Long working distance lens system, assembly, and method
US9874728B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 8, 2016 |
| Grant date | Jan 23, 2018 |
| Priority date | — |
| Expiry date | Mar 18, 2036 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B21/0016
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A lens system includes a tube lens and a lens assembly, with the tube lens disposed between an optical sensor and the lens assembly. The lens assembly is disposed between the tube lens and an imaged object. In order to solve the problem of some lens systems having focal lengths that are shorter than the working distances of the lens systems, one aspect of the inventive subject matter described herein provides the lens assembly with a negative lens and plural positive lenses. A first positive lens is located between a second positive lens and an imaging plane, the second positive lens is located between the first positive lens and the negative lens, and the negative lens is located between the second positive lens and the tube lens.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.