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:
Sep. 09, 1986
Filed:
May. 07, 1984
Gregory A Williams, Elk Grove Village, IL (US);
Zenith Electronics Corporation, Glenview, IL (US);
Abstract
A cable television system capable of decoding signals encoded in two different formats, A and B. Format A is identified by digital data on horizontal lines 10-13 in the vertical blanking interval and format B by digital data on horizontal lines 14-17 in the vertical blanking interval. Logic circuitry receives the vertical blanking interval data and supplies one pulse marking the beginning of the vertical blanking interval and an identifier pulse derived from digital data on horizontal lines 13 or 17. A format mode control switch includes a monostable timing circuit producing an output responsive to the vertical blanking interval pulse for a period terminating at approximately horizontal line 14. The timing circuit output is supplied along with the identifier pulse to the inputs of a flipflop for determining which of the decoders A and B is to be energized.