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:
Jul. 15, 2008
Filed:
Mar. 28, 2007
Akira Sawamoto, Suwa, JP;
Akira Sawamoto, Suwa, JP;
Nittoh Kogaku K.K., Nagano, JP;
Abstract
A zoom lens system that has two lens groups with respectively negative and positive refractive powers in that order from a display medium, such as a screen, side is provided. The first lens group and the second lens group respectively include at least one aspherical surface. An air distance dw between the first lens group and the second lens group at the wide angle end, an air distance dt between the first lens group and the second lens group at the telephoto end, a combined focal length fof the first lens group, a combined focal length fof the second lens group, and the combined focal length fw of the zoom lens system at the wide angle end satisfy the following conditions: 0.05<dt/dw<0.1; dt<2.5 mm; 1.3<|f/fw|<1.6; 1.1<|f/f|<1.4.