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:
Jun. 25, 1985
Filed:
Feb. 28, 1983
Tokyo Shibaura Denki Kabushiki Kaisha, Kawasaki, JP;
Abstract
A zoom lens having, from front to rear, a 1st lens group having a positive refractive power for focusing, a 2nd lens group of negative refractive power having a magnification changing function, a 3rd lens group having a negative refractive power for compensating for the image shift resulting from the change of the magnification, and a 4th lens group of positive refractive power having an image forming function, the aforesaid 4th lens group having two lens groups with the front or 4-1st lens group and the rear or 4-2nd lens group. The form and construction and arrangement of the lens elements of the aforesaid 4-1st and the aforesaid 4-2nd lens groups are properly set forth so as to achieve good correction of aberrations and, at the same time, limiting the bulk and size of the entire system to a minimum.