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:
Jan. 03, 1995
Filed:
Dec. 30, 1993
Applicant:
Inventors:
Yoko Miyazaki, Hyogo, JP;
Toshimasa Tomoda, Hyogo, JP;
Hitoshi Tanaka, Hyogo, JP;
Nobuyuki Kosaka, Hyogo, JP;
Toyomi Ohshige, Hyogo, JP;
Assignee:
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G02B / ; G01B / ;
U.S. Cl.
CPC ...
359561 ; 359559 ; 430-5 ; 430 15 ; 356237 ;
Abstract
A spatial frequency filter used in a pattern defect detection device, including a pattern which includes a black spot having a diameter expanded by a controlled amount in comparison with the diameter of a black spot on a photosensitive plate obtained by exposure by diffracted light from a pattern on a model specimen.