| 摘要 |
<p>PURPOSE:To improve the detecting performance for coordinate position by detecting the differences among the reference signal, the 2nd signal having a prescribed difference of phase from said reference signal and the input pen detection signal and detecting the position of an input pen from said differences. CONSTITUTION:A coordinate position detector contains opposite electrodes D1 and D2 of a plane resistor 1, electrode changeover switches S1 and S2 connected to the electrodes D1 and D2, etc. and then detects the coordinate position of an input pen 2. In this case, two reference signals e1 and e2 which are different from each other in terms of the phase only are applied to the electrodes D1 and D2 after closing the switches S1 and S2. The signal e1 and the detection signal of the pen 2 are converted into the clock signals given from a reference oscillator 7 by a gate circuit 61 via comparators 31 and 4 and an RS flip-flop 51 and then counted in the positive direction by a reversible counter 10. While the signal e2 is also processed in the same way and counted in the negative position by the counter 10. Then the coordinate position is delivered from a conversion ROM9 by the difference of count numbers of both signals.</p> |
