Abstract: A liquid crystal composition comprising a low molecular weight liquid crystal in the interior of which a cross-linking network is formed by polymerization of a prepolymer of formula I: ##STR1## X being a non-mesogenic bivalent radical, the free bonds of which form an angle smaller than 180.degree.;B.sub.1 and B.sub.2 being rigid cyclic groups which would confer liquid crystal properties to the prepolymer if X was such that=180.degree..R.sub.1 and R.sub.2 being the same or different, each representing an optionally substituted alkyl, alkoxy, arylalkyl or aralalkoxy chain;A.sub.1 and A.sub.2 being the same or different, each representing a reactive polymerizable function. Display cells comprising the liquid crystal composition having a low commutation voltage.

Abstract: The invention relates to a variable transparency electro-optical device comprising: at least one lens formed by an electro-optical cell (4) comprising a first plate (6) and a second plate (8) each provided with a control electrode (14, 16) and a sealing frame (10) interposed between the two plates to form a sealed volume enclosing an electro-optical material (12), voltage generating means (18) connected to said electrodes to apply a variable voltage to said material in order to automatically or manually vary the transmission of the cell (4) as a function of the ambient light. According to the invention the cell (4) comprises at least one element (6) charged with a photochromic substance having an absorption that varies in reversible manner as a function of the intensity of the light impinging on said cell. The invention has particular applications in devices for protecting the eyes.

Abstract: Microcontactor able to be activated by a magnet comprising a flexible beam (5) in one or more conducting materials (13, 14, 15), having one end (4) attached to an insulating substrate (1) via the intermediary of a foot (3), and one free distal end (6) positioned above a contact stud (2) arranged on said substrate (1), said foot (3) and stud (2) being composed of conducting materials and provided with connecting means (7, 8, 9, 10) to an external electronic circuit, and said beam (5) being at least partly composed of a ferromagnetic material in which the beam (5), the foot (3) and the stud (2) are elements formed by electrodeposition of conducting materials from two areas (9, 10) of the substrate, said electrodeposition being carried out through a succession of masks (20, 30, 40) which are subsequently removed.

Abstract: The piezo-electric device (9) which connects a glass (8) to a movement (3) of the timepiece (1) is arranged in such a way as to deform in flexion in response to an exciting signal applied to its electrodes. The attachment zones (9a,9b) of this device (9) to this glass (8) and respectively to this movement (3) are distinct one from the other when the timepiece (1) is looked at in a direction perpendicular to the planes of the principal faces of the device (9). Thanks to this arrangement, the sound produced by the displacement of the glass (8) when the exciting signal is applied to the electrodes of the piezo-electric device (9) is more intense than in a known timepiece.

Abstract: A device in three separable modules, for the transdermic administration of drugs by electrophoresis or iontophoresis, comprises a first active module provided with at least one system of elecrodes and one drug reservoir, a second power module provided with a power supply and a third electronic module provided with an electronic circuit, control organs and a display screen, in which the power module is situated between the two other modules and comprises, in addition to the power supply formed by one or more batteries, mechanical assembly means and electrical connection or interconnection means with the two other modules means for attaching the device to the body of a patient.

Abstract: According to this method the longitude of the place where one is situated on the surface of the earth is determined by comparing the local time with the time of a reference time zone, and the latitude of the place where one is situated is determined by measuring the inclination of the earth's magnetic field in relation to the horizontal.

Abstract: The composite wall comprises a first sheet and second sheet separated by an intermediate layer as well as an ultrasonic detection device placed on a face of said second sheet and comprising a transducer element able to emit an incidental ultrasonic signal of frequence f, and able to receive an ultrasonic signal reflected on a face of said first sheet. The intermediate layer comprises at least facing the transducer element, an inserted element whose two faces are respectively in close contact with the first and second sheets. Further, the frequence f of the transducer element satisfies the following relationships:f.apprxeq.K.sub.1. V.sub.1 /2e.sub.1 .apprxeq.K.sub.2.V.sub.2 /2e.sub.2 .apprxeq.K.sub.3.V.sub.3 /2e.sub.3where K.sub.1, K.sub.2 and K.sub.3 are defined integers, e.sub.1, e.sub.2 and e.sub.3 are respectively the thickness of the first sheet, the second sheet and the inserted element, and V.sub.1, V.sub.2 and V.sub.

Abstract: Watch comprising an arrangement for detecting the direction of the terrestrial magnetic north formed by a permanent magnet and at least two magnetic sensors (34, 36) arranged for detecting the flux of the magnetic field of the magnet. The watch moreover comprises electronic management and control means serving, as a function of the signals coming from the two sensors, to control indicating means (16) arranged so as to indicate either a selected geographic azimuth or the direction of a predefined locality, in particular Mecca.

Abstract: Method of manufacturing an electrical connection, and connection thus obtained between a strip of a plastic material (1) having a conductive coating on a single face (5) and a second conductor (15) positioned on the non-conductive side (3) of said strip consisting of forming into a loop the lug (7), formed by the end portion of said strip, by thermoforming between two parallel cylinders of which at least one is heated, driven in rotation to come to press the non-conductive face of the lug (7) against a non-conductive portion of the strip.

Abstract: A universal timepiece (10) having a manually operable outer ring (33) for selecting one of twenty-four time zones, where a display indicates the time of the time zone selected. For this purpose a device for detecting the rotational position of the outer ring (33) is provided which has a special arrangement of permanent magnets (39a-j) in the outer ring (33) and of magnetic switches (27a-h) in the timepiece casing (11, 12) in a specific number as well as evaluating electronics in the timepiece movement (21). The permanent magnets (39a-j) determine the binary statuses of the magnetic switches (27a-h), which are interpreted together as a signal or as a status pattern. The special arrangement of the magnetic switches (27a-h) and the permanent magnets (39a-j) effect for each rotational position an intrinsic status pattern different in each case from the others which permits a clear indication of the selected rotational position of the outer ring (33).

Abstract: An ultrasonic measuring apparatus that includes an ultrasonic transducer for emitting ultrasonic pulses at a predetermined repetition frequency towards an object having a plurality of walls such as a blood vessel, receiving echoes reflected from such walls, and producing an echo signal having a plurality of elementary echo components (E.sub.ant, E.sub.post). A digitizer digitizes the echo signal into a series of digital values that are stored in a buffer memory under control of a circuit. A computer transfers the series of digital values stored in the buffer memory into a memory. The computer is programmed to process the digital values stored in the memory in the period between consecutive pulses and to remove a group of the digital values digitized between consecutive elementary components (E.sub.ant, E.sub.post) from those digital values to be treated between such consecutive pulses.

Abstract: An electronic timepiece having an analog or digital display delivering time information in silent, tactile manner in which the control elements (L, C, B.sub.1, B.sub.2) provided on the exterior of a closed housing cooperate via the intermediary of an interpretation circuit with the electronic coding means (22) to drive the vibration generating device (23) by means of pulse strings to emit vibration strings representative of an item of time information or of the accuracy of a time instruction or non-time instruction introduced by means of said control elements.The timepiece presents a conventional appearance, but enables a visually impaired person to know the time, to correct the internal time and to set an alarm time.

Abstract: A watch including an arrangement (14) indicating the terrestrial magnetic north. Such terrestrial magnetic north indicating arrangement is fitted into the watch case (32) in a lateral peripheral region of the horological movement (2). Specifically, the terrestrial magnetic north indicating arrangement comprises a permanent magnet (16) mounted on a shaft (18) and a direction indicator (24) fixed to such shaft. In accordance with three specific embodiments, the watch according to the invention enables, firstly, indication of the north direction, secondly, any direction whatsoever permitting the user to follow a predetermined direction and, thirdly, the direction of Mecca from at least one place on the terrestrial globe where such user is located.

Abstract: An ultrasonic detection device having a transducer (10) for emitting and receiving ultrasonic pulses through a windshield, and producing an echo signal (40,50) representative of the reflected pulses. The detection device also includes an amplifier (23) for amplifying the echo signals (40,50) by a selectable gain, an integrating circuit (26) for integrating each of the echo signals (40,50) during a selected time period (62,63) so as to produce an integral value, amplifier control circuitry (27,28) measuring the integral value and selecting the gain of the amplifier so as to maintain the integral value at a steady-state value, and the temporal deviation of the integral value from the steady-state value is measured to determine if it is greater than a predetermined threshold value. The invention may be used to detect water on a windscreen and to control the operation of a windscreen cleaning system.

Abstract: The invention concerns a diagnostic circuit for amperometrically determining the current passing through a sensor (41). The circuit comprises a current source (V+, 46) for passing a constant DC current through said sensor (41), switching means (45) for selectively operating said current source, comparing means (42) for comparing the potential difference (V.sub.BS) across said sensor to a reference voltage (V.sub.ref), and producing a control signal (D) control means (44) for controlling said switching means (45) in response to said control signal (D), and timing means (48,49) for measuring the cumulative time during which said switching signal (Q) has said first logic level during a selected time interval, so as to provide an output signal (50) indicative of a mean value of current (I.sub.bs ave) passing through said sensor (41).

Abstract: A measurement arrangement, in particular for measuring the proportion of glucose in the blood, which is intended to be associated with a removable sensor including a plurality of single use active zones includes a cutting arrangement (44, 64, 66, 68, 70) serving to cut off the removable sensor (52) introduced into the measurement arrangement. The cutting arrangement comprises a lever (44), a crank (66) and a blade (70) fixed on the lever.

Abstract: The hands of the timepiece are connected to a barrel spring which also drives the rotor of a generator at a speed greater than a desired speed Vc. The electric energy supplied by the generator energizes a slaving circuit that includes a transistor which short-circuits the coil of the generator and thus brakes the rotor down to a speed less than the desired speed Vc when a comparator indicates that this rotor is ahead with respect to its theoretical angular position. A limiting circuit limits the duration of the braking action of the rotor to a fraction of the period of the a.c. voltage supplied by the generator. This arrangement ensures that the slaving circuit is adequately energized even if the rotor is substantially ahead.

Abstract: The present invention concerns a measuring device, notably for measuring the level of glucose in blood, intended to be used with a removable sensor comprising at least one active zone. In particular, the invention concerns the electrical connection between the measuring device and the removable sensor. Each electrical contact surface of the removable sensor is connected to two electrical contact organs to enable the condition of the electrical contacts between these electrical contact organs and the corresponding contact surfaces to be checked before a measurement is carried out.

Abstract: An analogue timepiece capable of indicting a pressure variation, such as that of atmospheric pressure, comprises at least two hands (2, 3) for providing time information, a watch movement (12) for driving the hands and a pressure sensor (13, 13a) for measuring the atmospheric pressure variation. One of the hands (2, 3) indicates the measured pressure variation while one of the others of said hands (3, 3) indicates at the same time a weather forecast as a function of the variation.

Abstract: An electronic display arrangement comprises at least one electro-optical display means, as for example a liquid crystal cell, a certain number of elementary patterns associated with the electro-optical display means, such elementary patterns for the most part conforming to and being based on a series of stylized and selected alpha-numeric characters in the form of a composite mosaic-type structure the grid of which is formed by the patterns which exhibit heterogeneous and complementary contours arranged so as to nest into one another in a manner similar to that of a puzzle, the arrangement being characterized in that the mosaic is divided up by optically passive bands which partially cover over certain of the elementary patterns and form a cutup of the mosaic. The electronic display arrangement is applicable to panels for displaying alpha-numeric characters for the visualization of messages in public places such as railway or airport halls.