| 摘要 |
In video recorders where the video information is alternately recorded in oblique tracks by means of two heads, there are generally provided fine control mechanisms for centering the heads relative to the track to be followed. These mechanisms do not detect whether the two heads occupy a correct position relative to each other so that their position relative to each other may differ by an amount corresponding to one track or a group of tracks. The disclosed method of controlling the two heads so that they occupy a correct position relative to each other assumes the use of a recording medium with signals reproduced by the heads contain pilot signals such that in the case of a correct reading of two consecutive tracks, the detected pilot signals are spaced at a nominal time interval from each other, i.e. half the revolution period of the head disk. The time interval between the detection of two consecutively pilot signals is measured and if that time interval deviates from the nominal time interval by a predetermined amount, the position of the two heads relative to each other in a direction transverse to the recording tracks is corrected. |
