Rewritable sign system
US6888607B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 29, 2002 |
| Grant date | May 3, 2005 |
| Priority date | — |
| Expiry date | Nov 7, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02F2203/34
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Rewritable signs (100, 1300) that include bistable cholesteric liquid crystal layers (102, 1402, 1404, 1406) are provided. According to one embodiment a rewritable sign (100) is devoid of circuitry for establishing electric fields in localize regions for writing information to the rewritable sign (100), and is consequently inexpensive. In the latter embodiment, a separate information writer (400) that includes an array of pixel electrodes (404) that is driven by an active matrix (602) is used to write information on the rewritable sign. According to another embodiment a rewritable sign (1300) includes three cholesteric liquid layers (1402, 1404, 1406) each of which reflects a different primary color. The three cholesteric liquid crystal layers (1402, 1404, 1406) are interleaved with sets of conductive lines (1316, 1320, 1322, 1324) that are used to apply signals to the cholesteric liquid crystal layers (1402, 1404, 1406) for the purpose of writing information.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.