標題: High resolution planar encoder by retro-reflection
作者: Kao, CF
Lu, SH
Lu, MH
光電工程學系
Department of Photonics
公開日期: 1-Aug-2005
摘要: This investigation presents a planar diffractive laser encoder system (PDLENS), which serves as a two-dimensional (2D) position detection apparatus for precision machine applications. Traditional 2D position detection utilizes a pair of linear encoders in crossed construction and so maintaining the perpendicularity between this pair of encoders is difficult. Besides, the rigorous alignment requirements among various components of the encoder system impose a serious user adaptation bottleneck. Of all alignment tolerances, the head-to-scale alignment tolerance is the most important problem for applications. In this work, a 2D grating is employed as the scale and the PDLENS is based on the retro-reflection configuration. Therefore the new encoder can provide good perpendicularity and tolerate larger alignment errors than the conventional encoder does. The grating pitch is 1.6 mu m and the period of the output signal is 0.4 mu m due to the double diffraction. Electronic interpolation with a factor of 400 leads to a readout resolution of 1 nm. The new encoder and a capacitive sensor were employed to simultaneously measure a circular motion with a radius of 1 mu m generated by a piezo stage. Comparing the measured positions, the deviation is less than 30 nm and the repeatability is better than 8 nm. (c) 2005 American Institute of Physics.
URI: http://dx.doi.org/10.1063/1.2006368
http://hdl.handle.net/11536/13416
ISSN: 0034-6748
DOI: 10.1063/1.2006368
期刊: REVIEW OF SCIENTIFIC INSTRUMENTS
Volume: 76
Issue: 8
結束頁: 
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