The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 03, 2013
Filed:
May. 22, 2009
Kazufumi Sakai, Saga, JP;
Kazuhiro Nonaka, Saga, JP;
Kazufumi Sakai, Saga, JP;
Kazuhiro Nonaka, Saga, JP;
Abstract
Light from a light source device () is polarized through a polarizer () and is caused to impinge obliquely on an object (W) to be inspected. The resulting scattered light (SB) is received by a CCD imaging device () having an element () for separating scattered light disposed in a dark field. Component light intensities are worked out for an obtained P-polarized component image and an obtained S-polarized component image and a polarization direction is determined as a ratio of them. The component light intensities and the polarization directions are determined from images obtained by imaging of the light scattering entities in a state where stress is applied to the object to be inspected and in a state where stress is not applied thereto. The component light intensities and the polarization directions are compared with predetermined threshold values. As a result, defects in the inspection object, such as internal deposits or cavity defects, foreign matter or scratches on the surface or cracks in the surface layer can be detected with high precision and the defects can be classified by identifying the type of the defect.