Four mirror unobscurred anastigmatic telescope with all spherical surfaces
US4226501A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 12, 1978 |
| Grant date | Oct 7, 1980 |
| Priority date | — |
| Expiry date | Oct 12, 1998 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B17/0657
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A telescope made only of spherical mirrors including a first mirror system comprising a first, concave spherical mirror and a second, convex spherical mirror have a common center of curvature, the ratio of the radius of said first, concave mirror to said second convex mirror being approximately .sqroot.5+1:.sqroot.5-1, said first mirror arranged to intersect input rays of collimated light and to direct them to said second mirror, said first and second mirrors arranged off axis so as to not obstruct the light path to said first mirror; and a second mirror system comprising at least a third, concave mirror and a fourth, convex mirror having a common center of curvature, the radius of said third mirror being approximately twice the radius of said fourth mirror, said third mirror positioned to intersect light reflected from said second mirror and to reflect it to said fourth mirror, said fourth mirror reflecting light back to said third mirror from which it is reflected to form a real image, the optical axis of said system being defined by a line between the centers of curvature of said first and second systems.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.