Zoom Lens
US6124987A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 23, 1999 |
| Grant date | Sep 26, 2000 |
| Priority date | — |
| Expiry date | Jun 23, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B15/1425
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A zoom lens includes a front lens group having a negative power as a whole and a rear lens group having a positive power as a whole, and a stop included therein. For zooming, the front and rear lens groups are moved relative to each other on an optical axis. For focusing, only a rearmost positive lens of the rear lens group is moved. The zoom lens satisfies the following conditions: EQU 0.5<ff/fR<5.0 EQU 0.01<.beta.f<1.00 EQU -1.0.ltoreq.r1/r2.ltoreq.0.3 wherein fR represents a synthetic focal length of the rear lens group, ff represents a focal length of the rearmost positive lens, .beta.f represents an image magnification of the rearmost positive lens, r1 represents a radius of curvature of an object side surface of the rearmost positive lens, and r2 represents a radius of curvature of an image side surface of the rearmost positive lens.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.