Method and apparatus for magnetic transfer
A magnetic transfer method for performing magnetic transfer is provided wherein magnetic transfer is performed by conjoining and holding in surface-to-surface contact by a holder a transfer master medium, on which transfer data is borne, and a slave medium, to which the transfer data is transferred, and by applying a transfer magnetic field to the transfer master medium held in the holder by a magnet disposed facing to a recordable surface of the slave medium. The holder and the magnet are held movable relative to each other in the direction of the normal to the recordable surface of the slave medium. The distance between the holder and magnet as seen in the direction of the normal is adjusted when magnetic transfer is performed.
1 . A magnetic transfer method for performing magnetic transfer, comprising the steps of: by a holder, conjoining in surface-to-surface contact a transfer master medium, on which transfer data is borne, and a slave medium, to which the transfer data is transferred, to form a conjoined body, and holding the conjoined body; and by a magnet disposed facing to a recordable surface of the slave medium, applying a transfer magnetic field to the transfer master medium held in the holder,
wherein the holder and the magnet are held movable relative to each other in a direction of a normal to a recordable surface of the slave medium; and
wherein a distance between the holder and the magnet as seen in the direction of the normal is adjusted when magnetic transfer is performed.
2 . The magnetic transfer method as defined in claim 1 , wherein the adjustment is performed such that a distance between the holder and the magnet as seen in the direction of the normal is made shorter when a size of a non-recordable region of the slave medium located at a central portion thereof is smaller.
3 . The magnetic transfer method as defined in claim 1 , wherein according to a distance between the holder and the magnet as seen in the direction of the normal, intensity of the transfer magnetic field is adjusted when magnetic transfer is performed.
4 . The magnetic transfer method as defined in claim 1 ,
wherein the holder and the magnet are held movable relative to each other in a radial direction of the slave medium; and
wherein a position of the magnet with respect to the holder as seen in the radial direction is adjusted when magnetic transfer is performed.
5 . The magnetic transfer method as defined in claim 4 , wherein the adjustment is performed such that the magnet is positioned closer to a center of the holder when a size of a non-recordable region of the slave medium located at a central portion thereof is smaller.
6 . The magnetic transfer method as defined in claim 1 ,
wherein the magnet has an N-pole portion and an S-pole portion for producing the transfer magnetic field, the N-pole portion and the S-pole portion being situated close to each other, a spacing between the N-pole portion and the S-pole portion being adjustable; and
wherein the spacing between the N-pole portion and the S-pole portion is adjusted when magnetic transfer is performed.
7 . The magnetic transfer method as defined in claim 6 , wherein the adjustment is performed such that the spacing between the N-pole portion and the S-pole portion is made smaller when a distance between the holder and the magnet as seen in the direction of the normal is shorter.
8 . The magnetic transfer method as defined in claim 1 , wherein the magnet is fixed and the holder is rotatable.
9 . A magnetic transfer method for performing magnetic transfer, comprising the steps of: by a holder, conjoining in surface-to-surface contact a transfer master medium, on which transfer data is borne, and a slave medium, to which the transfer data is transferred, to form a conjoined body, and holding the conjoined body; and by a magnet disposed facing to a recordable surface of the slave medium, applying a transfer magnetic field to the transfer master medium held in the holder,
wherein the holder and the magnet are held movable relative to each other in a radial direction of the slave medium; and
wherein a position of the magnet with respect to the holder as seen in the radial direction is adjusted when magnetic transfer is performed.
10 . A magnetic transfer apparatus comprising: a holder for conjoining in surface-to-surface contact a transfer master medium, on which transfer data is borne, and a slave medium, to which the transfer data is transferred, to form a conjoined body, and holding the conjoined body; and a magnet, disposed facing to a recordable surface of the slave medium, for applying a transfer magnetic field to the transfer master medium held in the holder,
further comprising a normal-direction drive mechanism for holding the holder and the magnet so as to be movable relative to each other in a direction of a normal to a recordable surface of the slave medium such that a distance between the holder and the magnet as seen in the direction of the normal can be adjusted.
11 . The magnetic transfer apparatus as defined in claim 10 , further comprising normal-direction movement control means for controlling the normal-direction drive mechanism such that a distance between the holder and the magnet in the direction of the normal is made shorter when a size of a non-recordable region of the slave medium located at a central portion thereof is smaller.
12 . The magnetic transfer apparatus as defined in claim 10 , further comprising magnetic field intensity adjusting means which can adjust intensity of the transfer magnetic field according to a distance between the holder and the magnet as seen in the direction of the normal.
13 . The magnetic transfer apparatus as defined in claim 10 , further comprising a radial-direction drive mechanism for holding the holder and the magnet so as to be movable relative to each other in a radial direction of the slave medium, such that a position of the magnet with respect to the holder as seen in the radial direction can be adjusted.
14 . The magnetic transfer apparatus as defined in claim 13 , further comprising radial-direction movement control means for controlling the radial-direction drive mechanism such that the magnet is positioned closer to a center of the holder when a size of a non-recordable region of the slave medium located at a central portion thereof is smaller.
15 . A magnetic transfer apparatus comprising: a holder in which a transfer master medium, on which transfer data is borne, and a slave medium, to which the transfer data is transferred, are conjoined and held in surface-to-surface contact; and a magnet, disposed facing to a recordable surface of the slave medium, for applying a transfer magnetic field to the transfer master medium held in the holder,
wherein the magnet has an N-pole portion and an S-pole portion for producing the transfer magnetic field, the N-pole portion and the S-pole portion are situated close to each other, and a spacing between the N-pole portion and the S-pole portion is adjustable.
16 . The magnetic transfer method as defined in claim 1 , further comprising the step of giving a relative rotation movement between a pair of the magnets and the conjoined body constituted by the slave medium and a pair of the transfer master mediums.
17 . The magnetic transfer method as defined in claim 16 , further comprising a transfer preparation step in which a pair of the magnets are disposed at initial positions located at a substantially equal distance, as seen in a direction of thickness of the transfer master medium, from a surface of each of a pair of the master mediums on a side opposite the slave medium.
18 . The magnetic transfer method as defined in claim 16 , wherein phases of the pair of magnets around the rotation axis are matched.
19 . The magnetic transfer apparatus as defined in claim 10 , further comprising rotary drive means for giving a relative rotation movement between the holder and a pair of the magnets, wherein each magnet is disposed at a predetermined distance from a surface of each of a pair of the master mediums on a side opposite the slave medium.
20 . The magnetic transfer apparatus as defined in claim 19 , wherein the pair of magnets are positioned so as to be offset from a rotation axis of the relative rotation movement.