Zoom lens system
US6002529A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 9, 1996 |
| Grant date | Dec 14, 1999 |
| Priority date | — |
| Expiry date | Aug 9, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B15/144105
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A zoom lens system for use in a compact lens shutter camera has excellent optical properties at a high zoom ratio of 4-5 across the entire zoom range with a small number of lenses. The zoom lens system has, from the object side to the image side, a positive first lens unit, a negative second lens unit, a positive third lens unit and a negative fourth lens unit, wherein the air spaces between each lens unit vary during a zooming operation. The zoom lens system fulfills predetermined conditions related to the back focal distance, the shifting amount of the second and third lens units during zooming and the thickness of the third lens unit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.