Zoom lens system and electronic image pickup apparatus using the same
US7339745B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 14, 2006 |
| Grant date | Mar 4, 2008 |
| Priority date | — |
| Expiry date | Dec 14, 2026 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B15/143503
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A zoom lens system comprising, a first negative lens unit; a second positive lens unit; and a third negative lens unit, wherein a space between the second and third lens units changes during magnification change or focusing operation; the second lens unit and the third lens unit move only to the object side during the magnification change from a wide-angle end to a telephoto end so that a space between the first and second lens units is narrower in the telephoto end than in the wide-angle end; the first lens unit comprises a negative lens and a positive lens; the second lens unit comprises at most three lenses; the third lens unit comprises a negative lens; and the following condition (1) is satisfied:0.7<Cj(t)/Cj(w)<1.2. (1)
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.