1. A track zero determination method in a disk drive, the method comprising:
(a) performing a sequential seek operation on target tracks of a disk, in units of predetermined numbers of tracks, outwardly, from a track separate from a physical track zero position obtained in a servo track write operation, by a predetermined distance toward the physical track zero position;
(b) determining whether the target tracks belong to a region where a track-following operation is normally performed, and determining whether an actuator arm connected to a transducer is in contact with a mechanical buffering unit during the sequential seek operation of operation (a); and
(c) selecting as a logical track zero, the target track belonging to the region where the track following operation is normally performed and the actuator arm is not in contact with the mechanical buffering unit.
2. The method according to claim 1, wherein the mechanical buffering unit is an outer crash stop (OCS) preventing the transducer from moving to a position where servo information is not written on the disk.
3. The method according to claim 1, wherein the determination of whether the actuator arm is in contact with the mechanical buffering unit is based on a compensated harmonic component of a disk rotational frequency obtained by a state feed back method used in a repetitive run out (RRO) compensation process.
4. The method according to claim 3, wherein the harmonic component is a second harmonic component.
5. The method according to claim 1, wherein the method further comprises:
treating the disk drive as defective if a number of times that the track-following operation is not normally performed during the sequential seek operation of operation (a) is greater than a predetermined threshold value.
6. A track zero determination method in a disk drive, the method comprising:
(a) selecting an initial logical track zero value of a disk using a logical track zero determination method;
(b) determining whether there is a defect in a track of a system region based on the logical track zero value, wherein the system region is a region where system information is written;
(c) resetting a track next to the track having the defect as a logical track zero value if there is a defect in a track of the system region, and if not, determining a current logical track zero value to be a final logical track zero value; and
(d) comparing the reset logical track zero value with a predetermined threshold value, treating the disk drive as defective if the reset logical track zero value is more than the threshold value, and if not, returning to operation (b).
7. The method according to claim 6, wherein the system information includes information on defects located in a data region, servo parameters, and channel parameters.
8. The method according to claim 6, wherein the system region begins at the logical track zero position.
9. The method according to claim 6, wherein the logical track zero determination method is a method of determining the logical track zero by performing a sequential seek operation on tracks of the disk, in units of predetermined numbers of tracks, outwardly, from a track separate from a physical track zero position obtained in a servo track write operation, by a predetermined distance toward the physical track zero position, and selecting as the logical track zero, a track belonging to a region where a track-following operation is normally performed and an actuator arm connected to a transducer is not in contact with a mechanical buffering unit during the sequential seek operation.
10. The method according to claim 9, wherein the mechanical buffering unit is an OCS preventing the transducer from moving to a position where servo information is not written on the disk.
11. The method according to claim 9, wherein the determination whether the actuator arm is in contact with the mechanical buffering means is based on a compensated harmonic component of a disk rotational frequency obtained by a state feed back method used in an RRO compensation process.
12. The method according to claim 11, wherein the harmonic component is a second harmonic component.
13. The method according to claim 9, wherein the method further comprises a step of treating the disk drive as a defective one if the number of cases where the track-following operation is not normally performed during the sequential seek operation is beyond a predetermined threshold value.
14. A disk drive comprising:
a disk where servo information is written;
a spindle motor rotating the disk;
a transducer reading andor writing information from andor to the disk;
an actuator arm connected to the transducer;
a mechanical buffering unit limiting a displacement of the actuator arm;
a voice coil motor(VCM) rotating the actuator arm to move the transducer on the disk;
a memory storing firmware used to control the disk drive and a logical track zero value; and
a controller:
controlling the VCM in accordance with a seek routine,
determining the logical track zero value in response to a logical track zero determination command by performing a sequential seek operation on target tracks, in units of predetermined numbers of tracks, outwardly, from a track separate from a physical track zero position obtained in a servo track write operation, by a predetermined distance toward the physical track zero position, and selecting as the logical track zero the target track belonging to a region where a track-following operation is normally performed and the actuator arm is not in contact with the mechanical buffering unit during the sequential seek operation, and
performing a seek control operation based on the logical track zero value.
15. The disk drive according to claim 14, wherein the memory is a flash memory device.
16. The disk drive according to claim 14, wherein the mechanical buffering unit is an outer crash stop (OCS) preventing the transducer from moving to a position where servo information is not written on the disk
17. The disk drive according to claim 14, wherein the determination whether the actuator arm is in contact with the mechanical buffering is based on a compensated harmonic component of a disk rotational frequency obtained by a state feed back method used in an RRO compensation process.
18. The disk drive according to claim 14, wherein the harmonic component is a second harmonic component.
19. The disk drive according to claim 14, wherein the controller performs a process for treating the disk drive as defective if a number of times when the track-following operation is not normally performed during the sequential seek operation of the controller is greater than a predetermined threshold value.
20. A disk drive comprising:
a disk where servo information is recorded;
a spindle motor rotating the disk;
a transducer reading andor writing information from andor to the disk;
an actuator arm connected to the transducer;
a mechanical buffering unit limiting a displacement of the actuator arm;
a Voice Coil Motor (VCM) rotating the actuator arm to move the transducer on the disk;
a memory storing firmware used to control the disk drive and a logical track zero value; and
a controller:
controlling the VCM in accordance with a seek routine;
determining the logical track zero value by using a predetermined logical track zero determination method and a method to detect a defect in a track of a system region where system information is written based on the logical track zero value, and resetting as the logical track zero value, a track next to a defective track having the defect in the system region, and
performing a seek control operation based on the logical track zero value.
21. The disk drive according to claim 20, wherein the controller treats the disk drive as defective if a final logical track zero value is greater than predetermined threshold value.
22. The disk drive according to claim 20, wherein the predetermined logical track zero determination method comprises:
performing a sequential seek operation on target tracks, in units of predetermined numbers of tracks, outwardly, from a track apart from a physical track zero position, by a predetermined distance toward the physical track zero position; and
selecting as the logical track zero, the target track belonging to a region where a track-following operation is normally performed and the actuator arm is not in contact with the mechanical buffering unit during the sequential seek operation.
23. A method to determine a logical track zero of a disk of an assembled hard disk drive, the method comprising:
initializing a seek failure counter;
determining an initial target track located a predetermined distance from a physical track zero position obtained in a servo track write operation as a current target track;
performing a sequential seek operation, seeking the current target track;
determining whether a transducer of the drive correctly follows the current target track;
if it is determined that the transducer correctly follows the current target track, determining whether an actuator arm connected to the transducer is in contact with a mechanical buffering unit;
if it is determined that the transducer does not correctly follow the current target track, modifying the seek failure counter to be one unit closer to a failure limit;
determining whether the seek failure counter has reached the failure limit;
if it is determined that the seek failure counter has reached the failure limit, determining the disk drive to be defective and ending the method;
if it is determined that one of the seek failure counter has not reached the failure limit, or the actuator is not in contact with the mechanical buffering unit, setting the current target track as a track separated from the previous target track by a predetermined number of tracks toward the physical track zero position;
determining whether a position of the current target track is farther from a spindle motor shaft of the disk drive than the physical track zero position;
if it is determined that the position of the current target track is not farther from the spindle motor shaft than the physical track zero position, performing the sequential seek operation;
if it is determined that one of the position of the current target track is farther from the spindle motor shaft than the physical track zero position, or the actuator arm is in contact with the mechanical buffering unit, selecting the current target track as the logical track zero.
24. The method according to claim 23, wherein the mechanical buffering unit is an outer crash stop preventing the transducer from moving to a position where servo information is not written on the disk.
25. The method according to claim 23, wherein the determining whether the actuator arm is in contact with the mechanical buffering unit is based on a compensated harmonic component of a disk rotational frequency obtained by a state feed back method used in a repetitive run out (RRO) compensation process.
26. The method according to claim 25, wherein the harmonic component is a second harmonic component.
27. A method to determine a logical track zero of a disk of an assembled hard disk drive, the method comprising:
determining a logical track zero in accordance with the method of claim 23;
determining whether a defect is present in a system region of the disk beginning at the logical track zero, and if not, ending the method;
if it is determined that there is a defect present in the system region, resetting the logical track zero to a track located a predetermined distance from a track with the defect;
determining whether a value of the logical track zero exceeds a predetermined threshold value;
if the value of the logical track zero exceeds the predetermined threshold value, determining the disk drive to be defective and ending the method, and if not, performing the determining whether a defect is present in a system region operation.
28. A method to determine a logical track zero of a disk of an assembled hard disk drive, the method comprising:
determining a logical track zero of the disk and setting that track as a current logical track zero;
determining whether a defect is present in a system region of the disk beginning at the current logical track zero, and if not, determining that the current logical track zero is a final logical track zero ending the method;
if it is determined that there is a defect present in the system region, resetting the logical track zero to a track located a predetermined distance from a track with the defect;
determining whether a value of the logical track zero exceeds a predetermined threshold value;
if the value of the logical track zero exceeds the predetermined threshold value, determining the disk drive to be defective and ending the method, and if not, performing the determining whether a defect is present in a system region operation.
29. The method according to claim 28, wherein the system region includes information on defects located in a data region, servo parameters, and channel parameters.
30. A method to determine a logical track zero of a disk of an assembled hard disk drive, the method comprising:
determining an initial target track as a track that is a predetermined distance from a physical track zero position obtained in a servo track write operation;
performing a sequential seek operation, seeking the target track;
determining whether the target track is located in a region of the disk where a transducer of the drive correctly follows tracks,
if so, determining whether an actuator arm connected to the transducer is in contact with a mechanical buffering unit during the sequential seek operation; and
if so, selecting the target track as the logical track zero.
31. The method according to claim 30, wherein the mechanical buffering unit is an outer crash stop preventing the transducer from moving to a position where servo information is not written on the disk.
32. The method according to claim 30, wherein the determining whether the actuator arm is in contact with the mechanical buffering unit is based on a compensated harmonic component of a disk rotational frequency obtained by a state feed back method used in a repetitive run out (RRO) compensation process.
33. The method according to claim 32, wherein the harmonic component is a second harmonic component.
34. A method to determine a logical track zero of a disk of an assembled hard disk drive, the method comprising:
determining a logical track zero of the disk and setting that track as a current logical track zero;
determining whether a defect is present in a system region of the disk beginning at the current logical track zero, and if not, determining that the current logical track zero is a final logical track zero;
if so, resetting the current logical track zero to a track located a predetermined distance from a track with the defect;
determining whether a value of the current logical track zero exceeds a predetermined threshold value;
if not, performing the operation of determining whether a defect is present in the system region.
35. A method to determine a logical track zero of a disk of a disk drive, the method comprising:
adaptively determining a logical track zero position in accordance with an assembled state of a disk drive and defects in a system region of the disk.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1-73. (canceled)
74. A composition comprising fish oil, wherein the composition comprises less than about 2 mg of sterol per gram of composition, at least about 97% triglycerides, less than about 2% diglycerides, and less than about 1% monoglycerides.
75. The composition of claim 74, wherein the fish oil comprises an Atlantic fish oil, Pacific fish oil, Mediterranean fish oil, light pressed fish oil, alkaline treated fish oil, heat treated fish oil, light and heavy brown fish oil, tuna oil, bonito oil, sea bass oil, halibut oil, spearfish oil, barracuda oil, cod oil, menhaden oil, sardine oil, pilchard oil, anchovy oil, capelin oil, Atlantic cod oil, Atlantic herring oil, Atlantic mackerel oil, Atlantic menhaden oil, salmonids oil, or combination thereof.
76. The composition of claim 74, wherein the composition comprises an EPA to DHA wt. % ratio of about 60:0.3, about 18:12, about 5:25, or about 0.8:60.
77. The composition of claim 74, wherein the composition comprises from about 1.1 to about 0.9 milligrams of sterol per gram of the composition.
78. The composition of claim 74, wherein the composition comprises about 1.0 milligram of sterol per gram of the composition.
79. The composition of claim 74, wherein the sterol is cholesterol.
80. The composition of claim 79, wherein the cholesterol is in its free form and esterified form.
81. The composition of claim 74, wherein the composition has a Gardner color of less than or equal to about 5, as determined by ASTM D 1544.
82. The composition of claim 74, wherein the composition comprises linolenic acid, octadecatetraenoic acid, eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), docosapentaenoic acid (DPA), or a residue, derivatives, or mixture thereof.
83. The composition of claim 74, wherein the composition comprises from about 10 to about 16 wt. % DHA.
84. The composition of claim 74, wherein the composition comprises from about 14 to about 20 wt. % EPA.
85. The composition of claim 74, wherein the composition has less than or equal to about 2 wt. % trans-fatty acids.
86. The composition of claim 74, wherein the composition has a p-Anisidine value of less than or equal to about 10, as determined by ISO 6885:1998.
87. The composition of claim 74, wherein the composition has a p-Anisidine value of less than or equal to about 6, as determined by ISO 6885:1998.