| 摘要 |
The video or television signals are broken into numerous elements representing spaced portions of the video display screen along the line sweep, and imprints (electrical or optical) for each element are made in a path on a rotating medium which may be a disc, drum or belt. The lineal length of each imprint on the path is determined by the light characteristic of the video signal being recorded. Clock marks are permanently recorded in a separate path on the rotating medium. Maximum density of imprints is achieved by using an extremely narrow width of about one ten thousandth to one thousandth of an inch wide, and not only make adjacent tracks contiguous, but actually overlapping. Sound is supplied by using an unused portion of the video signal and the trailing edges of the line start pulses are convenient portions. Because the tracks may overlap or small errors in concentricity may occur that would otherwise meld together sound from two side-by-side tracks, only certain digitally spaced parts of one track are used for sound and different digitally spaced portions of another track are used. The method and apparatus permits transcribing broadcast television signals or transcribing directly from a television set and permits playback directly into a set, or if modulated by very high or ultra high frequency waves, may be broadcast as conventional television, or introduced directly into a broadcast television receiver by attachment to the antenna terminals.
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