Patent ID: 7644337

Claim:
An error correction device having an encoder and a decoder for correcting errors in data which is to be transmitted in a recording/reproducing system including a 1-bit-error-dominant recording medium, the error correction device characterized in that the encoder has an input unit that inputs unit length data to be recorded to the recording medium, a first encoding unit that subjects the unit length data to Reed Solomon encoding so as to generate a first RS parity, a second encoding unit that divides the data in which the first RS parity is adjacently connected to the unit length data into a predetermined number n of blocks and subjecting each of the blocks to cyclic Hamming encoding so as to generate Hamming parities, a third encoding unit that subjects data in which the Hamming parities are aligned in a row to Reed Solomon encoding so as to generate a second RS parity, and an output unit that outputs encoded data in which the first RS parity and the second RS parity are adjacently connected to the unit length data; and the decoder has an input unit that inputs the encoded data which is read from the recording medium and in which the first RS parity and the second RS parity are adjacently connected to the unit length data, a Hamming encoding unit that divides the data in which the first RS parity is adjacently connected to the unit length data into the predetermined number n of blocks and subjecting each of the blocks to cyclic Hamming encoding so as to generate Hamming parities, a first error correcting unit that subjects the data in which the Hamming parities are aligned in a row to Reed Solomon decoding together with the second RS parity so as to correct an error in the Hamming parities of the blocks, a second error correcting unit that subjects each of the blocks to cyclic Hamming decoding together with the error-corrected Hamming parity so as to correct a 1-bit error in the blocks, a third error correcting unit that subjects the data in which the 1-bit-error-corrected blocks are aligned to Reed Solomon decoding together with the first RS parity so as to correct an error in the blocks other than that of 1-bit, and an output unit that outputs the error-corrected unit length data.