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. 26, 1988
Filed:
Oct. 28, 1985
Applicant:
Inventors:
Assignee:
Hitachi, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G01N / ;
U.S. Cl.
CPC ...
356237 ; 250572 ; 358199 ;
Abstract
The present invention provides a method for detecting foreign substances which detects a foreign substance with a first photoelectric conversion element by emphasizing the foreign substance and detects a background on the object with a second photoelectric conversion element by emphasizing the background and detects a foreign substance detection signal obtained from the first photoelectric conversion element by emphasizing the signal with a detection signal obtained from the second photoelectric conversion element.