Patents Assigned to Bull S.A. (Societe Anonyme)
  • Patent number: 4771350
    Abstract: A magnetic transducer for writing and reading data on a perpendicular recording carrier such as a magnetic disk includes a writing pole (MPOLI.sub.1) perpendicular to the recording carrier and a coil (BOBI.sub.1) magnetically coupled to a writing pole, each turn cross section of the coil being perpendicular to the carrier. The coil comprises a spiral with a flat development parallel to the carrier, disposed about and in the vicinity of the end of the writing pole (MPOLI.sub.1) that is located facing the carrier.
    Type: Grant
    Filed: December 24, 1985
    Date of Patent: September 13, 1988
    Assignee: Bull S.A. (Societe Anonyme)
    Inventor: Jacques Desserre
  • Patent number: 4714828
    Abstract: An optoelectronic transducer is proposed which includes a PIN diode (2) that delivers a current that is proportional to a light signal that is received. The diode is connected to the input of an inverting amplifier (4) that delivers a voltage signal v.sub.s. A negative feedback means of the transfer impedance type (6) is connected across the inverting amplifier. The transducer further includes a stabilizing means (8) for the amplifier gain and a temperature drift compensating means (10) for compensating for the drift in amplifier temperature. The stabilizing means (8) includes a detector (26, 28, 32) for the high peak of the signal v.sub.s, and the temperature drift compensating means (10) includes a filter means (38) for producing the means value v.sub.m of the signal v.sub.s, and a comparator (40) that receives the signals v.sub.s and v.sub.m and delivers a signal that reproduces the interference of the light signal that has been received.
    Type: Grant
    Filed: March 14, 1986
    Date of Patent: December 22, 1987
    Assignee: Bull S.A. (Societe Anonyme)
    Inventors: Claude Bacou, Rene Baptiste, Henri Feissel, Gilbert Takats, Christian Cabrol