Zoom lens system
US5539582A · kind A · utility
14Cited by
5References
16Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Dec 7, 1992 |
| Grant date | Jul 23, 1996 |
| Priority date | — |
| Expiry date | Dec 7, 2012 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B15/143503
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A zoom lens system is provided with, from the object side, a first lens unit having a negative refractive power, a second lens unit having a positive refractive power and a third lens unit having a negative refractive power. Zooming from a shortest focal length condition to a longest focal length condition is performed by moving all of the lens units while reducing the distance between the first and second lens units and the distance between the second and third lens units. The second lens unit includes three lens elements of a positive lens element, a negative lens element and a positive lens element from the object side.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.