Process for reading-out information from electrically polarizable data carriers by means of electron beams
US4785437A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 4, 1985 |
| Grant date | Nov 15, 1988 |
| Priority date | — |
| Expiry date | Dec 4, 2005 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B9/10
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The information recorded in the data carrier in the form of a locally variable electric polarization is scanned and selected by means of an electron beam. For this purpose, the secondary electrons produced on the surface of the data carrier are used. The data carrier is simultaneously either periodically heated by radiating electromagnetic waves or charged with ultrasonics. Potential fluctuations of equal frequency thereby arise on the surface of the data carrier dependent on local polarization, which fluctuations result in a modulation of the secondary electrons. The secondary electron flow thus receives information via the polarization conditions stored in the data carrier. To recover this information, the secondary electron flow is frequency-selectively amplified and electronically evaluated according to amount and/or phase. A polyvinylidene flouride film (PVDF) is preferably used as data carrier.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.