公开(公告)号：JP2000207727A

公开(公告)日：2000-07-28

申请号：JP35777399

申请日：1999-12-16

Applicant: IBM

Inventor： AHLERT RICHARD H ,  JAMES KENT HOWARD ,  LAMBERT STEVEN E ,  SANDERS IAN L

IPC: G11B5/673 ,  G11B5/64 ,  G11B5/65 ,  G11B5/66 ,  G11B5/716 ,  G11B5/738

Abstract: PROBLEM TO BE SOLVED: To reduce inherent medium noise significantly under a high line recording density by employing a laminate structure of a relatively thin CoPt alloy magnetic film or a CoNi alloy magnetic film separated by a relatively thin nonmagnetic spacer film. SOLUTION: Surface of a substrate is cleaned by RF discharge and a lower layer (300-400 Å thick) of Mo, Cr or CrV is attached by sputtering before being laminated with a magnetic layer. Subsequently, a magnetic layer (magnetic film and spacer) is attached through sputtering by changing the sputtering source to form a laminate structure. Effect of lamination on a signal is minimized and noise reduction is enhanced significantly as the number of laminated films increases. A laminate structure CoPt alloy disc thus produced exhibits excellent low noise characteristic as compared with a single thick CoPt alloy film.

公开(公告)号：JPS61214207A

公开(公告)日：1986-09-24

申请号：JP28321185

申请日：1985-12-18

Applicant: IBM

Inventor： JEN SHEN ,  KABELAC WILLIAM J ,  SANDERS IAN L

IPC: G11B5/596 ,  G11B21/10

公开(公告)号：CA1220270A

公开(公告)日：1987-04-07

申请号：CA499459

申请日：1986-01-13

Applicant: IBM

Inventor： JEN SHEN ,  KABELAC WILLIAM J ,  SANDERS IAN L

IPC: G11B15/087

Abstract: An improved magnetic recording disk drive, in particular a flexible disk drive, includes a head positioning servo system which utilizes servo information recorded on the disk by the disk drive. The servo information is located within one of the data sectors and is in the form of a pattern of radially spacedapart segments, each segment overlapping a number of data tracks and comprising magnetic transitions which increase in frequency in the radial direction to provide a digital head position error signal (PES). A similar segment is located in each of the other data sectors around the perimeter of the disk to provide track profile information so that the head positioning system can compensate for disk runout and distortion. The disk drive includes means for eliminating the effect of the amplitude of the readback signal from the servo and profile segments on the head positioning system, thus assuring a reliable PES at all radial locations on the disk and allowing interchangeability of disks among disk drives.

公开(公告)号：DE3663754D1

公开(公告)日：1989-07-06

申请号：DE3663754

申请日：1986-03-11

Applicant: IBM

Inventor： JEN SHEN ,  KABELAC WILLIAM JOHN ,  SANDERS IAN L

IPC: G11B5/596 ,  G11B21/10 ,  G11B5/016

Abstract: Servo information is located within one of the data sectors of a record disk and is in the form of a pattern of radially spaced-apart segments (51, 52, 53, 61, 62, 63) , each segment overlapping a number of data tracks and comprising magnetic transitions which increase in frequency with distance from the centre of the disk to provide a digital head position error signal (PES). A similar segment (31, 32, 33) is located in each of the other data sectors around the perimeter of the disk to provide track profile information so that a head positioning system can compensate for disk runout and distortion. The disk drive can include means for eliminating the effect of the amplitude of the readback signal from the servo and profile segments on the head positioning system, thus ensuring a reliable PES at all radial locations on the disk and allowing interchangeability of disks among disk drives.

公开(公告)号：CA1181845A

公开(公告)日：1985-01-29

申请号：CA403567

申请日：1982-05-21

Applicant: IBM

Inventor： BEST JOHN S ,  SANDERS IAN L

IPC: G11C11/14 ,  G11C19/08 ,  G11C17/00

Abstract: GAP TOLERANT MERGE ELEMENT FOR CONTIGUOUS-DISK BUBBLE DEVICES A gap tolerant merge element for contiguous-disk bubble devices is disclosed. The merge element includes one input track with a tip portion substantially facing the cusp portion of a second input track to form a merge region. An output track is associated with the merge region. In a preferred embodiment, the merge element is passive and does not have a conductor. In another embodiment, the merge element is active and does have a conductor.