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:
May. 05, 1998
Filed:
Jun. 28, 1996
Ken Shimono, Hirakata, JP;
Tatsuo Nagasaki, Hirakata, JP;
Kenji Takamoto, Neyagawa, JP;
Masami Ito, Moriguchi, JP;
Kanji Nishii, Osaka, JP;
Matsushita Electric Industrial Co., Ltd., Osaka-fu, JP;
Abstract
A method for foreign particles inspection includes illuminating an inspection surface of an inspection object with a beam which is, one of s-polarized and p-polarized relative to the inspection surface of the inspection object. The illumination utilizes an optical axis which is generally parallel to the inspection surface or which intersects the inspection surface at an angle that is greater than or equal to 1.degree. and less than 5.degree.. Reflected and scattered light is detected utilizing an optical axis which makes an acute angle with the inspection surface and which makes a differential angle of 30.degree. or less with the optical axis of the illumination beam. The detection of foreign particles is accomplished by detecting the component of the reflected and scattered light which is the other of s-polarized and p-polarized relative to the inspection surface.