A transmission device comprising: a controller configured to select one of a first operation mode, a second operation mode and a third operation mode, wherein in the first operation mode data are transmitted by means of a differential signal, in the second operation mode data are transmitted by means of a three phase signal and in the third operation mode data are trasnmitted by means of a single-phase signal; a first selector configured to, in the first operation mode, alternately select one of a first signal and a second signal, and output the selected one of the first signal and the second signal; a second selector configured to, in the first operation mode, alternately select one of an inversion signal of the first signal, when the first selector selects the first signal, and an inversion signal of the second signal, when the first selector selects the second signal, and output the selected one of the inversion signal of the first signal and the inversion signal of the second signal; a first driver configured to set a voltage of a first output terminal (Tout1) to one of a first voltage and a second voltage, based on an output signal of the first selector in the first operation mode; and a second driver configured to set a voltage of a second output terminal (Tout2) to one of the first voltage and the second voltage, based on an output signal of the second selector in the first operation mode; and a third driver configured to set a voltage of a third output terminal (Tout3) to one of the first voltage, the second voltage, and a third voltage, based on a third signal in the second operation mode, wherein in the second operation mode, the first driver, the second driver and the third driver set the first, second and third voltage such that they are different from each other, thereby constituting a three-phase signal. a controller configured to select one of a first operation mode, a second operation mode and a third operation mode, wherein in the first operation mode data are transmitted by means of a differential signal, in the second operation mode data are transmitted by means of a three phase signal and in the third operation mode data are trasnmitted by means of a single-phase signal; a first selector configured to, in the first operation mode, alternately select one of a first signal and a second signal, and output the selected one of the first signal and the second signal; a second selector configured to, in the first operation mode, alternately select one of an inversion signal of the first signal, when the first selector selects the first signal, and an inversion signal of the second signal, when the first selector selects the second signal, and output the selected one of the inversion signal of the first signal and the inversion signal of the second signal; a first driver configured to set a voltage of a first output terminal (Tout1) to one of a first voltage and a second voltage, based on an output signal of the first selector in the first operation mode; and a second driver configured to set a voltage of a second output terminal (Tout2) to one of the first voltage and the second voltage, based on an output signal of the second selector in the first operation mode; and a third driver configured to set a voltage of a third output terminal (Tout3) to one of the first voltage, the second voltage, and a third voltage, based on a third signal in the second operation mode, wherein in the second operation mode, the first driver, the second driver and the third driver set the first, second and third voltage such that they are different from each other, thereby constituting a three-phase signal.