Abstract: Disclosed is a servo writer in which a servo write head is easy to exchange, and which writes, to magnetic tapes, a servo signal from which a reading signal of the improved SN ratio can be obtained. The servo writer includes a magnetic tape running system, at least one DC erase head, a plurality of servo write heads being arranged downstream of the DC erase head, and an installation section on which the servo write heads are arranged and which includes a switching mechanism for switching the servo write heads to position one of the servo write heads at a location possible to write the servo signals on the magnetic tape.

Abstract: Disclosed is a servo writer in which a servo write head is easy to exchange, and which writes, to magnetic tapes, a servo signal from which a reading signal of the improved SN ratio can be obtained. The servo writer includes a magnetic tape running system, at least one DC erase head, a plurality of servo write heads being arranged downstream of the DC erase head, and an installation section on which the servo write heads are arranged and which includes a switching mechanism for switching the servo write heads to position one of the servo write heads at a location possible to write the servo signals on the magnetic tape.

Abstract: A magnetic disk cartridge capable of being loaded into a disk drive comprises a housing, and a magnetic disk, which is accommodated for rotation within the housing. The housing is provided with an opening, which allows a magnetic head of the disk drive to access a surface of the magnetic disk, and a shutter for opening and closing the opening. The housing has an outer peripheral shape composed of a circular arc, which is formed along a contour of the magnetic disk, and two straight lines, which are circumscribed with the circular arc formed along the contour of the magnetic disk and are normal to each other.

Abstract: The present invention provides a recording medium where data cannot be unjustly accessed even if the recording medium is stolen because a data recording area for recording data is equipped and a servo signal for controlling an access of a data recording and/or reproducing mechanism to the data recording area is encoded with user's unique information and recorded; a method of reproducing the data from the recording medium; and a method of recording the servo signal in the recording medium.

Abstract: An exemplay object of the present invention is to provide an encryption data recording method, encryption data recording system, and encryption data reproducing system which do not need a specific control to handle key data and are excellent in a security protection property, and furthermore in which a person with a due access right to a recording medium can easily utilize data. The encryption data recording method is characterized in that the method is provided with a data writing step which writes encryption data in at least one recording medium using the encryption data recording system with a plurality of recording media; a key data dividing step which divides the key data of the encryption data into a plurality of key data elements; and a key data element storing step which separately stores each key data element in a plurality of the recording media.

Abstract: A magnetic disk cartridge capable of being loaded into a disk drive comprises a housing, and a magnetic disk, which is accommodated for rotation within the housing. The housing is provided with an opening, which allows a magnetic head of the disk drive to access a surface of the magnetic disk, and a shutter for opening and closing the opening. The housing has an outer peripheral shape composed of a circular arc, which is formed along a contour of the magnetic disk, and two straight lines, which are circumscribed with the circular arc formed along the contour of the magnetic disk and are normal to each other.