Abstract: A holographic system for storing data on an interference pattern in a hologram storage medium includes a light source for emitting a laser beam, a beam splitter, modulating means and a refractive material. The beam splitter divides the laser beam into a reference beam and a signal beam and the modulating means modulates the signal beam to generate a modulated signal beam. The refractive material refracts the reference beam to generate a refracted reference beam, wherein the refracted reference beam interferes with the modulated signal beam in the hologram storage medium to generate the interference pattern.

Abstract: A magnetic memory has a substrate, a magnetic film provided on the substrate including a recording medium capable of producing a recording carrier, and a light waveguide layer on the magnetic film or on that surface of the substrate which is opposite to a surface on which the magnetic film is present. Recording and reproduction of information are effected relative to the magnetic film by a light propagated through the light waveguide layer.

Abstract: In a magnetic bubble generator having an ion-implanted track (1), a conductor pattern is composed of hairpin conductor patterns (5, 6) of two layers with an insulating layer (12) interlaid, and a part of intersection of the fore end parts of the gaps of these hairpin conductor patterns (5,6) is positioned in the vicinity of a cusp (4) of the ion-implanted track (1). The hairpin conductors may be electrically connected to each other and may be supplied by a common source. Thereby an error to be caused by a generated bubble stretching so much as to be divided into a plurality of pieces can be prevented, and the bubble can be generated by a small current pulse, while the amplitude margin thereof is enlarged.

Abstract: The bubble memory comprises a magnetic layer in which the magnetic bubble can move under the action of a rotary field, a deposited pattern formed from a high permeability magnetic material and separated from the magnetic layer by an electrical insulating layer, a U-shaped electric conductor placed between the magnetic layer and the deposited pattern and electrically insulated therefrom, the deposited pattern covering the base of the internal space defined by the electric conductor and thus defining a nucleation position. The generator also comprises an implanted pattern produced in a fraction of the thickness of the magnetic layer, the implanted pattern at least covering the nucleation position.

Abstract: A bubble generator for use in a bubble memory device combines a nucleating generator and replicating generator in a unified structure with first and second hairpins disposed at respective first and second regions to define nucleation and replication sites. The conductor layer is configured such that the same polarity of current flow causes magnetic fields of opposite sense at the nucleation and replication sites. The nucleation site is used only to generate the seed bubble required at the replication site. Once the seed bubble is present, the replication site is utilized to produce the data stream. The nucleation and replication sites are preferably spaced apart with a propagation track extending from the former to the latter, and the first and second hairpins are series-connected with the series connection crossing the propagation path. The hairpins are preferably directed oppositely so that when the rotating field is in the right phase for replication, it is 180.degree. out of phase for nucleation.

Abstract: A propagation delay generator is provided for controlling the duration of a bubble generate waveform of a bubble memory system. A first means is responsive to a digital input signal and provides an initializing signal to a current source. A capacitor is charged, responsive to an R-C time constant, by an increased voltage level prompted by the initializing signal. A second means is responsive to the charging signal in excess of that required to charge the capacitor. The second means thereby provides a digital output that is delayed from the digital input signal.

Abstract: A magnetic domain device has at least one post element formed from a material that exhibits magnetic domain characteristics and that is positioned on a nonmagnetic substrate material. A pair of electrical drive lines associated with a post element permit coincident current selection of the post element to nucleate a magnetic domain reversal, and an additional current introduced into an adjacent drive line establishes an additive magnetic field to assist the propagation of a domain wall associated with the nucleated magnetic domain reversal so that the direction of magnetization of the post element is reversed.

Abstract: A magnetic bubble store, using adjoining non-implanted motifs as bubble-propagating motifs, the store comprising 3n identical, electrically interconnected storage devices, n being a positive integer, which are produced on an identical circuit chip and each comprise minor loops for storing the bubbles, at least one major loop acting as an access loop for the minor loops, first electrical component enabling bubbles to be transferred from the minor loops to the major loop and vice versa, a second electrical component enabling bubbles to be produced on the major loop, and a third electrical component enabling the bubbles on the major loop to be detected, the third, identical component, each formed by an electric conductor for bubble extension and contraction and a magneto-resistive element, being disposed in directions making an angle of 120.degree. with one another.

Abstract: A current ramp generator is provided for controlling the fall time of a bubble generate waveform of a bubble memory system. Gate circuitry is responsive to a digital input signal and provides an initializing signal to a current source. The current source charges a capacitor and thereby provides an increasing signal to a current mirror whose output sinks current from a control amplifier of the bubble memory system.

Abstract: A magnetic bubble domain device nucleation source for producing magnetic bubble domains is disclosed, in which bubble domains along with possibly unwanted duplicate bubble domains are produced in response to a current pulse. A first bubble domain guide structure is provided which coupled and disposed directly adjacent the nucleator and defines a first bubble domain propagation path for guiding the movement of generated bubble domains in response to a cyclical change in orientation of a reorientating field within the plane of the magnetic layer. This first guide structure functions to receive bubble domains representative of information. More particularly, a second bubble domain guide structure is provided also disposed directly adjacent the nucleator and the first bubble domain guide structure.

Abstract: The magnetic bubble memory device of this invention is arranged such that a magnetic bubble detector and a nucleation type magnetic bubble generator in a chip are made to operate at different phases of the same operation cycle of a rotating magnetic field. Therefore, the operation time of the magnetic bubble detector and the operation time of the nucleation type magnetic bubble detector are completely separated from each other, although they are involved by the same cycle of operation of the rotating magnetic field. Consequently, the magnetic bubble detector can perform the detecting operation, without being affected by large amounts of noise which are generated during the operation of the nucleation type magnetic bubble generator.

Abstract: A bubble (domain) generator comprising a pair of relatively long elements of suitable magnetic material, such as permalloy, separated by a narrow gap, near which bubbles will be generated in the bubble film by the combined effect of local in-plane and perpendicular magnetic field components to assist in nucleation. In one embodiment, the gap is formed straight by spaced apart edges between the elements and, in another embodiment, the gap is formed to define an apex by V-shaped by complementary tapered spaced apart edges between the elements. Both embodiments may have their gap edges brought close to the bubble film and may have a current carrying hairpin loop conductor substantially surrounding the gap to assist in nucleation.

Abstract: Magnetic bubble domain memory circuit in which magnetizable overlay patterns of magnetically soft material, e.g. permalloy, are provided as bubble propagation elements on a bubble-supporting magnetic layer to define major and minor bubble propagation paths. The bubble propagation elements are arranged to form major propagation paths defining a bubble input section and a bubble output section respectively. A plurality of minor propagation paths in the form of closed storage loops defining a bubble storage section are disposed between the input and output bubble sections, being arranged in even and odd blocks of minor propagation paths. Input swap transfer gates and output replicate gates are provided between the bubble storage loops and the input and output sections respectively. The input swap transfer gates and the output replicate gates are of double level construction, each type of gate including a hairpin element at the first level and a 90.degree.

Abstract: An improved magnetic bubble domain nucleator is provided which uses a magnetic wall, such as a charged wall, Neel wall, or Bloch wall, to assist nucleation. In a preferred embodiment, a magnetic charged wall is produced in an ion implanted region of a magnetic material with an in-plane magnetic field, and an applied nucleating magnetic field is produced by current in a conductor. The combination of the first magnetic field associated with the charged wall and the second magnetic field produced by current through the conductor is sufficient to nucleate a bubble domain in the magnetic medium whereas each of these fields acting alone is not sufficient for nucleation. Since the first magnetic field provides a component of the total nucleating field, the amount of nucleation current required in the conductor is reduced.

Abstract: A magnetic bubble information writing device capable of carrying out writing without erasing old information representing either "0" or "1" at a location, where new information is to be written, by means of only a single hairpin-like conductor loop is disclosed, in which the single hairpin-like conductor loop is disposed at a projecting portion of permalloy patterns, enclosing the portion.

Abstract: A magnetic bubble information writing device in which a conductor loop is disposed on the magnetic bubble propagation circuit and in which magnetic bubbles are generated by sending pulse current through the conductor loop, the device having a means which after having sent the bubble generating pulse current through the conductor loop, sends pulse current for annihilating stray bubbles through the same, the stray bubble annihilating pulse current having a polarity opposite to that of the bubble generating pulse current.

Abstract: A cylindrical magnetic domain element is disclosed which utilizes a cylindrical magnetic domain (a magnetic bubble) produced by the application of a bias magnetic field to a magnetic sheet of orthoferrite, garnet or the like. Propagation patterns for the cylindrical magnetic domain are composed of a plurality of sets formed on one side of the magnetic sheet and have a multilayer construction with a non-magnetic film of SiO.sub.2 or the like between the layers. This multilayer construction allows for the formation of a propagation pattern having a relatively narrow pattern gap. Further, the propagation pattern is disclosed as having uniaxial magnetic anisotropy, which facilitates the magnetic bubble propagation and ensures retaining of the magnetic bubble.

Abstract: Magnetic bubble domain generator and annihilator for use in a magnetic bubble domain memory device of the major-minor bubble propagation path type. The magnetic bubble domain generator and annihilator structure employs a thin metallic loop which is disposed adjacent to a bubble propagation path and is alternatively operable in both a bubble generation and bubble annihilation mode. A DC bias field is provided to the magnetic bubble domain memory circuit device and exists within the metallic loop of the bubble generator and annihilator structure. Upon applying a current pulse to the thin metallic loop from a pulse generator, the bubble generator and annihilator structure is caused to operate in one of the two possible modes. When the current pulse reduces the DC bias field below a predetermined value, the metallic loop operates as a generator to generate a magnetic bubble.

Abstract: A block oriented random access memory (BORAM) magnetic bubble domain system which provides increased throughput of information and reduced access or read time for the same information as compared to existing major-minor or decoder accessed chip organizations which it is designed to replace.

Abstract: A field-access, magnetic bubble memory organized in a major-minor configuration includes an extra set of minor loops dedicated to fault correction. The loops of the extra set are coupled to a major path in a manner to move the information in the loops of the set controllably out of synchronism with respect to the information in the remaining loops. Thus, information in the loops of the extra set can be inserted into the data stream originating from the remaining loops at positions of missing data from faulty ones of those loops.