Field of view expansion by image light redirection
AssigneeMeta Platforms Technologies, LLC
InventorBabak Amirsolaimani
Life of this patent
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Abstract
A near-eye display has an image projector coupled to a lightguide for receiving and propagating image light provided by the image projector, the image light carrying an image to be displayed to a viewer. Field of view of the near-eye display may be expanded by providing a beam redirector downstream of the lightguide for controllably redirecting the image light m coordination with displaying different field of view portions by the image projector. To compensate the redirection of external light by the beam redirector, a second beam redirector may be provided upstream of the first redirector and the lightguide.
Claims20
A system comprising:
- a lightguide body for receiving and propagating image light, wherein the lightguide body includes an out-coupling structure for out-coupling the image light;
- and
- a beam redirector downstream of the lightguide body that controllably redirects the image light that was out-coupled by the out-coupling structure,
- wherein the image light includes field of view (FOV) light portions,
- wherein the beam redirector includes a switchable half-wave plate configured to, when in a first state, transmit the image light, or, when in a second state, to transmit the image light with inverted handedness, and
- wherein the beam redirector includes a grating that redirects the image light transmitted by the switchable half-wave plate to the left for left-circular polarized (LCP) light and to the right for right-circular polarized (RCP) light, such that the grating expands the system's field of view by allowing the FOV light portions to be switched.
A near-eye display (NED) comprising:
- an image projector for providing first and second portions of an image in angular domain to be displayed by the near-eye display;
- a lightguide body for receiving and propagating image light, wherein the lightguide body includes an out-coupling structure for out-coupling the image light;
- and
- a beam redirector downstream of the lightguide body that controllably redirects the image light that was out-coupled by the out-coupling structure,
- wherein the image light includes field of view (FOV) light portions,
- wherein the beam redirector includes a switchable half-wave plate configured to, when in a first state, transmit the image light, or, when in a second state, to transmit the image light with inverted handedness, and
- wherein the beam redirector includes a grating that redirects the image light transmitted by the switchable half-wave plate to the left for left-circular polarized (LCP) light and to the right for right-circular polarized (RCP) light, such that the grating expands the NED's field of view by allowing the FOV light portions to be switched.
A lightguide assembly comprising:
- a lightguide body for receiving and propagating image light, wherein the lightguide body includes an out-coupling structure for out-coupling the image light;
- and
- a beam redirector downstream of the lightguide body that controllably redirects the image light that was out-coupled by the out-coupling structure,
- wherein the image light includes field of view (FOV) light portions,
- wherein the beam redirector includes a switchable half-wave plate configured to, when in a first state, transmit the image light, or, when in a second state, to transmit the image light with inverted handedness, and
- wherein the beam redirector includes a grating that redirects the image light transmitted by the switchable half-wave plate to the left for left-circular polarized (LCP) light and to the right for right-circular polarized (RCP) light, such that the grating expands the lightguide assembly's field of view by allowing the FOV light portions to be switched.
Dependencies are inferred from the claim text.