| 摘要 |
PURPOSE:To improve the packing density on a medium and, at the same time, to increase the line speed, by simultaneously recording digital signals by using plural modulating systems and separating their reproduced signals into a low frequency band and high frequency band, and then, demodulating the low frequency component of the high frequency band after correction. CONSTITUTION:Inputted analog signals are supplied to modulator circuits 6 and 7 through an LPF2, sample and hold circuit 3, AD converter 4, and encoder 5. At the circuit 6 a modulating system in which the distribution of frequency spectrum is concentrated in the low frequency band is used and at the circuit 7 another modulating system in which the frequency spectrum distribution is concentrated in the high frequency band is used. Each modulated output is added 8 to each other and supplied to rotary heads 15A and 15B through switching circuits 9, 14A and 14B, and then, recorded on a tape 16. Reproduced outputs from the heads 15A and 15B are alternately switched through the circuits 14A and 14B and a switching circuit 18 and supplied to a demodulator circuit 21 through an LPF19 and HPF20 and to another demodulator circuit 23 through a low-band correcting circuit 22. Demodulated outputs of each demodulator circuit 21 and 23 are supplied to a decoder 24. |
