公开(公告)号：DE3275670D1

公开(公告)日：1987-04-16

申请号：DE3275670

申请日：1982-06-18

Applicant: IBM

Inventor： BETTS ALAN JOHN ,  ELLIOTT PETER JAMES

IPC: G11B21/10 ,  G05D3/12 ,  G11B5/596 ,  G11B5/58

公开(公告)号：DE3277601D1

公开(公告)日：1987-12-10

申请号：DE3277601

申请日：1982-06-18

Applicant: IBM

Inventor： BETTS ALAN JOHN ,  ELLIOTT PETER JAMES

IPC: G11B5/596 ,  G11B21/10 ,  G11B5/58

Abstract: The disk is divided into data sectors each of which has several concentric tracks. Servo sectors are interspersed with the data sectors. The servo sectors contain position reference information, which define radial position of the data tracks for an associated head positioning servo system. The position reference information comprises a circumferentially extending and radially repeated magnetisation pattern with radial offset subsets of elements. From each subset s different phase of radial position error signal is derived. The error signal indicates a displacement from a data track centre line. The radial offset from each other of the subsets of elements is less than the pitch of the data tracks. Each individual element has a radial width greater than the pitch of a data track.

公开(公告)号：SG42857A1

公开(公告)日：1997-10-17

申请号：SG1996000188

申请日：1991-12-12

Applicant: IBM

Inventor： JAMES DAVID THOMAS ,  LEONARD ANTHONY WILLIAM ,  ELLIOTT PETER JAMES

IPC: G11B5/706 ,  G11B5/738 ,  G11B5/596 ,  G11B5/55

Abstract: A novel magnetic recording disc is provided comprising, a nonmagnetic support having thereon a nonmagnetic layer comprising nonmagnetic particles and a binder resin, and a magnetic layer comprising ferromagnetic particles and a binder resin, in this order. The nonmagnetic particles in the nonmagnetic layer are partially or entirely electrically conductive particles, the thickness of the magnetic layer is in the range of 0.5 mu m or less, and the orientation ratio of the ferromagnetic particles in the magnetic layer is 0.85 or more. A novel process for preparing the magnetic recording disc is provided. Further, a novel process for recording and reproduction of a signal having a shortest recordable wavelength of 1.5 mu m or less is provided, which utilizes the magnetic recording disc in conjunction with a magnetic head having a gap length ( delta ) of 0.50 mu m or less.

公开(公告)号：DE69127086T2

公开(公告)日：1998-02-12

申请号：DE69127086

申请日：1991-12-12

Applicant: IBM

Inventor： JAMES DAVID THOMAS ,  LEONARD ANTHONY WILLIAM ,  ELLIOTT PETER JAMES

IPC: G11B5/596 ,  G11B20/12 ,  G11B27/30 ,  G11B33/10 ,  G11B33/12 ,  G11B5/55

Abstract: A clock track is written inside a sealed head disk assembly (HDA) using a Monte Carlo technique. The clock track is read by a magneto-optical head 300 through a window 350 in the HDA housing, and using the time transitions therefrom to control the product heads, the entire servo pattern for the disk drive can be written with the HDA unit completely sealed.

公开(公告)号：DE69127086D1

公开(公告)日：1997-09-04

申请号：DE69127086

申请日：1991-12-12

Applicant: IBM

Inventor： JAMES DAVID THOMAS ,  LEONARD ANTHONY WILLIAM ,  ELLIOTT PETER JAMES

IPC: G11B5/596 ,  G11B20/12 ,  G11B27/30 ,  G11B33/10 ,  G11B33/12 ,  G11B5/55

Abstract: A clock track is written inside a sealed head disk assembly (HDA) using a Monte Carlo technique. The clock track is read by a magneto-optical head 300 through a window 350 in the HDA housing, and using the time transitions therefrom to control the product heads, the entire servo pattern for the disk drive can be written with the HDA unit completely sealed.