Elastically compensated off-axis mirror
US4043644A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 15, 1976 |
| Grant date | Aug 23, 1977 |
| Priority date | — |
| Expiry date | Jul 15, 1996 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B26/0825
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A reflecting mirror with an active optical surface approximating a sphere is elastically deformed for off-axis use. The mirror, preferably symmetrical about an axis normal to its center point, is circular in peripheral configuration. The active optical surface is ground on a circular face of the mirror. This surface can be ground to be equal to or to exceed the F-stop of 2.5. The mirror has a thickness at its central point in the range of one fifth to one fifteenth of its diameter, with a thickness of one tenth of the diameter being preferred. The reverse and non-optically active side of the mirror is provided with a curvature in anticipation of its elastic deformation for off-axis use. This reverse curvature is a spherical surface having a different radius of curvature complementary to the curvature of the active optical surface. This different radius of curvature is chosen so that the decrease in mirror thickness at the mirror edge compared to the thickness at the mirror center is in the preferred range of 0.33. An intermediate ratio in the range of 0.27 to 0.39 and a broad ratio in the range of 0.21 to 0.42 are disclosed. A harness for bending the mirror in an adjustably reprodu…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.