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. 22, 1979
Filed:
May. 12, 1977
Applicant:
Inventors:
Melvin C Hendrickson, Elmhurst, IL (US);
Richard G Merrell, Darien, IL (US);
Assignee:
Zenith Radio Corporation, Glenview, IL (US);
Attorneys:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H04B / ; H04N / ;
U.S. Cl.
CPC ...
325464 ; 325468 ; 358191 ;
Abstract
A television window tuning system has duty cycle adjustment means for selectively varying the duty cycle of the tuner associated local oscillator signal. Increasing the duty cycle of the local oscillator signal effectively shifts the tuning window in frequency space in one direction while decreasing the duty cycle shifts the window in the opposite direction. In one embodiment of the invention, the duty cycle adjustment means is set for producing a 0% duty cycle oscillator signal for deriving a tuning window particularly adaptable for use with conventional AFC systems.