The present invention is relative to a video signal transmitting/receiving system in which digital video signals are transmitted from a transmitter (30) to a receiver (50) using a line (9) as a transmission channel. The transmitter (30) converts the video signals to be transmitted to a bit string longer in data length than a pixel making up the video signals, allocates a plural number of the bit strings to a blanking period during which pixel data in the pixel string is not transmitted and, using these bit strings, transmits the same superposed data a plural number of times. The receiver (50) extracts the specified bit strings indicating the blanking period from the received data and performs majority processing on the results of demodulation of the extracted bit strings to decide on output data. This reduces errors in reception of supplementary data to simplify the circuit structure as well as to ameliorate the error rate.