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:
Apr. 07, 1992
Filed:
Jul. 20, 1990
James J Gibson, Princeton, NJ (US);
Theodor M Wagner, Princeton, NJ (US);
Frank B Lang, Princeton Junction, NJ (US);
General Electric Company, Princeton, NJ (US);
Abstract
The present invention is directed to an improved solution to the problem of interference in the picture displayed by a standard NTSC receiver that results from a received television signal that includes a quadrature-amplitude modulated additional-information constituent passing through the Nyquist filter of the standard receiver (this additional-informaton constituent being intended for use only by wide-screen and/or extended-definition television receivers). This solution, in accordance with each of several different embodiments, employs means at the transmitter that includes frequency-dependent attenuation means operating at baseband frequencies to modify the relative amplitudes of each frequency component of the lower and upper sidebands of the transmitted television signal that defines the additional-information constituent in a manner to compensate for the attenuation characteristics of the Nyquist filter of a standard NTSC receiver.