Optical attachment for reducing the focal length of an objective lens
US8903232B1 · kind B1 · utility
29Cited by
6References
18Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Jul 12, 2014 |
| Grant date | Dec 2, 2014 |
| Priority date | — |
| Expiry date | Jul 12, 2034 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B15/10
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An optical attachment having five or six elements and configured to be operably arranged on the image side of an objective lens to reduce the focal length and focal ratio of the objective lens is disclosed. The optical attachment is particularly suitable for adapting objective lenses designed with a relatively large working distance for a large format size to cameras having a smaller format size and relatively small permissible working distance. The optical attachments disclosed herein have high image quality at large aperture over a large field of view, and can be well-corrected for all major aberrations.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.