Granted Patent B2

US 8,107,180 · App. 12/505,085 · Granted Jan 31, 2012

Abstract

Claims (26)

1. A hard-disk drive comprising:

a magnetic-recording disk including tracks on which a plurality of patterned bit-cells that are isolated magnetically from each other are aligned at predetermined alignment pitches;

a magnetic-recording head which is configured to follow tracks and to write and to read data;

a signal-processing unit which is configured to generate a recording signal based on a write-clock signal with cycles corresponding to said alignment pitches of said patterned bit-cells, and to output said recording signal to said magnetic-recording head;

a phase-detecting unit which is configured to detect a phase of said write-clock signal when said magnetic-recording head reaches an end point of a predetermined range including a range into which data are written by said magnetic-recording head in said tracks, wherein the predetermined range is approximately half the alignment pitches of said patterned bit-cells; and

a determination-processing unit which is configured to determine success of data writing based on a difference between an expected value and a detected value of said phase of said write-clock signal when said magnetic-recording head reaches said end point of said predetermined range, without requiring the performance of a verification process.

2. The hard-disk drive of claim 1 , wherein said phase-detecting unit is configured to detect said phase of said write-clock signal when said magnetic-recording head reaches each of a start point and said end point of said predetermined range; and

said determination-processing unit is configured to obtain said expected value based on said detected value of said phase of said write-clock signal when said magnetic-recording head reaches said start point of said predetermined range.

3. The hard-disk drive of claim 2 , wherein said determination-processing unit is configured to obtain said expected value based on said a length of said predetermined range and said alignment pitches of said patterned bit-cells.

4. The hard-disk drive of claim 1 , further comprising:

a counter, wherein said counter is configured to count said value of said write-clock signal during a period when said magnetic-recording head passes through said predetermined range; and

wherein said determination-processing unit is configured to determine success of data writing based on said value of said counted write-clock signal.

5. The hard-disk drive of claim 1 , further comprising: a time-detecting unit, wherein said time-detecting unit is configured to detect a time interval during which said magnetic-recording head passes through said predetermined range; and

wherein said determination-processing unit is configured to determine success of data writing based on said detected time interval.

6. The hard-disk drive of claim 1 , wherein said determination-processing unit is configured to send an instruction to write said data again upon determining that said data writing has failed.

7. A hard-disk drive comprising:

a magnetic-recording disk including tracks on which a plurality of patterned bit-cells that are isolated magnetically from each other are aligned at predetermined alignment pitches;

a magnetic-recording head which is configured to follow said tracks and to write and to read data;

a signal-processing unit which is configured to generate a recording signal based on a write-clock signal with cycles corresponding to said alignment pitches of said patterned bit-cells, and to output said recording signal to said magnetic-recording head;

a time-detecting unit which is configured to detect a time interval during which said magnetic-recording head passes through a predetermined range including a range into which data are written by said magnetic-recording head in said tracks, wherein the predetermined range is approximately half the alignment pitches of said patterned bit-cells; and

a determination-processing unit which is configured to determine success of data writing by said magnetic-recording head based on a difference between an expected value and a detected value of said time interval during which said magnetic-recording head passes through said predetermined range, without requiring the performance of a verification process.

8. The hard-disk drive of claim 7 , wherein said determination-processing unit is configured to obtain said expected value based on a length of said predetermined range and a tracking speed of said magnetic-recording head with respect to said tracks.

9. A control method for magnetic recording on patterned media of a hard-disk drive, said method comprising:

accessing a plurality of patterned bit-cells that are isolated magnetically from each other are aligned at predetermined alignment pitches;

detecting a phase of a write-clock signal when a magnetic-recording head reaches an end point of a predetermined range including a range into which data is written by said magnetic-recording head in said tracks, wherein the predetermined range is approximately half the alignment pitches of the patterned bit-cells; and

determining success of data writing by said magnetic-recording head based on a difference between an expected value and a detected value of said phase of said write-clock signal when said magnetic-recording head reaches said end point of said predetermined range without requiring the performing a verification process.

Assignments (7)