Method and apparatus for generating the optimum read timing for read and write offset of a magneto resistive head
First Claim
Patent Images
1. A hard disk drive, comprising:
- a disk;
a spindle motor coupled to said disk;
a head coupled to said disk, said head having a read element that is separated from a write element by an offset; and
, an electrical circuit that enables said read element as a function of the offset.
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Abstract
A method for writing and reading data in a hard disk drive and compensating for an offset between a write element and a read element of a head. The method determines an offset time by determining the difference between a desired sync byte position and an actual sync byte position located between a preamble and a data sector of the disk. The difference corresponds to the offset between the read and write elements. The offset time is subtracted from the normal time for enabling the read gate of a disk drive pre-amplifier.
72 Citations
47 Claims
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1. A hard disk drive, comprising:
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a disk;
a spindle motor coupled to said disk;
a head coupled to said disk, said head having a read element that is separated from a write element by an offset; and
,an electrical circuit that enables said read element as a function of the offset. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A hard disk drive, comprising:
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a disk that has a sync address mark, a data sector, a preamble to said data sector, and a sync byte located between said preamble and said data sector;
a spindle motor coupled to said disk;
a head coupled to said disk, said head having a read element that is separated from a write element by an offset;
a pre-amplifier circuit connected to said head, said pre-amplifier circuit having a read gate coupled to said read element;
a read/write channel circuit connected to said pre-amplifier circuit; and
,a controller connected to read/write channel circuit and said pre-amplifier circuit, said controller provides a read gate signal to said read gate to enable said read element, a timing of said read gate signal being a function of the offset. - View Dependent Claims (9, 10, 11, 12)
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13. A hard disk drive, comprising:
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a disk;
a spindle motor coupled to said disk;
a head coupled to said disk, said head having a read element that is separated from a write element by an offset; and
,circuit means for enabling said read element as a function of the offset. - View Dependent Claims (14, 15, 16, 17, 18, 19)
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20. A hard disk drive, comprising:
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a disk that has a sync address mark, a data sector, a preamble to said data sector, and a sync byte located between said preamble and said data sector;
a spindle motor coupled to said disk;
a head coupled to said disk, said head having a read element that is separated from a write element by an offset;
a pre-amplifier circuit connected to said head, said pre-amplifier circuit having a read gate coupled to said read element;
a read/write channel circuit connected to said pre-amplifier circuit; and
,controller means for providing a read gate signal to said read gate to enable said read element, a timing of said read gate signal being a function of the offset. - View Dependent Claims (21, 22, 23, 24)
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25. A method for enabling a read gate of a hard disk drive, comprising:
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reading a sync address mark of a disk with a head that has a read element offset from a write element;
generating a sector signal; and
,enabling a read gate signal at a time that is a function of the offset.
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26. A method to determine an offset between a read element and a write element of a hard disk drive, comprising:
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determining a desired sync byte location on a disk;
reading a disk with a head that has a read element;
determining an actual sync byte location of the disk; and
,generating offset information as a difference between the desired and actual sync byte locations. - View Dependent Claims (27, 28, 29, 30, 31)
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32. A circuit that controls a read/write operation of a data storage device that has a read element and a write element that are physically offset from each other, comprising:
a controller that generates a periodic timing reference signal, a read gate signal that precedes in time said periodic timing reference signal and indicates a start of a read operation, and a write gate signal that is subsequent in time to said periodic timing reference signal by an offset duration and indicates a start of a write operation. - View Dependent Claims (33, 34, 35)
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36. A data storage device, comprising:
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a storage medium;
a head coupled to said storage medium, said head having a read element that is physically offset from a write element;
a controller that generates a periodic timing reference signal, a read gate signal that precedes in time said periodic timing reference signal and indicates a start of a read operation, and a write gate signal that is subsequent in time to said periodic timing reference signal by an offset duration and indicates a start of a write operation. - View Dependent Claims (37, 38)
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39. A method for controlling the operation of a data storage device that has a read element physically offset from a write element, comprising:
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generating a write signal that is subsequent in time to a first periodic timing reference signal to initiate a write operation through the write element; and
,generating a read gate signal that precedes in time a second periodic timing reference signal to initiate a read operation through the read element. - View Dependent Claims (40)
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41. A circuit that controls a read/write operation of a data storage device that has a read element and a write element that are physically offset from each other, comprising:
a controller that generates a periodic timing reference signal, and a read gate signal that indicates a start of a read operation, said read gate signal being offset in time from the periodic timing reference signal by a duration that corresponds to the physical offset between the read element and the write element. - View Dependent Claims (42)
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43. A method for controlling the read/write operation of a data storage device that has a read element and a write element that are physically offset from each other, comprising:
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generating a write signal that is subsequent in time to a first periodic timing reference signal by an offset duration to initiate a write operation through the write element; and
,generating a read gate signal that precedes in time a second periodic timing reference signal to initiate a read operation through the read element. - View Dependent Claims (44)
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45. A method of compensating for a physical offset between a read element and a write element of a data storage device, comprising:
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writing a data pattern onto a storage medium, the data pattern including a preamble portion that has a start point;
determining a time duration between the start point of the preamble and a periodic timing reference signal; and
,offsetting at least one of a read gate signal and a write gate signal from said periodic timing reference signal by said determined time duration, said read gate signal indicating a start of a read operation, said write gate signal indicating a start of a write operation. - View Dependent Claims (46, 47)
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Specification