公开(公告)号：DE3065686D1

公开(公告)日：1983-12-29

申请号：DE3065686

申请日：1980-08-21

Applicant: IBM

Inventor： ARTER NELSON KAY ,  DEVORE ERNEST WILLIAM ,  WILLS ARTHUR BARTON ,  ZELENKA LESLIE RAY

IPC: G11B5/55 ,  G11B5/008 ,  G11B5/012 ,  G11B5/09 ,  G11B5/265 ,  G11B5/53 ,  G11B15/087 ,  G11B15/12 ,  G11B15/60 ,  G11B20/12 ,  G11B23/00 ,  G11B27/30 ,  G11B27/32 ,  G11B5/02 ,  G11B5/52 ,  G11B5/27

Abstract: A data recorder/reader provides forward/backward compatibility with record members of similar physical characteristics, but differing data record track densities. In a rotating head, helical tape recorder/reader, a single head 16 has a wide write gap 17 followed by a pair of aligned half width read gaps 18 and 19. During recording at high track density, the tape is stepped between recordings by drive 27 under the control of half step circuit 29 for a distance equal to half the width W2 of the write gap and to the width W1 of each read gap. During recording at low track density, the tap is stepped between recordings by drive 27 under the control of whole step circuit 28 for a distance equal to the width W2 of the write gap. Switching between circuits 28 and 29 is effected by pole 54 of switch S1. During read back at high density, two adjacent tracks are sensed simultaneously by read gaps 18 and 19. Signals are fed back to individual read back circuits 31 and 37, those from the first read gap 18 being passed through switch 43 to data circuit 33 for immediate processing. Signals from the second read gap 19 are passed to a buffer 39 and buffered until a dead time occurs when no data is being sensed. The switch 43 is then operated to direct the buffered signals to data circuit 33 for processing. Between read backs, the tap is stepped by drive 27 under the control of whole step circuit 28 for a distance equal to the width W2 of the write gap. Circuit 28 is selected through pole 54 of switch S1 and pole 49 of switch S2. During read back at low track density, a single wide track is sensed simultaneously by read gaps 18 and 19. Signals from the first read gap 18 are processed immediately. Signals from the second read gap 19 may be inhibited or buffered for later processing in data circuit 33 in the event of error correction being required. Between read backs, the tape is stepped for a distance equal to the width W2 of the write gap.

公开(公告)号：DE2432259A1

公开(公告)日：1975-04-10

申请号：DE2432259

申请日：1974-07-05

Applicant: IBM

Inventor： BROCK GEORGE WILLIAM ,  SHELLEDY FRANK BOYD ,  SMITH SIDNEY HENRY ,  WILLS ARTHUR BARTON

IPC: G11B5/33 ,  G11B5/39 ,  G11B5/30 ,  G11B5/28

Abstract: A magnetoresistive (MR) head with an unusually desirable spatial resolution includes a shield on each side of the MR element. Information is carried on a magnetizable medium as recorded magnetic areas. The shields are spaced apart by a distance on the order of and less than the shortest recorded wavelength for which the head is meant to be used. The MR element and the shields have their edges nearest the medium in a common plane perpendicular to the vertical component of a signal from the recorded area. An additional shunt bias layer may be provided immediately adjacent and coextensive the MR element, and the head may serve one or many tracks.

公开(公告)号：DE2239583A1

公开(公告)日：1973-03-29

申请号：DE2239583

申请日：1972-08-11

Applicant: IBM

Inventor： CHOW TSENG KAN ,  WILLS ARTHUR BARTON

IPC: G11B5/10 ,  G11B5/48 ,  G11B15/58 ,  G11B15/64 ,  G11B5/26