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Magnetic Recording Scanning Method Using a Special Head and Biasing Waveforms

IP.com Disclosure Number: IPCOM000095806D
Original Publication Date: 1964-Jul-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 2 page(s) / 54K

Publishing Venue

IBM

Related People

Braun, RE: AUTHOR

Abstract

Stationary magnetic transducing head 1, shown in perspective at A, records diagonally across magnetic tape 2, viewed in elevation at B. Tape 2 moves in the direction generally indicated by arrow 3. The recording is confined to small localized tape areas by virtue of the special construction of head 1 and the special characteristics of the signals applied to write winding 4.

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Magnetic Recording Scanning Method Using a Special Head and Biasing Waveforms

Stationary magnetic transducing head 1, shown in perspective at A, records diagonally across magnetic tape 2, viewed in elevation at B. Tape 2 moves in the direction generally indicated by arrow 3. The recording is confined to small localized tape areas by virtue of the special construction of head 1 and the special characteristics of the signals applied to write winding 4.

An AC signal 5, shown at C, is applied to winding 4. Signal 5 is varied in amplitude in discrete predetermined steps confined within boundary limits defined by the knees of respective B-H hysteresis curves 6... 8. These characterize the respective tape magnetization characteristics of the head 1 at the respective gaps G1... G3. Under these conditions, the signal of smallest amplitude at 9 is insufficient to saturate tape 2 in either direction in the vicinity of any of G1... G3. The signal amplitude at 10, while sufficient to bidirectionally saturate tape 2 in the vicinity of G1 to effect AC erasure of tape 2 in that vicinity, is insufficient to saturate tape 2 in the vicinity of G2 and G3. The amplitude at 11 is sufficient to effect erasure of the tape in the vicinity of G1 and G2, but insufficient to affect the condition of the tape passing in the vicinity of G3. Hence, the signals 9... 11, without further modification, would have no effect at all on the magnetic condition of an initially erased tape.

If pulse infor...