Patent ID: 7209641

Claim:
A decoder for decoding reproduced data including preamble data, which is read from a certain recording section of a disc medium and to which a first synchronization pattern is added, and information data, which follows the preamble data and to which a second synchronization pattern is added, the decoder comprising: a memory for storing a first comparison pattern corresponding to the first synchronization pattern, a second comparison pattern corresponding to the preamble data, and a third comparison pattern corresponding to the second synchronization pattern; a comparison circuit connected to the memory to compare the first synchronization pattern, the preamble data, and the second synchronization pattern respectively with the first to third comparison patterns; a determination circuit connected to the comparison circuit to generate a start trigger signal instructing to start decoding when at least two of the first synchronization pattern, the preamble data, and the second synchronization pattern match the corresponding comparison pattern; and a decoding circuit connected to the determination circuit to start error correction of the reproduced data in response to the start trigger signal.