Abstract: The present disclosure generally relates to a multi-disk drive comprising a plurality of media surfaces and a plurality of heads, wherein a head of the plurality of heads is configured to be actuated over each surface of the plurality of media surfaces. The multi-disk drive further comprises control circuitry configured to write data to a first media surface of the plurality of media surfaces using a first head of the plurality of heads, and after all of an available memory of the first media surface has been filled, write data to a second media surface of the plurality of media surfaces using a second head of the plurality of heads. The control circuitry is further configured to permanently disable write access to one or more media surfaces of the plurality of media surfaces, while continuing to permit read access to the plurality of media surfaces.

Abstract: The present disclosure relates to pretreating a magnetic recording head. For a HAMR head, a NFT is present. Current can be applied to the NFT to condition the NFT. The current is applied in one of three ways: slowly ramping up the current from a starting level below a level capable of writing data to the optical laser current over a predetermined period of time, applying the current at a fixed value below the optical laser current for the predetermined period of time, or slowly ramping up the current from a starting level below a level capable of writing data to the optical laser current over the predetermined period of time while also intermittently removing the current. By conditioning the NFT in such a manner, the HAMR head can avoid thermal shock and thermal fatigue and thus increase the lifetime of the magnetic media drive.

Abstract: The present disclosure generally relates to a tape drive having a regenerative braking system. The tape drive comprises a first reel; a first spindle coupled to the first reel; a first motor coupled to the first spindle, wherein the first motor is configured to rotate the first spindle; a second reel; a second spindle coupled to the second reel; a second motor coupled to the second spindle, wherein the second motor is configured to rotate the second spindle; and a regenerative braking circuit coupled to the first motor and the second motor, wherein during a braking of the motors, the regenerative braking circuit and the motors convert a mechanical energy of the motors to electrical energy for a power storage mechanism, thereby providing resistance to the rotation of the spindles.

Abstract: The present disclosure generally relate to tape assembly implementations for magnetic recording devices, such as tape embedded drives (TEDs). In one or more embodiments, a first reel and a second reel are mounted at stationary positions. One or more of the first reel and/or the second reel includes a hub mounted to a spindle, and a single flange extending relative to the hub. In one or more embodiments, one or more of a first reel and/or a second reel each includes a flangeless hub mounted to a spindle.

Abstract: The present disclosure generally relates to a multi-disk drive comprising a plurality of media surfaces and a plurality of heads, wherein a head of the plurality of heads is configured to be actuated over each surface of the plurality of media surfaces. The multi-disk drive further comprises control circuitry configured to write data to a first media surface of the plurality of media surfaces using a first head of the plurality of heads, and after all of an available memory of the first media surface has been filled, write data to a second media surface of the plurality of media surfaces using a second head of the plurality of heads. The control circuitry is further configured to permanently disable write access to one or more media surfaces of the plurality of media surfaces, while continuing to permit read access to the plurality of media surfaces.

Abstract: Example preamplifier circuits, data storage devices, and methods to provide a preamplifier circuit with separate read and write power channels are described. The preamplifier circuit may include a write driver circuit configured to send a write signal to a writer element of a data storage device and a read driver circuit configured to receive a read signal from a reader element of the data storage device. The write driver circuit may receive a write power signal through a write power channel of a bus interface and the read driver circuit may receive a read power signal through a read power channel of the bus interface, where the write power signal and the read power signal are different. In some configurations, the different read and write power signals may be received from a switching regulator on the printed circuit board that mounts other data storage device electronics, such as the drive controller circuit and/or read/write channel circuit.

Abstract: Example systems, data storage devices, and methods to provide long-term spacing compensation for heat assisted magnetic recording are described. The data storage device includes a storage medium with data tracks and a head that can be positioned for reading and writing those tracks. The head includes a laser for heat assisted magnetic recording and a fly height actuator. Based on the operation of the laser, both a short-term fly height compensation parameter and a long-term fly height compensation parameter are determined based on different temperature state models. The operating power of the fly height actuator is determined, at least in part, based on the short-term and long-term height compensation parameters.

Abstract: Various apparatuses, systems, methods, and media are disclosed to provide a heat-assisted magnetic recording (HAMR) medium that has a media carbon dual-layer media carbon overcoat with both a carbon layer and a carbon-nitrogen (CN) layer. The carbon layer may be a plasma enhanced chemical vapor deposition (PECVD) carbon layer and the CN layer may be a sputtered CN layer. The dual-layer media carbon overcoat helps reduce a laser power requirement of an HAMR disk drive system and thus reduce the operating temperature of a near field transducer (NFT) of a HAMR disk drive. The dual-layer overcoat can also improve thermal and thermo-oxidative stability of the media and help retain a lubricant provided on the overcoat, therefore improving HAMR head-media interface reliability. The dual-layer media carbon overcoat can also reduce carbonaceous smear within a head-media gap.

Abstract: The present disclosure generally relates to using a data timestamp and/or a read counter to prevent data from being re-read and signal that the data has been accessed. The write assist element in the write head can be utilized to degrade the data or an allocated marker after the data has been read. The degradation functions as a read counter to indicate how many times the data has been read. Additionally and/or alternatively, a timestamp can be utilized. The timestamp is updated each time that the data has been accessed. In so doing, it is possible to determine whether data in a data storage device has been accessed.

Abstract: Example preamplifier circuits, data storage devices, and methods to provide a preamplifier circuit with separate read and write power channels are described. The preamplifier circuit may include a write driver circuit configured to send a write signal to a writer element of a data storage device and a read driver circuit configured to receive a read signal from a reader element of the data storage device. The write driver circuit may receive a write power signal through a write power channel of a bus interface and the read driver circuit may receive a read power signal through a read power channel of the bus interface, where the write power signal and the read power signal are different. In some configurations, the different read and write power signals may be received from a switching regulator on the printed circuit board that mounts other data storage device electronics, such as the drive controller circuit and/or read/write channel circuit.

Abstract: The present disclosure generally relates to tape assembly implementations for magnetic recording devices, such as tape embedded drives (TEDs). In one or more embodiments, one or more of a first reel and/or a second reel is laterally movable relative to a side wall of a casing of the tape assembly. In one or more embodiments, a drive assembly laterally moves the first reel and the second reel substantially simultaneously such that a spindle distance between a first spindle and a second spindle is substantially constant.

Abstract: The present disclosure relates to pretreating a magnetic recording head. For a HAMR head, a NFT is present. Current can be applied to the NFT to condition the NFT. The current is applied in one of three ways: slowly ramping up the current from a starting level below a level capable of writing data to the optical laser current over a predetermined period of time, applying the current at a fixed value below the optical laser current for the predetermined period of time, or slowly ramping up the current from a starting level below a level capable of writing data to the optical laser current over the predetermined period of time while also intermittently removing the current. By conditioning the NFT in such a manner, the HAMR head can avoid thermal shock and thermal fatigue and thus increase the lifetime of the magnetic media drive.

Abstract: The present disclosure relates to pretreating a magnetic recording head. For a HAMR head, a NFT is present. Current can be applied to the NFT to condition the NFT. The current is applied in one of three ways: slowly ramping up the current from a starting level below a level capable of writing data to the optical laser current over a predetermined period of time, applying the current at a fixed value below the optical laser current for the predetermined period of time, or slowly ramping up the current from a starting level below a level capable of writing data to the optical laser current over the predetermined period of time while also intermittently removing the current. By conditioning the NFT in such a manner, the HAMR head can avoid thermal shock and thermal fatigue and thus increase the lifetime of the magnetic media drive.

Abstract: A heat-assisted magnetic recording (HAMR) hard disk drive has a gas-bearing slider supporting a near-field transducer (NFT) and a NFT temperature sensor (NTS). An optional first IVC circuitry may provide a bias voltage to the slider body to assure substantially zero electrical potential between the slider body and the disk to minimize slider-disk contact and lubrication pick-up. A second IVC circuitry operates independently of the first IVC circuitry and provides a negative bias voltage to the NTS (and the connected NFT) relative to the disk to minimize the adverse effects of excessive heating on the NFT.

Abstract: A data storage device is disclosed comprising a head actuated over a disk surface, wherein the head comprises a plurality of elements including a write assist element. A bias signal applied to the write assist element is controlled such that the write assist element is substantially unprotruded, and while the write element is substantially unprotruded, an air bearing resonant frequency (ABRF) of the head and disk surface is measured. The bias signal applied to the write assist element is controlled such that the write assist element protrudes toward the disk surface, and while the write assist element protrudes toward the disk surface, the head is excited at the measured ABRF and the head touching down onto the disk surface is detected.

Abstract: A data storage device is disclosed comprising a head actuated over a disk, wherein the head comprises a write assist element. Data is written to the disk using the write assist element. A protrusion of the head toward the disk is measured periodically, and an abnormality with the write assist element is detected when a slope of the protrusion measurements indicates the protrusion is increasing.

Abstract: A hard disk drive has a gas-bearing slider supporting a write head with an electrically conductive structure, like a spin-torque oscillator (STO), in the write gap, and dual independent interface voltage control (IVC) circuitry coupled to elements on the slider. A first IVC circuitry provides a bias voltage to the slider body to assure substantially zero electrical potential between the slider body and the disk to minimize slider-disk contact and lubrication pick-up. A second IVC circuitry operates independently of the first IVC circuitry and provides a bias voltage to the electrically conductive structure region to assure a negative potential of the electrically conductive structure region relative to the disk to minimize degradation of the slider overcoat and thus oxidation of the electrically conductive structure.

Abstract: Embodiments disclosed herein generally relate to a method for monitoring optical power in a HAMR device. In one embodiment, the method includes enhancing a thermal sensor bandwidth through advanced electrical detection techniques. The advanced electrical detection techniques include obtaining calibration waveform data for a thermal sensor by calibrating the thermal sensor, obtaining real-time waveform data for the thermal sensor that may deviate from the calibration waveform data, updating the calibration waveform data to include the real-time waveform data, repeating obtaining real-time waveform data and updating the calibration waveform data during writing operations. By updating the calibration waveform data, the bandwidth of the thermal sensor is determined by a fixed sampling time interval, and the thermal sensor rise time to steady state would not be a limitation to its response time.

Abstract: Disclosed herein is a magnetic storage device that comprises a housing defining an interior cavity. The magnetic storage device also comprises at least one magnetic disk in the interior cavity of the housing. The magnetic storage device further comprises at least one read-write head in the interior cavity and configured to read data from and write data to the magnetic disk. The read-write head comprises a heat-assisted magnetic storage (HAMR) head. The magnetic storage device additionally comprises a gas, comprising oxygen and helium, sealed in the interior cavity of the housing. A percent concentration of oxygen in the gas is greater than or equal to 3%. A pressure of the gas is between 10% and 70%, inclusive, of atmospheric pressure. A relative humidity within the interior cavity is less than 5%, inclusive. A percent concentration of helium in the gas is less than or equal to 90%.

Abstract: A method and system for determining slider-disk contact in a hard-disk drive (HDD) that has dual independent heaters for thermal fly-height control, and dual embedded contact sensors, includes dithering power to the two heaters at different frequencies. The HDD has the two contact sensors electrically connected to provide a single combined output signal in response to the dithering. The single combined output signal is analyzed to detect two signals at the two different frequencies. When either detected signal exceeds a predetermined touchdown threshold value, the values of heater power for the two heaters are recorded, indicating that that combination of heater power values corresponds to slider-disk contact.