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:
Jul. 22, 1986
Filed:
Nov. 21, 1983
Pieter Fockens, Glenview, IL (US);
Zenith Electronics Corporation, Glenview, IL (US);
Abstract
The frequency response of an intermediate frequency filter for an intercarrier sound television receiver is modified to provide a substantially constant gain response portion over a predetermined range of frequencies centered about the 45.75 MHz intermediate frequency picture carrier. Picture carrier phase modulation induced by the Nyquist slope of the conventional intermediate frequency response is thereby eliminated over the predetermined frequency range reducing audio 'buzz' by decreasing the phase modulation transferred to the 4.5 MHz intercarrier sound signal by the intermediate frequency picture carrier. In a preferred embodiment, the modified intermediate frequency response is established by a surface acoustic wave filter.