Abstract: When a master medium and a slave medium are brought into close contact and a transfer magnetic field is applied thereto to perform magnetic transfer, the leakage magnetic field intensity of the transfer magnetic field is regulated to within a permissible range, making possible the transfer of an exact magnetic pattern. After a magnetic field is applied to the slave face in the track direction thereof to initially magnetize the slave medium in the track direction, the master medium and the slave medium are brought into close contact. When applying a transfer magnetic field in the track direction of the slave face to perform a magnetic transfer, the magnetic field intensity component in the direction opposite that in which the transfer magnetic field is to be applied is regulated to less than or equal to ½ the magnetic coercive force Hcs of the slave medium over the entire slave surface.

Abstract: To ensure smooth rotation of a rotary shutter.

Abstract: A disk cartridge having an improved dust removing capability for removing dirt or dust on a surface of an information recording medium is provided.

Abstract: A flexible magnetic recording medium includes a non-magnetic layer and a magnetic layer consisting of ferromagnetic powder dispersed in binder which are formed on a base sheet in this order. The ferromagnetic powder is not smaller than 158 kA/m in coercive force Hc(VSM) as measured by a vibrating sample magnetometer and is not larger than 100 in KuV/kT (wherein Ku represents an anisotropy constant, V represents a volume, k represents a Boltzmann constant and T represents an absolute temperature) which is a parameter of thermal fluctuation, and a magnetization pattern representing predetermined information has been formed on the magnetic layer by magnetic transfer.

Abstract: A magnetic disc medium comprising: a support; a substantially nonmagnetic lower layer; and a magnetic layer comprising a binder and hexagonal ferrite powder dispersed in the binder, in this order, wherein the magnetic disc medium has an outside diameter of from 20 to 50 mm, an amount of run out in a vertical direction at an outside perimeter of the disc medium in recording and reproducing of 50 &mgr;m or less, and an amount of run out in a vertical direction at an inside perimeter of the disc medium in recording and reproducing of 25 &mgr;m or less, and a recording and reproducing method of the magnetic disc medium, wherein the magnetic disc medium has an outside diameter of from 20 to 50 mm, and recording and reproducing are performed at an engine speed to make an amount of run out in a vertical direction at an outside perimeter of the disc medium 50 &mgr;m or less, and an amount of run out in a vertical direction at an inside perimeter 25 &mgr;m or less.

Abstract: In order to increase a recording capacity of a magnetic disk cartridge without enlarging an area of a flat surface, two magnetic disk media 14 and 15 are contained in a housing which includes half shells 11 and 12 in the magnetic disk cartridge 10 by fixedly attaching the magnetic disc media 14 and 15 to a center core 13 so as to be held thereby.

Abstract: A flexible magnetic recording medium includes a non-magnetic layer and a magnetic layer consisting of ferromagnetic powder dispersed in binder which are formed on a base sheet in this order. The ferromagnetic powder is not smaller than 158 kA/m in coercive force Hc (VSM) as measured by a vibrating sample magnetometer and is not larger than 100 in KuV/kT (wherein Ku represents an anisotropy constant, V represents a volume, k represents a Boltzmann constant and T represents an absolute temperature) which is a parameter of thermal fluctuation, and a magnetization pattern representing predetermined information has been formed on the magnetic layer by magnetic transfer.

Abstract: When a master medium and a slave medium are brought into close contact and a transfer magnetic field is applied thereto to perform magnetic transfer, the leakage magnetic field intensity of the transfer magnetic field is regulated to within a permissible range, making possible the transfer of an exact magnetic pattern. After a magnetic field is applied to the slave face in the track direction thereof to initially magnetize the slave medium in the track direction, the master medium and the slave medium are brought into close contact. When applying a transfer magnetic field in the track direction of the slave face to perform a magnetic transfer, the magnetic field intensity component in the direction opposite that in which the transfer magnetic field is to be applied is regulated to less than or equal to ½ the magnetic coercive force Hcs of the slave medium over the entire slave surface.

Abstract: A process for producing a magnetic disk having a randomly oriented magnetic powder, comprises: applying a magnetic coating solution containing at least a magnetic powder to a web that is being continuously conveyed, so as to prepare a magnetic layer; applying a first external magnetic field to the magnetic layer while the magnetic layer is wet; and applying a second external magnetic field to the magnetic layer while the magnetic layer is wet, wherein: the first external magnetic field is applied with a set of a first pair of same-pole-opposed magnets with the web interposed therebetween and a second pair of same-pole-opposed magnets with the web interposed therebetween; the first and second pairs are provided on the same plane of the web and on two equal sides of an isosceles triangle so that a perpendicular line dropped from a base of the isosceles triangle forms a line perpendicular to a conveying direction of the web; and the second external magnetic field is an alternating magnetic field, and is applied

Abstract: A magnetic recording medium is described, which comprises a support having thereon a substantially nonmagnetic lower layer and a magnetic layer comprising a ferromagnetic metal powder or a ferromagnetic hexagonal ferrite powder dispersed in a binder provided on the lower layer, which is a magnetic recording medium for recording signals of from 0.17 to 2 G bit/inch2 of areal recording density, wherein the dry thickness of the magnetic layer is from 0.05 to 0.30 &mgr;m , &phgr;m is from 10.0×10−3 to 1.0×10−3 emu/cm2, the coercive force of the magnetic layer is 1,800 Oe or more, and a filler having an average particle size of from 0.05 to 0.3 &mgr;m is present on the surface layer of the support in an amount of from 5,000,000 to 30,000,000/mm2.

Abstract: A process for producing a magnetic disk having a randomly oriented magnetic powder, comprises: applying a magnetic coating solution containing at least a magnetic powder to a web that is being continuously conveyed, so as to prepare a magnetic layer; applying a first external magnetic field to the magnetic layer while the magnetic layer is wet; and applying a second external magnetic field to the magnetic layer while the magnetic layer is wet, wherein: the first external magnetic field is applied with a set of a first pair of same-pole-opposed magnets with the web interposed therebetween and a second pair of same-pole-opposed magnets with the web interposed therebetween; the first and second pairs are provided on the same plane of the web and on two equal sides of an isosceles triangle so that a perpendicular line dropped from a base of the isosceles triangle forms a line perpendicular to a conveying direction of the web; and the second external magnetic field is an alternating magnetic field, and is applied

Abstract: A magnetic recording medium which comprises a support having thereon a substantially nonmagnetic lower layer and a magnetic layer comprising a ferromagnetic metal powder or a ferromagnetic hexagonal ferrite powder dispersed in a binder provided on the lower layer, which is a magnetic recording medium for recording signals of from 0.17 to 2 G bit/inch2 of areal recording density, wherein the coercive force of the magnetic layer is 1,800 Oe or more, and the thickness unevenness of the support is 5% or less of the thickness of the support.

Abstract: A magnetic recording medium is disclosed, which comprises a support having thereon a substantially nonmagnetic lower layer and a magnetic layer comprising a ferromagnetic metal powder or a ferromagnetic hexagonal ferrite powder dispersed in a binder formed on the lower layer, which is a magnetic recording medium for recording signals having areal recording density of from 0.17 to 2 G bit/inch2, wherein the coercive force of the magnetic layer is 1,800 Oe or more, the average long axis length of the ferromagnetic metal powder is 0.15 &mgr;m or less, and the average particle size of the ferromagnetic hexagonal ferrite powder is 0.10 &mgr;m or less; or wherein the dry thickness of the magnetic layer is from 0.05 to 0.30 &mgr;m, &phgr;m is from 10.0×10−3 to 1.0×10−3 emu/cm2, and the coercive force of the magnetic layer is 1,800 Oe or more.