Static non-destructive single wall domain memory with hall voltage readout

Claim 2

The combination comprising: A. a first sheet of material in which single wall domains can be maintained at determinate stable positions; B. a second sheet of material overlying said first sheet and including a plurality of Hall probe elements each in substantial alignment with one of said determinate stable positions, each of said elements including a pair of spaced electrical control connections in one direction and a pair of spaced electrical sense connections in a direction transverse to said one direction; C. means for providing current to said control connections of certain ones of said elements thereby energizing said certain ones of said elements; and D. means, coupled to said sense connections of selected ones of said elements, for sensing the presence or absence of said single wall domains when certain ones of said elements are energized.

Claim 3

The combination as defined in claim 1 wherein said single wall domains are capable of movement between said determinate stable positions.

Claim 4

The combination as defined in claim 1 wherein: A. each of said elements have said sense terminals thereof coupled in parallel circuit with each other; B. said means for providing current includes means for providing two coincident currents to a predetermined one of said elements thereby producing a first voltage of first polarity at said sense terminals of said predetermined one of said elements when sensing the presence of a single wall domain and producing a second polarity voltage when sensing the absence of a single wall domain; C. said elements receiving only one of said two coincident currents producing a second voltage of first polarity at said sense terminals thereof when sensing the presence of a single wall domain, said second voltage being less than said first voltage, and producing a second polarity voltage when sensing the absence of a single wall domain; and D. said means for sensing adapted to respond to said first voltage but not to said second voltage, nor said second polarity voltage, said responSe indicating the presence of a single wall domain at the position of said predetermined one of said elements receiving said coincident currents.

Claim 5

The combination as defined in claim 1 wherein: A. said Hall probe elements are arranged in a row and column matrix configuration; B. each of said elements have said sense terminals thereof coupled in parallel circuit with each other; C. said means for sensing is adapted to respond to a second voltage of first polarity which is greater than a first voltage, said response to said second voltage indicating the presence of a single wall domain; D. said means for providing current includes a means for providing a first current to a selected row of said elements and a means for providing a second current to a selected column of said elements; E. said first current through one of said elements producing a third voltage at said sense terminals thereof and said second current through one of said elements producing a fourth voltage at said sense terminals thereof, either of said third voltage or said fourth voltage being less than said first voltage; and F. said first and second currents simultaneously provided through one of said elements producing a fifth voltage of first polarity at said sense terminals thereof when sensing the presence of a single wall domain, said fifth voltage being equal to or greater than said second voltage and producing a second polarity voltage at sense terminals thereof when sensing the absence of a single wall domain.

Claim 6

The combination as defined in claim 4 further comprising isolation means coupled in circuit with each of said elements so that only said voltages of first polarity are passed therefrom and to said means for sensing.

Claim 7

The combination as defined in claim 1 wherein: A. said Hall probe elements are arranged in a row and column matrix configuration, said selected ones of said elements included in said columns and said certain ones of said elements included in said rows; B. said means for providing current is coupled to selectively provide current to one of said rows of said elements; and C. said means for sensing includes a plurality of sense circuits each coupled to a column of said elements.

Claim 8

The combination as defined in claim 6 wherein: A. each of said elements included in a row have said control terminals thereof coupled in series circuit with each other and said means for providing current; and B. each of said elements included in a column have said sense terminals thereof coupled in parallel circuit with each other.

Claim 9

The combination as defined in claim 6 wherein: A. each of said elements included in a row have said control terminals thereof coupled in parallel circuit with each other and said means for providing current; and B. each of said elements included in a column have said sense terminals thereof coupled in parallel circuit with each other.

Claim 10

The combination as defined in claim 6 wherein: A. each of said elements included in a row have said control terminals thereof coupled in series circuit with each other and said means for providing current; and B. each of said elements included in a column have said sense terminals thereof coupled in series circuit with each other.

Claim 11

The combination as defined in claim 6 wherein: A. each of said elements included in a row have said control terminals thereof coupled in parallel circuit with each other and said means for providing current; and B. each of said elements included in a column have said sense terminals thereof coupled in series circuit with each other.

Claim 12

The combination comprising: A. a first sheet of magnetic material which is generally magnetized in a particular direction perpendicular to the two surfaces of said sheet and which includes small regions in which the magnetization is in a direction opposite said particular direction; B. a second sheet of material overlYing said first sheet and including a plurality of elements each generating a voltage across opposite edges of said element in response to current applied in a direction substantially transverse said opposite edges when said element is placed in a magnetic field, each of said elements in substantial alignment with one of said regions; C. means for providing current to certain ones of said elements thereby energizing said certain ones of said elements; and D. means for sensing said voltage across said opposite edges of selected ones of said elements.

Claim 13

The combination comprising: A. a first sheet of magnetic material which is generally magnetized in a particular direction perpendicular to the two surfaces of said sheet and which includes small regions in which the magnetization is in a direction opposite said particular direction; B. a second sheet of material overlYing said first sheet and including a plurality of elements each generating a voltage across opposite edges of said element in response to current applied in a direction substantially transverse said opposite edges when said element is placed in a magnetic field, each of said elements in substantial alignment with one of said regions; C. means for providing current to certain ones of said elements thereby energizing said certain ones of said elements; and D. means for sensing said voltage across said opposite edges of selected ones of said elements.