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:
Dec. 01, 1992
Filed:
Apr. 06, 1992
Applicant:
Inventors:
Assignee:
Asahi Kogaku Kogyo Kabushiki Kaisha, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G03B / ;
U.S. Cl.
CPC ...
355 53 ; 355 41 ;
Abstract
An exposure apparatus where a mask table having an exposing pattern and a work to be exposed are relative to each other movable, wherein the moving amount of the mask table is detected by a scale image formed through a projection lens system, so that even if the projection lens system has a magnification error, by optically offsetting it, the moving amount of the mask table can be detected. Thus, a more accurate control can be obtained so that a mask image can be more precisely reproduced on a work.