Patent ID: 7190538

Claim:
A process of producing a preformatted magnetic recording medium, which comprises the steps of: preparing a master carrier for magnetic transfer, preparing a slave medium comprising a non-magnetic support having a magnetic recording layer thereon, initially magnetizing said magnetic recording layer of said slave medium to a predetermined direction, bringing a surface of said master medium into intimate contact with said magnetic recording layer of said slave medium at a predetermined pressure to form a conjoined body, and applying a transfer magnetic field to said conjoined body in a direction opposite to said predetermined direction, thereby obtaining said magnetic recording medium having said recorded data, wherein said master carrier comprises a disk surface having a hill and a valley, which result from a warp of said master carrier; said master carrier has an in-plane distance L (mm) between top of the said hill and bottom of the said valley with respect to said disk surface, a vertical-direction distance H (μm) between said hill and said valley with respect to said disk surface, and a thickness d (mm); and said in-plane distance L (mm), said vertical-direction distance H (μm), and said thickness d (mm) satisfy the following formula: 0.05 ≦H·d 3 /L≦ 0.6