Technique for determining defect positions in three dimensions i

Details Technique for determining defect positions in three dimensions i Technique for determining defect positions in three dimensions i

1996-09-26

1998-08-04

Pham, Hoa Q.

Optics: measuring and testing

Inspection of flaws or impurities

Having predetermined light transmission regions

356239, G01N 2117

Patent

active

057902470

ABSTRACT:
A method (500) for inspecting anomalies, which are likely defects of several types, namely, particles on the surface, scratches into surface, and defects in bulk material, is provided. This inspection method involves two types of illumination, which can be used separately or together. These two types highlight anomalies sufficiently differently to enable the defect monitoring tool to distinguish between defect type and defect location along an inspection axis. The illumination methods are direct internal side illumination (114) where the plate is used as light pipe, and external front-side illumination (117). In direct internal side illumination, a fiber optic feed (115) with flared end arranged as a line source is abutted to an edge (123) of the plate (102). In external side illumination, the source is light directed at an acute angle, preferably a grazing angle, to one of the surfaces (121). Anomalies such as dust particles on the illuminated surface will scatter light much more efficiently with external front-side illumination, than direct internal side lighting, since particles on the surface would otherwise scatter light only through weak evanescent coupling via the internal side lighting.

REFERENCES:
patent: 4808813 (1989-02-01), Champetier
patent: 5177559 (1993-01-01), Batchelder et al.
patent: 5268735 (1993-12-01), Hayshi
patent: 5355213 (1994-10-01), Dotan
patent: 5515159 (1996-05-01), Sites et al.
patent: 5631733 (1997-05-01), Henley

Affiliated with

Also associated with

Rating

Technique for determining defect positions in three dimensions i does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Technique for determining defect positions in three dimensions i, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Technique for determining defect positions in three dimensions i will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-1183567