Multimedia type digital audio disc system

The authors have developed a multimedia DAD (digital audio disc) CD (compact disc), a write-once-type disc, and an MO (magnetooptical) disc. To realize this system, they developed an overwrite function on the MO disc that uses the magnetic field modulation method and system control techniques for the compatibility of three types of discs. The DAD system has a recording time of more than 70 min. The optical head, MO disc, magnetic head, read/write characteristics, and player system are discussed.<
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