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. 13, 1988
Filed:
Nov. 06, 1986
Thomas F Martin, Richardson, TX (US);
John P Fullingim, Dallas, TX (US);
General Instrument Corporation, New York, NY (US);
Abstract
A cable television channel selector/descrambler enables the full capabilities of a cable-ready video appliance (e.g., television set or VCR) to be used in conjunction with a cable television system providing unscrambled channels and scrambled premium channels. A broadband cable signal containing a plurality of television signal channels having different frequencies is passed through a filter to produce a modified cable signal having one of the signal channels removed therefrom. The broadband cable signal is input to a tuner for selectively tuning only to scrambled signal channels contained in the broadband cable signal. The tuner is tuned to a scrambled signal channel to be viewed by stepping through the scrambled signal channels accessible by the tuner until the desired signal channel is reached. A scrambled signal tuned by the tuner is descrambled and remodulated to convert it to the frequency of the signal channel removed by the filter in producing the modified cable signal. The re-modulated descrambled signal is combined with the modified cable signal to form a composite signal for input to a video appliance. The composite signal contains all of the original unscrambled channels together with the selected premium channel which has been descrambled.