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:
Apr. 07, 1987
Filed:
Jul. 18, 1984
Yoshinari Hamanishi, Tokyo, JP;
Nippon Kogaku K. K., Tokyo, JP;
Abstract
A rear conversion lens apparatus mounted between an objective lens and a camera body for enlarging the focal length of the composite system of the rear conversion lens apparatus and the objective lens more than the focal length of the objective lens includes a converter barrel removably mounted between the objective lens and the camera body, a lens group of negative refractive power movable along the optic axis within the converter barrel, the lens group of negative refractive power having a forward subgroup and a rearward subgroup, the forward subgroup having a negative meniscus lens disposed most adjacent to the object side and having its convex surface facing the object side and a positive lens disposed on the image side of the negative meniscus lens, and moving means for moving the lens group of negative refractive power along the optic axis. Focusing to objects at infinity to a short distance is effected by the movement of the negative lens group by the moving means.