High-Density 3.5-inch Optical Disk System for Multimedia
Yoshio Suzuki, Multimedia Systems R & D Division, Hitachi, Ltd.
Masaaki Kurebayashi, Multimedia Systems R & D Division, Hitachi, Ltd.
Seiji Yonezawa, Ph. D., Multimedia Systems R & D Division, Hitachi, Ltd.
Yukio Fukui, Multimedia Systems R & D Division, Hitachi, Ltd.
The demand for data storage devices for multimedia, which integrates audio, video, communications and broadcast with the computer as the core, has been increasing in recent years. Hard disk drives for recording devices and compact disc read-only memory (CD-ROM) for read-only devices are chiefly used now for multimedia. Until now different media have been used for different applications.
However, in accordance with the increase in the amount of data which an individual user manages, an integrated medium which can support multimedia is becoming necessary. It must be a removable medium which equals a hard disk in capacity and transfer rate, and can be distributed in large quantities like a CD-ROM.
In view of this background, we developed a high density optical disk system based on new concepts to support multimedia of the future. This new system has a high transfer rate, and a capacity of 650 Mbyte, the same as the CD-ROM, despite its small 3.5 inch size. In addition, ROM and RAM areas can exist together on a single disk.