Zoom lens
US7362509B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Apr 27, 2005 |
| Grant date | Apr 22, 2008 |
| Priority date | — |
| Expiry date | Jun 29, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B15/1425
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A zoom lens includes, in sequence from the object side: a first lens group with an overall negative refractive power; and a second lens group with an overall positive refractive power. A zoom factor changes by moving the second lens group. Focal adjustments are made by moving the first lens group accompanied by the change of the zoom factor made by the movement of the second lens group. The first lens group includes a first lens having a negative refractive power and a second lens having a positive refractive power. The second lens group includes a third lens having a positive refractive power, a fourth lens with a positive refractive power and a fifth lens with a negative refractive power bonded together, and a sixth lens with a positive refractive power. The bonded lenses form a meniscus shape with a convex surface facing the object side. The resulting lens is short in length, compact, thin, and suitable for digital still cameras.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.