International Business Machines Corporation

Katsumi Suda

Isao Yoneda

Kenji Ogasawara

Kazushi Tsuwako

Fujio Harako

Michio Nakajima

Hiroaki Suzuki

Hideo Asano

Kenji Kuroki

Kenji Okada

Takashi Nakamura

Akira Kibashi

Makoto Takase

Takao Matsui

Yuji Yokoe

Tatsuya Endo

Koji Kurachi

Hiromi Nishimiya

A method and apparatus for recovering from operation errors arising in an information recording and reproducing unit using a head with a GMR sensor is described. The read and write operations of the unit comprise executing a first error recovery procedure for recovering the operation error, executing a first GMR evaluation procedure for evaluating the performance of the GMR sensor when the operation error cannot be recovered by the first error recovery procedure, and applying a resetting pulse to the GMR sensor in accordance with the first GMR evaluation procedure.

Error recovery in unit using GMR sensor

A disk drive apparatus and read error recovery method in a disk drive apparatus removes thermal asperities on disk surfaces. A projection, such as a thermal asperity, on the recording surfaces of disks is detected when a signal transducer head contacts the projection. The flying height of the signal transducer head is lowered, e.g., by changing the disk rotation speed from the normal rotation speed in read/write operations or by heating a suspension having a bimetal element, while the signal transducer head is positioned over the detected projection on the track. The signal transducer head strikes the projection to break the projection. This avoids a subsequent error from being caused by the thermal asperity.

Disk drive apparatus and read error recovery method in a disk drive

A disk drive apparatus and read error recovery method in a disk drive apparatus removes thermal asperities on disk surfaces. A projection, such as a thermal asperity, on the recording surfaces of disks is detected when a signal transducer contacts the projection. The flying height of the signal transducer is lowered, e.g., by reducing the disk rotation speed from the normal rotation speed in read/write operations, while the signal transducer is positioned over the detected projection on the track. The signal transducer strikes the projection to break the projection. This avoids a subsequent error from being caused by the thermal asperity.

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Sagamihara, Japan

Katsumi Suda