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Ferromagnetography Memory Readout

IP.com Disclosure Number: IPCOM000096412D
Original Publication Date: 1963-May-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 2 page(s) / 43K

Publishing Venue

IBM

Related People

Braun, RE: AUTHOR

Abstract

The magnetic surface 10, which can be magnetic tape, has 1 bit written on it as flux transitions in one direction and has 0 bits written on it as flux transitions in the opposite direction. Thus, a 1 bit is represented on the magnetic surface as an abutment of the north poles of adjacent magnetic domains. A 0 bit is represented by an abutment of south magnetic poles of adjacent magnetic domains. Iron filings or other magnetic particles are placed on surface 10 from dispenser 12 to develop Bitter patterns displaying each bit represented by an abutment of a pair of like magnetic poles. The Bitter pattern appears the same for both 0 and 1 bits in this case.

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Ferromagnetography Memory Readout

The magnetic surface 10, which can be magnetic tape, has 1 bit written on it as flux transitions in one direction and has 0 bits written on it as flux transitions in the opposite direction. Thus, a 1 bit is represented on the magnetic surface as an abutment of the north poles of adjacent magnetic domains. A 0 bit is represented by an abutment of south magnetic poles of adjacent magnetic domains. Iron filings or other magnetic particles are placed on surface 10 from dispenser 12 to develop Bitter patterns displaying each bit represented by an abutment of a pair of like magnetic poles. The Bitter pattern appears the same for both 0 and 1 bits in this case.

On the opposite side of surface 10, structure 14 supports current-carrying lead 13 in a direction parallel-to the pole abutment Bitter pattern lines representing bits. Thus, where several tracks are recorded on surface 10, lead 13 is adjacent to a bit in each track.

A current of one direction through lead 13 provides a flux component perpendicular to pole abutment lines. The flux engaging the magnetic surface is insufficient to erase any recorded bit. However, current in a given direction causes a shift of the Bitter pattern positions in a direction transverse to lead 13. The direction of the shift from lead 13 of any Bitter pattern is dependent upon whether it represents an abutment of north poles or south poles, and, thus, is dependent upon whether the Bitter pattern represents a 0 or 1 bit.

Surface 10 need not be moving at the time that the bit sensing occurs. Thus, pulsing of a...