Patent ID: 6011765
Filing Date: 2000-01-04
Classification: G11B

Abstract:
A reproducing apparatus for reproducing a recording medium having recorded thereon, as a .SIGMA..DELTA. modulated 1-bit digital signal, an audio signal having a first band containing an audible range and a copying protection signal having a pre-set frequency in a second band separated from said first band and outside of the audible range of the audio signal, comprising:reproducing means for reproducing the 1-bit digital signal containing said audio signal and said copying protection signal from said recording medium;output means for outputting the 1-bit digital signal reproduced by said reproducing means;first extraction means for extracting the audio signal having the first band from the 1-bit digital signal reproduced by said reproducing means;second extraction means for extracting the copying protection signal contained in the second band from the 1-bit digital signal reproduced by said reproducing means; andcontrol means for inhibiting outputting of the 1-bit digital signal from said output means based on a presence of the copying protection signal extracted by said second extraction means, wherein said second extraction means includes:filtering means for extracting the copying protection signal having the pre-set frequency contained in said second band from the 1-bit digital signal; andcomparator means for comparing a level of the copying protection signal extracted by said filtering means to a reference level, wherein when said comparator means finds that the level of the copying protection signal extracted by said filtering means is larger than said reference level said control means inhibits outputting of the 1-bit digital signal.