92 A New Illumination System for Defect Inspection on Highly Specular Surface Available to Purchase

This paper presented a new illumination system for defect inspection on the highly specular surface, especially for Chrome-plated surface. The surface is perfect specular, from which the diffuse reflection components are weak while specular reflection components are so strong that its intensity saturate the CCD matrix to causes some surface features to be lost. The square LED with white light pass through frosted glass and provides diffuse light source and a separate constant current source with intensity control were adopted. Diffuse illumination source with an optimum location impinge the specular surface also can reduce specular reflection from the surface and enhance the edge bright. But, variety of defects with different geometry shape maybe illuminated to perform specular reflection or covered by bright region in one image. So, a set of images are captured under the proposed illumination system. It is favorable for inspecting objects with highly reflective or uneven surfaces. By using of the system, some experiments defect inspection on chrome-plated surface show that the system is efficient and feasible.