John M Gorres

US Patent:

41492650, Apr 10, 1979

Filed:

Apr 11, 1977

Appl. No.:

5/786317

Inventors:

John M. Gorres - Cottage Grove MN
Marlin M. Hanson - Cologne MN
Roger E. Lund - Woodbury MN

Assignee:

Sperry Rand Corporation - New York NY

International Classification:

G11C 1908

US Classification:

365 2

Abstract:

A method of and an apparatus for improving the selective positioning of single wall domains or bubble domains in a bubble domain memory system is disclosed. The method includes the use of slotted intersecting digit and word drive lines that form memory areas, each memory area being defined by the inside opposing edges of the slotted drive lines at each intersection. Each memory area has four quadrants, three of which are effectively optically blocked by an opaque shield--a bubble domain in the one unblocked quadrant provides the desired Faraday rotation of a plane polarized coherent light beam to generate a beamlet that is optically detected as a binary digital signal. The slotted drive lines are formed below the surface of the bubble domain supporting layer whereby the so-provided magneto static barriers prevent bubble domain sticking in a selected one quadrant of the four quadrants of the memory area and prevent bubble domain escape from the memory area itself.