TELEPHONE SET WITH INFRARED-RAY COMMUNICATION FUNCTION

PROBLEM TO BE SOLVED: To reduce the power consumption in an infrared-ray communication equipment. SOLUTION: Half-duplex infrared-ray communication is conducted between a portable telephone set main body section 12 and a transmission reception section 13. A primary station starting communication at first stops power supply to the infrared-ray communication equipment from the point of time when the reception of a reception (reply) signal from a secondary station is finished till a point of time when the transmission of a voice or control signal is started next. When the transmission interval and timing of the primary station are constant, the secondary station stops power supply to the infrared-ray communication equipment at the end of transmission of the reply signal, and releases the stop of power supply at a predicted time when the primary station transmits signals.