Other

Irwin Magnetic Systems, Inc.

Brier Technology, Inc.

Michael I Behr

Frank C Bumb, Jr

John F Bizjak

Philip C Kenny

Leonard R Shenfield

William Benson

Scott D Miller

A track means defined by magnetic recording media on a substrate, the media along the track means having two levels, one for recording of data, and the other for recording of servo information, wherein recorded magnetic transitions at the second level define the servo information, the transitions arrayed along the track means as groups of converging lines which extend in crosswise or spanwise relation to multiple tracks. The data is recorded without any wasted magnetic space between tracks (zero guardband) using alternating angles (azimuthal) of magnetic orientation so that they do not interfere with each other when read. The read bead cores or gaps may be 'oriented' to read recorded data transitions extending at different angles relative to track length direction.

Systems using superimposed, orthogonal buried servo signals

A track means defined by magnetic recording media on a substrate, the media along the track means having two levels, one for recording of data, and the other for recording of servo information, wherein recorded magnetic transitions at the second level define the servo information, the transitions arrayed along the track means as groups of converging lines which extend in crosswise or spanwise relation to multiple tracks. The data is recorded without any wasted magnetic space between tracks (zero guardband) using alternating angles (azimuthal) of magnetic orientation so that they do not interfere with each other when read. The read head cores or gaps may be 'oriented' to read recorded data transitions extending at different angles relative to track length direction.

Method of reading and writing data transitions on side-by-side tracks on

Magnetic head structure is operated to record both servo magnetic transitions, and data magnetic transitions, in magnetic media, the servo transitions buried relative to the data transitions, the servo transitions recorded along bands and the data transitions recorded along side-by-side tracks, the bands being wider than the data tracks, the data transitions having lateral lengths greater than track width. The magnetic head structure typically employs multiple magnetic flux servo write gaps, including a leading first gap extending at one angle .alpha. and a trailing second gap extending at an angle .beta., relative to the direction of travel of the media past the head structure, the first and second flux gaps spaced and positioned to span multiple of the data tracks.

System using superimposed, orthogonal buried servo signals

The present invention describes a time based servo pattern scheme which provides position and velocity information with high accuracy. A plurality of servo lines are formed on a data disk extending from the inner track to the outer track. In the preferred embodiment of the present invention, these lines are employed as part of a buried servo scheme such that the entire useable disk surface is dedicated to data storage. The servo pattern is written on each side of the disk so that, if the disk were transparent, the respective servo lines would appear to intersect when viewed from above. Servo heads located on each side of the disk detect servo line crossings. By comparing the time difference between crossings of corresponding tracks on either side of the disk, the radial position of the heads can be determined. Therefore, even when nominal track centers do not fall on servo line intersections, their position can be determined accurately. Thus, the servo pattern of the present invention is track pitch independent. A concentric calibration track is formed on the disk surface so that offsets between the desired servo and data head positions may be detected and compensated.

Method of recording servo signals

The specification discloses a method and apparatus for servo-positioning moveable transducer heads and the like by means of time-based servo system utilizing a particular type of servo pattern or format recorded on a data storage member, e.g., magnetic tape or disk, and having first and second sets of servo lines that extend angularly across the recording media from opposite sides thereof convergently toward one another. The individual lines in each such set of recorded servo information extend alongside one another without intersecting, and in a preferred embodiment the two sets of servo lines intersect along a medial portion of the recording media, to define a uniform series of angles disposed adjacent one another along the recording member, a preferred such pattern having a chevron-like appearance. The overall servo pattern formed by the two sets of servo lines preferably extends across substantially the entire usable surface of the recording media to provide continuous servo-positioning. Data is written over the same surface as the servo pattern, preferably by recording each different type of information in different levels of the recordable media, and preferably at a substantial difference in azimuth angle, whereby read-write isolation between the servo and data is further achieved. The specification also discloses a calibration means comprising a separately-recorded parallel information track by which any offset present between the servo heads and the data heads of individual drives may be determined and utilized in read-write operations to insure complete accuracy in tracking.

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Pasadena, CA, United States of America

Michael I Behr