Showing papers on "Closed captioning published in 1979"

Television captioning system

Abstract: Captioning of television presentations is achieved by transmitting digital data superimposed on the normal FM sound signal by modulation of an ultrasonic subcarrier and receiving the digital data at a viewer's television receiver by picking up the ultrasonic signal from the television receiver's loudspeaker; the received digital data being demodulated and applied to the television receiver as readable alphanumeric captions.