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:
May. 13, 1997
Filed:
Mar. 06, 1995
Applicant:
Inventor:
Robert A Dougherty, Ozona, FL (US);
Assignee:
A.C. Nielsen Company, Schaumburg, IL (US);
Primary Examiner:
Int. Cl.
CPC ...
H04N / ;
U.S. Cl.
CPC ...
348486 ; 348-1 ; 348473 ;
Abstract
An ancillary signal is injected into a program signal within the frequency band normally occupied by the program signal alone. The program signal includes a modulated carrier having a carrier frequency and a low energy density portion of the frequency band. The ancillary signal is selectively added at an injection frequency within the lower energy density portion of the frequency band so that the injection frequency is locked to the carrier frequency and to the frequency of a local oscillator.