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. 17, 1998
Filed:
Feb. 01, 1996
Fuminori Hayano, Tokyo, JP;
Nikon Corporation, Tokyo, JP;
Abstract
A particle inspecting apparatus capable of detecting only particles without depending on conditions such as a density, a configuration, etc. of an original pattern of an object to be inspected is provided. The apparatus includes a light irradiating device for irradiating the inspected object with a beam of light and a condensing optical system for condensing the beam from the inspected object. The apparatus also includes a light limiting device, disposed in the vicinity of a Fourier transform plane for the inspected object in the condensing optical system, for admitting a passage of the beam corresponding to only a part of a Fourier transform pattern of the beam from the inspected object, a relative position shiftable device for shifting relative positions of the Fourier transform pattern of the beam from the inspected object and the light limiting device and a detecting device for detecting the particle on the basis of the beam passing through the light limiting device.