| 摘要 |
PURPOSE:To correspond to the speed change of a time code in a wide range by providing a cycle measuring circuit, an operating circuit and a demodulating circuit. CONSTITUTION:The cycle measuring circuit 2 fetches the time code TC of a BPM system where an reproduction output from the tape of a tape recorder is binarized and obtains cycle data at the level change point of the time code TC one by one so as to transmit it to the operating circuit 3. The operating circuit 3 obtains the change point of respective kinds of cycle data based on present cycle data and preceding cycle data within transmitted respective kinds of data and calculates a threshold for demodulating the time code from the average value of the change points of obtained cycle data. The demodulating circuit 4 demodulates a signal corresponding to the time code based on the threshold calculated by the operating circuit 3. Thus, the signal corresponding to the synchronization change of the time code is demodulated without the PLL circuit of complicated circuit constitution. |
