Zoom lens having an easily changeable range of variable focal distance
US4157211A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 15, 1977 |
| Grant date | Jun 5, 1979 |
| Priority date | — |
| Expiry date | Mar 15, 1997 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B15/12
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A zoom lens having a lens part for focusing, a zooming part consisting of a plurality of movable lens groups to vary focal distance, and a lens part for imaging in the rear of the zoom lens. The lens part for imaging consists of a front group. A rear group and a variable magnification lens group can be mounted at and dismounted from a position between the front group and rear group. A range of variable focal distance can be easily changed by shifting a portion of lenses positioned closer to the image side of a diaphragm in order to separate further an exit pupil of the total system from an imaging plane as the variable magnification lens group is mounted.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.