| 摘要 |
PURPOSE:To decrease the quantization distortion with a simple constitution by adding the dither signal of the frequency larger than the 1/2 of a sampling frequency and smaller than (n-1/2) to a recording signal and executing the A/D converting with an (n)-fold oversampling. CONSTITUTION:An input recording signal is added with a dither signal from a generating circuit 17 in an adder circuit 12 and next, A/D-converted 13. When the final sampling frequency of an input signal is (f), the sampling at the time of the A/D conversion is executed for example by 2f. The dither signal is set between f/2-3f/2. An A/D converting output is inputted to a digital filter 14 driven by the clock of 2f, and the high area component of the input signal and the dither signal are removed. The output of the filter is thinned at one interval with a clock (f), sampled 15, made finally into the sampling data of the frequency (f), supplied to a rotary head through a signal processing circuit and recorded to a magnetic tape.
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