The back-lighted grid method for inspecting a reflective surface has been studied with analytical derivations and numerical modeling. The displacement of the image of a grid point due to surface waviness was found to be proportional to the surface slope along the viewing direction at the reflecting point and the distance between the grid and the reflecting point. The 2-D and 3-D numerical modeling was verified with analytical relations, and the 3-D modeling was then tested with the reflection from a profiled SMC (sheet molding compound) panel. The effects of short-term waviness, light box inclination, viewing angle, and surface waviness orientation are investigated. The reflection image patterns for typical surface features are predicted and characterized.

1.
Born, M., and Wolf, E., 1959, Principle of Optics, Pergamon Press, New York, p. 233.
2.
Kralovec, W. M., 1968, “Optical Evaluation of Long Term Surface Waviness,” 23rd Annual Conference, RP/C, SPI, Session 1-C.
3.
Lee
C.-C.
,
1999
a, “
Analysis and Modeling of Surface Waviness Inspection with Light Reflection, Part 1: Laser Beam Scanning Method
,”
ASME JOURNAL OF MANUFACTURING SCIENCE AND ENGINEERING
, Vol.
121
, pp.
778
784
.
4.
Lee
C.-C.
,
1999
c, “
Analysis and Modeling of Surface Waviness Inspection with Light Reflection, Part 3: Light Intensity Distribution Method
,”
ASME JOURNAL OF MANUFACTURING SCIENCE AND ENGINEERING
, Vol.
121
, pp.
793
801
.
5.
Reynolds, R. L., and Hageniers, O. L., 1988, “Optical Enhancement of Surface Contour Variations for Sheet Metal and Plastic Panel Inspection,” International Symposium on Optical Engineering and Industrial Sensing for Advanced Manufacturing Technologies, Dearborn, Michigan.
6.
Structural Dynamics Research Corporation (SDRC), 1988, I-DEAS Supertab Pre/Post Processing Engineering Analysis Version 4.0 User’s Guide.
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