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. 05, 1977
Filed:
May. 02, 1975
Kunihiko Konoma, Sakai, JA;
Kaname Satou, Torrance, CA (US);
Minolta Camera Kabushiki Kaisha, Osaka, JA;
Abstract
A four element lens system for use on a camera and the like comprises two positive meniscus lens having two negative meniscus lens interposed between the positive lens. The optical axis of each lens elements being aligned with an aperture stopper element or its functional equivalent between the negative lens elements. The position of the effective plane of the aperture stopper satisfying the following equation: ##EQU1## wherein S is a distance along the optical axis between lens elements, S'.sub.2, is the distance between the surface of the second negative meniscus lens and the effective plane of the aperture stopper and S'.sub.2 is the distance between the effective plane of the aperture stopper and the surface of the third negative meniscus lens. Preferably each of the lens elements is injection molded from a plastic material with both of the positive lens elements and the negative lens elements being identical lens. As a result of the present invention, an image may be formed having relative low aberration from a portrait distance to a landscape distance in a camera that requires only the manufacture of two types of plastic lenses.