Zoom lens
US9250421B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Dec 2, 2013 |
| Grant date | Feb 2, 2016 |
| Priority date | — |
| Expiry date | Jan 2, 2034 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N23/00
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A zoom lens includes, sequentially from an object side, a positive first lens group, a negative second lens group, a positive third lens group, and a positive rear lens group. During zooming from a wide angle position to a telephoto position, an interval between the first lens group and the second lens group increases, and an interval between the second lens group and the third lens group decreases. The rear lens group includes a positive first sub-group, a negative second sub-group, and a positive third sub-group, and focusing is performed by moving the second sub-group toward an image surface side. The zoom lens satisfies the following conditions: 0.2<frt/ft<1.8 and 0.2<|fb|/frt<1.0, where “frt” denotes a focal length of the rear lens group at the telephoto position, “fb” denotes a focal length of the second sub-group, and “ft” denotes a focal length of the zoom lens at the telephoto position.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.