Method of magnetic transfer and stopping slave medium rotation
View Patent ↗When magnetically transferring information represented by a pattern of magnetic layer formed on a master information carrier to a disc-like slave medium, an initial DC magnetic field is applied to the slave medium to initially magnetize the slave medium in one direction of concentric recording tracks and a transfer magnetic field is applied to the slave medium in the direction opposite to the direction of the initial-magnetization with the initially-magnetized slave medium held in close contact with the master information carrier. At least one of applying the initial DC magnetic field and applying the transfer magnetic field is effected by applying the magnetic field while the slave medium is being rotated relatively to the magnetic field and stopping the rotation of the slave medium after the intensity of the magnetic field is gradually reduced to not stronger than a predetermined value.
1. A magnetic transfer apparatus to transfer information to a slave medium, said magnetic transfer apparatus comprising:
a slave holder rotated about a rotation axis,
a master information carrier and the slave medium disposed at the slave holder, and
an electromagnet disposed to one side of the slave holder, the electromagnet comprising a first pole and a second pole, the first pole opposingly disposed from the second pole and each of the first and the second poles disposed along a first direction substantially perpendicular to a transfer magnetic field between the first and the second poles and substantially parallel to a radial direction extending out from the rotation axis of the slave holder,
wherein the electromagnet is disposed to only one side of the rotation axis of the slave holder, and
wherein the electromagnet initially applies an initial DC magnetic field to the slave medium in the slave holder to initially magnetize a magnetic layer of the slave medium in one direction of concentric recording tracks,
the transfer magnetic field is applied to the slave medium in another direction opposite to the one direction of the initial-magnetization with the initially-magnetized magnetic layer of the slave medium held in close contact with a magnetic layer on a master information carrier, and at least one of the initial DC magnetic field and the transfer magnetic field is applied while rotating the slave medium relative to the one of the initial DC magnetic field and the transfer magnetic field and the rotation of the slave medium is stopped after an intensity of the one of the initial DC magnetic field and the transfer magnetic field is gradually reduced to not stronger than a predetermined level.