Abstract: An uncooled thermal matrix detector having a given spectral sensitivity range and being formed from pixels which are thermally insulated from each other, each pixel including an absorbing element which is thermosensitive in the spectral sensitivity range. The thermal matrix detector also includes on its face, turned toward the incident radiation to be detected, of each thermosensitive absorbing element, a biperiodic grating of elementary blocks limiting the viewing angle of the detector, the pitch of the grating being less than the mean wavelength of the spectral sensitivity range. The thermal matrix detector can be applied to so-called BLIP uncooled thermal detectors.

Abstract: An infrared imaging device including a quantum device positioned and configured to detect infrared transmission at ambient temperature, a cooler thermally coupled to the quantum device, and controller for controlling the cooler based on a function of plural image-taking parameters as a command.

Abstract: A driving device for driving a recording apparatus for selective recording of audio/video sequences, which is to actuate the recording apparatus at a precise instant of a beginning or of an ending of the audio/video sequence to be recorded. The driving device reduces picture datum from at least one reference picture belonging to the sequence to be recorded and a memory stores the reduced reference picture datum. A comparator compares the stored reduced reference datum with reduced picture data picked up from the set of picture sequences. A controller controls the recording apparatus to be activated to begin recording at the time the comparator detects a recognition of a picture similar to the stored reduced reference datum in the set of picture sequences.

Abstract: The disclosure relates to the recognition of sequences of multidimensional images and, notably, of image signals. The disclosed device includes, for each of said sequences to be recognized, a first circuit for the correlation of vectors representing the signal with a masking vector determined from the vectors representing the sequence to be recognized, producing a series of values corresponding to the degree of similarity of the two correlated vectors, a second circuit for the correlation of a sequence of the series of values with a reference sequence determined from the vectors forming said sequence to be recognized, producing values that correspond to the degree of similarity of the two correlated sequences, and a circuit for deciding on the validity of the recognition, by comparison of the values corresponding to the degree of similarity of the two correlated sequences with a threshold value.

Abstract: In an imaging process and system by transillumination of a medium illuminated by transparency by a beam, an acoustic transducer emits an acoustic wave in the medium which interferes with the beam. The frequency of the light passing through the medium is then shifted from the value of the frequency of the acoustic wave. A collimating device whose object focus is located at the intersection of the acoustic wave and the light beam collects the light diffused by the medium.

Abstract: The apparatus comprises an X-ray source (6) to generate a beam of radiations (7) through an object (4) or the body of a patient to be examined and a multichannel detector (8) to provide information concerning the intensity of the radiation retransmitted by the object examined. Both the source and detector are mounted on a rotor (2) integral with the stator (1) which surrounds the object (4) examined. It also comprises at least one lateral diffusion light guide (14, 15) wound round the rotor (2) or on the internal surface of the stator (1) to transmit optically between optical receiver and emitter means (9, 10) of the rotor (2) and corresponding optical means (16, 17) of the stator (1), the information provided by the multichannel detector (8) and the control information of the X-ray source (6).

Abstract: The apparatus comprises an X-ray source (6) to generate a beam of radiations (7) through an object (4) or the body of a patient to be examined and a multichannel detector (8) to provide information concerning the intensity of the radiation retransmitted by the object examined. Both the source and the detector are mounted on a rotor (2) integral with the stator (1) which surrounds the object (4) examined. It also comprises at least one lateral diffusion light guide (14, 15) wound round the rotor (2) or on the internal surface of the stator (1) to transmit optically between optical receiver and emitter means (9, 10) of the rotor (2) and corresponding optical means (16, 17) of the stator (1), the information provided by the multichannel detector (8) and the control information of the X-ray source (6).

Abstract: The device comprises a sensor with a mirror coupled to a diaphragm used to shift the mirror according to the patient's heart and thorax movements. A light generator illuminates the mirror. An electro-optical detector converts the intensity of the light rays reflected by the mirror into an electrical signal and a processing circuit generates output signals indicative of heart and respiratory movements.

Abstract: The network comprises several memory elements made of ferroelectric polymer, arranged in a matrix organization at the intersections of row and column electrodes. Each memory element (Mij) memorizes a synaptic coefficient a.sub.ij of the network which may be restored by pyroelectric effect on the corresponding column of the network. Amplifier circuits, respectively connected to the columns, give a voltage which is equal to the sum, to which a sign is assigned, of the products of the synaptic coefficients by the voltage components applied to each of the lines of the network.

Abstract: The diaphragm comprises at least one chamber in which there flows a deformable material that attenuates the radiation beam, the chamber being shaped so that the attenuating material can be introduced from outside the chamber and so that it can surround the passage zone of the beam inside the chamber in such a way that the surface of the passage zone varies constantly with the volume of the material present in the chamber.

Abstract: An embodiment of the electrostatic image sensor comprises essentially two electrodes, one layer of photoconductive material and one dielectric layer comprising an electret designed to polarize the photoconductive layer without requiring a voltage source during the recording of an image. During a recording stage, a change-over switch short-circuits the electrodes. Photocarriers are released by the X-rays that have crossed an object to be radiographed. The said photocarriers move in the electrical field created by the electret and tend to cancel the electrical field at the interface between the two layers. During a reading stage, the change-over switch connects the electrodes to the inputs of a current amplifer while a light beam scans the layer of photoconductive material. The photocarriers move and completely cancel the electrical field at every point of the interface between the two layers. The current detected by the amplifier makes it possible to display an image on a cathode ray tube.

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.

Abstract: The device can be used for the displacement of light lines above determined zones of a surface and for the optical identification of these zones. It comprises one or more lateral diffusion light guides arranged parallel to the surface, coupled by one end to a light source and to controlling means in order to selectively illuminate each zone of the surface by means of at least one light guide.

Abstract: Image sensor with memory and, more especially, image sensor with reading by thermal effect.This sensor comprises mainly a layer of a photoconductive material and a layer of a transparent material, the impedance of which varies with the temperature, these two layers being comprised between two electrodes. Furthermore, a voltage generator can be connected to the electrodes during the recording when the device is illuminated. Finally, a charge amplifier can be used to detect a current when the unit is heated.

Abstract: According to the invention, the dipolar orientation of an object made of material adapted to present piezoelectric properties is obtained by exposing at least one of the faces of the object to a jet of charged microparticles in order to create therein a sufficient electrical field to obtain the said orientation, and in a variant of the invention, a direct polarization is carried out by displacing a film in front of at least one generator of charged microparticles, this invention applying in particular to the production of film in a piezoelectric polymer or copolymer.

Abstract: The invention relates to dielectric materials formed from polymers and having high dielectric permittivity.The invention provides alloys of ferroelectric polymers with different Curie temperatures, these alloys optimizing the dielectric properties over an extensive temperature and frequency range.

Abstract: A composite co-laminated piezoelectric transducer with at least one layer of polymeric substance capable of acquiring piezoelectric properties when co-laminated in the presence of an electrical field, the layer being adjacent to a conductive material acting as an electrode. According to the invention the conductive material is a polymeric substance.

Abstract: A piezoelectric transducer including a polarized piezoelectric material film, which also has a reinforcing material incorporated into the mass and which prevents any deformation of the film in certain given directions.The invention also relates to a pressure sensor using such a transducer.This sensor can be used both as a pressure sensor and as a pressure gradient measuring device.

Abstract: A telephone transducer having a body and a spacer for securing a piezoelectric diaphragm and a printed circuit, wherein the body and the spacer are made with electrically conducting material to carry out the connections between the diaphragm and the printed circuit. The diaphragm can be made of polyvinylidene fluoride or polyvinylidene fluoride copolymer.

Abstract: In a piezoelectric microphone or hydrophone, the elastic structure which reacts directly to the acoustic pressure is formed of piezoelectric polymer. The electroacoustic transducer according to the invention makes use of an elastic structure in the form of a rim clamped plate having at least one incurvation and covered on at least one of its two faces with electrodes connected to an impedance-matching circuit.