High emissivity article having multiple layers of a material of high internal stress
US4850660A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 29, 1987 |
| Grant date | Jul 25, 1989 |
| Priority date | — |
| Expiry date | Jul 29, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B1/115
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
The article, typically for use in man-made satellites, has high emissivity and low reflectance in the thermal infra-red wavebands between 6 and 30 microns, and also in the visible wavebands. The article is employed either to cover individual solar-cells, thereby protecting the cells from ionizing radiation and micro-meteoroids, and to protect the adhesive bonding the article to the solar cell from u-v light, or as a thermal control mirror to prevent heat build-up. The article has good emissivity in the thermal waveband regions, so the cell can be maintained at a relatively low temperature. The article employs a high internal stress material and a preferred embodiment comprises a glass substrate having a high emissivity coating comprising a stack of multiple relatively thin alternate layers of dysprosium fluoride and silicon oxide disposed immediately adjacent the substrate, and on the other hand, disposed above these layers, remote from the substrate, an anti-reflection coating comprising alternate layers of erbium oxide and dysprosium fluoride and an upper layer of silicon oxide.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.