Patent ID: 7365657

Claim:
A data identification method for identifying, from within a readout signal inputted from a recording medium on which data are recorded using a recording modulation code wherein, from among n bits which form a codeword, m bits have a value of “1” while the remaining n-m bits have another value of “0”, the data, n and m being integers, comprising: a first step of delimiting the readout signal in a unit of a codeword, checking the amplitude of each bit of an n-bit codeword obtained by the delimiting and applying numbers from #1 to #n to the bits in a descending order of the amplitude; a second step of setting an n-bit codeword wherein m bits of the order numbers from #1 to #m are set to “1” and the other n-m bits of the order numbers from #(m+1) to #(n-m) are set to “0” as a first candidate for an identification result; a third step of comparing the candidate for an identification result with a table of recording modulation codes to decide whether or not the candidate for an identification result is included in the table of recording modulation codes and outputting, if the candidate for an identification result is included as a recording modulation code in the table of recording modulation codes, the candidate for an identification result as an identification result; and a fourth step of selecting, if the candidate for an identification result is not included in the table of recording modulation codes at the third step, a next candidate for an identification result in an order determined in advance; the third and fourth steps being repeated until an identification result included in the table of recording modulation codes is obtained at the third step.