| 摘要 |
PURPOSE:To arrange the height of both rotary heads, by recording a pilot signal with a rotary head at tape halt and taking the signal output maximum obtained from the playback while changing the height of another rotary head. CONSTITUTION:A cylinder 7 has rotary heads 3,4 exclusive for playback fitted to a moving end of drive elements 5,6 and rotary heads 1,2 for recording. A magnetic tape is stopped, the rotary cylinder only is rotated and a pilot signal is recorded in a specific section of one field with one rotary head. While the reproduction is made with another rotary head than that used for recording on the magnetic tape, if the height of the both rotary heads is matched, the pilot signal is reproduced, but if the difference of height than one track-pitch or more is present, no pilot signal is reproduced. The height of playback heads is controlled with the drive elements 5,6 to a point where the pilot signal output takes a maximum. This system is suitable for VTRs with automatic tracking and special speed reproduction. |
