Imaging lens and image pickup apparatus
US7746572B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Aug 20, 2008 |
| Grant date | Jun 29, 2010 |
| Priority date | — |
| Expiry date | Dec 20, 2028 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B9/34
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An imaging lens comprises, in order from an object side: a first lens that has a negative refractive power and is convex toward the object side; a second lens that has a positive refractive power and is a meniscus lens convex toward the object side; a stop; a third lens that has a positive refractive power and is convex toward an image side; and a cemented lens that has a positive refractive power as a whole and is formed by cementing a fourth lens and a fifth lens, wherein assuming that an Abbe number of the second lens with respect to d-line is ν2, a distance on an optical axis from a vertex of a surface of the first lens facing toward the object side to an image plane of the imaging lens is L, a focal length of the imaging lens is f, and a back focus of the imaging lens is Bf, the following conditional expressions (1) to (3) are satisfied:ν2>30 (1),2.5<L/f<4.0 (2), and0.5<Bf/f<1.3 (3).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.