Preformat method for magnetic recording medium, magnetic recording medium, and magnetic recording and reproducing apparatus

• US 20040042107A1
• Filed: 08/01/2003
• Published: 03/04/2004
• Est. Priority Date: 08/30/2002
• Status: Active Grant

• Current Assignee: Toshiba Storage Device Incorporated (Toshiba Corporation)
• Original Assignee: Fujitsu Limited
• Inventors: Ozaki, Kazuyuki, Kuroda, Sumio
• Granted Patent: US 7,203,014 B2
• Time in Patent Office: Days
• US Class Current: 360/51
• CPC Class Codes: G11B 20/1403 characterised by the use of two levels
• CPC Class Codes: G11B 2220/20 Disc-shaped record carriers
• CPC Class Codes: G11B 27/32 on separate auxiliary tracks of the same or an auxiliary record carrier
• CPC Class Codes: G11B 5/012 Recording on, or reproducing or erasing from, magnetic disks G11B17/00, G11B19/00 take precedence
• CPC Class Codes: G11B 5/59616 Synchronisation; Clocking G11B5/59622 takes precedence
• CPC Class Codes: G11B 5/59633 Servo formatting G11B5/59627, G11B5/59677, G11B5/59683, G11B5/59688 take precedence
• CPC Class Codes: G11B 5/82 Disk carriers
• CPC Class Codes: H03L 7/093 using special filtering or amplification characteristics in the loop H03L7/087 - H03L7/091 take precedence
• CPC Class Codes: H03L 7/18 using a frequency divider or counter in the loop H03L7/20, H03L7/22 take precedence

Abstract

The magnetic recording and reproducing apparatus reads a transfer clock synchronized with servo information and records a write-once clock pattern in a state where 0 is set as a delay time of the delay device 13 and 1 is set as the dividing ratio of the frequency divider 17. The apparatus corrects the delay time according to the output of the phase comparator 14 which changes on the basis of the phase difference and rewrites a write-once clock pattern. Rotation of the magnetic disk, detection of the phase difference and correction of the delay time are repeatedly preformed until no change occurs in the output of the phase comparator 14. After the output stops changing, preformat information patterns excluding the servo information pattern are recorded as fine patterns by changing the dividing ratio of the frequency divider 17 to multiply the frequency.

Claims

1. A preformat method for a magnetic recording medium, for recording preformat information including servo information on a magnetic recording medium by a magnetic recording apparatus including a recording head, comprising steps of:

recording at least the servo information of the preformat information on the magnetic recording medium by magnetic transfer; and

recording preformat information excluding the servo information on the magnetic recording medium by the recording head.

2. A preformat method for a magnetic recording medium, for recording preformat information including servo information on a magnetic recording medium by a magnetic recording and reproducing apparatus including a recording head and a reproducing head, comprising steps of:

recording at least the servo information of the preformat information on the magnetic recording medium by magnetic transfer;

reproducing preformat information recorded by magnetic transfer;

fining a pattern of the reproduced preformat information; and

recording the fined preformat information on the magnetic recording medium by the recording head.

3. A preformat method for a magnetic recording medium, for recording preformat information including servo information on a magnetic recording medium by a magnetic recording and reproducing apparatus including a recording head and a reproducing head, comprising steps of:

recording at least the servo information of the preformat information on the magnetic recording medium by magnetic transfer;

recording a transfer clock pattern, which is synchronized with a pattern of the servo information, on the magnetic recording medium; and

recording preformat information excluding the servo information on the magnetic recording medium by the recording head, as patterns synchronized with the transfer clock pattern.

4. The preformat method for a magnetic recording medium according to claim 3, further comprising steps of:

reproducing preformat information recorded by magnetic transfer;

fining a pattern of the reproduced preformat information; and

recording the fined preformat information on the magnetic recording medium by the recording head.

5. A magnetic recording medium comprising:

a servo information pattern of preformat information patterns, which is recorded by magnetic transfer; and

a transfer clock pattern synchronized with the servo information pattern.

6. The magnetic recording medium according to claim 5, which has a circular form in a plan view, wherein the transfer clock pattern is recorded on an inner or outer periphery portion of the magnetic recording medium.

7. The magnetic recording medium according to claim 6, wherein information is recorded by a perpendicular magnetic recording method.

8. The magnetic recording medium according to claim 5, wherein information is recorded by a perpendicular magnetic recording method.

9. A magnetic recording and reproducing apparatus comprising:

a reproducing head for reproducing information recorded on a magnetic recording medium having at least a servo information pattern of preformat information patterns which is recorded thereon in advance by magnetic transfer; and

a recording head for recording preformat information patterns excluding the servo information pattern on the magnetic recording medium.

10. The magnetic recording and reproducing apparatus according to claim 9, wherein the magnetic recording medium has a transfer clock pattern, which is synchronized with the servo information pattern, recorded thereon in advance by magnetic transfer, further comprising a phase synchronizing unit for synchronizing a phase of a clock of the recording head for recording information with a phase of a transfer clock obtained by reproducing the transfer clock pattern by the reproducing head.

11. The magnetic recording and reproducing apparatus according to claim 10, further comprising a frequency multiplying unit for multiplying a frequency for recording information in a clock finer than the transfer clock.

12. The magnetic recording and reproducing apparatus according to claim 9, wherein the magnetic recording medium has a transfer clock pattern, which is synchronized with the servo information pattern, recorded thereon in advance by magnetic transfer, further comprising a phase difference detecting unit for detecting a phase difference between a transfer clock which is obtained by reproducing the transfer clock pattern by the reproducing head and a write-once clock which is recorded by the recording head.

13. The magnetic recording and reproducing apparatus according to claim 12, further comprising a frequency multiplying unit for multiplying a frequency for recording information in a clock finer than the transfer clock.

14. The magnetic recording and reproducing apparatus according to claim 9, further comprising a frequency multiplying unit for multiplying a frequency for recording information in a clock finer than the transfer clock.

15. The magnetic recording and reproducing apparatus according to claim 9, wherein the magnetic recording medium has a transfer clock pattern, which is synchronized with the servo information pattern, recorded thereon in advance by magnetic transfer, further comprising phase synchronizing means for synchronizing a phase of a clock of the recording head for recording information with a phase of a transfer clock obtained by reproducing the transfer clock pattern by the reproducing head.

16. The magnetic recording and reproducing apparatus according to claim 15, further comprising means for multiplying a frequency for recording information in a clock finer than the transfer clock.

17. The magnetic recording and reproducing apparatus according to claim 9, wherein the magnetic recording medium has a transfer clock pattern, which is synchronized with the servo information pattern, recorded thereon in advance by magnetic transfer, further comprising phase difference detecting means for detecting a phase difference between a transfer clock which is obtained by reproducing the transfer clock pattern by the reproducing head and a write-once clock which is recorded by the recording head.

18. The magnetic recording and reproducing apparatus according to claim 17, further comprising means for multiplying a frequency for recording information in a clock finer than the transfer clock.

19. The magnetic recording and reproducing apparatus according to claim 9, further comprising means for multiplying a frequency for recording information in a clock finer than the transfer clock.