公开(公告)号：AU6812090A

公开(公告)日：1991-07-18

申请号：AU6812090

申请日：1990-12-17

Applicant: IBM

Inventor： BEST JOHN STEWART ,  HETZLER STEVEN ROBERT ,  KABELAC WILLIAM JOHN ,  THOMPSON DAVID ALLEN

IPC: G11B5/584 ,  G11B5/596 ,  G11B20/12 ,  G11B21/10

Abstract: A method and means is described for writing data on a recording medium, such as a disk or tape, containing servo samples in such manner that the number of servo samples is increased with a minimal increase in overhead (non-data) regions. The tracks on the medium are divided into a plurality of maxi sections, each of which contains all fields with servo and associated overhead information and also a data field. At least one micro servo section containing only a portion of said information is located within each data field. As each micro servo section passes by an associated recording head, writing and reading of data is temporarily interrupted, but resumed when the micro servo section moves beyond the head, in such manner as to require minimal resynchronisation of said data during reading. Using a phase continuous clock, data is written in both portions of a data field to either side of each micro servo section in one pass of the disk or tape relative to the head. The micro servo sections contain no timing reference address mark and require no data encoder/decoder flush or synchronisation byte to resume reading in the portion of the data field following each micro servo section.

公开(公告)号：DE3168655D1

公开(公告)日：1985-03-14

申请号：DE3168655

申请日：1981-10-05

Applicant: IBM

Inventor： GARWIN RICHARD LAWRENCE ,  THOMPSON DAVID ALLEN ,  SCRANTON ROBERT ALAN ,  WORTHINGTON THOMAS KIMBER

IPC: G11B5/54 ,  G11B5/55 ,  H02K41/02 ,  H02K41/035

公开(公告)号：IT8025316D0

公开(公告)日：1980-10-14

申请号：IT2531680

申请日：1980-10-14

Applicant: IBM

Inventor： ROMANKIW LUBOMYR TARAS ,  THOMPSON DAVID ALLEN

IPC: G11B5/31 ,  H04R

Abstract: A thin film inductive transducer head includes a magnetic circuit with a pair of legs and inductive coils. The legs are thinner near the pole tip than in the back gap region. The legs are also narrower in the pole tip region than in the back gap region. Resolution is enhanced by the thin pole tips and saturation of the yoke structure is avoided by increasing the cross-sectional area of the yoke structure away from the pole tip region.

公开(公告)号：DE2849536A1

公开(公告)日：1979-06-21

申请号：DE2849536

申请日：1978-11-15

Applicant: IBM

Inventor： THOMPSON DAVID ALLEN

IPC: G11C11/02 ,  G11C11/12 ,  G11C21/00 ,  H01L41/12 ,  H01L41/22 ,  G11C11/06

Abstract: A device includes a core, such as a wire or cylinder of a solid material such as nonmagnetic metal, coated with a film of a material having a high degree of magnetostriction and a uniaxial helical magnetic anisotropy at an oblique angle to the longitudinal axis of the core. The device has the characteristic of being magnetically bistable and of providing a large magnetic pulse as it changes to one of its stable states in response to passage of a magnetic field by it. To achieve a helical magnetic anisotropy, the magnetostrictive film can be applied to a nonmagnetic wire by plating the wire while it is under torsion, twisting a plated wire after plating, or by applying an electric current and a magnetic field to the wire as the film is being plated or annealed.

公开(公告)号：DE2620657A1

公开(公告)日：1977-02-10

申请号：DE2620657

申请日：1976-05-11

Applicant: IBM

Inventor： MAZZEO NICKOLAS JOSEPH ,  THOMPSON DAVID ALLEN

IPC: G11C11/14 ,  G01R15/14 ,  G01R33/02 ,  G01R33/09 ,  G11B5/37 ,  G11B5/39 ,  G11C19/08 ,  H01H36/00 ,  G11B5/30

Abstract: A thin film magnetoresistive sensor of NiFeCo is juxtaposed with a saturable thin film shield of more highly permeable NiFe material. The curve depicting change of resistance of the sensor as a function of applied magnetic field is flattened, permitting the sensor to provide a magnetic switch, such as a keyboard transducer, a sensor of current through wires, a magnetic bubble detector and a remote control scanning sensor in a recording head. The scanner involves a stepped arrangement for providing different levels of sensitivity for adjacent sections of the magnetoresistive sensor.

公开(公告)号：DE2262659A1

公开(公告)日：1973-07-12

申请号：DE2262659

申请日：1972-12-21

Applicant: IBM

Inventor： THOMPSON DAVID ALLEN

IPC: G11B5/31 ,  G01T1/115 ,  G11B5/39 ,  G11B5/12

公开(公告)号：DE69108418T2

公开(公告)日：1995-10-12

申请号：DE69108418

申请日：1991-01-17

Applicant: IBM

Inventor： BEST JOHN STEWART ,  HETZLER STEVEN ROBERT ,  KABELAC WILLIAM JOHN ,  THOMPSON DAVID ALLEN

IPC: G11B5/584 ,  G11B5/596 ,  G11B20/12 ,  G11B21/10

Abstract: A method and means is described for writing data on a recording medium, such as a disk or tape, containing servo samples in such manner that the number of servo samples is increased with a minimal increase in overhead (non-data) regions. The tracks on the medium are divided into a plurality of maxi sections, each of which contains all fields with servo and associated overhead information and also a data field. At least one micro servo section containing only a portion of said information is located within each data field. As each micro servo section passes by an associated recording head, writing and reading of data is temporarily interrupted, but resumed when the micro servo section moves beyond the head, in such manner as to require minimal resynchronisation of said data during reading. Using a phase continuous clock, data is written in both portions of a data field to either side of each micro servo section in one pass of the disk or tape relative to the head. The micro servo sections contain no timing reference address mark and require no data encoder/decoder flush or synchronisation byte to resume reading in the portion of the data field following each micro servo section.

公开(公告)号：PE28991A1

公开(公告)日：1991-10-29

申请号：PE18008391

申请日：1991-01-08

Applicant: IBM

Inventor： THOMPSON DAVID ALLEN ,  BEST JOHN STEWART ,  KABELAC WILLIAM JOHN ,  HTZLER STEVEN ROBERT

IPC: G11B27/00 ,  G11B5/584 ,  G11B5/596 ,  G11B20/12 ,  G11B21/10

Abstract: SE DESCRIBE UN METODO Y UN MEDIO PARA GRABAR INFORMACION EN UN DISCO O CINTA QUE CONTIENEN SERVOMUESTRAS DE MODO QUE EL NUMERO DE ESTAS SE INCREMENTE MINIMAMENTE EN LAS REGIONES DE NO DATOS (OVERHEAD) LAS PISTAS DEL MEDIO DE GRABACION ESTAN DIVIDIDAS EN UNA PLURALIDAD DE SECCIONES Y CADA UNA DE ESTAS CONTIENE LOS CAMPOS DE IDENTIFICACION (ID) Y SERVO, CON INFORMACION DE NO DATOS (OVERHEAD) Y UN CAMPO DE DATOS

公开(公告)号：DE3583831D1

公开(公告)日：1991-09-26

申请号：DE3583831

申请日：1985-06-03

Applicant: IBM

Inventor： SCRANTON ROBERT ALAN ,  THOMPSON DAVID ALLEN

IPC: G01R27/26 ,  G01D5/24 ,  G01H11/02 ,  G01H11/06 ,  G01N27/22 ,  G11B5/31 ,  G11B5/48 ,  G11B5/58 ,  G11B5/596 ,  G11B5/60 ,  G11B9/07 ,  G11B21/21 ,  G11B9/06

Abstract: The top drawing shows a magnetic head structure having means for detecting small capacitive variations which can be processed to give positional information about the head. The head comprises a substrate 32 carrying pole pieces and their associated pick-up coil 38 and contact pads 36, 37. The detecting means comprise a coil 26 providing an inductive reactance which is connected between a ground pad 23 and a capacitive pick-up electrode 24. The coil is inductively coupled to input arrangement 27 and to output arrangement 28. The other drawings show the equivalent circuit diagram. In use of the structure an oscillator is coupled to the input arrangement 27 and suitable circuitry connected to output arrangement 28 to detect amplitude modulation of the signal induced therein. These modulations provide information about the detected capacitive variations.

公开(公告)号：IT1149831B

公开(公告)日：1986-12-10

申请号：IT2131880

申请日：1980-04-11

Applicant: IBM

Inventor： THOMPSON DAVID ALLEN ,  WORTHINGTON THOMAS KIMBER

IPC: G01D5/48 ,  G06F3/02 ,  G06F3/033 ,  G06F3/043 ,  H03M

Abstract: A magnetoacoustic system adapted to use as a keyboard can employ a serpentine acoustic delay line passing under a number of transducers which are activated simultaneously with a current pulse through the wire. Magnets adjacent to the wire generate magnetoacoustic pulses along the wire which arrive sequentially at a sensor at one end of the line. For each key on a keyboard at least two magnets are associated with each key position with one magnet affixed in position and one reciprocably movable towards and away from the wire in a response to actuation of the key. The magnet which remains close to the wire is used to provide a "location" signal indicating the location along the delay line provided by the wire by producing an acoustic pulse for that point on the wire for each clock pulse of current which passes through the wire. The second magnet located adjacent to the first magnet generates a pulse simultaneously with the other magnets when the current pulse passes through the wire, but it is delayed by the physical displacement along the wire, so it is received at a different time than the pulse from the other magnet. The data pulse can follow or precede the location pulse so long as the presence of one or both can be readily decoded. A three magnet key arrangement can be employed where it is desired to be able to use three positions per key.