Zoom lens system
US6304388A · kind A · utility
19Cited by
7References
9Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | May 30, 2000 |
| Grant date | Oct 16, 2001 |
| Priority date | — |
| Expiry date | May 30, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B15/144113
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A zoom lens system for focusing a finite distance object on an image plane as an image, has, in order from one conjugate side, a first lens unit having a positive optical power, the first lens unit being stationary during a zooming operation, a stop stationary during a zooming operation, 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 zooming operation is performed by varying distances between the first through fourth lens units, and the first and second lens units form an afocal condition.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.