| 摘要 |
<p>PURPOSE:To reduce skew distortion by detecting a tape tension by turning of a tension arm at the recording time and detecting the tape tension by the variance of the horizontal scanning time of a reproduced video signal at the reproducing time to control the elongation of a tape. CONSTITUTION:When a magnetic tape 8 is run, a tension arm 17 is energized clockwise of the tape tension of the tape 8, and the turning angle of the arm 17 is so set that the tape tension and the energizing force of a tension spring 20 are balanced. A tape tension detecting means 21 detects the turning angle of the arm 17 to detect the tape tension. A horizontal scanning period variance detecting means 22 detects the variance of the period of a horizontal synchronizing signal of a reproduced video signal (a) to detect the variation of the horizontal scanning period. At the recording time, a changeover switch 23 is switched to the contact R side, and the output voltage of the means 21 is supplied to a driving circuit 24, and a supply reel motor 16 is so driven that the tape tension is constant. At the reproducing time, the output of the means 22 is supplied to the circuit 24. Thus, the skew distortion is reduced.</p> |
