US 11,994,684 B2
Image light guide with zoned diffractive optic
Robert J. Schultz, Victor, NY (US); Marek W. Kowarz, Henrietta, NY (US); and Robert W. Gray, Rochester, NY (US)
Assigned to Vuzix Corporation, West Henrietta, NY (US)
Appl. No. 18/009,561
Filed by Vuzix Corporation, West Henrietta, NY (US)
PCT Filed Jun. 9, 2021, PCT No. PCT/US2021/036671
§ 371(c)(1), (2) Date Dec. 9, 2022,
PCT Pub. No. WO2021/252672, PCT Pub. Date Dec. 16, 2021.
Claims priority of provisional application 63/036,758, filed on Jun. 9, 2020.
Prior Publication US 2023/0213770 A1, Jul. 6, 2023
Int. Cl. G02B 27/01 (2006.01); G02B 27/42 (2006.01); G02B 27/44 (2006.01)
CPC G02B 27/0172 (2013.01) [G02B 27/4233 (2013.01); G02B 27/44 (2013.01)] 19 Claims
OG exemplary drawing
 
1. An image light guide for conveying a virtual image, comprising:
a waveguide;
an in-coupling diffractive optic configured to direct image-bearing light beams into said waveguide; and
an out-coupling diffractive optic configured to expand an eyebox in two dimensions and direct at least a portion of said image-bearing light beams from said waveguide toward said eyebox;
wherein said out-coupling diffractive optic comprises a first zone comprising a first set of diffractive features, and a second zone comprising a second set of diffractive features arranged adjacent to said first zone along at least one dimension;
wherein said first set of diffractive features define at least a first grating vector and a second grating vector, and said second set of diffractive features define at least a third grating vector and a fourth grating vector,
wherein said first and third grating vectors are substantially parallel and said second and fourth grating vectors are substantially parallel;
wherein a magnitude of a first diffracted order of said image-bearing light output by said second set of diffractive features defined by said third grating vector is less than a magnitude of the first diffracted order of said image-bearing light output by said first set of diffractive features defined by said first grating vector.