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:
Aug. 26, 1997
Filed:
Apr. 09, 1996
Noriaki Yamamoto, Kitakatsushika-gun, JP;
Tetsuo Kikuchi, Tokyo, JP;
Nikon Corporation, , JP;
Abstract
An illumination optical apparatus of this invention is small in size as a whole and capable of illuminating a plurality of illumination areas on a mask. The illumination optical apparatus illuminates a plurality of areas on a mask to be projected/exposed. This apparatus includes at least two light sources, a focusing optical system for focusing light beams from the respective light sources to form light source images, a light guide having incident ends equal in number to the light sources and exit ends equal in number to the illumination areas and serving to guide light beams from the respective light source images incident on the incident ends to the exit ends, and an illumination optical system for irradiating the light beams from the respective light source images emerging from the exit ends of the light guide onto the corresponding areas on the mask. The light guide is constituted by a plurality of optical fibers bundled together and divides light beams to make the amounts of light beams at the respective exit ends almost equal to each other.