| 摘要 |
<p>PROBLEM TO BE SOLVED: To improve the image quality in a circuit that conducts infield interpolation for a MUSE demodulation signal or the like. SOLUTION: The decoder is provided with a 1st filter 10 for a Y signal and a 2nd filter 20 for color difference signals, and a switch S is thrown to any position to limit a frequency band according to the frequency characteristic set by the selected filter in the two filters 10, 20 for a received MUSE demodulation signal. Furthermore, the switch S is thrown by a signal fed from a control circuit (not shown) at a timing of a Y signal component or a timing of a color difference signal component. The characteristic of the 2nd filter 20 from which the color difference signal is outputted is selected so that vertical high frequency pass components and horizontal low frequency, pass components are sufficiently suppressed to prevent a loopback disturbing signal. The characteristic of the 1st filter 10 from which the Y signal component is outputted is selected in such a way that vertical low frequency pass components and horizontal high frequency pass component are not especially suppressed similarly to the case with a characteristic of a conventional filter, since the vertical sampling frequency of the Y signal component is selected higher (twice) in comparison with that of the color difference signal, the characteristic of this filter is not a problem.</p> |
