Imaging lens
US7508601B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 29, 2007 |
| Grant date | Mar 24, 2009 |
| Priority date | — |
| Expiry date | May 29, 2027 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B13/22
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An imaging lens includes, in order from an object side, a first lens with a positive refractive power having a biconvex shape; an aperture stop having a predetermined aperture diameter; a second lens with a positive refractive power having a concave surface on the object side, at least one of the object-side surface and an image-plane-side surface of the second lens being aspherical; and a third lens with a negative refractive power having a concave surface on the object side and an aspherical surface with an inflection point in an effective-diameter area on the image-plane side, whereby aberrations can be effectively corrected, the total length of the lens system can be reduced to reduce the overall size, in particular the thickness, and a shutter can be readily accommodated.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.