Magnetic thin film shift register having bidirectional transmission elements and offset block sites

Claim 2

Magnetic logic apparatus for operation as a shift register of binary information, said apparatus comprising A. a magnetic domain tip propagation transmission path extending in a forward direction from an input port to an output port, said path being arranged with an alternate succession of spaced-apart first locations and second locations, and a block site associated with each location and disposed forward of the associated location by less than one-half the minimum spacing between adjacent locations, B. means for producing a first magnetic field for propagating magnetic domains along said path, C. means for producing a second magnetic field for removing magnetic domains from said path except at said first locations, and for producing a third magnetic field for removing magnetic domains from said path except at said second locations, and D. means for producing a domain propagation-blocking fourth magnetic field at each block site.

Claim 3

Magnetic logic apparatus as defined in claim 1 further comprising control means for operating said field producing means to produce said first field and, after a selected time delay, to produce said fourth field to continue at least for as long as said first field.

Claim 4

Magnetic logic apparatus as defined in claim 2 in which said control means operates said field producing means in a cycle successively to produce said first and fourth fields to propagate domains forward along said path by only one location, to produce said second field, to produce said first and fourth magnetic fields again to propagate magnetic domains forward along said path by only one location, and to produce said third magnetic field.

Claim 5

Magnetic logic apparatus as defined in claim 1 further comprising control means for operating said field producing means to produce said fourth field throughout the production of said first field except for an offset time corresponding to the average of the times requires for a domain to expand from a location to the next adjacent block sites in both directions along said path with said first field present.

Claim 6

Magnetic logic apparatus as defined in claim 1 further comprising control means for operating said field producing means to produce said fourth field throughout the production of said first field except for a selected time immediately preceding termination of said first field, said selected time corresponding to the time required for a domain to expand along said path between a block site and the associated hold location with said first field present.

Claim 7

Magnetic logic apparatus as defined in claim 1 in which A. said transmission path extends substantially longitudinal to a first axis, B. said means for producing said first magnetic field includes at least a first current conductor that produces said first magnetic field directed longitudinal to said first axis, and C. said means for producing said second and third magnetic fields includes said first current conductor and a second current conductor weaving back and forth across said path transverse to said first axis to produce at each location a magnetic field directed along said first axis, said magnetic fields of said second current conductor being directed at said first locations opposite to the direction thereof at said second locations.

Claim 8

Magnetic logic apparatus as defined in claim 6 in which said means for producing said fourth magnetic field includes a third current conductive structure having current conducting portions crossing said path transversely to said first axis for producing said fourth field in opposition to said first field at each said block site.

Claim 9

In a magnetic domain tip propagation shift register having a domain path with alternate serially-arranged first locations and second locations and extending in a forward direction from an input port to an output port and having means for propagating domains along said path and for erasing domains from said path except at selected locations, the improvement comprising A. block conductors transversely crossing said path for producing domain propagation-blocking magnetic fields therein, said block conductors producing said propagation-blocking fields localized at block sites, one of which is located along said path forward of each location by a distance less than one-half the inter-location spacing, and B. means for energizing said block conductors to produce said blocking fields at a selected time after initiation of each propagation of domains along said path, said time being longer than the time required for domains to propagate forward from a location to beyond the first adjacent block site and being shorter than the time required for domains to propagate backward from a lcoation to beyond the first adjacent block site in that direction.

Claim 10

In a magnetic domain tip propagation shift register having a domain path with alternate serially-arranged first locations and second locations and extending in a forward direction from an input port to an output port and having means for propagating domains along said path and for erasing domains from said path except at selected locations, the improvement comprising A. block conductors transversely crossing said path for producing domain propagation-blocking magnetic fields therein, said block conductors producing said propagation-blocking fields localized at block sites, one of which is located along said path forward of each location by a distance less than one-half the inter-location spacing, and B. means for energizing said block conductors to produce said blocking fields at a selected time after initiation of each propagation of domains along said path, said time being longer than the time required for domains to propagate forward from a location to beyond the first adjacent block site and being shorter than the time required for domains to propagate backward from a lcoation to beyond the first adjacent block site in that direction.

Claim 11

Magnetic logic apparatus for operation as a shift register of binary information, said apparatus comprising A. a magnetic domain tip propagation transmission path extending between first and second terminal ports, said path being arranged with an alternate succession of first and second domain-holding locations, and a block site associated with each location and spatially offset therefrom in a first direction along said path by less than one-half the minimum spacing between adjacent locations, B. means for producing a first magnetic field for propagating magnetic domains along said path, C. means for producing a second magnetic field for removing magnetic domains from said path except at said first locations, and for producing a third magnetic field for removing domains from said path except at said second locations, D. means for producing a domain propagation-blocking fourth magnetic field at each block site, and E. control means for operating said field-producing means to produce said fourth field throughout the production of said first field except for an offset time corresponding to the average of the times required for a domain to expand from a location to the next adjacent block sites in both directions along said path.

Claim 12

Magnetic logic apparatus for operation as a shift register of binary information, said apparatus comprising A. a magnetic domain tip propagation transmission path extending between first and second terminal ports, said path being arranged with an alternate succession of first and second domain-holding locations, and a block site associated with each location and spatially offset therefrom in a first direction along said path by less than one-half the minimum spacing between adjacent locations, B. means for producing a first magnetic field for propagating magnetic domains along said path, C. means for producing a second magnetic field for removing magnetic domains from said path except at said first locations, and for producing a third magnetic field for removing domains from said path except at said second locations, D. means for producing a domain propagation-blocking fourth magnetic field at each block site, and E. control means for operating said field-producing means to produce said fourth field throughout the production of said first field except for an offset time corresponding to the average of the times required for a domain to expand from a location to the next adjacent block sites in both directions along said path.

Claim 13

Magnetic logic apparatus as defined in claim 1 in which A. said means for producing said first magnetic field includes a first current conductor positioned relative to said transmission path for producing said first magnetic field longitudinal to the forward direction of said transmission path, and B. said means for producing said second and third fields includes said first current conductor and a second current conductor disposed relative to said transmission path for producing a magnetic field longitudinal to the field of said first conductor and with the polarity thereof at said first locations being opposite to the polarity thereof at said second locations.

Claim 14

Magnetic logic apparatus as defined in claim 10 further comprising A. a first current source for applying current to said first current conductor to produce said first field, and B. a second current source for applying current to said second conductor with a selected one of two polarities.

Claim 15

Magnetic logic apparatus as defined in claim 1 further comprising control means for operating said field producing means to produce said fourth field throughout the production of said first field except for a selected offset time after initiation of said first field, said selected time being greater than the time required for a domain to expand, with said first field present, forward along said path from a location past the associated block site, and being less than the time required for a domain to expand, with said first field present, backward along said path from a location to the block site associated with the preceding location.

Claim 16

Magnetic logic apparatus as defined in claim 1 further comprising control means operating said field producing means to produce said fourth field throughout the production of said first field except for a selected time immediately preceding termination of said first field, said selected time being greater than the time required for a domain to expand, with said first field present, backward along said path from a location to the block site associated with the preceding location, and less than the time required for a domain to expand, with said first field present, forward along said path from a location to the next location.