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:
Apr. 04, 2006
Filed:
Aug. 12, 2002
Yasushi Sasa, Kyoto, JP;
Yasushi Sasa, Kyoto, JP;
Dainippon Screen Mfg. Co., Ltd., Kyoto, JP;
Abstract
A marginal distribution feature extraction unitsequentially focuses on each pixel in a reference image and the corresponding pixel in an inspection image, and computes a marginal distribution feature value indicative of the spatial variation in pixel values in the focus pixel neighborhood in both images. Based on this marginal distribution feature value, a tolerance image generation selection unitsets a tolerance range for the reference image or inspection image focus pixel with the less spatial variation. A target image selection unitselects the image comprising pixels from both images for which a tolerance range is not set as a target image. Referencing the set tolerance ranges, a comparison operatorcompares each pixel in the target image and tolerance image, and outputs a difference Sub representing how far the pixel values of the target image are from the respective tolerance range. A defect determination circuitthen outputs data indicating the pixels corresponding to a defect based on a difference map containing these difference Sub values.