Abstract: A radiation interruption keyboard is provided including a key matrix, a series of light emitting diodes and a series of photodiodes. With each diode is associated a column along which the light radiation propagates in a hollow channel. With each photodiode is associated a line along which the light radiation propagates in a strip made from a transparent material. Each strip has a deflecting area for deflecting the radiation from the light emitting diodes towards the corresponding photodiode. Upstream of each deflection area, in the path of the light beam, and in direct view of the corresponding light emitting diode is a flap for interrupting the radiation controlled by a key. The light emitting diodes are controlled sequentially and cyclically.

Abstract: The register comprises a soft magnetic layer in which is formed the domain propagation channel, a hard magnetic layer and a domain shift conductor. The propagation channel comprises a writing box, a reading box, narrow domain storage zones, widened domain growth boxes, a domain increasing zone, upstream the reading box, which includes intermediate domain increasing boxes, which have a large surface with respect to that of the other growth boxes. Each increasing box comprises lateral shoulders and is not covered by the shift conductor. A coil or a solenoid creates at the level of the increasing zone and of the reading box, a pulsating external magnetic field.

Abstract: Magnetic memory element for transport ticket or credit card, comprising a support and at least one ferromagnetic layer containing at least one piece of information recorded therein and a layer of a non-magnetic diffuser in contact with the ferromagnetic layer to irreversibly destroy the magnetism of the ferromagnetic layer when the element is heated.

Abstract: A magnetic domain propagation register carrying out the propagation of the domains under the effect of electric currents, comprising an insulating substrate, a soft magnetic layer on the insulating substrate, in which is formed a propagation channel, a hard magnetic layer on the soft magnetic layer, except in areas defining the propagation channel, an insulating layer on the soft and hard magnetic layers, and a conduction layer in a Greek border pattern on the insulating layer, constituted by parallel segments perpendicular to the propagation channel, the propagation channel comprising widened boxes at the intersection of the propagation channel with the segments of the conduction layer.

Abstract: The invention comes within the field of digital memories having thin magnetic layers, for the propagation of domains. This memory is constituted by an anisotropic linear magnetic channel which is applied on a glass substrate and which has a single shift conductor in a Greek border configuration superimposed on it. Areas made of soft magnetic material are provided at the intersection between the channels and the conductors. According to such a structure, high-capacity shift registers which are of relatively rapid access (one shift step lasts about 500 nanoseconds) can be produced.

Abstract: In digital registers for the propagation of magnetic domains in thin layers, one of the shift conductors is combined with an extra layer which is magnetically hard and which sets up a permanent field on the edge of that conductor, this facilitating the propagation of the domains.

Abstract: Reading unit for a shift register according to the thin magnetic layer technology. For reading, the magnetoresistance effect is used. According to the invention, an electrical conductor, which overhangs the propagation channel is interrupted at the central point of the reading unit and a hard magnetic layer whose magnetization is directed perpendicularly to the easy axis of the propagation channel is deposited at that point. That layer tends to align the magnetization of the channel with its own magnetization and makes it possible, in co-operation with an energizing conductor, to obtain a difference in the resistance of the reading unit between the two states of a digital data item.