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. 15, 1988
Filed:
May. 30, 1986
Sadao Okudaira, Tokyo, JP;
Asahi Kogaku Kogyo Kabushiki Kaisha, Tokyo, JP;
Abstract
A compact and high-performance bright wide-angle zoom lens comprising, in order from the object side, a front group having a negative refractive power and a rear group having a positive refractive power, with a stop diaphragm being disposed between the front and rear groups. The front group, stop diaphragm and rear groups are capable of independent mechanical movement in response to a change in the focal length of the overall system. The rear group having a positive refractive power is composed, in order from the object side, of a positive lens unit, a negative lens unit, and a positive lens unit, with a lens element having a refractive index gradient profile along the optical axis being disposed in the positive lens unit on the image side of the rear group.