Abstract: A matrix type magnetic recording/reading head made in integrated fashion, including an electrically non-conductive ceramic substrate having a first main face and a second main face, each provided with connection areas. The two areas of the two faces are interconnected in sets of two by internal connection elements. A layer with high magnetic permeability is deposited on the first face of the substrate. The substrate bears a first series of row conductors and a second series of column conductors intersecting the row conductors, each conductor being connected to a connection area of the first face. Pairs of magnetic poles are located substantially at the intersection of the row conductor and column conductors, the poles of each pair separated by a gap space and being magnetically coupled to the layer with high magnetic permeability in two opposite zones defined by the intersection of a row conductor and a column conductor.

Abstract: Disclosed is a system for the recording of data on optic disks. Presently used optic disks, which can be read with lasers working in wavelengths of the visible region (between 0.5 and 0.8 microns), have a maximum surface storage density of the order of one data bit per elementary zone having an area of about one square micrometer. Beyond this limit, the diffraction does not allow the neighboring zones to be distinguished. A means is proposed to considerably increase the storage capacities: in an elementary zone of a layer, an information bit is written not in the form of a point of absorption of a laser light but in the form of a diffraction grating with a determined pitch. Several diffraction gratings, having pitches different from one another, may be superimposed at the same position, enabling the recording, in one and the same zone, of several information bits. The diffraction gratings are made by a periodic local variation of the optic index of the layer.

Abstract: The disclosure relates to a magneto-optical reading head. A magneto-optical head comprises an optically active part which is a very thin magnetic layer that causes the rotation of the plane of polarization of the light as a function of its magnetic polarization which is itself linked to the magnetic polarization of the magnetic tape that bears the information elements to be read and moves past the thin layer. Instead of using a focusing optical device to illuminate the optically active part, it is provided that the head will comprise an optical guide which ends directly before the active part and is such that the plane of incidence of the light rays on the optically active part is perpendicular to the general direction of elongation of a gap region before which the magnetic tape passes.

Abstract: A memory display system is provided including:a recording support medium having a layer of a luminescent material capable of storing energy coming from a light beam, electrodes enclosing the luminescent material and applying thereto an electric field for releasing the previously stored energy in the form of a beam;an optical transmission device placed in the path of said beam;a sensor receiving this beam and converting the intensity of the light beam into an electric signal;a processing circuit receiving said electric signal, processing it and controlling display thereof on a display device.