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. 25, 1988
Filed:
Sep. 22, 1987
Kenji Nishi, Kawasaki, JP;
Hidemi Kawai, Yokohama, JP;
Kazuaki Suzuki, Tokyo, JP;
Makoto Uehara, Tokyo, JP;
Nippon Kogaku K. K., Tokyo, JP;
Abstract
The projection optical apparatus includes light-emitting means which are disposed on a stage movable along the image plane in the projection optical apparatus and which define a light-emitting plane having a predetermined shape; photoelectric detection means which is disposed at a position substantially in conjugate relationship with a pupil of said projection optical apparatus and which receives the light emitted from the light-emitting plane of the light-emitting means through the projection optical system and a mask in which a pattern is defined at a predetermined position; and position detection means which controls the stage in such a way that the image projected on the light-emitting plane is shifted in relation to the mask pattern and which detects the superposed position between the image and the pattern in response to the light signal derived from the photoelectric detection means while the projected image is shifted and to the position of the stage.