Abstract: A magneto-optic multitrack reading head which features a structure with plane layers deposited in a course of a same deposition procedure. These layers include a magnetic layer exhibiting a Kerr effect, an inter-iron gap layer and a magnetic layer for magnetic circuit closing. The magnetic layers define adjacent elementary heads, so as to be able to read multitrack media.

Abstract: A shift register having several cascaded stages, each stage containing an output at a first node connected to a next stage, a first input connected to an output of a preceding stage, a second input connected to an output of the next stage and a first terminal connected to a first clock signal and a second terminal connected to a second clock signal, the stage containing a first semiconductor device switching the output of the stage between high and low values of the first clock signal, the first semiconductor device being controlled by the potential of a second node, itself connected to the output of the preceding stage across a second semiconductor device controlled by the output of the preceding stage; to a negative potential across a third semiconductor device controlled by the output of the next stage; and to the second terminal connected to the second clock signal across a first capacitance, wherein a second capacitance is mounted between the second node and the output of the next stage.

Abstract: The subject of the present invention is a shift register for an LCD, the stages of which use the Boostrap [sic] effect and can contain just three M.I.S. transistors, as well as enhancements to this circuit with four or seven MIS transistors.The advantages are the low number of components used, the increase in the lifetime of the shift register and the possibility of working with control signals having an amplitude of 5 or 10 v below that of the output signals.

Abstract: A method and system of magnetic recording of information elements on several parallel tracks whereby the recording of information elements on a track is accomplished by inducing a magnetic field having a predetermined direction in a zone on the track and, during this recording, inducing a magnetic field with a reverse direction in zones of the neighboring tracks. A winding (L0, L1, L2) of each head is coupled to at least two winding of neighboring heads. A control current transmitted to the head provides at least one current diverted towards the neighboring heads.

Abstract: System for recording/writing on a recording medium in which there are distributed, on the tracks, groups (G0) of tracks with positive continuous components and groups (G1) of tracks with negative continuous components. In reading, the values of the different signals are integrated for each track. Then, on the one hand, a first addition circuit S1 adds up the results of integration of the first tracks of each group of tracks and, secondly, a second addition circuit S2 adds up the results of integration of the last tracks of each group of tracks. A comparison circuit (CD) compares the results of additions of the two addition circuits to correct the track-following operation.

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: A magneto-optic multitrack reading head on which incident light impinges. The magneto-optic head includes a first layer of magnetic material exhibiting a Kerr effect and which partially reflects the incident light to generate a first reflection ray and which partially transmits the incident light to generate an internal ray. The magneto-optic head further includes a second layer of magnetic material and a layer of non-magnetic material, the non-magnetic layer having a thickness of one-half of a wavelength of the incident light and formed between the first and second layers of magnetic material and through which the internal ray passes. The internal ray is further reflected after passing through the layer of non-magnetic material to generate a second reflection ray parallel to and in-phase with the first reflection ray. The above structure improves the merit factor and signal-to-noise ratio of the magneto-optic reading head.

Abstract: System for recording/writing on a recording medium in which there are distributed, on the tracks, groups (G0) of tracks with positive continuous components and groups (G1) of tracks with negative continuous components. In reading, the values of the different signals are integrated for each track. Then, on the one hand, a first addition circuit S1 adds up the results of integration of the first tracks of each group of tracks and, secondly, a second addition circuit S2 adds up the results of integration of the last tracks of each group of tracks. A comparison circuit (CD) compares the results of additions of the two addition circuits to correct the track-following operation.