Patents Assigned to L'Etat Francais represente par le Ministre des Postes, des Telecommunications et de l'Espace
  • Patent number: 5243260
    Abstract: Method for producing a display screen with a matrix of transistors provided with an optical mask. This method consists of depositing on a substrate (100) a layer of black polyimide (102) absorbing the visible light and followed by a layer of photosensitive resin, of insolating the resin through a mask masking the channels of the transistors to be embodied, of eliminating the zones insolated with the resin and the sub-adjacent zones of the polyimide, of depositing an ITO layer (106) on the unit, of eliminating the rest of the resin and the ITO surmounting said resin so as to form the drains/sources of the transistors, of successively depositing a layer of hydrogenated amorphous silicon (110), a layer of silicon nitride (112) and a layer of aluminium (114), then of photoengraving the stack of these layers so as to form the gate of the transistors, and finally to render passive the unit with a layer of silicon (116).
    Type: Grant
    Filed: September 19, 1991
    Date of Patent: September 7, 1993
    Assignee: L'Etat Francais, represente par le Ministre des Postes, des Telecommunications et de l'Espace (Centre National d'Etudes des Telecommunications)
    Inventors: Bruno Vinouze, Hugues Lebrun
  • Patent number: 5218637
    Abstract: According to the invention, the chip card issues a first certificate comprising its letter of credentials (Crc), an exponential (X), an optional message (M), these quantities being signed. The security module verifies the signature and in return issues a second certificate containing its letter of credentials (Crm), an exponential (Y), an optional message (M'), a cryptogram (C), these quantities being signed. A common secret key is constituted between the card and the security module by the exponentials and allows the card to interpret the cryptogram addressed to it and to act in accordance therewith.
    Type: Grant
    Filed: June 11, 1991
    Date of Patent: June 8, 1993
    Assignee: L'Etat Francais represente par le Ministre des Postes, des Telecommunications et de l'Espace
    Inventors: Didier Angebaud, Jean-Luc Giachetti, Louis Guillou, Jean-Jacques Quisquater
  • Patent number: 5184001
    Abstract: The station, in particular a terminal, comprises an oscillator (OS) having a feedback loop (1) and a station inductor element (L10) suitable for conferring a working frequency to the oscillator which varies relative to a rest frequency. The station also includes a station processor connected to the oscillator and capable of processing variations in the working frequency of the oscillator. The portable object, in particular a memory card, includes an electronic circuit which is switchable between an inactive state and an active state in which it sets up a resonant circuit tuned on a frequency which is distinct from the rest frequency while remaining suitable for being coupled inductively with the feedback loop (1) at the rest frequency. The portable object also includes an object processor capable of switching the electronic circuit as a function of the information to be transmitted to the station.
    Type: Grant
    Filed: July 11, 1991
    Date of Patent: February 2, 1993
    Assignee: L'Etat Francais represente par le Ministre des Postes, des Telecommunications et de l'Espace (Centre National d'Etudes des Telecommunications)
    Inventor: Philippe Levionnais
  • Patent number: 5177205
    Abstract: Method for obtaining an organic polycrystalline material having in particular electro-optical properties, said material obtained and an electro-optical modulator comprising said material.This method includes a stage (1) for preparing a powder having a size grading of 500 to 800 nm of an organic compound having a delocalized system of electrons .pi. and presenting a non-centrosymmetrical crystalline structure, as well as intramolecular load transfer groupings, a stage (2) for drying the powder under vacuum, a stage (3) for pre-pressing the powder under vacuum, and a hot stage (5) for the uniaxial compression of the dried powder under vacuum.This method enables polycrystalline materials to be obtained, said materials comprising elongated monocrystalline grains orientated according to a given direction.
    Type: Grant
    Filed: March 8, 1989
    Date of Patent: January 5, 1993
    Assignee: L'Etat Francais represente par le Ministre des Postes, des Telecommunications et de l'Espace (Centre National d'Etudes des Telecommunications)
    Inventors: Jean Flicstein, Denise Morin
  • Patent number: 5089870
    Abstract: An SOI MOS transistor comprises at least a highly doped lateral stripe (13, 14) of the same conductivity type as the substrate (3). This stripe extends along the edge of the substrate and of the source region (5) and is shorted with the source region through the conductive source layer (11).
    Type: Grant
    Filed: June 7, 1990
    Date of Patent: February 18, 1992
    Assignee: L'Etat Francais represente par le Ministre des Postes, des Telecommunications et de l'Espace (Centre National d'Etudes des Telecommunications)
    Inventor: Michel Haond
  • Patent number: 5083013
    Abstract: The station, in particular a terminal, comprises an oscillator (OS) having a feedback loop (1) and a station inductor element (L10) suitable for conferring a working frequency to the oscillator which varies relative to a rest frequency. The station also includes a station processor connected to the oscillator and capable of processing variations in the working frequency of the oscillator. The portable object, in particular a memory card, includes an electronic circuit which is switchable between an inactive state and an active state in which it sets up a resonant circuit tuned on a frequency which is distinct from the rest frequency while remaining suitable for being coupled inductively with the feedback loop (1) at the rest frequency. The portable object also includes an object processor capable of switching the electronic circuit as a function of the information to be transmitted to the station.
    Type: Grant
    Filed: December 18, 1989
    Date of Patent: January 21, 1992
    Assignee: L'Etat Francais represente par le Ministre des Postes, des Telecommunications et de l'Espace (Centre National d'Etudes des Telecommunications)
    Inventor: Philippe Levionnais
  • Patent number: 5081004
    Abstract: Method for producing a display screen with a matrix of transistors provided with an optical mask. This method consists of depositing on a substrate (100) a layer of black polyimide (102) absorbing the visible light and followed by a layer of photosensitive resin, of insolating the resin through a mask masking the channels of the transistors to be embodied, of eliminating the zones insolated with the resin and the sub-adjacent zones of the polyimide, of depositing an ITO layer (106) on the unit, of eliminating the rest of the resin and the ITO surmounting said resin so as to form the drains/sources of the transistors, of successively depositing a layer of hydrogenated amorphous silicon (110), a layer of silicon nitride (112) and a layer of aluminium (114), then of photoengraving the stack of these layers so as to form the grid of the transistors, and finally to render passive the unit with a layer of silicon (116).
    Type: Grant
    Filed: November 2, 1989
    Date of Patent: January 14, 1992
    Assignee: L'Etat Francais represente par le Ministre des Postes, des Telecommunications et de l'Espace (Centre National D'Etudes des Telecommunications
    Inventors: Bruno Vinouze, Hugues Lebrun
  • Patent number: 5079178
    Abstract: The process of the invention consists of subjecting a metal oxide coating (106, 108), located on a glass substrate (100), to the action of a gaseous plasma (109) containing 10 to 88% by volume of hydrogen, 2 to 30% by volume of a hydrocarbon and 10 to 50% of an inert vector gas, bringing about the formation of a polymer coating (110) on the parts of the substrate not provided with oxide, by dissocation of the gaseous mixture, and the partial chemical etching of the oxide (106, 108) by the formation of organometallic compounds.
    Type: Grant
    Filed: December 8, 1989
    Date of Patent: January 7, 1992
    Assignee: L'Etat Francais represente par le Ministre des Postes, des Telecommunications et de l'Espace (Centre National d'Etudes des Telecommunications)
    Inventors: Yannick Chouan, Jean-Luc Favennec
  • Patent number: 5074955
    Abstract: Process for the anisotropic etching of a III-V material and application to surface treatment for epitaxial growth.This process includes the step of etching a III-V material (2) by reactive ionic etching using a gaseous mixture containing by volume 20 to 30% of at least one gaseous hydrocarbon, 30 to 50% of at least one inert gas and 20 to 50% of hydrogen.Said etching can be performed locally with the aid of a Si.sub.3 N.sub.4 etching mask (4a).
    Type: Grant
    Filed: August 17, 1990
    Date of Patent: December 24, 1991
    Assignee: L'Etat Francais represente par le Ministre des Postes, des Telecommunications et de l'Espace (C.N.E.T.)
    Inventors: Loic Henry, Claude Vaudry
  • Patent number: 5063567
    Abstract: Photoreceptor for frequency-modulated optical signals. The photoreceptor consists of a semiconductor laser (10) fed clearly beyond the threshold (12). The optical signal (20) to be demodulated is injected into the laser. The voltage (V) taken at the terminals of the latter reflects the frequency difference between the frequency of the signal (F1, F2) and the actual frequency (Fo) of the laser.
    Type: Grant
    Filed: September 14, 1990
    Date of Patent: November 5, 1991
    Assignee: L'Etat Francais represente par le Ministre des Postes, des Telecommunications et de l'Espace (Centre National d'Etudes des Telecommunications)
    Inventor: Hisao Nakajima
  • Patent number: 5055739
    Abstract: A memory effect, monochromatic display of the photoconductor-electroluminescent type, includes on a substrate an electroluminescent layer and a photoconductor layer in stacked relation. The stack is interposed between two electrode systems used for exciting the electroluminescent layer, the latter having an emission spectrum overlapping the sensitivity spectrum of the photoconductor material. An optical filter is located between the electroluminescent layer and the display observer and permits the passage of that part of emission spectrum of the electroluminescent layer most useful for display purposes while blocking a region of the emission spectrum of the ambient illumination, the sensitivity spectrum of the photoconductor layer then being essentially contained in said region.
    Type: Grant
    Filed: February 8, 1990
    Date of Patent: October 8, 1991
    Assignee: L'Etat Francais represente par le Ministre des Postes, des Telecommunications et de l'Espace (Centre National d'Etudes des Telecommunications)
    Inventor: Pascal Thioulouse
  • Patent number: 5046074
    Abstract: The invention enables extremely quick and reliable recovery of the synchronization of a communication signal transmitted in a half-duplex link. Such a communication signal comprises first time intervals including useful data, and second time intervals devoid of useful data and in a given logic state. At the beginning of each of the first time intervals is included a digital synchronization pattern which is then considered as associated with the second time intervals to form synchronization words of great length. The synchronization of the communication signal is recovered by detecting the synchronization words of great length in the communication signal.
    Type: Grant
    Filed: August 16, 1989
    Date of Patent: September 3, 1991
    Assignee: L'Etat Francais represente par le Ministre des Postes, des Telecommunications et de l'Espace (Centre d'Etudes des Telecommunications)
    Inventors: Jacques Abiven, Gilles Ramel