| 摘要 |
PURPOSE:To simplify the circuit constitution of an optical transmitter and to prevent the deterioration of the reproducibility of a signal due to waveform distortion by using a pulsized FM signal to drive a light emitting element thereby sending an optical pulse signal at the transmission side and reproducing the said pulsized FM signal at the reception side to demodulate an analog signal from a voltage pulse train. CONSTITUTION:An analog signal S1 inputted to the transmitter is converted into a pulsize FM signal having a duty ratio 50% by a pulsized FM modulation circuit 1 and converted into the optical pulse signal S3 of the same waveform by an optical signal transmission circuit 2 and then sent. The optical pulse signal S3 is received by an optical signal reception circuit 3 in the same receiver, photoelectric-converted and the pulsized FM signal is reproduced. Then the leading of the pulsized FM signal is detected by a PFM modulation circuit 4, form which the signal is converted into the PFM modulation signal S4 having the prescribed width of pulse and the PFM modulation signal S4 is demodulated into the analog signal S5 by the PFM demodulation circuit 5. Thus, the control circuit is constituted simply and the stability of operation is improved. |
