| 摘要 |
<p>PURPOSE:To improve the reliability by using an audio tape having a prerecorded signal part comprising a low-frequency signal of a video signal between a nonrecording part and the video signal to suppress the frequency increase at high- speed scanning thereby increasing the contrast of reading level among the nonrecorded part, data and compensating frequency part. CONSTITUTION:An analog signal from the tape is transferred to a CPU as the nonrecording detecting signal and the parallel data through a program searching detector 2, a demodulator 3 and a serial I/F. The CPU synthesizes and outputs a control signal of a tape recorder by transmitting prescribed data to a control circuit 6 according to software. When the 4kHz of the data string is constituted as ''phi'' signal and the 8kHz is constituted as ''1'' signal and when the 8kHz is selected as the carrier part and high-speed search is applied, a high frequency of 40kHz-240kHz enters the program search detector and the output level is decreased. Since the frequency is obtained as 20kHz-120kHz by selecting a low frequency part of the carrier part data in a figure, a sufficient level difference is taken by the noise level of the nonrecorded part.</p> |
