Outward coupling suppression in waveguide display
US10845526B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 23, 2019 |
| Grant date | Nov 24, 2020 |
| Priority date | — |
| Expiry date | Aug 23, 2039 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F1/163
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A pupil replication waveguide for a projector display includes a slab of transparent material for propagating display light in the slab via total internal reflection. A diffraction grating is supported by the slab. The diffraction grating includes a plurality of slanted fringes in a substrate for out-coupling the display light from the slab by diffraction into a blazed diffraction order. A greater portion of the display light is out-coupled into the blazed diffraction order, and a smaller portion of the display light is out-coupled into a non-blazed diffraction order. A refractive index contrast profile of the diffraction grating along a thickness direction of the diffraction grating is symmetrical, and a refractive index contrast is larger at a middle than at both sides of the refractive index contrast profile, whereby the portion of the display light out-coupled into the non-blazed diffraction order is decreased.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.