Patent ID: 7738332
Filing Date: 2010-06-15
Classification: G11B

Abstract:
1. An information reproduction method comprising the processes of: recording data on an optical disk; and changing the judgment standard of the quality of said recorded data in accordance with a reproduction speed when said recorded data is reproduced; in which: said process of recording data is a process of recording a data block on an optical disk medium with a run length limited code after an error correction code is added to the data; and said process of changing the judgment standard comprises the processes of: (1) obtaining a regenerative signal by optically reproducing said recorded data block; (2) obtaining a binarized data signal by binarizing said regenerative signal; (3) obtaining a byte data string by decoding said binarized data signal with said run length limited code; (4) after reconfiguring said byte data string into error correction frames, applying error correction processing with a Reed-Solomon code, and counting a corrected byte number N (5) counting the total number of the error correction frames wherein said corrected byte number N (6) judging that the quality of said data block is insufficient when said error frame number N wherein the quality of the recorded data is judged in accordance with a reproduction speed by changing at least one of said first and second threshold values in accordance with the reproduction speed.