JPS5683197A - Remote controller - Google Patents

Abstract

PURPOSE:To enable stable operation against noise, by comparing the transmission time of a carrier at the transmission side with a carrier detection time at the reception side, to discriminate if a carrier is consecutively received. CONSTITUTION:The output of the detector 510 for the noise component at the point A through BPF is not kept during the time of carrier detection T2. Thus, since the continuous control signal discriminator 511 judges the absence of the control signal, the output of the discriminator 511 is at 0 level. Thus, the output D of the gate circuit 5 is at 0 level and the noise mixed with the shorter period than the time T2 is not demodulated at data. While normal control signals are received, the signal at the output point B of the detector 510 is at level 1 during the transmission time T1 of carrier, and the discriminator 511 outputs the signal of 1 level for the time of tau=T1-T2 after the time T1. Thus, the circuit 512 opens the gate by time tau, then the output D is at level 1 for the time tau. This output D is judged as normal signal.