Zoom lens
US7760440B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 31, 2008 |
| Grant date | Jul 20, 2010 |
| Priority date | — |
| Expiry date | Jan 21, 2029 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B15/144113
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
The zoom lens 100 comprises, sequentially from the object side, a stationary first lens group 110 having positive refractive power; a second lens group 120, having negative refractive power, and that moves on the optical axis when changing the magnification; a stationary third lens group 130 that has positive refractive power; and a fourth lens group 140, having positive refractive power. The first lens group 110 comprises six lenses. The second lens L2 is a meniscus lens that is formed so as to have at least one aspherical surface. The aspherical surface of the second lens L2 is formed at the shape wherein there is no displacement in the thickness from the center portion to the edge portion. Doing so enables the effective correction of distortion and off-axis aberration on the wide-angle side, and the provision of a high-performance zoom lens that is small and has a high variable magnification.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.