| 摘要 |
PURPOSE:To obtain a separated brightness signal whose signal components of frequencies between the frequencies integer-times of the half of the horizontal frequency within a prescribed band is emphasized by constituting the circuitry in a simple constitution requiring no special delay circuits other than a delay circuit for the signal- separation. CONSTITUTION:An input video signal Vi is supplied to a delay circuit 21 and delayed for two times of horizontal frequency. An output signal from the delay circuit 21 is subtracted from the input video signal Vi, an output signal from an subtraction circuit 22 is supplied to an attenuator circuit 23 where it is attenuated to the half, and an output signal from the attenuator circuit 23 is conducted to an output terminal 20c. Also, the output signal from the attenuator circuit 23 is subtracted from the input video signal Vi, and an output signal from a substraction circuit 24 is conducted to an output terminal 20y. Therefore, assuming the horizontal frequency of the input video signal Vi to be fH and the subc arrier wave frequency of the same to be fsc, the frequency characteristic between a video signal input terminal 10 and the output terminal 20c forms troughs of minimum gain at the frequencies integer-times of the half of the horizontal frequency through entire carrier color signal band and the lower side band.
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