33results about "Magnetic field orientation" patented technology

To provide a magnetic tape which can contribute to increase of the operation stability of a drive in recording and / or reproduction after a long-time storage.SOLUTION: The magnetic tape has a non-magnetic supporting body and a magnetic layer including ferromagnetic powders. The present invention also provides a magnetic tape cartridge and a magnetic tape device including the magnetic tape. The height Spk of a protruding mounting part defined by ISO 25178 in the surface of the magnetic layer is at least 1.5nm and is 3.0nm at largest. The standard deviation σ of the Spk in the width direction of the surface of the magnetic layer is 0.5 nm at largest.SELECTED DRAWING: None

Provided is a magnetic tape having a non-magnetic support and a magnetic layer containing a ferromagnetic powder, wherein the protrusion height Spk defined in ISO 25178 is 1.2 to 2.8 nm inclusive, said protrusion height Spk being measured in a measurement region of 5 × 5 μm on the surface of the magnetic layer after 500 cycles of back and forth sliding with respect to an LTO8 head at a head inclination angle of 15° at a temperature of 15°C and a relative humidity of 80%.

According to one embodiment, multiple first positions are set in a radial direction of a magnetic disk. The multiple first positions include multiple second positions and a third position different from the multiple second positions. A controller of a magnetic disk apparatus executes a first process in which an RRO correction value is measured at each of the multiple second positions and measurement of an RRO correction value at the third position is skipped. After the first process, the controller executes a second process of performing write or read access to multiple tracks. The second process includes acquiring a position error signal by a read head during the write or read access, and calculating an RRO correction value for the third position based on the position error signal.

To provide a magnetic disk device that can measure PPO correction values with high efficiency.SOLUTION: A plurality of first positions are set in a radial direction of a magnetic disk. The plurality of first positions includes a plurality of second positions and a third position different from the plurality of second positions. A controller of the magnetic disk device measures a RRO (Repeatable RunOut) correction value for each of the plurality of second positions, and executes a first step in which a RRO correction value is not measured for the third position. After the first step, the controller executes a second step in which write or read access is performed on a plurality of tracks. The second step includes acquiring a position error signal by a read head during access and calculating the RRO correction value for the third position based on the position error signal.SELECTED DRAWING: Figure 5

Provided is a magnetic tape having a data tape, a leader tape, and a splice tape, wherein the thickness difference (Ttotal-Tdata) between the total thickness Ttotal of the leader tape and the splice tape and the thickness Tdata of the data tape is 30.0 μm or less, the arithmetic mean peak curvature Spc, as defined in ISO 25178, of a surface of a magnetic layer of the data tape is 0.30 (1 / μm) to 0.70 (1 / μm) inclusive, and the standard deviation σ of Spc in the width direction of the surface of the magnetic layer is 0.15 (1 / μm) or less.

A magnetic recording medium manufacturing method for manufacturing a magnetic recording medium having a substrate, an underlayer, and a perpendicular magnetic layer having a L10 structure in this order, includes heating a surface of the perpendicular magnetic layer by LED light emitted from a LED light source after forming the perpendicular magnetic layer, to improve a crystal orientation of the perpendicular magnetic layer, wherein the underlayer includes a NaCl type compound, and the LED light has a center wavelength of less than 500 nm.

To provide a servo writer that reduces the number of cartridges to be discarded.SOLUTION: A servo writer 210 for a cartridge 10 includes: a traveling portion that feeds out a tape-shaped magnetic recording medium (magnetic tape MT) from the cartridge and winds the feed magnetic recording medium to make the magnetic recording medium travel; a demagnetizing magnet 214 that erases a first servo pattern formed on the traveling magnetic recording medium; a servo signal writing head 215 that writes a servo signal onto the traveling magnetic recording medium after the first servo pattern is erased and forms a second servo pattern; and a control device that controls the head to write the servo signal during at least one of acceleration and deceleration traveling periods of the magnetic recording medium and forms the second servo pattern that does not satisfy the standard on the magnetic recording medium.SELECTED DRAWING: Figure 8

To enable recording to and / or reproduction from a magnetic tape after being stored in a storage environment where a magnetic tape cartridge accommodating the magnetic tape is exposed to temperature and humidity changes to be suitably carried out when recording and / or reproducing data to and from the magnetic tape.SOLUTION: Provided are a magnetic tape cartridge group that includes a plurality of magnetic tape cartridges and a magnetic recording-reproduction device that includes a magnetic tape cartridge. Assuming, with regard to a 100-reel magnetic tape cartridge, that A represents the maximum value of absolute value of the difference between a servo band interval obtained before being stored as prescribed and a servo band interval obtained after being stored as prescribed, the arithmetic average of media life calculated by a primary function derived from the value of A obtained for different N and the logarithmic value of a total storage time T in cycle count N storage is three years or longer, and 3σ is one year or shorter. The media life is T when A satisfies an expression 1: A=1.5-B, and B is calculated by multiplying 1 / 2 to the difference between the maximum and minimum values among the servo band intervals respectively obtained under five environments.SELECTED DRAWING: None

To provide a magnetic recording medium capable of exerting a favorable travelling performance when in use.SOLUTION: This magnetic recording medium is a tape-shaped magnetic recording medium, and comprises a substrate, an underlayer provided on the substrate, and a magnetic layer provided on the underlayer. The substrate includes polyester as a main component. The average thickness of the underlayer is 0.9 μm or less. The underlayer and the magnetic layer include lubricants. The magnetic layer has a surface with multiple pore portions and an arithmetic average roughness Ra of the surface is 2.5 nm or less. BET specific surface area of the entire magnetic recording medium in a state where the lubricant is removed therefrom and dried, is 3.5 m2 / g or more. The squareness ratio in the vertical direction is 65% or more. The average thickness of the magnetic layer is 90 nm or less. The average thickness of the magnetic recording medium is 5.6 μm or less.SELECTED DRAWING: Figure 1

The present invention provides a magnetic recording medium having excellent electromagnetic conversion characteristics. 　This magnetic recording medium being tape-shaped comprises a base body, an undercoat layer, and a magnetic layer, in order. The magnetic layer contains hexagonal ferrite particles. The crystallite size calculated from a peak derived from the (1, 1, 0) plane of hexagonal ferrite, which has been obtained by measuring the magnetic layer using an oblique-incidence X-ray diffraction method, is from 11.0 to 15.0 nm.

To provide a magnetic tape which may contribute to operational stability improvement of a drive during recording and / or reproduction after prolonged storage.SOLUTION: A magnetic tape is provided, comprising a non-magnetic support body and a magnetic layer containing ferromagnetic powder and having a 1-bromonaphthalene contact angle in a range of 45.0° to 55.0°, inclusive, as measured on a surface thereof and a standard deviation σ of the angle of 1.0° or less in a width direction of the surface thereof. Also provided are a magnetic tape cartridge and a magnetic tape device that comprise the magnetic tape.SELECTED DRAWING: None

Provided is a magnetic tape that is a data tape wherein the arithmetic mean peak curvature Spc as defined in ISO 25178 of the surface of a magnetic layer is 0.30–0.70 (1 / μm), the standard deviation σ of the Spc in the width direction of the surface of the magnetic layer is no more than 0.15 (1 / μm), and a leader pin is directly attached to an end part.

Provided is a magnetic tape having a non-magnetic support and a magnetic layer containing ferromagnetic powder, wherein the peak height Spk as defined in ISO 25178 and measured in a 5 μm × 5 μm measurement region on the surface of the magnetic layer is between 1.0 nm and 2.5 nm inclusive.

To provide a magnetic tape which may contribute to operational stability improvement of a drive during recording and / or reproduction after prolonged storage.SOLUTION: A magnetic tape is provided, comprising a non-magnetic support body and a magnetic layer containing ferromagnetic powder and having a friction coefficient of 0.35 or less as measured on a base material portion of a surface thereof and a standard deviation σ of the friction coefficient of 0.05 or less in a width direction of the surface thereof. Also provided are a magnetic tape cartridge and a magnetic tape device that comprise the magnetic tape.SELECTED DRAWING: None

To provide a magnetic tape which has no leader tape and is excellent in running stability.SOLUTION: Provided are a magnetic tape including a non-magnetic support and a magnetic layer including ferromagnetic powder, and a magnetic tape cartridge and a magnetic tape device including the magnetic tape. The magnetic tape is a data tape in which a leader pin is directly attached to an end portion, wherein in an end portion region of the surface of the magnetic layer on the leader pin attachment side, a frictional force F10 ° with respect to an LTO9 head measured at a head inclination angle of 10 ° is 4 gf to 15 gf, and the end portion region on the leader pin attachment side is a region within a range from a 5 cm position to a 20 cm position with an end of the end portion on the leader pin attachment side of the data tape as a start point 0 cm position in the longitudinal direction position.SELECTED DRAWING: None

The present invention provides a magnetic recording medium having excellent electromagnetic conversion characteristics.　This magnetic recording medium is in tape form and comprises a substrate and a magnetic layer containing magnetic particles. The average thickness of the magnetic recording medium is 5.40 μm or less, the squareness ratio in the longitudinal direction of the magnetic recording medium is 0.35 or less, the average particle volume of the magnetic particles is between 0.600 × 103 nm3 and 1.50 × 103 nm3 inclusive, and the magnetic anisotropy energy Ku in the vertical direction of the magnetic recording medium is between 4.2 × 105 erg / cm3 and 8.5 × 105 erg / cm3 inclusive.

Provided is a magnetic tape that has a non-magnetic support and a ferromagnetic powder-containing magnetic layer. The reduction rate of standard deviation of a friction distribution, which is measured by a horizontal force microscope in a measurement region of 3 μm × 3 μm on a surface of the magnetic layer before and after 500-time reciprocating sliding with respect to an LTO8 head at a head inclination angle of 15° in an environment where the temperature is 15°C and the relative humidity is 80%, is 20% or more.

The present invention provides a sputtering target which enables a magnetic layer of a magnetic recording medium to maintain high coercivity, while being capable of improving magnetic separation between magnetic particles. This sputtering target contains Co and Pt as metal components, while containing NbO2 as a metal oxide component. Alternatively, this sputtering target contains Co and Pt as metal components, while having a phase that contains all of Co, Nb and O.

Provided is magnetic tape having a non-magnetic support and a magnetic layer containing ferromagnetic powder, wherein the standard deviation of the frictional force as obtained by measuring the frictional force between the surface of the magnetic layer and a guide roll of an LTO drive is 0.35-0.70 N.

The embodiment relates to a magnetic disk device. A plurality of first positions are set in the radial direction of the magnetic disk. The plurality of first positions include a plurality of second positions and a third position different from the plurality of second positions. A controller of the magnetic disk device executes a first step in which RRO (Repeatable RunOut) correction values are measured for each of a plurality of second positions, and RRO correction values are not measured for a third position. The controller executes, after the first step, a second step in which access to write or read to the plurality of tracks is performed. The second step includes: acquiring a position error signal by the head at the time of access; and calculating an RRO correction value for the third position based on the position error signal.

To provide a magnetic tape which can contribute to increase of the operation stability of a drive in recording and / or reproduction after a long-time storage.SOLUTION: The magnetic tape has a non-magnetic supporting body and a magnetic layer including ferromagnetic powders. The present invention also provides a magnetic tape cartridge and a magnetic tape device including the magnetic tape. The VIVA0.1 as the height at which the area of a cross section is 0.1% when the area of a measurement region is 100%, which is determined by performing a measurement in the surface of the magnetic layer by an atom force microscope, is at least 5nm and is 10 nm at largest. The standard deviation σ of the VIVA0.1 in the width direction of the surface of the magnetic layer is 1.0nm at largest.SELECTED DRAWING: None

Provided is a magnetic tape cartridge group including a plurality of magnetic tape cartridges. The magnetic tape contained in the magnetic tape cartridges includes a polyethylene naphthalate support having a Young's modulus of 10000 MPa or greater in the width direction. The arithmetic mean of media life calculated according to a linear function derived from the value of A determined for different values of N and the logarithm value of total storage time T for storage for N cycles is 3 years or more and 3σ is 1 year or less, where A is the maximum absolute value of the difference between a servo band interval determined before prescribed storage and a servo band interval determined after the prescribed storage for 100 magnetic tape cartridges.

A sputtering target capable of maintaining high coercive force in the magnetic layer of a magnetic recording medium and improving magnetic separation between magnetic particles is provided. A sputtering target includes Co and Pt as metal components and NbO2 as a metal oxide component. Or alternatively, a sputtering target includes Co and Pt as metal components, and includes a phase containing Co, Nb, and O.

To provide a magnetic tape which may contribute to operational stability improvement of a drive during recording and / or reproduction after prolonged storage.SOLUTION: A magnetic tape is provided, comprising a non-magnetic support body and a magnetic layer containing ferromagnetic powder and having a water contact angle in a range of 95° to 105°, inclusive, as measured on a surface thereof and a standard deviation σ of the water contact angle of 1.0° or less in a width direction of the surface thereof. Also provided are a magnetic tape cartridge and a magnetic tape device that comprise the magnetic tape.SELECTED DRAWING: None

To provide a magnetic tape which may contribute to operational stability improvement of a drive during recording and / or reproduction after prolonged storage.SOLUTION: A magnetic tape is provided, comprising a non-magnetic support body and a magnetic layer containing ferromagnetic powder, where the number of dents having circle-equivalent diameters in a range of 0.25 to 0.55 μm, inclusive, present on a surface of the magnetic layer is in a range of 10 to 500, inclusive, per area of 40×40 μm, and a standard deviation σ of the number of dents in a width direction of the surface of the magnetic layer is 50 or less. Also provided are a magnetic tape cartridge and a magnetic tape device that comprise the magnetic tape.SELECTED DRAWING: None

To enable recording to and / or reproduction from a magnetic tape after being accommodated and stored in a magnetic tape cartridge to be suitably carried out when recording and / or reproducing data to and from the magnetic tape.SOLUTION: Provided are a magnetic tape cartridge that includes a plurality of magnetic tape cartridges and a magnetic recording-reproduction device that includes a magnetic tape cartridge. Assuming, with regard to a 100-reel magnetic tape cartridge, that A represents the maximum value of absolute value of a difference between a servo band interval that is preliminarily obtained before being stored under a prescribed environment and a servo band interval that is obtained after being stored for a storage time T under the prescribed environment, the arithmetic average of media life calculated by a primary function derived from the value of A and the value of logeT that is a logarithm of T is four years or longer, and 3σ is one year or shorter. The media life is T when A satisfies an expression 1: A=1.5-B, and B is calculated by multiplying 1 / 2 to the difference between the maximum and minimum values among the servo band intervals respectively obtained under each of prescribed five environments.SELECTED DRAWING: None

To provide a magnetic tape that reduces a frequency of missing pulses in a low temperature and low humidity environment and can contribute to improving an operational stability of a drive during recording and / or reproducing after long-term storage.SOLUTION: A magnetic tape has a non-magnetic support body and a magnetic layer containing ferromagnetic powder, in which an absolute value ΔN of a difference between a refractive index Nxy measured in an in-plane direction of the magnetic layer and a refractive index Nz measured in a thickness direction of the magnetic layer is 0.25 or more and 0.40 or less, and a standard deviation σ of the ΔN in a width direction of the magnetic layer is 0.05 or less. A magnetic tape cartridge and a magnetic tape device include this magnetic tape.SELECTED DRAWING: None

Provided is a magnetic-tape cartridge group containing a plurality of magnetic tape cartridges. A magnetic tape included in the magnetic tape cartridges contains a polyethylene-naphthalate support element having a widthwise Young's modulus of 10,000 MPa or greater. For 100 reels of magnetic tape cartridges, letting the maximum absolute value of the difference between a servo band interval found prior to storage under a prescribed environment, and a servo band interval found following storage for a storage time T under the prescribed environment be A, then the arithmetic mean of media life calculated by a linear function derived from the value of A and the value of the logarithm of T, loge T, is four years or more, and the 3σ is one year or less.

According to one embodiment, multiple first positions are set in a radial direction of a magnetic disk. The multiple first positions include multiple second positions and a third position different from the multiple second positions. A controller of a magnetic disk apparatus executes a first process in which an RRO correction value is measured at each of the multiple second positions and measurement of an RRO correction value at the third position is skipped. After the first process, the controller executes a second process of performing write or read access to multiple tracks. The second process includes acquiring a position error signal by a read head during the write or read access, and calculating an RRO correction value for the third position based on the position error signal.

To provide a magnetic tape which may contribute to operational stability improvement of a drive during recording and / or reproduction after prolonged storage.SOLUTION: A magnetic tape is provided, comprising a non-magnetic support body and a magnetic layer containing ferromagnetic powder and having an AlFeSil abrasion value in a range of 20 to 50 μm, inclusive, as measured on a surface thereof and a standard deviation σ of the AlFeSil abrasion value of 5.0 μm or less as derived in a width direction of the surface thereof. Also provided are a magnetic tape cartridge and a magnetic tape device that comprise the magnetic tape.SELECTED DRAWING: None