Retroreflective articles and devices having viscoelastic lightguide
US8651720B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 26, 2009 |
| Grant date | Feb 18, 2014 |
| Priority date | — |
| Expiry date | Mar 9, 2030 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B6/0063
- WIPO fieldOther consumer goods
- WIPO sectorOther fields
Abstract
Disclosed herein is an optical device having a light source, a viscoelastic lightguide and a retroreflective film suitable for retroreflecting light. Light from the light source enters the viscoelastic lightguide and is transported within the lightguide by total internal reflection. The transported light is extracted from the lightguide and retroreflected at a structured surface of the retroreflective film. The optical device may have a “front lit” or a “back lit” configuration depending on the relative positioning of the lightguide and the retroreflective film. The retroreflective film may include prismatic retroreflective sheeting, holographic film or film structured with diffraction gratings. The optical device may be used, for example, as a sign or marking, a license plate assembly, a tail light assembly for vehicles, a security laminate for protection of documents against tampering, or an illumination device.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.