Zoom lens
US5751497A · kind A · utility
6Cited by
5References
4Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Oct 30, 1996 |
| Grant date | May 12, 1998 |
| Priority date | — |
| Expiry date | Oct 30, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B15/17
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A high range zoom lens is disclosed, comprising, from front to rear, a first lens unit of positive refractive power, a second lens unit of negative refractive power, a third lens unit of positive or negative refractive power and a fourth lens unit of positive refractive power, the second and third lens units being movable for zooming, wherein an aspheric surface is introduced into the second or third lens unit at a specified location so that the variation of aberrations with zooming is as far reduced for high performance as possible.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.