The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 18, 1997
Filed:
Jan. 05, 1996
Gunther H Derra, Aachen, DE;
Hanns E Fischer, Stolberg, DE;
Hans G Ganser, Stolberg, DE;
Holger Monch, Vaals, NL;
U.S. Philips Corporation, New York, NY (US);
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.