Compact eyepiece using an imersed field lens
US8456745B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | May 12, 2011 |
| Grant date | Jun 4, 2013 |
| Priority date | — |
| Expiry date | Aug 2, 2031 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B25/001
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A first embodiment is a lens system having a plurality of refractive and reflective spherical elements that work as a magnifier to produce a distortion free, less than 1%, image with optical correction over a wide field of view. The system has at least one concave reflecting surface, and at least three convex refracting surfaces with the sign of the radius of one of the convex refracting surfaces being opposite of the sign of the radius of remaining two convex refracting surfaces. A second embodiment is a lens having a concave reflecting element which is on a substrate that is a negative lens by transmission with an index of refraction between 1.6<nd >2.0 and a dispersion 49<νd>15. This is used in combination with at least 3 positive refracting surfaces with less dispersive power than the negative element and with the sign of the radius of one of the positive elements being opposite from the sign of the radius of the remaining positive elements.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.