Optical system for image transmission, particularly for projection devices of the head-mounted type
US7477453B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 27, 2006 |
| Grant date | Jan 13, 2009 |
| Priority date | — |
| Expiry date | Apr 25, 2027 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B2027/012
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An optical system for image projection, particularly for projection devices of the “head-mounted”type, includes a display, an optical system for focusing an image formed by the display, and a light guide having an extended body, with two opposite, longitudinal, plane and parallel faces, and opposite ends which define first reflecting surface for coupling into the light guide and second reflecting surface for extracting the image from the light guide. Each light ray which propagates through the light guide undergoes at least three internal total reflections on the parallel plane faces of the light guide. At least a surface of the focusing optical system is a portion of a surface free of rotational symmetry axes. Moreover, the two reflecting surfaces of the light guide are portions of surfaces free of rotational symmetry axes. Finally, the inlet pupil of the light guide coincides with the outlet pupil of the focusing system.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.