Taking optical system for video shooting
US5963377A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 1, 1998 |
| Grant date | Oct 5, 1999 |
| Priority date | — |
| Expiry date | Oct 1, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B15/145527
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A zoom lens system is provided with, from the object side, a first lens unit having a negative optical power, a second lens unit having a positive optical power, a third lens unit having a negative optical power, and a condenser lens unit having a positive optical power. In this zoom lens system, zooming is performed by varying the distances between the first, the second, the third lens unit, and the condenser lens unit. Additionally, this zoom lens system fulfills the condition below: EQU -1.5<.phi.1/.phi.C<-0.4 where .phi.1 represents the optical power of the first lens unit, and .phi.C represents the optical power of the condenser lens unit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.