公开(公告)号：JP2003091948A

公开(公告)日：2003-03-28

申请号：JP2001286861

申请日：2001-09-20

Applicant: IBM

Inventor： YAMAZAKI MASAHIDE ,  OZAWA YUTAKA

IPC: G11B21/08 ,  G11B5/55 ,  G11B21/10

Abstract: PROBLEM TO BE SOLVED: To solve a 'connection problem' when a mode is switched and contradiction between short seek and long seek in positioning control of a head. SOLUTION: A gain in feedback control is fluctuated when switching a prescribed control mode when the head is transferred and positioned at an access position by the feedback control.

公开(公告)号：JPH11126443A

公开(公告)日：1999-05-11

申请号：JP27709697

申请日：1997-10-09

Applicant: IBM

Inventor： KISAKA MASASHI ,  OZAWA YUTAKA ,  TSUCHIMOTO KAZUNARI

IPC: G11B20/12 ,  G06F3/06 ,  G06F12/00 ,  G11B5/55 ,  G11B19/02 ,  G11B21/08

Abstract: PROBLEM TO BE SOLVED: To provide a disk drive, disk control method, data reading/writing method, data arranging method, and a disk-like storage medium, which are capable of preventing a nonlinear movement or the increase of the friction of a bearing even though the width of one track becomes further narrower. SOLUTION: In the magnetic disk 11 of a disk drive device 10, LBAs(logical block addresses) are read/written in such a manner that a 1st track including a specified number of continuous LBAs, a 2nd track including a specified number of continuous LBAs in succession of the specified number of continuous LBAs, and at least one track between the 1st track and 2nd track are provided when n pieces of LBAs are included per one track, and in a control part 22, the seek operation is carried out so that the track to read/write the next data is to be the track separated more than one track at least when the continuous data are read/written by moving the track.

公开(公告)号：JP2001195851A

公开(公告)日：2001-07-19

申请号：JP2000007318

申请日：2000-01-17

Applicant: IBM

Inventor： KITAZAKI NOBUYUKI ,  OGASAWARA KENJI ,  YONEDA ISAO ,  OZAWA YUTAKA

IPC: G11B21/08 ,  G11B5/596 ,  G11B19/28 ,  G11B20/14 ,  G11B21/10 ,  G11B19/247

Abstract: PROBLEM TO BE SOLVED: To surely and stably detect servo information even if a disk shift occurs and the time intervals between servo sectors fluctuate. SOLUTION: The time intervals TS (i) after the servo sector in a servo region SF (i) passes under a read/write head before the servo sector in the next servo region SF (i+1) passes under the read/write head are calculated (step S6) in accordance with the internal variable value proportional to the displacement Δr(i) in the disk diametral direction of the servo region SF (i) calculated from already detected servo information and the time intervals to detect the servo information are regulated in accordance with the time intervals TS (i) (steps S7 and S4).

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：JP2001291346A

公开(公告)日：2001-10-19

申请号：JP2000093351

申请日：2000-03-30

Applicant: IBM

Inventor： TOGA KENJI ,  OZAWA YUTAKA ,  KISAKA MASASHI

IPC: G11B21/08 ,  G11B5/55 ,  G11B19/28 ,  G11B21/10 ,  G11B19/14 ,  G11B19/247

Abstract: PROBLEM TO BE SOLVED: To control the position of a head section to a prescribed target position even if the position detecting data of the head section by servo information is not obtainable and to downsize a disk device. SOLUTION: This disk device has a disk (1) which is the recording medium of the data, a spindle motor (2) which rotates the disk, disk rotating speed control means (61 and 62) which supply the spindle current (Ispn) for rotating the disk at a constant speed to the spindle morter, a head section 3 which accesses to the disk, an actuator which moves the head section and head position control means (63-66 and 75) which control the position of the head section (3) by driving the actuator. The head position control means described above acquire the value of the spindle current and control the position of the head section in accordance with the spindle current value by utilizing the changing of the spindle current which varies according to the position changing of the head section.

公开(公告)号：JP2001273707A

公开(公告)日：2001-10-05

申请号：JP2000089857

申请日：2000-03-28

Applicant: IBM

Inventor： KISAKA MASASHI ,  OZAWA YUTAKA ,  TOGA KENJI

IPC: G11B19/04 ,  G11B21/12 ,  G11B25/04 ,  G11B33/08 ,  G11B19/02

Abstract: PROBLEM TO BE SOLVED: To obtain superior recording reliability for a rotary storage device that utilizes a high density recording medium under the environment in which shock or vibration exists. SOLUTION: The device has a means which outputs a shock out signal SO when an output from an acceleration sensor exceeds a prescribed threshold value, a latch circuit 21 which outputs a high level latch signal during a prescribed write inhibit interval after the signal SO is inputted, a write gate signal WG which outputs a high level signal when a write approval is given and an AND circuit 23 which generates a write approval signal when a NOT output of the latch signal and the signal WG are inputted.

公开(公告)号：JP2003109335A

公开(公告)日：2003-04-11

申请号：JP2001289307

申请日：2001-09-21

Applicant: IBM

Inventor： OZAWA YUTAKA

IPC: G11B21/10 ,  G11B5/55

Abstract: PROBLEM TO BE SOLVED: To provide a data storage device capable of performing a track tracking operation even with respect to vibrations of a wide frequency with high accuracy. SOLUTION: A comparator decides whether or not the phase of an output signal of a digital peak filter coincides with the phase of a PES (position error signal) (step S103 of figure 8). If the phase of the output signal of the digital peak filter coincides with the phase of the PES, the frequency of the output signal of the digital peak filter is faster than that of the PES. Therefore, the set frequency of the digital peak filter is lowered (step S107 of figure 8). On the other hand, if the phase of the output signal of the digital peak filter does not coincide with the phase of the PES, the frequency of the output signal of the digital peak filter is slower than that of the PES. Therefore, the set frequency T of the digital peak filter is increased (step S105 of figure 8).