| 摘要 |
<p>PURPOSE:To omit a wire connecting an indicating device and a coordinate detecting device main body by restoring the energizing signal of the indicating device by means of the signals produced by two lead wires which are set on a tablet with a shift secured between both phases. CONSTITUTION:An energizing coil 4 of an indicating device 15 is energized by the energizing signal of a sine wave. The signals of two lead wires provided on a tablet 5 with a shift secured between both phases are supplied via a switch 6 and amplified by amplifiers 7 and 8. These amplified signals are added together by an adder 18 after undergoing the full-wave rectification through absolute value circuits 16 and 17. The output signal of the adder 18 is supplied to a comparator 19 and converted into two continuous pulses. These pulses are divided into 1/2 by a divider 20. Thus the pulses outputted from the divider 20 have the same phase and the same cycle as the pulse of the energizing signal of a device 15. This pulse signal is supplied to a phase comparator 12. As a result, the coordinate detection is possible without outputting the energizing signal to the comparator 12 from the device via a wire. Thus the device 15 is easily handled.</p> |
