Optical disk system for recording and reproducing a mini disk and standard compact discs

摘要

In an optical disk recording and reproducing apparatus, audio data compressed in MD format can be recorded on a CD-sized optical disk and can be reproduced from both mini disks and compact disks. A disk for reproducing, in which audio data compressed in MD format is recorded by forming pits on a CD-sized polycarbonate substrate, enjoys a long play back time.