Extender lens and imaging apparatus
US10698187B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 4, 2018 |
| Grant date | Jun 30, 2020 |
| Priority date | — |
| Expiry date | Mar 1, 2039 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B13/18
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An extender lens is removably inserted into a master lens, performs an increase in a focal length without changing an imaging position due to insertion, and consists of a positive first lens group and a negative second lens group in order from the object side. The first lens group consists of one or more positive lenses in order from the object side, and a three-lens cemented lens having three lenses of a positive lens, a negative lens, and a positive lens having cemented together in order from the object side. The following Conditional Expression (1) relating to an Abbe number ν1n of the negative lens of the three-lens cemented lens is satisfied: 26<ν1n<40. (1):
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.