Patent · US Active

Zoom lens

US7944620B2 · kind B2 · utility

10Cited by

16References

19Claims

0Family size

Assignee

Young Optics Inc. · TW

Inventors

Kuo-Chuan Wang · 東區, TW
Ching-Lung Lai · Hsinchu, TW

Key dates

Filing date	Sep 22, 2009
Grant date	May 17, 2011
Priority date	—
Expiry date	Dec 4, 2029

Classification

Technology area (CPC G)Physics
CPC primaryG02B13/12
WIPO fieldOptics
WIPO sectorInstruments

Abstract

A zoom lens includes a first lens group and a second lens group disposed between the first lens group and an image side. The first lens group has three lenses. Refractive powers of the three lenses arranged from an object side to the image side are respectively negative, negative, and positive. The second lens group has five lenses. Refractive powers of the five lenses arranged from the object side to the image side are respectively positive, negative, positive, negative, and positive. Effective focal lengths (EFL) of the first and the second groups are respectively f1 and f2. The EFL of the zoom lens is fw when the zoom lens is switched to a wide end. The zoom lens satisfies −2.8<f1/fw<−2.5 and 0.75<|f1/f2|<0.9.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.