Patents Assigned to Thorn EM plc
  • Apparatus for marking a recorded signal
    Patent number: 4963998
    Abstract: This invention relates to apparatus for marking a recorded signal. The apparatus includes means for generating and storing a marking signal comprising at least two codes which are mutually in phase quadrature. The codes are converted to analogue signal and are used to phase-shift modulate the signal to be recorded, the modulating means performing the function of a single side band modulator on the signal to be recorded.
    Type: Grant
    Filed: April 20, 1989
    Date of Patent: October 16, 1990
    Assignee: Thorn EM plc
    Inventor: Barry G. Maufe