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. 25, 1999
Filed:
Aug. 01, 1997
Naohiko Fujino, Tokyo, JP;
Junji Kobayashi, Tokyo, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
In a particle detecting method, a light beam is projected on a surface of a workpiece. By a microscope focused on a spot of the light beam, formed is an image of irregularly reflected light irregularly reflected by a minute dust particle lying on the surface of the workpiece. The image of the irregularly reflected light is taken by an image pickup tube disposed at a position corresponding to the eyepiece unit of the microscope. The image of the irregularly reflected light is displayed on a screen of a display tube. The image is analyzed by a computer to determine the position of the minute dust particle on the workpiece in an X-Y plane. Further, the workpiece or the microscope is moved in an X-Y plane to inspect the entire surface of the workpiece.