WO1996021927B1 - Disk drive stiction release system - Google Patents
Disk drive stiction release systemInfo
- Publication number
- WO1996021927B1 WO1996021927B1 PCT/US1996/000134 US9600134W WO9621927B1 WO 1996021927 B1 WO1996021927 B1 WO 1996021927B1 US 9600134 W US9600134 W US 9600134W WO 9621927 B1 WO9621927 B1 WO 9621927B1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- frequency
- heads
- spindle motor
- disk drive
- actuator
- Prior art date
Links
- 230000000875 corresponding Effects 0.000 claims abstract 7
- 230000001276 controlling effect Effects 0.000 claims 2
- 230000000284 resting Effects 0.000 claims 1
Abstract
A disk drive including firmware for overcoming stiction and breaking free the heads of a disk drive which may adhere to the disk surface when the disk is at rest. Upon start-up of the disk drive, if stiction at the head/disk interface occurs, the voltage to the spindle motor and/or actuator motor may be rapidly fluctuated so as to cause a pulsing of the spindle motor and/or actuator motor. Pulsing both the spindle motor and actuator motor creates forces in a plurality of radial directions to allow the head(s) to break free from the disk(s) in the direction of least resistance. Moreover, as the resonant frequency of the spindle motor varies depending on the number of heads that are stuck, the firmware pulses over a range of frequencies including the various resonant frequencies of the spindle motor corresponding to various numbers of heads stuck.
Claims
1. For use in a disk drive comprising a storage disk having data tracks and a landing zone, a spindle motor for rotating storage disk, a head for transferring data to and from the data tracks and arranged to fly above the data tracks during a period of operation of the disk drive and to contact the landing zone during a period of non-operation of the disk drive, an actuator for controllably positioning the head at preselected radial positions of the disk including the data tracks and the landing rone, and control electronics to control operation of the spindle motor and the actuator by transmitting control signals, a method for overcoming stiction between the head and the landing zone upon transition from non-operation to operation of the disk drive by operating the control electronics, during transition from non-operation to operation of the disk drive, to generate control signals, comprising the steps of: i) pulsing the spindle motor at a first preselected frequency to apply a force that frets the motion of the storage disk in the circumferential direction, ii) pulsing the actuator at a second preselected frequency to apply a force that frets the motion of the actuator in the radial direction, and iii) coordinating the pulsing of the spindle motor and the actuator to cause a resulting force acting upon the head at the contact between the head and the landing zone that changes angular direction and includes a direction of least stiction between the head and the landing zone.
2. The method of claim 1, wherein the first frequency equals the second frequency and the second frequency is out of phase relative to the first frequency.
3. The method of claim 2, wherein the second frequency is out of phase relative to the first frequency by a period equal to τ/2.
4. The method of cl-aim 1, wherein the first frequency equals the second frequency, which frequency has a value substantially unequal to a resonant frequency of the spindle motor or actuator.
-20-
5. The method of claim 1, wherein the first frequency equals the second frequency, which frequency has a value approximately equal to a resonant frequency of the spindle motor or actuator.
6. The method of either one of claims 4 and 5, wherein the second frequency is out of phase relative to the first frequency.
7. The method of claim 6, wherein the second frequency is out of phase relative to the first frequency by a period equal to x/2.
8. For use in a disk drive comprising a stack of storage disks, each having data tracks and a landing zone, a spindle motor for rotating the stack of storage disks, a plurality of heads n, each one of the heads for transferring data to and from the data tracks of a respective one of the stack of storage disks and arranged to fly above the respective data tracks during a period of operation of the disk drive and to contact the respective landing zone during a period of non- operation of the disk drive, a plurality of actuators, each one of the actuators for controllably positioning a respective one of the plurality of heads at preselected radial positions of the disk corresponding to the respective one of the heads including the data tracks and the landing zone, and control electronics to control operation of the spindle motor and the actuators by transmitting control signals, a method for overcoming stiction between the heads and the landing zones upon transition from non-operation to operation of the disk drive by operating the control electronics, during transition from non-operation to operation of the disk drive, to generate control signals, comprising the steps of: i) pulsing the spindle motor at each of a first preselected set of frequencies to apply a force that frets the motion of the storage disk in the circumferential direction, ii) pulsing the actuators at each of a second preselected set of frequencies to apply a force that frets the motion of the actuator in the radial direction, and iii) coordinating the pulsing of the spindle motor and the actuators to cause a resulting force acting upon the head at the contact between the head and the landing zone that changes angular direction and includes a direction of least stiction between the he-ad and the landing zone.
9. The method of claim 8, wherein the first pr&selected set of frequencies includes a plurality of frequencies corresponding to the resonant frequencies of the spindle motor when one or two or. . . n of the heads is held by stiction to its respective landing zone.
10. A disk drive comprising: a storage disk having data tracks and a landing zone; a spindle motor, responsive to control signals, for rotating storage disk; a head for transferring data to and from the data tracks and arranged to fly above the data tracks during a period of operation of the disk drive and to contact the landing zone during a period of non-operation of the disk drive; an actuator responsive to control signals to controllably position the head at preselected radial positions of the disk including the data tracks and the landing zone; and control electronics operating during a transition from non-operation to operation of the disk drive, to generate the control signals to: i) pulse the spindle motor at a first preselected frequency to apply a force that frets the motion of the storage disk in the circumferential direction, ϋ) pulse the actuator at a second preselected frequency to apply a force that frets the motion of the actuator in the radial direction, and iii) coordinate the pulsing of the spindle motor and the actuator to cause a resulting force acting upon the head at the contact between the head and the landing zone that changes angular direction and includes a direction of least stiction between the head and the landing zone.
-22-
11. The disc drive of claim 10, wherein the first frequency equals the second frequency and the second frequency is out of phase relative to the first frequency.
12. The disc drive of claim 11, wherein the second frequency is out of phase relative to the first frequency by a period equal to τ/2.
13. The disc drive of claim 10, wherein the first frequency equals the second frequency, which frequency has a value substantially unequal to a resonant frequency of the spindle motor or actuator.
14. The disc drive of claim 10, wherein the first frequency equals the second frequency, which frequency has a value approximately equal to a resonant frequency of the spindle motor or actuator.
15. The disc drive of either one of claims 13 and 14, wherein the second frequency is out of phase relative to the first frequency.
16. The disc drive of claim 15, wherein the second frequency is out of phase relative to the first frequency by a period equal to τ/2.
17. A disk drive comprising: a stack of storage disks, each having data tracks and a landing zone; a spindle motor, responsive to control signals, for rotating stack of storage disks; a plurality of heads, each one of the heads for transferring data to and from the data tracks of a respective one of the stack of storage disks and arranged to fly above the respective data tracks during a period of operation of the disk drive and to contact the respective landing zone during a period of non-operation of the disk drive; a plurality of actuators, each one of the actuators responsive to control signals for controllably positioning a respective one of the plurality of heads at
-23- preselected radial positions of the disk corresponding to the respective one of the heads including the data tracks and the landing zone; and control electronics operating during a transition from non-operation to operation of the disk drive, to generate the control signals to: i) pulse the spindle motor at each of a first preselected set of frequencies to apply a force that frets the motion of the storage disk in the circumferential direction, ii) pulse the actuators at each of a second preselected set of frequencies to apply a force that frets the motion of the actuator in the radial direction, and iii) coordinate the pulsing of the spindle motor and the actuators to cause a resulting force acting upon the head at the contact between the head and the landing zone that continuously changes angular direction and includes a direction of least stiction between the head and the landing zone.
18. The disk drive of claim 17, wherein the first preselected set of frequencies includes at least a frequency corresponding to the resonant frequency of the spindle motor when one of the heads is held by stiction to its respective landing zone, a frequency corresponding to the resonant frequency of the spindle motor when two of the heads are held by stiction to their respective landing zones, and a frequency equal to the number of heads in the plurality of heads.
19. In a disk drive including one or more heads supported on a movable actuator for transferring data to and from a plurality of disks, and a motor means for creating relative motion between the one or more heads and the plurality of disks, a method for overcoming stiction between the one or more heads and the plurality of disks, comprising the step of pulsing the motor means and pulsing the actuator at one or more different frequencies W2 to amplify a force exerted at stiction interfaces between the one or more heads and the respective surfaces of the plurality of storage disks.
-24-
20. The method for overcoming stiction as recited in claim 19, wherein the frequencies Wj and W2 includes at least approximate resonant frequencies of the motor means with 1 head stuck, 2 heads stuck, etc., up to N heads stuck, where N equals the total number of heads in the one or more heads.
21. In a disk drive including one or more heads supported on a movable actuator for transferring data to and from a plurality of disks, and a spindle motor for rotating the plurality of disks, a method for overcoming stiction between the one or more heads and the plurality of disks, comprising the steps of pulsing the spindle motor over a range of predetermined frequencies, said predetermined frequencies including at least approximate resonant frequencies of the spindle motor with various numbers of heads stuck to the plurality of disks and simultaneously pulsing said actuator over said range of frequencies.
22. The method of claim 21, wherein the various number of heads stuck varies from 1 to N, where N equals the total number of heads in the one or more heads.
23. The method of claim 21, wherein pulsing of said spindle motor occurs at no greater than four-hundred hertz (400Hz) and no less than fifty hertz (50Hz).
24. In a disk drive including a head and disk assembly having one or more heads for transferring data to and from a plurality of disks, a spindle motor for rotating the plurality of disks, and an actuator assembly for positioning the one or more heads with respect to the plurality of disks, a method for overcoming stiction between the one or more heads and the plurality of disks, comprising the steps of:
-25- pulsing the spindle motor over a range of discrete frequencies, said discrete frequencies including at least approximate resonant frequencies of the head and disk assembly for 1 to N heads stuck, where N equals the total number of heads in the one or more heads; and pulsing the actuator assembly.
25. The method of claim 24, wherein the spindle motor is pulsed in a direction substantially orthogonal to a direction in which the actuator assembly is pulsed.
26. A disk drive including means for overcoming stiction of a plurality of heads on respective surfaces of at least one storage disk upon start-up of the disk drive, comprising: a housing; a head and disk assembly, including: the at least one storage disk within said housing for storing data, the at least one storage disk including a landing zone; rotating means for rotating the at least one storage disk, the plurality of heads for transferring said data to and from the at least one storage disk, and a plurality of bearing means on which the plurality of heads are mounted, said plurality of bearing means resting on a section of said landing zone on each of the at least one storage disks during nonoperational periods of the disk drive; and control means for controlling said transfer of data and for controlling the rotation of said rotating means, said control means further including means for pulsing said rotating means over a range of frequencies, said range of frequencies including at least approximate resonant frequencies of said head and disk assembly corresponding to 1 head stuck, 2 heads stuck, etc. , up to N heads stuck, where N equals the total number of heads in the plurality of heads, said pulsing means provided to free said bearing means from said landing zone on each of the at least one storage disks upon start-up of the disk drive.
-26-
27. The disk drive of claim 26, wherein said rotating means pulses at no greater than four-hundred hertz (400Hz) and no less than fifty hertz (50Hz).
28. A disk drive as recited in claim 26, further comprising: actuator means within said housing for positioning the plurality of heads with respect to the at least one storage disk; and wherein said control means further includes second pulsing means for pulsing said actuator means, said second pulsing means provided to free said bearing means from said landing zone on each of the at least one storage disks upon start-up of the disk drive.
29. A method as claimed in claim 9 including the step of pulsing the spindle motor and the actuator at the same frequency.
30. A method as claimed in claim 29 wherein the motor and the actuator are pulsed at said set of frequencies sequentially in a reverse order from said resonant frequency when said n heads are stuck to said resonant frequency when said one head is stuck.
31. A method as claimed in claim 29 wherein said second frequency is out of phase with said first frequency.
32. A method as claimed in claim 31 wherein said second frequency is out of phase with said first frequency by a period equal to x/2.
-27m
Priority Applications (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR1019970704658A KR100276754B1 (en) | 1995-01-09 | 1996-01-04 | How to overcome stictions on disk drives and disk drives |
| DE69600790T DE69600790T2 (en) | 1995-01-09 | 1996-01-04 | ADHESIVE RELEASE DEVICE FOR DISK DRIVE |
| JP8521745A JPH10506217A (en) | 1995-01-09 | 1996-01-04 | Disk drive stick release system |
| EP96905113A EP0803119B1 (en) | 1995-01-09 | 1996-01-04 | Disk drive stiction release system |
| HK98102783A HK1003675A1 (en) | 1995-01-09 | 1998-04-02 | Disk drive stiction release system |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US37044595A | 1995-01-09 | 1995-01-09 | |
| US08/370,445 | 1995-01-09 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| WO1996021927A1 WO1996021927A1 (en) | 1996-07-18 |
| WO1996021927B1 true WO1996021927B1 (en) | 1996-09-26 |
Family
ID=23459696
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| PCT/US1996/000134 WO1996021927A1 (en) | 1995-01-09 | 1996-01-04 | Disk drive stiction release system |
Country Status (8)
| Country | Link |
|---|---|
| US (1) | US5801505A (en) |
| EP (1) | EP0803119B1 (en) |
| JP (1) | JPH10506217A (en) |
| KR (1) | KR100276754B1 (en) |
| CN (1) | CN1086043C (en) |
| DE (1) | DE69600790T2 (en) |
| HK (1) | HK1003675A1 (en) |
| WO (1) | WO1996021927A1 (en) |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100194029B1 (en) * | 1996-12-20 | 1999-06-15 | 윤종용 | Stiction Error Detection Circuit and Method of Hard Disk Drive |
| US5982571A (en) * | 1997-06-30 | 1999-11-09 | Quantum Corporation | Disk drive with closed loop commutator and actuator oscillator |
| US6587299B1 (en) | 1999-01-29 | 2003-07-01 | Maxtor Corporation | Method for overcoming a stiction condition in disk drive |
| US6501625B1 (en) * | 1999-06-29 | 2002-12-31 | Hutchinson Technology Incorporated | Disk drive suspension with multi-layered piezoelectric actuator controlled gram load |
| US6882495B2 (en) | 2001-12-10 | 2005-04-19 | Seagate Technology Llc | Wear reduction of a disc surface using an adaptive dither process |
| US20030184907A1 (en) * | 2002-03-29 | 2003-10-02 | Seagate Technology Llc | Method for boosting a disc drive motor stiction breakaway performance |
| US20070268629A1 (en) * | 2006-05-18 | 2007-11-22 | Seagate Technology Llc | Suspension Buckling Limiter |
| US8908317B1 (en) * | 2014-01-27 | 2014-12-09 | Kabushiki Kaisha Toshiba | Method for detecting touchdown of head and disk storage apparatus |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4530021A (en) * | 1982-11-26 | 1985-07-16 | International Business Machines Corporation | Micromotion release of heads from lubricated magnetic disks |
| US4532802A (en) * | 1984-05-31 | 1985-08-06 | International Business Machines Corporation | Apparatus for analyzing the interface between a recording disk and a read-write head |
| US4970610A (en) * | 1988-10-04 | 1990-11-13 | International Business Machines Corporation | Magnetic disk drive start procedure for starting reaction torque amplification |
| EP0573964B1 (en) * | 1992-06-08 | 1998-11-25 | Hewlett-Packard Company | Bi-polar disk torquing system for a disk drive to free stuck transducers |
| US5384675A (en) * | 1993-09-08 | 1995-01-24 | International Business Machines Corporation | Disk drive with controlled actuator oscillation for release of head carriers |
-
1996
- 1996-01-04 JP JP8521745A patent/JPH10506217A/en active Pending
- 1996-01-04 KR KR1019970704658A patent/KR100276754B1/en not_active IP Right Cessation
- 1996-01-04 DE DE69600790T patent/DE69600790T2/en not_active Expired - Fee Related
- 1996-01-04 WO PCT/US1996/000134 patent/WO1996021927A1/en active IP Right Grant
- 1996-01-04 CN CN96191939A patent/CN1086043C/en not_active Expired - Fee Related
- 1996-01-04 EP EP96905113A patent/EP0803119B1/en not_active Expired - Lifetime
-
1997
- 1997-04-23 US US08/835,837 patent/US5801505A/en not_active Expired - Lifetime
-
1998
- 1998-04-02 HK HK98102783A patent/HK1003675A1/en not_active IP Right Cessation
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