Imaging light guide with reflective turning array
AssigneeVuzix Corporation
InventorsRobert J. Schultz, Paul J. Travers
Life of this patent
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Abstract
An imaging light guide has a waveguide and an in-coupling diffractive optic formed on the waveguide and disposed to direct image-bearing light beams into the waveguide. An array of two or more at least partially reflective surfaces are oriented in parallel and disposed to expand the image-bearing light beams from the in-coupling diffractive optic in a first dimension and to direct the expanded image-bearing light beams toward an out-coupling diffractive optic. The out-coupling diffractive optic is formed on the waveguide and disposed to expand the image-bearing light beams in a second dimension orthogonal to the first dimension and to direct the image-bearing light beams toward a viewer eyebox.
Claims22
An imaging light guide for conveying a virtual image, comprising:
- a waveguide;
- an in-coupling diffractive optic having a first grating vector, wherein the in-coupling diffractive optic is arranged to direct image-bearing light beams into the waveguide;
- and
- a reflector array of two or more at least partially reflective surfaces oriented in parallel and arranged to expand the respective image-bearing light beams from the in-coupling diffractive optic in a first dimension and to direct the expanded image-bearing light beams toward an out-coupling diffractive optic, wherein the two or more at least partially reflective surfaces are specularly reflective, and
- wherein the out-coupling diffractive optic has a second grating vector parallel to the first grating vector and is disposed to expand the respective image-bearing light beams in a second dimension orthogonal to the first dimension and to direct the image-bearing light beams from the waveguide toward an eyebox.
An imaging light guide for conveying a virtual image, comprising:
- a) an in-coupling diffractive optic formed on a flat substrate, the in-coupling diffractive optic having a first grating vector, wherein the in-coupling diffractive optic is arranged to diffract incident image-bearing light beams into the substrate;
- b) first and second at least partially reflective surfaces arranged in parallel along or within the substrate, and
- c) an out-coupling diffractive optic formed on the substrate, the out-coupling diffractive optic having a second grating vector parallel to the first grating vector, wherein the out-coupling diffraciive optic is arranged to direct the image-bearing light beams outward from the substrate,
- wherein the first at least partially reflective surface is partially reflective and partially transmissive, the second at least partially reflective surface is more fully reflective,
- wherein the first partially reflective and partially transmissive surface is arranged (a) to reflect portions of the image-bearing light beams reflected by the second more fully reflective surface back toward the second more fully reflective surface and (b) to transmit portions of the image-bearing light beams reflected by the second more fully reflective surface toward the out-coupling diffractive optic, and
- wherein the first and second at least partially reflective surfaces are specularly reflective.
A method of making an imaging light guide, comprising:
- a) forming an in-coupling diffractive optic on a planar substrate, wherein the in-coupling diffractive optic has a first grating period and a first grating vector;
- b) forming an out-coupling diffractive optic on the planar substrate, wherein the out-coupling diffractive optic has a second grating period equal to the first grating period and a second grating vector that is parallel to the first grating vector;
- and
- c) forming a reflector array along or within the planar substrate and disposed to direct diffracted light from the in-coupling diffractive optic to the out-coupling diffractive optic,
- wherein the reflector array is formed with two or more at least partially reflective surfaces oriented in parallel and wherein each of the two or more at least partially reflective surfaces is formed having a different reflectivity,
- wherein the two or more at least partially reflective surfaces are specularly reflective.
Dependencies are inferred from the claim text.