SCIENTIFIC CONCLUSIONS INTRODUCED WITH SPRIAL FORM

摘要

Video disc record is provided with a spiral information track containing recorded representations of composite video signals. The information representations occupying the length of each convolution of the spiral depart slightly from an integral number of field intervals by a fixed amount. The departure amount is such that the information content per spiral convolution corresponds to a given integral number of line intervals plus a predetermined fraction of a line interval (other than one-half). Synchronizing information locations in successive convolutions are thus staggered in a spiral manner. Recording apparatus for forming such a record includes apparatus for maintaining the rate of rotation of a recording turntable substantially constant at a rate which differs from an integral submultiple of the field rate of the composite video signals supplied to the recorder by an appropriate small amount.