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：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：CA1233247A

公开(公告)日：1988-02-23

申请号：CA506445

申请日：1986-04-11

Applicant: IBM

Inventor： JEN SHEN ,  KABELAC WILLIAM J

IPC: G11B5/596 ,  G11B21/10

Abstract: An improved servo control system for data track following of the read/write head in a magnetic recording system uses a pattern of segments of servo information slanted across the data tracks. The time of flight of the servo segment from occurrence of a reference pulse until the peak servo signal is read by the head is an indication of the position of the head in a direction perpendicular to the desired track. This time is compared with the known time of flight if the head were precisely over the centerline of the desired track and the time difference is used to generate a control signal to position the head over the track centerline. In an embodiment where each segment is slanted across only one track, the reference pulse is the beginning of the servo signal and the time measurement is the number of fixed frequency magnetic transitions read by the head in the servo segment. When the system is used in flexible disk drives, the servo segments are written in one of the data sectors on the flexible disk by the user's disk drive.

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.