| 摘要 |
PURPOSE:To eliminate effectively a noise by detecting fluctuation of a data from a difference signal among three consecutive sampling data and outputting an input signal via a nonlinear filter when the result of detection is a fixed value or above. CONSTITUTION:A key signal fed to an input terminal 31 is applied to a nonlinear filter 32 and also to a selector 33 and a slope deciding circuit 34. The slope deciding circuit 34 discriminates a signal from a noise in horizontal direction and if the signal is noise, an output signal of the nonlinear filter 32 is selected and when a signal, the signal not through the nonlinear filter 32 being selected by controlling the selector 33. Moreover, an output signal of the selector 33 is applied to a nonlinear filter 42 eliminating noise in vertical direction, a selector 43 and a polarity deciding circuit 44, and the selector 43 is controlled by the decision output of the polarity deciding circuit 44 and a key signal from which noise is eliminated is extracted at an output terminal 48. |
