摘要 |
A coordinate reader comprises a coordinate detector body having at least one excitation line, at least one detection line, an exciting circuit connected to the excitation line for supplying an exciting signal, a signal processing circuit connected to the detection line for receiving an induction signal generated in the detection line and outputting a signal containing amplitude information of the induction signal, and a control circuit for receiving the signal outputted by the signal processing unit and outputting an excitation control signal to the exciting circuit. A coordinate indicator indicates position information obtained from the induction signal induced in the detection line. A phase detecting circuit detects a phase difference between the excitation signal and the induction signal generated in the detection line. By this structure, an induction signal component due to the direct electromagnetic coupling between the excitation line and the detection line is eliminated, the required accuracy in calculation of the coordinates is ensured, and the read invalid region can be further reduced.
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