Abstract: In a recording/reproducing method of a magnetic tape in a tracking servo system, a recording density of each data track is increased while inhibiting occurrence of a recording/reproducing error caused by a size change of a magnetic tape in the width direction. Data tracks are each set to have a smaller track width stepwise as closer to servo tracks (41T-1 to 41T-5 etc.) in the width direction of a magnetic tape 1. With such a setting, the width of the data tracks (A1-41T-1 to A1-41T-5 etc. ) closest to the servo tracks (41T-1 to 41T-5) can be minimized, thereby enabling a significant increase in number of the data tracks.

Abstract: An optical film according to the present invention comprises a transparent base, and an anti-reflection layer that is disposed on one main face of the transparent base. The anti-reflection layer includes a hard coating layer, and a low refractive index layer that is disposed on the hard coating layer in this order from the side of the transparent base. The hard coating layer is formed using a resin containing an ionizing radiation setting resin. The hard coating layer contains a conductive metal oxide in an amount of at least 5 wt % and at most 30 wt % with respect to the total weight of the hard coating layer. The hard coating layer is formed using a coating solution containing water in an amount of at least 0.05 wt % and at most 5.0 wt %.

Abstract: In a recording/reproducing method of a magnetic tape in a tracking servo system, a recording density of each data track is increased while inhibiting occurrence of a recording/reproducing error caused by a size change of a magnetic tape in the width direction. Data tracks are each set to have a smaller track width stepwise as closer to servo tracks (41T-1 to 41T-5 etc.) in the width direction of a magnetic tape 1. With such a setting, the width of the data tracks (A1-41T-1 to A1-41T-5 etc.) closest to the servo tracks (41T-1 to 41T-5) can be minimized, thereby enabling a significant increase in number of the data tracks.

Abstract: A magnetic tape cartridge comprises: a magnetic tape on which data tracks and servo tracks are provided; a casing housing the magnetic tape therein: and a storing section which stores values of tape width detected during data recording onto the data tracks of the magnetic tape and from which the stored values of tape width are read out during data reproduction from the data tracks of the magnetic tape.

Abstract: In a recording/reproducing method of a magnetic tape in a tracking servo system, a recording density of each data track is increased while inhibiting occurrence of a recording/reproducing error caused by a size change of a magnetic tape in the width direction. Data tracks are each set to have a smaller track width stepwise as closer to servo tracks (41T-1 to 41T-5 etc.) in the width direction of a magnetic tape 1. With such a setting, the width of the data tracks (A1-41T-1 to A1-41T-5 etc.) closest to the servo tracks (41T-1 to 41T-5) can be minimized, thereby enabling a significant increase in number of the data tracks.

Abstract: The present invention provides an optical film including: a base; a first functional layer provided on one principal plane of the base via a first adhesion-improving layer; and a second functional layer that is different from the first functional layer and is provided on the other principal plane of the base via a second adhesion-improving layer. The first adhesion-improving layer contains a resin that is different from a resin contained in the second adhesion-improving layer, and the second functional layer contains a resin of the same type as the resin contained in the second adhesion-improving layer. The optical film according to the present invention achieves excellent adhesion between the respective functional layers and the base as well as excellent reflectance spectral characteristics.

Abstract: A recording/reproducing method and a recording/reproducing apparatus for magnetic tapes are provided as a recording/reproducing technique suitable for recording density enhancement of magnetic tapes. The method and apparatus are capable of correctly recording and reproducing data without causing errors even with occurrence of size changes in the widthwise direction of a magnetic tape. In the recording/reproducing method for magnetic tapes in which data tracks and servo tracks are provided, a tape width is detected and a value of the tape width is stored during data recording, and data reproduction is performed while tape tension is controlled so that the tape width during data reproduction is maintained equal to the tape width during data recording.

Abstract: In a single-reel type tape cartridge of a servo tracking system in which signal recording is performed, a tape reel capable of eliminating edge projection during tape winding and achieving high recording density of a magnetic tape is provided. The tape reel is provided with a cylindrical hub around which the magnetic tape is wound and a pair of upper and lower flanges. The average value of the thickness of a reference flange that receives the tape edge of the magnetic tape during tape winding is set greater than the average value of the thickness of the opposite flange. The tape receiving surface of the reference flange is formed into an inclined surface, and three or more air escape recess portions are formed on the tape receiving surface. The depth of each air escape recess portion is set not smaller than 0.05 mm and not greater than 0.40 mm. The occupation area of all the air escape recess portions is set to 30% to 80% of the total area of the reference flange.

Abstract: A recording/reproducing method and a recording/reproducing apparatus for magnetic tapes are provided as a recording/reproducing technique suitable for recording density enhancement of magnetic tapes. The method and apparatus are capable of correctly recording and reproducing data without causing errors even with occurrence of size changes in the widthwise direction of a magnetic tape. In the recording/reproducing method for magnetic tapes in which data tracks and servo tracks are provided, a tape width is detected and a value of the tape width is stored during data recording, and data reproduction is performed while tape tension is controlled so that the tape width during data reproduction is maintained equal to the tape width during data recording.

Abstract: A magnetic tape comprising a non-magnetic substrate and at least one magnetic layer formed on one surface of the non-magnetic substrate, characterized in that magnetic particles contained in an uppermost magnetic layer of the magnetic layer are substantially granular particles with a particle size of 30 nm or less, and that the ratio of a coercive force HcM in the machine direction to a coercive force HcT in the transverse direction, i.e., [HcM/HcT], is at least 2.2. This magnetic tape has a capacity capable of corresponding to mass storage of 1 TB or more, and achieves a high ratio of reproducing output to noises (C/N), particularly for signals within a short wavelength range, thus showing excellent high-density recording performance.

Abstract: A magnetic recording medium with excellent high density recording performances and good durability comprising a non-magnetic substrate, a non-magnetic layer containing a non-magnetic powder and a binder formed on the non-magnetic substrate, and a magnetic layer having a thickness of less than 100 nm and containing a substantially particulate non-magnetic powder, a substantially particulate magnetic powder having an average particle size of less than 25 nm, and a binder, wherein an average particle size R of the non-magnetic powder contained in the magnetic layer and a thickness D of the magnetic powder satisfy the following relationship: 0.88?R/D?2.5.

Abstract: In a single-reel type tape cartridge of a servo tracking system in which signal recording is performed, a tape reel capable of eliminating edge projection during tape winding and achieving high recording density of a magnetic tape and a magnetic tape cartridge for housing the tape reel is provided. The tape reel is provided with a cylindrical hub around which the magnetic tape is wound and a pair of upper and lower flanges. The average value of the thickness of a reference flange that receives the tape edge of the magnetic tape during tape winding is set greater than the average value of the thickness of the opposite flange. The tape receiving surface of the reference flange is formed into an inclined surface, and three or more air escape recess portions are formed on the tape receiving surface. The depth of each air escape recess portion is set not smaller than 0.05 mm and not greater than 0.40 mm.

Abstract: A magnetic tape comprising a non-magnetic support, a magnetic layer containing magnetic powder which is formed on one side of the non-magnetic support, a primer layer containing non-magnetic powder which is formed between the non-magnetic support and the magnetic layer, and a backcoat layer containing non-magnetic powder which is formed on the other side of the non-magnetic support, wherein the magnetic layer contains the magnetic powder which comprises plate, granular or ellipsoidal magnetic particles with a particle diameter of 5 to 50 nm, and has a thickness of 0.09 ?m or less, and wherein at least one of the primer layer and the backcoat layer contains non-magnetic plate particles with a particle diameter of 10 to 100 nm.

Abstract: A magnetic recording medium comprising a non-magnetic support, at least one primer layer formed on one surface of the non-magnetic support, comprising a non-magnetic powder and a binder resin, at least one magnetic layer formed on the primer layer, comprising a magnetic powder and a binder resin, and a back layer formed on the other surface of the non-magnetic support, wherein the magnetic powder contained in the uppermost layer of the magnetic layer is a rare earth metal-iron type magnetic powder of substantially spherical or ellipsoidal particles comprising a rare earth element and iron or a transition metal which comprises iron, and has a number average particle size 5 to 50 nm and an average axis ratio of 1 to 2, and the total thickness of the magnetic recording medium is less than 6 ?m. This magnetic recording medium can achieve an excellent block error rate, which cannot be realized with magnetic recording media comprising conventional acicular magnetic powders.

Abstract: A magnetic tape comprising a non-magnetic support, a primer layer formed on one surface of the support, a magnetic layer formed on the primer layer, and a back layer formed on the other surface of the support, in which the tape has a total thickness of 4.0 to 5.4 ?m, at least one of the primer layer and the magnetic layer contains a fatty acid amide, and an amount of the fatty acid amide extracted from the side of the magnetic layer with n-hexane is from 0.5 to 1.5 mg/cm3.

Abstract: In a recording/reproducing method of a magnetic tape in a tracking servo system, a recording density of each data track is increased while inhibiting occurrence of a recording/reproducing error caused by a size change of a magnetic tape in the width direction. Data tracks are each set to have a smaller track width stepwise as closer to servo tracks (41T-1 to 41T-5 etc.) in the width direction of a magnetic tape 1. With such a setting, the width of the data tracks (A1-41T-1 to A1-41T-5 etc.) closest to the servo tracks (41T-1 to 41T-5) can be minimized, thereby enabling a significant increase in number of the data tracks.

Abstract: A magnetic tape having excellent high recording density characteristics, good durability and good servo-tracking characteristics, which comprises a non-magnetic support, a magnetic layer formed on one surface of the non-magnetic support and containing a magnetic powder, a primer layer provided between the non-magnetic support and the magnetic layer and containing a non-magnetic powder, and a back coat layer formed on the other surface of the non-magnetic support, wherein the non-magnetic powder is goethite particles having an average particle size in a range of from 5 nm to 100 nm and the magnetic tape has an edge weave amount of 1.0 ?m or less.

Abstract: There is provided a magnetic recording medium comprising a flexible non-magnetic substrate, and a magnetic layer containing magnetic particles, formed on at least one surface of the flexible non-magnetic substrate, and this magnetic recording medium is characterized in that an uppermost layer formed on the side of the magnetic layer is a non-magnetic layer with a thickness of 1 to 50 nm, which contains a resin and has a surface roughness (P-V) of 2 to 20 nm. This magnetic recording medium is excellent in high density recording performance, and is highly reliable in durability.

Abstract: A magnetic tape comprising a non-magnetic support, a magnetic layer containing magnetic powder which is formed on one side of the non-magnetic support, a primer layer containing non-magnetic powder which is formed between the non-magnetic support and the magnetic layer, and a backcoat layer containing non-magnetic powder which is formed on the other side of the non-magnetic support, wherein the magnetic layer contains the magnetic powder which comprises plate, granular or ellipsoidal magnetic particles with a particle diameter of 5 to 50 nm, and has a thickness of 0.09 &mgr;m or less, and wherein at least one of the primer layer and the backcoat layer contains non-magnetic plate particles with a particle diameter of 10 to 100 nm.

Abstract: A magnetic recording medium comprising a non-magnetic support; at least one lower magnetic layer containing magnetic powder and a binder resin, which is formed on one side of the non-magnetic support with or without a non-magnetic primer layer interposed between the non-magnetic support and the lower magnetic layer; at least one non-magnetic intermediate layer containing non-magnetic powder and a binder resin, which is formed on the lower magnetic layer; at least one upper magnetic layer containing magnetic powder and a binder resin, which is formed on the non-magnetic intermediate layer; and a back layer which is formed on the other side of the non-magnetic support, characterized in that the magnetic powder contained in the uppermost magnetic layer of the upper magnetic layer is iron type magnetic powder which comprises substantially spherical or ellipsoidal particles with a number-average particle diameter of 5 to 50 nm and an average axial ratio of 1 to 2, each of said particles containing iron or containi