| 摘要 |
PURPOSE:To increase the stability of the gain of amplification, by inserting the reference amplification signal into the facsimile signal at the transmitting side and performing the amplification gain control of the received signal based on the reference amplification signal at the receiving side. CONSTITUTION:The facsimile signal containing the reference amplification signal is transmitted to the receiving side from the transmitting side based on the sequence of each line. The received signal is supplied to a rectifying circuit 5 and a demodulating circuit 2 via an amplifying circuit 1. The facsimile signal demodulated at the circuit 2 is supplied to a decoding circuit 3. The received signal is rectified to a DC component through the circuit 5. The synchronizing code signal S of the first line is supplied to the circuit 3 and decoded to detect the section of one line and then to deliver the timing pulse (a). A gate control circuit 4 receives the pulse (a) and delivers a gate control pulse (b) to supply only the area corresponding to the signal R among the received signals to an integral network 6. The output of the circuit 6 is turned into an AGC signal. |
