Circuit for simultaneously generating the sounds of both main picture and sub-picture for a picture-in-picture system of VTR

Claim 1

In a VTR having a picture-in-picture system, a circuit for simultaneously generating the sounds of both main picture and sub-picture comprising: first switching means for selecting a given voltage through a power source terminal or delay regenerating signal through a delay regenerating signal input terminal according to a selecting signal from a main picture/sub-picture selecting signal input terminal; hi-fi sound receiving means for amplifying and demodulating the hi-fi regenerating signal when the selected signal of said first switching means indicates said delay regenerating signal or for eliminating noises of an EE (Electronic and Electronic) signal from an EE input terminal when the selected signal of said first switching means indicates said given voltage; second switching means for selecting said given voltage through said power source terminal or said delay regenerating signal through said delay regenerating signal input terminal according to said selecting signal; linear sound receiving means for receiving a linear regenerating signal or an EE signal through a line input terminal according to the selection performed by said first switching means; third switching means for selecting the output signal of said hi-fi sound receiving means through said first switching means or the output signal of said linear sound receiving means through said second switching means according to the selecting signal from a main sound/sub-sound selecting signal input terminal; adder means for adding the output signal of said hi-fi sound receiving means through said first switching means to product an output; and amplify means for amplifying the signal input through said third switching means to produce a second output.