Digital video modulation and demodulation system
Apparatus using a light sensing system for sensing time modulated information from a light emitting device Patent #: 4329684
ApplicationNo. 06/718679 filed on 04/01/1985
US Classes:348/61, SPECIAL APPLICATIONS345/179, Stylus434/323, Cathode ray screen display included in examining means463/9In a game requiring strategy or problem solving by a participant (e.g., problem eliciting response, puzzle, etc.)
ExaminersPrimary: Groody, James J.
Assistant: Peng, John K.
Attorney, Agent or Firm
International ClassesG09B 5/00 (20060101)
G09B 5/06 (20060101)
H04N 7/08 (20060101)
AbstractAn optical decoder to permit differentiating between at least two flashing spots displayed on a cathode ray tube screen is provided by a photosensor and an electrical circuit which is responsive to the absence of flashes during a flashing sequence which is different for the two spots and not distinguishable by the naked eye.