| 摘要 |
<p>PURPOSE:To set a level accurately and easily by inputting a signal with a linear waveform to a level discriminating circuit which has discrimination levels dividing equally the unit scale of the extent of parallel or rotary movement of the drawing head of a rail type drawing instrument. CONSTITUTION:For digital display by detecting the turning angle of a head, an optical black and white grating is formed on a circular record disk and codes of it are detected by an optical angle detector. In a linear waveform generating circuit in an angle display circuit, signals A and B from the 1st and 2nd angle detectors are inputted to phase inverting circuits 35 and 43 and while an output D of f2(theta) =1+costheta is obtained from the output terminal 41 of the circuit 35, a waveform E of f1(theta)=1+sintheta is outputted from the output B of a circuit 51 by a full-wave rectifying circuit 85. To independent channel terminals 109 and 110 of a multiplexer 68, signals J and K from phase inverting circuits 103 and 107 are supplied, and the multiplexer 68 generates and input a signal L by the input signals to an adding circuit 86, which outputs a signal with an approximately linear waveform shown by the equation.</p> |
