Page Memories Patents (Class 365/235)
  • Patent number: 4149265
    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.
    Type: Grant
    Filed: April 11, 1977
    Date of Patent: April 10, 1979
    Assignee: Sperry Rand Corporation
    Inventors: John M. Gorres, Marlin M. Hanson, Roger E. Lund