Disk drive stiction release system

Claim 2

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 zone, 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.

Claim 3

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.

Claim 4

The method of claim 2, wherein the second frequency is out of phase relative to the first frequency by a period equal to π/2.

Claim 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.

Claim 6

The method of claim 4, wherein the second frequency is out of phase relative to the first frequency.

Claim 7

The method of claim 5, wherein the second frequency is out of phase relative to the first frequency by a period equal to π/2.

Claim 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 head and the landing zone.

Claim 9

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 head and the landing zone.

Claim 10

A method as claimed in claim 1 including the step of pulsing the spindle motor and the actuator at the same frequency.

Claim 11

The method of claim 8, wherein the step of pulsing the spindle motor at said first preselected set of frequencies includes a first frequency corresponding to a first resonant frequency of the spindle motor when one of the heads is held by stiction to its respective landing zone, a second frequency corresponding to a second resonant frequency of spindle motor when two of the heads are held by stiction to their respective landing zones, and continuing said pulsing step utilizing each resonant frequency of said set up to a resonant frequency of the motor corresponding to all of said n heads being stuck.

Claim 12

A method as claimed in claim 9 wherein said spindle motor and said actuator are each pulsed at different frequencies of said first and second sets of resonant frequencies of said spindle motor.

Claim 13

A method as claimed in claim 10 wherein said first and second sets of frequencies include substantially the same resonant frequencies of the motor.

Claim 14

A method as claimed in claim 11 wherein the frequency at which the actuator is pulsed is out of phase relative to the frequency at which the motor is pulsed by a period of π/ 2 .

Claim 15

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, ii) 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.

Claim 16

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, ii) 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.

Claim 17

The disk drive of claim 13, wherein the first frequency equals the second frequency and the second frequency is out of phase relative to the first frequency.

Claim 18

The disk drive of claim 14, wherein the second frequency is out of phase relative to the first frequency by a period equal to π/2.

Claim 19

The disk drive of claim 13, 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.

Claim 20

The disk drive of claim 13, 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.

Claim 21

The disk drive of either one of claims 16 and 17, wherein the second frequency is out of phase relative to the first frequency.

Claim 22

The disk drive of claim 18, wherein the second frequency is out of phase relative to the first frequency by a period equal to π/2.

Claim 23

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 nonoperation 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 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.

Claim 24

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 nonoperation 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 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.

Claim 25

The disk drive of claim 20, 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.

Claim 26

In a disk drive including one or more heads up to n heads supported on a movable actuator for radial movement across a data recording surface of a plurality of discs for transferring data to and from the data surfaces of said plurality of disks, and a motor means for causing rotation of said discs 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 at least at one frequency of a set of resonant frequencies of said motor, the set of resonant frequencies being a function of the number of said n heads stuck to an associated surface of said discs, over a range set of frequencies and substantially simultaneously pulsing the actuator at a different frequency of said set of frequencies to amplify a force exerted at stiction interfaces between the one or more heads and the respective surfaces of the plurality of storage disks.

Claim 27

In a disk drive including one or more heads up to n heads supported on a movable actuator for radial movement across a data recording surface of a plurality of discs for transferring data to and from the data surfaces of said plurality of disks, and a motor means for causing rotation of said discs 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 at least at one frequency of a set of resonant frequencies of said motor, the set of resonant frequencies being a function of the number of said n heads stuck to an associated surface of said discs, over a range set of frequencies and substantially simultaneously pulsing the actuator at a different frequency of said set of frequencies to amplify a force exerted at stiction interfaces between the one or more heads and the respective surfaces of the plurality of storage disks.

Claim 28

The method for overcoming stiction as recited in claim 22, wherein the of frequencies includes at least approximate resonant frequencies of the motor means with 1 head stuck, 2 heads stuck, . . . , up to n heads stuck, where n equals the total number of heads in the one or more heads.

Claim 29

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.

Claim 30

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.

Claim 31

The method of claim 24, wherein the various numbers of heads stuck varies from 1 to N, where N equals the total number of heads in the one or more heads.

Claim 32

The method of claim 24, wherein pulsing of said spindle motor occurs at no greater than four-hundred hertz (400 Hz) and no less than fifty hertz (50 Hz).

Claim 33

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: 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.

Claim 34

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: 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.

Claim 35

The method of claim 27, wherein the spindle motor is pulsed in a direction substantially orthogonal to a direction in which the actuator assembly is pulsed.

Claim 36

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 stuck head, 2 heads stuck, . . . , 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.

Claim 37

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 stuck head, 2 heads stuck, . . . , 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.

Claim 38

The disk drive of claim 29, wherein said rotating means pulses at no greater than four-hundred hertz (400 Hz) and no less than fifty hertz (50 Hz).

Claim 39

A disk drive as recited in claim 29, 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.

Claim 40

A method as claimed in claim 8 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.

Claim 41

A method as claimed in claim 8 wherein said second frequency is out of phase with said first frequency.

Claim 42

A method as claimed in claim 33 wherein said second frequency is out of phase with said first frequency by a period equal to π/2.