Retroreflective moiré deflectometry: phase and specular object inspection

Evangelos Liasi; Walter P. T. North

doi:10.1117/12.163206

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1 April 1994 Retroreflective moiré deflectometry: phase and specular object inspection

Evangelos Liasi, Walter P. T. North

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Optical Engineering, 33(4), (1994). https://doi.org/10.1117/12.163206

Abstract

The use of moiré deflectometry for quality control applications is investigated. Moiré deflectometers were designed and used in the experiments, most importantly the retroreflected moiré deflectometer. Two parts were addressed: phase object analysis and specular object analysis. First, a density variation in a piece of glass (phase object) was examined. Moiré deflectograms were obtained using a conventional moiré deflectometer coupled with a retroreflector and a retroreflective deflectometer with a white light source. Ray deflection versus position graphs as well as 3-D ray deflection maps were generated. Second, both a large and a small outdent on a specular surface were investigated. The attempt to replace the laser with the white light source in a traditional moiré deflectometer did not yield any useful results. Moiré deflectograms were, however, obtained with the use of the traditional moiré deflectometer and with the arrangement employing a retroreflector. Slope versus position graphs were generated and compared to a calibrated artifact. The comparisons were very poor. Despite these results, moiré deflectometry can be used to locate such flaws.

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Evangelos Liasi and Walter P. T. North "Retroreflective moiré deflectometry: phase and specular object inspection," Optical Engineering 33(4), (1 April 1994). https://doi.org/10.1117/12.163206

Published: 1 April 1994

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