| 摘要 |
A video recording and scanning system includes a disc-type record, and a record player, the record having both video picture signal producing indicia and synchronizing pulse producing indicia recorded on its spiral track, the length of the track-carrying signals for recording each picture being variable to permit greater compression of information on a given track with short spacings, or greater image resolution detail with long spacings, the number of the pulse indicia having a fixed ratio to the number of individual pictures recorded on the disc, the position of each pulse indicium being fixed relative to the position of the indicia for producing each picture, the record player including a scanning means, a comparison circuit and a disc speed varying means, the scanning means being mounted for relative movement along the track and producing both picture signals and pulse signals, the comparison circuit comparing the frequency of the pulse signals to a reference frequency to produce an adjustment signal, and the disc speed varying means being responsive to the adjustment signal to vary the speed at which the record track moves past the scanning head so that the variable length portions of track-carrying signals for producing one image move past the scanning means in the same period of time and produce a constant picture changing frequency which is independent of the length of the track carrying the signals for producing each picture. |
