Control apparatus, storage apparatus, and head control method

Abstract

The present invention has been made to provide a control apparatus, a storage apparatus, and a head control method capable of preventing a use of a correction value that has improperly been read out.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing a configuration example of a disk apparatus according to an embodiment of the present invention;

FIG. 2 is a block diagram showing a configuration example of a servo frame according to the present embodiment;

FIG. 3 is a waveform showing an example of the result of readout operation of a servo frame according to the present embodiment;

FIG. 4 is a waveform showing an example of the result of readout operation of PostCode according to the present embodiment;

FIG. 5 is a flowchart showing an example of PostCode writing processing according to the present embodiment;

FIG. 6 is a flowchart showing an example of preparation processing for use of PostCode according to the present embodiment; and

FIG. 7 is a flowchart showing an example of the PostCode use processing according to the present embodiment.

Claims

1. A control apparatus that uses a correction value for head position written in a recording medium to control head position, comprising: an allowable range acquisition section that acquires a correction value allowable range which is a previously set allowable range of a correction value; anda head position control section that controls head position using a read out correction value in the case where the correction value that has been read out from the recording medium falls within the correction value allowable range acquired by the allowable range acquisition section.

2. The control apparatus according to claim 1, wherein in the case where a correction value that has been read out from the storage medium falls outside the correction value allowable range acquired by the allowable range acquisition section, the head position control section controls head position without using the read out correction value.

3. The control apparatus according to claim 1, wherein in the case where a correction value that has been read out from the storage medium falls outside the correction value allowable range acquired by the allowable range acquisition section, the head position control section controls head position without using the read out correction value and inhibits data writing operation at the set head position.

4. The control apparatus according to claim 1, wherein the head position is a position in the radial direction of the storage medium, andthe correction value is a correction value in the radial direction which is included in a servo frame.

5. The control apparatus according to claim 1, wherein the correction value allowable range is previously set as the maximum and minimum values of a correction value which is measured for each predetermined area on the storage medium, andthe allowable range acquisition section acquires the maximum and minimum values of a correction value in a predetermined area including head position as a control target.

6. The control apparatus according to claim 1, wherein the allowable range acquisition section acquires a sync signal timing allowable range which is a previously set allowable range of the timing of a sync signal, andin the case where a correction value that has been read out from the storage medium falls inside the correction value allowable range acquired by the allowable range acquisition section and where the timing of a sync signal that has been read out from the recording medium falls within the sync signal timing allowable range acquired by the allowable range acquisition section, the head position control section controls head position using the read out correction value.

7. The control apparatus according to claim 6, wherein in the case where a correction value that has been read out from the storage medium falls outside the correction value allowable range acquired by the allowable range acquisition section or where the timing of a sync signal that has been read out from the recording medium falls outside the sync signal timing allowable range acquired by the allowable range acquisition section, the head position control section controls head position without using the read out correction value and inhibits data writing operation at the set head position.

8. The control apparatus according to claim 6, wherein the sync signal timing allowable range is previously set as the maximum and minimum values of a time difference between timing of two sync signals in a servo frame, the time difference being measured for each predetermined area on the storage medium, andthe allowable range acquisition section acquires the maximum and minimum values of a time difference in a predetermined area including head position as a control target.

9. The control apparatus according to claim 1, wherein the read out correction value is a correction value that the head position control section has read out one round before head position set as a control target.

10. A storage apparatus that uses a correction value for head position written in a recording medium to control head position, comprising: an allowable range acquisition section that acquires a correction value allowable range which is a previously set allowable range of a correction value; anda head position control section that controls head position using a read out correction value in the case where the correction value that has been read out from the recording medium falls within the correction value allowable range acquired by the allowable range acquisition section.

11. The storage apparatus according to claim 10, wherein in the case where a correction value that has been read out from the storage medium falls outside the correction value allowable range acquired by the allowable range acquisition section, the head position control section controls head position without using the read out correction value.

12. The storage apparatus according to claim 10, wherein in the case where a correction value that has been read out from the storage medium falls outside the correction value allowable range acquired by the allowable range acquisition section, the head position control section controls head position without using the read out correction value and inhibits data writing operation at the set head position.

13. The storage apparatus according to claim 10, wherein the head position is a position in the radial direction of the storage medium, andthe correction value is a correction value in the radial direction which is included in a servo frame.

14. The storage apparatus according to claim 10, wherein the correction value allowable range is previously set as the maximum and minimum values of a correction value which is measured for each predetermined area on the storage medium, andthe allowable range acquisition section acquires the maximum and minimum values of a correction value in a predetermined area including head position set as a control target.

15. The storage apparatus according to claim 10, wherein the allowable range acquisition section acquires a sync signal timing allowable range which is a previously set allowable range of the timing of a sync signal, andin the case where a correction value that has been read out from the storage medium falls inside the correction value allowable range acquired by the allowable range acquisition section and where the timing of a sync signal that has been read out from the recording medium falls within the sync signal timing allowable range acquired by the allowable range acquisition section, the head position control section controls head position using the read out correction value.

16. The storage apparatus according to claim 15, wherein in the case where a correction value that has been read out from the storage medium falls outside the correction value allowable range acquired by the allowable range acquisition section or where the timing of a sync signal that has been read out from the recording medium falls outside the sync signal timing allowable range acquired by the allowable range acquisition section, the head position control section controls head position without using the read out correction value and inhibits data writing operation at the set head position.

17. The storage apparatus according to claim 15, wherein the sync signal timing allowable range is previously set as the maximum and minimum values of a time difference between timing of two sync signals in a servo frame, the time difference being measured for each predetermined area on the storage medium, andthe allowable range acquisition section acquires the maximum and minimum values of a time difference in a predetermined area including head position set as a control target.

18. The storage apparatus according to claim 10, wherein the read out correction value is a correction value that the head position control section has read out one round before head position set as a control target.

19. A head control method that uses a correction value for head position written in a recording medium to control head position, comprising: an allowable range acquisition step that acquires a correction value allowable range which is a previously set allowable range of a correction value; anda head position control step that controls head position using a read out correction value in the case where the correction value that has been read out from the recording medium falls within the correction value allowable range acquired by the allowable range acquisition step.

20. The head control method according to claim 19, wherein in the case where a correction value that has been read out from the storage medium falls outside the correction value allowable range acquired by the allowable range acquisition step, the head position control step controls head position without using the read out correction value.