MOTION DETECTION APPARATUS EMPLOYING INFORMATION CONTAINED IN THE FREQUENCY SPECTRUM OF A TELEVISION SIGNAL

摘要

Motion detector which operates by employing information contained in the frequency spectrum of a television signal. The motion detector employs a narrow band pass filter (11) at a harmonic of the vertical sweep frequency which filter is responsive to the television signal. The output of the filter is a sine wave which has a given frequency and a constant value for a televised scene having no motion. If motion occurs then the sine wave will be amplitude modulated. This amplitude modulation is detected and processed to determine that motion exists in the televised scene and provides an output signal indicative of such motion.