Zoom lens capable of changing a range of variable focal length
US5097360A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 5, 1991 |
| Grant date | Mar 17, 1992 |
| Priority date | — |
| Expiry date | Aug 5, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B15/1421
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A zoom lens capable of changing the range of variable focal length to another limit, comprising, from front to rear, a zoom section including a variator and a compensator arranged upon zooming movement to vary the focal length in a predetermined range, a diaphragm, and a relay lens section receptive of the afocal light beam from the zoom section to form an image and having a front lens unit and a rear lens unit, the front lens unit being provided with a fixed sub-unit and an interchangeable sub-unit in this order from the front, wherein the interchangeable sub-unit is removed to create a space between the fixed sub-unit and the rear lens unit, into which a range changing lens unit is then inserted, so that the range of variable focal length is changed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.