Waveguides
US8493662B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Sep 7, 2009 |
| Grant date | Jul 23, 2013 |
| Priority date | — |
| Expiry date | Feb 16, 2030 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B6/0038
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A waveguide 60 formed of material 62 allows propagation of image bearing light along a light pathway 64 by total internal reflection of the image bearing light. The layer of material 62 is a light transparent material arranged to allow an observer, not illustrated, to look through the layer of material 62 whilst also arranged to carry image bearing light. A grating element 66 carried within the layer of material 62 is arranged such that impinging image bearing light following the light pathway 64 is either diffracted out of the layer of material 62 as a pupil of image bearing light 68a to 68n or is reflected by either surface 70 or surface 72. The efficiency of the grating element 66 is varied along the length of the layer of material 62 to achieve the desired pupils of image bearing light 68a to 68n along the length of the layer of material 62. This results in a more even brightness of pupils of image bearing light 68a to 68n, as perceived by the observer looking through the layer of material 62.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.