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:
Jun. 03, 2003
Filed:
Jan. 09, 2002
Dirk Killat, Kircheim, DE;
Dialog Semiconductor GmbH, Kirchheim/Teck-Nabern, DE;
Abstract
A method to control the illumination intensity of a gas discharge lamp is achieved. The method comprises, first, converting an analog lamp illumination signal into a digital lamp illumination signal. The analog lamp illumination signal is a function of the illumination intensity of a gas discharge lamp. Second, digital target signal is subtracted from the digital lamp illumination signal to create a digital error signal. Third, a digital frequency set point is adjusted from a current value to a new value based on the digital error signal. The digital frequency set point is a high resolution digital value. Fourth, the current value and the new value are averaged by a digital delta sigma modulator to create a smoothed frequency set point. The smoothed frequency set point is a medium resolution value. Finally, an oscillating voltage signal is generated with a drive frequency based on the smoothed frequency set point. The drive frequency determines the illumination intensity of the gas discharge lamp.