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:
Jun. 04, 2013
Filed:
Aug. 23, 2011
Saburo Masugi, Kawasaki, JP;
Saburo Masugi, Kawasaki, JP;
Nikon Corporation, Tokyo, JP;
Abstract
A zoom lens includes, in order from an object, a first lens group Ghaving negative refractive power; a second lens group Ghaving positive refractive power; and a third lens group Ghaving positive refractive power. The first lens group Gcomprises only one negative spherical lens (lens L) and one plastic positive lens (lens L) separated by an air gap. The second lens group Gcomprises three or fewer lenses, including a positive lens component (cemented lens comprising a lens Land a lens L), and one plastic negative lens (lens L). The following conditional expressions are satisfied: 0.50<fPL/(−fPL)<2.50 and 0.80<(−f)/f<1.35, where fPL is a focal length of the plastic positive lens forming the first lens group G, fPL is the focal length of the plastic negative lens forming the second lens group G, fis the focal length of the first lens group G, and fis the focal length of the second lens group G