The systems presented in this paper are based on phase-shift measurement. The first solution developed here is the heterodyne technique associated with direct counting. An improvement of the system consists in using digital PLL to reduce the phase noise. A second technique based on under-sampling technique, applied to digital synchronous detection, is described. Its main advantage is a global simplification of the electronic system, leading to a quite simple development of a twofold modulation system. This new technique is also very interesting to move towards a kind of smart range finder able to adapt different parameters to the different steps of the measurement.

Date Published: 12 February 2001
PDF: 9 pages
Proc. SPIE 4189, Machine Vision and Three-Dimensional Imaging Systems for Inspection and Metrology, (12 February 2001); doi: 10.1117/12.417192

Published in SPIE Proceedings Vol. 4189:
Machine Vision and Three-Dimensional Imaging Systems for Inspection and Metrology
Kevin G. Harding; John W. V. Miller; Bruce G. Batchelor, Editor(s)