Magnetic disk drive and error correction method
AssigneeKabushiki Kaisha Toshiba
InventorAkifumi Okazaki
Life of this patent
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Abstract
A magnetic disk drive comprises a magnetic recording medium, a magnetic recording head for reading/writing data from/onto the magnetic recording medium, and detecting means for detecting thermal asperity by comparing the data read out from the magnetic recording medium with a predetermined value.
Claims20
A magnetic disk drive comprising:
- a magnetic recording medium;
- a magnetic head for reading/writing data from/onto the magnetic recording medium;
- detecting means for detecting thermal asperity;
- and
- rereading means for executing rereading by increasing correctable error length to longer than that of normal ON-THE-FLY correction when both reading error and thermal asperity are detected.
A magnetic disk drive comprising:
- a magnetic recording medium;
- a magnetic head for reading/writing data from/onto the magnetic recording medium;
- detecting means for detecting thermal asperity;
- and
- rereading means for executing error correction different from normal error correction when both reading error and thermal asperity are detected and an error which cannot be corrected even with a maximum error correction ability of normal ON-THE-FLY correction is detected.
A method of error correction in a magnetic disk for reading/writing data from/onto the magnetic recording medium, comprising the steps of:
- detecting a reading error,
- detecting thermal asperity, outputting a thermal asperity detection signal when thermal asperity is detected, and rereading of data is not correctly executed;
- executing rereading data different from normal error correction by setting error correction ability at a higher level which otherwise cannot be corrected with a maximum error correction ability of normal ON-THE-FLY correction.
A magnetic disk drive comprising:
- a magnetic recording medium;
- a magnetic head for reading/writing data from/onto the magnetic recording medium;
- a head amplifier for amplify the data read by said magnetic head;
- a read/write circuit for performing analog amplification of the data amplified from said head amplifier and decoding the data to a digital signal;
- a thermal asperity detection circuit for detecting an analog signal amplified by said read/write circuit and outputting a thermal asperity detection signal;
- a hard disk controller for performing a read operation of the digital signal output from said read/write circuit ;
- and
- a central processing unit for setting an error correction length to said hard disk controller on the basis of the thermal asperity detection signal from said thermal asperity detection circuit, said central processing unit resetting an error correction length to said hard disk controller, which is larger than a predetermined error correction length, to said hard disk controller and performing a reread operation when said central processing unit receives the thermal asperity detection signal output from said thermal asperity detection circuit,
- wherein said hard disk controller performs a read operation by said predetermined error length set in said central processing unit.
A method of error correction in a magnetic disk drive for reading/writing data from/onto a magnetic recording medium, comprising the steps of:
- detecting a reading error;
- detecting thermal asperity;
- performing read operation when read error can be corrected;
- outputting a thermal asperity detection signal when thermal asperity is detected;
- setting error correction ability at a higher level than that of normal ON-THE-FLY correction when a thermal asperity signal is output and rereading of data is not correctly executed;
- and
- executing rereading of data.
Dependencies are inferred from the claim text.