Impact Statement:We report the procedure of using dot-matrix gratings based disc and a beam-shaping lens to design a digital rotary encoder. Compared with a conventional geometric one, th...Show More
Abstract:
In this paper, a high-precision digital rotary encoder based on dot-matrix gratings (DMGs) is proposed for detecting shaft rotation. The DMG-based encoder is composed of ...Show MoreMetadata
Impact Statement:
We report the procedure of using dot-matrix gratings based disc and a beam-shaping lens to design a digital rotary encoder. Compared with a conventional geometric one, the proposed diffractive encoder improves the angular resolution fourfold. The prototype is composed of 16,384 stripes of dot matrix-gratings to provide a detection resolution of 0.022°. Each stripe is further composed of seven DMG for absolute encoding and two DMG for subdivision encoding.
Abstract:
In this paper, a high-precision digital rotary encoder based on dot-matrix gratings (DMGs) is proposed for detecting shaft rotation. The DMG-based encoder is composed of a laser diode, a beam-shaping lens, a code disc, and a detector. In principle, a shaped rectangular beam illuminates a stripe of DMGs on the disc, and from the distribution of diffractive spots on the detector, the position of rotation is then decoded. Compared with a conventional geometric rotary encoder, this diffractive rotary encoder can achieve a fourfold resolution improvement.
Published in: IEEE Photonics Journal ( Volume: 10, Issue: 2, April 2018)