Abstract: A method for the making of a magnetic recording/reading head comprises the following steps:the making of magnetic excitation wires on or in a first face of a substrate having this first face and a second face opposite the first face;the making, on the first or second face of the substrate, of at least two magnetic poles separated by a gap;the drilling of holes through the substrate from the face opposite the one bearing the magnetic poles, each ending in such a way that there is magnetic coupling between the bottom of the hole and the pole;the deposition of a layer of material with high magnetic permeability in the holes and in the zones of the substrate located between the holes. Applications: the making of magnetic recording/reading heads for video-tape recorders, computer peripherals and professional recording machines.

Abstract: Magnetic write/read heads for writing/reading information on a recording medium passing in front of the heads include several groups of magnetic write/read heads, each group of magnetic write/read heads including several pairs of poles. Each pair of poles is separated by a head gap of an integer multiple of an elementary track width b and forms several head gaps E0 to E7. The head gaps (for example El) have a first width such that they can write across a first width of the recording medium, and the second head gaps (for example E2) have a second width less than the first width and are arranged in such a way that the second head gaps write/read an area of the recording medium superimposed on the area of the recording medium write/read by the first head gaps. The magnetic write/read heads are suitable for applications where multitrack write/read heads are required.

Abstract: The invention concerns a magneto-resistive magnetic sensor comprising a magneto-resistive element, the resistance of which varies as a function of the applied magnetic field and two pole pieces that collect the magnetic field to be detected so as to concentrate it in the magneto-resistive element, each pole piece being positioned to partially overlap the magneto-resistive element, a current I passing through this magneto-resistive element, wherein the zones of the magneto-resistive element that are overlapped by pole pieces are cut out such that the current that passes through the magneto-resistive element is located in a zone in the air gap between the two pole pieces.

Abstract: The read head according to the invention comprises a matrix network of elementary heads whose magnetic circuit comprises a magneto-resistive element. The different elements are electrically connected in columns and traversed by a current. Head selection lines enable the active line of heads to be selected. The read signal is collected on each column.

Abstract: The invention relates to a process for producing a plurality of magnetoresistive sensors on the same substrate. The invention particularly has as its object to facilitate a polishing phase of this process. The process of the invention comprises depositing a layer of a magnetoresistive material on a substrate, and then forming in this layer a plurality of magnetoresistive elements. The process further comprises making, at the site of each sensor and before the depositing the magnetoresistive layer, an inclined surface, in such a way that each magnetoresistive element is formed on this inclined surface and exhibits an edge directed outward from the substrate.

Abstract: A magnetic reading device, of the type comprising multiple magnetic read heads, incorporates read heads each formed by a magneto-resistance element having a resistance which varies as a function of an outside magnetic field. The magnetic reading device comprises a network of line conductors intersected with a network of column conductors to form intersections at which a read head is provided. The first and second ends of each magneto-resistance element forming the read heads are respectively connected to a line conductor and to a column conductor of the corresponding intersection, and a control voltage is applied to the line and column conductors by a switching element for each line conductor, column conductors being connected to a current sensor. A simplification of the control of read heads results from this arrangement, while avoiding the effect of the heads not selected on the variations of current coming from the selected heads.

Abstract: Magnetic read heads with magneto-resistance effect of the multilayer type, are provided in a new arrangement making it possible in particular to facilitate a collective arrangement of these heads. Each read head comprises a magneto-resistance element formed by a sensitive magnetic layer superposed on a stable magnetic layer. Each read head comprises a magnetic circuit in a ring opened by an air gap, the sensitive magnetic layer being inserted in the magnetic circuit in a ring, the stable magnetic layer being outside the ring of the magnetic circuit. The arrangement of the magnetic read heads is particularly adapted for reading high density magnetic storage media.

Abstract: Disclosed is a magnetic head comprising chiefly two thin or thick layers of magnetic materials located in a same plane and separated by a gap layer of non-magnetic material, also made in the form of a thin or thick layer. This gap layer forms a determined angle with the plane of the layers of magnetic materials. Methods are also provided for the making of such a head. In particular, these methods make it possible to determine, with precision, the angle of the gap with the plane of the layers of magnetic materials. Applications: magnetic write/read heads for computer peripherals (using tapes or disks), and possibly video tape recorders.

Abstract: A magnetic head and a method for producing the magnetic head comprising the steps of:producing a groove in a first face of a substrate;depositing a material having good magnetic characteristics on the walls of the groove;depositing a non-magnetic material in the groove over the material having good magnetic characteristics;machining a second face of the substrate until the non-magnetic material is reached, so as to create a magnetic gap; andbonding a part carrying a magnetic layer onto the first face of the substrate so as to form a magnetic circuit.

Abstract: A method of making a multitrack head consisting in making a first network of grooves in a block of ferrite, filling the grooves with glass, planing down the surface, making a second network of grooves in a second block of ferrite, bonding these two blocks, trueing the base of the first block, depositing poles and making the winding wires go through.

Abstract: A method of simultaneous manufacture of a plurality of planar magnetic heads on a wafer or a slab made of non-magnetic material designed to be cut out to separate each head. The method can be applied to magnetic heads of the type including a micro-gap formed between two magnetic poles, facing a gap defined between two wire-wound ferrite cores. The method consists in depositing said thin layer magnetic poles on a first face of a wafer made of non-magnetic material and in hollowing out, in the face opposite to said wafer, at least one cavity for housing said wire-wound cores so as to obtain a calibrated spacing or a junction between the upper part of each of said wire-wound cores and said thin layer magnetic poles.

Abstract: A process of manufacturing an apparatus incorporating a layered thin film structure, wherein said process more particularly obviates the need to repeat on a first part of the apparatus the effects of certain operations required to produce the second part formed by the layered thin film structure. For this purpose, the process consists of utilizing a substrate to produce an intermediate assembly (12) comprising the thin film structure (11), then attaching the intermediate assembly (12) to the first part (10), then at least partially eliminating the intermediate substrate (13).

Abstract: A method for achieving the planar surface of an active face for magnetic recording/reading heads. The planar surface of the active face is obtained by grinding, the active face being of the type where, before the grinding operation, the level of the material forming the gap is recessed with respect to the magnetic poles, the method comprising depositing over the recess a thin layer of non-magnetic material with a thickness at least equal to the recess of the gap. The non-magnetive thin layer may then be ground to obtain the planar surface of the active face.

Abstract: A method for fabricating magnetic recording/reading heads. A substrate made of magnetic material is provided with a groove of a predetermined width. The surface of the substrate bearing the groove becomes the active face for the magnetic head. The face of the substrate having the groove is ground, and then filled with a non-magnetic material to form a gap. The filling causes the non-magnetic material to jut out of the groove. The material which juts out is ground off until the level of the substance is reached.