Patent classifications
G11B5/6076
Data storage device with adaptive write policy and enhanced longevity
Illustrative aspects are directed to a data storage device comprising one or more disks; an actuator mechanism comprising one or more heads, and configured to position a head proximate to a disk surface; and one or more processing devices. The one or more processing devices are configured to: measure a read quality of a location on the disk surface; modify a refresh frequency for performing refresh writes at the location, based on the read quality at the location; in response to the refresh frequency at the location becoming stabilized, determine an integrated track interference (xTI) per write metric at the location; and, in response to determining that the xTI per write metric at the location is below a threshold for the xTI per write metric, modify an operating parameter of the head at the location to improve a longevity metric.
MAGNETIC DISK DEVICE
According to one embodiment, a magnetic disk device includes a rotatable disk-shaped recording medium, a magnetic head including a write head having a main magnetic pole that applies a recording magnetic field to the recording medium, an assist element that assists magnetic recording by the main magnetic pole, and a plurality of thermal actuators that control a head gradient with respect to the recording medium, and a controller which includes a detection unit configured to detect deterioration of the magnetic head, and changes a head gradient of the magnetic head by the thermal actuator according to the detected deterioration.
Magnetic disk device
According to one embodiment, a magnetic disk device includes a rotatable disk-shaped recording medium, a magnetic head including a write head having a main magnetic pole that applies a recording magnetic field to the recording medium, an assist element that assists magnetic recording by the main magnetic pole, and a plurality of thermal actuators that control a head gradient with respect to the recording medium, and a controller which includes a detection unit configured to detect deterioration of the magnetic head, and changes a head gradient of the magnetic head by the thermal actuator according to the detected deterioration.
Bond pad sharing between a temporary contact sensor and a multiplicity of readers of a recording head
A slider of a magnetic recording head includes a plurality of electrical bond pads and a plurality of readers comprising at least a first reader and a second reader. Each of the readers is coupled to a different pair of electrical bond pads. A temporary contact sensor is provided on the slider and coupled between a bond pad of the first reader and a bond pad of the second reader. The temporary contact sensor is configured for operation during a certification process of the apparatus and to become inoperable after completion of the certification process.
Bond pad sharing for powering a multiplicity of electrical components of a recording head
A slider of a magnetic recording head comprises a plurality of electrical bond pads coupled to bias sources and a ground pad. Each of a plurality of electrical components of the slider is coupled one or more of the electrical bond pads, wherein at least one of the electrical bond pads is a shared electrical bond pad coupled to at least a first electrical component and a second electrical component. A switching transistor is coupled to the first and second components and the ground pad. The switching transistor is arranged to control powering of the second component in response to biasing of the first component.
Thin Film Magnetic Head, Head Gimbals Assembly, Head Arm Assembly, And Magnetic Disk Unit
This thin film magnetic head includes a magnetic pole including an end surface exposed on an air bearing surface, and a contact detection section including a magnetic material layer provided near the air bearing surface, and a magnetic-domain stabilizing structure stabilizing a magnetic domain structure of the magnetic material layer.
High sample rate dPES to improve contact detection signal to noise ratio
Using a high sample rate dPES, together with pulsed heater and lock-in technique, to improve dPES SNR for contact detection between the head and media surface. Steps of powering a transducing head actuator with pulsed input signal at a select data track offset from a previously-written to data track of the storage medium, where the pulsed input signal has select amplitude and duty cycle to simulate a response signal, and further locking in an amplitude with respect to the heater frequency, can lead to a determination of level of heater power for initiating contact between the transducing head and the storage medium.
Pad sharing for contact sensor and bolometer with temperature compensation in heat-assisted magnetic recording device
A slider of a heat-assisted recording head comprises electrical bond pads coupled to bias sources and a ground pad, an air bearing surface, and a waveguide configured to receive light from a laser source. A contact sensor proximate the air bearing surface is coupled between a first bond pad and a second bond pad. A bolometer is coupled to a reference thermal sensor. The bolometer is situated at a slider location that receives at least some of the light communicated along the waveguide. The reference thermal sensor is situated at a slider location unexposed to the light communicated along the waveguide. The bolometer and reference thermal sensor are coupled between the first and second bond pads and in parallel with the contact sensor. A ground connection is coupled to the ground pad and at a connection between the bolometer and the reference thermal sensor.
Data storage device detecting minimum stable fly height of a head over a disk
A data storage device is disclosed comprising a head actuated over a disk, wherein the head comprises a fly height actuator (FHA). A FHA control signal is applied to the FHA, wherein the FHA control signal comprises a DC component and an AC component. A fly height metric is measured representing a fly height of the head over the disk for different levels of the DC component. A modulation amplitude of the fly height metric is detected, and a minimum in the modulation amplitude of the fly height metric is detected.
Contact induced data storage device destruction
A data storage device may be destroyed by suspending a transducing head above a data storage medium prior to inducing contact of the transducing head with a first layer of the data storage medium in response to a signal from a controller. Deflection of the transducing head can then be increased to penetrate to a destroy depth in a second layer of the data storage medium that is maintained while the data storage medium spins. The controller may then issue at least one data read command to access data from the data storage medium and when a data read error is received, the data storage medium and transducing head can be verified as destroyed and incapable of accessing data previously written to the data storage medium.