Abstract: The data stored in a coincident block access bubble domain memory with bit-organized chips is encrypted by skewing or permuting selected word bits by predetermined amounts. This is implemented by providing an additional current loop on some or all of the chips which overlies the major loop pattern and has nodes at the similar vector poles of the major loop. The proper energization of selected ones of these additional current loops, under the control of a security key, inhibits or suppresses the advance of the bubble domains in the corresponding major loops for a predetermined number of cycles of the in-plane propagating field, thus skewing the word bits in these chips with respect to the remaining word bits in the unsuppressed chips. Decryption is accomplished by further inhibiting the same major loops for the necessary number of cycles to restore word bit synchronization throughout the memory.

Abstract: Gapless, single-sided propagation structures are provided for implementing the continuous movement of magnetic bubble domains in both straight lines and around reverse direction turns under the control of a reorienting in-plane field. One embodiment comprises a closed loop of open-sided, joined hexagonal patterns having traps and dead end legs at the joined corners to cause transfer from one hexagonal pattern to the next, thus implementing continuous circulation around the loop and preventing backtracking. Another embodiment employs straight, parallel strips joined at their ends to form a loop. Bubble movement is promoted by a series of angled strip legs intersecting the main strips to provide sequentially advancing magnetic poles as the field vector rotates.

Abstract: A three wire 3D core memory which utilizes the same balanced pairs of sense-inhibit conductors to conduct both high energy common mode inhibit currents and low energy differential mode core switching signals includes pairs of antiparallel Schottky diodes interconnecting the conductor pairs at symmetrical positions therealong intermediate the cores of each memory mat. As high energy common mode inhibit currents are generated small deviations from perfect symmetry of electrical characteristics along the sense-inhibit conductors results in the appearance of differential voltages which are substantial in comparison to switching signal voltages. The sense-inhibit recovery time required for dissipation of these spurious differential voltage signals before a memory read cycle can proceed consumes a substantial portion of a memory cycle for large stacks.

Abstract: An identity card contains a radioactive substance and information on the intensity of the radiation of said substance. When the card is used, for example in a banking transaction, the current intensity is measured and compared with the information on the intensity given on the card. If the current intensity and the given intensity agree, the card is to be considered genuine.

Abstract: An article identifying system especially adapted for use in identifying coded containers being transferred from one point to another by means which require that the containers be moved in a vertical direction while being moved in a horizontal direction.A code reading scanner mounted on a vertical carrier is positioned alongside the path of movement of the article. The carrier moves vertically in synchronism with the vertical motion of the container so that at whatever level the container passes the carrier position, the scanner will be at the same level as the container.To move the carrier vertically in synchronism with the vertical motion of the container, the motor driving the carrier is controlled by a signal generated by the vertical motion of the container.

Abstract: A differential detection device is provided for detecting the presence of magnetic bubbles in a data stream circulating on a magnetic wafer. The device utilizes an array of columns of permalloy elements to enlarge the magnetic bubbles being detected. A change in resistance of each of a pair of adjacent permalloy columns as a bubble traverses the detector is sensed and differentially detected to signify the presence of the bubble. In one embodiment of the invention, a second detector is used in conjunction with the first detector to provide operation in a mode in which bubbles in alternate positions in the data stream are directed into alternate channels including the first and second detectors respectively. After detection, the bubbles are redirected into a single data stream, while the output signals from the two detectors are merged to produce a data output signal reproducing the original data stream.

Abstract: A technique for enhancing readout of magnetic bubble data by producing two separate, complementary multiplicities of bubbles representing respectively the presences and the absences of bubbles in a data stream. A pair of detectors register the presence of the respective multiplicities of bubbles. The outputs of the detectors are compared to produce a single output indicative of the presence or absence of the original data bubble. In one embodiment a bubble logic gate causes a single bubble bit in the data stream to logically influence a train of bubbles in a separate closed circuit operating at a rate which is a multiple of the rate of the data stream. Depending on the presence or absence of a bubble in the data stream, the train of bubbles is directed to one or the other of a pair of magnetoresistive elements spanning the length of the train of bubbles. The magnetoresistive elements form part of a balanced bridge circuit.

Abstract: A credit card reader is described which includes two magnetic readout heads whose gaps are spaced from each other a distance equal to one half the distance between adjacent, uniformly spaced bits of binary coded information. The coded data is recorded on a linear length of the credit card. The two similar sets of signals are extracted, one delayed relative to the other, as the heads scan the data. Decoding circuitry is described which provides information corresponding to the recorded data independently of the relative speed at which the credit card is moved or is swept past the readout heads.

Abstract: A word arrangement matrix memory of high bit density having a flux keeper is known in which a number of word lines provided on a flux keeper plate are mounted on the surface of a substrate on which a number of digit lines of magnetic strips each comprising a conductive strip coated with at least one ferromagnetic thin film is provided.In accordance with this invention, the digit lines comprises a plurality of straight sections disposed in parallel at regular spaces, corresponding digit lines of the respective sections being interconnected to one another in series or in parallel. The flux keeper plate has, on the surface facing the said surface of the substrate, a number of parallel column grooves facing the sections of the digit lines and a number of parallel row grooves intersecting at right angles with the column grooves.

Abstract: A magnetic device comprising a first and a second plate of a magnetic material between which domains are situated. An interaction force occurs between the domains in the two plates. Stable domain positions in a second plate define equally stable domain positions in a first plate. One or both plates can be provided with domain guiding structures. Domain displacement in one plate can control a domain displacement in the other so that a variation in the interaction force is produced.

Abstract: The insertion of new data into a major-minor loop memory is effected by selectively controlling the passage of bubbles through at least two gates provided between a bubble generator and the major loop. In a two-dimensional array of such memories, the write process is initiated by first applying a transfer signal to a selected row of the memories to transfer the data in the row into their respective major loops for subsequent erasure. Then, a gate signal is applied to a first gate of each memory in the selected row to condition it for write. Another gate signal is applied to a second gate of each memory in a selected column in accordance with the data to be inserted. This arrangement permits new data to be inserted into only the memory of the array that is located at the intersection of the selected row and column.

Abstract: A bubble domain driving apparatus is provided in which a large memory device with a storage capacity of 256 megabits, for example, is divided into 64 smaller memory elements, each thereof comprising one or plurality of thin magnetic film strips for bubble domain, and each of the 4-megabit smaller memory elements is provided with its own coils for applying in the plane thereof bubble domain driving rotating fields with the coils adapted to be selectively energized.

Abstract: An ejecting device for a tape record cartridge capable of being incorporated in a combination set of radio comprising a push-button and a record player, comprises a detent roller device for detaining the tape cartridge, a solenoid device which actuates the detent roller device, and a switching device linked with the push-button system of the radio set.

Abstract: A method of producing a high resolution information storage disc includes the steps of forming a grooved disc coated with an electron beam sensitive material, exposing the coated disc to a signal modulated electron beam, replicating the exposed disc to form a second disc of opposite contour, and utilizing the second disc to produce discs having positive-shaped groove and signal information.

Abstract: An electrostatic transducer comprising a vibrating plate or electret diaphragm which has a monocharge on its surface and including a pair of back electrodes clamping the electret therebetween and including an electrically conductive electrostatic shield covering the back electrodes so as to increase the fidelity and life of the transducer.

Abstract: Three magnetic bubble logic gates are disclosed in this application. One gate produces the AND and NAND logic functions, one gate produces the OR and NOR logic functions, and the third gate produces the majority function. In the gate providing the AND and NAND functions and in the gate providing the OR and NOR functions, a bubble generator applies magnetic bubbles at the binary variable rate to a first bubble propagation track, which diverges into two downstream tracks with the bubble being transmitted through the point of divergence to a preferred one of the two downstream tracks unless repelled to the unpreferred downstream track. Bubbles representing the binary variables are applied to data propagation tracks which approach the point of divergence in the first track. In the gate providing the AND and NAND functions, this approach is only close enough so that simultaneous bubbles representing both binary variables are required to repel a bubble at the point of divergence to the unpreferred track.

Abstract: Parallel "crow-foot" circuit elements in different bubble paths symmetrical about an axis parallel to and between the paths propagate bubbles in opposite directions with the same set of pulsed drive fields and are used to build closed loop paths with parallel sides. Special cornering elements couple parallel channels to form rectangular loops.

Abstract: Magnetic device comprising at least one thin layer of a magnetisable material which has a preferred direction of magnetisation substantially at right angles to the surface of the layer. Magnetic domains are produced by a magnetic field which is situated substantially in the plane of the layer and does not change direction and enables similar domains to be produced. The domains are there after maintained by a field normal to the layer. A domain guide structure may also be provided on the layer to move the domains.

Abstract: A method and apparatus for distributing and controlling inventories of food items and the like in which a plurality of individual elements are coded to identify both a corresponding inventory item and a magnitude such as a price associated with that inventory item. A holder member for collecting together a selected group of the individual elements to enable identification of the corresponding food items ordered by a customer as well as sensing the total price thereof. Coding each element so that one dimension thereof extends in a predetermined direction a distance proportional to the price of the corresponding food item.

Abstract: A telephone answering apparatus has a forward drive time delay relay which causes a tape bearing a series of messages to advance for approximately 30 seconds subsequent to the reproduction of the last message in the series. The forward drive time delay relay cooperates with a recording amplifier so as to prevent recording of information on the advanced portion of the tape. The relay also cooperates with an erase circuit to cause recorded information on the advanced portion of tape to be erased to thereby create a no-signal or silent portions of tape. The advanced portions of the tape are detectable by a no-signal detector during rewind of the tape which automatically stops rewind when a no-signal portion is detected. A method is disclosed for generating silent portions on a tape and for automatically stopping rewind in a telephone answering apparatus at points, prior to complete rewind, where the no-signal portions are detected.