Variable-magnification observation optical system
US9869850B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | May 1, 2014 |
| Grant date | Jan 16, 2018 |
| Priority date | — |
| Expiry date | Jul 25, 2034 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B27/0025
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A variable-magnification observation optical system includes an objective system, an erecting system, and an eyepiece system. The objective system includes a positive first group, a positive second group, and a negative third group in order from the object side. The eyepiece system includes a positive fourth group and a positive fifth group in order from the object side. The erecting system is located between the first group and the second group. The fifth group includes in order from the object side a negative meniscus lens and a positive lens with an air gap therebetween wherein the negative meniscus lens has a concave surface facing the object. The fifth group has at least one aspheric surface.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.