To provide a signal transmission device, a signal transmission method and a display system using them for preventing concentration of the frequency of a radiated electromagnetic wave in a specific frequency range, and for suppressing the influence of missampling.

Bit widths of signals to be transferred are made unequal by using a delay element 204 and a logic circuit 205 in a transmission device 2 based on a clock signal, and the signals are assigned and transmitted by a multiplexer 202. Similarly, the signals are reconverted by using a delay element 604, a logic circuit 605 and a shift register 602 in a reception device 3.