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. 24, 2012
Filed:
Jul. 06, 2010
Sachiko Nasu, Tokyo, JP;
Sachiko Nasu, Tokyo, JP;
Hoya Corporation, Tokyo, JP;
Abstract
An objective lens for an endoscope, including a negative front lens group and a positive rear lens group arranged such that an aperture stop is positioned therebetween, wherein the front lens group has at least a front-side negative lens and a front-side positive lens arranged in this order from an object side, and the rear lens group has at least a rear-side positive lens and a cemented lens arranged in this order from the object side, the cemented lens being configured by cementing together negative and positive lenses. The objective lens satisfies following conditions: −4.5≦f/f≦−2.0 and 1.5≦f/f≦2.5, where f(unit: mm) represent of the front lens group, f (unit: mm) represents a total focal length of the front lens group and the rear lens group, and f(unit: mm) represents a focal length of the rear-side positive lens.