Erasable flat recording medium - has carrier with sheet material whose optical state changes reversibly with temp. changes and writing-erasing criteria code on carrier

摘要

The erasable sheet recording medium in sections consists of a carrier with a sheet applied to it which changes optical states reversibly when its temp. increases from a first, e.g. room temp. to a second and then a third temp. The carrier (T) is dark coloured on the sheet (S) side and has a rough surface. A machine readable code applied to the other side of the carrier is read and evaluated before writing, printing and/or erasing. USE/ADVANTAGE - Ensures that recording and erasing only take place according to defined criteria contained in code.