Zoom lens system
US6101043A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 24, 1999 |
| Grant date | Aug 8, 2000 |
| Priority date | — |
| Expiry date | Feb 24, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B15/144113
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A zoom lens system has, from the object side, a first lens unit having a positive optical power, a second lens unit having a negative optical power, a third lens unit having a positive optical power, and a fourth lens unit having a positive optical power. The first, second, and fourth lens units are moved during zooming. The third lens unit is fixed during zooming. The following conditions are fulfilled: EQU -5.0<M1 Ymax<-1.0 EQU -1.0<M4 M2 <-0.1 where M1 represents the displacement amount of the first lens unit from the shortest focal length condition to the longest focal length condition; M2 represents the displacement amount of the second lens unit from the shortest focal length condition to the longest focal length condition; M4 represents the displacement amount of the fourth lens unit from the shortest focal length condition to the longest focal length condition; and Ymax represents the maximum image height.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.