| Patent application number | Description | Published |
|---|
| 20090251816 | Patterned medium inspection method and inspection device - A defect inspection method and device for a perpendicular magnetic recording medium that has discrete recording tracks and grooves between recording tracks, including DC demagnetizing the perpendicular magnetic recording medium, detecting a reproduced signal from the perpendicular magnetic recording medium after the DC demagnetizing, removing output fluctuation components caused by the grooves from the reproduced signal using a filter with a prescribed cutoff frequency and separating a peak output of the reproduced signal, comparing the peak output with a prescribed reference signal, and identifying a location where the peak output exceeds the reference signal as a defect location. The method further includes performing an envelope-detection on the reproduced signal, detecting a pre-format region in the perpendicular magnetic recording medium using the envelope-detection result, masking the detected pre-format region, and detecting the defect location in a region outside the masked pre-format region in the perpendicular magnetic recording medium. | 10-08-2009 |
| 20110013303 | MAGNETIC TRANSFER DEVICE AND MAGNETIC TRANSFER METHOD - A magnetic transfer device and method are provided. A magnetic field generating structure comprises a pair of permanent magnets connected to a return yoke. Respective magnetic poles of the magnets, of a different polarity from one another, oppose each other with a conjoined body disposed therebetween. The magnetic field generating structure is moved from a position at an outer periphery of the conjoined body, to a position at an inner periphery of the conjoined body, and then moved from the position at the inner periphery across the conjoined body toward the outer periphery, to a position outside of the conjoined body. The return yoke is positioned at a radially more outward position, toward the outer periphery, than are the permanent magnets. The movement of the magnetic field generating structure is carried out while maintaining a constant distance from the rotating conjoined body. | 01-20-2011 |
| 20110096429 | MASTER DISK FOR MAGNETIC TRANSFER, A METHOD OF DRAWING A MAGNETIC TRANSFER PATTERN, AND A MAGNETIC RECORDING MEDIUM HAVING A TRANSFERRED MAGNETIC TRANSFER PATTERN - A master disk for magnetic transfer of a reference servo signal in a spiral mode, having a pattern including a plurality of dots groups, which are disposed at different radial positions of the master disk with a first pitch, and correspond to the reference servo signal in the spiral mode. Each of the plurality of dot groups includes a plurality of dots, successively disposed with a second pitch along a circumferential direction of the master disk at a same one of the radial positions. Each of the plurality of dots is of a ferromagnetic material, and has four sides, two opposing sides thereof extending in the circumferential direction, and the other two opposing sides thereof extending in a radial direction of the master disk. | 04-28-2011 |
| 20110096640 | METHOD OF DRAWING A PATTERN FOR MAGNETIC TRANSFER - A method of drawing a pattern for magnetic transfer on a substrate, including the steps of rotating the substrate and scanning the substrate, by an electron beam, in a circumferential direction thereof, deflecting, using a deflection signal, the electron beam in a radial direction thereof, and switching irradiation of the electron beam on and off, so as to create the pattern of a plurality of dots. | 04-28-2011 |
| 20110181975 | METHOD OF MANUFACTURING A MASTER DISK FOR MAGNETIC TRANSFER - A method of manufacturing a master disk for magnetic transfer is provided in which a pattern configuration does not change and burrs that require a polishing process are not generated. The method of manufacturing a master disk for magnetic transfer can include preparing a nonmagnetic body, forming a pattern of recessed parts on the nonmagnetic body, and forming a ferromagnetic material layer by depositing a ferromagnetic material on a surface of the nonmagnetic body having the pattern of recessed parts thereon. The method can further include forming a pattern of ferromagnetic material layers at the recessed parts by removing an excess portion of the ferromagnetic layer without using a mask. An etching rate of the nonmagnetic body can be larger than an etching rate of the ferromagnetic material layer in the operation of forming a pattern of ferromagnetic material layers at the recessed parts. | 07-28-2011 |
