Thin Film Media for Hard Disks

Magnetic disk storage devices are normally used as the main on-line files for information processing systems. Particulate disk media have been primarily used for this purpose. In 1982, however, a magnetic disk storage system which employs thin film disk media having an areal recording density of 24 kbits/mm² was developed. In addition, small hard disk drives mounting thin film disk media 3 ~ 5 inches in diameter are currently being utilized in personal computers and intelligent data terminals. This review summarizes recent developments in this film disk media for longitudinal and perpendicular recording, mainly with respect to the design of read/write operations. The problems to be solved beforehigh areal recording densities and high reliability can be achieved are also considered.