Imaging lens
US8411376B2 · kind B2 · utility
Assignees
Inventor
Key dates
| Filing date | Jun 24, 2011 |
| Grant date | Apr 2, 2013 |
| Priority date | — |
| Expiry date | Jun 24, 2031 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B9/60
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An imaging lens includes an aperture stop, a positive first lens with a biconvex shape, a negative second lens; a negative third lens, a positive fourth lens, and a negative fifth lens arranged in this order from an object side. When the whole lens system has a focal length f, focal lengths and Abbe's numbers of the first and the second lenses are f1, νd1, f2, and νd2, focal lengths of the fourth and fifth lenses are f4 and f5, a composite focal length of the first lens L1 and the second lens L2 is f12, and a distance from a surface of the first lens L1 on the object side to a surface of the fifth lens L5 on the image side is Σd, the imaging lens satisfies the following conditional expressions:0.7<f12/f<1.40.2<|f1/f2|<0.615<νd1−νd20.4<f4/f<1.0Σd/f<1.2|f5/f|<1.0
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.