US005754650A United States Patent (19) 11 Patent Number: 5,754,650 Katznelson 45 Date of Patent: May 19, 1998

54 SIMULTANEOUS MULTICHANNEL OTHER PUBLICATIONS TELEVISION ACCESS CONTROL SYSTEM AND METHOD "Instruction Manual." MX-MS Scrambler, Magnavox 75) Inventor: Ron D. Katznelson, San Diego, Calif. CATV Systems, Inc. 1979. Ostuni, Joseph. "Reference Manual. Pay TV." Magnavox 73) Assignee: Multichannel Communication CATV Systems, Inc. 1978. Sciences, Inc., San Diego, Calif. "Terminal Products." Magnavox CATV Systems, Inc. 1979. (21) Appl. No.: 433,135 22 Filed: May 3, 1995 Primary Examiner-Gilberto Barron, Jr. Attorney, Agent, or Firm-Irell & Manella LLP Related U.S. Application Data 57 ABSTRACT 63 Continuation of Ser. No. 233,212, Apr. 25, 1994, Pat No. 5,430,799, which is a continuation of Ser. No. 818,752, Jan. A multichannel television access control system is disclosed 8, 1992, abandoned. wherein processing of the broadband signal is performed by (51) int. C. ... H04N 7/171 gated coherent RF injection on a plurality of channels. 52) U.S. Cl...... 380/15; 380/12;380/34; thereby effecting selective descrambling of an arbitrary 380/20 subset of channels in a channel group. The system provides 58) Field of Search ...... 380/7, 10, 12. for a closed loop injection signal phasor control so as to 380/13, 15, 34, 20 maintain substantially constant relationship between the television signals and the injected signals. The combined 56) References Cited signals are supplied to subscribers enabling the use of their cable ready equipment. U.S. PATENT DOCUMENTS 5,319,709 6/1994 Raiser et al. . 35 Claims, 18 Drawing Sheets

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