Medium storage device and medium rotation synchronization processing method for medium storage device

1 . A medium storage device comprising:

a head for either reading or writing data on a track of a storage medium where servo information, including servo synchronization marks, is written on one track with a predetermined interval;

an actuator for positioning said head on a desired track of said storage medium which is rotating;

a controller for controlling reading or writing data on said storage medium by said head at a timing synchronizing the rotation of said storage medium; and

a processing unit for correcting the synchronization timing of said controller from the interval of said servo synchronization marks detected by said controller,

wherein said processing unit judges whether or not the detected interval of the servo synchronization marks is within a predetermined range which is not occurred a frequency compensation to influent an error rate when reading, and corrects the synchronization timing of the controller based on the interval of the servo synchronization marks when the detected interval is judged within the predetermined range.

2 . The medium storage device according to claim 1 , wherein said processing unit judges whether or not a change amount between the interval of the servo synchronization mark is smaller than a change amount slice for judging within the predetermined range.

3 . The medium storage device according to claim 1 , wherein said processing unit processing unit judges whether or not a change amount between the interval of the servo synchronization mark is smaller than a absolute amount slice for judging within the predetermined range.

4 . The medium storage device according to claim 1 , wherein said processing unit processing unit judges whether or not the interval of the servo synchronization mark is within a correctable range.

5 . The medium storage device according to claim 1 , wherein said processing unit prohibits a least one of the write operation and the correction of the synchronous timing when the judging result indicates within the predetermined range.

6 . The medium storage device according to claim 1 , wherein said processing unit starts said synchronization timing correction processing according to a servo gate signal synchronizing the rotation of said storage medium.

7 . The medium storage device according to claim 6 , wherein said controller further comprises a counter for counting the servo synchronization mark detection time based on the clock of said clock source,

and said processing unit reads a count value of said counter according to a servo gate signal synchronizing the rotation of said storage medium, and executes said synchronization timing correction processing.

8 . The medium storage device according to claim 6 , wherein the timing generation circuit of said controller comprises:

a servo timing generation circuit for generating a servo timing signal from said clock;

a data timing generation circuit for generating a data timing signal from said clock; and

a write timing generation circuit for generating a write timing signal from said clock.

9 . The medium storage device according to claim 8 , wherein said controller further comprises a gate signal generation circuit for generating a servo gate signal, read gate signal and write gate signal according to said servo timing signal of said servo timing generation circuit.

10 . The medium storage device according to claim 8 , wherein said controller further comprises a detection circuit for outputting said servo information and read data from a read signal of said head according to said servo timing signal and said data timing signal.

11 . A medium rotation synchronization processing method for a medium storage device comprising the steps of:

writing or reading data on a track of a storage medium where servo information, including servo synchronization marks, is written on one track with a predetermined interval at a timing synchronizing the rotation of said storage medium with a head;

calculating a interval of the servo synchronization marks detected from a read signal of the head;

judging whether or not the calculated interval of the servo synchronization marks is within a predetermined range which is not occurred a frequency compensation to influent an error rate when reading; and

correcting the synchronization timing of the controller based on the interval of the servo synchronization marks when the detected interval is judged within the predetermined range.

12 . The medium rotation synchronization processing method for a medium storage device according to claim 11 , wherein said judgment step comprises a step of judging whether or not a change amount between the interval of the servo synchronization mark is smaller than a change amount slice for judging within the predetermined range.

13 . The medium rotation synchronization processing method for a medium storage device according to claim 11 , wherein said judgment step comprises a step of judging whether or not a change amount between the interval of the servo synchronization mark is smaller than a absolute amount slice for judging within the predetermined range.

14 . The medium rotation synchronization processing method for a medium storage device according to claim 11 , wherein said judgment step comprises a step of judging whether or not the interval of the servo synchronization mark is within a correctable range.

15 . The medium rotation synchronization processing method for a medium storage device according to claim 11 , further comprises a step of prohibits a least one of the write operation and the correction of the synchronous timing when the judging result indicates within the predetermined range.

16 . The medium rotation synchronization processing method for a medium storage device according to claim 11 , wherein said correction step further comprises a step of calculating the frequency correction amount of a clock in a timing generation circuit for creating a rotation synchronous timing signal from said clock of a clock generator.

17 . The medium rotation synchronization processing method for a medium storage device according to claim 16 , wherein said calculation step further comprises a step of calculating said interval of said servo synchronization mark by reading a count value of a counter for counting the servo synchronization mark detection time based on the clock of said clock source according to the servo gate signal synchronizing the rotation of said storage medium.

18 . The medium rotation synchronization processing method for a medium storage device according to claim 15 , wherein said correction step further comprises a step of performing frequency correction of said clock of a servo timing generation circuit for generating a servo timing signal from said clock, a data timing generation circuit for generating a data timing signal from said clock, and a write timing generation circuit for generating a write timing signal from said clock.

19 . The medium rotation synchronization processing method for a medium storage device according to claim 18 , further comprising a step of generating a servo gate signal, read gate signal and write gate signal according to said servo timing signal of said servo timing generation circuit.

20 . The medium rotation synchronization processing method for a medium storage device according to claim 18 , further comprising a step of detecting said servo information and read data from the read signal of said head according to said servo timing signal and said data timing signal.