to provide depth sensing.

[0071] The system of any of the above examples, wherein the at least one illumination source comprises a visible light source configured to output visible light, and the at least one diffusing optical element is configured to direct the visible light from the at least one illumination source towards the environment and provide indicia to a non-user.

[0072] 10. The system of claim 1, wherein the at least one illumination source comprises a visible light source configured to output visible light, and the at least one diffusing optical element is configured to direct the visible light from the at least one illumination source toward the eye and provide an indication to a user.

[0073] 10. The system of claim 1, wherein the at least one illumination source comprises a visible light source configured to output visible light, and the at least one diffusing optical element is configured to direct the visible light from the at least one illumination source toward the periphery of the eye.

[0074] 10. The system of claim 1, wherein the at least one illumination source comprises a visible light source, an infrared source, or both, configured to output light, and the at least one diffusing optical element is configured to direct light from the at least one illumination source toward the environment and provide a signal or reference point to an external sensor or external imaging sensor.

[0075] The system of any of the above examples, wherein the at least one illumination source comprises a visible light source, an infrared source, or both configured to output light, and the at least one diffusing optical element is configured to direct light from the at least one illumination source toward the user and provide a signal or reference point to an external sensor or external imaging sensor.

[0076] The system of any of the previous examples, wherein the at least one outcoupling optical element extends across an area that is less than 5% of an area of ​​the at least one light guiding component.

[0077] 10. The system of any of the preceding examples, wherein the light guiding component comprises two light guiding components disposed on opposite sides of the at least one outcoupling optical element.

[0078] The system of any of the previous examples, wherein the at least one light directing component comprises first and second light directing components disposed on opposite sides of the outcoupling optical film.

[0079] 10. The system of any of the preceding embodiments, wherein the at least one outcoupling optical element comprises a pair of outcoupling optical elements disposed on opposite sides of the light directing component.

[0080] 10. The system of any of the preceding examples, wherein the at least one outcoupling optical element comprises first and second outcoupling optical films disposed on opposite sides of the light directing component.

[0081] The system of any of the above examples, wherein the at least one outcoupling optical element comprises first and second outcoupling optical elements configured to direct light into distributions oriented in different first and second directions.

[0082] The system of any of the above examples, wherein the at least one outcoupling optical element comprises first and second outcoupling optical elements configured to selectively direct light having first and second wavelengths into distributions oriented in different first and second directions, respectively, and the at least one illumination source comprises first and second light sources that selectively emit the first and second wavelengths, respectively.

[0083] 10. The system of any of the preceding embodiments, wherein the at least one illumination source comprises a plurality of illumination sources.

[0084] 10. The system of any of the preceding embodiments, wherein the at least one illumination source comprises a plurality of illumination sources, and the at least one outcoupling optical element directs light from different illumination sources into individual distributions oriented in different directions.

[0085] The system of any of the preceding examples, wherein the at least one illumination source comprises a plurality of illumination sources, and the at least one outcoupling optical element directs light from the different illumination sources as if they originate from different, separate locations in front of the at least one light-guiding component.

[0086] 10. The system of any of the preceding examples, wherein the at least one illumination source comprises a laser, an LED, or a vertical cavity surface emitting laser (VCSEL).

[0087] 10. The system of any of the preceding embodiments, wherein the at least one illumination source further comprises at least one filter.

[0088] 10. The system of any of the preceding embodiments, wherein the at least one outcoupling optical element is refractive, reflective, diffractive, or any combination thereof.

[0089] The system of any of the above examples, wherein the at least one outcoupling optical element comprises one or more diffuser sheets, one or more light shaping diffusers, one or more diffuser films, one or more etchings, one or more transmissive optical elements, one or more particles, one or more irregular surfaces, one or more surface relief structures, PTFE, Teflon, frosted glass, milk glass, gray glass, one or more white surfaces, colored gels, one or more holograms, or any combination thereof.

[0090] 10. The system of any of the preceding embodiments, wherein the at least one outcoupling optical element is wavelength selective such that it interacts substantially only with a wavelength band of light emitted from the at least one illumination source.

[0091] 10. The system of any of the preceding embodiments, wherein the system comprises a plurality of outcoupling optical elements and at least one illumination source emitting a plurality of wavelength bands of light, each outcoupling optical element being wavelength selective such that it interacts substantially only with a different wavelength band of light emitted from the at least one illumination source.

[0092] 10. The system of any of the preceding embodiments, wherein the at least one outcoupling optical element does not redirect visible light from the environment.

[0093] 10. The system of any of the preceding embodiments, wherein the at least one outcoupling optical element is configured to direct light from the illumination source towards the environment.

[0094] 10. The system of claim 1, wherein the at least one illumination source comprises an infrared source configured to output infrared light, and the at least one outcoupling optical element is configured to direct the infrared light from the at least one illumination source toward the environment to provide depth sensing.

[0095] The system of any of the above examples, wherein the at least one illumination source comprises a visible light source configured to output visible light, and the at least one outcoupling optical element is configured to direct the visible light from the at least one illumination source towards the environment to provide an indication to a non-user.

[0096] 10. The system of claim 1, wherein the at least one illumination source comprises a visible light source configured to output visible light, and the at least one outcoupling optical element is configured to direct the visible light from the at least one illumination source toward the eye to provide an indication to a user.

[0097] 10. The system of claim 1, wherein the at least one illumination source comprises a visible light source configured to output visible light, and the at least one outcoupling optical element is configured to direct the visible light from the at least one illumination source toward the periphery of the eye.

[0098] 10. The system of claim 1, wherein the at least one illumination source comprises a visible light source, an infrared source, or both, configured to output light, and the at least one outcoupling optical element is configured to direct light from the at least one illumination source toward the environment and provide a signal or reference point to an external sensor or external imaging sensor.

[0099] The system of any of the above examples, wherein the at least one illumination source comprises a visible light source, an infrared source, or both configured to output light, and the at least one outcoupling optical element is configured to direct light from the at least one illumination source toward the user and provide a signal or reference point to a sensor or external imaging sensor.

[0100] 10. A system according to any preceding claim, wherein the image projector and the illumination source share the same in-coupling optical elements and light directing components.

[0101] 10. The system of any of the preceding embodiments, wherein the at least one outcoupling optical element comprises at least one diffusing optical element, or at least one diffusing film, or any combination thereof.

[0102] 10. The system of any of the preceding embodiments, wherein the at least one outcoupling optical element comprises at least one diffractive optical element, or at least one holographic optical element, or any combination thereof. The present invention provides, for example, the following. (Item 1) 1. A head mounted display system configured to project light onto an eye of a user wearing the head mounted display system to display content within a field of view of the user, the head mounted display system comprising: a frame configured to be supported on the user's head; an image projector configured to project an image; at least one illumination source; a light guiding component configured to be positioned in front of one of the user's eyes when the frame is worn by the user; and at least one illumination in-coupling optical element, the at least one illumination in-coupling optical element configured to incouple light from the at least one illumination source into the light directing component so as to guide the light from the at least one illumination source therein; at least one diffusing optical element, the at least one diffusing optical element being disposed on the light directing component to be positioned in front of one of the user's eyes when the frame is worn by a user, the at least one diffusing optical element being configured to diffusively couple light from the at least one illumination source out of the light directing component; A head-mounted display system comprising: (Item 2) Item 1, wherein the image projector comprises a visible light source and a modulator. (Item 3) Item 3. The system of item 2, wherein the light modulator comprises a spatial light modulator. (Item 4) Item 10. The system of item 1, wherein the at least one illumination source comprises an infrared (IR) light source configured to emit IR light. (Item 5) Item 10. The system of item 1, wherein the light directing component comprises a material transparent to visible light having a refractive index sufficient to direct light from the at least one illumination source within the light directing component by total internal reflection. (Item 6) Item 10. The system of item 1, wherein at least a portion of the light-guiding component is transparent and positioned in a location in front of the user's eyes when the user wears the frame so as to transmit light from the environment in front of the user to the user's eyes and provide a view of the environment in front of the user. (Item 7) Item 10. The system of item 1, wherein the at least one diffusing optical element is configured to couple light from the at least one illumination source out of the light directing component toward the user's eye. (Item 8) Item 10. The system of item 1, wherein the at least one diffusing optical element is configured to couple light from the at least one illumination source out of the light directing component toward an eye of a user and toward an environment in front of the user. (Item 9) Item 10. The system of item 1, wherein the at least one diffusing optical element extends across an area that is less than 5% of an area of ​​the at least one light directing component. (Item 10) Item 10. The system of item 1, wherein the at least one light guiding component comprises first and second light guiding components disposed on opposite sides of a diffusion film. (Item 11) Item 10. The system of item 1, wherein the at least one diffusing optical element comprises a pair of diffusing optical elements positioned on opposite sides of the light directing component. (Item 12) Item 10. The system of item 1, wherein the at least one diffusing optical element comprises first and second diffusing films disposed on opposite sides of the light directing component. (Item 13) Item 10. The system of item 1, wherein the at least one diffusing optical element comprises first and second diffusing optical elements configured to direct light into distributions oriented in different first and second directions. (Item 14) Item 1, the system comprising: the at least one diffusing optical element comprising first and second diffusing optical elements configured to selectively direct light having first and second wavelengths into distributions oriented in different first and second directions, respectively; and the at least one illumination source comprising first and second light sources selectively emitting the first and second wavelengths, respectively. (Item 15) Item 10. The system of item 1, wherein the at least one illumination source comprises a plurality of illumination sources, and the at least one diffusing optical element directs light from different illumination sources into individual distributions oriented in different directions. (Item 16) Item 10. The system of item 1, wherein the at least one illumination source comprises a plurality of illumination sources, and the at least one diffusing optical element directs light from the different illumination sources as if they originate from different individual locations in front of the at least one light directing component. (Item 17) Item 10. The system of item 1, wherein the at least one diffractive optical element is refractive, reflective, diffractive, or any combination thereof. (Item 18) Item 10. The system of item 1, wherein the at least one diffusing optical element comprises one or more diffuser sheets, one or more light shaping diffusers, one or more diffuser films, one or more etchings, one or more transmissive optical elements, one or more particles, one or more irregular surfaces, one or more surface relief structures, PTFE, Teflon, frosted glass, milk glass, gray glass, one or more white surfaces, colored gels, one or more holograms, or any combination thereof. (Item 19) Item 10. The system of item 1, wherein the at least one diffusing optical element is wavelength selective such that it substantially selectively diffuses one or more wavelengths of light emitted from the at least one illumination source and does not diffuse others. (Item 20) Item 10. The system of item 1, comprising a plurality of diffusing optical elements and at least one illumination source emitting a plurality of wavelength bands of light, different ones of the diffusing optical elements selectively diffusing respective ones of the plurality of wavelength bands from the at least one illumination source. (Item 21) Item 10. The system of item 1, wherein the at least one diffusing optical element does not redirect visible light from the environment. [Brief explanation of the drawings]

[0103] [Figure 1] FIG. 1 illustrates a user's view of an augmented reality (AR) device.

[0104] [Figure 2] FIG. 2 illustrates a conventional display system for simulating a three-dimensional image for a user.

[0105] [Figure 3] 3A-3C illustrate the relationship between the radius of curvature and the radius of focus.

[0106] [Figure 4A] Figure 4A illustrates a representation of the accommodation-vergence response of the human visual system.

[0107] [Figure 4B] FIG. 4B illustrates an example of different accommodation and convergence states of a pair of a user's eyes.

[0108] [Figure 4C] FIG. 4C illustrates an example of a top-down view representation of a user viewing content through a display system.

[0109] [Figure 4D] FIG. 4D illustrates another example of a top-down view representation of a user viewing content through a display system.

[0110] [Figure 5] FIG. 5 illustrates aspects of an approach for simulating three-dimensional images by correcting for wavefront divergence.

[0111] [Figure 6] FIG. 6 illustrates an embodiment of a waveguide stack for outputting image information to a user.

[0112] [Figure 7] FIG. 7 illustrates an example of an output beam output by a waveguide.

[0113] [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.

[0114] [Figure 9A] FIG. 9A illustrates a cross-sectional side view of an example of a set of stacked waveguides, each including an internal coupling optical element.

[0115] [Figure 9B] FIG. 9B illustrates a perspective view of the multiple stacked waveguide embodiment of FIG. 9A.

[0116] [Figure 9C] FIG. 9C illustrates a top-down plan view of the multiple stacked waveguide embodiment of FIGS. 9A and 9B.

[0117] [Figure 9D] FIG. 9D illustrates an example of a wearable display system.

[0118] [Figure 10A]10A-10D illustrate perspective views of a light directing component configured to project light from an illumination source into a user's eye so that the light appears to originate from a virtual source in front of the user's eye beyond the light directing component (e.g., in the far field). In some designs, the light directing component comprises an eyepiece of a head-mounted display that is also configured to project an image from the display into the user's eye. [Figure 10B] 10A-10D illustrate perspective views of a light directing component configured to project light from an illumination source into a user's eye so that the light appears to originate from a virtual source in front of the user's eye beyond the light directing component (e.g., in the far field). In some designs, the light directing component comprises an eyepiece of a head-mounted display that is also configured to project an image from the display into the user's eye. [Figure 10C] 10A-10D illustrate perspective views of a light directing component configured to project light from an illumination source into a user's eye so that the light appears to originate from a virtual source in front of the user's eye beyond the light directing component (e.g., in the far field). In some designs, the light directing component comprises an eyepiece of a head-mounted display that is also configured to project an image from the display into the user's eye. [Figure 10D] 10A-10D illustrate perspective views of a light directing component configured to project light from an illumination source into a user's eye so that the light appears to originate from a virtual source in front of the user's eye beyond the light directing component (e.g., in the far field). In some designs, the light directing component comprises an eyepiece of a head-mounted display that is also configured to project an image from the display into the user's eye.

[0119] [Figure 11A]11A-11B illustrate perspective views of a light guiding component having a mask with multiple openings therein through which light can exit the light guiding component, thereby producing a localized (e.g., point) illumination source. [Figure 11B] 11A-11B illustrate perspective views of a light guiding component having a mask with multiple openings therein through which light can exit the light guiding component, thereby producing a localized (e.g., point) illumination source.

[0120] [Figure 12A] 12A-12B illustrate perspective views of a light guiding component and one or more outcoupling optical elements comprising diffusive optical elements or scattering regions that scatter light guided within the light guiding component, in this example producing multiple distinct, localized (e.g., point) illumination sources. [Figure 12B] 12A-12B illustrate perspective views of a light guiding component and one or more outcoupling optical elements comprising diffusive optical elements or scattering regions that scatter light guided within the light guiding component, in this example producing multiple distinct, localized (e.g., point) illumination sources.

[0121] [Figure 13A] 13A-13B illustrate a light directing component comprising an outer cover of an eyepiece of a head-mounted display. In this embodiment, the light directing component comprising the outer cover is curved. In addition, one or more outcoupling optical elements comprising a diffusing optical element scatter light guided within the light directing component out of the light directing component. [Figure 13B] 13A-13B illustrate a light directing component comprising an outer cover of an eyepiece of a head-mounted display. In this embodiment, the light directing component comprising the outer cover is curved. In addition, one or more outcoupling optical elements comprising a diffusing optical element scatter light guided within the light directing component out of the light directing component.

[0122] [Figure 14A] 14A-14B illustrate a light directing component comprising an inner cover for an eyepiece of a head-mounted display. One or more outcoupling optical elements comprising a plurality of diffusing optical elements are positioned relative to the light directing component to allow light guided within the light directing component to exit therefrom. [Figure 14B] 14A-14B illustrate a light directing component comprising an inner cover for an eyepiece of a head-mounted display. One or more outcoupling optical elements comprising a plurality of diffusing optical elements are positioned relative to the light directing component to allow light guided within the light directing component to exit therefrom.

[0123] [Figure 15A] 15A-15B illustrate a light directing component integrated into the frame of a head-mounted display system. In this embodiment, one or more outcoupling optical elements, e.g., comprising diffusing optical elements or holes, are positioned on the light directing portion of the frame to allow light guided therein to exit. [Figure 15B] 15A-15B illustrate a light directing component integrated into the frame of a head-mounted display system. In this embodiment, one or more outcoupling optical elements, e.g., comprising diffusing optical elements or holes, are positioned on the light directing portion of the frame to allow light guided therein to exit.

[0124] [Figure 16] FIG. 16 illustrates a circular-shaped light-guiding component including a ring-shaped outcoupling element, for example with an annular-shaped diffusing film or diffractive optical element.

[0125] [Figure 17-1]FIG. 17A illustrates first and second light guiding components stacked on top of each other. In this example, the first and second light guiding components are separated by an outcoupling optical element, e.g., comprising a diffusive or diffractive optical element configured to couple light guided within the first and second light guiding components out of the light guiding components. In some implementations, the outcoupling is bidirectional, with light exiting the front and back of the paired light guiding components. FIG. 17B illustrates a light guiding component comprising first and second outcoupling optical elements disposed on opposite sides of the light guiding component and coupling light guided within the light guiding component out of the light guiding component. In some examples, the first and second outcoupling optical elements may be configured to provide bidirectional outcoupling, such that light exits the front and back of the light guiding component and the paired outcoupling optical elements.

[0126] [Figure 17-2] 17C illustrates first and second light guiding components on opposite sides of one or more outcoupling optical elements, e.g., comprising a diffractive or diffractive optical element configured to couple light guided within the first and second light guiding components out of the light guiding components. In some implementations, the outcoupling is bidirectional, with light being injected forward and backward through the pair of light guiding components. As shown, the first and second light guiding components are circularly shaped and the outcoupling optical element is annularly shaped.

[0127] The drawings are provided to illustrate example embodiments and are not intended to limit the scope of the present disclosure. Like reference numbers refer to like parts throughout. DETAILED DESCRIPTION OF THE INVENTION

[0128] The AR system may display virtual content to a user or viewer while still allowing the user to see the world around them. Preferably, this content is displayed on a head-mounted display, for example, as part of eyewear, that projects image information into the user's eyes. In addition, the display may also transmit light from the surrounding environment to the user's eyes, allowing a view of that surrounding environment. As used herein, it should be understood that a "head-mounted" or "head-mountable" display is a display that can be mounted on the viewer's or user's head.

[0129] In some AR systems, the multiple waveguides may be configured to form virtual images at multiple virtual depth planes (also simply referred to herein as "depth planes"). Different waveguides of the multiple waveguides may have different refractive powers and may be formed at different distances from the user's eyes. The display system may also include multiple lenses that provide, or additionally provide, refractive power. The refractive power of the waveguides and / or lenses may provide images at different virtual depth planes. Undesirably, the waveguides and lenses may each increase the overall thickness, weight, and cost of the display.

[0130] Advantageously, in various embodiments described herein, an adaptive lens assembly may be utilized to provide variable optical power, e.g., to modify the wavefront divergence of light propagating through the lens assembly and provide a virtual depth plane at different perceived distances from the user. The adaptive lens assembly may include a pair of waveplate lenses with a switchable waveplate disposed therebetween. The first and second waveplate lenses may each be configured to alter the polarization state of light passing therethrough, and the switchable waveplate may be switchable between multiple states, e.g., a first state that allows light to pass without changing the polarization of the light, and a second state that alters the polarization of the light (e.g., by changing the handedness of the polarization). In some embodiments, one or both of the waveplate lenses may be switchable between these first and second states, and the intervening switchable waveplate may be omitted.

[0131] It should be understood that an adaptive lens assembly may comprise a stack of multiple waveplate lenses and multiple switchable waveplates. For example, an adaptive lens assembly may comprise multiple subassemblies comprising pairs of waveplate lenses with intervening switchable waveplates. In some embodiments, an adaptive lens assembly may include alternating waveplate lenses and switchable waveplates. Advantageously, such an alternating arrangement allows for thickness and weight reduction by having adjacent switchable waveplates share a common waveplate lens. In some embodiments, more than two discrete levels of optical power may be provided by switching the states of various combinations of switchable plates in the stack.

[0132] In some embodiments, the adaptive lens assembly, together with the waveguide assembly, forms a display device and forms images at different virtual depth planes. In various embodiments, the display device includes a pair of adaptive lens assemblies interposed by a waveguide assembly. The waveguide assembly includes a waveguide configured to propagate light (e.g., visible light) therein (e.g., via total internal reflection) and to outcouple the light. For example, the light may be outcoupled along an optical axis direction normal to a major surface of the waveguide. One of the pair of adaptive lens assemblies may be formed on a first side of the waveguide assembly and may be configured to provide variable refractive power, modify the wavefront of the light passing through the adaptive lens assembly, and form images at each of a plurality of virtual depth planes. For example, the adaptive lens assembly may converge or diverge the outcoupled light received from the waveguide assembly. To compensate for modifications of the real-world view due to convergence or divergence of ambient light propagating through the adaptive lens assembly and / or the waveguide assembly, the other of the pair of adaptive lens assemblies is additionally provided on a second side of the waveguide assembly opposite the first side. When the switchable waveplates of each adaptive lens assembly assume corresponding states, the adaptive lens assemblies may have optical powers with opposite signs such that the other of the adaptive lens assemblies corrects distortions caused by the adaptive lens assembly on the first side of the waveguide assembly.

[0133] Advantageously, utilizing a switchable waveplate switchable between two states for a continuously variable adaptive lens having a continuously variable optical element simplifies driving the adaptive lens assembly and reduces the computing power required to determine how to properly activate the adaptive lens assembly for a desired optical power. Additionally, by allowing the adaptive lens assembly to modify the wavefront divergence of light output by the waveguides, the number of waveguides required to provide multiple depth planes is reduced relative to an arrangement in which each waveguide provides a specific amount of wavefront divergence.

[0134] Reference is now made to the drawings, wherein like reference numerals refer to like parts throughout. Unless otherwise indicated, the drawings are schematic and are not necessarily drawn to scale. Exemplary Display System

[0135] FIG. 2 illustrates a conventional display system for simulating a three-dimensional image for a user. It should be understood that when a user's eyes are spaced apart and viewing a real object in space, each eye may have a slightly different view of the object, forming an image of the object at a different location on each eye's retina. This may be referred to as binocular disparity and may be utilized by the human visual system to provide the perception of depth. Conventional display systems simulate binocular disparity by presenting two distinct images 190, 200, one for each eye 210, 220, with slightly different views of the same virtual object, corresponding to the view of the virtual object as it would appear by each eye as if the virtual object were a real object at a desired depth. These images provide binocular cues that the user's visual system may interpret to derive the perception of depth.

[0136] Continuing with reference to FIG. 2 , images 190 and 200 are spaced apart from eyes 210 and 220 by a distance 230 on the z-axis. The z-axis is parallel to the optical axis of the viewer when the eye is fixating on an object at optical infinity directly in front of the viewer. Images 190 and 200 are flat and at a fixed distance from eyes 210 and 220. Based on slightly different views of the virtual object in the images presented to eyes 210 and 220, respectively, the eyes may necessarily rotate so that the image of the object falls on a corresponding point on each eye's retina, maintaining single binocular vision. This rotation may cause the gaze of each eye 210 and 220 to converge on a point in space where the virtual object is perceived to reside. As a result, providing three-dimensional images traditionally involves manipulating the convergence and divergence of the user's eyes 210 and 220 and providing binocular cues that the human visual system interprets to provide the perception of depth.

[0137] However, creating a realistic and comfortable perception of depth is challenging. It should be understood that light from an object at different distances from the eye has a wavefront with different amounts of divergence. Figures 3A-3C illustrate the relationship between distance and light ray divergence. The distance between the object and the eye 210 is represented in order of decreasing distances R1, R2, and R3. As shown in Figures 3A-3C, light rays become more divergent as the distance to the object decreases. Conversely, as the distance increases, the light rays become more collimated. In other words, the light field generated by a point (an object or portion of an object) can be said to have a spherical wavefront curvature that is a function of the distance the point is from the user's eye. As the curvature increases, the distance between the object and the eye 210 decreases. While only a single eye 210 is illustrated in Figures 3A-3C and various other figures herein for clarity of illustration, the discussion regarding the eye 210 may apply to both eyes 210 and 220 of the viewer.

[0138] Continuing with reference to Figures 3A-3C, light from an object that a viewer's eye is fixating may have different wavefront divergences. Due to the different wavefront divergences, the light may be focused differently by the eye's lens, which in turn may require the lens to assume a different shape to form a focused image on the eye's retina. If a focused image is not formed on the retina, the resulting retinal blur acts as an accommodative cue, causing the shape of the eye's lens to change until a focused image is formed on the retina. For example, the accommodative cue may induce relaxation or contraction of the ciliary muscles surrounding the eye's lens, thereby modulating the force applied to the suspensory ligaments that hold the lens, thus changing the shape of the eye's lens and thereby forming a focused image of the fixated object on the eye's retina (e.g., the fovea) until retinal blur of the fixated object is eliminated or minimized. The process by which the eye's lens changes shape can be referred to as accommodation, and the shape of the eye's lens required to form a focused image of a fixated object on the eye's retina (e.g., the fovea) can be referred to as the state of accommodation.

[0139] Referring now to Figure 4A, a representation of the accommodation-vergence response of the human visual system is illustrated. Eye movement to fixate an object causes the eye to receive light from the object, which forms an image on each of the eye's retinas. The presence of retinal blur in the image formed on the retina can provide a cue for accommodation, and the relative location of the image on the retina can provide a cue for vergence. Accommodation cues cause accommodation, resulting in the eye's lens adopting a specific accommodation state in which a focused image of the object is formed on the eye's retina (e.g., the fovea). Conversely, vergence cues cause vergence movements (eye rotations) so that the images formed on each retina of each eye are at corresponding retinal points, maintaining single binocular vision. In these positions, the eyes can be said to adopt a specific vergence state. Continuing with reference to FIG. 4A , accommodation can be understood as the process by which the eyes achieve a particular accommodation state, and convergence can be understood as the process by which the eyes achieve a particular convergence state. As shown in FIG. 4A , the accommodation and convergence states of the eyes can change when the user fixates on a different object. For example, the accommodated state can change when the user fixates on a new object at a different depth on the z-axis.

[0140] 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 convergence-divergence and accommodation. As previously mentioned, vergence-divergence movements of the two eyes relative to one another (e.g., eye rotation such that the pupils move toward or away from one another, converging the eyes' lines of sight and fixating on an object) are closely linked to accommodation of the eye's lenses. Under normal conditions, changing the shape of the eye's lenses and shifting focus from one object to another at a different distance will automatically produce a corresponding change in vergence-divergence to the same distance, a relationship known as the "accommodation-divergence reflex." Similarly, a change in vergence-divergence will induce a corresponding change in lens shape under normal conditions.

[0141] 4B, an example of different accommodation and convergence states of the eyes is illustrated. Paired eye 222a fixates an object at optical infinity, while paired eye 222b fixates an object 221 at less than optical infinity. Notably, the convergence states of each pair of eyes are different: paired eye 222a points straight ahead, while paired eye 222 converges on object 221. The accommodation states of the eyes forming each pair of eyes 222a and 222b are also different, as represented by the different shapes of lenses 210a, 220a.

[0142] Unfortunately, many users of conventional "3-D" display systems may find such systems uncomfortable or may not perceive any depth perception due to a mismatch between accommodation and convergence states in these displays. As previously mentioned, many stereoscopic or "3-D" display systems display a scene by providing a slightly different image to each eye. Such systems are uncomfortable for many viewers because, among other things, they simply provide different presentations of a scene, causing changes in the eyes' convergence states without corresponding changes in the eyes' accommodation states. Rather, images are presented by the display at a fixed distance from the eyes so that the eyes view all image information in a single accommodation state. Such an arrangement counters the "accommodation-vergence-divergence reflex" by causing changes in the convergence states without a corresponding change in the accommodation state. This mismatch is believed to cause viewer discomfort. Display systems that offer better alignment between accommodation and convergence-divergence movements may create a more realistic and comfortable simulation of three-dimensional images.

[0143] Without being limited by theory, it is believed that the human eye can typically interpret a finite number of depth planes to provide depth perception. As a result, a highly realistic simulation of perceived depth can be achieved by providing the eye with different presentations of images corresponding to each of these limited number of depth planes. In some embodiments, the different presentations may provide both vergence cues and matching cues for accommodation, thereby providing physiologically correct accommodation-vergence divergence matching.

[0144] 4B , two depth planes 240 are illustrated, corresponding to different distances in space from the eyes 210, 220. For a given depth plane 240, vergence-divergence cues may be provided by displaying appropriately different perspective images for each eye 210, 220. Additionally, for a given depth plane 240, the light forming the image provided to each eye 210, 220 may have a wavefront divergence corresponding to the light field generated by a point at the distance of that depth plane 240.

[0145] In the illustrated embodiment, the distance along the z-axis of depth plane 240 containing point 221 is 1 meter. As used herein, distance or depth along the z-axis may be measured with a zero point located at the exit pupil of the user's eye. Thus, depth plane 240 located at a depth of 1 meter corresponds to a distance of 1 meter away from the exit pupil of the user's eye on the optical axis of the eye with the eye pointed toward optical infinity. As an approximation, the depth or distance along the z-axis may be measured from a display (e.g., the surface of a waveguide) in front of the user's eye, and a value for the distance between the device and the exit pupil of the user's eye may be added. That value may be referred to as pupil distance and may correspond to the distance between the exit pupil of the user's eye and a display worn by the user in front of the eye. In practice, the value for pupil distance may be a normalized value generally used for all viewers. For example, pupil distance may be assumed to be 20 mm, and the depth plane at a depth of 1 meter may be at a distance of 980 mm in front of the display.

[0146] 4C and 4D, examples of matched accommodation-vergence-divergence distances and mismatched accommodation-vergence-divergence distances are illustrated, respectively. As illustrated in FIG. 4C, the display system may provide an image of a virtual object to each eye 210, 220. The image may cause the eyes 210, 220 to assume a convergence-divergence state in which the eyes converge on point 15 on the depth plane 240. In addition, the image may be formed by light having a wavefront curvature corresponding to the real object on that depth plane 240. As a result, the eyes 210, 220 assume an accommodation state in which the image is focused on the retinas of those eyes. Thus, the user may perceive the virtual object as being at point 15 on the depth plane 240.

[0147] It should be understood that the accommodation and convergence states of the eyes 210, 220 are each associated with a particular distance on the z-axis. For example, an object at a particular distance from the eyes 210, 220 will cause those eyes to assume a particular accommodation state based on the distance of the object. The distance associated with a particular accommodation state is referred to as the accommodation distance A. d Similarly, a particular convergence-divergence distance V associated with the eyes in a particular convergence-divergence state can be d Or, there exists a position relative to each other. When the accommodation distance and the convergence distance are matched, the relationship between accommodation and convergence is said to be physiologically correct. This is considered to be the most comfortable scenario for the viewer.

[0148] However, in a stereoscopic display, the accommodation distance and the convergence distance may not always be aligned. For example, as illustrated in FIG. 4D , images displayed to the eyes 210, 220 may be displayed with a wavefront divergence corresponding to the depth plane 240, and the eyes 210, 220 may be in a particular accommodation state in which points 15a, 15b on that depth plane are in focus. However, the images displayed to the eyes 210, 220 may provide convergence cues that cause the eyes 210, 220 to converge on a point 15 that is not located on the depth plane 240. As a result, in some embodiments, the accommodation distance corresponds to the distance from the exit pupils of the eyes 210, 220 to the depth plane 240, while the convergence distance corresponds to the greater distance from the exit pupils of the eyes 210, 220 to point 15. The accommodation distance is different from the convergence distance. As a result, there is an accommodation-vergence-divergence mismatch. Such a mismatch is considered undesirable and can cause discomfort to the user. The mismatch can be caused by distance (e.g., V d -A d ) and can be characterized in terms of diopters.

[0149] It should be understood that in some embodiments, a reference point other than the exit pupil of the eye 210, 220 may be used to determine the distance for determining accommodation-vergence mismatch, so long as the same reference point is used for accommodation distance and vergence distance. For example, the distance may be measured from the cornea to the depth plane, from the retina to the depth plane, from the eyepiece (e.g., a waveguide in a display device) to the depth plane, etc.

[0150] Without being limited by theory, it is believed that a user may still perceive an accommodation-vergence-divergence mismatch of up to about 0.25 diopters, up to about 0.33 diopters, and up to about 0.5 diopters as physiologically correct without the mismatch itself causing significant discomfort. In some embodiments, a display system disclosed herein (e.g., display system 250, FIG. 6 ) presents images to a viewer with an accommodation-vergence-divergence mismatch of about 0.5 diopters or less. In some other embodiments, the accommodation-vergence-divergence mismatch of images provided by the display system is about 0.33 diopters or less. In still other embodiments, the accommodation-vergence-divergence mismatch of images provided by the display system is about 0.25 diopters or less, including about 0.1 diopters or less.

[0151] FIG. 5 illustrates aspects of an approach for simulating a three-dimensional image by modifying wavefront divergence. The display system includes a waveguide 270 configured to receive light 770 encoded with image information and output the light to a user's eye 210. The waveguide 270 may output light 650 with a defined amount of wavefront divergence corresponding to the wavefront divergence of a light field generated by a point on a desired depth plane 240. In some embodiments, the same amount of wavefront divergence is provided for all objects presented on that depth plane. In addition, the user's other eye will be illustrated as being provided with image information from a similar waveguide.

[0152] In some embodiments, a single waveguide may be configured to output light with a set wavefront divergence corresponding to a single or limited number of depth planes, and / or the waveguide may be configured to output light of a limited range of wavelengths. As a result, in some embodiments, multiple or stacked waveguides may be utilized to provide different wavefront divergences for different depth planes and / or to output light of different ranges of wavelengths. It should be understood that, as used herein, a depth plane may be a plane or may follow the contour of a curved surface.

[0153] 6 illustrates an example of a waveguide stack for outputting image information to a user. Display system 250 includes a stack of waveguides or stacked waveguide assembly 260 that can be utilized to provide a three-dimensional perception to the eye / brain using multiple waveguides 270, 280, 290, 300, 310. It should be understood that display system 250 may be considered a light field display in some embodiments. Additionally, waveguide assembly 260 may also be referred to as an eyepiece.

[0154] In some embodiments, display system 250 may be configured to provide a substantially continuous cue for convergence and multiple discrete cues for accommodation. The cues for convergence may be provided by displaying different images to each of the user's eyes, and the cues for accommodation may be provided by outputting light that forms images with selectable discrete amounts of wavefront divergence. In other words, display system 250 may be configured to output light with variable levels of wavefront divergence. In some embodiments, each discrete level of wavefront divergence corresponds to a particular depth plane and may be provided by a particular one of waveguides 270, 280, 290, 300, and 310.

[0155] Continuing with reference to FIG. 6 , the waveguide assembly 260 may also include multiple 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 multiple lenses 320, 330, 340, 350 may be configured to transmit image information to the eye using various levels of wavefront curvature or ray divergence. Each waveguide level may be associated with a particular depth plane and configured to output image information corresponding to that depth plane. The image injection devices 360, 370, 380, 390, 400 may act as light sources for the waveguides and may be utilized to inject image information into the waveguides 270, 280, 290, 300, 310, each configured to disperse incident light across each individual waveguide for output toward the eye 210, as described herein. Light exits output surfaces 410, 420, 430, 440, 450 of the image injection devices 360, 370, 380, 390, 400 and is injected into corresponding input surfaces 460, 470, 480, 490, 500 of the waveguides 270, 280, 290, 300, 310. In some embodiments, each input surface 460, 470, 480, 490, 500 may be an edge of the corresponding waveguide or may be a portion of a 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 toward 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.

[0156] 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 via one or more optical conduits (such as fiber optic cables) to each of the image input devices 360, 370, 380, 390, 400. 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).

[0157] In some embodiments, 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 vary the perceived intensity of the light injected into the waveguides 270, 280, 290, 300, 310 and encode the light with image information. Examples of spatial light modulators include liquid crystal displays (LCDs), including liquid crystal on silicon (LCOS) displays. It should be understood that image injection devices 360, 370, 380, 390, 400 are illustrated diagrammatically, and in some embodiments, these image injection devices may represent different light paths and locations within a common projection system configured to output light into associated ones of waveguides 270, 280, 290, 300, 310. In some embodiments, the waveguides of waveguide assembly 260 may function as ideal lenses, relaying light injected into the waveguides to the user's eye. In this concept, the object may be a spatial light modulator 540, and the image may be an image on a depth plane.

[0158] 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 diagrammatically represent 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 diagrammatically represent multiple scanning fibers or multiple bundles of scanning fibers, each configured to inject light into an associated one of the waveguides 270, 280, 290, 300, 310. It should be understood that one or more optical fibers may be configured to transmit light from the optical module 530 to one or more waveguides 270, 280, 290, 300, 310. It should be understood that one or more intervening optical structures may be provided between the scanning fiber or fibers and one or more waveguides 270, 280, 290, 300, 310, for example, to redirect light exiting the scanning fiber into one or more waveguides 270, 280, 290, 300, 310.

[0159] Controller 560 controls the operation of one or more of stacked waveguide assemblies 260, including the operation of image input devices 360, 370, 380, 390, 400, light source 530, and light modulator 540. In some embodiments, controller 560 is part of local data processing module 140. Controller 560 contains programming (e.g., instructions in a non-transitory medium) that coordinates the timing and provisioning of image information to 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. Controller 560 may, in some embodiments, be part of processing module 140 or 150 (FIG. 2).

[0160] Continuing with reference to FIG. 6 , the waveguides 270, 280, 290, 300, and 310 may be configured to propagate light within each individual waveguide by total internal reflection (TIR). Each of the waveguides 270, 280, 290, 300, and 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, the waveguides 270, 280, 290, 300, and 310 may each include outcoupling optical elements 570, 580, 590, 600, and 610 configured to extract light from the waveguides by redirecting the light, causing it 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 outcoupling light, and the outcoupling optical element light may also be referred to as a light extraction optical element. The extracted beam of light may be output by the waveguide at a location where light propagating within the waveguide strikes the light extraction optical element. The outcoupling optical element 570, 580, 590, 600, 610 may be, for example, a grating including diffractive optical features as discussed further herein. While shown disposed on the bottom major surface of the waveguides 270, 280, 290, 300, 310 for ease of explanation and clarity of the drawings, in some embodiments, the outcoupling optical element 570, 580, 590, 600, 610 may be disposed on the top and / or bottom major surfaces and / or directly within the volume of the waveguides 270, 280, 290, 300, 310, as discussed further herein. In some embodiments, the outcoupling optical elements 570, 580, 590, 600, 610 may be formed within a layer of material attached to a transparent substrate and forming the waveguides 270, 280, 290, 300, 310. In some other embodiments, the waveguides 270, 280, 290, 300, 310 may be monolithic material components, and the outcoupling optical elements 570, 580, 590, 600, 610 may be formed on and / or within the material surfaces of the components.

[0161] Continuing with 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 reaching the eye 210. Such first lens 350 may be configured to generate a slight convex wavefront curvature so that the eye / brain interprets light emerging from the next upper waveguide 280 as emerging 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 power of the first lens 350 and the second lens 340 may be configured to produce another, increasing amount of wavefront curvature such that the eye / brain interprets the light emerging from the third waveguide 290 as originating 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.

[0162] 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 a collective focal power representing the focal plane closest to the person. To compensate for 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 collective power of the lower lens stacks 320, 330, 340, 350. Such a configuration provides as many perceived focal planes as there are available waveguide / lens pairs. Both the waveguide outcoupling optical elements and the focusing sides of the lenses may be static (i.e., not dynamic or electro-active). In some alternative embodiments, one or both may be dynamic using electro-active features.

[0163] 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 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.

[0164] Continuing with reference to FIG. 6 , the outcoupling optical elements 570, 580, 590, 600, 610 may be configured for a particular depth plane associated with a waveguide to redirect light from that individual waveguide and output the light with an appropriate amount of divergence or collimation. 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 (eg, cladding layers and / or structures for forming air gaps).

[0165] In some embodiments, the outcoupling optical elements 570, 580, 590, 600, 610 are diffractive features or "diffractive optical elements" (also referred to herein as "DOEs") that form a diffraction pattern. Preferably, the DOEs have a sufficiently low diffraction efficiency so 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 output beams that exit the waveguide at various locations, resulting in a very uniform pattern of output emission toward the eye 210 for this particular collimated beam bouncing within the waveguide.

[0166] 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).

[0167] 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. 9D) and may be in electrical communication with processing modules 140 and / or 150, which may process image information from the camera assembly 630. In some embodiments, one camera assembly 630 may be utilized per eye, monitoring each eye separately.

[0168] 7, an example of an output beam output by a waveguide is shown. While one waveguide is illustrated, it should be understood that other waveguides in waveguide assembly 260 (FIG. 6) may function similarly, and that waveguide assembly 260 includes multiple waveguides. Light 640 is launched into waveguide 270 at input surface 460 of waveguide 270 and propagates within waveguide 270 by TIR. At the point where light 640 impinges on DOE 570, a portion of the light exits the waveguide as output beam 650. Output beam 650 is illustrated as being approximately parallel, but may be redirected to propagate to eye 210 at an angle (e.g., forming a diverging output beam), as discussed herein and depending on the depth plane associated with waveguide 270. It should be understood that a nearly collimated exit beam may refer to a waveguide with outcoupling optics that outcouples 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 waveguides or other sets of outcoupling 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.

[0169] In some embodiments, a full-color image may be formed at each depth plane by overlaying an image in each of the primary colors, for example, three or more primary colors. FIG. 8 illustrates an example of a stacked waveguide assembly, with each depth plane including an image formed using multiple different primary colors. The illustrated embodiment shows depth planes 240a-240f, but more or fewer depths are also contemplated. Each depth plane may have three or more primary color images associated with it, including a first image in a first color G, a second image in a second color R, and a third image in a third color B. Different depth planes are indicated in the diagram by different numbers for diopters (dpt) following the letters G, R, and B. By way of example only, the number following each of these letters indicates the diopter (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 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 corresponding to different distances from the user. Such an arrangement may increase visual acuity and user comfort and / or reduce chromatic aberrations.

[0170] In some embodiments, light for 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 diagram containing the letter G, R, or B may be understood to represent an individual waveguide, and three waveguides may be provided per depth plane, resulting in three primary color images per depth plane. While the waveguides associated with each depth plane are shown adjacent to each other in this drawing for ease of illustration, 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.

[0171] 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 replace one or more of red, green, or blue.

[0172] It should be understood that references to a given color of light throughout this disclosure will be understood to encompass light of one or more wavelengths within the range of wavelengths of light that are perceived by a viewer to be of that given color. For example, red light may include one or more wavelengths of light within a range of about 620-780 nm, green light may include one or more wavelengths of light within a range of about 492-577 nm, and blue light may include one or more wavelengths of light within a range of about 435-493 nm.

[0173] In some embodiments, 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, e.g., infrared and / or ultraviolet wavelengths. Additionally, the waveguide incoupling, outcoupling, and other light redirecting structures of display 250 may be configured to direct and emit this light from the display toward the user's eye 210, e.g., for imaging and / or user stimulation applications.

[0174] Referring now to FIG. 9A , in some embodiments, light impinging on a waveguide may need to be redirected to incoupling the light into the waveguide. An incoupling optical element may be used to redirect and incoupling 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 incoupling optical element. The waveguides may each be configured to output light of one or more different wavelengths or one or more different wavelength ranges. Stack 660 may correspond to stack 260 ( FIG. 6 ), and the illustrated waveguides of stack 660 may correspond to a portion of multiple waveguides 270, 280, 290, 300, 310, although it should be understood that light from one or more of image injection devices 360, 370, 380, 390, 400 is injected into the waveguide from a location requiring the light to be redirected for incoupling.

[0175] The illustrated set 660 of stacked waveguides includes waveguides 670, 680, and 690. Each waveguide includes an associated internal coupling optical element (which may also be referred to as the light input area on the waveguide), for example, internal coupling optical element 700 is disposed on a major surface (e.g., the top major surface) of waveguide 670, internal coupling optical element 710 is disposed on a major surface (e.g., the top major surface) of waveguide 680, and internal coupling 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 internal coupling optical elements 700, 710, 720 may be disposed on the bottom major surface of an individual waveguide 670, 680, 690 (particularly, one or more internal coupling optical elements are reflective polarizing optical elements). As shown, the internal coupling 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 internal coupling optical elements are transmissive turning optical elements. In some embodiments, the internal coupling 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 internal coupling 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. While illustrated on one side or corner of the respective waveguide 670, 680, 690, it should be understood that the internal coupling optical elements 700, 710, 720 may be disposed within other areas of the respective waveguide 670, 680, 690 in some embodiments.

[0176] 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 a different image input device 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 substantially not receive light from others of the in-coupling optical elements 700, 710, 720.

[0177] 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 associated waveguides 670, 680, 690, respectively. In some other embodiments, optically dispersive elements 730, 740, 750 may be disposed on both the top and bottom major surfaces of associated waveguides 670, 680, 690, respectively, or 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.

[0178] 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 waveguides 670 and 680, and layer 760b may separate 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 immediately adjacent 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 than the refractive index of the material forming waveguides 670, 680, 690. Advantageously, the lower refractive index layers 760a, 760b may function 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.

[0179] Preferably, for ease of manufacturing and other considerations, the materials forming waveguides 670, 680, 690 are similar or the same, and the materials forming layers 760a, 760b are similar or the same. In some embodiments, the materials forming waveguides 670, 680, 690 may differ between one or more waveguides, and / or the materials forming layers 760a, 760b may differ while still maintaining the various refractive index relationships discussed above.

[0180] 9A, light rays 770, 780, 790 enter 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).

[0181] In some embodiments, light rays 770, 780, 790 have different properties, e.g., different wavelengths or different wavelength ranges, which may correspond to different colors. Each of the incoupling optical elements 700, 710, 720 deflects incident light such that the light propagates through a respective one of the waveguides 670, 680, 690 by TIR. In some embodiments, each of the incoupling optical elements 700, 710, 720 selectively deflects one or more particular wavelengths of light while transmitting other wavelengths to the underlying waveguide and associated incoupling optical element.

[0182] For example, in-coupling optical element 700 may be configured to selectively deflect light ray 770 having a first wavelength or wavelength range while transmitting light rays 780 and 790 having different second and third wavelengths or wavelength ranges, respectively. Transmitted light ray 780 impinges on and is deflected by in-coupling optical element 710, which is configured to deflect light of the second wavelength or wavelength range. Light ray 790 is deflected by in-coupling optical element 720, which is configured to selectively deflect light of the third wavelength or wavelength range.

[0183] 9A , the deflected light rays 770, 780, 790 are deflected to propagate through the corresponding waveguides 670, 680, 690. That is, the in-coupling optical element 700, 710, 720 of each waveguide deflects the light into its corresponding waveguide 670, 680, 690, in-coupling the light into the corresponding waveguide. The light rays 770, 780, 790 are deflected at an angle that causes the light to propagate through the respective waveguides 670, 680, 690 by TIR. The light rays 770, 780, 790 propagate through the respective waveguides 670, 680, 690 by TIR until they impinge on the waveguide's corresponding optical dispersive element 730, 740, 750.

[0184] 9B, a perspective view of the multiple stacked waveguide embodiment of FIG. 9A is illustrated. As previously described, in-coupled light rays 770, 780, 790 are deflected by in-coupling optical elements 700, 710, 720, respectively, and then propagate by TIR within waveguides 670, 680, 690, respectively. Light rays 770, 780, 790 then impinge on optically dispersive elements 730, 740, 750, respectively. Optically dispersive elements 730, 740, 750 deflect light rays 770, 780, 790 to propagate toward out-coupling optical elements 800, 810, 820, respectively.

[0185] In some embodiments, the optically dispersive elements 730, 740, 750 are orthogonal pupil expanders (OPEs). In some embodiments, the OPEs deflect or disperse light into the out-coupling optical elements 800, 810, 820, and in some embodiments, may also increase the beam or spot size of this light as it propagates into the out-coupling optical elements. In some embodiments, the optically dispersive elements 730, 740, 750 may be omitted, and the in-coupling optical elements 700, 710, 720 may be configured to deflect light directly into the out-coupling optical elements 800, 810, 820. For example, with reference to FIG. 9A , the optically dispersive elements 730, 740, 750 may be replaced with the out-coupling optical elements 800, 810, 820, respectively. In some embodiments, the outcoupling optical elements 800, 810, 820 are exit pupils (EPs) or exit pupil expanders (EPEs) that direct light toward the viewer's eye 210 ( FIG. 7 ). It should be understood that an OPE may be configured to increase the size of the eyebox in at least one axis, and that the EPE may increase the eyebox in an axis that intersects the axis of the OPE, e.g., orthogonal to the axis of the OPE. For example, each OPE may be configured to redirect a portion of the light striking the OPE to an EPE of the same waveguide, while allowing the remaining portion of the light to continue propagating down the waveguide. Upon striking the OPE, again, another portion of the remaining light is redirected to the EPE, and the remainder of that portion continues to propagate further down the waveguide, etc. Similarly, upon striking the EPE, a portion of the impinging light is directed out of the waveguide toward the user, and the remaining portion of that light continues to propagate through the waveguide until it again strikes an EP, at which point another portion of the impinging light is directed out of the waveguide, etc. As a result, a single beam of internally coupled light may be "replicated" each time a portion of that light is redirected by an OPE or EPE, thereby forming a cloned beam field of light, as shown in Figure 6. In some embodiments, the OPE and / or EPE may be configured to modify the size of the beam of light.

[0186] 9A and 9B, in some embodiments, a waveguide set 660 includes, for each primary color, waveguides 670, 680, 690, in-coupling optical elements 700, 710, 720, optically dispersive elements (e.g., OPEs) 730, 740, 750, and out-coupling optical elements (e.g., EPs) 800, 810, 820. The waveguides 670, 680, 690 may be stacked with an air gap / cladding layer between each one. The in-coupling optical elements 700, 710, 720 redirect or deflect incident light into that 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 individual waveguides 670, 680, 690. In the example shown, light ray 770 (e.g., blue light) is deflected by the first in-coupling optical element 700 in the manner described above, then continues bouncing down the waveguide, interacting with the optically dispersive element (e.g., OPE) 730 and then the out-coupling optical element (e.g., EP) 800. Light rays 780 and 790 (e.g., green and red light, respectively) pass through the waveguide 670, with light ray 780 impinging on and being deflected by the in-coupling optical element 710. Light ray 780 will then, via TIR, bounce down the waveguide 680, to its optically dispersive element (e.g., OPE) 740 and then the out-coupling optical element (e.g., EP) 810. Finally, light ray 790 (e.g., red light) passes through the waveguide 690 and impinges on the optically in-coupling optical element 720 of the waveguide 690. The light in-coupling optical element 720 deflects the light ray 790 so that it propagates by TIR to the light dispersive element (e.g., OPE) 750 and then by TIR to the out-coupling optical element (e.g., EP) 820. The out-coupling optical element 820 then finally out-couples the light ray 790 to a viewer, who also receives the out-coupled light from the other waveguides 670, 680.

[0187] FIG. 9C illustrates a top-down plan view of an example of the multiple stacked waveguides of FIGS. 9A and 9B. As shown, waveguides 670, 680, 690 may be vertically aligned, along with each waveguide's associated optically dispersive elements 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., laterally spaced apart, as seen in the top-down view). As discussed further herein, this non-overlapping spatial arrangement facilitates the injection of light from different sources into different waveguides 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, spatially separated in-coupling optical elements may be referred to as shifted-pupil systems, and the in-coupling optical elements in these arrays may correspond to sub-pupils.

[0188] 9D illustrates an example of a wearable display system 60 into which the various waveguide and associated systems disclosed herein may be integrated. In some embodiments, the display system 60 is the system 250 of FIG. 6, which diagrammatically illustrates some portions of the system 60 in greater detail. For example, the waveguide assembly 260 of FIG. 6 may be part of the display 70.

[0189] Continuing with reference to FIG. 9D , 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 directly in front of the user's 90's eye. The display 70, in some embodiments, may be considered an eyepiece. In some embodiments, a speaker 100 is coupled to frame 80 and configured to be positioned adjacent to the user's 90 ear canal (in some embodiments, another speaker, not shown, may optionally be positioned adjacent the user's other ear canal to provide stereo / shapeable sound control). Display system 60 may also include one or more microphones 110 or other devices to detect sound. In some embodiments, the microphones are configured to allow a user to provide input or commands to 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 mounted on the body of the user 90 (e.g., 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.

[0190] 9D , display 70 is operably coupled to local data processing module 140 by a communication link 130, such as wired or wireless connectivity, which may be mounted in a variety of configurations, such as fixedly attached to frame 80, fixedly attached to a helmet or hat worn by the user, embedded within headphones, or otherwise removably attached to user 90 (e.g., in a backpack-style configuration, in a belt-linked configuration). Similarly, sensor 120a may be operably coupled to local processor and data module 140 by a communication link 120b, such as wired or wireless connectivity. Local processing and data module 140 may comprise a hardware processor and digital memory, such as non-volatile memory (e.g., flash memory or a hard disk drive), both of which may be utilized to aid in processing, caching, and storing data. Optionally, local processing and data module 140 may include one or more central processing units (CPUs), graphics processing units (GPUs), dedicated processing hardware, etc. The data may include a) data captured from sensors (such as image capture devices (cameras, etc.), microphones, inertial measurement units, accelerometers, compasses, GPS units, wireless devices, gyroscopes, and / or other sensors disclosed herein (e.g., which may be operatively coupled to frame 80 or otherwise attached to user 90)) and / or b) data obtained and / or processed using remote processing module 150 and / or remote data repository 160 (including data related to virtual content), possibly for passage to display 70 after processing or retrieval. Local processing and data module 140 may be operatively coupled to remote processing module 150 and 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 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 on frame 80 or may be a freestanding structure that communicates with local processing and data module 140 by a wired or wireless communication path.

[0191] 9D , in some embodiments, remote processing module 150 may comprise one or more processors configured to analyze and process data and / or image information, and may include, for example, one or more central processing units (CPUs), graphics processing units (GPUs), dedicated processing hardware, etc. In some embodiments, remote data repository 160 may comprise digital data storage facilities that 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, which provide information, for example, information for generating augmented reality content, to local processing and data module 140 and / or remote processing module 150. In some embodiments, all data is stored and all computations are performed within the local processing and data module, allowing for fully autonomous use from the remote module. Optionally, an external system (e.g., one or more processors, one or more computer systems), including a CPU, GPU, etc., may perform at least a portion of the processing (e.g., generating image information, processing data) and provide information to and receive information from modules 140, 150, 160, e.g., via a wireless or wired connection. illumination

[0192] In some instances, it may be useful to provide illumination, for example, to the eyes. For example, it may be beneficial to project light onto the user's eyes for eye tracking. Eye tracking, in some implementations, may be accomplished by imaging the user's eyes with one or more cameras. Eye illumination may aid such imaging and eye tracking. Having a localized light source, such as a point source, and knowing the location of that light source may also aid in performing eye tracking algorithms. The location of the illumination origin may be the location of a real light source, or the location of a virtual light source from which the illumination appears to occur. Knowledge of such location can, in some approaches, be taken into account when processing the eye tracking algorithm. These illumination sources may, in some implementations, comprise localized light sources, such as point sources. Using multiple illumination sources (and knowing their locations), separated by distances from each other and therefore at different / distinctly different locations, may also aid in processing the eye tracking algorithm. Thus, in some designs, a first illumination source directs light to a user's eye at a first time while a first image is acquired from the eye tracking camera, and a second illumination source directs light to the user's eye at a second time while a second image is acquired from the eye tracking camera. In some implementations, the second light illumination may not illuminate the eye when the first image is acquired, while the first light illumination may not illuminate the eye when the second image is acquired. This process may be referred to herein as multiplexing and may be beneficial in implementing eye tracking algorithms.

[0193] Additionally, the ability to project light onto a user's eye from one or more locations in front of the eye that are more central (as opposed to from a location in the periphery) may also be useful in some cases. In various embodiments disclosed herein (e.g., FIGS. 10A-10D ), multiple light beams are projected generally from in front of the user's eye (e.g., from a more central and less peripheral location) using a light guiding component positioned directly in front of the user's eye. The light guiding component may be optically transparent to visible light so that the user can see through the light guiding component positioned directly in front of the eye and view the environment in front of the user and objects therein. As discussed herein, the light guiding optical component may be configured to emit light guided therein out of the light guiding optical component to provide illumination, for example, to direct light toward the user's eye, and to assist with eye tracking.

[0194] In various situations, the light-guiding optical component is in front of the eye, and the environment with the object therein is in front of the light-guiding optical component. As a result, the terms "in front of" and "in front of" may be used herein to describe locations that are more distal to the eye. Conversely, "behind" and "back of" may be used herein to describe locations that are more proximal to the eye.

[0195] 10A-10D illustrate perspective views of a head-mounted display system configured to project light from an illumination source onto a user's eye. FIG. 10A illustrates a light guiding component 902 for guiding light therein and providing illumination, for example, to the eye (e.g., for eye tracking). An internal coupling element 908 is positioned to couple light from the illumination source into the light guiding component. The light guiding component 902 is shown positioned in front of the eye 916. In various implementations, the light guiding component is optically transparent to visible light so that a user can see through the light guiding component positioned in front of the user's eye. The light guiding component may also include a material having a refractive index such that light from the illumination source can be guided therein.

[0196] In some designs, the light directing component may comprise an eyepiece for presenting an image from the display to the user's eye, as discussed above. The eyepiece may comprise a waveguide for directing light from the display within the waveguide, for example, by total internal reflection. Similarly, the eyepiece for transmitting an image from the display to the user's eye may be used as a conduit for providing light from an illumination source to the eye, for example, for its illumination (e.g., for eye tracking).

[0197] The light guiding component includes an out-coupling optical element 912 configured to eject light guided within the light guiding component out of the light guiding component. In some designs, the light guiding component and the out-coupling optical element are positioned relative to a user's eye to direct light from the illumination source onto the user's eye. If the light guiding optical component also includes an eyepiece for presenting image content to the user's eye, the out-coupling optical element may include, for example, an exit pupil expander 912 as described above. The light distributing optical element 910 may be used to redirect light guided within the light guiding component 902 so that the light exits from a specific location on the light guiding optical element. If the light guiding optical component also includes an eyepiece for presenting image content to the user's eye, the light distributing optical element may include, for example, an orthogonal pupil expander 910 as described above. The light directing component 902, the light distributing element (OPE) 910, and the outcoupling optical element (OPE) 912 may be configured to operate in a manner similar to the waveguides 670, 680, 690 shown in Figures 9A-9C. Similarly, in various implementations, the light distributing element and the outcoupling optical element may comprise a diffractive optical element, such as a diffraction grating or a hologram or both or other diffractive optical element.

[0198] Similarly, the light guiding component may comprise, for example, one or more of the waveguides 670, 680, 690 shown in Figures 9A-9C, or alternatively, the eyepiece may be used as the light guiding component to provide illumination to the eye in addition to providing display content. However, in some other implementations, the light guiding component comprises an additional light guiding component to any waveguide or waveguides used to convey image content to the user's eye, such as the waveguides 670, 680, 690 shown in Figures 9A-9C.

[0199] 10A-10D, one or more illumination sources are coupled into the light directing component 902 and emit therefrom to provide illumination, e.g., light that illuminates a user's eye. In some designs, the illumination sources may comprise invisible or visible light sources, such as infrared or visible light sources, configured to selectively emit IR or visible wavelength light, respectively. The illumination sources may comprise, for example, LEDs or lasers or other types of emitters or light sources. In some designs, the illumination sources comprise vertical cavity surface emitting lasers (VCSELs). In some implementations, filters may be included to provide spectral narrowing. The filters may comprise, for example, narrow bandpass filters in some cases.

[0200] In some implementations, the illumination source may comprise an emitter that outputs a diverging beam. In some such cases, additional collimating optics may increase the collimation of the light from the illumination source.

[0201] 10A-10D , the internal coupling element 908 comprises an internal coupling prism or other reflective coupling element. In some implementations, the internal coupling element is configured to internally couple light from at least one illumination source into the light guiding component at an angle greater than the critical angle of the light guiding component. In some embodiments, the internal coupling element is configured to internally couple light from at least one illumination source into the light guiding component at an angle of approximately 45°. A prism having an angled reflective surface (e.g., providing reflection via total internal reflection) may be suitable for redirecting light from the illumination source into the light guiding component at 45° relative to the light guiding component (e.g., relative to the main top and bottom or front and back reflective surfaces of the light guiding component, which direct the light within the light guiding component via total internal reflection). If light propagates within a light guiding component (such as a planar light guiding plate, sheet, or film) at a 45° angle relative to the light guiding component (e.g., relative to the main top and bottom or front and back reflective surfaces of the light guiding component) and is not redirected out of the light guiding component, the light may reflect off the edge of the light coupling component and continue to be guided therein in the opposite direction via total internal reflection. In some implementations, the internal coupling optical element may comprise an internal coupling grating (ICG) or other diffractive optical element. In some designs, more than one internal coupling element may be employed.

[0202] In some designs, the one or more illumination sources comprise multiple illumination sources producing multiple beams of light. In some implementations, the illumination sources emit light of a different color than the others of the illumination sources, and the illumination sources may include multiple filters, with each different filter producing a light beam of a different wavelength. Any number of illumination sources may be utilized, such as 1, 2, 3, 4, 5, 10, or 20 illumination sources, or any range between any of these values. In some implementations, the multiple light beams have distinct spectral compositions or colors or wavelength bands.

[0203] 10A-10D show three illumination sources 904A, 904B, and 904C, a single collimating lens 906 configured to couple light into an in-coupling optical element 908 (e.g., a prism), and an out-coupling optical element configured to out-couple light from the light directing component 902 to a user's eye 916. In various implementations (see, e.g., FIG. 10B ), light can be out-coupled from the out-coupling optical element 912 such that the out-coupled light appears to originate from one or more virtual sources 992A, such as point sources. The light may diverge upon exiting the light directing component, for example, such that the light appears to emanate from a virtual source, such as a localized source (e.g., a point source) located a distance away from (e.g., in front of) the light directing optical element.

[0204] 10B-10D each illustrate such a system in operation, displaying light 926A, 926B, and 926C from light sources 904A, 904B, and 904C coupled into a light directing component 902 and outcoupled into an eye 916 in different directions as if emanating from differently spatially located localized virtual sources 922A, 922B, and 922C at a particular depth (e.g., depth plane 914). FIG. 10B illustrates a first illumination source 904A emitting a diverging beam of light 920A that is coupled into the light directing component 902, e.g., via a prism 908. A collimating lens 906 in the optical path between the illumination source 904A and the in-coupling element 908 collimates the light so that it propagates substantially along a common direction. Light from a first illumination source 920A propagates within light directing component 902 and is redirected by a light distribution element (e.g., OPE) 910 toward an out-coupling optical element 912 (e.g., EPE). The out-coupling optical element ejects the light guided within light directing component 902 toward a user's eye 916. The light exiting light directing component 902 constitutes a diverging beam that appears to emanate from a first virtual light source 922A at a depth plane 914. The direction in which the diverging beam is directed causes the first virtual light source 922A to appear to be located at a particular location on the depth plane 914, for example. Thus, the outcoupled light 926A is directed toward the user's eye 916 as if the outcoupled light 926A were emitted from a first virtual source 922A originating from the depth plane 914, and the virtual light 924A is a virtual projection of the outcoupled light 926A between the light guiding component 902 and the depth plane 914.

[0205] 10C illustrates a second illumination source 904B emitting a diverging beam of light 920B that is coupled into the light guiding component 902 via a prism 908. A collimating lens 906 in the optical path between the second illumination source 904B and the internal coupling element 908 collimates the light so that the light propagates substantially along a common direction. The light from the second light source 920B propagates within the light guiding component 902 and is redirected by a light distribution element (e.g., an OPE) 910 toward an external coupling optical element 912 (e.g., an EPE). The external coupling optical element ejects the light guided within the light guiding component 902 toward the user's eye 916. The light exiting the light guiding component 902 constitutes a diverging beam that appears to emanate from a second virtual light source 922B at the depth plane 914. The direction in which the diverging beam is directed causes a second virtual light source 922B to appear to be located, for example, at a particular location on the depth plane 914. Thus, outcoupled light 926B is directed to the eye 916 as if the outcoupled light 926B were emanating from a second virtual source 922B originating from the depth plane 914, and virtual light 924B is a virtual projection of the outcoupled light 926B between the light coupling component 902 and the depth plane 914.

[0206] 10D illustrates a third illumination source 904C emitting a diverging beam of light 920C that is coupled into the light guiding component 902 via a prism 908. A collimating lens 906 in the optical path between the third illumination source 904C and the internal coupling element 908 collimates the light so that the light propagates substantially along a common direction. The light from the third illumination source 920C propagates within the light guiding component 902 and is redirected by a light distribution element (e.g., an OPE) 910 toward an external coupling optical element 912 (e.g., an EPE). The external coupling optical element ejects the light guided within the light guiding component 902 toward the user's eye 916. The light exiting the light guiding component 902 constitutes a diverging beam that appears to emanate from a third virtual light source 922C at the depth plane 914. The direction in which the diverging beam is directed causes a third virtual light source 922C to appear to be located, for example, at a particular location on the depth plane 914. Thus, outcoupled light 926C is directed to the eye 916 as if the outcoupled light 926C were emanating from a third virtual source 922C originating from the depth plane 914, and virtual light 924C is a virtual projection of the outcoupled light 926C between the light coupling component 902 and the depth plane 914.

[0207] In various implementations, the out-coupling optical element comprises a diffractive optical element, such as a grating structure or a hologram or other diffractive optical element, configured to redirect light guided within the light guiding component out of the light guiding component so that the light is not guided within the light guiding optical component. In various implementations, the out-coupling optical element may be formed on both sides of the light guiding component and / or within the light guiding component. The out-coupling optical element may comprise, for example, one or more volume holograms, surface holograms, volume or surface diffractive optical elements, and / or diffraction gratings. The diffractive optical element (e.g., a grating or hologram) can be configured to diverge light exiting the light guiding component, causing the light to appear as if it originated from a different location, for example, in front of the light guiding component. Thus, the out-coupling optical element may be considered to have a refractive power, such as a negative refractive power, to diverge light incident thereon as if it originated from a different location or depth. Thus, in some cases, the outcoupling optical element may comprise a diffraction grating or diffractive optical element (e.g., a hologram) with refractive power, e.g., negative refractive power. The addition of other types of outcoupling optical elements or additional optical elements such as lenses or lens arrays may be used to impart refractive power and, for example, diverge the light as if it were emanating from a virtual light source located in front of (or behind) the light directing component.

[0208] As discussed above, a head-mounted display system may include a waveguide configured to receive light from one or more displays and direct the light to a user's eyes to provide image content to a user. Optical power may be provided in an optical element (e.g., an outcoupling optical element or EPE) to diverge light exiting the waveguide as if it originates from a different depth plane. Such a system (e.g., a waveguide) used to direct light from a display into a user's eyes and provide image content to a user may also be used to direct illumination from an illumination source (e.g., to a user's eyes). A similar structure (e.g., an outcoupling optical element or EPE) configured to diverge light from a display may also be used to diverge light from an illumination source as if it originates from a virtual light source (e.g., a point source) located at a distance away from the light-coupling component. In such a configuration, the light-directing optical element may receive light from both one or more displays and one or more illumination sources via one or more incoupling optical elements. In some implementations, a single outcoupling optical element (e.g., EPE) is used to outcouple light from a light guiding component or waveguide. This outcoupling optical element may, in some implementations, comprise a diffractive optical element, such as a hologram, and / or may further be integrated with one or more lenses to provide negative (or positive) optical power. In other implementations, a light guiding component may be provided in addition to an eyepiece or other waveguide to transmit light from one or more displays to a user's eye. In some implementations, the outcoupling optical element may be diffusive. The outcoupling optical element may comprise, for example, a holographic diffuser.

[0209] As illustrated in FIGS. 10B-10D , virtual sources from which light appears to emanate may be located at different positions along a single virtual depth plane. Thus, multiple virtual sources may arise from a single virtual depth plane. Conversely, multiple virtual sources may arise from multiple virtual depth planes. In some designs, the virtual source may be a localized source of emission, such as a virtual point source. In some implementations, the virtual source may have a maximum lateral extent of about 100 nm, 250 nm, 500 nm, about 1 μm, about 2 μm, about 3 μm, about 5 μm, about 10 μm, or about 50 μm, or any range between any of these values. In some configurations, the virtual depth plane at which the virtual source is located may be about 5 mm, about 10 mm, about 15 mm, about 20 mm, about 30 mm, about 50 mm, about 100 mm, or about 200 mm from the front (or back) of the light-coupling component or the user's eye, or any range between any of these values.

[0210] In various implementations, the outcoupling optical element may produce multiple virtual sources, such as 2, 3, 4, 5, 6, 10, or 20 virtual sources, or any range between any of these values. These virtual sources may be at different locations on the same depth plane, at different depth planes, or a combination of both.

[0211] Thus, the outcoupling optical element may produce outcoupled light in multiple directions. This may depend, for example, on the light source outputting the light. Different light sources having different positions relative to the incoupling optical element may potentially be collimated and directed in different directions within the light guiding component, and therefore provide different beams that are incident on the outcoupling optical element from different directions and potentially at different locations. The result is that the outcoupling beams have different directions. This may give rise to virtual sources from which light appears to originate differently (e.g., have different locations) due to different illumination sources.

[0212] As discussed above, having multiple light sources placed at different known locations can be used for eye tracking, and knowledge of the light source locations aids in executing the eye tracking algorithm. Thus, different illumination sources (and therefore different corresponding virtual sources) may be activated when a camera or sensor (e.g., an eye tracking camera) captures an image. Light may be projected into the eye from different virtual sources at specific lateral positions and / or depths in front of the user's eye at different times when different images of the eye are captured by the camera. Because more light beams with different known virtual source positions and depths are utilized, the light beams may be multiplexed and eye tracking may be improved. Such a time-multiplexing approach may be used in conjunction with an eye tracking camera to increase eye tracking robustness. In some cases, wavelength multiplexing may be used. For example, different illumination sources having different spectral outputs (or transmitted through wavelength filters) and providing different spectral distributions may be used to couple into different outcoupling optical elements designed to selectively affect different wavelengths. Thus, as shown, the system may additionally include an eye tracking camera 918 to capture images of the eye and track the user's eye 916 .

[0213] In some configurations, such as those discussed above, the outcoupling optical element may be configured to direct the outcoupled light toward the user's eye. Such illumination may be provided to the eye, for example, to perform eye tracking. However, in other configurations, the outcoupling optical element may be configured to direct the outcoupled light into an environment in front of the user's eye. Such illumination may be used, for example, to sense the depth of objects in the environment in front of the user. Alternatively, such illumination may be used to provide notification to others of the eyewear's status (e.g., during a video conversation) or for aesthetic effect. Other uses are also possible.

[0214] A wide range of variations are possible. For example, in some implementations, a light distributing optical element (or OPE) may be used, while in other implementations, an OPE may be absent. Similarly, the light distributing optical element (or OPE) may be formed on or within the light directing component, and may comprise a diffractive optical element or other optical structure.

[0215] In some embodiments, the image projector of the head mounted display and the illumination source share the same internal coupling optics and light directing components. mask

[0216] As discussed above, in some instances, such as for eye tracking, it may be beneficial to project light onto a user's eye as if the light originated from multiple light sources. Furthermore, in some instances, for example, for depth sensing, it may be useful to project light from one or more light sources into an environment in front of the user's eye. One or more illumination sources and light directing components may be employed to provide such illumination.

[0217] 11A-11B illustrate perspective views of a light directing component 1002 having a mask with openings configured to produce localized regions from which light emanates. Specifically, FIG. 11A shows the light directing component 1002 having an internal coupling element 1008 positioned to couple light therein. A light distribution element (e.g., an OPE) 1010 and an external coupling optical element 1012 (e.g., an EPE) are disposed on or within the light directing component 1002. Disposed relative to (e.g., over or below) the external coupling element 1012 is a mask 1014 with four mask holes or mask openings 1022A, 1022B, 1022C, 1022D. The light directing component 1002, the light distributing element (OPE) 1010, and the outcoupling optical element (EPE) 1012 may be configured to operate in a manner similar to the waveguides 670, 680, 690 shown in FIGS. 9A-9C and discussed above with respect to FIGS. 10A-10D. For example, in some implementations, one or both of the light distributing element (OPE) 1010 and the outcoupling optical element (EPE) 1012 comprise diffractive optical elements, although the structure of these elements should not be so limited. Furthermore, the outcoupling optical element need not be provided with refractive power or otherwise configured to diverge light emitted from the light directing component 1002 by the outcoupling optical element. As discussed below, openings in a mask may provide such divergence in some implementations. Also, as discussed above, the light directing component 1002 may comprise an eyepiece comprising one or more waveguides (such as waveguides 670, 680, 690 shown in Figures 9A-9C) configured to receive light from the display and deliver image content to the user's eye, or alternatively, the light directing component 1002 may complement such an eyepiece configured to deliver image content to the user.

[0218] 11B shows an illumination source 1004 positioned relative to an in-coupling optical element 1008 to couple light into a light directing component 1002 such that the light is guided therein by total internal reflection. A light distribution element 1010 is positioned to receive the light coupled into the light directing component 1002 by the in-coupling optical element and redirect the light toward the out-coupling optical element. The out-coupling optical element causes the light to exit the light directing component. As discussed above, the out-coupling optical element may comprise a diffractive optical element, diffractive features, scattering features, or otherwise be configured to redirect light guided within the light directing component so that the light is not guided therein. For example, the light may be directed toward a user's eye at an angle such that the light would not be guided within the light directing component by total internal reflection. The mask may include a material that is opaque (e.g., absorptive, reflective) to the light emitted by the illumination source so that the light does not exit the light guide, e.g., toward the eye, unless the light passes through one or more openings 1022A, 1022B, 1022C, 1022D in the mask. In some implementations, the mask may comprise a dielectric, such as a dielectric coating, and may be reflective at a specific wavelength or wavelengths. In some designs, the mask may be more efficient by being more reflective and less absorptive.

[0219] In some configurations, the openings in the mask are small compared to the mask. The reduced size can, in some instances, cause divergence of the beam exiting through the opening due to diffraction. The openings may have a lateral extent, e.g., width or diameter, of, for example, about 1 μm, about 5 μm, about 10 μm, about 20 μm, about 50 μm, about 100 μm, about 500 μm, about 1 mm, or about 5 mm, or any range between any of these values. In some cases, the small openings can be considered to create point light sources. Several such localized light sources, spaced apart from one another, may be created by the openings in the mask.

[0220] FIG. 11B illustrates outcoupled light 1026A, 1026B, 1026C, and 1026D propagating through openings 1022A, 1022B, 1022C, and 1022D, which may be point sources as shown. FIG. 11B particularly depicts illumination source 1004 emitting a diverging light beam 1020 into internal coupling element 1008. Internal coupling element 1008 couples the light into light directing component 1002 such that the light is guided therein by total internal reflection. However, the light beam continues to diverge within the light directing optical element. Light incoupled into light directing component 1002 may propagate to light distribution element or OPE 1010. Light distribution element or OPE 1010 may redirect at least a portion of this light to outcoupling optical element 1012. As discussed above, the out-coupling optical element 1012 is configured to output light from the light directing component 1002. However, if the mask 1014 covers the out-coupling optical element 1012 or a portion of the light directing component 1002 through which light would be output by the out-coupling optical element, the light may be blocked such that little light escapes through the mask. However, the openings 1022A, 1022B, 1022C, 1022D in the mask allow light to pass therethrough. Light 1026A, 1026B, 1026C, 1026D may exit through the openings 1022A, 1022B, 1022C, 1022D, for example, to a user's eyes (or the environment in front of the user).

[0221] An opening can be an area of ​​the mask where the mask is transparent, not necessarily an area devoid of material. For example, the mask may comprise areas that are substantially opaque (reflective and / or absorptive) and areas that are substantially less opaque (e.g., less reflective and / or absorptive). These latter areas are referred to herein as openings in the mask because more light will pass through these areas or openings. In configurations where the mask is reflective, light that is not transmitted through the openings can potentially be reflected back into and guided within the light directing component until it exits, in a process referred to herein as recycling or light recycling.

[0222] In some implementations, the mask may be dichroic and / or wavelength-selective. For example, the mask may absorb or reflect invisible (e.g., infrared) light, thereby blocking and / or recycling light from an illumination source, which may be an infrared light source. However, the openings would be configured to allow this infrared light to pass through. However, the mask may be transparent to visible light so that the user can see through the mask to the environment in front of the user.

[0223] In some embodiments, multiple dichroic masks may be stacked relative to the external coupling element so that light at a first wavelength is blocked or substantially blocked by the first mask but passes through the openings in the first mask (e.g., the first mask blocks a first wavelength or spectral range and the second mask blocks a second wavelength or spectral range). The first wavelength will also be transmitted by the second mask. Similarly, the second wavelength will be blocked or substantially blocked by the second mask but will pass through the openings in the second mask. The second wavelength will also be transmitted by the first mask. As a result, first and second light sources configured to output light corresponding to the first and second wavelength ranges, respectively, are produced. As discussed above, potentially having different, spatially separated light sources at known positions can improve eye tracking. Multiplexing (time multiplexing and / or wavelength multiplexing) may be used to coordinate image capture with the activation of different individual light sources. In some implementations, different ones of the multiple masks may have their own patterns and multiple openings. The multiple masks and opening patterns may be used in conjunction with multiple wavelength sources and / or filters, thereby enabling selective wavelength-based outcoupling of light through selective openings in the multiple masks.

[0224] Thus, the illumination source may emit light at a wide variety of different wavelengths, such as IR and / or visible wavelengths. As discussed above, the illumination source may comprise an LED or a laser. In some implementations, the illumination source comprises a vertical-cavity surface-emitting laser (VCSEL). In some configurations, the illumination source may produce a diverging beam, and / or the diverging beam is coupled into a light-guiding component. In some designs, one or more illumination sources may comprise multiple illumination sources producing multiple beams of light. In some implementations, the multiple light beams have different individual wavelengths. In some configurations, filters, such as narrow bandpass filters, are employed to adjust the wavelength characteristics of the light. In some implementations, the multiple illumination sources include multiple filters, with different filters producing light beams of different wavelengths. Any number of illumination sources may be utilized, such as 1, 2, 3, 4, 5, or 10 illumination sources, or any range between any of these values.

[0225] In some configurations, the internal coupling optical element may comprise an internal coupling grating (ICG). In some configurations, the internal coupling optical element comprises an internal coupling prism. In some implementations, the internal coupling element is configured to internally couple light from the at least one illumination source into the light guiding component at an angle greater than the critical angle of the light guiding component. In some implementations, the internal coupling optical element is configured to internally couple light from the at least one illumination source into the light guiding component at an angle of approximately 45°. A prism having an angled reflective surface (e.g., providing reflection via total internal reflection) may be suitable for redirecting light from the illumination source into the light guiding component at 45° relative to the light guiding component (e.g., relative to the main top and bottom or front and back reflective surfaces of the light guiding component, which guide the light within the light guiding component via total internal reflection). If light propagates within a light guiding component (such as a planar light guide plate, sheet, or film) at a 45° angle relative to the light guiding component (e.g., relative to the main top and bottom or front and back reflective surfaces of the light guiding component) and is not redirected out of the light guiding component, the light may reflect off the edges of the light guiding component and continue to be guided therein in the opposite direction via total internal reflection. More than one internal coupling optical element may be employed.

[0226] In various implementations, the light directing component may include a material that is optically transparent to light from one or more illumination sources. Light may be guided within the light directing component by total internal reflection. However, in some implementations, the light directing component comprises a hollow conduit having an inner sidewall from which light is reflected and guided within the light directing component.

[0227] In some implementations, a light-dispersing optical element or OPE may be formed on or within the light-guiding component. In some configurations, the light-dispersing optical element or OPE may be omitted.

[0228] In some designs, the outcoupling optical element may be formed on or within the light directing component. The outcoupling optical element may comprise one or more diffractive optical elements, such as one or more diffraction gratings and / or holograms. The outcoupling optical element may comprise one or more diffusing or scattering features or layers. For example, the outcoupling optical element may comprise one or more diffuser sheets, one or more light-shaping diffusers, one or more diffuser films, one or more etchings, one or more transmissive optical elements, one or more particles or particle layers, one or more irregular surfaces, one or more surface relief structures, PTFE, Teflon, frosted glass, milk glass, gray glass, one or more white surfaces, colored gels, one or more holograms, or any combination thereof. The outcoupling optical element may direct light guided within the light directing optical element toward the mask and the opening in the mask so that at least a portion of the light may exit through the opening.

[0229] In some implementations, the outcoupling optical element encompasses the entire area of ​​the mask, and / or vice versa. In some implementations, the outcoupling optical element is larger than the mask, or the mask is larger than the outcoupling optical element. In some implementations, the outcoupling optical element encompasses the area of ​​the mask opening.

[0230] In some configurations, the outcoupling optical element may be omitted. For example, light may leak out of the light directing optical element simply by not being totally internally reflected therein. For example, the inner sidewall of the light directing element may be reflective but allow some light guided within the light directing component to pass therethrough. Other variations are also possible.

[0231] As discussed above, in some configurations, light is projected out of the light directing optical element toward the user's eye for tracking, illuminating the user's eye with, for example, infrared light. In some implementations, one or more cameras are used to capture images of the eye illuminated by the illumination source. In some configurations, a time-multiplexing approach may be used in conjunction with the cameras to increase eye tracking robustness.

[0232] In some configurations, light is emitted out from the light directing component towards the environment in front of the user, potentially illuminating objects in the environment and providing depth sensing, for example.

[0233] Thus, one or more eye-tracking cameras, depth sensors, or other components may additionally be included. Likewise, one or more displays for projecting image content into the user's eye may also be included. Similarly, any of the features, structures, variations, applications, uses, advantages, etc. described above may be used in conjunction with or applicable to implementations employing a mask and one or more openings in the mask to provide illumination.

[0234] In some embodiments, the image projector and illumination source of the head mounted display share the same incoupling optics and light directing components. Diffused Optical Elements

[0235] In various implementations, the outcoupling optical element may comprise a diffusing optical element.

[0236] 12A-12B illustrate perspective views of a light directing component 1102, for example, including multiple diffusing optical elements, diffusing regions, or scattering regions for outputting light guided within the light directing component 1102. Specifically, FIG. 12A shows the light directing component 1102 with an internal coupling element 1108 positioned to couple light therein. Disposed on or within the light directing component 1102 are a light distribution element (e.g., OPE) 1110 and an external coupling optical element 1112 (e.g., EPE) comprising multiple diffusing optical elements or scattering regions 1122A, 1122B, 1122C, 1122D (e.g., four diffusing optical elements are shown) for outputting light guided within the light directing component 1102. The light directing component 1102, the light distributing element (OPE) 1110, and the external coupling optical element (EPE) 1112 may be configured to operate in a manner similar to the waveguides 670, 680, 690 shown in FIGS. 9A-9C and discussed above with respect to FIGS. 10A-10D. For example, in some implementations, the light distributing element (OPE) 1110 comprises a diffractive optical element, although the structure of these elements should not be so limited. Also, as discussed above, the light directing component may further comprise an eyepiece comprising one or more waveguides (such as waveguides 670, 680, 690 shown in FIGS. 9A-9C) configured to receive light from the display and deliver image content to the user's eye, or alternatively, the light directing component may complement such an eyepiece configured to deliver image content to the user. However, in some implementations, the light directing component may also comprise an eyepiece used to communicate image content to the user. For example, the light directing component may comprise a waveguide for directing light from an illumination source (e.g., to the user's eye or the environment in front of the user) and for directing light from a projector or display to the user's eye to present an image to the user's eye.In some designs, such as when a light directing component is used to transmit both illumination from an illumination source and light from an image projector or display, both an out-coupling optical element (EPE) 1112 with a diffractive optical element (or a diffractive optical element) and an out-coupling optical element (EPE) for out-coupling light from the display or image projector may be included. In some cases, one or both of the out-coupling optical element (EPE) 1112 with a diffractive optical element (or a diffractive optical element) and / or the out-coupling optical element (EPE) for out-coupling light from the display or image projector are wavelength-selective. For example, the out-coupling optical element (EPE) 1112 with a diffractive optical element (or a diffractive optical element) may be configured to selectively out-couple a first wavelength or group of wavelengths, and the out-coupling optical element (EPE) for out-coupling light from the display or image projector may be configured to selectively out-couple a second wavelength or group of wavelengths. In some such cases, the outcoupling optical element (EPE) 1112 comprising a diffractive optical element (or a diffractive optical element) may be configured to not outcouple light having a second wavelength or group of wavelengths, and the outcoupling optical element (EPE) for outcoupling light from the display or image projector may be configured to not outcouple light having a first wavelength or group of wavelengths. The first wavelength or group of wavelengths may include infrared wavelengths and invisible wavelengths, and the second wavelength or group of wavelengths may include visible wavelengths and not include non-infrared wavelengths. In such cases, for example, the outcoupling optical element (EPE) 1112 comprising a diffractive optical element (or a diffractive optical element) may outcouple infrared and invisible light, while the outcoupling optical element (EPE) for outcoupling light from the display or image projector may outcouple visible light and not outcouple infrared light, or at least infrared light output by the illumination source.Thus, in some designs, the out-coupling optical element 1112 may be wavelength selective, such that, for example, the out-coupling optical element out-couples only select wavelengths (e.g., IR) guided therein and does not interact with or out-couple other wavelengths (e.g., visible) guided therein. Other approaches are also possible. For example, in some implementations, an out-coupling optical element (EPE) for out-coupling light from a display or image projector may have openings or discontinuities corresponding to lateral placement or locations of the out-coupling optical element (EPE) 1112 that comprise a diffractive optical element (or diffractive optical element).

[0237] 12B shows an illumination source 1104 positioned relative to an inward coupling optical element 1108 to couple light into the light guiding component 1102 such that the light is guided therein by total internal reflection. A light distribution element 1210 is positioned to receive light coupled into the light guiding component 1102 by the inward coupling optical element and redirect the light toward an outward coupling optical element comprising a diffusing optical element or scattering region. The outward coupling optical element, i.e., the diffusing optical element or scattering region, causes light from the illumination source to exit the light guiding component 1102. As discussed above, the outward coupling optical element may comprise diffusing or scattering features configured to redirect light guided within the light guiding component 1102 so that the light is not guided therein. For example, the light may be directed toward a user's eye at an angle such that the light would not be guided within the light guiding component 1102 by total internal reflection. Scattering features 1122A, 1122B, 1122C, 1122D may be positioned within a localized region such that light appears to emanate from a localized light source (e.g., a point source) that may be located on or at the surface of the light-guiding component, for example.

[0238] Thus, in some configurations, the diffusing regions 1122A, 1122B, 1122C, 1122D are small compared to the light directing component 1102. The reduced size may, in some instances, cause beam divergence due to diffraction. One of the diffusing regions 1122A, 1122B, 1122C, 1122D may have a lateral extent, e.g., a width or diameter, of, for example, about 1 μm, about 5 μm, about 10 μm, about 20 μm, about 50 μm, about 100 μm, about 500 μm, about 1 mm, or about 5 mm, or any range between any of these values. In some cases, one of the diffusing regions 1122A, 1122B, 1122C, 1122D may be considered to create a point light source. Several such localized light sources spaced apart from one another may be created by a plurality of diffusion regions 1122A, 1122B, 1122C, 1122D.

[0239] 12B illustrates outcoupled light 1126A, 1126B, 1126C, 1126D emitted by diffusing regions 1122A, 1122B, 1122C, 1122D, which may correspond to point sources as shown. FIG. 12B particularly depicts illumination source 1104 emitting diverging light 1020 into in-coupling optical element 1108. In-coupling element 1108 couples the light into light guiding component 1102 such that the light is guided therein by total internal reflection. However, the light beam may continue to diverge within the light guiding optical element. Light in-coupled into light guiding component 1102 may propagate to light distribution element or OPE 1110. The light distribution element or OPE 1010 may redirect at least a portion of this light to the out-coupling optical element 1112 comprising multiple diffusing optical elements or scattering regions 1122A, 1122B, 1122C, 1122D. As discussed above, the out-coupling optical element 1112 comprising multiple diffusing optical elements or scattering regions 1122A, 1122B, 1122C, 1122D is configured to output the light and form the light guiding component 1102. The light 1126A, 1126B, 1126C, 1126D may be output by the diffusing optical elements or scattering regions 1122A, 1122B, 1122C, 1122D, for example, to the user's eye (or the environment in front of the user).

[0240] In some implementations, multiple light beams illuminate multiple outcoupling optical elements comprising multiple diffusing optical elements. For example, in some designs, reflections from opposing edges and / or splitting of the beams direct the beams toward different outcoupling optical elements comprising different diffusing optical elements. In various implementations, for example, different light beams of the multiple light beams comprise different wavelengths of light, and different ones of the multiple outcoupling optical elements selectively outcouple individual ones of these wavelengths, such that different light beams having different wavelengths are outcoupled through different individual outcoupling optical elements. In some designs, these multiple light beams can be redirected or outcoupled simultaneously or sequentially.

[0241] The illumination source may emit light of a wide variety of different wavelengths, such as IR and / or visible wavelengths. As discussed above, the illumination source may comprise an LED or a laser. In some implementations, the illumination source comprises a vertical-cavity surface-emitting laser (VCSEL). In some embodiments, the illumination source may produce a diverging beam, and / or the diverging beam is coupled into a light-guiding component. In some configurations, one or more illumination sources may comprise multiple illumination sources producing multiple beams of light. In some implementations, the multiple light beams have different individual wavelengths. In some configurations, filters, such as narrow band-pass filters, are employed to adjust the wavelength characteristics of the light. In some designs, the multiple illumination sources include multiple filters, with different filters producing light beams of different wavelengths. Any number of illumination sources may be utilized, such as 1, 2, 3, 4, 5, or 10 illumination sources, or any range between any of these values. In some embodiments, the multiple light beams may be redirected simultaneously or sequentially.

[0242] In some configurations, the internal coupling element may comprise an internal coupling grating (ICG). In some configurations, the internal coupling element comprises an internal coupling prism. In some implementations, the internal coupling element is configured to incoupling light from at least one illumination source into the light guiding component at an angle greater than the critical angle of the light guiding component. In some designs, the internal coupling element is configured to incoupling light from at least one illumination source into the light guiding component at an angle of approximately 45°. A prism having an angled reflective surface (e.g., providing reflection via total internal reflection) may be suitable for redirecting light from the illumination source into the light guiding component at 45° relative to the light guiding component (e.g., relative to the main top and bottom or front and back reflective surfaces of the light guiding component, which guide the light within the light guiding component via total internal reflection). If light propagates within a light guiding component (such as a planar light guide plate, sheet, or film) at a 45° angle relative to the light guiding component (e.g., relative to the main top and bottom or front and back reflective surfaces of the light guiding component) and is not redirected out of the light guiding component, the light may reflect off the edge of the light coupling component and continue to be guided therein in the opposite direction via total internal reflection. More than one internal coupling element may be employed.

[0243] In various implementations, the light directing component may include a material that is optically transparent to light from one or more illumination sources. Light may be guided within the light directing component by total internal reflection. However, in some implementations, the light directing component comprises a hollow conduit having an inner sidewall from which light is reflected and guided within the light directing component.

[0244] In some implementations, a light-dispersing optical element or OPE may be formed on or within the light-guiding component. In some configurations, the light-dispersing optical element or OPE may be omitted.

[0245] In some configurations, a majority of the out-coupled light exits the light guiding component, i.e., from the diffusing optical element. In some designs, the diffusing optical element may scatter the light out. In some configurations, the diffusing optical element is refractive, reflective, diffractive, or any combination thereof. In some designs, the out-coupling optical element may be formed on or within the light guiding component. In some designs, for example, the diffusing optical element is disposed on the top surface of the light guiding component. In some implementations, a diffusing optical element, such as a diffusing sheet or film or portion thereof, or a diffusing material or particle, is disposed on the surface of the light guiding component. In some configurations, the diffusing optical element is disposed within the volume of the light guiding component. In some embodiments, the out-coupling optical element may comprise a diffusing optical element. In some embodiments, multiple out-coupling optical elements are employed, comprising multiple diffusing optical elements. In some embodiments, the out-coupling optical element (or multiple diffusing optical elements) each selectively out-couples light from a different spectral region.

[0246] The outcoupling optical element may comprise one or more diffusing or scattering features or layers. For example, the outcoupling optical element may comprise one or more diffuser sheets, one or more light-shaping diffusers, one or more diffuser films, one or more etchings, one or more transmissive optical elements, one or more particles or layers of particles, one or more irregular surfaces, one or more surface relief structures, polytetrafluoroethylene (e.g., PTFE and / or Teflon), frosted glass, milky glass, gray glass, one or more white surfaces, colored gels, one or more holograms, or any combination thereof. In some implementations, the diffusing optical element extends across only a small portion of the light guiding component. The diffusing optical element may extend across, for example, less than 10%, less than 5%, less than 3%, less than 2%, less than 1%, less than 0.5%, or less than 1%, or any range between any of these values, of the area of ​​the light guiding component. The outcoupling optical element may direct light guided within the light guiding component so that at least a portion of the light may exit.

[0247] As discussed above, in some configurations, light is emitted out of the light directing optical element toward the user's eye to illuminate the user's eye, for example with infrared light, for eye tracking. In some implementations, one or more cameras are used to capture images of the eye illuminated by the illumination source. In some configurations, a time-multiplexing approach may be used in conjunction with the cameras to increase eye tracking robustness.

[0248] In some configurations, light is emitted out of the light directing optical element towards the environment in front of the user, potentially illuminating objects in the environment and providing depth sensing, for example.

[0249] In some implementations, at least one illumination source may emit visible light that is coupled out from the light directing optical element to provide a visual cue (e.g., an alert, a notification, etc.) to the user and / or the user's environment. For example, in some embodiments, the visible light may be coupled out (e.g., to bystanders other than the user) to provide a flickering color (e.g., red) illumination pattern. In some configurations, for example, the flickering illumination pattern may indicate that the eyepiece is recording video. In some designs, the visible light may be coupled out (e.g., to the user) to provide a pulsing color (e.g., green) illumination pattern. In some designs, for example, the pulsing (e.g., green) illumination pattern may indicate that the user has an unread message (e.g., email, text message) or may be used to provide another form of alert.

[0250] In some implementations, at least one illumination source may emit visible light that is outcoupled from light-directing optical elements to provide aesthetic enhancements and / or entertainment-driven special visual effects. For example, in some designs, visible light may be outcoupled to surround the user's visual periphery with a glowing and / or varying color (e.g., blue) halo while the user is engaged in an activity such as a deep-sea diving mixed reality experience, thereby creating a greater sense of immersion.

[0251] In some configurations, at least one illumination source may emit visible and / or invisible (e.g., IR or UV) light that is externally coupled from the light directing optical element to the user and / or the user's environment to produce an illumination pattern that may serve to provide one or more recognizable signals or reference points to external imaging sensors (e.g., third-party cameras, other head-mounted displays, etc.) located within the environment.

[0252] Thus, one or more eye-tracking cameras, depth sensors, or other components may additionally be included. Similarly, one or more displays for projecting image content into the user's eye may also be included. Similarly, any of the features, structures, variations, applications, uses, advantages, etc. described above may be used in conjunction with or applicable to implementations that employ diffusing optical elements or scattering regions to provide illumination.

[0253] In some embodiments, the image projector and illumination source of the head mounted display share the same incoupling optics and light directing components. outer and inner covers or shields

[0254] As described above, in some implementations, a light directing component for providing illumination (e.g., to the eye for eye tracking) complements an eyepiece that includes one or more waveguides for directing light from one or more displays to the eye and providing image content thereto. Figures 13A-13B show an example of such a configuration, where the light directing component includes a cover or shield.

[0255] In particular, Figure 13A illustrates a light directing component comprising an outer cover or shield 1200 in front of a light directing element 1202. In this particular embodiment, the outer cover 1200 is curved. Figure 13A also shows a waveguide 1202 having an internal coupling grating (ICG), a light distribution element (OPE) 1210, and an external coupling optical element (EPE) 1212 configured to receive light from a display (not shown) and direct the light from the display to a user's eye to present image content thereto. Figure 13A also shows the outer cover 1200 in front of the waveguide 1202. An internal coupling element 1208 is positioned to couple light from an illumination source into the light directing component 1200, which comprises an outer cover.

[0256] The system further includes an illumination source 1204 configured to couple light into an internal coupling optical element 1208 so that the light is guided within the light directing component 1200. Figure 13B shows the light directing component / cover 1200 without the eyepiece with the waveguide 1202 behind the light directing component / cover 1200. Figure 13B also shows light being projected out of the light directing component / cover 1200 to a user's eye (not shown) using diffusing optical elements 1222A, 1222B, 1222C, 1222D, 1222E disposed in or on the outer cover 1200. These diffusing optical elements 1222A, 1222B, 1222C, 1222D, 1222E have relatively small lateral extent compared to, for example, the light directing component / cover 1200. As a result, the light emitted from the light directing component / cover 1200 by the diffusing optical elements 1222A, 1222B, 1222C, 1222D, 1222E can be considered to effectively emanate from multiple individual point sources.

[0257] In various implementations, the light guidance component / cover 1200 provides a protective cover for the eyepiece 1202. The light guidance component / cover 1200 may include, for example, plastic, such as polycarbonate and / or acrylic, glass, or any combination thereof. As shown, the cover 1200 is in front of the eyepiece 1202, which is in front of the user's eye. However, the cover 1200 is behind the environment in front of the user. The cover 1200 may be supported by a frame, not shown. The cover 1200 may protect the eyepiece 1202 from the environment in front of the user. In the example illustrated in FIGS. 13A-13B, the cover 1200 is curved in one direction more than in another (e.g., orthogonal) direction. The cover 1200 has a cylindrical shape. In particular, the cover 1200 is curved in one direction (vertical) and not curved in the other orthogonal direction (horizontal). The cover 1200 has the shape of a portion of a right circular cylinder. Although the cover is shown as being curved, the cover need not be curved or have the particular curved shape shown.

[0258] In some embodiments, the outer cover may be placed over the eyepiece and act as a shield. In some embodiments, the head-mounted display may include a visor, the visor comprising the outer cover with a light-directing component. Thus, in various implementations, the outer cover and / or the light visor are configured to direct illumination from the illumination source to the user's eyes or the environment (e.g., using total internal reflection).

[0259] As described above, a light directing component for providing illumination (e.g., to the eye for eye tracking) can complement the eyepiece, which includes one or more waveguides for directing light from one or more displays to the eye and providing image content thereto. In particular, the light directing component can include a cover or shield, which may be positioned behind the eyepiece.

[0260] 14A-14B particularly show a light directing component that includes an inner cover or shield 1300 behind an eyepiece (e.g., a light directing element configured to display image content) 1302. In this particular example, the inner cover 1300 is not curved and is flat. FIG. 14A also shows a waveguide 1302 having an internal coupling grating (ICG), a light distribution element (OPE) 1310, and an external coupling optical element (EPE) 1312 configured to receive light from a display (not shown) and direct the light from the display to a user's eye to present image content thereto. FIG. 14A also shows the inner cover 1300 behind the waveguide 1302.

[0261] The system further includes an illumination source 1304 configured to couple light into an internal coupling optical element (e.g., a prism) 1308 so that the light is guided within the light directing component 1300. FIG. 14B shows the light directing component / cover 1300 without an eyepiece, with the waveguide 1202 in front of the light directing component / cover 1300. FIG. 14B also shows light being projected out of the light directing component / cover 1300 and into a user's eye (not shown) using diffusing optical elements 1322A, 1322B, 1322C, 1322D, 1322E disposed in or on the inner cover 1300. These diffusing optical elements 1322A, 1322B, 1322C, 1322D, 1322E have relatively small lateral extents compared to, for example, the light directing component / cover 1300. As a result, the light emitted from the light directing component / cover 1300 by the diffusing optical elements 1322A, 1322B, 1322C, 1322D, 1322E can be considered to effectively emanate from multiple individual point sources.

[0262] In various implementations, the light guidance component / cover 1300 provides a protective cover for the eyepiece 1302. The light guidance component / cover 1300 may include, for example, plastic, such as polycarbonate and / or acrylic, and glass, or any combination thereof. As shown, the cover 1300 is behind the eyepiece 1202, both in front of the user's eye and behind the environment in front of the user. The cover 1200 may be supported by a frame, not shown. The cover 1200 may protect the rear side of the eyepiece 1202. While the cover 1200 is shown as being flat or planar, the cover need not be flat and may be curved, or curved in one direction rather than orthogonally (e.g., cylindrical).

[0263] In some implementations, the display includes one or more covers. In some designs, the covers may be for aesthetics, tinting, impact resistance, or a combination thereof. For example, the covers can obscure system components behind the cover for a neater (e.g., less cluttered) look to the display. In some configurations, the display may also include a front band and sensor cover to protect system components while forming a continuous front of the display around the external lens. The covers, in some instances, may have 50% to 70% transparency (which may be provided by tinting), which may potentially improve or optimize AR experiences involving light from both virtual objects and real-world physical objects.

[0264] In some designs, the display may further include one or more (e.g., pairs of) inner covers to protect system components and / or form a protective inner surface for the display adjacent the user's face. In some implementations, the display may include one or more optional prescription lenses to accommodate users requiring corrective lenses. In some designs, the mounting structure may house covers positioned on either the environment side or the user side of the viewing optical assembly.

[0265] In some implementations, the cover or cover lens may comprise a scratch-resistant material or other protective coating to prevent contact of the display with oils from fingertips or dust and debris from the external environment. In some configurations, the cover or cover lens may include a light modifier, such as a polarized lens, to reflect or absorb some light. In some designs, the display comprises such a protective cover or cover lens in addition to multiple waveguides.

[0266] Either the cover or the lens may include a light directing component and be configured to direct light from the illumination source (eg, via total internal reflection).

[0267] Variations in design and configuration are possible. For example, outcoupling may be provided by a diffractive optical element such as a hologram, or a virtual light source may be provided that is located on a depth plane separate from the cover. Similarly, a mask with openings may be employed. Still other arrangements, configurations, and combinations are possible. frame

[0268] 15A-15B, the light directing component may form part of the frame. Thus, the light directing component for providing illumination (e.g., to the eye for eye tracking) can complement an eyepiece with one or more waveguides for directing light from one or more displays to the eye and providing image content thereto.

[0269] 15A-15B show, among other things, a light directing component 1400 forming part of a frame that surrounds an eyepiece (e.g., a waveguide configured to display image content) 1402. Figure 15A also shows the eyepiece / waveguide 1402 having a light distribution element (OPE) 1410 and an external coupling optical element (EPE) 1412 configured to receive light from a display (not shown) and direct the light from the display to a user's eye to present image content thereto.

[0270] Figure 15A also shows portions of a frame that surround the eyepiece / waveguide 1402. One of the portions of the frame constitutes a light guiding component 1400 for transmitting light therethrough. Figure 15A also shows an illumination source 1404 that is configured to couple light into an internal coupling optical element (e.g., a prism) 1408 so that the light is guided within the light guiding component 1400 contained within the portion of the frame.

[0271] In some implementations, the portion of the frame comprising the light directing component 1400 may include a material that is transparent to the light output by the illumination source 1404 and may have a refractive index sufficient to allow such light to be guided therein by total internal reflection. In some alternative implementations, the portion of the frame comprising the light directing component 1400 may comprise a hollow cavity having sidewalls from which light from the illumination source 1404 may reflect, thereby causing the light to propagate within the light directing component.

[0272] 15B also shows light being emitted from the light directing component 1400 to a user's eye (not shown) using diffusing optical elements 1422A, 1422B, 1422C, 1422D, 1422E disposed within or on the light combining component 1300. These diffusing optical elements 1422A, 1422B, 1422C, 1422D, 1422E have relatively small lateral extents compared to, for example, the light directing component 1400. As a result, the light emitted by the diffusing optical elements 1422A, 1422B, 1422C, 1422D, 1422E from the light directing component 1400 can effectively be considered to emanate from multiple individual point sources.

[0273] In some embodiments, the diffusing optical elements 1422A, 1422B, 1422C, 1422D, 1422E are disposed on a surface of a frame, which may be solid or hollow. The diffusing optical elements may also be disposed within the volume of a hollow or solid frame.

[0274] In some instances where the light guiding component 1400 forms a portion on the frame and the outcoupling optical element is included on this portion of the frame, light may be emitted from a peripheral region, as opposed to the light guiding component discussed above, which is more centrally located relative to the field of view of the user's eye. In this example, multiple light beams are projected from the diffusing optical element onto the user's eye. Furthermore, the multiple beams are arranged along a line. Other designs are also possible. For example, fewer beams (e.g., even a single beam) may be used. Additionally, the beams need not be arranged in a line. Similarly, while the portion of the frame comprising the light guiding component 1400 is generally linear, the shape may be nonlinear. Other nonlinear light guiding shapes and structures may be used. In some implementations, the frame may include multiple arms configured to contact and / or secure the frame to the user's head, and light may be incoupled into and / or outcoupled from one or more arms of the frame.

[0275] Variations in design and configuration are possible. For example, outcoupling may be provided by a diffractive optical element, such as a hologram, to provide a virtual light source located on a depth plane separate from the frame. Similarly, a mask with openings may be employed. Still other arrangements, configurations, and combinations are possible. Other shapes

[0276] Multiple patterns and / or geometries of light directing components, out-coupling elements, masks and mask openings, and diffusing optical elements may be used. FIG. 16 illustrates a circular-shaped light directing component. FIG. 16 also illustrates an annular- or ring-shaped diffusing optical element pattern. Regions comprising diffusing optical elements or scattering features may be configured to extract light from the light coupling component. The emitted light may therefore be emitted from this annular- or ring-shaped region. Other shapes are also possible. Additionally, in this example, the region comprises a diffusing optical element, but the region could otherwise comprise one or more diffractive optical elements or a mask with holograms or openings as described above. Combinations of these types of features are also possible.

[0277] Other shapes are possible. For example, although the light directing component is circular in shape, the light directing component may be elliptical or oval in shape, square, rectangular, or other regular or irregular shape. The light directing component may be flat, e.g., planar, or curved.

[0278] In some implementations, the outcoupling elements, mask openings, and / or diffusing optical elements are located peripherally on the light directing component. In some designs, the outcoupling elements, mask openings, and / or diffusing optical elements are located centrally on the light directing component. In some configurations, the shape of the distribution of the outcoupling elements, mask openings, and / or diffusing optical elements across the light directing component is annular or circular, or has other shapes, such as linear.

[0279] In some implementations, the density of the distribution of outcoupling elements, mask openings, and / or diffusing optical elements across the light directing component is greater than or equal to 1 element / mm 2 , 5 elements / mm 2 , 10 elements / mm 2 , 50 elements / mm 2 , 100 elements / mm 2 , 500 elements / mm 2 , 1,000 elements / mm 2 , 10,000 elements / mm 2 , 1 element / μm 2 , 5 elements / μm 2 , 10 elements / μm 2 , 50 elements / μm 2 , 100 elements / μm 2 , 500 elements / μm 2 , 1,000 elements / μm 2 , or 10,000 elements / μm 2 , or any range between any of these values. Other variations are also possible. Stack of light-guiding components and / or outcoupling optical elements

[0280] In some instances, a stack of multiple light directing components and / or outcoupling elements may be employed.

[0281] 17A, for example, illustrates first and second light guiding components stacked on top of each other. In this example, the first and second light guiding components are separated by an outcoupling optical element, for example, comprising a diffusive or diffractive optical element configured to couple light guided within the first and second light guiding components out of the light guiding components. In some implementations, the outcoupling is bidirectional, with light being injected both forward and backward from the pair of light guiding components.

[0282] 17B illustrates a light guiding component with first and second outcoupling optical elements disposed on opposite sides of the light guiding component to couple light guided within the light guiding component out of the light guiding component. In some embodiments, the first and second outcoupling optical elements may be configured to provide bidirectional outcoupling such that light is ejected forward and backward from the light guiding component and the pair of outcoupling optical elements.

[0283] 17C illustrates first and second light guiding components on opposite sides of one or more outcoupling optical elements, e.g., comprising a diffractive or diffractive optical element configured to couple light guided within the first and second light guiding components out of the light guiding components. In some implementations, the outcoupling is bidirectional, with light being injected forward and backward through the pair of light guiding components. As shown, the first and second light guiding components are circularly shaped and the outcoupling optical element is annularly shaped.

[0284] Although a diffractive optical element may be used in these examples, in other implementations the outcoupling optical element may comprise a diffractive optical element. Other components, such as a mask with one or more openings or other features or structures described herein, may also be used. Also, the shape and distribution may vary. Other features may also vary.

[0285] In some embodiments, directing light from an illumination source toward the environment may provide depth sensing. In some embodiments, directing light toward a user and / or the environment may provide an indication to the user and / or the world. For example, a light may indicate that the wearable is recording video. For example, in some implementations, a visible light may be coupled out and provide a blinking (e.g., red) illumination pattern to indicate that the eyepiece is recording video. In another example, in some configurations, a visible light may be coupled out and provide a pulsating (e.g., green) illumination pattern to indicate that the user has an unread message (e.g., email, text message) or provide another message or alert.

[0286] In some implementations, directing light toward the user and / or the environment may be for aesthetic purposes and / or to provide special effects. For example, in some designs, visible light may be outcoupled to surround the user's visual periphery with a glowing and / or fluctuating (e.g., blue) halo while the user engages in an activity such as a deep-sea diving mixed reality experience, thereby creating a greater sense of immersion.

[0287] In some configurations, at least one illumination source may emit visible and / or invisible (e.g., IR or UV) light that is externally coupled from the light directing optical element to the user and / or the user's environment to produce an illumination pattern that may serve to provide one or more reference points or signals that are recognizable to external imaging sensors (e.g., third-party cameras, head-mounted displays, etc.) located within the environment.

[0288] In some embodiments, the light is coupled out using a virtual light source architecture, in some embodiments, the light is coupled out using a mask architecture, in some embodiments, the light is coupled out using a diffractive optical element architecture. (Example)

[0289] Various examples are provided below. [Example]

[0290] 1. A head mounted display system configured to project light onto an eye of a user wearing the head mounted display system to display content within the user's field of view, comprising: a frame configured to be supported on a user's head; and an image projector configured to project an image; at least one illumination source; a light guiding component configured to be positioned in front of one of the user's eyes when the frame is worn by the user; and at least one illumination in-coupling optical element configured to in-couple light from the at least one illumination source into the light directing component so as to direct light from the at least one illumination source therein; at least one diffusing optical element disposed on the light directing component so as to be positioned in front of one of the user's eyes when the frame is worn by a user, the at least one diffusing optical element configured to diffusively couple light from the at least one illumination source out of the light directing component; A head-mounted display system comprising: [Example]

[0291] 1. A head mounted display system configured to project light onto an eye of a user wearing the head mounted display system to display content within the user's field of view, comprising: a frame configured to be supported on a user's head; and an image projector configured to project an image; at least one illumination source; a light guiding component configured to be positioned in front of one of the user's eyes when the frame is worn by the user; and at least one illumination in-coupling optical element configured to in-couple light from the at least one illumination source into the light directing component so as to direct light from the at least one illumination source therein; at least one outcoupling optical element disposed on the light guiding component so as to be positioned in front of one of the user's eyes when the frame is worn by a user, the at least one outcoupling optical element configured to couple light from the at least one illumination source out of the light guiding component and to diverge the light coupled out of the light guiding component to match light originating from a location at a distance in front of the light guiding component; A head-mounted display system comprising: [Example]

[0292] 1. A head mounted display system configured to project light onto an eye of a user wearing the head mounted display system to display content within the user's field of view, comprising: a frame configured to be supported on a user's head; and an image projector configured to project an image; at least one illumination source; a light guiding component configured to be positioned in front of one of the user's eyes when the frame is worn by the user; and at least one illumination in-coupling optical element configured to in-couple light from the at least one illumination source into the light directing component so as to direct light from the at least one illumination source therein; at least one mask including at least one mask opening disposed on the light directing component so as to be positioned in front of one of the user's eyes when the frame is worn by the user, the at least one mask and the at least one mask opening configured to couple light from the at least one illumination source out of the light directing component through the at least one mask opening; A head-mounted display system comprising: [Example]

[0293] 1. A head mounted display system configured to project light onto an eye of a user wearing the head mounted display system to display content within the user's field of view, comprising: a frame configured to be supported on a user's head; and an image projector configured to project an image; at least one illumination source; a light guiding component configured to be positioned in front of one of the user's eyes when the frame is worn by the user; and at least one illumination in-coupling optical element configured to in-couple light from the at least one illumination source into the light directing component so as to guide the light from the at least one illumination source therein, the at least one in-coupling optical element comprising a prism; wherein the light directing component is configured such that light from an illumination source that is directed within the light directing component is coupled out of the light directing component. [Example]

[0294] 1. A head mounted display system configured to project light onto an eye of a user wearing the head mounted display system to display content within the user's field of view, comprising: a frame configured to be supported on a user's head; and an image projector configured to project an image; at least one illumination source; a light guiding component configured to be positioned in front of one of the user's eyes when the frame is worn by the user; and at least one illumination in-coupling optical element configured to in-couple light from the at least one illumination source into the light directing component so as to direct light from the at least one illumination source therein; Equipped with the light directing component is configured such that light from the illumination source that is directed within the light directing component is coupled out of the light directing component; the image projector is configured to incouple an image, and the at least one illumination source is configured to incouple light into the at least one illumination incoupling optical element; Head-mounted display system. [Example]

[0295] 1. A head mounted display system configured to project light onto an eye of a user wearing the head mounted display system to display content within the user's field of view, comprising: a frame configured to be supported on a user's head; and an image projector configured to project an image; at least one illumination source; a light guiding component configured to be positioned in front of one of the user's eyes when the frame is worn by the user; and at least one illumination in-coupling optical element configured to in-couple light from the at least one illumination source into the light directing component so as to direct light from the at least one illumination source therein; an eyepiece configured to direct light into the user's eye and display augmented reality image content in the user's field of view, at least a portion of the eyepiece being transparent and positioned at a location in front of the user's eye when the user wears the frame such that the transparent portion transmits light from an environment in front of the user to the user's eye and provides a view of the environment in front of the user; wherein the eyepiece comprises a waveguide and at least one image incoupling optical element configured to incoupling light from an image projector into the waveguide so as to guide the light from the image projector therein. [Example]

[0296] 1. A head mounted display system configured to project light onto an eye of a user wearing the head mounted display system to display content within the user's field of view, comprising: a frame configured to be supported on a user's head; and an image projector configured to project an image; at least one illumination source; a light guiding component configured and curved to be positioned in front of one of the user's eyes when the frame is worn by the user; and at least one illumination in-coupling optical element configured to in-couple light from the at least one illumination source into the light directing component so as to direct light from the at least one illumination source therein; wherein the light directing component is configured such that light from an illumination source that is directed within the light directing component is coupled out of the light directing component. [Example]

[0297] 1. A head mounted display system configured to project light onto an eye of a user wearing the head mounted display system to display content within the user's field of view, comprising: a frame configured to be supported on a user's head; and an image projector configured to project an image; at least one illumination source; a light guiding component configured to be positioned in front of one of the user's eyes when the frame is worn by the user, the light guiding component forming part of the frame; at least one illumination in-coupling optical element configured to in-couple light from the at least one illumination source into the light directing component so as to direct light from the at least one illumination source therein; wherein the light directing component is configured such that light from an illumination source that is directed within the light directing component is coupled out of the light directing component. [Example]

[0298] 1. A head mounted display system configured to project light onto an eye of a user wearing the head mounted display system to display content within the user's field of view, comprising: a frame configured to be supported on a user's head; and an image projector configured to project an image; at least one illumination source; a light guiding component configured to be positioned in front of one of the user's eyes when the frame is worn by the user; and at least one illumination in-coupling optical element configured to in-couple light from the at least one illumination source into the light directing component so as to direct light from the at least one illumination source therein; at least one outcoupling optical element disposed on the light directing component so as to be positioned in front of one of the user's eyes when the frame is worn by a user, the at least one outcoupling optical element configured to couple light from the at least one illumination source out of the light directing component; wherein the light directing component comprises two light directing components disposed on opposite sides of the at least one out-coupling optical element. [Example]

[0299] 10. The system of any preceding embodiment, wherein the image projector comprises a visible light source and a modulator. [Example]

[0300] 10. The system of any preceding embodiment, wherein the light modulator comprises a spatial light modulator. [Example]

[0301] 10. The system of any of the preceding examples, wherein the at least one illumination source comprises an infrared (IR) light source configured to emit IR light. [Example]

[0302] 10. The system of any of the preceding examples, wherein the at least one illumination source comprises a visible light source configured to emit visible light. [Example]

[0303] 10. The system of any of the preceding examples, wherein the light directing component comprises a material transparent to visible light having a refractive index sufficient to direct light from the at least one illumination source within the light directing component by total internal reflection. [Example]

[0304] A system as described in any of the above examples, wherein at least a portion of the light directing component is transparent and positioned in a location in front of the user's eye when the user wears the frame so as to transmit light from the environment in front of the user to the user's eye and provide a view of the environment in front of the user. [Example]

[0305] 10. The system of any of the preceding embodiments, wherein the at least one illumination in-coupling optical element comprises at least one prism. [Example]

[0306] 10. The system of any of the preceding examples, further comprising at least one image incoupling optical element configured to incoupling light from the image projector into the light directing component so as to direct light from the image projector therein. [Example]

[0307] 10. The system of any of the preceding examples, wherein the image projector is configured to incoupling an image and the at least one illumination source is configured to incoupling light into the at least one illumination incoupling optical element. [Example]

[0308] The system of any of the above examples further comprises an eyepiece configured to direct light into the user's eye and display augmented reality image content in the user's field of view, at least a portion of the eyepiece being transparent and positioned in a location in front of the user's eye when the user wears the frame so as to transmit light from the environment in front of the user to the user's eye and provide a view of the environment in front of the user. [Example]

[0309] A system as described in any of the above examples, wherein the eyepiece lens comprises a waveguide and at least one image incoupling optical element configured to incoupling light from the image projector into the waveguide so as to guide the light from the image projector therein. [Example]

[0310] 10. The system of any of the preceding embodiments, wherein the light directing component is disposed on an inner portion of the eyepiece, the inner portion being between the user's eye and the eyepiece. [Example]

[0311] 10. The system of any of the preceding embodiments, wherein the light-guiding component is disposed on an outer portion of the eyepiece, the outer portion being between the environment and the eyepiece. [Example]

[0312] 10. The system of any preceding embodiment, wherein the light directing component is curved. [Example]

[0313] 10. The system of any preceding embodiment, wherein the light directing component has the shape of a portion of a cylinder. [Example]

[0314] 10. The system of any preceding embodiment, wherein the light directing component comprises a shield or visor attached to the frame. [Example]

[0315] 10. The system of any preceding embodiment, wherein the shield or visor is disposed on an interior portion of the display system. [Example]

[0316] 10. The system of any preceding embodiment, wherein the shield or visor is disposed on an outer portion of the display system. [Example]

[0317] The system of any preceding embodiment, wherein the light directing component forms part of the frame. [Example]

[0318] 10. The system of any of the preceding examples, wherein the at least one diffusing optical element is configured to couple light from the at least one illumination source out of the light directing component and towards the user's eye. [Example]

[0319] A system as described in any of the above examples, wherein the at least one diffusing optical element is configured to couple light from the at least one illumination source out of the light guiding component toward the user's eyes and toward an environment in front of the user. [Example]

[0320] The system of any of the previous examples, wherein at least one mask blocks light guided within the light directing component from exiting the light directing component. [Example]

[0321] 10. The system of any preceding embodiment, wherein the at least one mask reflects light from the at least one illumination source back into the light directing component. [Example]

[0322] 10. The system of any of the preceding embodiments, wherein the at least one mask is dichroic, reflecting certain wavelengths emitted by the at least one illumination source and transmitting other wavelengths not emitted by the at least one illumination source. [Example]

[0323] 10. The system of any of the preceding examples, wherein the at least one mask is dichroic, reflecting certain infrared wavelengths emitted by the at least one illumination source and transmitting other visible wavelengths not emitted by the at least one illumination source. [Example]

[0324] 10. The system of any preceding embodiment, wherein the at least one mask is configured to absorb light emitted by the illumination source. [Example]

[0325] The system of any of the preceding examples, wherein the at least one mask opening is about 10 μm in diameter. [Example]

[0326] The system of any of the previous examples, wherein the at least one diffusing optical element extends across an area that is less than 5% of an area of ​​the at least one light directing component. [Example]

[0327] The system of any of the previous examples, wherein the at least one mask opening extends across an area that is less than 5% of an area of ​​the at least one light directing component. [Example]

[0328] 10. The system of any of the preceding examples, further comprising a light redirecting element configured to direct light received from the at least one illumination in-coupling optical element into the light directing component such that the light directing component redirects the light to the at least one diffusing optical element. [Example]

[0329] 10. The system of any of the preceding examples, further comprising a light redirecting element configured to direct light received from the at least one illumination in-coupling optical element into the light directing component such that the light directing component redirects the light to the at least one mask opening. [Example]

[0330] 10. The system of claim 1, further comprising a light redirecting element configured to direct light received from the at least one illumination in-coupling optical element into the light guiding component such that the light guiding component redirects the light to the at least one out-coupling element. [Example]

[0331] 10. The system of any preceding example embodiment, wherein the light redirecting element comprises an orthogonal pupil expander. [Example]

[0332] 10. The system of any of the preceding examples, further comprising at least one camera configured to image the user's eye using light from the at least one illumination source reflected from the eye. [Example]

[0333] 10. The system of any of the preceding examples, wherein the at least one camera comprises an eye-tracking camera configured to communicate with electronics configured to track movement of the eye based on images from the at least one camera. [Example]

[0334] 10. The system of any preceding embodiment, wherein the light directing component has a circular shape. [Example]

[0335] 10. The system of any of the preceding examples, wherein the light directing component comprises two light directing components positioned on opposite sides of the at least one diffusing optical element. [Example]

[0336] The system of any of the preceding examples, wherein the at least one light directing component comprises first and second light directing components disposed on opposite sides of a diffusion film. [Example]

[0337] 10. The system of any of the preceding examples, wherein the at least one diffusing optical element comprises a pair of diffusing optical elements disposed on opposite sides of the light directing component. [Example]

[0338] The system of any of the preceding examples, wherein the at least one diffusing optical element comprises first and second diffusing films disposed on opposite sides of the light directing component. [Example]

[0339] The system of any of the above examples, wherein the at least one diffusive optical element comprises first and second diffusive optical elements configured to direct light into distributions oriented in different first and second directions. [Example]

[0340] The system of any of the above examples, wherein the at least one diffusing optical element comprises first and second diffusing optical elements configured to selectively direct light having first and second wavelengths into distributions oriented in different first and second directions, respectively, and the at least one illumination source comprises first and second light sources that selectively emit the first and second wavelengths, respectively. [Example]

[0341] 10. The system of any of the preceding embodiments, wherein the at least one illumination source comprises a plurality of illumination sources. [Example]

[0342] 10. The system of any of the preceding embodiments, wherein the at least one illumination source comprises a plurality of illumination sources, and the at least one diffusing optical element directs light from different illumination sources into individual distributions oriented in different directions. [Example]

[0343] The system of any of the preceding examples, wherein the at least one illumination source comprises a plurality of illumination sources, and the at least one diffusing optical element directs light from the different illumination sources as if they originate from different, separate locations in front of the at least one light-guiding component. [Example]

[0344] 10. The system of any of the preceding examples, wherein the at least one illumination source comprises a laser, an LED, or a vertical cavity surface emitting laser (VCSEL). [Example]

[0345] 10. The system of any of the preceding embodiments, wherein the at least one illumination source further comprises at least one filter. [Example]

[0346] 10. The system of any of the preceding embodiments, wherein the at least one diffractive optical element is refractive, reflective, diffractive, or any combination thereof. [Example]

[0347] The system of any of the above examples, wherein the at least one diffusing optical element comprises one or more diffuser sheets, one or more light shaping diffusers, one or more diffuser films, one or more etchings, one or more transmissive optical elements, one or more particles, one or more irregular surfaces, one or more surface relief structures, PTFE, Teflon, frosted glass, milk glass, gray glass, one or more white surfaces, colored gels, one or more holograms, or any combination thereof. [Example]

[0348] A system described in any of the above examples, wherein the at least one diffusing optical element is wavelength selective such that it substantially selectively diffuses one or more wavelengths of light emitted from the at least one illumination source and does not diffuse others. [Example]

[0349] The system of any of the above examples, wherein the system includes a plurality of diffusing optical elements and at least one illumination source emitting a plurality of wavelength bands of light, wherein different ones of the diffusing optical elements selectively diffuse respective ones of the plurality of wavelength bands from the at least one illumination source. [Example]

[0350] 10. The system of any of the preceding embodiments, wherein the at least one diffusing optical element does not redirect visible light from the environment. [Example]

[0351] 10. The system of any preceding embodiment, wherein the at least one diffusing optical element is configured to direct light from the illumination source towards the environment. [Example]

[0352] 10. The system of claim 1, wherein the at least one illumination source comprises an infrared source configured to output infrared light, and the at least one diffusing optical element is configured to direct the infrared light from the at least one illumination source toward the environment to provide depth sensing. [Example]

[0353] The system of any of the above examples, wherein the at least one illumination source comprises a visible light source configured to output visible light, and the at least one diffusing optical element is configured to direct the visible light from the at least one illumination source towards the environment and provide indicia to a non-user. [Example]

[0354] 10. The system of claim 1, wherein the at least one illumination source comprises a visible light source configured to output visible light, and the at least one diffusing optical element is configured to direct the visible light from the at least one illumination source toward the eye and provide an indication to a user. [Example]

[0355] 10. The system of claim 1, wherein the at least one illumination source comprises a visible light source configured to output visible light, and the at least one diffusing optical element is configured to direct the visible light from the at least one illumination source toward the periphery of the eye. [Example]

[0356] 10. The system of claim 1, wherein the at least one illumination source comprises a visible light source, an infrared source, or both, configured to output light, and the at least one diffusing optical element is configured to direct light from the at least one illumination source toward the environment and provide a signal or reference point to an external sensor or external imaging sensor. [Example]

[0357] The system of any of the above examples, wherein the at least one illumination source comprises a visible light source, an infrared source, or both configured to output light, and the at least one diffusing optical element is configured to direct light from the at least one illumination source toward the user and provide a signal or reference point to an external sensor or external imaging sensor. [Example]

[0358] The system of any of the previous examples, wherein the at least one outcoupling optical element extends across an area that is less than 5% of an area of ​​the at least one light guiding component. [Example]

[0359] 10. The system of any of the preceding examples, wherein the light guiding component comprises two light guiding components disposed on opposite sides of the at least one outcoupling optical element. [Example]

[0360] The system of any of the previous examples, wherein the at least one light directing component comprises first and second light directing components disposed on opposite sides of the outcoupling optical film. [Example]

[0361] 10. The system of any of the preceding embodiments, wherein the at least one outcoupling optical element comprises a pair of outcoupling optical elements disposed on opposite sides of the light directing component. [Example]

[0362] 10. The system of any of the preceding examples, wherein the at least one outcoupling optical element comprises first and second outcoupling optical films disposed on opposite sides of the light directing component. [Example]

[0363] The system of any of the above examples, wherein the at least one outcoupling optical element comprises first and second outcoupling optical elements configured to direct light into distributions oriented in different first and second directions. [Example]

[0364] The system of any of the above examples, wherein the at least one outcoupling optical element comprises first and second outcoupling optical elements configured to selectively direct light having first and second wavelengths into distributions oriented in different first and second directions, respectively, and the at least one illumination source comprises first and second light sources that selectively emit the first and second wavelengths, respectively. [Example]

[0365] 10. The system of any of the preceding embodiments, wherein the at least one illumination source comprises a plurality of illumination sources. [Example]

[0366] 10. The system of any of the preceding embodiments, wherein the at least one illumination source comprises a plurality of illumination sources, and the at least one outcoupling optical element directs light from different illumination sources into individual distributions oriented in different directions. [Example]

[0367] The system of any of the preceding examples, wherein the at least one illumination source comprises a plurality of illumination sources, and the at least one outcoupling optical element directs light from the different illumination sources as if they originate from different, separate locations in front of the at least one light-guiding component. [Example]

[0368] 10. The system of any of the preceding examples, wherein the at least one illumination source comprises a laser, an LED, or a vertical cavity surface emitting laser (VCSEL). [Example]

[0369] 10. The system of any of the preceding embodiments, wherein the at least one illumination source further comprises at least one filter. [Example]

[0370] 10. The system of any of the preceding embodiments, wherein the at least one outcoupling optical element is refractive, reflective, diffractive, or any combination thereof. [Example]

[0371] The system of any of the above examples, wherein the at least one outcoupling optical element comprises one or more diffuser sheets, one or more light shaping diffusers, one or more diffuser films, one or more etchings, one or more transmissive optical elements, one or more particles, one or more irregular surfaces, one or more surface relief structures, PTFE, Teflon, frosted glass, milk glass, gray glass, one or more white surfaces, colored gels, one or more holograms, or any combination thereof. [Example]

[0372] 10. The system of any of the preceding embodiments, wherein the at least one outcoupling optical element is wavelength selective such that it interacts substantially only with a wavelength band of light emitted from the at least one illumination source. [Example]

[0373] 10. The system of any of the preceding embodiments, wherein the system comprises a plurality of outcoupling optical elements and at least one illumination source emitting a plurality of wavelength bands of light, each outcoupling optical element being wavelength selective such that it interacts substantially only with a different wavelength band of light emitted from the at least one illumination source. [Example]

[0374] 10. The system of any of the preceding embodiments, wherein the at least one outcoupling optical element does not redirect visible light from the environment. [Example]

[0375] 10. The system of any of the preceding embodiments, wherein the at least one outcoupling optical element is configured to direct light from the illumination source towards the environment. [Example]

[0376] 10. The system of claim 1, wherein the at least one illumination source comprises an infrared source configured to output infrared light, and the at least one outcoupling optical element is configured to direct the infrared light from the at least one illumination source toward the environment to provide depth sensing. [Example]

[0377] The system of any of the above examples, wherein the at least one illumination source comprises a visible light source configured to output visible light, and the at least one outcoupling optical element is configured to direct the visible light from the at least one illumination source towards the environment to provide an indication to a non-user. [Example]

[0378] 10. The system of claim 1, wherein the at least one illumination source comprises a visible light source configured to output visible light, and the at least one outcoupling optical element is configured to direct the visible light from the at least one illumination source toward the eye to provide an indication to a user. [Example]

[0379] 10. The system of claim 1, wherein the at least one illumination source comprises a visible light source configured to output visible light, and the at least one outcoupling optical element is configured to direct the visible light from the at least one illumination source toward the periphery of the eye. [Example]

[0380] 10. The system of claim 1, wherein the at least one illumination source comprises a visible light source, an infrared source, or both, configured to output light, and the at least one outcoupling optical element is configured to direct light from the at least one illumination source toward the environment and provide a signal or reference point to an external sensor or external imaging sensor. [Example]

[0381] The system of any of the above examples, wherein the at least one illumination source comprises a visible light source, an infrared source, or both configured to output light, and the at least one outcoupling optical element is configured to direct light from the at least one illumination source toward the user and provide a signal or reference point to a sensor or external imaging sensor. [Example]

[0382] 10. The system of any of the previous embodiments, wherein the image projector and the illumination source share the same in-coupling optical elements and light directing components. [Example]

[0383] 10. The system of any of the preceding embodiments, wherein the at least one outcoupling optical element comprises at least one diffusing optical element, or at least one diffusing film, or any combination thereof. [Example]

[0384] 10. The system of any of the preceding embodiments, wherein the at least one outcoupling optical element comprises at least one diffractive optical element, or at least one holographic optical element, or any combination thereof. Additional Considerations

[0385] In the foregoing specification, the invention has been described with reference to specific embodiments thereof. It will, however, be apparent that various modifications and changes can be made therein without departing from the broader spirit and scope of the invention. The specification and drawings are, therefore, to be regarded in an illustrative rather than a restrictive sense.

[0386] Indeed, it should be understood that the systems and methods of the present disclosure each have several innovative aspects, no single one of which is solely responsible for or required for the desirable attributes disclosed herein. The various features and processes described above may be used independently of one another or may be combined in various ways. All possible combinations and subcombinations are intended to fall within the scope of the present disclosure.

[0387] Certain features described herein in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, various features described in the context of a single embodiment may also be implemented in multiple embodiments separately or in any suitable subcombination. Furthermore, while features may be described above as acting in a combination and may even be initially exemplified as such, one or more features from the exemplified combination may, in some cases, be deleted from the combination, and the exemplified combination may be directed to a subcombination or variation of the subcombination. No single feature or group of features is required or essential to every embodiment.

[0388] It should be understood that conditional statements used herein, such as "can," "could," "might," "may," "eg," and the like, in particular, are generally intended to convey that certain embodiments include certain features, elements, and / or steps, while other embodiments do not, unless specifically stated otherwise or understood otherwise within the context as used. Thus, such conditional statements are generally not intended to imply that features, elements, and / or steps are in any way required for one or more embodiments, or that one or more embodiments necessarily include logic for determining whether those features, elements, and / or steps are to be included or performed in any particular embodiment, with or without authorial input or prompting. The terms "comprising," "including," "having," and the like, are synonymous and used inclusively in a non-limiting manner and do not exclude additional elements, features, acts, operations, etc. Also, the term "or" is used in its inclusive sense (and not its exclusive sense); thus, for example, when used to connect a list of elements, the term "or" refers to one, some, or all of the elements in the list. Additionally, the articles "a," "an," and "the," as used in this application and the accompanying examples, shall be interpreted to mean "one or more" or "at least one," unless otherwise specified. Similarly, while operations may be depicted in the figures in a particular order, it should be recognized that such operations need not be performed in the particular order shown, or in sequential order, or that all of the illustrated operations need not be performed to achieve desirable results. Furthermore, the figures may diagrammatically depict one or more exemplary processes in the form of a flowchart. However, other operations not depicted may also be incorporated within the diagrammatically illustrated exemplary methods and processes. For example, one or more additional operations may be performed before, after, concurrently with, or during any of the illustrated operations.Additionally, operations may be rearranged or reordered in other embodiments. In some situations, 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 program components and systems described may generally be integrated together in a single software product or packaged in multiple software products. Additionally, other implementations are within the scope of the following examples. In some cases, the actions recited in the examples can be performed in a different order and still achieve desirable results.

[0389] Thus, the present disclosure is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the present disclosure, the principles and novel features disclosed herein.

Claims

1. 1. A head mounted display system configured to display content within a field of view of a user wearing the head mounted display system by projecting light onto the eye of the user, the head mounted display system comprising: a frame configured to be supported on the user's head; an image projector configured to project an image; at least one illumination source; a light guiding component comprising a material transparent to visible light having a refractive index sufficient to guide light from the at least one illumination source within the light guiding component by total internal reflection, the light guiding component having a circular disk shape, the light guiding component configured to be positioned in front of one of the user's eyes when the frame is worn by the user; and at least one illumination in-coupling optical element, the at least one illumination in-coupling optical element configured to incouple light from the at least one illumination source into the light directing component so as to direct light from the at least one illumination source; at least one outcoupling optical element, the at least one outcoupling optical element having an annular shape, the at least one outcoupling optical element being disposed around a periphery of the light guiding component to surround a central position of the light guiding component, the at least one outcoupling optical element being positioned in front of one of the user's eyes when the frame is worn by the user, the at least one outcoupling optical element being configured to couple light from the at least one illumination source out of the periphery of the light guiding component; A head-mounted display system comprising:

2. The light guiding component comprises two light guiding components, The head mounted display system of claim 1 , wherein a component is disposed on an opposite side of the at least one outcoupling optical element.

3. 2. The head-mounted display system of claim 1, wherein the at least one outcoupling optical element comprises at least one diffusing optical element configured to diffusely couple light from the at least one illumination source out of the periphery of the light directing component.

4. The head mounted display system of claim 3 , wherein the light directing component comprises two light directing components, the two light directing components being positioned on opposite sides of the at least one diffusing optical element.

5. The at least one outcoupling optical element is a diffusion film; The head mounted display system of claim 1 , wherein the light directing component comprises a first light directing component and a second light directing component disposed on opposite sides of the at least one outcoupling optical element.

6. 2. The head-mounted display system of claim 1, wherein the at least one outcoupling optical element comprises a first diffusing optical element and a second diffusing optical element configured to direct light into distributions oriented in different first and second directions.

7. 2. The head-mounted display system of claim 1, wherein the at least one external coupling optical element comprises a first diffusing optical element and a second diffusing optical element, the first diffusing optical element and the second diffusing optical element being configured to selectively direct light having a first wavelength and a second wavelength into distributions oriented in different first and second directions, respectively, and the at least one illumination source comprises a first light source and a second light source, the first light source and the second light source selectively emitting the first wavelength and the second wavelength, respectively.

8. The head mounted display system of claim 1 , wherein the at least one outcoupling optical element is refractive, reflective, diffractive, or any combination thereof.

9. The head-mounted display system of claim 1 , wherein the at least one illumination source comprises an infrared (IR) light source, the infrared (IR) light source configured to emit IR light.

10. 10. The head-mounted display system of claim 1, wherein the at least one out-coupling optical element is configured to couple light from the at least one illumination source out of the light directing component toward an eye of the user.

11. 10. The head-mounted display system of claim 1, wherein the at least one out-coupling optical element is configured to couple light from the at least one illumination source out of the light directing component toward an environment in front of the user.

12. 10. The head mounted display system of claim 1, wherein the at least one outcoupling optical element comprises one or more diffuser sheets, one or more light shaping diffusers, one or more diffuser films, one or more etchings, one or more transmissive optical elements, one or more particles, one or more irregular surfaces, one or more surface relief structures, PTFE, Teflon, frosted glass, milk glass, gray glass, one or more white surfaces, colored gels, one or more holograms, or any combination thereof.

13. 2. The head-mounted display system of claim 1, wherein the at least one outcoupling optical element is wavelength-selective such that it substantially selectively diffuses one or more wavelengths of light emitted from the at least one illumination source and does not diffuse other wavelengths.

14. The head mounted display system of claim 1 , wherein the at least one outcoupling optical element is a diffusing optical element that does not redirect visible light from the user's environment.

15. 1. A head mounted display system configured to display content within a field of view of a user wearing the head mounted display system by projecting light onto the eye of the user, the head mounted display system comprising: a frame configured to be supported on the user's head; an image projector configured to project an image; at least one illumination source; a light guiding component comprising a material transparent to visible light having a refractive index sufficient to guide light from the at least one illumination source within the light guiding component by total internal reflection, the light guiding component being circular in shape, the light guiding component being configured to be positioned in front of one of the user's eyes when the frame is worn by the user; at least one illumination in-coupling optical element, the at least one illumination in-coupling optical element configured to incouple light from the at least one illumination source into the light directing component so as to direct light from the at least one illumination source; at least one outcoupling optical element, the at least one outcoupling optical element disposed around a periphery of the light directing component, the at least one outcoupling optical element positioned in front of one of the user's eyes when the frame is worn by the user, the at least one outcoupling optical element configured to couple light from the at least one illumination source out of the periphery of the light directing component; Equipped with The at least one outcoupling optical element comprises a pair of diffusing optical elements disposed on opposite sides of the light directing component.

16. 1. A head mounted display system configured to display content within a field of view of a user wearing the head mounted display system by projecting light onto the eye of the user, the head mounted display system comprising: a frame configured to be supported on the user's head; an image projector configured to project an image; at least one illumination source; a light guiding component comprising a material transparent to visible light having a refractive index sufficient to guide light from the at least one illumination source within the light guiding component by total internal reflection, the light guiding component being circular in shape, the light guiding component being configured to be positioned in front of one of the user's eyes when the frame is worn by the user; at least one illumination in-coupling optical element configured to in-couple light from the at least one illumination source into the light directing component to direct light from the at least one illumination source; at least one illumination incoupling optical element; at least one outcoupling optical element, the at least one outcoupling optical element disposed around a periphery of the light directing component, the at least one outcoupling optical element positioned in front of one of the user's eyes when the frame is worn by the user, the at least one outcoupling optical element configured to couple light from the at least one illumination source out of the periphery of the light directing component; Equipped with The at least one outcoupling optical element comprises a first diffusing film and a second diffusing film disposed on opposite sides of the light directing component.

17. 1. A head mounted display system configured to display content within a field of view of a user wearing the head mounted display system by projecting light onto the eye of the user, the head mounted display system comprising: a frame configured to be supported on the user's head; an image projector configured to project an image; at least one illumination source; a light guiding component comprising a visible light transparent material having a refractive index sufficient to guide light from the at least one illumination source within the light guiding component by total internal reflection, the light guiding component being circular in shape; and at least one illumination in-coupling optical element, the at least one illumination in-coupling optical element configured to incouple light from the at least one illumination source into the light directing component so as to direct light from the at least one illumination source; at least one outcoupling optical element, the at least one outcoupling optical element disposed around a periphery of the light directing component, the at least one outcoupling optical element positioned in front of one of the user's eyes when the frame is worn by the user, the at least one outcoupling optical element configured to couple light from the at least one illumination source out of the periphery of the light directing component; Equipped with A head-mounted display system, wherein at least a portion of the light guiding component is positioned in a location in front of the user's eyes when the user wears the frame, such that the light guiding component transmits light from the environment in front of the user to the user's eyes, thereby providing a view of the environment in front of the user.

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