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. 24, 1985
Filed:
Jun. 26, 1984
Hidenori Terasawa, Kawasaki, JP;
Nippon Kogaku K.K., Tokyo, JP;
Abstract
A symmetrical type projection lens comprises first lens composed of positive and negative lenses disposed in the order starting from the object side and cemented to each other. The first lens is in the form of a meniscus lens having its convex face at the object side and having a total negative focal length. The projection lens comprises a second lens which is in the form of a positive meniscus lens having its convex face at the object side, a stop, third lens which is in the form of a positive meniscus lens having its convex face at the image side, and fourth lens composed of negative and positive lenses cemented to each other and being in the form of a meniscus lens which is convex at the image side and has a total negative focal length. The first and second lenses are symmetrically arranged respectively relative to the third and fourth lenses about the stop. The projection lens satisfies the certain conditions.