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. 24, 2000
Filed:
Jul. 19, 1999
Kimiaki Nakazawa, Saitama, JP;
Fuji Photo Optical Co., Ltd., Omiya, JP;
Abstract
To correct on-axis chromatic aberration of a projection lens easily and at low cost by using a transparent plate between an optical modulator for a primary color component and a beam combining optical system. When a standard projection lens 11 having a medium focal length is used, parallel-plane glass plates 27, 28, and 29 of the same thickness (1 mm for example) may be inserted in each component beam. However, when the projection lens is changed to one having a different focal length, at least one of the parallel-plane glass plates is replaced in order to suppress the occurrence of on-axis chromatic aberration for that color component caused by the change in focal length.