Patent · US Expired

Sulfur/selenium lamp with improved characteristics

US5866980A · kind A · utility

22Cited by
30References
35Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJun 7, 1995
Grant dateFeb 2, 1999
Priority date
Expiry dateJun 7, 2015

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH01J65/048
  • WIPO fieldElectrical machinery, apparatus, energy
  • WIPO sectorElectrical engineering

Abstract

The spectral energy characteristic of a discharge lamp is controlled by changing the density of the fill substance. The spectral characteristic can be shifted while substantially maintaining its shape by changing the density of the fill. A sulfur or selenium containing discharge lamp which is operated at a pressure of at least about 1 atmosphere contains a low ionization potential substance in the fill. Characteristics which are improved are one or more of spatial color uniformity, extinguishing characteristics, and bulb starting reliability. Particular substances which are added to the fill are alkali metal containing substances, III B metal containing substances, and alkaline earth metal containing substances. When light is reflected back into the bulb, the light which is re-emitted is stronger in the higher wavelengths.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.