Apparatus and method for filtering light in a thermal processing chamber
US5960158A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 11, 1997 |
| Grant date | Sep 28, 1999 |
| Priority date | — |
| Expiry date | Jul 11, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01J5/06
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The present invention is directed to an apparatus and process for filtering light in a thermal processing chamber. In particular, the apparatus of the present invention includes a first spectral filter spaced apart from a second spectral filter. The first spectral filter is spaced apart from the second spectral filter so as to define a cooling fluid channel therebetween through which a cooling fluid can be circulated. In order to prevent thermal radiation being emitted by the light source from interfering with the operation of a radiation sensing device contained in the chamber, the first spectral filter absorbs most of the thermal radiation being emitted by the light source at the operating wavelength of the radiation sensing device. The second spectral filter, on the other hand, is substantially transparent to thermal radiation at the operating wavelength of the radiation sensing device. If desired, various reflective coatings made from dielectric materials can also be applied to selected surfaces of the spectral filters to further prevent unwanted thermal radiation from being detected by the radiation sensing device and for preventing the spectral filters from increasing in temp…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.