Patents by Inventor Bertrand LeDu

Bertrand LeDu has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Optical beam switching device and telephone exchange comprising a device of this kind
    Patent number: 4543662
    Abstract: The invention relates to switches enabling the connection by an optical method of at least one of the circuits of a set of input circuits to at least one circuit of a set of output circuits. It consists in illuminating a photosensitive medium with parallel input beams coming from a set of input circuits. The input beams are then diffracted on strata inscribed on the medium to reach one of the circuits of a set of photoreceptor circuits. The strata are inscribed by interference of two inscribing beams of which the wavelength differs from that of the input beams; the wavelength of these input beams not lying within the range of spectral sensitivity of the photosensitive medium.
    Type: Grant
    Filed: September 24, 1982
    Date of Patent: September 24, 1985
    Assignee: Thomson-CSF
    Inventors: Jean Pierre Huignard, Bertrand LeDu