A composite read-only and rewritable type optical disc, and a disc drive apparatus for reading/writing data into the disc. The optical disc has a plurality of sectors forming a data read-only area and a write/read area. The disc includes a recording film formed over its entire surface by which data can...http://www.google.de/patents/US5173886?utm_source=gb-gplus-sharePatent US5173886 - Composite optical disc having both a data read-only area and a data rewritable area, and a recording/reproducing system for use therewith
