Visible transmitting and infrared reflecting filter
US4229066A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 20, 1978 |
| Grant date | Oct 21, 1980 |
| Priority date | — |
| Expiry date | Sep 20, 1998 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC03C17/3476
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
Visible transmitting and infrared reflecting filter having a substrate formed of a material capable of transmitting visible light or absorbing visible light and having a surface and a coating carried by the surface of the substrate. The coating comprises at least one period of a multilayer stack which is reflecting in the infrared and transmitting at shorter wavelengths. The period is formed of a plurality of layers of high and low index materials with alternate layers being formed of materials having a high index of refraction and the other layers being formed of materials having a low index of refraction. At least one anti-reflection layer is disposed between adjacent layers of the period for matching the layers of the period to each other in the visible so that the transmission of the filter is relatively high over a relatively wide wavelength band at shorter wavelengths while maintaining high reflection and low absorption at the longer wavelengths.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.