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Browse Prior Art Database

Cylindrical Magnetic Domain Random Access Memory

IP.com Disclosure Number: IPCOM000074289D
Original Publication Date: 1971-Apr-01
Included in the Prior Art Database: 2005-Feb-23
Document File: 2 page(s) / 28K

Publishing Venue

IBM

Related People

Genovese, ER: AUTHOR [+2]

Abstract

Information represented by the presence and absence of cylindrical magnetic domains is electrically written into selected locations in this random access memory. Optical read-out is used.

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Cylindrical Magnetic Domain Random Access Memory

Information represented by the presence and absence of cylindrical magnetic domains is electrically written into selected locations in this random access memory. Optical read-out is used.

A shows the system in which a magnetic sheet 10 is capable of supporting cylindrical magnetic domains. Located above sheet 10 is conductor loop pattern 12, shown in more detail in Fig. B. Drivers 14 are connected to pattern 12.

The optical reading system comprises laser 16, light deflector 18, rotating mirror 20, analyzer 22, and photosensitive detector 24. Since cylindrical domains affect the polarization of input light, detector 24 is responsive to the presence and absence of a cylindrical domain at any location.

Fig. B shows the conductor loop patterns which are used to nucleate and collapse domains in sheet 10. Drivers 14 provide current pulses along row conductors X1, X2, X3...and also along column conductors Y1, Y2, Y3... These sets of conductor loops are orthogonal to one another and a bit site is defined by the intersection of the loops. For instance, to write a "1" bit into location 2-2, current is applied through X2 and Y2 so that the resultant magnetic field normal to sheet 10 is sufficient to nucleate a domain at that location. In a similar way, two negative currents in X2 and Y2 will collapse a domain located in position 2-2.

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