| 摘要 |
PURPOSE:To attain low power consumption by transmitting two kinds of pulses having different pulse width in response to the rising and falling of a transmission data signal and allowing a reception side to invert the polarity of a binary level according to the pulse width of the reception pulse to eliminate the need for a complicated coding/decoding circuit. CONSTITUTION:An output signal (a) of a transmission circuit 1 for start-stop data is inputted to a signal converting circuit 2, and differentiation circuits 2a, 2b of the circuit 2 detect the rising and falling of the signal (a). An output of the circuits 2a, 2b triggers monostable multivibrator circuits 3a, 3b, an OR gate 5 generates two kinds of pulses in response to the rising falling of different pulse width and transmits it from a light emitting section 6 to a photodetection section 7. The signal is converted into an electric signal by the photodetector section 7 and the result is inputted to a signal regenerating circuit 3. Then monostable multivibrator circuits 6a, 6b, AND gates 7a, 7b and an FF9 of the circuit 3 process the signal, demodulates the signal in response to the pulse width of the reception pulse to simplify the system constitution thereby decreasing the power consumption. |
