公开(公告)号：DE69125447T2

公开(公告)日：1997-09-25

申请号：DE69125447

申请日：1991-09-06

Applicant: IBM

Inventor： BROWN DANA HENRY ,  CUNNINGHAM EARL ALBERT ,  ERICKSON KEVIN JACK ,  ESTRY RICHARD HUNT ,  GLASER THOMAS WILLIAM ,  HAGEN MARK DAVID ,  OTTESEN HAL HJALMAR ,  PALMER DEAN CURTIS ,  STEPHENSON JOHN JEFFREY

IPC: G11B5/48 ,  G11B5/55 ,  G11B5/596 ,  G11B7/08 ,  G11B21/02 ,  G11B21/08 ,  G11B5/265

Abstract: Disclosed is an apparatus and method for correcting for track misregistration when a slider or head assembly contains a separate read element (40) and write element (42). Basically, the offset is determined at a first position and at a second position of the actuator arm (48) assembly. From these offsets a constant and a multiplier are determined for determining an offset as a function of the cylinder location. Also disclosed is a method and apparatus for minimizing distance traveled to prevent misregistration when repositioning between the read element and a write element. The read element is intentionally offset from the write element at an angle so as to minimize the distance traveled across the disk.

公开(公告)号：DE3750315D1

公开(公告)日：1994-09-08

申请号：DE3750315

申请日：1987-05-19

Applicant: IBM

Inventor： CHRISTENSEN THOMAS CHARLES ,  JAWORSKI RICHARD CASIMIR ,  COKER JONATHAN DARREL ,  KERWIN GREGORY JOHN ,  CUNNINGHAM EARL ALBERT ,  PALMER DEAN CURTIS ,  ROEPKE JEFFREY RALPH

IPC: G11B5/09 ,  G11B5/00 ,  G11B5/012 ,  G11B5/035 ,  G11B5/455 ,  G11B20/18 ,  G11B27/36

Abstract: A magnetic disk drive channel circuitry is shown and described that generates eight incremental values of write current and eight incremental values of delta-V (the minimum voltage change per unit time which tests signals to discriminate between data and noise). Each of these variable parameter values may be program selected by a three bit bus signal. This variability testing of and adaptation to the optimum parameter value for each head media combination and by grouping tracks in contiguous data bands, the parameters may be optimized for tracks near the inner diameter, the outer diameter and in the middle band. The variable delta-V can also be used as an additional data recovery tool wherein re-reading with a lower value enhances recovery of missing bit errors and re-reading with an increased value can assist recovery from an extra bit error.

公开(公告)号：SG46192A1

公开(公告)日：1998-02-20

申请号：SG1996000419

申请日：1991-09-06

Applicant: IBM

Inventor： BROWN DANA HENRY ,  CUNNINGHAM EARL ALBERT ,  ERICKSON KEVIN JACK ,  ESTRY RICHARD HUNT ,  GLASER THOMAS WILLIAM ,  HAGEN MARK DAVID ,  OTTESEN HAL HJALMAR ,  PALMER DEAN CURTIS ,  STEPHENSON JOHN JEFFREY

IPC: G11B5/48 ,  G11B5/55 ,  G11B5/596 ,  G11B7/08 ,  G11B21/02 ,  G11B21/08 ,  G11B5/265

Abstract: Disclosed is an apparatus and method for correcting for track misregistration when a slider or head assembly contains a separate read element (40) and write element (42). Basically, the offset is determined at a first position and at a second position of the actuator arm (48) assembly. From these offsets a constant and a multiplier are determined for determining an offset as a function of the cylinder location. Also disclosed is a method and apparatus for minimizing distance traveled to prevent misregistration when repositioning between the read element and a write element. The read element is intentionally offset from the write element at an angle so as to minimize the distance traveled across the disk.

公开(公告)号：DE69125447D1

公开(公告)日：1997-05-07

申请号：DE69125447

申请日：1991-09-06

Applicant: IBM

Inventor： BROWN DANA HENRY ,  CUNNINGHAM EARL ALBERT ,  ERICKSON KEVIN JACK ,  ESTRY RICHARD HUNT ,  GLASER THOMAS WILLIAM ,  HAGEN MARK DAVID ,  OTTESEN HAL HJALMAR ,  PALMER DEAN CURTIS ,  STEPHENSON JOHN JEFFREY

IPC: G11B5/48 ,  G11B5/55 ,  G11B5/596 ,  G11B7/08 ,  G11B21/02 ,  G11B21/08 ,  G11B5/265

Abstract: Disclosed is an apparatus and method for correcting for track misregistration when a slider or head assembly contains a separate read element (40) and write element (42). Basically, the offset is determined at a first position and at a second position of the actuator arm (48) assembly. From these offsets a constant and a multiplier are determined for determining an offset as a function of the cylinder location. Also disclosed is a method and apparatus for minimizing distance traveled to prevent misregistration when repositioning between the read element and a write element. The read element is intentionally offset from the write element at an angle so as to minimize the distance traveled across the disk.

公开(公告)号：DE3750315T2

公开(公告)日：1995-03-09

申请号：DE3750315

申请日：1987-05-19

Applicant: IBM

Inventor： CHRISTENSEN THOMAS CHARLES ,  JAWORSKI RICHARD CASIMIR ,  COKER JONATHAN DARREL ,  KERWIN GREGORY JOHN ,  CUNNINGHAM EARL ALBERT ,  PALMER DEAN CURTIS ,  ROEPKE JEFFREY RALPH

IPC: G11B5/09 ,  G11B5/00 ,  G11B5/012 ,  G11B5/035 ,  G11B5/455 ,  G11B20/18 ,  G11B27/36

Abstract: A magnetic disk drive channel circuitry is shown and described that generates eight incremental values of write current and eight incremental values of delta-V (the minimum voltage change per unit time which tests signals to discriminate between data and noise). Each of these variable parameter values may be program selected by a three bit bus signal. This variability testing of and adaptation to the optimum parameter value for each head media combination and by grouping tracks in contiguous data bands, the parameters may be optimized for tracks near the inner diameter, the outer diameter and in the middle band. The variable delta-V can also be used as an additional data recovery tool wherein re-reading with a lower value enhances recovery of missing bit errors and re-reading with an increased value can assist recovery from an extra bit error.

公开(公告)号：DE3370091D1

公开(公告)日：1987-04-09

申请号：DE3370091

申请日：1983-11-29

Applicant: IBM

Inventor： CUNNINGHAM EARL ALBERT ,  PALMER DEAN CURTIS

IPC: G11B5/09 ,  G11B5/02 ,  G11B5/58 ,  G11B5/584 ,  G11B5/596 ,  G11B20/20

Abstract: Method of recovering data from a track (T2) that has been obscured or overlapped as a result of adjacent track misregistration or head sensitivity to the low frequency content of adjacent tracks (T1, T3). The method includes the steps of reading and storing the information from the adjacent tracks (T1, T3) and thereafter erasing the adjacent tracks (T1, T3) either on centerline (CL1, CL3) or with the transducer offset toward the intermediate track (T2) of interest. The track of interest (T2) can then be read with the transducer aligned with the track centerline (CL2) and at varying positions of offset. If this sequence of rereads fails, the erase step can be repeated with greater amounts of offset toward the intermediate track (T2) to further reduce inband interference and the reread sequence also repeated.