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Color picture-in-picture television receiver

  • US 4,278,993 A
  • Filed: 11/13/1979
  • Issued: 07/14/1981
  • Est. Priority Date: 11/20/1978
  • Status: Expired due to Term
First Claim
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1. A system for inserting a reduced picture of a first channel broadcast into a picture of a second channel broadcast on a single screen in a picture-in-picture television receiver, comprising:

  • a first tuner, I.F., video detector, and decoder chain for producing video signals of said first channel broadcast;

    a second tuner, I.F., video detector, and decoder chain for producing video signals of said second channel broadcast;

    a first group of three memories connected to the first chain for memorizing R, G and B signals obtained from a first field of video signals of said first channel broadcast;

    a second group of three memories connected to the first chain for memorizing R, G and B signals obtained from a second field of the video signals of said first channel broadcast;

    control means for writing in one of said R, G and B signals into a corresponding one of said first group of three memories and the remaining two of said R, G and B signals into a corresponding remaining two of said first group of three memories during said first field by first and second trains of writing pulses, respectively, the second train of pulses being opposite in phase to the first train;

    during said second field said control means writing in said one of the R, G and B signals into one of the second group of three memories and said remaining two of the R, G and B signals being written into a corresponding remaining two of said second group of three memories during the second field by said second train and said first train, respectively.

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