Signal Processing in the Philips ‘VLP’ System
W. Van Den Bussche, Ad H. Hoogendijk, J. H. Wessels · Journal of the SMPTE · 1974
On the ‘VLP’ record there is a single information track in which all the information is stored for the reproduction of a colour-television programme with sound. The photographic process used for writing the information on to the master record is highly nonlinear, and can therefore only be used for recording a signal with just two levels. The information can then only be present in variations in the distances between successive transitions from one level to the other. A system of coding will therefore be necessary if four or five signals are to be recorded simultaneously in this way (brightness, two colour signals and one or two sound signals).