External input signal processing circuit for a television receiver with a video tape recorder for the purpose of viewing copy-protected video signals

An external input signal processing circuit, for a television receiver with a video tape recorder, the video tape recorder having recording and reproducing functions, said external input signal processing circuit comprising:

• an automatic gain control circuit having an input terminal connected to an external input terminal of the video tape recorder and an output terminal connected to a video signal recording circuit for recording a video signal on a recording medium;
• a video signal reproducing circuit for reproducing a video signal recorded on said recording medium;
• an internal/external viewing changeover switch having one input terminal connected to receive a video signal from said video signal reproducing circuit, another input terminal connected to between said input terminal of said automatic gain control circuit and said external input terminal, and a common terminal connected to a television signal processing circuit to permit viewing of a signal reproduced by said reproducing circuit or input terminal;
• and
• a switch circuit for controlling said internal/external viewing changeover switch so that the one input terminal and the common terminal of said internal/external viewing changeover switch are connected to each other when the video tape recorder is in a recording mode.