Abstract: In the magnetic transferring method for magnetically transferring an information signal such as a servo signal from the master medium to the slave medium, when magnetic transfer is performed by bringing a master medium and a slave medium into close contact with each other, the master medium bearing an information signal and the slave medium having a lubricating layer formed on the surface of its recording plane during use, and applying a transfer magnetic field, the magnetic transfer is performed by bringing the slave medium before the formation of the lubricating layer and the master medium into close contact with each other. Thus, the separation of the slave medium from the master medium after the magnetic transfer is facilitated, and the adsorption of dust on the slave medium is prevented.

Abstract: A master information carrier for magnetic transfer to an in-plane magnetic recording medium includes a base sheet having an irregularity pattern representing information to be transferred to an in-plane magnetic recording medium and a magnetic layer formed along the irregularity pattern. The thickness da1 of the magnetic layer on the upper surface of a protruding portion of the irregularity pattern and the thickness da2 of the magnetic layer on each of the side surfaces of the protruding portion satisfy the following condition, 0.05<da2/da1?1.3.

Abstract: A process for producing a master carrier contains steps of: forming a desired pattern on a support to form a resist pattern support; forming a first ferromagnetic thin film on the resist pattern support by a vacuum film forming method; forming a third ferromagnetic thick film on the first ferromagnetic thin film by an electroplating; and peeling the support from the resist pattern support provided with the first ferromagnetic thin film and the third ferromagnetic thick film.

Abstract: In a master carrier for magnetic transfer which comprises a data region and a servo pattern region that has a pattern of fine projections arrayed in the track direction thereof in accordance with the preformat signal information to be transferred onto an in-plane magnetic recording medium, the data region have a projection formed of a material such as carbon-based material that differs from the material of the servo pattern region.

Abstract: In a master carrier for magnetic transfer which comprises a support that has a transfer-recording pattern arrayed in the track direction thereof in accordance with the information to be transferred to a magnetic recording medium, and a magnetic layer formed on the transfer-recording pattern of the support, the in-plane distance L (mm) between the hill and the valley of the warped master carrier, the vertical-direction distance H (?m) between the two, and the thickness d (mm) of the master carrier are so defined that they satisfy a relation of 0.05?H·d3/L?0.6.

Abstract: A magnetic recording medium, which comprises a flattening layer with a thickness of 0.1-5.0 &mgr;m, a seed layer, a nonmagnetic primer layer containing chromium with a chromium concentration of 77-100 atom %, a Co—Cr type alloy magnetic layer, a protective layer, and a lubricating layer coated sequentially on at least one of the surfaces of a flexible nonmagnetic support member, whereby the seed layer is designed in such a manner that the linear expansion coefficient (ESE) of the seed layer and the linear expansion coefficient (EUL) of the nonmagnetic primer layer satisfy the relation: |ESE−EUL|/EUL<0.3, and the tensile strength (SSE) of the seed layer and the tensile strength (SUL) of the nonmagnetic primer layer satisfy the relation: SSE/SUL>1.

Abstract: There are provided an information recording medium which permits accurate tracking servo, and a method for recording and reproducing for an information recording medium which allows recording and reproducing of a signal at a favorable S/N by carrying out at least one of information recording and information reproduction while accurately performing tracking servo. A magneto-optic disk includes a magnetic recording layer for magnetically recording information. The magnetic recording layer is in advance magnetized for concentrically or spirally around the center of the disk in such a manner that magnetized regions are disposed such that adjacent regions are magnetized in different directions and alternately arranged in the radial direction of the disk. Accordingly, tracking can be continuously performed and accurate tracking servo can also be performed.

Abstract: Pattern damage caused by defects and the like of a magnetic layer provided on a substrate of a master carrier for magnetic transfer is prevented and durability of the master carrier is improved. The master carrier for magnetic transfer includes a lamination structure, on a substrate, in which not less than one of two-layer structures laminated in a lamination direction, each of the two-layer structures including a magnetic layer and a hard layer having higher hardness than the magnetic layer, which are laminated on each other in an order of the hard layer and the magnetic layer from the substrate side. The master carrier further includes a hard layer which has higher hardness than the magnetic layer on a top surface of the lamination structure.

Abstract: In a magnetic transfer master carrier, as a substrate, one having a Young's modulus E (GPa) in the range of 85 to 250 is used. Magnetic transfer is performed under conditions in which 2≦&agr;Ed3/{P(S2/S1)}≦400 (where the constant &agr;=7.37×109) is satisfied, where d (m) is the thickness of the substrate from the bottom face of a recessed portion to the back face, S1 (m2) is the total area of the cross sections of the projected portions which are parallel to the plane of the substrate at a height of 50% of Dmax from the bottom face of the recessed portion when the height from the bottom face of the recessed portion to the top face of a projected portion is denoted by Dmax, S2 (m2) is the total area of the bottom faces of the recessed portions and the cross sections of the projected portions at the positions of the relevant bottom faces, and P (MPa) is the tight contact pressure between the master carrier and the slave medium at the time of magnetic transfer.

Abstract: The invention provides a method for performing magnetic transfer by bringing a master carrier for magnetic transfer and a slave medium in close contact with each other and by applying a magnetic field for transfer, whereby a product (Ms1&dgr;1) of saturation magnetization (Ms1) and film thickness (&dgr;1) of a magnetic layer of the master carrier to be used for magnetic transfer on a surface of the slave medium with earlier magnetic transfer and a product (Ms2&dgr;2) of saturation magnetization (Ms2) and film thickness (&dgr;2) of a magnetic layer of the master carrier are in a relation of: 1.5<(MS2&dgr;2)/(Ms1&dgr;1)<10, and a transfer magnetic field (Hdu1) applied to the surface with the earlier magnetic transfer and a transfer magnetic field (Hdu2) on the surface of the slave medium with the subsequent magnetic transfer are in a relation of: 0.2≦Hdu2/Hdu1≦0.9.

Abstract: A master information carrier for magnetic transfer to an in-plane magnetic recording medium includes a base sheet having an irregularity pattern representing information to be transferred to an in-plane magnetic recording medium and a magnetic layer formed along the irregularity pattern. The thickness da1 of the magnetic layer on the upper surface of a protruding portion of the irregularity pattern and the thickness da2 of the magnetic layer on each of the side surfaces of the protruding portion satisfy the following condition, 0.05<da2/da1≦1.3.

Abstract: A favorable magnetic transfer is performed to a perpendicular magnetic recording medium. A master medium is provided with a substrate on the surface of which protrusion portions, which form a pattern corresponding to the data that is to be transferred, having a pliable layer thereon have been formed. The master medium is further provided with a soft magnetic layer formed in the depression portions between the protrusion portions, and which is magnetically linked to the soft magnetic layer of the protrusion portions. The soft magnetic layer of the surface of the protrusion portions is conjoined with the magnetic recording layer of a perpendicular magnetic recording medium to form a conjoined body, and a transfer magnetic field is applied to the conjoined body in the direction from the substrate of the master medium toward the slave medium to perform the magnetic transfer.

Abstract: A favorable magnetic transfer is performed to a perpendicular magnetic recording medium. A master medium is provided with a substrate on the surface of which protrusion portions, which form a pattern corresponding to the data that is to be transferred, having a pliable layer thereon have been formed. The master medium is further provided with a soft magnetic layer formed in the depression portions between the protrusion portions, and which is magnetically linked to the soft magnetic layer of the protrusion portions. The soft magnetic layer of the surface of the protrusion portions is conjoined with the magnetic recording layer of a perpendicular magnetic recording medium to form a conjoined body, and a transfer magnetic field is applied to the conjoined body in the direction from the substrate of the master medium toward the slave medium to perform the magnetic transfer.

Abstract: The foreign matter adhered to the data bearing surface of a master medium is removed by use of a dry, non-contact removal process, so as to facilitate the performance of a high transfer quality magnetic transfer. Before performing a magnetic transfer or forming an optical disk, a magnetic transfer master medium or an optical disk master medium is placed in a vacuum chamber. The vacuum chamber is evacuated by an evacuating means, and a reactive gas is introduced thereto by a gas introducing means. In the state in which the chamber has been evacuated and the reactive gas has been introduced thereto, a discharging means applies a discharge voltage in the chamber, causing a plasma discharge to be generated between the master medium and an electrode. The plasma etching action of the plasma discharge burns off the foreign matter adhered to the surface of the master medium.

Abstract: The present invention provides a magnetic transfer method for transferring information by bringing a master carrier for magnetic transfer and a slave medium into close contact with each other and by applying a magnetic field for magnetic transfer, said master carrier of magnetic transfer comprising servo areas to be transferred from the master carrier to the slave medium and data areas not to be transferred, both on the same plane.

Abstract: A master information carrier for magnetic transfer includes a master substrate made of metal, including an embossed pattern corresponding to information to be transferred. The master substrate is produced by laminating a metal disk with a predetermined thickness on an original disk, on which an embossed pattern is formed, by electroforming, peeling off the metal disk and die-cutting a disk in a desired size. An outer diameter of the metal disk is at least 1.7 times longer than an outer diameter of the die-cut master substrate. When the metal disk is peeled off from the original disk, deformation due to the forces acting from the side of the outer circumference is reduced. The flatness of the metal disk is ensured and the transfer qualities are improved. Further, a step of removing distortion of the metal disk, caused at the time of peeling off the metal disk, may also be provided.

Abstract: A favorable magnetic transfer is performed to a perpendicular magnetic recording medium. A master medium is provided with a substrate on the surface of which protrusion portions, which form a pattern corresponding to the data that is to be transferred, having a pliable layer thereon have been formed. The master medium is further provided with a soft magnetic layer formed in the depression portions between the protrusion portions, and which is magnetically linked to the soft magnetic layer of the protrusion portions. The soft magnetic layer of the surface of the protrusion portions is conjoined with the magnetic recording layer of a perpendicular magnetic recording medium to form a conjoined body, and a transfer magnetic field is applied to the conjoined body in the direction from the substrate of the master medium toward the slave medium to perform the magnetic transfer.

Abstract: The present invention provides a magnetic transfer method for transferring information by bringing a master carrier for magnetic transfer and a slave medium into close contact with each other and by applying a magnetic field for transfer, said master carrier comprising servo areas and data areas, said servo areas are convex, and difference of height between the data areas and the servo areas is within the range of 50-800 nm.

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 master information carrier has on its surface a signal area where an embossed pattern formed by protruding portions and recessed portions and representing a signal pattern to be transferred has been formed. The shortest bit length of the embossed pattern is 300 nm or shorter, and the embossed pattern is formed so that the total of the areas of the upper surfaces of the protruding portions of the embossed pattern is smaller than the total of the areas of inter-protruding-portions in the signal area.