摘要 |
PURPOSE:To photograph simultaneously the same object with plural devices without a fear of erroneous detection of optical beams from another device by using, what is called, an M-series generator using FFs and an exclusive OR as a phase generator. CONSTITUTION:A random phase generator 20 is provided in the output of an oscillator 13. What is called, the M-series generator using FFs 21-24 and an exclusive OR25 is used as the generator 20. When a clock signal is inputted, the output signalf from the random phase genertor 20 from which the output of a random phase is taken out is supplied to a light emitting diode 5 to modulate the emitted light, and this output signal is supplied to synchronous detecting circuits 9a and 9b. Consequently, the phase difference for synchronous detection of the optical beam from another video camera is random and is eliminated by integrators 10a and 10b in the succeeding stage to prevent the malfunction. Thus, individual devices are operated normally even if the same object is photographed by many devices. |