For an optical recording medium having a phase change type recording layer on its a substrate and having as read only area and a writable area in a recording area, a data recording method is provided which records data in the writable area. This data recording method comprises a transfer step of transferring...http://www.google.de/patents/US7664000?utm_source=gb-gplus-sharePatent US7664000 - Data erase method for rewritable phase change type recording medium
