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:
Jul. 10, 2001
Filed:
Oct. 28, 1999
Tomohiro Miyashita, Kiyose, JP;
Yutaka Suenaga, Yokohama, JP;
Nikon Corporation, Tokyo, JP;
Abstract
Disclosed is a dark field illumination apparatus which is capable of performing a dark field illumination which exhibits a sufficient brightness and a sufficiently suppressed unevenness in brightness. The apparatus comprises a shaping system for shaping a light beam from a light source into approximately parallel beam having a ring- shaped section; a fly-eye optical device for forming a plurality of light source images in the vicinity of its exit plane based on the approximately parallel beam, the light source images being arranged circularly; and a light collection optical system for collecting light beams from the light source images and superposing them on an object plane.