Information recording/displaying card
US6580481B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 2, 1999 |
| Grant date | Jun 17, 2003 |
| Priority date | — |
| Expiry date | Jul 2, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02F1/13718
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
The invention provides an information recording/displaying card and an information recording/displaying system using the card in which invisible information can be recorded, the invisible information can be displayed as visible information and visible information can be written/erased as color images at a practical speed. The information recording/displaying card includes a visible information display part and an invisible information recording part. These parts are disposed, for example, on the front and back surfaces of the card, respectively, or arranged side by side on the front or back surface thereof. The visible information display part includes, as a main component, a low molecular weight cholesteric liquid crystal compound having an isotropic phase transition temperature higher than a melting point, so that information can be displayed, written once and erased therein. The invisible information recording part is, for example, a magnetic recording layer, a write-once optical recording layer or an integrated circuit memory, in which information can be recorded and erased.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.