Zoom lens
US6236517A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 6, 1999 |
| Grant date | May 22, 2001 |
| Priority date | — |
| Expiry date | Apr 6, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B15/144507
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A zoom lens includes from an object side to an image side, at a wide-angle end, a first lens group whose overall refractive power is positive and a second lens group whose overall refractive power is negative. Zooming is performed by varying the separation between the first lens group and the second lens group. The second lens group includes a first lens unit of negative refractive power and a second lens unit of negative refractive power. Focusing is performed by varying the separation between the first lens unit and the second lens unit. The first lens group has a plurality of lens units, and the separation between each adjacent two of the plurality of lens units varies during zooming.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.