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:
Sep. 14, 2004
Filed:
Jun. 13, 2002
Yasuhiro Gotoh, Kadoma, JP;
Seiji Nishiwaki, Kobe, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
An apparatus for determining an existence range of a foreign substance which is present on a surface of an object, includes: an optical system including a light source for emitting a light beam on to the surface of the object; a movement section for relatively moving the object with respect to the light beam; a light detection section for detecting a light quantity of the light beam reflected by the surface of the object to generate a light detection signal which indicates the light quantity; a difference signal generation section for generating a difference signal; a perimeter signal generation section for comparing the difference signal with a reference value to generate a perimeter signal; and a foreign substance determination section for determining an existence range of the foreign substance using the perimeter signal.