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  • System for automatically correcting the duty factor of the carrier wave arising from reading-out a data carrier
    Patent number: 4142208
    Abstract: The present invention relates to the read-out of a data carrier having a track along which there is transcribed an angularly modulated carrier wave. In accordance with the present invention, there is provided a system for processing the read-out signal, which uses a feedback loop correcting the duty factor of a restored rectangular waveform when its value deviates from the value 0.5.
    Type: Grant
    Filed: July 15, 1977
    Date of Patent: February 27, 1979
    Assignee: Thomson-Brandt
    Inventors: Pierre Oprandi, Jean-Claude Lehureau, Claude Puech, Jean-Paul Peltier, Francois Le Carvennec, Jean-Pierre Lacotte, Claude Bricot
  • Telecinema system using electroluminescent diodes
    Patent number: 3943559
    Abstract: A cinematographic film to be reproduced by television is driven at constant speed in synchronism with the sweep cycle of one or more camera tubes each positioned to pick up images projected upon a receiving surface thereof whose luminous persistence equals at least a sweep cycle. The film is periodically transluminated, during the retrace phase of the scanning beam, by a light pulse emitted by an electroluminescent diode -- or by a cluster of such diodes operating on different wavelengths -- defining a quasi-pinpoint light source, the diode being excited by an energizing pulse whose length does not exceed the duration of a line scan of the camera tube.
    Type: Grant
    Filed: April 22, 1974
    Date of Patent: March 9, 1976
    Assignee: Thomson-CSF
    Inventors: Luigi D'Auria, Guy Chevalier, Michel Favreau, Jean Pierre Huignard, Jean Pierre Lacotte, Claude Puech
  • An optical information recording system in which the energy when transmitted to the recording layer is constant
    Patent number: 4051329
    Abstract: The invention relates to a system optically recording information, by the insolation of a photosensitive layer deposited on a substrate, on a track of substantially constant width. The system comprises a device for controlling the energy emitted by the source in response to the non-uniformity of the reflexion coefficient of said surface, said control device being such that the energy actually transmitted to the photosensitive layer is constant when the modulation signal has the value 1.
    Type: Grant
    Filed: March 16, 1976
    Date of Patent: September 27, 1977
    Assignee: Thomson-Brandt
    Inventors: Bruno Blondet, Sylvain Kretschmer, Jean Pierre Lacotte, Jean Paul Peltier
  • Process for manufacturing optical disks by pressing
    Patent number: 4659407
    Abstract: The invention provides a process for manufacturing optical disks by pressing and disks obtained by such a process, for improving the inherent flatness of the optical disk of the thick type, obtained by a process of pressing between a recorded master and another master, recorded or not depending on whether it is a question of a single or double side disk, this latter being formed from a stack of at least two thin sheets of thermoformable material subjected to a pressure-temperature cycle after which bonding together of the sheets and duplication of the information from the masters for information recording are obtained.
    Type: Grant
    Filed: July 2, 1984
    Date of Patent: April 21, 1987
    Assignee: Thomson-CSF
    Inventors: Jean-Pierre Lacotte, Sylvain Kretschmer, Pierre Oprandi, Georges Broussaud
  • Apparatus and process for recording with variable correction of a television signal having three components
    Patent number: 4170022
    Abstract: A process for recording on a video-disc a television signal comprising a luminance signal, a chrominance signal, and a sound signal, wherein these three signals modulate respectively three carrier-waves. The three modulated carrier-waves are added and then optically recorded onto said video-disc along a spiral track. The level of these three modulated carrier-waves are each processed according to their own correction parameters related to the distance of the recording point from the center of the video-disc, thus allowing the disc to be later read without any correction processing during reading out.
    Type: Grant
    Filed: February 10, 1978
    Date of Patent: October 2, 1979
    Assignee: Thomson-Brandt
    Inventors: Sylvain Kretschmer, Jean-Pierre Lacotte, Pierre Oprandi
  • Method apparatus and record for distributing information in the form of color images
    Patent number: 4001874
    Abstract: Three superimposed microholograms, corresponding respectively to the luminance, red chrominance and blue chrominance images, are recorded in respect of each color image. At the time of read-out, the illuminating beam is switched, at the rate of the line-scan function, between three separate positions and projects the above images on a single solid state vidicon. The read-out device can be adapted to an ordinary commercial color T.V. receiver.
    Type: Grant
    Filed: September 13, 1974
    Date of Patent: January 4, 1977
    Assignee: Thomson-Brandt
    Inventor: Jean Pierre Lacotte
  • Process for producing information supports capable of being optically read by variations in absorption
    Patent number: 4888266
    Abstract: The invention relates to a process for producing supports intended for the optical recording and reading of information. A layer containing a diazo compound is deposited onto a metallized substrate. Recording is obtained by exposing the support to light through a mask, the exposed zones of the layer of diazo compound being decomposed. Dry development in ammonia vapors shows up transparent zones and opaque zones corresponding to the information.
    Type: Grant
    Filed: March 13, 1987
    Date of Patent: December 19, 1989
    Assignee: Thomson Brandt
    Inventors: Jean-Pierre Lacotte, Claude Puech
  • Method for the manufacture of flexible disks
    Patent number: 4387068
    Abstract: Method for the manufacture of flexible disks from engraved moulds by means of a compression press comprising starting with a roll of plastic material and bringing a strip of material between the open plates of a compression press without making a preliminary hole in said strip. A preliminary hole is made during the closing of the plates by means of a first punch matched to a complementary punch, said punches serving as centering means for the two moulds, then by the guidance of the first punch in the complimentary punch for the centering of the moulds with respect to one another. The central hole is cut when the plates are closed by means of the complementary punch which is maintained in the raised position throughout the end of the pressing cycle.
    Type: Grant
    Filed: December 22, 1981
    Date of Patent: June 7, 1983
    Assignee: Thomson-CSF
    Inventors: Raymond Llabres, Robert Antoine, Jean-Pierre Lacotte, Charles Marchi
  • Optical sensor for focusing control
    Patent number: 4482803
    Abstract: An optical sensor for delivering error signals in order to control focusing of a lens on a movable recording medium or optical memory and more particularly a videodisk comprises a laser for producing a beam which is focused at a point S.sub.1. The divergent beam which proceeds from the point S.sub.1 is reflected from the face AB of a prism and is focused at a point S.sub.2. If the point S.sub.2 is located in the plane of the movable recording medium or so-called memory plane, the beam reflected from the memory plane is autocollimated and passes back through the focusing lens. A part of the beam enters the prism through the face AB, then emerges through the face AC and a circular light spot is formed in the plane corresponding to the circle of least confusion. If the point S.sub.2 is not located in the memory plane, the light spot is deformed and these deformations are detected by four juxtaposed cells placed in the plane of the circle of least confusion.
    Type: Grant
    Filed: March 22, 1982
    Date of Patent: November 13, 1984
    Assignee: Thomson-CSF
    Inventors: Jean-Pierre Lacotte, Bernard Fichot, Gilles Troude
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