Heads-up display combiner utilizing a cholesteric liquid crystal element
US4900133A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 27, 1988 |
| Grant date | Feb 13, 1990 |
| Priority date | — |
| Expiry date | Oct 27, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B2027/0118
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A heads-up display (HUD) system employs a cholesteric liquid crystal combiner, an image source, and collimating optics to combine a generated image with an image in an observer's field of view. The cholesteric liquid crystal combiner has a bandwidth, B, around a primary wavelength of maximum reflection, and the image source projects its images within bandwidth B for high efficiency of reflection. Outside bandwidth B the cholesteric combiner has a high efficiency of transmission. Images from the image source are projected upon the combiner which reflects the images toward the observer, together with images from the outside environment in the line-of-sight of the observer. Collimating optics are used to focus the projected images at a distance away from the observer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.