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. 03, 1979
Filed:
Apr. 28, 1977
Marc Chomet, East Northport, NY (US);
Teleglobe Pay-TV System, Inc., Rego Park, NY (US);
Abstract
At the television transmitting end, the program audio signals to be encoded are limited to a range of 50 to 7,500 Hz. A 202 KHz signal is modulated by the so-limited audio signal and the resultant upper side-band is heterodyned against an upper side-band derived from modulating the 202 KHz signal by video horizontal drive signals. Only the lower side-band created by the heterodyning process is transmitted. At the receiver, the received single sideband signal is applied to a product detector whose other input receives the output of a horizontal drive oscillator operating in synchronism with the corresponding oscillator at the transmitter. The baseband audio signal is separated from the upper sideband signal at the product detector output by means of a low pass filter.