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:
Oct. 29, 2002
Filed:
Jun. 23, 2000
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
A light device includes a shielding plate ( ) having an opening ( H) of a rectangular cross-sectional configuration and placed over an optical window retainer ( ). The shielding plate ( ) is placed so that an opening wall surface ( HS) thereof is positioned on an optical path (Zr(x)) of light emerging from an optical window ( ) at a usable angle (&thgr;e) and that a half width (Xu) of the opening ( H) satisfies Xu=u/cot(&thgr;e)+t×sin(&thgr;e)/sgrt(n −sin (&thgr;e))+s. The optical window retainer ( ) is placed in a region outside a boundary line given as Zh(x)=±(1×tan(&thgr;e)(x±Xu)+u (plus (+) when x≦−Xu; minus (−) when x≧Xu) and also in aregion outside the optical path (Zr(x)). The light source device suppresses an uneven illuminance distribution of exposure light resulting from superimposition of light scattered from the opening wall surface of the optical window retainer upon the exposure light.