Analysis of Signal Distortion Caused by Opening Ratio Variation of Main Scale and Index Scale in Linear Encoder

Abstract

Linear encoder as an important displacement measurement device has been widely used in manufacturing industry. The accuracy of linear encoder is based on the precision of its scales. In this article, the manufacturing process of the scales based on photolithography process and etching process was discussed in order to explain the opening ratio variation. A mathematical model was derived to analyze the effects of opening ratio variation on the waveform of output signal. The result shows that the waveform of the signal is cut off in comparison with the ideal waveform, and the magnitude of the output signal is changed.