Mutually exclusive parallel-sided loops

A field-accessed bubble propagation system, comprising a sheet of magnetic bubble material, means for producing and maintaining bubbles therein, a ferromagnetic over-lay pattern operatively disposed on said sheet including first and second parallel bubble paths composed respectively of different discrete mutually exclusive circuit elements, said respective mutually exclusive circuit elements belonging to the same subset of first set of field accessed elements composed of at least two subsets S.sub.i and S.sub.j, each composed of elements designed with respect to elements in the other subset such that the respective members of S.sub.i and S.sub.j are distinguished collectively from each other only by the fact that there exists an in-plane dirve field system F.sub.i which propagates bubbles on each species of elements in S.sub.i without causing bubble propagation on any element in S.sub.j and there exists another in-plane drive field system F.sub.j which propagates bubbles on each species of element in S.sub.j without causing bubble propagation on any element in S.sub.i, the shape and orientation of said elements of said second path being symmetrical to the shape and orientation of said elements in said first path with respect to a symmetry line between and parallel to said first and second paths, said overlay pattern further including a third bubble path including a discrete mutually exclusive circuit element belonging to a subset of a second set arranged to transfer bubbles on said first path to said second path, and means for applying a magnetic drive field associated with said same subset of said first set and said subset of said second set in the plane of said sheet to propagate bubbles simultaneously in opposite directions along said first and second paths and also therebetween on said third path, said drive field applying means including means for generating a set of sequential discrete field orientations to which said first, second and third paths are simultaneously responsive to propagate bubbles.

A field-accessed bubble propagation circuit comprising a sheet of magnetic bubble material, means for producing and maintaining bubbles therein, a ferromagnetic overlay pattern operatively disposed on said sheet including a closed loop bubble path composed of discrete mutually exclusive circuit elements, said mutually exclusive circuit elements belonging to the same subset of a set of field accessed elements composed of at least two subsets S.sub.i and S.sub.j, each composed of elements designed with respect to elements in the other subset such that the respective members of S.sub.i and S.sub.j are distinguished collectively from each other only by the fact that there exists an in-plane drive field system F.sub.i which propagates bubbles on each species of elements in S.sub.i without causing bubble propagation on any element in S.sub.j and there exists another in-plane drive field system F.sub.j which propagates bubbles on each species of element in S.sub.j without causing bubble propagation on any element in S.sub.i, said path having two parallel sides which propagate bubbles in opposite directions on respective circuit elements which are different but belong to said same subset, and means for applying a magnetic drive field associated with said same subset in the plane of said sheet to circulate bubbles in said closed loop, said means for applying a magnetic drive field including means for applying a sequence of discrete pulsed drive field orientations to which the circuit elements in said parallel sides are simultaneously responsive to propagate bubbles around said closed loop.

A field-accessed bubble propagation system, comprising a sheet of magnetic bubble material, means for producing and maintaining bubbles therein, a ferromagnetic overlay pattern operatively disposed on said sheet including a first bubble path composed of discrete, mutually exclusive circuit elements, said mutually exclusive circuit elements belonging to a subset of a set of field accessed elements composed of at least two subsets S.sub.i and S.sub.j, each composed of elements designed with respect to elements in the other subset such that the respective members of S.sub.i and S.sub.j are distinguished collectively from each other only by the fact that there exists an in-plane drive field system F.sub.i which propagates bubbles on each species of elements in S.sub.i without causing bubble propagation on any element in S.sub.j and there exists another in-plane drive field system F.sub.j which propagates bubbles on each species of element in S.sub.j without causing bubble propagation on any element in S.sub.i, and a second bubble path parallel to said first path composed of discrete mutually exclusive circuit elements different from those of said first path but belonging to the same subset as those of said first path, whose shape and orientation are symmetrical to the elements in said first with respect to a symmetry line between and parallel to said first and second paths, and for means applying a magnetic drive field associated with said same subset in the plane of said sheet to propagate bubbles simultaneously in opposite directions along said first and second paths, said means for applying a magnetic drive field including means for applying a predetermined set of sequential pulsed discrete drive field orientations to which the elements in said first and second paths are simultaneously responsive to propagate bubbles.