Patent · US Expired

High pressure sodium lamp containing barium getter

US4333032A · kind A · utility

7Cited by
5References
7Claims
0Family size

Assignee

Inventors

Key dates

Filing dateSep 25, 1978
Grant dateJun 1, 1982
Priority date
Expiry dateSep 25, 1998

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH01J61/26
  • WIPO fieldElectrical machinery, apparatus, energy
  • WIPO sectorElectrical engineering

Abstract

A high pressure sodium lamp comprises an elongated arc tube within an evacuated outer jacket, the arc tube containing a fill including sodium and mercury. A barium getter film is disposed on the inner jacket wall at one end thereof. The film is longitudinally spaced more than 1 cm away from the end of the arc tube in order to reduce photoelectron emission from the barium which can cause sodium migration from the arc tube.

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