Design and construction of linear laser encoders that possess high tolerance of mechanical runout.
A linearly diffracted laser encoder that has high tolerance of head-to-scale misalignment and a high signal-to-noise ratio is described. The preservation of parallelism between the incident and the diffracted beams, which can be attributed to a built-in folded 1x telescope, allows for the high alignment tolerance. It can be shown that, by coupling this newly developed circular polarization interferometer configuration with grating scale geometry optimization, one can eliminate the problems associated with signal distortion that arise from various efficiencies of the p- and the s-polarized light beams and obtain a high signal-to-noise ratio. Both theoretical and experimental results are presented to confirm the improved results and performance.
Lee
Chih-Kung
CK
Institute of Applied Mechanics, National Taiwan University, Taipei 106, Taiwan. cklee@mems.iam.ntu.edu.tw
Wu
Chyan-Chyi
CC
Chen
Shih-Jui
SJ
Yu
Liang-Bin
LB
Chang
You-Chia
YC
Wang
Yeong-Feng
YF
Chen
Jau-Yu
JY
Wu
Jeremy Wen-jong
JW