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:
Mar. 17, 1987
Filed:
Mar. 29, 1985
Hidenori Terasawa, Kawasaki, JP;
Nippon Kogaku K. K., Tokyo, JP;
Abstract
The wide angle and variable magnification lens system for finite distance consists of a first lens group whose focal length is negative as a whole, a second lens group whole focal length is positive as a whole, an aperture stop, a third lens group whose focal length is positive as a whole and a fourth lens group whose focal length is negative as a whole arranged in the named order from the object side and symmetrically relative to said aperture stop. The focal length of the total lens system is variable by changing the spacing between the first and the second lens groups and the spacing between the third and fourth lens groups by approximately the same amount. The first lens group comprises, in the order from the object side, a first component of a negative meniscus lens with its concave surface facing to the aperture stop, a second component of a negative lens and a third component of a positive meniscus lens with its convex surface facing toward the object side, and the fourth lens group comprises, in the order from the image side, a tenth component of a negative meniscus lens with its concave surface facing to the aperture stop, a ninth component of a negative lens and an eighth component of a positive meniscus lens with its convex surface facing toward the image side.