Passively illuminated, eye-catching display for traffic signs
US6897786B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 14, 2000 |
| Grant date | May 24, 2005 |
| Priority date | — |
| Expiry date | Mar 2, 2021 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B26/02
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Low-cost, low energy, programmable and remotely activatable traffic signs, particularly suitable for roadside, waterside or comparable use, which signs can display a variety of messages or images, for example warnings and directions, employ electropolymeric shutter arrays in front of retroreflective materials (32). The signs employ daylight or other passive illumination external to the sign, such as vehicle headlights, to yield high contrast images with good visibility. Optional features include attention-getting effects such as flashing, economical solar power means and means to detect vehicle approach to initiate the attention-getting display, e.g. flashing.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.