Patterned optical interference coatings for electric lamps
US5676579A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 27, 1996 |
| Grant date | Oct 14, 1997 |
| Priority date | — |
| Expiry date | Aug 27, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J65/048
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An interference filter or coating is provided in a predetermined pattern on a lamp envelope. The coating is comprised of alternating layers of high and low index of refraction materials applied to a vitreous outer surface of a lamp envelope. The coating may be geometrically symmetric or asymmetric, continuous or discontinuous with respect to the coating itself or the envelope to which it has been applied. The envelope can be masked prior to deposition of the coating so that removal of the mask leaves the filter in the desired pattern. The preferred process for forming the coating includes forming a boric oxide mask on a portion of the envelope, applying the coating over the mask and removing the coating from masked areas of the envelope by dissolving the mask in an aqueous solution.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.