Absolute Encoder

Abstract

We realized absolute encoder by a method to record the grating of the incremental encoder at plural gradation. In addition, by a method to remove the harmonic distortion of the projection pattern of coarse periodic grating, we balanced a high interpolation accuracy with installation easiness. In this report, we explain a principle, a constitution summary, development to the two-coordinate encoder, the measurement example of the interpolation precision and propose the applicable field.