Patent ID: 8102744

Claim:
A recording medium playback device, comprising: a first binarization portion that, using a partial response maximum likelihood decoding processing, binarizes a signal that is read from data that is recorded in a recording medium; a second binarization portion that binarizes the signal based on a magnitude relationship to a specified threshold value; and a frame synchronization signal detection portion that detects a frame synchronization signal in data that have been processed by the first binarization portion and the second binarization portion, the frame synchronization signal detection portion including a first frame synchronization signal detection portion that detects a synchronization pattern in a first binarized data string that is produced by the first binarization portion, and determines by a pattern matching whether the first binarized data string is the synchronization pattern and whether the first binarized data string is a detection pattern, and a second frame synchronization signal detection portion that detects a synchronization pattern in a second binarized data string that is produced by the second binarization portion, wherein if the synchronization pattern is not detected by the first frame synchronization signal detection portion, a signal that is derived from the synchronization pattern that is detected by the second frame synchronization signal detection portion is used as the frame synchronization signal.