| 摘要 |
<p>PURPOSE:To simplify a manufacturing process and to enable a stable operation for a long time by simplifying a circuit and making a coordinate indicator non-adjustable. CONSTITUTION:A coordinate indicator 8 is equipped with a resonance circuit. A first sense line group S1 and a second sense line group S2 are provided so as not to be directly electromagnetically connected. First and second scanning circuits 1 and 2 successively select the sense line groups. At that time, a coordinate detecting circuit 5 applies an amplitude switching signal 103 to an AGC circuit 13, and the amplitude of an amplifier 3 is set as a constant value. When a coordinate indicator 8 approaches the sense line groups, a positive feedback loop circuit is constituted of those sense line groups and the amplifying circuit 3, and an oscillation signal 101 is generated. The oscillation signal is connected through the resonance circuit with the second sense line group S2, the amplitude of an input signal 102 has the instructed position information of the coordinate indicator 8, and a coordinate detecting circuit 5 inputs it, and calculates an instructed position.</p> |
