| 摘要 |
PURPOSE:To detect the presence of an FM signal on a tape at a high speed by detecting the envelope of an FM modulation signal recorded on a magnetic tape by means of a rotary magnetic head through the use of a fixed magnetic head. CONSTITUTION:The magnetic tape 1 runs via guide posts 8, 9 and a guide lead 10 on a running face of a head cylinder 2, the rotary magnetic heads 4, 5 record the FM modulation signal and its envelope is detected by a detecting section 12 of the fixed head 11. Thus, the presence of the FM signal on the tape 1 is detected in high speed. |
