| 摘要 |
<p>PURPOSE:To eliminate a derived component superimposed on a signal by providing an integration circuit which adds a reception signal on a processing circuit to process the signal of a position sensor substrate for plural times. CONSTITUTION:A reception circuit 7 selects the resonance electromagnetic wave of an indicator 8 which resonates with an electromagnetic wave radiated from the loop coil 51 of an oscillator 63, and judges that the maximum reception value should be taken when which loop coil 51 is selected, and also, the amount of deflection is found from the output value of a neighboring loop coil 51 at that time. The integration means of a waveform processing circuit 72 in the reception circuit 7 is to perform the delay by one cycle of a burst signal, and the reception signals for the same loop with different number of times appear at an input part and an output part on an analog delay line by supplying the burst signal to the same loop for plural times. An original signal can be doubled by adding such signal by an analog adder, and a noise component appears at random, which results mutual negation. Therefore, noise elimination synchronized with the burst signal can be performed.</p> |
