Single focus lens
US6762890B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 5, 2003 |
| Grant date | Jul 13, 2004 |
| Priority date | — |
| Expiry date | Feb 5, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B13/22
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A single focus lens is composed of four lens components of negative, positive, negative and positive refractive power, respectively, in order from the object side. The first lens, in order from the object side, has a concave surface on the image side, and a stop is positioned between the first lens and the second lens. The second lens has a convex surface on the object side, the third lens has a concave surface on the object side, and the fourth lens has a convex, aspherical surface on the image side such that the refractive power of the fourth lens becomes weaker towards the edge of the lens. Specified conditions are preferably satisfied in order to provide favorable correction of aberrations.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.