| 摘要 |
PURPOSE:To widen the allowable range of a reference frequency and also to reduce power consumption by sending digital signals while distinguishing between both pieces of information of ''0'' and ''1'' judging from an interval between two pulses and then by modulating those pulses at a specific frequency. CONSTITUTION:Transmission circuit 1 converts the transmission instruction into a transmission code as shown in the figure, and it is modulated into a photo signal by light emitting diode 3 before being transmitted. At the reception side, the transmitted photo signal is detected by photo diode 4 and sent to reception circuit 2, which decodes the transmission instruction by judging the pulse interval of the transmission signal. For example, it is only required here to judge that the pulse interval of pulses of 2m sec in interval is less than 3m sec at the reception side and that of pulses of 4m sec is more than 3m sec, so that allowable ranges of reference frequencies of the transmission and reception sides. |
