International Business Machines Corporation

Tatsuya Endo

Hiroaki Suzuki

Hideo Asano

Akihiko Aoyagi

Kenji Kuroki

Kenji Okada

Akira Kibashi

Takao Matsui

Hiroyasu Tsuchida

Isao Yoneda

Masakazu Sasaki

Makoto Takase

Haruo Andoh

Koji Kurachi

Hiromi Nishimiya

Koichi Arai

Kazuyuki Kobayashi

Hiroshi Terashima

Katsumi Suda

Yoshio Yamamoto

Katsushi Yamaguchi

Hisashi Kakuta

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

An Error Recover Procedure (ERP) is disclosed which, during execution of the ERP, while self-diagnosing the cause of error, dynamically changes the error recovery steps of the ERP. An appropriate ERP is selected and executed according to the detected error status.

Method and device for error recovery

In accordance with the present invention, the initialization for orienting the magnetized directions of the free layers of GMR heads (mounted on the diagonally shaded surface of sliders,) by an external magnetic field is again executed also for the opposite direction, thereby to increase the yield of the GMR heads. Further, it is determined whether the magnetized direction of the pinned layer of GMR heads can be once reversed to the opposite direction, thereby to select damaged GMR heads at an early stage. Then, by performing a reset while performing a quasi-static test for seeing the read back response of the GMR head after restoring the magnetized direction of the pinned layer to a positive rotation, a safe and efficient reset is executed. The reset can be executed not only by applying only a pulse, but also while providing an external magnetic field in the pinning direction, or only by giving a high magnetic field. A tool,can be commonly used for the initialization, reset, or read back response through each process level. For the quasi-static test, coils,, and,are selectively used as Helmholz coils.

Methods for initializing and/or resetting GMR heads by applying oppositely directed magnetic fields

Disk drive and servo pattern write method for preventing read errors

A disk drive apparatus and a method for executing an error recovery process for an error caused by thermal asperity is set forth by positioning a disk read/write head in the vicinity of a thermal asperity and then by vibrating the head so that the head hits the foreign matter or protrusion on the surface of the disk causing the thermal asperity. Vibrations in the longitudinal direction are generated in a head by supplying a vibration signal to VCM. The vibration signal is superimposed on a head driving signal. During the vibration process, the head is positioned on a track shifted from a thermal asperity causing track by several tracks in order to hit the thermal asperity by an edge of a head.

Error recovery method and disk drive apparatus to superimpose a

A load beam for a data storage device having a first end operatively configured for connecting to a head actuator arm and a second end operatively configured for supporting a signal transducer head is provided. The load beam has a flange with a bent portion. The bent portion is arranged by bending the standing portion of the flange in the middle thereof outwardly from the load beam. The bent portion is arranged so that it progressively becomes wider as it runs toward the end of the load beam. The flange is adapted to be nearly flush with a flat base surface at the end of the load beam so as not to have a standing portion and such that signal wires may be connected to a signal transducer head without being unduly bent.

Load beam for supporting a transducer head in a disk drive

A head suspension load beam for a disk file has a slender base portion shaped like a plate, one end of which is secured to a head actuator arm, and the other end of which supports a head. The base portion is reinforced by bending a side margin portion in the longitudinal direction of the base portion at substantially right angles to the plane of the base portion, and further by providing reinforcement ribs, the height of which does not exceed the height of the bent side margin portion, almost parallel to the side margin portion. A head suspension load beam of another embodiment of this invention is reinforced by bending the side margin portion substantially parallel with the plane of the base portion or further toward the plane of the base portion, instead of using reinforcement ribs.

Head suspension load beam with reinforcing ribs

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Fujisawa, Japan

Tatsuya Endo