Dual PDLC-projection head-up display
US5729242A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 8, 1996 |
| Grant date | Mar 17, 1998 |
| Priority date | — |
| Expiry date | May 8, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B2027/012
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An optical system is provided that produces bright, high contrast head-up display images which are not adversely affected by the direct exposure to sunlight of the system's virtual image source. The optical system comprises a light source system which projects a focused light beam to a segmented, electronically-addressed polymer-dispersed liquid crystal ("PDLC")-type film, which serves as a primary image source. Selected segments of the image source are made transmissive while other selected segments scatter light. Accordingly, the portions of the focused light beam incident to transmissive segments are transmitted to form a real image, while the balance of the focused light beam is scattered. A stray light-blocking means, such as a lens/aperture combination, is employed to block the scattered light. The real image is projected onto an unsegmented, electronically-addressed PDLC-type film serving as an image screen. The image screen is the head-up display image source and replaces other emissive light sources in conventional head-up displays. The PDLC-type image screen is unsegmented so that there are no display elements to provide false information upon exposure to sunlight. Moreov…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.