Waveguides
US8369019B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 25, 2009 |
| Grant date | Feb 5, 2013 |
| Priority date | — |
| Expiry date | May 22, 2029 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B2027/0125
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A projection display (60) includes a first waveguide (64) incorporating a grating structure (74) and second waveguide (66) incorporating an exit grating (84). The first and second waveguides (64, 66) are arrange to expand an image in orthogonal directions. The second waveguide (66) includes a first layer (86) with a first predetermined refractive index and/or first predetermined thickness, a second layer (88) with a second predetermined refractive index and/or second predetermined thickness. The exit grating (84) is arranged to direct at least some impinging light out of the second waveguide(66) and to provide at least some beam splitting of light passing through the exit grating (84). The first and second layers (86, 88) are arranged to abut one another such that the exit grating (84) is therebetween. The first predetermined refractive index and second predetermined refractive index and/or first predetermined thickness and second predetermined thickness are arranged to vary the spatial periodicity of pupils of image bearing light radiated from the second waveguide (66).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.