Radiation emitting apparatus
US4575786A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 12, 1983 |
| Grant date | Mar 11, 1986 |
| Priority date | — |
| Expiry date | Apr 12, 2003 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF21Y2103/00
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A modulated optical radiation beacon, e.g. a flashing light beacon or an IR emmissive missile jamming source, can comprise a radiation source and two relatively movable apertured masks which, as the apertures thereof move into and out of registration, pass or block the radiation from the source. Herein, to improve the uniformity of the polar distribution of the emitted radiation (assuming, of course, that a uniform distribution is required) or, in other cases, simply to improve efficiency, the apertures of the `inner` mask, i.e. the one nearest the source, are bounded by curved reflective surfaces defining an optical cavity which at least crudely images the source at a position near the outer mask. Advantageously, the optical cavities are defined by a spaced array of prismatic members having appropriately curved facing surfaces.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.