| US 7,567,344 B2 | ||
| Apparatus and method for characterizing defects in a transparent substrate | ||
| Philip Robert LeBlanc, Corning, N.Y. (US); Vitor Marino Schneider, Painted Post, N.Y. (US); and Correy Robert Ustanik, Painted Post, N.Y. (US) | ||
| Assigned to Corning Incorporated, Corning, N.Y. (US) | ||
| Filed on Mar. 28, 2007, as Appl. No. 11/729,299. | ||
| Claims priority of provisional application 60/799899, filed on May 12, 2006. | ||
| Prior Publication US 2007/0263206 A1, Nov. 15, 2007 | ||
| Int. Cl. G01N 21/00 (2006.01) | ||
| U.S. Cl. 356—239.1 [356/237.2; 356/239.8; 430/5; 430/30; 430/311] | 16 Claims |
| 1. A method for detecting defects in a transparent substrate comprising:
providing a transparent substrate comprising a front surface and a back surface;
illuminating an interior portion of the transparent substrate with at least one light source arranged to provide dark field
illumination of the interior portion relative to a scanning imaging system;
illuminating the transparent substrate interior portion with at least one light source arranged to provide bright field illumination
of the interior portion relative to the scanning imaging system, wherein light comprising the bright field illumination enters
the interior portion through the transparent substrate front surface and is reflected from the transparent substrate back
surface within the interior portion of the transparent substrate;
translating the transparent substrate relative to the scanning imaging system; and
simultaneously detecting the light from the at least one bright field light source reflected from the back surface of the
transparent substrate and light scattered by a defect within the interior portion illuminated by the dark field illumination
by scanning the transparent substrate with the scanning imaging system while the transparent substrate is translated.
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