Hitachi, Ltd.

Kousuke Fujii

Atsushi Ito

Hiroshi Nishida

Tatsuya Ishigaki

Hiroshi Katou

Yoshinobu Kudou

Masahiko Sato

Tetsuzo Kobashi

Norikazu Takayama

Nobuyoshi Ushijima

Yoshihiko Yano

Jun Isozaki

Yoshinobu Kudoh

A magnetic disk apparatus has a base member and a cover mounted on the base member to form an enclosure having at least six magnetic disks rotatably supported therein. First and second transducers are included for writing information on and reading information from upper and lower surfaces of adjacent ones of the magnetic disks. The transducers are supported by leaf springs in close proximity to both surfaces of adjacent ones of the magnetic disks. The leaf springs extend in a radial direction with respect to the magnetic disks and are supported on one end by a plurality of head arms. The leaf springs are arranged substantially within the same plane parallel to the magnetic disks so they do not overlie one another. A voice coil motor is provided for moving the head arms in order to position the transducer pairs in predetermined positions. A circuit board is included for controlling the magnetic disk apparatus.

A magnetic disk apparatus and a motor securement therefor

Magnetic disk apparatus having at least six magnetic disks

A method of forming servo information in a magnetic disk apparatus of a sector servo system. Servo information is recorded in advance at the beginning of each of the sectors, and includes a DC erase signal, a track address signal and a burst signal. The track address signal indicates on which track of the magnetic disk the sector is located, and is formed by expressing the track address in Gray code and interleaving a dummy code into the Gray code. Servo information is recorded using an NRZI system or an RLL coding method. Servo information in which the dummy code is interleaved is decoded after the dummy code is removed at the time of demodulation.

Magnetic disk apparatus

Growing community of inventors

Koganei, Japan

Kousuke Fujii