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:
Feb. 24, 1987
Filed:
Jan. 03, 1986
Clyde Robbins, Maple Glen, PA (US);
Daniel J Marz, Holland, PA (US);
General Instrument Corporation, New York, NY (US);
Abstract
An apparatus and method are provided for receiving and reproducing stereo television sound. A transmitted television signal is received that contains a first component comprising the sum of first and second stereophonically related audio signals and a second component comprising the difference between the first and second stereophonically related audio signals. The first and second components are converted to produce a first sound carrier centered at a first intermediate frequency and a second sound carrier centered at a second intermediate frequency. The first component is detected from the first sound carrier at the first intermediate frequency. The second component is detected from the second sound carrier at the second intermediate frequency. The detected first and second components are combined to produce a left channel audio output and a right channel audio output. By using a standard intercarrier detector for the first (L+R) component and an independent FM detector for the second (L-R) component, distortion caused by interfering harmonics of the television horizontal line frequency with vertical scan frequency sidebands falling within the (L-R) subchannel is prevented. A second audio program ('SAP') signal can also be recovered using the independent FM detector to avoid such distortion.