Wide-angle zoom lens system
US8520316B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Dec 30, 2011 |
| Grant date | Aug 27, 2013 |
| Priority date | — |
| Expiry date | Dec 30, 2031 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B15/143507
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A wide-angle zoom lens system includes a first lens group with negative refraction power, a second lens group with positive refraction power, and a third lens group with positive refraction power. The first lens group, the second lens group, and the third lens group move along an optical axis of the zoom lens system in focusing. The wide-angle zoom lens system satisfies the formulas: 0.77<|f2/f1|<1.1; and 0.7<L2/fT<1.08; wherein f1 is the effective focal length of the first lens group, f2 is the effective focal length of the second lens group, L2 is a distance of the second lens group moving from a wide-angle state to a telephoto state, and fT is the effective focal length of the wide-angle zoom lens system in the telephoto state.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.