| 摘要 |
PURPOSE:To eliminate the impulsive noises without generating signal distortions, by excluding a period including the impulsive noises of an input signal and then interpolating the excluded period with signal levels before and after the excluded period. CONSTITUTION:The gate pulse given from a detecting circuit (not shown in the figure) which detects the impulsive noises controls switches S1-S4. When no impulsive noise exists, an input signal (f) is delivered via a delay circuit 12 having the same time as the gate pulse width, a buffer amplifier 17 and the switch S1. If the input signal contains impulsive noises, the gate pulse turns off the switches S1 and S3 to prevent the output of the signal (f) to an output terminal 18 for a signal period containing the impulsive noises and holds the difference of signal levels before and after a gate pulse period at a capacitor C2. At the same time, the switches S4 and S2 are turned on, and an interpolation circuit consisting of an arithmetic amplifier 14 and a buffer amplifier 15 charges and discharges the signal held at the capacitor C2 to a capacitor C1 and then delivers the interpolated signal to the terminal 18. The switch S2 and a buffer amplifier 16 smooth the joint of signals after the end of interpolation. |
