Vuzix Corporation
WAVEGUIDE TURNING GRATING DESIGNS FOR OPTIMAL EFFICIENCY

Abstract:

An imaging apparatus includes an in-coupling diffractive optic directs image-bearing light beams into a planar waveguide, an out-coupling diffractive optic directs the image-bearing light beams from the waveguide toward a viewer eyebox, and a turning diffractive optic directs the image-bearing light beams along the waveguide between the in-coupling and out-coupling diffractive optics. The grating vectors of the in-coupling and out-coupling diffractive optics differ in magnitude and orientation while the grating vectors of all three diffractive optics sum to substantially zero. The turning diffractive optic is further arranged to preserve a desired angular relationship of the propagating image bearing beams within the waveguide.