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:
Feb. 24, 1987
Filed:
Aug. 06, 1984
Arthur Heller, Eichenried, DE;
Friedrich Gierlinger, Markt Indersdorf, DE;
Alfred Schaumberger, Olching, DE;
U.S. Philips Corporation, New York, NY (US);
Abstract
A method of producing a modulated chrominance signal with suppressed carrier. A square-wave carrier signal and a color information signal in the form of a sequence of digitally encoded amplitude values are applied to a modulator arrangement. The clock frequency for the amplitude values is an integral multiple of the color carrier frequency and is phase-locked thereto. Each bit of the amplitude values is inverted during one half cycle of the carrier and not inverted in the subsequent half cycle. A first and a second value, respectively are added to the values obtained thus, these first and second values being calculated such that also for input and/or output signal values which are located at a distance from the drive mean values at the input and output ends a total carrier suppression is achieved for the desired input signal level. The modulated analog chrominance signal is available after digital-to-analog conversion.