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:
Oct. 24, 1995
Filed:
Aug. 20, 1993
Allen L Limberg, Ringoes, NJ (US);
Chandrakant B Patel, Hopewell, NJ (US);
Tianmin Liu, Lawrenceville, NJ (US);
Samsung Electronics Co., Ltd., Kyungki, KR;
Abstract
A relatively low power phase-shift-keyed (PSK) subcarrier encoding digital information is admixed with composite video signal. The PSK subcarrier is at an odd multiple of half the scan line frequency of the composite video signal, and the symbol rate is at a multiple of the scan line frequency. The PSK subcarrier modulates the amplitude of a suppressed carrier which is the same frequency as the video carrier for the composite video signal and preferably is in quadrature phasing therewith. To reduce evidence of the PSK subcarrier in television picture generated from that composite video signal, the PSK subcarrier is interrupted after each of periods of one frame duration and repeated in anti-phase during the next period of one frame duration. This also provides a basis for separating the PSK subcarrier from static luminance signal components by bandpass frame-comb filtering. Preferably, in the scan lines of consecutive pairs of scan lines, the PSK subcarrier is repeated with phase reversal of the subcarrier between scan lines, and the chroma subcarrier is repeated. This provides a basis for separating PSK subcarrier from chroma subcarrier by lowpass line-comb filtering.