Angular position encoder - has encoding plate with incremental markings, and combines coarse and fine angle signals to produce absolute angle signal

摘要

The angle encoder contains an encoding plate with two tracks, each with incremental markings and detected by a sensing head. A fine angle value is produced (84,94) by interpolation between the incremental markings. Both tracks have different scales and absolute coarse angle values are formed (88,90,92) from the phase difference between the signals produced by the sensing heads from the divisions on the two tracks. The coarse and fine values are superimposed (96) to form a high resolution, absolute angle signal. ADVANTAGE - Combines simple construction of incremental angle encoder with advantages of absolute angle measurement.