Patent ID: 6307595
Filing Date: 2001-10-23
Classification: H04L,H04N

Abstract:
An NTSC/DTV television signal reception apparatus for receiving transmitted television signals of NTSC type and of at least first and second digital types, said television signal reception apparatus comprising:a receiver portion for supplying a first baseband signal responsive to an NTSC television signal received during first times, which receiver portion includes circuitry for generating a 4.5 MHz intercarrier sound intermediate-frequency signal;a receiver portion for supplying a second baseband signal responsive to a digital television signal of said first digital type received during second times;a receiver portion for supplying a third baseband signal responsive to a digital television signal of said second digital type received during third times;a carrier amplitude detector for responding to a pronounced 4.5 MHz intercarrier sound intermediate-frequency signal being continuously generated to supply an indication of the reception of an NTSC analog TV signal;circuitry for selectively processing said second baseband signal, said processing of said second baseband signal normally being enabled but being subject to disablement, said processing of said second baseband signal being disabled in response to said carrier amplitude detector supplying said indication of the reception of an NTSC analog TV signal;circuitry for selectively processing said third baseband signal, wherein said television signals of said second digital type contain a pilot carrier of specific frequency that said television signals of said first digital type do not; anda pilot carrier detector for detecting the reception of said pilot carrier of specific frequency to supply indication of the reception of a television signal of said second digital type and for otherwise withholding said indication of the reception of a television signal of said second digital type, wherein said circuitry for selectively processing said second baseband signal is of a type that is disabled in response to said pilot carrier detector supplying said indication of the reception of said pilot carrier of specific frequency, and said circuitry for selectively processing said third baseband signal is of a type that is enabled only in response to said pilot carrier detector supplying said indication of the reception of said pilot carrier of specific frequency.