Patent · US Expired

Circuit arrangement for detecting the amount of deposited electrode material on the wall of a lamp vessel

US5689156A · kind A · utility

0Cited by

2References

18Claims

0Family size

Assignee

U.S. Philips Corporation · US

Inventors

Gunther Hans Derra · Aachen, DE
Hanns E. Fischer · Stolberg, DE
Hans G. Ganser · Stolberg, DE
Holger Monch · Vaals, NL

Key dates

Filing date	Jan 5, 1996
Grant date	Nov 18, 1997
Priority date	—
Expiry date	Jan 5, 2016

Classification

Technology area (CPC H)Electricity
CPC primaryH01J61/56
WIPO fieldElectrical machinery, apparatus, energy
WIPO sectorElectrical engineering

Abstract

The invention relates to a measuring circuit for detecting the amount of deposited electrode material on the wall of a lamp vessel of a discharge lamp by measuring the power of infrared radiation within a specific wavelength range, comprising a detector for generating an electrical signal constituting a measure for the power of the infrared light in said specific wave length range. According to the invention the measuring is done in a time lapse starting after a predetermined time interval following the extinguishing of the discharge lamp. An increased accuracy of the measurement is thereby realized.

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