Zoom lens system and electronic image pickup apparatus using the same
US8102606B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Nov 14, 2007 |
| Grant date | Jan 24, 2012 |
| Priority date | — |
| Expiry date | Oct 28, 2030 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B15/144113
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A zoom lens system includes, in order from an object side, a first lens unit G1 having a positive refracting power, a second lens unit G2 having a negative refracting power, a third lens unit G3 having a positive refracting power, and a fourth lens unit G4 having a positive refracting power, and at the time of zooming from a wide angle end to a telephoto end, a space between the lens units changes, and the second lens unit includes not more than three lenses, and a biconcave negative lens which satisfies the following conditional expression (1) is disposed nearest to the object side, in the second lens unit, and (the zoom lens system) is characterized by satisfying the following conditional expression (2)−0.1<SF2n1<0.5 (1)3.0<ft/fw<12.0 (2).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.