Patent · US Expired

Optical recording medium

US4702945A · kind A · utility

34Cited by

2References

5Claims

0Family size

Assignee

BASF SE

Inventors

Karl-Heinz Etzbach · Bischofswerda, DE
Peter Neumann · Wiesloch, DE
Matthias Dust · Ludwigshafen, DE
Helmut Ringsdorf · Mainz, DE
Hans-Werner Schmidt · Bayreuth, DE
Guenter Baur · Glückstadt, DE
Friedrich Windscheid · Schallstadt, DE
Rudolf Kiefer · Denzlingen, DE

Key dates

Filing date	Aug 9, 1985
Grant date	Oct 27, 1987
Priority date	—
Expiry date	Aug 9, 2005

Classification

Technology area (CPC G)Physics
CPC primaryG11B7/248
WIPO fieldAudio-visual technology
WIPO sectorElectrical engineering

Abstract

An optical recording medium contains, on a base, one or more dyes and a polymer which forms liquid-crystalline phases. The information is written into the uniformly oriented liquid-crystalline polymer layer, for example by means of a laser. During this procedure, the polymer heats up locally to above a phase transition temperature. By cooling, the resulting change is frozen in the glass state. The information can be erased by applying an electric field and/or heating. The recording material permits high-contrast storage and possesses high sensitivity, good resolution and excellent stability.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.