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US 7,199,960 B1Granted
Disk drive with AC exciter for head/disk interface
AssigneeMaxtor Corporation
InventorsErhard T. Schreck, Robert E. Eaton
Life of this patent
Estimating the term…
Abstract
A disk drive includes a disk for storing information, a head with a transducer that writes data to and reads data from the disk, and an AC power source. The head is suspended adjacent to the disk and a flying height gap exists at the head/disk interface. The AC power source generates an AC exciter signal across the flying height gap that discharges electrostatic charge at the head/disk interface. The head/disk capacitance can be measured based on the AC exciter signal to sense the flying height. The AC exciter signal can also alter an attraction force between the head and the disk and thus control flying height. The AC exciter signal can also be based on a flying height signal representative of the head/disk capacitance and thus the flying height.
Claims131
A disk drive, comprising:
- a disk for storing information;
- a head suspended adjacent to the disk such that a flying height gap exists at a head/disk interface between the head and the disk, wherein the head comprises a transducer for writing data to and reading data from the disk;
- an AC power source for generating an AC exciter signal, wherein the AC power source is coupled to the head and the disk such that the AC exciter signal is present across the flying height gap;
- a capacitance sense circuit for generating a flying height signal indicative of an effective capacitance between the head and the disk at the head/disk interface in response to the AC exciter signal;
- and
- a flying height control circuit for controlling the AC power source to generate the AC exciter signal to maintain a flying height of the head with respect to the disk within a range of acceptable flying heights.
3 more elements
A disk drive, comprising:
- a disk for storing information;
- a head comprising a slider and a transducer for writing data to and reading data from the disk;
- an actuator arm assembly for suspending the head adjacent to the disk, wherein rotation of the disk causes air to engage the slider to create a flying height gap at a head/disk interface between the head and the disk;
- an AC power source coupled to the head and the disk for generating an AC exciter signal across the flying height gap;
- and
- a capacitance sense circuit for sensing a head/disk capacitance at the head/disk interface in response to the AC exciter signal,
- wherein movement of the disk relative to the head causes air to engage the slider to form an air bearing system that forces the head away from the disk to create the flying height gap at the head/disk interface;
- and a frequency of the AC exciter signal is offset from a natural oscillating frequency associated with the air bearing system.
5 more elements
A disk drive, comprising:
- a disk for storing information;
- a head comprising a slider and a transducer for writing data to and reading data from the disk;
- an actuator arm assembly for suspending the head adjacent to the disk, wherein rotation of the disk causes air to engage the slider to create a flying height gap at a head/disk interface between the head and the disk;
- an AC power source coupled to the head and the disk for generating an AC exciter signal across the flying height gap;
- and
- a flying height control circuit for controlling the AC power source to generate the AC exciter signal to alter an attraction force between the head and the disk, thereby altering a flying height of the head relative to the disk, wherein a frequency of the AC exciter signal is offset from a data band defined by transmission of data to and from the transducer.
3 more elements
A disk drive, comprising:
- a disk for storing information;
- a head comprising a slider and a transducer for writing data to and reading data from the disk;
- an actuator arm assembly for suspending the head adjacent to the disk;
- a spindle motor for rotating the disk to cause air to engage the slider to form an air bearing system that forces the head away from the disk to form a flying height gap at a head/disk interface between the head and the disk;
- and
- an AC power source coupled to the head and the disk for establishing an AC exciter signal across the flying height gap, wherein a frequency of the AC exciter signal is offset from a data band defined by transmission of data to and from the transducer.
3 more elements
A method for operating a disk drive, wherein the disk drive comprises a disk for storing information, a head comprising a slider and a transducer for writing data to and reading data from the disk, and an AC power source coupled to the head and the disk, the method comprising the steps of:
- suspending the head relative to the disk;
- rotating the disk to cause air to engage the slider to create a flying height gap at a head/disk interface between the head and the disk;
- generating an AC exciter signal across the flying height gap using the AC power source, wherein a frequency of the AC exciter signal is offset from a data band defined by transmission of data to and from the transducer;
- and
- controlling the AC exciter signal to alter an attraction force between the head and the disk.
2 more elements
A method for operating a disk drive, wherein the disk drive comprises a disk for storing information, a head comprising a slider and a transducer for writing data to and reading data from the disk, and an AC power source coupled to the head and the disk, the method comprising the steps of:
- suspending the head adjacent to the disk;
- rotating the disk to cause air to engage the slider to form an air bearing system that forces the head away from the disk to form a flying height gap at a head/disk interface between the head and the disk;
- and
- establishing an AC exciter signal across the flying height gap using the AC power source, wherein a frequency of the AC exciter signal is offset from a data band defined by transmission of data to and from the transducer.
1 more element
A disk drive, comprising:
- a disk for storing information;
- a head comprising a slider and a transducer for writing data to and reading data from the disk;
- an actuator arm assembly for suspending the head adjacent to the disk, wherein rotation of the disk causes air to engage the slider to create a flying height gap at a head/disk interface between the head and the disk;
- an AC power source coupled to the head and the disk for generating an AC exciter signal across the flying height gap, wherein the AC exciter signal reduces electrostatic change at the head/disk interface;
- and
- a capacitive coupler electrically connected between the AC power source and the head, wherein the capacitive coupler includes a first coupler plate mounted on the actuator arm assembly and a second coupler plate mounted on the head.
3 more elements
A disk drive, comprising:
- a disk for storing information;
- a head comprising a slider and a transducer for writing data to and reading data from the disk;
- an actuator arm assembly for suspending the head adjacent to the disk, wherein rotation of the disk causes air to engage the slider to create a flying height gap at a head/disk interface between the head and the disk;
- an AC power source coupled to the head and the disk for generating an AC exciter signal across the flying height gap, wherein the AC exciter signal reduces electrostatic charge at the head/disk interface;
- a flying height control circuit for controlling the AC power source to generate the AC exciter signal to alter an attraction force between the head and the disk in response to a flying height signal, thereby altering a flying height of the head relative to the disk and maintaining the flying height within a range of acceptable flying heights;
- and
- a capacitive coupler electrically connected between the AC power source and the head that prevents a direct galvanic connection between the AC power source and the head, wherein the capacitive coupler includes a first coupler plate mounted on the actuator arm assembly and a second coupler plate mounted on the head.
4 more elements
A disk drive, comprising:
- a disk for storing information;
- a head suspended adjacent to the disk such that a flying height gap exist at a head/disk interface between the head and the disk, wherein the head comprises a transducer for writing data to and reading data from the disk;
- an AC power source for generating an AC exciter signal, wherein the AC power source is coupled to the head and the disk such that the AC exciter signal is present across the flying height gap;
- and
- a flying height control circuit for controlling the AC power source to generate the AC exciter signal to alter an attraction force between the head and the disk, wherein the flying height control circuit controls the AC power source to alter a duty cycle of the AC exciter signal to alter the attraction force between the head and the disk.
2 more elements
A disk drive, comprising:
- a disk for storing information;
- a head suspended adjacent to the disk such that a flying height gap exists at a head/disk interface between the head and the disk, wherein the head comprises a slider and a transducer for writing data to and reading data from the disk, and movement of the disk relative to the head causes air to engage the slider to form an air bearing system that forces the head away from the disk to create the flying height gap at the head/disk interface;
- and
- an AC power source for generating an AC exciter signal, wherein the AC power source is coupled to the head and the disk such that the AC exciter signal is present across the flying height gap and a frequency of the AC exciter signal is offset from a natural oscillating frequency associated with the air bearing system.
1 more element
A disk drive, comprising:
- a disk for storing information;
- a head suspended adjacent to the disk such that a flying height gap exists at a head/disk interface between the head and the disk, wherein the head comprises a transducer for writing data to and reading data from the disk;
- and
- an AC power source for generating an AC exciter signal, wherein the AC power source is coupled to the head and the disk such that the AC exciter signal is present across the flying height gap and a frequency of the AC exciter signal is offset from a data band defined by transmission of data to and from the transducer.
1 more element
A disk drive, comprising:
- a disk for storing information;
- a head suspended adjacent to the disk such that a flying height gap exists at a head/disk interface between the head and the disk, wherein the head comprises a transducer for writing data to and reading data from the disk;
- and
- an AC power source for generating an AC exciter signal, wherein the AC power source is coupled to the head and the disk such that the AC exciter signal is present across the flying height gap, a shape of the AC exciter signal is selected from the group consisting of substantially square, substantially trapezoidal, and substantially sinusoidal and a duty cycle of the AC exciter signal is approximately fifty percent.
1 more element
A disk drive, comprising:
- a disk for storing information;
- a head comprising a slider and a transducer for writing data to and reading data from the disk;
- an actuator arm assembly for suspending the head adjacent to the disk;
- a spindle motor for rotating the disk to cause air to engage the slider to form an air bearing system that forces the head away from the disk to form a flying height gap at a head/disk interface between the head and the disk;
- and
- an AC power source coupled to the head and the disk for establishing an AC exciter signal across the flying height gap, wherein a DC offset of the AC exciter signal alters an attraction force between the head and the disk.
3 more elements
A disk drive, comprising:
- a disk for storing information;
- a head comprising a slider and a transducer for writing data to and reading data from the disk;
- an actuator arm assembly for suspending the head adjacent to the disk, wherein rotation of the disk causes air to engage the slider to create a flying height gap at a head/disk interface between the head and the disk;
- and
- an AC power source coupled to the head and the disk for generating an AC exciter signal across the flying height gap, wherein the AC exciter signal reduces electrostatic charge at the head/disk interface and includes a DC offset.
2 more elements
A disk drive, comprising:
- a disk for storing information;
- a head comprising a slider and a transducer for writing data to and reading data from the disk;
- an actuator arm assembly for suspending the head adjacent to the disk, wherein rotation of the disk causes air to engage the slider to create a flying height gap at a head/disk interface between the head and the disk;
- and
- an AC power source coupled to the head and the disk for generating an AC exciter signal across the flying height gap, wherein the AC exciter signal reduces electrostatic charge at the head/disk interface and has a frequency that is tuned to a capacitance of the head/disk interface.
2 more elements
A disk drive, comprising:
- a disk for storing information;
- a head comprising a slider and a transducer for writing data to and reading data from the disk;
- an actuator arm assembly for suspending the head adjacent to the disk, wherein rotation of the disk causes air to engage the slider to create a flying height gap at a head/disk interface between the head and the disk;
- and
- an AC power source coupled to the head and the disk for generating an AC exciter signal across the flying height gap, wherein the AC exciter signal reduces electrostatic charge at the head/disk interface and has a frequency that is offset from a data band defined by transmission of data to and from the transducer.
2 more elements
A disk drive, comprising:
- a disk for storing information;
- a head comprising a slider and a transducer for writing data to and reading data from the disk;
- an actuator arm assembly for suspending the head adjacent to the disk, wherein rotation of the disk causes air to engage the slider to create a flying height gap at a head/disk interface between the head and the disk;
- and
- an AC power source coupled to the head and the disk for generating an AC exciter signal across the flying height gap, wherein the AC exciter signal reduces electrostatic charge at the head/disk interface and has a duty cycle that is based on a characteristic of the disk drive.
2 more elements
A disk drive, comprising:
- a disk for storing information;
- a head comprising a slider and a transducer for writing data to and reading data from the disk;
- an actuator arm assembly for suspending the head adjacent to the disk, wherein rotation of the disk causes air to engage the slider to form an air bearing system that frees the head away from the disk to create a flying height gap at a head/disk interface between the head and the disk;
- and
- an AC power source coupled to the head and the disk for generating an AC exciter signal across the flying height gap, wherein the AC exciter signal reduces electrostatic charge at the head/disk interface and damps oscillations of the air bearing system.
2 more elements
A disk drive, comprising:
- a disk for storing information;
- a head comprising a slider and a transducer for writing data to and reading data from the disk;
- an actuator arm assembly for suspending the head adjacent to the disk, wherein rotation of the disk causes air to engage the slider to form an air bearing system that forces the head away from the disk to create a flying height gap at a head/disk interface between the head and the disk;
- and
- an AC power source coupled to the head and the disk for generating an AC exciter signal across the flying height gap, wherein the AC exciter signal reduces electrostatic charge at the head/disk interface and has a frequency that is offset from a natural oscillating frequency associated with the air bearing system.
2 more elements
A disk drive, comprising:
- a disk for storing information;
- a head comprising a slider and a transducer for writing data to and reading data from the disk;
- an actuator arm assembly for suspending the head adjacent to the disk, wherein rotation of the disk causes air to engage the slider to form an air bearing system that forces the head away from the disk to create a flying height gap at a head/disk interface between the head and the disk;
- an AC power source coupled to the head and the disk for generating an AC exciter signal across the flying height gap, wherein the AC exciter signal reduces electrostatic charge at the head/disk interface and has a frequency that is tuned to a capacitance of the head/disk interface, offset from a data band defined by transmission of data to and from the transducer, and offset from a natural oscillating frequency associated with the air bearing system;
- and
- a flying height control circuit for controlling the AC power source to generate the AC exciter signal to alter an attraction force between the head and the disk in response to a flying height signal, thereby altering a flying height of the head relative to the disk and maintaining the flying height within a range of acceptable flying heights.
3 more elements
A disk drive, comprising:
- a disk for storing information;
- a head suspended adjacent to the disk such that a flying height gap exists at a head/disk interface between the head and the disk, wherein the head comprises a transducer for writing data to and reading data from the disk;
- an AC power source for generating an AC exciter signal, wherein the AC power source is coupled to the head and the disk such that the AC exciter signal is present across the flying height gap;
- and
- a flying height control circuit for controlling the AC power source to generate the AC exciter signal to alter an attraction force between the head and the disk, wherein the flying height control circuit controls the AC power source to increase a duty cycle of the AC exciter signal in response to electrostatic charge at the head/disk interface to discharge the electrostatic charge at the head/disk interface.
2 more elements
A disk drive, comprising:
- a disk for storing information;
- a head comprising a slider and a transducer for writing data to and reading data from the disk;
- an actuator arm assembly for suspending the head adjacent to the disk, wherein rotation of the disk causes air to engage the slider to create a flying height gap at a head/disk interface between the head and the disk;
- an AC power source coupled to the head and the disk for generating an AC exciter signal across the flying height gap;
- and
- a capacitance sense circuit for sensing a head/disk capacitance at the head/disk interface in response to the AC exciter signal, the capacitance sense circuit comprises a sense resistor electrically connected in parallel with the head/disk interface;
- and a current detect circuit for detecting a sense current through the sense resistor.
4 more elements
Dependencies are inferred from the claim text.