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:
Nov. 02, 2004
Filed:
May. 22, 2001
Hitoshi Hatada, Kawasaki, JP;
Masaki Kato, Yokohama, JP;
Motoo Koyama, Tokyo, JP;
Hiroshi Shirasu, Yokohama, JP;
Masahiro Iguchi, Tokyo, JP;
Nikon Corporation, Tokyo, JP;
Abstract
The memory unit stores the correlation of the positional change in the image planes of the projection optical modules in the focusing direction and the light quantity change. The image plane position determination unit finds the positional change value of the image planes of the projection optical modules based on the correlation information that is stored in the memory unit and the information on changes in the amount of light that is emitted to the projection optical modules. The compensation value calculating unit calculates the compensation value corresponding to the change in the amount of curvature in the image planes of the projection optical modules. The compensating unit compensates the change value in conformity with the compensation value. The focus compensation optical system is driven based on the change value that is compensated.