Patent classifications
G11B5/6017
Active control of a read/write head for reduced head-media spacing
The invention generally relates to a system for achieving reduced head-media spacing (HMS) in a hard disk drive (HDD) by providing active control over the positioning of a read/write head relative to a rotating magnetic data recording and reading surface of a disk. The system is configured to monitor and adjust positioning of the read/write head in real, or near-real time during disk rotation to maintain the HMS between a magnetic transducer of the read/write head and the disk surface within a defined range, generally between 1.0 nm and 10.0 nm, and, in some embodiments, approximately 4.3 nm. The system replaces the conventional an air bearing surface (ABS) design with a fully active suspension to maintain the head flying height within the desired range. The system further allows for each of the magnetic transducer and disk surface to be to be devoid of any overcoat or lubricant layers.
SYSTEM AND METHOD FOR DISK DRIVE FLY HEIGHT MEASUREMENT
A system for determining a fly height includes a first head of a disk drive, a second head of the disk drive, a capacitive sensor circuit coupled to the first head and the second head, and a logic device coupled to the capacitive sensor circuit. The capacitive sensor circuit is configured to measure a first capacitance between the first head and the first disk, remove noise from the first capacitance using a second capacitance between the second head and the second disk, and based thereon determine a corrected first capacitance. The logic device is configured to determine the fly height between the first head and the first disk using the corrected first capacitance.
Active control of a read/write head for reduced head-media spacing
The invention generally relates to a system for achieving reduced head-media spacing (HMS) in a hard disk drive (HDD) by providing active control over the positioning of a read/write head relative to a rotating magnetic data recording and reading surface of a disk. The system is configured to monitor and adjust positioning of the read/write head in real, or near-real time during disk rotation to maintain the HMS between a magnetic transducer of the read/write head and the disk surface within a defined range, generally between 1.0 nm and 10.0 nm, and, in some embodiments, approximately 4.3 nm. The system replaces the conventional an air bearing surface (ABS) design with a fully active suspension to maintain the head flying height within the desired range. The system further allows for each of the magnetic transducer and disk surface to be to be devoid of any overcoat or lubricant layers.
SLIDER TRAILING EDGE CONTAMINATION SENSOR
A slider of a magnetic recording head has a leading edge, a trailing edge, and an air bearing surface between the leading and trailing edges. A sensor is situated at the trailing edge of the slider and configured to sense presence of a lube droplet or other contaminant at the trailing edge.
Concurrent modulation and frictional heating head disk contact detection
An apparatus comprises a heat-assisted magnetic recording (HAMR) head, a sensor, and a controller. The HAMR head is configured to interact with a magnetic storage medium. The sensor is configured to produce a signal indicating the occurrence of head-medium contact. The controller is configured to receive the signal and concurrently determine from the signal if the occurrence of head-medium contact is caused by a first contact detection parameter, a second contact detection parameter, or both the first and second contact detection parameters.
Head Gimbal Assembly Height Determination with Charge-to-Voltage Converter
A circuit for determining head gimbal assembly (HGA) height is provided. The circuit includes a first switch configured to be controlled by a first clock signal, an amplifier, and a first capacitor coupled to the first switch, wherein the first capacitor is formed by at least part of a head gimbal assembly and a storage media. The circuit further includes a second capacitor coupled to an input of the amplifier, and an output of the amplifier, wherein the second capacitor is configured to store a charge from the first capacitor over one or more cycles of the first clock signal. The amplifier is configured to generate an output voltage based, at least in part, on a change in the capacitance of the first capacitor over the one or more cycles of the first clock signal.
SYSTEM AND METHOD FOR DISK DRIVE FLY HEIGHT MEASUREMENT
A method for determining a fly height includes measuring a first differential voltage between a first head of a disk drive and a reference voltage with a first front end circuit, converting the first differential voltage to a first analog current signal with the first front end circuit, and converting the first analog current signal to a second differential voltage with a first back end circuit. The first front end circuit is coupled with the first head. The first back end circuit is coupled with the first front end circuit. The method further includes determining a first capacitance between the first head and a first disk of the disk drive based on the second differential voltage and determining the fly height between the first head and the first disk using the first capacitance.
Head gimbal assembly height determination with charge-to-voltage converter
A circuit for determining head gimbal assembly (HGA) height is provided. The circuit includes a first switch configured to be controlled by a first clock signal, an amplifier, and a first capacitor coupled to the first switch, wherein the first capacitor is formed by at least part of a head gimbal assembly and a storage media. The circuit further includes a second capacitor coupled to an input of the amplifier, and an output of the amplifier, wherein the second capacitor is configured to store a charge from the first capacitor over one or more cycles of the first clock signal. The amplifier is configured to generate an output voltage based, at least in part, on a change in the capacitance of the first capacitor over the one or more cycles of the first clock signal.
System and method for disk drive fly height measurement
A method for determining a fly height includes measuring a first differential voltage between a first head of a disk drive and a reference voltage with a first front end circuit, converting the first differential voltage to a first analog current signal with the first front end circuit, and converting the first analog current signal to a second differential voltage with a first back end circuit. The first front end circuit is coupled with the first head. The first back end circuit is coupled with the first front end circuit. The method further includes determining a first capacitance between the first head and a first disk of the disk drive based on the second differential voltage and determining the fly height between the first head and the first disk using the first capacitance.