| 摘要 |
PURPOSE:To simplify the constitution of both a pre-emphasis circuit and a de-emphasis circuit which improve the S/N by converting a signal which performs the transmission or the record/reproduction into a signal that has the desired amplitude characteristic together with the linear phase characteristic. CONSTITUTION:A basic circuit 10 needed for constitution of a pre-emphasis circuit or a de-emphasis circuit consists of an impedance circuit Z11, an admittance circuit Y12, and a resistor R1 13. The signal processing is performed with a 1st transmission function with which an input signal is approximated by a function serving as an equation I within a prescribed frequency band with an angle frequency of the input signal shown by omega, a complex angle frequency shown by S, the constants having the time units shown by (S=jomega) and T, a real number of >=0 shown by K, and an integer shown by (m) respectively. Then the signals are continuously processed with a 2nd transmission function with which the signal processing output of the 1st transmission function is approximated by a function serving as an equation II. The value of K is changed with both the 1st and 2nd transmission functions in response to the level of a high band component of the input signal. Thus both the pre-emphasis and de-emphasis circuits are obtained for improvement of the signal S/N. |
