Zoom lens system
US6118592A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 29, 1998 |
| Grant date | Sep 12, 2000 |
| Priority date | — |
| Expiry date | Sep 29, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B15/144105
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A zoom lens system has four or five lens units with the optical powers being +/-/+/- or +/-/+/+/-, respectively, from the object side. The image side lens unit has a negative optical power and is movable, along with at least one other lens unit, in a zooming operation. The zoom lens system satisfies the following conditions: 0.6<LBw/fw<1.7 and 0.6<.vertline.fN/fw.vertline.<1.7, where LBw represents a back focus length at the shortest focal length condition; fw represents a focal length of the zoom lens system at the shortest focal length condition; and fN represents a focal length of the image side lens unit. The lens system can be employed with a solid state imaging device, and an optical low-pass filter and an infrared blocking filter can be positioned between the lens system and the imaging unit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.