| 摘要 |
<p>PURPOSE:To realize a coordinate reader getting a coordinate value without scanning, to simplify the structure of a tablet and to accelerate coordinate calculation. CONSTITUTION:A coil 13 is built in a coordinate indicator 12, and an AC magnetic field is generated by an exciting signal from an excitating circuit 11. Detection lines with unequal width and winding detection lines are spread on a tablet 1, and a guiding signal with an amplitude corresponding to the position of the coil 13 is induced. A switching circuit 7 successively guides these guide signals to a signal processing circuit 8. The signal processing circuit 8 generates the envelop signals of the guiding signals. A calculation circuit 9 calculates a rough position according to the envelop signals in the detection lines with the unequal width, calculates a precise position according to the envelop signals in the winding detection lines and calculates a coordinate value from both positions.</p> |
