Master information carrier, method for producing the carrier, and method apparatus for writing information into magnetic record medium using the carrier

A hard disc drive comprising a disc type magnetic record medium having a ferromagnetic film or a ferromagnetic coating, wherein the ferromagnetic film or the ferromagnetic coating has a coercive force more than 150 kA/m and has a magnetization pattern of preformat recording magnetically transferred by a method, comprising:

• contacting a surface of a master information carrier with a surface of the magnetic record medium having the ferromagnetic film or the ferromagnetic coating, wherein the master information carrier comprises a substrate and a pattern of a ferromagnetic material provided on the surface of the substrate, the ferromagnetic material having a coercive force in the in-plane direction not more than 40 kA/m, the pattern corresponding to an arrangement of a master information signal, and the magnetic record medium having a coercive force more than 150 kA/m;
• and
• applying a direct exciting field whose intensity is as large as or less than the coercive force of the magnetic record medium to the master information carrier so that the ferromagnetic material of the master information carrier reaches substantial magnetic saturation, thereby magnetically transferring the master information signal into the magnetic record medium as a magnetization pattern from the ferromagnetic material of the master information carrier.

A master information carrier which is put into contact with a surface of a ferromagnetic film or a ferromagnetic coating of a magnetic record medium having a coercive force more than 150 kA/m so as to record a magnetization pattern of a master information signal including at least one of a servo signal, an address information signal and a clock signal into the ferromagnetic film or the ferromagnetic coating, the master information carrier comprising:

• a substrate and a pattern of a ferromagnetic material having a coercive force in the in-plane direction not more than 40 kA/m on the surface of the substrate, the pattern of the ferromagnetic material of the master information carrier corresponding to an arrangement of the master information signal.