PROJECTION MOIRÉ PROFILOMETRY USING LIQUID CRYSTAL DIGITAL GRATINGS

Fumio Kobayashi, Yukitoshi Otani, Toru Yoshizawa
Abstract:
A projection moiré profilometry using a pair of liquid crystal digital gratings (LCDG) is applied to determine a step height using two liquid crystal digital gratings (LCDGs). Moiré contours are filtered over to remove the images of the original grating from the moiré counter when a pairs of grating images are traveled to the same direction in-phase electrically. The new idea of this report is proposed to overcome the 2 π ambiguity of moiré contour by changing the fringe interval of Moiré contours which are adjusted the period of LCDGs. The measured accuracy has been achieved to ±0.7 mm in the range of 96 mm of steep height by projecting two different of grating periods as 6.7 and 13.3 time of original grating.
Download:
IMEKO-TC14-2011-25.pdf
DOI:
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Event details
IMEKO TC:
TC14
Event name:
TC14 LMPMI Symposium 2011
Title:

10th Symposium on Laser Metrology for Precision Measurement and Inspection in Industry

Place:
Braunschweig, GERMANY
Time:
12 September 2011 - 14 September 2011