| 摘要 |
PROBLEM TO BE SOLVED: To provide equipment for measuring a position which enables digital operation of a spatial waveform of an encoder electrode and attainment of a resolution of the spatial waveform smaller than an electrode pitch. SOLUTION: A transducer 110 receives a signal showing a composite spatial waveform on a transmission electrode 130 and outputs a signal showing relative positions of a slide 112 and a scale 114 to a reception electrode 160. The composite spatial waveform is generated by an exclusive-OR gate 462. In the gate 462, an output from an oscillator 450 is multiplied by a coefficient from ROM 470. A microprocessor 400 receives a signal Vf showing the amount of phase shift of spatial waveforms coupled through the transducer 110 and outputs an address to the ROM 470 so as to select a coefficient necessary for shifting the composite spatial waveform and making the signal Vf zero. A plurality of addresses are set so that the amount of phase shift of the composite spatial waveform be the average of the amounts of the phase shift of individual spatial waveforms corresponding to the individual addresses. |
