Matsushita Electric Industrial Co., Ltd.

Matshushita Electric Industrial Co., Ltd.

Nobuyuki Komura

Tatsuaki Ishida

Keizo Miyata

Hideyuki Hashi

Taizou Hamada

Yasuaki Ban

Kiyokazu Tohma

Yuuji Omata

Hiroshi Ryonai

Terumi Yanagi

A master information carrier capable of manufacturing a magnetic recording medium in which a preformat recording of information signals causing no reproduction signal detection errors arising from a pulse shift of a reproduction waveform is performed. A master information carrierhas an array of ferromagnetic thin filmsarranged according to the pattern of information signals and is used for forming magnetizationof a pattern corresponding to the array pattern of the ferromagnetic thin filmin a magnetic recording medium by applying a magnetic field while opposing the master information carrieragainst a magnetic recording medium. Each of the ferromagnetic thin filmsis formed such that each pattern length A becomes equal to a length including a correction amount &#x3b1; in addition to a length a between magnetic transition areasof the magnetizationto be formed in the magnetic recording medium

Master information carrier and method for manufacturing magnetic disc using the same

A master disc capable of conducting a preformat recording by a magnetic transcription without causing any unevenness over an entire magnetic disc is provided. The master disc is provided with a radial land portion where an array of ferromagnetic thin films is formed and a concave portion against the land portion. The land portion and the concave portion are formed such that the land portion is joined with the surface of the magnetic disc when the present magnetic disc is overlapped on the magnetic disc, and that the concave portion is not contacted with the surface of the magnetic disc, and also that a space surrounded by the surface of the magnetic disc and the concave portion is open to air at a peripheral end portion of the magnetic disc.

Master disc and method for manufacturing magnetic disc using the same

A recess for deaeration is formed in the surface of a resist film by using the photolithography technique, a photomask is allowed to come into contact with projections for close contact on both sides or around the recess for deaeration, and evacuation is performed via the recess for deaeration, thereby enhancing close contact between the photomask and the projections for close contact. With the configuration, a resist pattern having an accurate recess while preventing diffraction of light is formed.

Photomask, method of generating resist pattern, and method of fabricating master information carrier

A master information carrier has a shape pattern corresponding to an information signal array to be recorded on a magnetic recording medium, and the shape pattern is provided by arraying a ferromagnetic thin film deposited on a nonmagnetic substrate surface. The ferromagnetic thin film is either a soft magnetic film or semihard magnetic film having not more than 40 kA/m coercive force in track length direction of the information signals, and residual magnetization of the ferromagnetic thin film in the track length direction of the information signals is greater than coercive force of the magnetic recording medium. As a result, a master information carrier with superior magnetic recording performance can be obtained.

Master information medium and method of master information recording

A soft-magnetic multilayer thin film produced by electroplating, wherein an anode-dissolution process is effected by intermittently applying a reverse d.c. bias current with respect to the plating-forward current. Involving the anode-dissolution process allows the formation of a re-dissolution effect layer differing in crystal structure from the plated film layer. A soft-magnetic multilayer thin film characterized by having a multilayer film structure which comprises a plated layer and a re-dissolution effect layer laminated to each other and which the plated layer is at least magnetically isolated. Further, a method of manufacturing a soft-magnetic multilayer thin film having a multilayer film structure magnetically isolated only through plating, which is offered by introducing the anode-dissolution process. In a thin-film magnetic head produced by using a soft-magnetic multilayer thin film, the soft-magnetic multilayer thin film serves as at least one of an upper magnetic core layer and a lower magnetic core layer.

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Kyoto, Japan

Nobuyuki Komura