Separated pupil optical systems for virtual and augmented reality and methods for displaying images using same
A method of operating an AR system to display an image viewable by a user's eyes includes tracking, by an eye-tracking subsystem, a position of the user's eyes and determining, based on the position, a focus depth of the user's eyes. The method also includes selecting, from a plurality of light-guiding optical elements, a subset of light-guiding optical elements configured to focus light at a depth plane corresponding to the focus depth of the user's eyes, producing a plurality of light beams using a subset of sub-light sources of a plurality of sub-light sources, the subset of sub-light sources being configured to illuminate the subset of light-guiding optical elements, and imaging the plurality of light beams through an imaging system and onto the subset of light-guiding optical elements such that the image is generated at the depth plane corresponding to the focus depth of the user's eyes.
1. A method of operating an AR system to display an image viewable by a user's eyes, the method comprising:
tracking, by an eye-tracking subsystem, positions of the user's eyes;
determining, based on the positions, a focus depth of the user's eyes;
providing a plurality of sub-light sources;
activating a subset of sub-light sources of the plurality of sub-light sources based on the focus depth of the user's eyes, wherein activating a sub-light source causes the sub-light source to produce a light beam originating from the sub-light source, thereby producing a plurality of light beams;
encoding the plurality of light beams with image data, thereby producing a plurality of encoded light beams;
providing a plurality of light-guiding optical elements, wherein each of a subset of light-guiding optical elements of the plurality of light-guiding optical elements corresponds to one sub-light source of the subset of sub-light sources;
focusing each of the plurality of encoded light beams onto a corresponding one of the subset of light-guiding optical elements of the plurality of light-guiding optical elements; and
projecting, from the subset of light-guiding optical elements that correspond to the subset of sub-light sources, the plurality of encoded light beams into the user's eyes so that they appear to originate from a depth plane corresponding to the focus depth of the user's eyes.
2. The method of claim 1 , wherein others of the plurality of light-guiding optical elements are not illuminated by the subset of sub-light sources.
3. The method of claim 1 , wherein each sub-light source of the plurality of sub-light sources is configured to produce multiple light beams and wherein each light beam of the multiple light beams is spatially separated.
4. The method of claim 1 , wherein encoding the plurality of light beams with the image data comprises using a spatial light modulator to provide the plurality of encoded light beams.
5. The method of claim 4 , wherein each light-guiding optical element of the subset of light-guiding optical elements comprises a respective in-coupling grating that admits the plurality of encoded light beams into the light-guiding optical element.
6. The method of claim 5 , wherein each respective in-coupling grating is arranged around an optical axis that extends from the spatial light modulator to the plurality of light-guiding optical elements.
7. The method of claim 5 , wherein admitting each of the plurality of encoded light beams at the respective in-coupling grating of the corresponding one of the subset of light-guiding optical elements of the plurality of light-guiding optical elements comprises encountering the respective in-coupling grating only once.
8. The method of claim 4 , wherein the plurality of sub-light sources are arranged around an optical axis that extends from the spatial light modulator to the plurality of sub-light sources.
9. The method of claim 4 , further comprising modifying a shape of a pupil formed by each of the plurality of encoded light beams using a mask.
10. The method of claim 9 , wherein the mask is adjacent to the plurality of light-guiding optical elements.
11. The method of claim 4 , further comprising modifying a size of a pupil formed by each of the plurality of encoded light beams using an optical element, wherein the optical element is adjacent to the plurality of light-guiding optical elements.
12. The method of claim 1 , wherein focusing each of the plurality of encoded light beams onto the corresponding one of the subset of light-guiding optical elements comprises using an injection optical system.
13. The method of claim 12 , wherein the injection optical system is characterized by an eccentric cross-section along an optical path of the injection optical system.
14. The method of claim 1 , wherein each beam of the plurality of light beams differs from other beams of the plurality of light beams in at least one light property.
15. The method of claim 14 , wherein the at least one light property comprises color.
16. The method of claim 14 , wherein the at least one light property comprises polarization.
17. The method of claim 1 , wherein each of the plurality of sub-light sources are spatially separated from each other.
18. The method of claim 1 , further comprising increasing a numerical aperture of the plurality of sub-light sources using a pupil expander.
19. The method of claim 18 , wherein the pupil expander comprises a film having a prism pattern disposed thereon.
20. The method of claim 1 , wherein activating the subset of sub-light sources comprises deactivating remaining sub-light sources of the plurality of sub-light sources.