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AssigneeMitsubishi Chemical Corporation
InventorsHiroyuki Ikeda, Youji Arita
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A method for forming a magnetic pattern in a magnetic recording medium, which comprises a step of irradiating energy beams to a magnetic recording medium 101 having a magnetic layer on a substrate via a photomask 102 having a transmitting portion of energy beam and a non-transmitting portion of energy beam to heat locally an irradiated portion of the magnetic layer, and a step of applying an external magnetic field to the magnetic layer wherein the transmitting portion and the non-transmitting portion of the photomask 102 have each a reflectivity of energy beam of 30% or less in at least its one surface facing the magnetic recording medium 101. By using techniques of heating a local portion and applying an external magnetic field in combination, a fine magnetic pattern can be effectively and accurately formed while the production of an interference fringe is suppressed, whereby a magnetic recording medium for high density recording in which the influence of the interference fringe is little, the accuracy of the magnetic pattern is high and the modulation of output signals for the magnetic pattern is small, and a magnetic recording device can be provided economically in a short time.
In a method for forming a magnetic pattern in a magnetic recording medium, comprising a step of irradiating energy beams to a magnetic recording medium having a magnetic layer on a substrate via a photomask having a transmitting portion of energy beam and a non-transmitting portion of energy beam to heat locally an irradiated portion of the magnetic layer, and a step of applying an external magnetic field to the magnetic layer, the method being characterized in that the transmitting portion and the non-transmitting portion of the photomask have each a reflectivity of energy beam of 30% or less in at least its one surface facing the magnetic recording medium.
A magnetic recording medium having a magnetic layer on a substrate wherein a magnetic pattern is formed by a step of irradiating energy beams to a magnetic recording medium via a photomask having a transmitting portion of energy beam and a non-transmitting portion of energy beam to heat locally an irradiated portion of the magnetic layer, and a step of applying an external magnetic field to the magnetic layer, the magnetic recording medium being characterized in that the modulation of the magnetic pattern is 25% or less.
In a photomask used for a method for forming a magnetic pattern in a magnetic recording medium, including a step of irradiating energy beams to a magnetic recording medium having a magnetic layer on a substrate via a photomask having a transmitting portion of energy beam and a non-transmitting portion of energy beam to heat locally an irradiated portion of the magnetic layer, and a step of applying an external magnetic field to the magnetic layer, the photomask being characterized in that the transmitting portion and the non-transmitting portion of the photomask have each a reflectivity of energy beam of 30% or less in at least its one surface facing the magnetic recording medium.
Dependencies are inferred from the claim text.