Abstract: A magnetoresistant transducer is described for reading very high-density a. The magnetoresistant transducer (TMRI) includes at least one magnetoresistor (MRI) of an anisotropic magnetic material placed perpendicular to the direction in which the data of a medium (SM) pass. The axis (AFAI) of easy magnetization of the magnetoresistor is normal to the medium and includes a thin, mono-range or single domain magnetic anisotropic layer (CI) normal to the medium and to the direction in which the data pass. The mono-range or single domain layer is strongly coupled magnetically with the magnetoresistor, and its axis of easy magnetization (AFACI) is normal to the medium and opposite in direction to the axis of easy magnetization of the magnetoresistor. The invention is particularly applicable to the reading of magnetic tapes and disks containing high density data.

Abstract: The invention relates to apparatus for positioning and holding a screen carrier in a serigraphic machine. The positioning and holding apparatus is essentially constituted by two parallel grooves (21, 22) machined in the screen carrier (10) and cooperating stops and a side latch mechanism on the machine. The two grooves have at least one extremity opening on the same edge (C1) of the screen carrier. In these two grooves (21, 22) are respectively mounted the two stops (23, 24) which are designed to come respectively into contact with two fixed reference pins carried by the serigraphic machine. During insertion of the screen carrier, by sliding in its plane along two sides of the serigraphic machine, the two reference pins ride in the respective slots contacting the stops when the screen carrier is inserted fully. A latch locking arrangement is provided on the machine or maintaining and holding the screen carrier in position once the reference pins are in contact with the associated stops.

Abstract: Platform comprising a principal member containing a read and/or record transducer for a data carrier and a suspension device connected on the one hand to the said principal member and on the other hand to means of supporting the platform.In accordance with the invention, the platform is characterized in that is comprises means for modifying the flow of air around all or part of the principal member and of the suspension device. A protective fairing of walls envelope the principal member to minimize turbulent effects on the transducer.

Abstract: A central sub-system of a data processing system, including an operator console controlling a service processor, is divided into several sub-units, functioning separately from each other. The sub-units include processors that are connected together and to a common controller for a common memory unit by data, address and control buses. Each sub-unit includes a configuration device that stores an appurtenance indicator derived from the service processor in response to sub-unit initialization, and enables its associated sub-unit to exchange data with the memory unit. The sub-unit having the highest priority of the sub-units attempting to access the memory units is connected to the memory unit by the controller. A single configuration memory stores an indication of the sub-units in service in the central sub-system. The configuration memory is addressed each time the memory unit is addressed by a signal indicative of the appurtenance indicator derived from the selected sub-unit.

Abstract: The user has a credit card incorporating electronic devices and/or circuits. The facility which is to be protected has an electronic device and/or circuit analogous to that of the credit card. The devices of the credit card and of the facility contain in their respective memories a secret code S, an identification code I.sub.n, and a program p. The facility which is to be protected has available a generator of a random code E which is transmitted into each of the devices when a request for access is made. The devices within the card and the facility each calculate the function R=p(S, E, I.sub.n), and a comparator situated in the facility which is to be protected compares the functions supplied by each of the devices to allow or deny access of the person to the said facility.

Abstract: The transmission of signed messages occurs between a transmitter (1) and a receiver (3) connected by a transmission line system (2). The transmitter (1) and the receiver (3) respectively comprise a coding device 7 and a decoding device 11. Means 4 situated at the transmitter supply a signature SG as a function of the message M which is to be transmitted. The message associated with its signature, as well as a common key E, are transmitted by the transmitter towards the receiver after coding by means of an intrinsic key R.sub.1. Upon being received, the message M linked with its signature SG is decoded by means of an intrinsic key R.sub.2 determined at the receiver location in such manner as to establish equality between intrinsic keys R.sub.1 and R.sub.2.

Abstract: A data byte element E located at position d in entry i of memory section M.sub.a having reference entry TR is addressed. Memory section M.sub.a is one section of a table in a data processory memory, such that each of the entries in section M.sub.a has a predetermined number (t) of elements E. Signals having values related to the values of i, t and TR of several memory sections are stored in a storage device and read out when the storage device is addressed. A signal related to the value of d is also derived as a result of read-out from the storage device. The signals having values related to the values of i, t, TR and d are combined to derive an addressing signal for element E in memory section M.sub.a of the table of the data processing memory. An address circuit for the data processing memory responds to the addressing signal to addressing element E in memory section M.sub.a.

Abstract: A magnetic tape reel is secured to a reel drive motor shaft by a device including a hub secured to the shaft, a plurality of shoes, and actuating means for thrusting the shoes against the reel and for releasing them from contact with the reel. The securing device includes a cam mounted on the shaft in combination with a locking device including the cam periphery. The locking device thrusts the shoes against the object and is operated by rotation of the motor. The cam is immobilized in rotation while the shoes are locked.

Abstract: A circuit arrangement for the compensation of voltage variations of the electrical AC polyphase power line for an AC-DC converter (3).The invention comprises a first circuit (5) for determining the voltage variations at the input of each trigger rectifier (Th.sub.1, Th.sub.2, Th.sub.3) of a converter (3) and a compensating circuit (6) for compensating the firing angle of each trigger rectifier. The compensating circuit (6) is connected to an output (7) of the first circuit (5) for determining the variations in the input voltage of each rectifier. Outputs of the compensating circuit (6) are connected to control inputs of the pulse generator (4) for controlling the firing angle of each rectifier so as to adjust the period of the firing pulses of each trigger rectifier (Th.sub.1, Th.sub.2, Th.sub.3). The invention is particularly applicable to electrical DC power supplys for data processing systems.

Abstract: A system and method for distribution of articles or services, especially adapted to be secure against use by unauthorized personel, receives first and second data carriers. Each data carrier includes a processor, data storage, and interfacing circuits. A random number generator feeds a random number to each of the data carriers which use a program to generate a resultant based on the random number, a secret code and an identification number. The secret code and identification number are stored in the data storage of each data carrier. The resultants are compared to determine if they are equal, in which case access is allowed.

Abstract: A connector for a portable object particularly adapted for credit cards having an IC chip thereon comprises an element incorporating a chamber having an opening adapted to receive the portable object along a predetermined direction. Means for grasping the portable object are contained in the chamber and actuable by the displacement of the portable object. The means for grasping the portable object comprises a first jaw and a second jaw formed by a member which is not integral with the element and cooperating with a guiding device such that it is displaced in the chamber along the predetermined direction between a stable idle position close to the opening and an operating position away from the opening. The member is tipped with respect to the portable object between the idle and operating positions.

Abstract: The invention relates to a device particularly adapted for use with the power supply of a computer for controlling the regulating facilities in an electric high-power AC-DC converter of the power supply.This control device (D) comprises a regulation (CC) control comparator connected to the storage facilities (S) of the converter and receiving a reference voltage having a "nominal" value when the converter is normally powered by an AC network and receiving a portion of the output voltage from the converter, the output of said control comparator (CC) supplying an error signal to the regulating facilities (MR) of the converter. The control device also includes facilities (R) for supplying a variable reference voltage to the control comparator (CC) so that at the moment of recovery of the network following a cutoff, the voltage at the input of the filtering facilities (F) of the converter is, at the most, equal to the output voltage of the storage facilities (S).

Abstract: A part which is attached to a support frame is pressed against a rotatable member mounted within that support frame. An element having four degrees of freedom is mounted between the support and a point on the part. A biasing element is mounted between the support and a second point on the part to urge the part against the movable member. The structure is useful in the recording of data on a magnetic recording machine and impactless magnetic printing machines.

Abstract: The invention relates to a magnetographic printing process, as well as to a achine which enables images in color to be produced on a print carrier. The machine which carries out this process comprises magnetic heads (13-1, . . . , 13-n) excited by pulses emitted by a generator (26) by means of a current calibrating means (27) to produce on the drum (10) magnetized points having different magnetizations, pigment applicator means (40, 42, 44), retouching means (41, 43), and a transfer station (45) where the pigments deposited onto the drum (10) are transferred to a paper strip (21).The electric current calibrating means is connected between the pulse generator and each of the heads so as to allow each of the current pulses emitted by the generator to be adjusted selectively to one of the p predetermined amplitude values and thus to produce on the recording surface a latent magnetic image whose magnetized points exhibit the same magnetic polarity but have different intensities of magnetization valued as J.sub.

Abstract: The invention relates to a printing process, as well as to a machine which enables images in color to be produced on a print carrier.The machine which implements said process comprises magnetic heads (13-l, . . . 13-n) energized by impulses emitted by a source (26) by means of a frequency-generating means (27) in order to produce on the drum (10) magnetized points having different sizes, pigment-applying means (40, 42, 44) retouching means, and a transfer station (45) where the pigments deposited onto the drum (1) are transferred to a strip of paper (21).

Abstract: The invention relates to a magnetographic printing process as well as to a machine which enables the production of images in two colors on a print carrier. The machine which carries out said process comprises magnetic heads (13-1 . . . , 13-n) energized by impulses emitted by a pulse generator (26) by means of a current calibrating and reversing device (27) in order to selectively produce on the drum (10) magnetized points having magnetizations of different direction and amplitude, pigment applicator means (40, 42), retouching devices (41, 43) and a transfer station (45) where the pigments deposited onto the drum (10) are transferred to a paper strip (20). The magnetized points designed to produce on the carrier images or parts thereof which must appear in one of said colors all have magnetization intensities of the same amplitude (J.sub.1) and in the same direction and a magnetic polarity which is opposite that of other magnetized points all having magnetization intensities of the same amplitude (J.sub.

Abstract: The invention relates to a printing process and machine which enables the production of two-color images on a print carrier. The machine which carries out this process consists of two applicators (40,42) placed one after the other to deposit two layers of differently colored pigments onto the magnetic drum (10). The surface of the drum has produced thereon a latent magnetic image whose magnetic points have the same intensity of magnetization, but opposite polarities, the magnetic points intended to produce powder-image parts in one of said colors being opposite to that of the points intended to produce the other parts of said image. A transfer station (44,45) is provided with a magnetic field generator (21) located upstream to the point (45) where the pigments are transferred to the print carrier (20). The magnetic-field generator (21) applies a constant magnetic field to the recording surface in a direction perpendicular to the surface.

Abstract: A magnetoresistant transducer for reading data present on the tracks of a multitrack magnetic carrier, comprises at least one magnetoresistant element perpendicular to the direction of travel of the data, and first and second magnetic screening means situated at either side of the element.The magnetoresistant transducer comprises deflecting means for deflecting the magnetic field generated by the current flowing through the element. The deflecting means are situated between the latter and the first and second screening means to intercept and deflect the magnetic field lines transmitted by the data items on the track. The deflecting means includes a plurality of mutually parallel thin magnetic blades separated from each other by thin non-magnetic laminations the thickness of which is such that the magnetic coupling between two adjacent laminations is weak. The laminations and magnetoresistances are of anisotropic material and have their axes of easy and difficult magnetization parallel to each other.

Abstract: The invention provides an electrical connection device for connecting high density contacts of large scale integrated circuits (LSI) and serves to establish electrical connection between the contact areas (15) of the circuit network (14) on a substrate (11) for supporting integrated circuit devices (12) and the contact pads (18) of a conductor network (17) on a printed circuit card (13). The electric connection device comprises a plurality of conductive elements disposed within a housing (26) extending in a given direction. The conductive elements are electrically insulated one from the other and have contacts which are exposed through slots in the housing to connect to the areas (15) and pads (18). The conductive elements (29) are stacked in the given direction and are formed each with a conductor sheet (30) provided with two contact surfaces (31a, 32a) elastically movable in a plane normal to the given direction independently of the surfaces of contact of neighboring sheets.

Abstract: A connector for a portable object particularly adapted for credit cards having an IC chip thereon comprises an element incorporating a chamber having an opening adapted to receive the portable object along a predetermined direction. Means for grasping the portable object are contained in the chamber and actuable by the displacement of the portable object. The means for grasping the portable object comprises a first jaw and a second jaw formed by a member which is not integral with the element and cooperating with a guiding device such that it is displaced in the chamber along the predetermined direction between a stable idle position close to the opening and an operating position away from the opening. The member is tipped with respect to the portable object between the idle and operating positions.