| 摘要 |
<p>PURPOSE:To improve the operability and S/N of an information input device by transmitting a signal radio wave via a pointing device having a contact at a desired position of a tablet, receiving the signal radio wave via an electrode wire set in the tablet, and specifying the detecting position of the received signal. CONSTITUTION:When a signal transmission pen 8 is applied to a desired position of a tablet 2, a carrier signal C is induced on an electrode wire set close to the contact position of the pen 8. The signal C is amplified by an amplifier 12 via a reception electrode with switch 11, and only a carrier signal of a prescribed frequency is taken out via a filter 13. This signal is demodulated by a detection circuit 14, and the signal detected via each electrode wire is turned into a DC signal F corresponding to the position information. The signal F is applied to a control circuit 20 via an A/D converter 15. Then the signal F is processed by the circuit 20 as the position information and sent to a computer. Thus the operability and the S/N are improved for an information input device.</p> |
