| 摘要 |
PURPOSE:To improve a waveform characteristic, a frequency characteristic, and a phase characteristic at a large-amplitude level by offsetting the low-pass characteristic at the large-amplitude level in the titled filter which eliminates small-amplitude level components in high frequency band. CONSTITUTION:When a reproduced brightness signal is supplied to an input terminal 1, its high frequency band is taken out by high-pass filter (HPF) 3 and 12 having cut-off frequencies equal to each other. From the output of the HDF 3, the small-amplitude-level components in the high-frequency band i.e. noise components are taken out by a limiter 4, and inputted to a subtractor 11. Meanwhile, the output of the HPF 12 inputted to the subtractor 11 through a level setting circuit 13. And the output of the subtractor 11 goes through a low-pass filter 5 and a variable attenuator 6, and is inputted to a subtractor 2, where the noise components are subtracted from the brightness signal supplied to the input terminal 1. By properly setting the gain of a level setting circuit 13, the low-pass characteristic at large amplitude can be offset.
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