ELECTRONIC COMMUNICATION APPARATUS FOR SELECTIVELY DISTRIBUTING SUPPLEMENTARY PRIVATE PROGRAMMING

• US 3,730,980 A
• Filed: 05/24/1971
• Issued: 05/01/1973
• Est. Priority Date: 05/24/1971
• Status: Expired due to Term

• Current Assignee: Donald Kirk Jr
• Original Assignee: Donald Kirk Jr
• Inventors: Kirk, Donald Jr.
• Primary Examiner(s): Borchelt, Benjamin A.
• Assistant Examiner(s): Buczinski, S. C.
• Application Number:
  US05/146,086
• Time in Patent Office: 708 Days
• Field of Search: 178/5.1 325/32 179/1.5R,1.5FS
• US Class Current: 380/220
• CPC Class Codes: H04K 1/04 by frequency scrambling, i.e. by transposing or inverting parts of the frequency band or by inverting the whole band
• CPC Class Codes: H04N 21/2543 Billing , e.g. for subscription services payment schemes, architectures or protocols G06Q20/00; e-commerce G06Q30/00; arrangements for billing for the use of broadcast information or broadcast-related information H04H60/21
• CPC Class Codes: H04N 21/812 involving advertisement data advertising per se G06Q30/02
• CPC Class Codes: H04N 7/167 Systems rendering the television signal unintelligible and subsequently intelligible

Abstract

Private programming information, e.g., television programs provided for a community antenna television signal distribution system (CATV) to supplement those programs received from local commercial television stations, are propagated over a common cable medium, and are selectively recoverable only by participating subscribers. Two private programs are formed with inverted modulation spectra in the mid-band channel frequency spacing. One or both programs are recovered at participating subscriber stations by heterodyne converters which re-invert the encripted signals, shifting one or both signal spectra to otherwise unoccupied commercial channels for recovery by a conventional television receiver.

Claims

1. In combination in a television communication system for propagating private supplementary television signals;

means for supplying at least one private program having an inverted modulation spectrum with a sound carrier lower in frequency than the picture carrier and a vestigial upper video side band, means for distributing said private television program, and converter means coupled to said distributing means for recovering said private programs, said converter means includIng heterodyning means for reversing the modulation spectrum of said private program distributed by said distribution means, said heterodyning means including mixer means and local oscillator means for providing an output signal higher in frequency than the highest frequency of said distributed private television programs for inverting the modulation spectrum of said private programs and for shifting the inverted spectrum in frequency, wherein said private program supplying means including means for supplying two private programs, each having an inverted modulation spectrum and a vestigial upper video side band, said programs having all frequencies components thereof in the range 88-174 mc, said two spectra having corresponding parts thereof separated by the interchannel frequency difference between two commercial television channels.

2. A combination as in claim 1 wherein said local oscillator includes means for generating an output frequency for shifting only one of said programs to a conventional television frequency channel.

3. A combination as in claim 1, wherein said local oscillator includes means for generating an output frequency for shifting the frequency spectra of both of said signals to that of commercial television frequency channels.

4. A combination as in claim 1, said two spectra having corresponding parts thereof separated by 22 megacycles.