The absolute encoder has such advantages as fixed starting-point

reliable reading

and so on. But traditional absolute encoder is limited in use

because of its large number of rings and large size. So micro encoder is desired. This paper introduces design procedures about a micro absolute matrix encoder

including the design of absolute matrix code disk

working principle

procedure of matrix decode. The minimum radial size of traditional absolute encoder of 14 bits is φ130mm. While using matrix code disk

the radial size of same bit encoder can be reduced to φ65mm.