Zoom lens system having enlarged range of variation in magnification
US4015895A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 14, 1975 |
| Grant date | Apr 5, 1977 |
| Priority date | — |
| Expiry date | Aug 14, 1995 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B15/02
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A zoom lens system wherein the distance between the rearmost lens surface in the afocal zooming lens portion and the foremost lens surface in the image forming lens system is kept unchanged and an afocal magnification varying lens is inserted into the above described distance so as to enlarge the telefoto range, the magnification varying lens consisting of a front convergent lens group and a rear divergent lens group. The requirements for the magnification varying lens are so set that compensation for aberrations is kept in superior condition when zooming is effected by the lens system with the magnification varying lens being eliminated therefrom, while, when zooming is effected under the condition the magnification varying lens is added to the lens system, the aberrations are also well compensated for.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.