Afocal zoom lens system for stereoscopic microscopes
US6157495A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 21, 1998 |
| Grant date | Dec 5, 2000 |
| Priority date | — |
| Expiry date | Sep 21, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B21/22
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An afocal zoom lens system comprising a first positive lens unit, a second negative lens unit, a third positive lens unit and a fourth negative lens unit, wherein the first lens unit and the fourth lens unit are kept stationary, the second lens unit is moved so as to vary an airspace reserved between the first lens unit and the second lens unit, and an airspace reserved between the second lens unit and the third lens unit, the third lens unit is moved so as to vary an airspace reserved between the second lens unit and the third lens unit, and an airspace reserved between the second lens unit and the third lens unit, and an airspace reserved between the third lens unit and the fourth lens unit. The afocal zoom lens system for stereoscopic microscopes satisfies the following condition (1): EQU 0.6<f.sub.3 /f.sub.1 <0.7 (1).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.