Abstract: A data storage device for storing digital information in a readable form is described made up of one or more memory elements, each memory element comprising a planar magnetic conduit capable of sustaining and propagating a magnetic domain wall formed into a continuous propagation track. Each continuous track is provided with at least one and preferably a large number of inversion nodes whereat the magnetization direction of a domain wall propagating along the conduit under action of a suitable applied field, such as a rotating magnetic field, is changed.

Abstract: A method and apparatus for conditioning a magnetic read/write head to substantially eliminate read-back pulse distortions associated with unfavorable magnetic domain patterns in the head stores the polarity of the last write current pulse of a write pulse train applied to the head-coils. This polarity is compared to a pre-determined reset current pulse polarity. If the last write current polarity is opposite to the reset current polarity, then a reset pulse, or a series of pulses, having the pre-determined reset polarity is applied to the head prior to performing a read operation with the head. The pre-determined reset polarity corresponds to the polarity that resets the head to the magnetic domain state most preferred for reading due to reduction of read-back distortion. The reset pulse, or pulse train, according to the present invention is of constant polarity. If the last write current pulse polarity is the same as the reset polarity, then no reset pulse is applied to the head.

Abstract: A three-dimensional magnetic memory medium which comprises a substrate, a plurality of magnetic layers and a plurality of nonmagnetic layers. The magnetic layers and the nonmagnetic layers are alternately stacked one above the other on the substrate. Each magnetic layer comprises a transfer area, wherein assuming that n is a positive even whole number, the (n-1)th magnetic layer (the 3rd layer, the 5th layer, the 7th layer, . . .) has a transfer pattern different from that of the nth magnetic layer (the 2nd layer, the 4th layer, the 6th layer, . . .). An uppermost magnetic layer is used as a signal writing area and as a signal reading area. A position corresponding to a signal "1" and a position corresponding to a signal "0" are arranged in the signal writing area at a position superposed on a position of "1" and on a position of "0" in a transfer pattern of the (n-1)th magnetic layer, respectively.

Abstract: A method of transferring Bloch lines present in a domain wall of a magnetic domain formed in a thin magnetic firm, includes cyclically forming asymmetrical potential wells along the domain wall in order to locate the Bloch lines at predetermined positions of the domain wall, and applying a pulsed magnetic film to shift the Bloch lines from a predetermined potential well to another potential well. In a magnetic memory for recording information using Bloch lines as an information carrier, a memory substrate has a stripe magnetic domain defined by a domain wall along which asymmetrical potential wells are cyclically formed to stabilize the Bloch lines along the domain wall. The Bloch lines are written in the domain wall in accordance with input information, the Bloch lines so formed are read out, and the read-out Bloch lines are converted into an electrical signal.

Abstract: An improved magnetic bubble memory device includes a continuous propagator overlay on a sheet of magnetic material. The propagator overlay being adapted to reduce the statistical switching effects and overall coercivity of the propagator overlay. The propagator overlay consists of multiple layers of soft magnetic material being alternately arranged with non-magnetic material, in a geometric pattern specified so as to produce domain walls only internal to the pattern boundary, the soft magnetic material being chosen for its initial low coercivity characteristics and having characteristics approaching zero magneto-striction.

Abstract: A magnetic bubble device includes ion-implanted bubble propagation tracks of meandering cord-like configuration to assure improved bubble propagation characteristic. Amplitude of a region in which inplane magnetization layer is absent or alternatively thickness thereof is smaller than that of other region, as measured in the direction perpendicular to the bubble propagating direction, is not greater than 7/8 of a pitch of the meandering pattern in the bubble propagating direction. The amplitude is more preferably selected so as to meet the condition that 1/4.ltoreq.W/P.ltoreq.3/4 for assuring much stabilized bubble propagating operation.

Abstract: The invention is directed to continuous (gapless) propagation structures for use with magnetic bubble domain devices. The gapless structures are arranged so that magnetic bubbles will propagate therealong without a significant change in size or diameter of the bubble. In addition, the structures are configured so that the bubbles will propagate in a preferred direction without ambiguity.

Abstract: A method of and an apparatus for magneto-resistively detecting information in a cross-tie memory system is disclosed. The detector includes a first conductive element, which is the terminating portion of an electrically-conducting wide-narrow edged propagating drive line, and second and third conductive elements that are serially aligned along a magnetic, serrated-edged data track, which three conductive elements form two gaps therebetween. The two gaps are oriented along the data track at respective narrow portions, a first narrow portion which may support a cross-tie but which second narrow portion will not support a cross-tie. A differential sense amplifier is coupled across the two gaps using the second narrow portion as a reference segment to differentially detect the presence vel non of a cross-tie in the first narrow portion.