Patent Document ID: 20050220335
Application ID: 11095960
Patent Status: 0

Claim One:
1. A method and apparatus for substantially complete measurement and determination of surface imperfections and porosity, within a predetermined size range, contained in one or more inspection zones therefor, said method comprising the steps of: a) positioning the sample in the inspection chamber whereby the sample is located precisely using a mechanical means that will allow the entire surface to be inspected to be observed without obstruction; b) illuminating uniformly all of the surfaces to be inspected with lighting means; c) apply a vision algorithm or algorithms to accurately locate the reference features on the sample surface and to electronically reposition the acquired image to coincide with a preset Reference position; d) illuminating the background (machined surfaces) so that all imperfections within the inspection zone or zones contrast with the background; e) detecting at least one of light scatter, light reflection and light extinction caused by said imperfection, with detector means having a depth of focus; f) image processing system extracts relevant imperfections using one or more inspection algorithms to produce equivalent sizes in pixels or the summation of grayscale values of selected pixels; g) the applications of one or more inspection zones in which specific inspection criteria may be applied to the relevant imperfections; and h) one or more numerical calculations are performed to correlate the size of the imperfection in pixels to equivalent physical dimension in micrometers using calibration curve established by measuring a NIST traceable standard or other standard; characterized in that the photo detector(s) are positioned relative to the sample, whereby a focal point of detection coincides with the surface of the sample, whereby the center of the detector is position to coincide with the center of the sample so to view substantially all of the samples surface, whereby the detected imperfections are on the surface of the sample; wherein said lighting means provides a contrasting geometric size and shape of substantially all of the imperfections of the sample.