| 摘要 |
<p>PURPOSE:To extend the coordinate read range without changing the frequency of an AC magnetic field generator, by arranging plural plane plates and by driving them in time division by the single AC magnetic field generator. CONSTITUTION:When a magnetic field detector 6 is placed on a plane plate 3, the detector 6 is coupled with the AC magnetic field in the position to generate an AC voltage or current. The output of the detector 6 is applied to a phase detector 7 and is compared with a reference phase signal from a terminal 9 to generate an output corresponding to the phase of the detection signal. A processing device 8 converts the output signal of the detector 7 to a signal corresponding to the use purpose of a coordinate reader and outputs the signal to an output terminal 10. Plane plates 1-3 are driven in time division by switching a switch 4. Coordinate positions of the whole of combined plane plates 1-3 are detected by switching timing information of the switch 4 and the phase from the phase detector 7.</p> |
