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:
Jan. 01, 1985
Filed:
Jun. 15, 1982
Peter M Flamm, Freiburg, DE;
ITT Industries, Inc., New York, NY (US);
Abstract
To digitally synchronize the chrominance-subcarrier oscillator in the form of a phase-locked loop with the color burst contained in the composite color signal, suitable digital subcircuits are provided. During the keying pulse, the digital R-Y and B-Y color-difference signals are accumulated line by line. The corresponding R-Y value is then added to a desired phase value or a tint-control value, and for deviations from the burst phase between +90.degree. and -90.degree., the sum signal, after being limited if necessary, is applied to a digital-to-analog converter, filtered in a low-pass filter, and then used to control the chrominance-subcarrier oscillator. If the phase deviations lie between +90.degree. and +180.degree. or -90.degree. and -180.degree., the digital-to-analog converter is constantly fed with the upper or the lower limit value, respectively, via a switching stage. The latter has three switch positions, one for direct transfer and one for each of the two limit values, with the sign bit of the accumulated R-Y or B-Y value effecting the appropriate selection.