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. 06, 1992
Filed:
Apr. 15, 1991
Kazuhiro Takahashi, Kawasaki, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
A device for detecting the position of a light source of an illumination optical system. The position detecting system of the present invention is particularly suitable for use in the detection of any positional deviation, from a correct position, of a Hg lamp used in a semiconductor device manufacturing exposure apparatus. The device includes an optical system for forming a plane which is optically conjugate with the surface of an object to be illuminated and a member disposed in such a plane and having a pinhole. The light emitted from the light source and passed through the pinhole is received by a photodetector, whereby the positional deviation of the light source is accurately detected. In another aspect of the invention, the detected positional deviation of the light source is automatically adjusted.