Zoom lens
US7190529B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 2, 2005 |
| Grant date | Mar 13, 2007 |
| Priority date | — |
| Expiry date | Nov 2, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B15/144113
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
The invention is concerned with a high-zoom-ratio, high-performance zoom lens that is much more improved in compactness. The zoom lens comprises a first lens group G1 of positive refracting power, a second lens group G2 of negative refracting power, a third lens group G3 of positive refracting power and a fourth lens group G4 of positive refracting power, with a varying space between adjacent lenses during zooming. Upon zooming from the wide-angle end to the telephoto end of the zoom lens system, the first lens group G1 is positioned nearer to the object side at the telephoto end than at the wide-angle end. The zoom lens of the invention satisfies a specific condition for properly defining the refracting power of the first lens group and a specific condition for defining the transverse magnification of the second lens group.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.