METHOD FOR MULTILEVEL RECORDING INFORMATION ON A RECORD CARRIER, A RECORD CARRIER AND A RECORDING DEVICE

摘要

A record carrier comprises three layers that react with each other when irradiated to form a mark on the record carrier. The three layers are separated by a two separating layers that prevent direct contact of the three layers thus providing stability to the record carrier. By irradiating one or both separating layers a region of those separating layers is destroyed or altered whereby an opening is created and the reaction of the layers adjacent to the separating layer is no longer prevented in that region and a mark can be formed. Since either one or two reactions can take place if one or both separating layers are destroyed or altered multiple reflection levels for a mark can be obtained, thus enabling multilevel recording where a single mark can represent more information compared to the situation where only two reflection levels can be obtained. The size of the resulting opening determines the size of the mark and can thus be used to create a very small mark allowing high density recordings.