摘要:
A coordinate inputting apparatus has a separating circuit, a cable and a position indicating pen. The separating circuit has a low pass filter for removing an alternating current component from a signal transmitted to a signal line and a band pass filter for passing only a position information signal in a predetermined frequency band with respect to the signal transmitted to the signal line. The cable is constructed by a signal line, a switching signal line and a ground line. The signal line is used to supply power to the position indicating pen and transmit a detecting signal from the position indicating pen to each of an X-coordinate detecting circuit and a Y-coordinate detecting circuit. The position indicating pen has a low pass filter for removing an alternating current component from a signal transmitted through the signal line and a band pass filter for passing only a position information signal in a predetermined frequency band. A signal transmitting system of this coordinate inputting apparatus and other coordinate inputting apparatuses are also shown.