Exit pupil expanding diffractive optical waveguiding device
US10359635B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 14, 2018 |
| Grant date | Jul 23, 2019 |
| Priority date | — |
| Expiry date | Aug 14, 2038 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B2027/0174
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An optical device is disclosed for expanding input light in two dimensions in an augmented reality display. The device comprises a waveguide (12) and three linear diffraction grat-ings H0, H1, H2. An incident beam from a projector illuminates an input grating H0 with polychromatic light, and the light is coupled into the waveguide (12). The other two gratings H1, H2 are overlaid on top of one another. Light can be diffracted by one grating H1 into a first diffracted order and towards the other grating H2 which can couple the light out of the waveguide (12) towards a viewer. In another arrangement the crossed gratings H1, H2 may be replaced by a photonic crystal (19) having a regular array of pillars (20) which create a number effective diffraction gratings.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.