Patent · US Expired

Method and device for lighting ultra-high pressure discharge lamps

US6788009B2 · kind B2 · utility

9Cited by
13References
4Claims
0Family size

Assignee

Inventors

Key dates

Filing dateNov 1, 2001
Grant dateSep 7, 2004
Priority date
Expiry dateNov 1, 2021

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH05B41/2928
  • WIPO fieldElectrical machinery, apparatus, energy
  • WIPO sectorElectrical engineering

Abstract

There is provided an improved method of lighting an ultra-high pressure discharge lamp in which a pair of electrodes are disposed confronting each other with a spacing of not more than 1.5 mm therebetween in an arc tube forming part of an envelope of quartz glass, the arc tube encapsulating mercury in an amount of 0.15 mg/mm3, the method including the steps of: reducing a lamp power supplied to the pair of electrodes to a degree such as not to stop arc discharge in a transition state from a lighting state to extinction; keeping the lamp power thus reduced for a predetermined time period; and shutting down the supply of current to the electrodes.

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