Enhanced variable power zoom lens
US8451549B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | May 20, 2011 |
| Grant date | May 28, 2013 |
| Priority date | — |
| Expiry date | Jun 23, 2031 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B15/145105
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
The present invention is directed to provide an enhanced variable power zoom lens that is lightweight as a whole, and especially, has its focusing lens optics reduced in weight so as to relieve of a load on a focusing drive system, and that has its anti-vibration lens optics reduced in both diameter and weight so as to relieve of a load on an anti-vibration drive system and downsize the same. The enhanced variable power zoom lens is adapted to have the foremost or first lens group of positive refractivity, the second lens group of negative refractivity, the third lens group of positive refractivity, the fourth lens group of negative refractivity, and the fifth lens group arranged in this sequence from a position closer to the object where a distance between each pair of the adjacent lens groups is varied during zooming from the wide-angle end to the telephoto end, each lens group comes closer to the object at the telephoto end than at the wide-angle end, the third lens group and the fourth lens group separating the farthest apart from each other at the intermediate zooming range, and the fourth lens group is moved closer to the image plane for shifting from infinity focusing to pro…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.