Efficient collimation of light with optical wedge
AssigneeMicrosoft Corporation
InventorsAdrian Travis, Timothy Large, Neil Emerton, Steven Bathiche
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Abstract
Embodiments of optical collimators are disclosed. For example, one disclosed embodiment comprises an optical waveguide having a first end, a second end opposing the first end, a viewing surface extending at least partially between the first end and the second end, and a back surface opposing the viewing surface. The viewing surface comprises a first critical angle of internal reflection, and the back surface is configured to be reflective at the first critical angle of internal reflection. Further, a collimating end reflector comprising a faceted lens structure having a plurality of facets is disposed at the second end of the optical waveguide.
Claims15
An optical collimator comprising:
- an optical waveguide having
- a first end comprising a first light interface;
- a second end opposite the first end;
- a viewing surface comprising a second light interface extending at least partially between the first end and the second end and having a first critical angle of internal reflection with respect to a normal of the viewing surface;
- a back surface opposing the viewing surface;
- and
- a collimating end reflector arranged at the second end of the optical waveguide, wherein the collimating end reflector comprises a faceted lens structure.
A method of displaying an image with light collimated via an optical waveguide, the optical waveguide comprising a first end, a second end opposite the first end, a collimating end reflector, a viewing surface extending between the first end and the second end, and a back surface opposing the viewing surface, the method comprising:
- injecting light into the first end of the optical waveguide;
- delivering the light to the collimating end reflector via total internal reflection;
- internally reflecting the light off of the collimating end reflector thereby forming collimated light;
- emitting a first portion of collimated light from the viewing surface at a critical angle of reflection;
- internally reflecting a second portion of collimated light from the back surface at an angle equal to the critical angle of reflection;
- emitting the second portion of collimated light from the viewing surface after internally reflecting the second portion of collimated light from the back surface;
- and
- directing the first portion of collimated light and the second portion of collimated light through a light modulator.
Dependencies are inferred from the claim text.