Hitachi, Ltd.

Eiji Nakanishi

Kazuo Shiiki

Shinji Narishige

Hiroshi Sakurai

Shigeru Tadokoro

Hirotsugu Fukuoka

Norifumi Miyamoto

Masanori Tanabe

Hiroshi Daito

Toshio Suzuki

Yukihiro Isono

Mikio Takahashi

Tetsuya Matsusaki

Sunao Yonekawa

Kouichi Shimizu

Mitsuo Suda

Kiyoji Morita

Masao Matsushita

Masato Furusaki

Protrusion of head elements to an air bearing surface is effectively reduced and their contact with a recording medium is thereby prevented by forming a level gap (concave) of about 3 nm in a multilayered protective film on the air bearing surface in a part matching an inductive write thin film head in a recording/reproducing separated type magnetic head and thereby offsetting protrusion of the head elements to the air bearing surface due to thermal deformation of the heads.

Recording/reproducing separated magnetic head with concave portion formed in air bearing protective film

In a magnetic disk device having a composite head with an induction type of recording head adjacent a magneto-resistance effect type of reproducing head, a read error relief is provided to relieve read errors caused by Barkhausen Noise or Base Line Shift phenomenon inherent to the magneto-resistance effect type of reproducing head. Upon occurrence of a read error, a re-try function is first executed, and a track offset function is executed for relief of the read error. However, if the read error is not relieved after the offset operation and the re-try operation have been performed a predetermined number of times, then a pseudo write-in and/or read current control operation is performed together with the offset operation and/or re-try operation for a predetermined number of times. The control operation varies the magnetic domain structure in the head magnetic film (MR film). The variation of magnetic field and/or read current in the head magnetic film causes the magnetic domain structure of the head magnetic film to be varied, so that the Barkhausen Noise or the Base Line Shift phenomenon are extinguished.

Magneto-resistance effect type of recording/reproducing head

A magnetic disk apparatus has a disk assembly including a single servo disk and a plurality of data disks, a servo-head supporting structure for supporting a servo head and data-head supporting structures for supporting data heads. These heads are so disposed as to cooperate with respective disks. The servo-head and data-head supporting structures are driven by an actuator to move the servo head and the data heads to the required positions on the corresponding disks. The servo-head supporting structure and each of the data-head supporting structures have different proper oscillations to prevent the occurrence of a resonance during a seek operation.

Magnetic disk apparatus with head supporting structures of different

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Minami-ashigara, Japan

Eiji Nakanishi