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. 25, 2003
Filed:
Jul. 30, 2001
David A. Cammack, Scarborough, NY (US);
Koninklijke Philips Electronics N.V., Eindhoven, NL;
Abstract
A gas discharge lamp is driven by a bridge circuit which produces a pulse voltage signal. The bridge circuit is pulse width modulated at an operational frequency, and has a power input for receiving power from a power source, and a control signal input for receiving a control signal that effects sweeping of the operational frequency and generation of the pulse voltage signal. The system further includes a controller for controlling the bridge circuit, the controller comprising circuitry for (i) generating a signal comprising a frequency swept signal that is amplitude modulated by a fixed frequency signal, the highest frequency of the frequency swept signal being lower than the operational frequency, and the signal generated by the controller being inputted into the control signal input of the bridge circuit, and (ii) periodically sweeping the operational frequency of the bridge circuit. The system further includes a filter circuit for filtering the pulse voltage signal.