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:
May. 04, 1984
Mitsuhiro Tokuhara, Chigasaki, JP;
Yu Yamada, Tokyo, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
A variable magnification optical system includes two movable groups of the so-called symmetric orthometer type each of which includes a positive power lens, a negative power lens and a meniscus positive lens that are in sequence disposed symmetrically with respect to a diaphragm, said optical system further including negative lenses mounted outside said movable groups symmetrically with respect to said diaphragm to form a fixed group, said movable groups being moved along the optical axis relative to said fixed group in symmetrical fashion with respect to said diaphragm to vary the focal length of said optical system, the entire optical system being moved as one body to bring the object and image planes into a position that they are optically conjugate with each other.