Apparatus for scrambling a television signal

摘要

An apparatus for scrambling or encoding a television signal by inverting the latter signal in accordance with a control signal having a predetermined code pattern comprises a detector circuit for detecting a change in a picture scene of the television signal and generating an identification signal in response to detection of the scene change and code generator for generating a key code signal of specific pattern which indicates a particular program of the television signal. According to this invention, the control signal is formed in response to both the identification signal and the key code signal.