Retro-reflective sign
US6253477A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 23, 1998 |
| Grant date | Jul 3, 2001 |
| Priority date | — |
| Expiry date | Sep 23, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG09F13/16
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A retro-reflective sign is formed of a lens plate bearing indicia and having a front face and a rear face. The rear face is formed with a plurality of adjacent cube corner configurations having central axes, which configurations may reflect light rays approximately parallel to incoming light rays. The front face can be formed with adjacent rows of prisms that are saw-tooth shaped in cross-section. The prisms overlap the configurations and are shaped to bend incoming light rays towards the axes of their respective overlapped configurations and to re-bend the reflected light rays parallel to the incoming light rays. The lens plate is bowed so that its front face is convex and its rear face is concave. A rearwardly bowed support plate covers the rear face of the lens plate and the two plates are secured together along their peripheral edges for rigidifying the sign. The rear plate may be sufficiently light transparent to pass some light therethrough to backlight the indicia on the front plate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.