Patent ID: 7292332

Claim:
A method for detecting faults in a transparent manufactured material in order to ascertain whether or not the transparent manufactured material meets predetermined specifications during quality control testing, said method comprising the steps of: a) irradiating a definite partial volume entirely within an interior of the transparent manufactured material with a first radiation source; b) coupling light of a second radiation source into the transparent manufactured material so that an optical path of said light passes through said definite partial volume entirely within said interior of the transparent manufactured material; c) detecting scattered light from said fault in said partial volume, detecting bright field absorption from said fault in said partial volume and/or detecting deflection of light of said first radiation source by said fault in said partial volume in order to detect the presence of said fault in said partial volume of the transparent manufactured material; and d) determining a fault type of said fault from a ratio of a bright field signal to a scattered light signal or from a ratio of a deflection signal to said scattered light signal; and e) producing an output signal characterizing the fault type of said fault detected within said definite partial volume according to said ratio.