Abstract: The present invention transmits, to an electronic board controller 14, click signals generated upon manipulating multiple switches provided on a coordinates-inputting pen 13, timing signals upon detecting infrared scanning beams 18a and 18b, and the like without using a connecting wire. Specifically, light-emitting elements are provided which can emit visible or infrared light to the coordinates-inputting pen 13. A timing signal upon detecting the infrared scanning beam with the pen and a click signal generated upon manipulating the switch on the pen are sent out on a modulated light 19 to be received by a light receiver 20 arranged at a fixed position and transmitted to the electronic board controller 14.