发明公开
EP0518129A2 Method and apparatus for enhancing the security of a scrambled television signal
失效
Verfahren undGerätzur Sicherheitsverbesserung einesverschlüsseltenFernsehsignals。
- 专利标题: Method and apparatus for enhancing the security of a scrambled television signal
- 专利标题(中): Verfahren undGerätzur Sicherheitsverbesserung einesverschlüsseltenFernsehsignals。
-
申请号: EP92108925.6申请日: 1992-05-27
-
公开(公告)号: EP0518129A2公开(公告)日: 1992-12-16
- 发明人: Westerfer, Richard , Robbins, Clyde , Radice, Anthony M.
- 申请人: GENERAL INSTRUMENT CORPORATION OF DELAWARE
- 申请人地址: 181 West Madison Street Chicago, Illinois 60602 US
- 专利权人: GENERAL INSTRUMENT CORPORATION OF DELAWARE
- 当前专利权人: GENERAL INSTRUMENT CORPORATION OF DELAWARE
- 当前专利权人地址: 181 West Madison Street Chicago, Illinois 60602 US
- 代理机构: Hoeger, Stellrecht & Partner
- 优先权: US714673 19910613
- 主分类号: H04N7/167
- IPC分类号: H04N7/167
摘要:
The scrambling security of a sync suppressed television signal is enhanced by eliminating the fixed time relationship between the normal color burst component and synchronization information in successive lines of the television signal. Transmission of a first plurality of television lines is delayed to achieve a cumulative delay corresponding at least to the duration of a color burst component of the television signal. The transmission of a second plurality of television lines is subsequently accelerated to reduce the cumulative delay. By repeating the delaying and accelerating steps, the location of the color burst component is varied within the television signal over time. Derivation of a substitute horizontal synchronization pulse from the color burst component is thereby prevented.
公开/授权文献
信息查询