Reverse-rotation transfer gates
AssigneeBell Telephone Laboratories, Incorporated
InventorsDirk J. Muehlner, Terence J. Nelson, Raymond Wolfe
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Abstract
Transfer between paths in ion-implanted magnetic bubble memories has been achieved without the use of transfer conductors. The transfer mechanism takes advantage of the three-fold anisotropy of the implanted drive layer which makes it possible for bubbles to pass freely through gaps in one direction while being obstructed from passing through in the other direction. Transfer is controlled by a brief reversal of the direction of rotation of the in-plane field. In one embodiment, a bidirectional transfer gate is employed. Configurations using unidirectional gates and hybrid gates using conductor and reverse-rotation controlled transfer are also shown.
Claims10
A magnetic bubble memory comprising a layer in which bubbles can be moved, said layer having a threefold axis of symmetry defining a preferred magnetization direction in the plane of said layer, means for providing a magnetic field reorienting cyclically in the plane of bubble movement, means for changing the direction of said in-plane field selectively, a pattern of ion-implanted regions in said layer defining at least first and second paths along which bubbles can be moved in response to said in-plane field, said pattern also defining means for transferring a bubble from said first to said second path in response to a temporary change in the direction of said in-plane field.
A magnetic bubble memory comprising a layer in which bubbles can be moved, said layer having a threefold axis of symmetry defining a preferred magnetization direction in the plane of said layer, drive means for providing a magnetic field reorienting cyclically in the plane of bubble movement, a pattern of ion-implanted regions in said layer for defining at least first and second paths and a gap therebetween, said gap having an axis aligned with said preferred magnetization direction in a manner to permit a bubble in said paths to pass freely therethrough in a first direction but not in a second direction, said in-plane field being operative normally to move bubbles in said first direction through said gap, said memory being characterized by means cooperative with said drive means for altering said drive field in a manner to move a bubble in a second direction into said gap for transferring said bubble from said first to said second path.
Dependencies are inferred from the claim text.