A password (PW) restriction apparatus for cable television (CT) channels having a downward receiving signal controller (DRSC) for receiving a downward receiving signal output from a cable television transmitting/receiving portion (CTTRP) and transmitting digital signals to control...http://www.google.fr/patents/US5764281?utm_source=gb-gplus-shareBrevet US5764281 - Password restriction of cable television channel using key input controller
Password restriction of cable television channel using key input controller ...
