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:
Feb. 10, 1998
Filed:
Apr. 24, 1996
Masami Ito, Osaka, JP;
Kenji Takamoto, Osaka, JP;
Kanji Nishii, Osaka, JP;
Tatsuo Nagasaki, Osaka, JP;
Ken Shimono, Osaka, JP;
Abstract
A foreign substance inspection apparatus having a good signal to noise ratio with optical detection accuracy capable of detecting infinitesimal foreign substances, comprising a lighting portion to irradiate with an S polarized laser light beam and having the optical axis parallel to the substrate to be inspected, a detecting portion having an optical axis located in a position set by rotating the optical axis of the lighting portion by 120.degree. to 160.degree. with the point of intersection of the optical axis of the lighting portion and the surface to be inspected as the center of rotation so as to have an angle made with the surface to be inspected of 45.degree. or smaller to detect the area irradiated from the lighting portion by detecting the S polarized component in the scattered component from the foreign substances existing on the surface to be inspected and converting the S polarized component photoelectrically to a signal, and a signal processing portion to detect a foreign substance based on the signal outputted from the detecting portion.