56results about "Special recording techniques" patented technology

According to one embodiment, a method of adjusting a heat assisted magnetic recording and reproducing device maintains a heat assisted magnetic recording head of the heat assisted magnetic recording and reproducing device in an on-track state, maintains a recording current for data recording below a threshold value, and applies a light source drive current emitting light to a light source.

According to one embodiment, a magnetic head includes a first magnetic pole, a second magnetic pole, and a magnetic element provided between the first and the second magnetic poles. The magnetic element includes first to fourth magnetic layers, and first to fifth non-magnetic layers. The fourth magnetic layer includes a first element and at least one of Fe, Co or Ni. The first element including at least one selected from the group consisting of Cr, V, Mn, Ti, N and Sc. The fourth non-magnetic layer including at least one selected from the group consisting of Cu, Au, Cr, Al, V and Ag. The fifth non-magnetic layer includes at least one selected from the group consisting of Cu, Au, Cr, Al, V and Ag.

According to one embodiment, a magnetic head includes a first magnetic pole, a second magnetic pole, and a magnetic element provided between the first and the second magnetic poles. The magnetic element includes first to fifth magnetic layers, and first to sixth non-magnetic layers. The sixth non-magnetic layer is provided between the fifth magnetic layer and the second magnetic pole. The sixth non-magnetic layer includes at least one selected from the group consisting of Ru, Ir, Ta, Rh, Pd, Pt and W.

According to one embodiment, a magnetic recording device includes a magnetic recording medium, a plurality of magnetic heads for recording information on the magnetic recording medium, and a controller for controlling the magnetic heads. Each of the magnetic heads includes a coil, a first magnetic pole for generating a magnetic field according to a recording current supplied to the coil, and a light emitting section for irradiating the magnetic recording medium with light to locally increase a temperature of the magnetic recording medium. The controller performs a first operation, in which a lifetime information related to a remaining life time of one of the magnetic heads is calculated based on a first information related to a failure probability of a magnetic head group including the magnetic heads and a second information related to a remaining time based on a history of the one of the magnetic heads.

To provide a ferroelectric storage device capable of stabilizing a torque of a ferroelectric recording medium drive unit even when used for a long time and suppressing a decrease in continuity in the ferroelectric recording medium drive unit.SOLUTION: A ferroelectric storage device according to the present invention includes a ferroelectric recording medium, a conductive probe, a probe slider, and a ferroelectric recording medium drive unit. The ferroelectric recording medium drive unit has a bearing sleeve inside a housing and a conductive shaft member inserted into an inner peripheral surface of the bearing sleeve, a gap between the inner peripheral surface of the bearing sleeve and an outer peripheral surface of the shaft member contains lubricating oil that generates pressure by dynamic pressure to support the shaft member in a radial direction in a non-contact manner, the housing has a conductive housing bottom portion that faces the shaft end of the shaft member, a convex or concave spherical surface is included on at least one of the shaft end portions of the shaft member and the bottom portion of the housing, and the lubricating oil contains a conductive powder containing an inorganic material.SELECTED DRAWING: Figure 8

A data storage device comprises a magnetic medium and a head configured to be actuated over the magnetic medium. The head comprises a write element and a write driver configured to generate a write current to be applied to the write element. The write driver comprises a data switch section configured to switchably output low-level signals and high-level signals, and a stationary cascode section configured to receive the low-level signals and high-level signals from the data switch section and to generate a cascode pass through current. The data switch section comprises low voltage CMOS devices and the stationary cascode section comprises high voltage CMOS devices.

To provide a ferroelectric storage device, a method for reading information in the ferroelectric storage device, and a method for writing and reading information in the ferroelectric storage device that can read information stored in a ferroelectric recording medium at a high speed.SOLUTION: A ferroelectric storage device according to the present invention comprises: a ferroelectric recording medium that has a ferroelectric layer; a conductive probe; a probe slider; a ferroelectric recording medium driving unit; and a recording reproduction signal processing unit that is connected with the conductive probe and performs processing on an information writing signal and an information reading signal. In detecting an electric charge on the ferroelectric layer, the recording reproduction signal processing unit applies positive and negative bias voltages to the conductive probe, and measures a tunnel current flowing between the conductive probe and the ferroelectric layer to detect the electric charge on the ferroelectric layer.SELECTED DRAWING: Figure 10

The present disclosure describes aspects of a differential current-mode (iMode) driver for microwave-assisted magnetic recording (MAMR) application in hard-disk drives. In some aspects, an iMode driver circuitry employs a driver circuit coupled to power supply connections. The driver circuit is configured to provide a controlled differential bias current and includes separate source and sink output terminals. A MAMR sensor couples between the source and sink output terminals, through which the MAMR sensor receives the controlled differential bias current provided by the driver circuit. The MAMR sensor, which has a field-entry terminal and a field-exit terminal, generates microwave fields for the recording process. A common-mode feedback (CMFB) loop couples to the field-entry and field-exit terminals of the MAMR sensor, forming a feedback pathway with the driver circuit. This CMFB loop detects common-mode voltage (CMV) and adjusts the controlled differential bias current to maintain CMV regulation of the MAMR sensor.

A ferroelectric recording medium includes an electrode layer, a ferroelectric recording layer, and a protection layer formed in this order on a substrate, wherein the ferroelectric recording layer includes a ferroelectric layer, and a lattice constant of a material constituting the ferroelectric layer and a lattice constant of a material constituting the electrode layer or the substrate are lattice-matched within a range of ±10%.

The present disclosure provides a magnetic recording device capable of improving recording density. According to one embodiment, a magnetic recording apparatus includes a magnetic head and a magnetic recording medium. The magnetic head includes a first magnetic pole, a second magnetic pole, and a magnetic element provided between the first magnetic pole and the second magnetic pole. The magnetic element includes a first magnetic layer and a second magnetic layer. The magnetic element includes a midpoint between the first magnetic layer and the second magnetic layer in a first direction from the first magnetic pole toward the second magnetic pole. The first ratio (r1) and the second ratio (r2) satisfy-0.26 * r1 + 0.60 < = r2 < =-0.26 * r2 + 0.70. The first ratio (r1) is the ratio of a second distance (L2) between the first magnetic pole and the midpoint to a first distance (L1) between the first magnetic pole and the second magnetic pole. The second ratio (r2) is the ratio of the dynamic coercive force (Hc0) of the magnetic recording medium to the average anisotropic magnetic field (Hk).

To provide a magnetic recording device that enables improved recording density. [Solution] According to the embodiment, the magnetic recording device includes a magnetic head and a control unit. The magnetic head includes first and second magnetic poles, a magnetic element, and a coil. The control unit is configured to switch between performing a first operation and a second operation. In the first operation, the control unit supplies a first recording element current to the magnetic element. In the second operation, the control unit supplies a second recording element current to the magnetic element. The first recording element current is less than or equal to a first current value. The second recording element current exceeds the first current value.

According to one embodiment, a magnetic recording device includes a magnetic head and a magnetic recording medium. The magnetic head includes a first magnetic pole, a second magnetic pole, and a magnetic element provided between the first magnetic pole and the second magnetic pole. The magnetic element includes a first magnetic layer, and a second magnetic layer provided between the first magnetic layer and the second magnetic pole. The magnetic element includes a midpoint between the first magnetic layer and the second magnetic layer in a first direction from the first magnetic pole to the second magnetic pole.

Disclosed are methods for linearizing the response of a non-linear magnetic reader, for example in the operation of a hard disk drive. Magnetic readers generally exhibit non-linearities in their response to an applied magnetic field, and those non-linearities may be particularly pronounced when the field strength is high. This deviation from linearity at larger field strengths can limit the useful range of field amplitudes. To expand the useful range of field amplitudes and thereby increase the available signal at the reader, the reader bias current may be varied in such a way to compensate for the natural non-linearity of the reader, thus making the reader output signal linear over a larger range of detected field strengths.

Various illustrative aspects are directed to a data storage device comprising a disk and a read / write head configured to read data from and write data to the disk. The read / write head comprises a write pole tip and a transducer configured near the write pole tip. One or more processing devices are mounted on or near the read / write head and generate an AC current that is applied to the transducer to cause the transducer to generate a high frequency auxiliary field that is applied to the disk. The one or more processing devices may be an RF source IC mounted on or near a slider on which the read / write head is integrated or mounted.

To provide a magnetic recording device that enables improved recording density. [Solution] According to the embodiment, the magnetic recording device includes a magnetic head and a control unit. The magnetic head includes first and second magnetic poles, a magnetic element, a coil, a first terminal, and a second terminal. The control unit is configured to perform a first operation. In the first operation, the control unit is configured to supply a recording element current to the magnetic element and a recording coil current to the coil. The absolute value of the recording coil current is less than or equal to the first coil current value corresponding to the first peak.

The present disclosure provides a magnetic recording device capable of improving recording density. According to one embodiment, a magnetic recording apparatus includes a magnetic head and a control unit. The magnetic head includes a first magnetic pole, a second magnetic pole, a magnetic element, a coil, a first terminal, and a second terminal. The control unit is configured to perform a first operation. In the first operation, the control unit supplies a recording-time element current to the magnetic element and supplies a recording-time coil current to the coil. The absolute value of the coil current during recording is equal to or less than a first coil current value corresponding to the first peak.

To provide a ferroelectric storage device that can read information stored in a ferroelectric recording medium at a high speed.SOLUTION: A ferroelectric storage device according to the present invention comprises: a ferroelectric recording medium; a conductive probe that performs writing and reading of information with respect to the ferroelectric recording medium; a probe slider that causes the conductive probe to move in a floating state on a surface of the ferroelectric recording medium; a ferroelectric recording medium driving unit that rotates the ferroelectric recording medium; and a recording reproduction signal processing unit that performs processing on an information writing signal and an information reading signal with the conductive probe. The recording reproduction signal processing unit detects a signal generated due to interatomic force between the conductive probe and the ferroelectric recording medium.SELECTED DRAWING: Figure 8

To provide a magnetic head and a magnetic recording device capable of improving recording density.SOLUTION: A magnetic head 110 includes first and second magnetic poles 31 and 32 and a laminate 20 provided between the first and second magnetic poles. The laminate includes: a first magnetic layer 21; a second magnetic layer 22 provided between the first magnetic layer and the second magnetic pole; a first non-magnetic layer 41 provided between the first magnetic layer and the second magnetic layer; a second non-magnetic layer 42 provided between the second magnetic layer and the second magnetic pole; and a third non-magnetic layer 43 provided between the first magnetic pole and the first magnetic layer. The first magnetic layer includes a first element containing at least one of Fe, Co, and Ni. The second magnetic layer includes the first element and a second element containing at least one selected from a group consisting of Cr, V, Mn, Ti, and Sc. The first magnetic layer does not include the second element. The first thickness of the first magnetic layer is equal to or more than 0.25 times and equal to or less than 4 times the second thickness of the second magnetic layer.SELECTED DRAWING: Figure 1

A read head includes a permanent magnet (PM) layer formed up to 100 nm behind a free layer where PM layer magnetization may be initialized in a direction that adjusts free layer (FL) bias point, and shifts sensor asymmetry (Asym) closer to 0% for individual heads at slider or Head Gimbal Assembly level to provide a significant improvement in device yield. Asym is adjusted using different initialization schemes and initialization directions. With individual heads, initialization direction is selected based on a prior measurement of asymmetry. The PM layer is CoPt or CoCrPt and has coercivity from 500 Oersted to 1000 Oersted. The PM layer may have a width equal to the FL, or in another embodiment, the PM layer adjoins a backside of the top shield and has a width equal to or greater than that of the FL.

The invention provides a magnetic recording device and a magnetic recording system capable of obtaining stable operation. According to one embodiment, a magnetic recording apparatus includes a magnetic recording medium, a plurality of magnetic heads, and a control unit. Each of the plurality of magnetic heads includes a coil, a first magnetic pole, and a light emitting portion. The control unit performs a first operation. In the first operation, the control unit calculates life information relating to a remaining life time of one of the plurality of magnetic heads on the basis of first information relating to a failure probability of a magnetic head group including the plurality of magnetic heads and second information relating to a remaining time based on a history of the one of the plurality of magnetic heads.

To provide a thermally assisted magnetic recording / reproducing device in which a lubricant hardened material is provided in advance near a near field optical element in a head while minimizing impact on areas other than an area where a lubricant hardened material is formed, and an adjustment method thereof.SOLUTION: An adjustment method of a thermally assisted magnetic recording / reproducing device according to the embodiment includes: maintaining a thermally assisted magnetic recording head of the thermally assisted magnetic recording / reproducing device on-track; maintaining a record current for data recording for the thermally assisted magnetic recording head that is less than a threshold value; and applying a light source drive current for light emission to a light source.SELECTED DRAWING: Figure 5

To provide a ferroelectric storage device capable of controlling a distance between a probe and a recording medium with high accuracy and high speed.SOLUTION: A ferroelectric storage device according to the present invention includes: a ferroelectric recording medium; a conductive probe; a probe slider; a piezoelectric element or an electrostrictive element which is provided on the probe slider and in which the conductive probe is connected so as to face the ferroelectric recording medium; and a control unit that controls a voltage applied to the piezoelectric element or the electrostrictive element to expand and contract the piezoelectric element or the electrostrictive element and adjusts a distance between the ferroelectric recording medium and the conductive probe. The control unit controls the voltage applied to the piezoelectric element or the electrostrictive element based on a read signal from the conductive probe to expand and contract the piezoelectric element or the electrostrictive element.SELECTED DRAWING: Figure 9

The embodiment provides a magnetic disk device and a read / write processing method capable of improving recording density. The magnetic disk device of the embodiment comprises: a disk; a head for writing data to the disk and reading data from the disk; and a controller for setting different rewrite thresholds for performing track rewrite processing in a first sector group and a second sector group, and rewriting the first sector group and the second sector group at different frequencies, the first sector group including at least one first sector continuous in the circumferential direction of the disk and capable of performing track-based error correction processing based on a first parity sector and the first parity sector, and the second sector group including at least one second sector continuous in the circumferential direction and unable to perform track-based error correction processing.

The embodiment of the invention relates to a heat-assisted magnetic recording and reproducing apparatus and an adjusting method thereof. In the method of adjusting a heat-assisted magnetic recording and reproducing apparatus according to an embodiment, a heat-assisted magnetic recording head of the heat-assisted magnetic recording and reproducing apparatus is maintained in orbit, a recording current for data recording is maintained to be less than a threshold value for the heat-assisted magnetic recording head, and a light source driving current for emitting light is applied to a light source.

A method of forming a read head is described where a Tunneling Magnetoresistive (TMR) stack of layers comprised of a free layer (FL) and having sidewalls separated by a cross-track width is formed on a bottom shield. In subsequent steps, a first insulation layer and longitudinal biasing layer are formed on the sidewalls and bottom shield. After a TMR sensor backside is formed that exposes the bottom shield, a second insulation layer and permanent magnet (PM) layer are deposited on exposed portions of the bottom shield. Thereafter, the PM layer magnetization is initialized in a direction that adjusts FL bias point, and shifts sensor asymmetry (Asym) closer to 0% for individual heads at slider or Head Gimbal Assembly level to provide a significant improvement in device yield. Asym is adjusted using different initialization schemes and initialization directions. With individual heads, initialization direction is selected based on a prior asymmetry measurement.

To provide a magnetic head and a magnetic recording device capable of improving the characteristics.SOLUTION: A magnetic head 110 includes a first magnetic pole 31, a second magnetic pole 32, a conductive portion 30c, an element portion 20, a first terminal T1, a second terminal T2, a third terminal T3, and a fourth terminal T4. The conductive portion 30c is electrically insulated from the first magnetic pole 31 and the second magnetic pole 32. The first terminal T1 and the second terminal T2 are electrically connected to the conductive portion 30c. The element portion 20 is provided between the first magnetic pole 31 and the second magnetic pole 32, is electrically connected to the first magnetic pole 31 and the second magnetic pole 32, and has conductivity. The third terminal T3 is electrically connected to the first magnetic pole 31. The fourth terminal T4 is electrically connected to the second magnetic pole 32. The first magnetic pole temperature of the first magnetic pole 31 in a first state where a first current i1 is supplied between the first terminal T1 and the second terminal T2 is higher than the second magnetic pole temperature of the second magnetic pole 32 in the first state.SELECTED DRAWING: Figure 1

According to one embodiment, a magnetic recording device includes a magnetic recording medium, a plurality of magnetic heads for recording information on the magnetic recording medium, and a controller for controlling the magnetic heads. Each of the magnetic heads includes a coil, a first magnetic pole for generating a magnetic field according to a recording current supplied to the coil, and a light emitting section for irradiating the magnetic recording medium with light to locally increase a temperature of the magnetic recording medium. The controller performs a first operation, in which a lifetime information related to a remaining life time of one of the magnetic heads is calculated based on a first information related to a failure probability of a magnetic head group including the magnetic heads and a second information related to a remaining time based on a history of the one of the magnetic heads.

A data storage device comprises a magnetic medium and a head configured to be actuated over the magnetic medium. The head comprises a write element and a write driver configured to generate a write current to be applied to the write element. The write driver comprises a data switch section configured to switchably output low-level signals and high-level signals, and a stationary cascode section configured to receive the low-level signals and high-level signals from the data switch section and to generate a cascode pass through current. The data switch section comprises low voltage CMOS devices and the stationary cascode section comprises high voltage CMOS devices.