An objective of one embodiment of the present invention is to reduce abrupt noise derived from infrared light emitted by a light source from a data signal of infrared light received by an infrared communications receiver for use with a display device including a light source without reducing the strength of the data signal. A multiplication factor for the amplitude of abrupt noise outputted by a lamp light-receiving element disposed in the vicinity of lamps of a liquid crystal television is adjusted in order for the amplitude of abrupt noise derived from the lamps and outputted by the lamp light-receiving element to be equalized with the amplitude of abrupt noise derived from the lamps and included in a data signal outputted by a data light-receiving element. Then, the abrupt noise subjected to multiplication factor adjustment is subtracted from the data signal including the abrupt noise, so that only the data signal remains and is transmitted to the liquid crystal television.