公开(公告)号：JPH087203A

公开(公告)日：1996-01-12

申请号：JP13983794

申请日：1994-06-22

Applicant: IBM

Inventor： SONOBE YOSHIAKI ,  UCHIDA HIROSHI ,  TOYOOKA TAKASHI ,  MATSUI TAKAO ,  AOKI TATSUJI ,  IIHARA YASUHIRO ,  TSUCHIMOTO KAZUNARI ,  OZAWA YUTAKA

IPC: G11B5/39 ,  G11B5/02

Abstract: PURPOSE: To enhance easily the stability of a magnetic domain of a MR head without carrying out complicated works such as disassembling and assembling etc. and reproduce data. CONSTITUTION: A drive device 28 is driven corresponding to a signal output from a controller body 40 of a HDC 30, and it records and reproduces data in a location where an access arm is pivoted at a specific angle. When data for this disk are recorded and reproduced, a bias current supplied to a reproduction element 21A of a magnetic head 20A having a MR effect is turned on/off only for a specific period by a reproduction control circuit 32A. Accordingly, as a direction of a magnetizing vector is changed within a specific period, a magnetic domain of the reproduction element 21A (MR element) is not unstable, but stabilized so that data from the disk can be reproduced stably.

公开(公告)号：JPH0737216A

公开(公告)日：1995-02-07

申请号：JP15500793

申请日：1993-06-25

Applicant: IBM

Inventor： KIGAMI YUJI ,  MATSUI TAKAO ,  KURACHI KOJI ,  OSAWA TOYOZO

IPC: G11B5/09 ,  G11B5/48 ,  G11B20/12 ,  G11B27/30

Abstract: PURPOSE: To improve a reading error rate on identification(ID) information in a sector servo type magnetic disk device provided with a head having a separated reading element and writing element. CONSTITUTION: One pair of ID fields 21a and 21b for recording ID information are set in each sector of each track of the magnetic disk. This one pair of ID fields are mutually separated in the direction along the track and radially deviated each other by the distance equivalent to the radial direction offset between the reading element 24 and writing element 23 related to the track. The magnetic head is positioned so as to read ID information in the ID field 21b with the reading element 23 at the time of a data writing operation on an optional track. The head is positioned so as to read ID information in the ID field 21a with the reading element 23 at the time of a data reading operation on the track.

公开(公告)号：JPH11238212A

公开(公告)日：1999-08-31

申请号：JP4025598

申请日：1998-02-23

Applicant: IBM

Inventor： TSUNAKO KAZUJI ,  AMANO YOSHIRO ,  MATSUI TAKAO ,  MIURA TAKESHI

IPC: G11B5/09 ,  G11B5/012 ,  G11B5/02 ,  G11B5/40 ,  G11B5/48 ,  G11B33/12 ,  H05K1/02 ,  H05K1/18

Abstract: PROBLEM TO BE SOLVED: To enhance the electrostatic discharge resistance of a device without degrading the high frequency characteristic of the device by amplifying the detection output of a magneto-resistance effect type sensor whose one end is grounded and connecting a nonlinear conductive element in between a power source voltage line supplying a power source voltage and a grounding line. SOLUTION: A varistor 30 is provided in between a power source voltage line supplying a power source voltage and a grounding line on a control substrate 20. Moreover, on the substrate 20, a capacitor 31 is provided in parrallel with the varistor 30 and, further, an inductance 32 inserted in series with the power source voltage line is provided. The varistor 30 has a capacitive component and the capacitive component, the capacitor 31 and the inductance 32 function as a low-pass filter eliminating noise being on the power source voltage line. Thus, a high frequency component being in a power source voltage to be supplied to an AE7 is reduced and they contribute to the stable operation of the AE7. Furthermore, the miniatirizing of the capacitor 31 is made possible by the capacitance of the varistor 30.

公开(公告)号：JPH11191201A

公开(公告)日：1999-07-13

申请号：JP35689697

申请日：1997-12-25

Applicant: IBM

Inventor： SUZUKI HIROMASA ,  KURACHI KOJI ,  SUDA KATSUMI ,  ASANO HIDEO ,  OKADA KENJI ,  TAKASE MAKOTO ,  KIHASHI AKIRA ,  NISHINOMIYA HIROMI ,  MATSUI TAKAO ,  ENDO TATSUYA ,  KUROKI KENJI

IPC: G11B5/02 ,  G11B5/09 ,  G11B5/39 ,  G11B5/455 ,  G11B19/04 ,  G11B20/18

Abstract: PROBLEM TO BE SOLVED: To improve the performance of an information recording/reproducing device using a GMR(giant magnet resistance) sensor. SOLUTION: This method aims at the restoration of an operating error generated in an information recording/reproducing device including a storage medium, a head using a GMR sensor, an actuator arm for mounting the head and locating the head on a prescribed position on the front surface of the storage medium and a control part for controlling the operation of the actuator arm and read/write operation. At this time, it comprises a step for executing a first error restoring procedure 103, a step for executing a first GMR evaluating procedure 109 for evaluating the performance of the GMR sensor when the operating error is not restored in the first error restoring procedure and a step 117 for impressing a reset pulse to the GMR sensor in accordance with the first GMR evaluating procedure.

公开(公告)号：JPH07320247A

公开(公告)日：1995-12-08

申请号：JP10876294

申请日：1994-05-23

Applicant: IBM

Inventor： MATSUI TAKAO ,  OGASAWARA KENJI

IPC: G11B5/39 ,  G11B5/012 ,  G11B5/48 ,  G11B5/55 ,  G11B5/56 ,  G11B5/596 ,  G11B19/04

Abstract: PURPOSE: To inhibit the quantity of an offtrack of a reproducing element within a range moving in a magnetic head by positioning the reproducing element of the magnetic head so as to be equalized from the center of a track. CONSTITUTION: The sorting of processing by a magnetic head 20A to a disk 18A is set first. A positioning method refers to a map first. A skew angle is read. The quantity of a micro-Jog in either processing of set skew angle and data recording processing, data reproducing processing and format processing as objects is set. An access arm 22A is driven in response to the quantity of the micro-jog set. Accordingly, since the micro-jog is distribute within a linear range from the quantity of an offtrack at a time when the offtrack from a track center to one side is conducted by a reproducing element to the quantity of another offtrack and an MR head is positioned, the characteristics of the reproducing element having an MR effect can be utilized maximally and effectively.

公开(公告)号：JP2001243611A

公开(公告)日：2001-09-07

申请号：JP2000047042

申请日：2000-02-24

Applicant: IBM

Inventor： SUZUKI HIROMASA ,  UMEMURA KAORU ,  SHIBATA AKIRA ,  ENDO TATSUYA ,  MATSUI TAKAO ,  IKEDA MASAOMI ,  HASHIMOTO JUNJI

IPC: G11B5/00 ,  G11B5/012 ,  G11B5/48 ,  G11B5/596 ,  G11B21/10

Abstract: PROBLEM TO BE SOLVED: To reduce reproduction errors by improving the setting accuracy of a reproduction offset generated between the recording head and the reproducing head of a compound type head part. SOLUTION: The recording head records a test pattern on a plurality of tracks to be measured (S2), the amplitude of a regenerative signal by the reproducing head is measured at a plurality of different tracking positions about the respective tracks to be measured (S5), the approximate expression of a profile of the measured amplitude with respect to the tracking positions is found (S6), a position where a maximum value is given in the approximate expression is calculated as a tracking position at which the amplitude of the regenerative signal is maximum, a reproduction offset is calculated on the basis of the tracking position with the maximum amplitude (S7), and the reproduction offset of an optional track is set in a disk device on the basis of the reproduction offset about the tracks to be measured (S10).