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. 09, 1999
Filed:
Aug. 07, 1998
David Ross Jackson, Indianapolis, IN (US);
Thomson Consumer Electronics, Inc., Indianapolis, IN (US);
Abstract
A high-voltage power supply of a video display apparatus provides an ultor voltage and a focus voltage to a cathode ray tube. A low-voltage power supply provides a variable voltage to a primary winding of a flyback transformer of the high-voltage power supply. The magnitude of the variable voltage is responsive to first and second feedback signals provided by first and second negative feedback paths. The first feedback signal is derived from the ultor voltage and is used to regulate the ultor voltage. The second feedback signal is provided by the low-voltage power supply via a path that bypasses the high-voltage power supply, and is summed with the first feedback signal to ensure that the focus voltage remains at or above a predetermined minimum voltage.