Recording equalizer and magnetic recording/reproducing apparatus performing write timing compensation
AssigneeHitachi, Ltd.
InventorsMasukazu Igarashi, Yohji Maruyama, Kazuetsu Yoshida, Ikuo Saitoh
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Abstract
A recording equalizer for precompensating of a write timing of magnetic information when the magnetic information is recorded by a magnetic recording head on a magnetic recording medium, includes a buffer for storing a recording object bit and bits before and after said recording object bit, and a calculator for calculating and outputting a precompensation parameter using the bits stored in the buffer by adding an offset C, having a value such as to always delay the write timing of the magnetic information, to an amount of shift determined using the bits stored in the buffer and the head velocity relative to the medium.
Claims9
A recording equalizer for precompensating of a write timing of magnetic information when the magnetic information is recorded by a magnetic recording head on a magnetic recording medium, comprising:
- a buffer for storing a recording object bit and bits before and after said recording object bit;
- and
- a calculator for calculating and outputting a precompensation parameter using the bits stored in said buffer by adding an offset C, having a value such as to always delay the write timing of the magnetic information, to an amount of shift determined using the bits stored in the buffer and the head velocity relative to the medium.
A recording equalizer for precompensating of a write timing of magnetic information when the magnetic information is recorded by a magnetic recording head on a magnetic recording medium, comprising:
- a buffer for storing a recording object bit and bits before and after said recording object bit;
- and
- a calculator for calculating and outputting a precompensation parameter using the bits stored in said buffer by adding an offset C, having a value such as to always delay the write timing of the magnetic information, to an amount of shift determined using the bits stored in the buffer and the head velocity relative to the medium, wherein, when a precompensation parameter is assumed to be d when a first bit of a dibit spaced apart by at least a three-bit length from a previous transition and by at least two-bit length from a following transition is recorded, said offset C is determined to have a value such that said precompensation parameter D is positive and is smaller than a write basic clock cycle.
A recording equalizer for precompensating of a write timing of magnetic information when the magnetic information is recorded by a magnetic recording head on a magnetic recording medium, comprising:
- a buffer for storing a recording object bit and bits before and after said recording object bit;
- and
- a calculator for calculating and outputting a precompensation parameter using the bits stored in said buffer by adding an offset C, having a value such as to always delay the write timing of the magnetic information, to an amount of shift determined using the bits stored in the buffer and the head velocity relative to the medium, wherein:
- when a precompensation parameter is assumed to be d when a first bit of a dibit spaced apart by at least a three-bit length from a previous transition and by at least two-bit length from a following transition is recorded, said offset C is determined to have a value such that said precompensation parameter d is positive and is smaller than a write basic clock cycle:
- said calculator further uses the length of one-bit length on said magnetic recording medium when said precompensation parameter d is calculated;
- and
- when recording A(n) of a bit sequence A(n−2), A(n−1), A(n), A(n+1), said precompensation parameter d is calculated in accordance with the following expression:
- d=(−f(2L)·A(n−2)·(−1)A(n−2)+A(n−1)−f(L)·A(n−1)·(−1)A(n−1)−R·f(L)·A(n+1))/v+C(S)
- where
- f( ):
- function for obtaining shift from bit length L
- v:
- head-medium relative velocity (m/s)
- L:
- one-bit length (m)
- R:
- constant.
Dependencies are inferred from the claim text.