Optical collimating apparatus
US4859031A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 3, 1987 |
| Grant date | Aug 22, 1989 |
| Priority date | — |
| Expiry date | Aug 3, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B2027/0118
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An optical collimating apparatus employs a semi-reflective concave mirror and cholesteric liquid crystal element. In one embodiment, the optical collimating apparatus is used as a heads-up display device. Images in the line of sight of an observer substantially pass through a transmitter/combiner, semi-reflective concave mirror, and cholesteric liquid crystal element to an observer. Images generated by an image source are focussed on the transmitter/combiner such that the transmitter/combiner reflects the images into the line of sight of the observer. The generated images are transmitted by the primarily transmissive (convex) side of the semi-reflective concave mirror to the cholesteric liquid crystal element. The cholesteric liquid crystal element reflects the generated images back toward the primarily reflective (concave) side of the semi-refective concave mirror, which in turn reflects the images back toward the cholesteric liquid crystal element, which transmits the generated images to the observer. In an alternative embodiment, such as in a flight simulator or similar device, an image source projects images upon the primarily transmissive (convex) side of a semi-reflective con…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.