Quarter-wave film for brightness enhancement of holographic thin taillamp
US5745266A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 2, 1996 |
| Grant date | Apr 28, 1998 |
| Priority date | — |
| Expiry date | Oct 2, 2016 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S385/901
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A holographic thin rear exterior lamp for a vehicle including a light pipe (11) having first and second opposing surfaces (11a, 11b), a rear exterior lamp hologram (13, 113) attached to one of the first and second surfaces of the light pipe, a polarization rotating retarder film (16, 116) attached to one of the first and second opposing surfaces oppositely from the rear exterior lamp hologram, a light source (17, 19) for providing a substantially collimated beam, a transmission hologram (15) disposed on one of the first and second surfaces of the light pipe for coupling the substantially collimated beam into the light pipe such that a portion of the substantially collimated light propagates by total internal reflection within the light pipe, the rear exterior lamp hologram and the polarization rotating retarder film. The polarization rotating retarder film is configured to impart a substantially halfwave retardance to internally reflected light that passes twice therethrough.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.