Kabushiki Kaisha Toshiba

Yusuke Ohinata

Yuji Sakai

Hiroaki Yoda

Junichi Akiyama

Masahide Yatsu

Kohichi Tateyama

Norio Nakamura

Akihiro Kimura

Koji Osafune

Kazuhito Shimomura

Nobuyasu Goto

Hiroyuki Naka

Yoshio Horiguchi

According to one embodiment, a disk drive is provided which corrects already existing offset information according to a variation of a disk runout amount caused by an occurrence of a disk shift. The disk drive effects a head position adjustment at a head positioning control time with the use of offset information stored in a memory. A CPU measures a variation in the disk runout amount and phase caused by an occurrence of a disk shift resulting from an external shock involved and updates the existing offset information with a correction offset information based on a result of measurement.

Method and apparatus for head positioning control in a disk drive

In a data-recording mode, a driver circuit supplies a recording head with a recording current corresponding to write data. In a degaussing mode, the driver circuit supplies the recording head with a degaussing current for eliminating the residual magnetism of the head as the recording current. The degaussing current has a rising period and falling period set longer than those of the recording current supplied in the data-recording mode.

Head amplifier circuit with function for degaussing residual magnetism of recording head

A magnetic head is configured by forming a thin-film-shaped magnetic element on top of a thin film that is provided parallel to a medium-facing surface. An aperture is formed in the thin film, and part of a main magnetic pole is formed to have a tip portion that protrudes into that aperture. This configuration makes it possible to impose highly accurate control over the amount by which thin-film-shaped magnetic elements are recessed from the medium-facing surface, while simultaneously exerting accurate control over the amount of protrusion of the main magnetic pole tip portion by making the thickness of the thin film extremely small. As a result, the recording flux strength at the main magnetic pole tip portion can be increased to the ultimate value thereof, making it possible to supply a head that can record on a high retention force medium suitable for higher densities.

Method a fabricating a magnetic head

In a data recording system used for a magnetic disk drive, a write amplifier feeds a write head with a recording current that corresponds to the data to be recorded on the disk. A recording current controller selects a current value to be fed to the write head from the write amplifier according to the recording pattern detected by a pattern detection circuit. Thus, an effective recording track width can be selected without relying on the recording wavelength of the data to be recorded. Therefore, the influence of the cross talk from adjacently located tracks can be effectively reduced without unnecessarily reducing the recording track width.

Magnetic recording control system for disk storage drive

A magnetic disk drive system for writing data into a disk-shaped magnetic medium and reading data stored therein, comprises a first terminal, a second terminal, and at least one third terminal, a composite head unit including an inductive write head and at least one magnetoresistive read head which are connected in series between the first and second terminals, and at least one common connection node connected to the at least one third terminal, and a driving circuit connected to the first through third terminals. The driving circuit includes a write circuit for supplying a write current to the write head, a read circuit for supplying a sense current to the read head to generate a read signal, and a plurality of switches for connecting the write circuit to the write head and electrically disconnecting the read circuit from the composite head unit and the write circuit during writing, and for connecting the read circuit to the read head and electrically disconnecting the write circuit from the composite head unit and the read circuit during reading.

Growing community of inventors

Tachikawa, Japan

Yusuke Ohinata