Head-up display system where polarized light from a display impinges on a glass plate containing twisted nematic liquid crystal at the plate's Brewsters angle
US5510913A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Jul 20, 1993 |
| Grant date | Apr 23, 1996 |
| Priority date | — |
| Expiry date | Jul 20, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B2027/0194
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A head-up display system for a vehicle includes a front windshield, a display, a polarizing member and an optical rotatory film. The display for displaying an image on the front windshield to be viewed by a driver of the vehicle is disposed such that light therefrom is incident on the front windshield at an angle which is substantially equal to Brewster's angle. The polarizing member is disposed between the front windshield and the display for polarizing light from the display. The optical rotatory film serves to rotate the plane of polarization of light polarized by the polarizing member. The optical rotatory film installed on the front windshield includes a liquid crystal high polymer which is in twisted nematic orientation under liquid crystal condition and is in glassy condition at a temperature which is lower than liquid crystal transition point. Thus, double image problem can be eliminated with respect to light having a wide range of wavelengths.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.