专利名称：CATV system transmitting a scrambled
television signal
发明人：Akira Ideno申请号：US07/448442申请日：19891211公开号：US04953208A公开日：19900828
摘要：A method of scrambling a television signal is provided in which, during ahorizontal blanking interval and during a vertical blanking interval, a video signal iscompressed and a key signal containing information concerning the compression issuperimposed on an audio signal in the horizontal blanking period. The method ischaracterized by superimposing a pseudo-key signal on an audio signal in the verticalblanking interval, making the key signal contain information concerning the position of avertical blanking interval, and fixing a video signal in a predetermined number ofhorizontal scanning periods before a vertical synchronizing signal portion in the verticalblanking interval at a constant level while eliminating color bursts in a predeterminednumber of horizontal scanning periods before and after the vertical synchronizing signalportion in the vertical blanking interval. In this way, unauthorized users are prohibitedfrom receiving the signal, and unauthorized access is made difficult.
申请人：PIONEER ELECTRONIC CORPORATION
代理机构：Sughrue, Mion, Zinn, Macpeak & Seas
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