Optical lens system for taking image
US7916401B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 19, 2009 |
| Grant date | Mar 29, 2011 |
| Priority date | — |
| Expiry date | Nov 26, 2029 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B13/0035
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An optical lens system for taking image comprises, in order from the object side to the image side: an aperture stop; a first lens element with positive refractive power having a convex object-side surface and a convex image-side surface; a plastic second lens element with negative refractive power having a concave object-side surface, a convex image-side surface and at least one aspheric surface; a plastic third lens element with negative refractive power having a convex object-side surface, a concave image-side surface and at least one aspheric surface. The number of the lens elements with refractive power being limited to three. Focal lengths of the optical lens system, the first lens element, the second lens element and the third lens element are f, f1, f2, f3 respectively; Abbe numbers of the first and second lens elements are V1, V2 respectively, an on-axis distance between second and third lens elements is T23, and they satisfy the relations: 0.8<f/f1<1.8; 0<|f/f2|<0.8; 0<|f/f3|<0.7; 20<V1−V2<38; 0.13<T23/f<0.21.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.