The generation of a pseudo-lock is prevented in a JFB offset compensator whose use has been conventionally limited due to a tendency to generate the pseudo-lock, and performance degradation of a PLL and a Viterbi decoder is suppressed. A means for monitoring an offset of a read signal is provided independently from the JFB offset compensator. With this configuration, the generation or a possibility of the generation of the pseudo-lock can be detected to reset an integrator. In order to reduce the influence of a large sporadic offset triggering the pseudo-lock, there may also be provided a limitter for limiting the absolute value of an offset signal inputted to the integrator or a limitter for limiting the absolute value of an offset compensation signal.

Title
Offset compensator and optical disc drive using the same
Application Number
EP20080019953 20081114
Publication Number
2061031 (A2)
Application Date
November 14, 2008
Publication Date
May 20, 2009
Inventor
Kikugawa Atsushi
JP
Assignee
Hitachi LG Data Storage
JP
Hitachi
JP
IPC
G11B20/14
G11B 20/14
G11B20/10
G11B 20/10
G11B20/14
G11B 20/14
G11B20/10
G11B 20/10
View Original Source Download PDF