| 摘要 |
PURPOSE:To make picture-recording confirmation at a real time, by recording a frequency-modulated signal on a magnetic tape and, at the same time, detecting the envelope of the frequency-modulated signal immediately after the recording on the magnetic tape by means of a fixed type magnetic head. CONSTITUTION:Electric signals are frequency-modulated and recorded on a magnetic tape 1 as inclined tracks 23 and 24 by means of a rotary type magnetic head. Simultaneously, existence/nonexistence of FM signals recorded on the magnetic tape 1 is detected by means of a fixed head 16 for detection. The azimuth angle 25 of the track 23 is set by turning the track 23 clockwise by an angle theta, and the azimuth angle 26 of the track 24 is set by turning the track 24 counterclockwise by the angle theta. The azimuth angle 27 of the head 16 is set so that angles between the azimuth angles 27 and 25 and azimuth angles 27 and 26 can become equal to each other. An FM signal S1 from the head 16 is inputted in a peak holding circuit 19 through an amplifier 17 and rectifier circuit 18 and outputted as a signal S6 after it is compared with a reference voltage. Therefore, the envelope of a frequency-modulated signal can be detected at a high speed and the confirmation of picture recording can be made at a real time.
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