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.

Date of Patent:
Mar. 26, 1996

Filed:

Oct. 31, 1994
Applicant:
Inventor:

Koichi Sawahata, Tokyo, JP;

Assignee:

NEC Corporation, Tokyo, JP;

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G02B / ;
U.S. Cl.
CPC ...
364525 ; 382280 ;
Abstract

A novel method for analyzing a light intensity distribution on a flat surface in a projection system wherein a pattern is projected by use of a light through a pupil on the flat surface. The pattern is analyzed into plural polygonal elements where a combination of the polygonal elements constitutes the pattern. Fourier transformations of vertexes of each of the polygonal elements except for the pattern are calculated for subsequent addition and subtraction of the Fourier transformations of all the polygonal elements to thereby obtain a Fourier transformation of the pattern. A product of the Fourier transformation of the pattern and a pupil function is calculated for the pupil. An invert Fourier transformation of the product is calculated to thereby obtain a light intensity distribution.


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