| 摘要 |
<p>PURPOSE:To eliminate necessity of leading a reference signal from the same signal source with an exciting signal and make it possible to make a coordinate indicator wireless by providing a reference signal generating device that generates a reference signal identical with an exciting signal in a signal processing circuit. CONSTITUTION:A calling-on signal (e) induced by an exciting signal is inputted successively to the phase detector 12 and a calling-on signal detector 15 of a signal processing circuit. The signal inputted to the detector 15 is detected as a receiving wave detection signal (k), and converted to a gate signal (g) by an FF 16. On the other hand, a signal of 2<n> times exciting signal is outputted from a reference signal oscillator 17, and inputted to a counter 19 through a gate 18 opened by the gate signal (g). The counter 19 frequency divides the signal into (n) parts and outputs to a phase detector 12 as a reference signal (s). Accordingly, the reference signal (s) has similar phase relation to the calling-on signal, and therefore, the calling-on signal (e) can be converted to the phase detection signal (g) by the signal (s).</p> |
